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Background: Endovascular aneurysm sealing (EVAS), using the Nellix endovascular aneurysm sealing system, has been associated with high reintervention and migration rates. However, prior reports have suggested that EVAS might be related to a lower all-cause mortality compared with endovascular aneurysm repair (EVAR). In the present study, we examined the 5-year all-cause mortality trends after EVAS and EVAR., Methods: We compared the 333 EVAS patients in the EVAS-1 Nellix U.S. investigational device exemption trial with 16,497 infrarenal EVAR controls from the Vascular Quality Initiative, treated between 2014 and 2016, after applying the exclusion criteria from the investigational device exemption trial (ie, hemodialysis, creatinine >2.0 mg/dL, rupture). As a secondary analysis, we stratified the patients by aneurysm diameter (<5.5 cm and ≥5.5 cm). We calculated propensity scores after adjusting for demographics, comorbidities, and anatomic characteristics and applied inverse probability weighting to compare the risk-adjusted long-term mortality using Kaplan-Meier and Cox regression analyses., Results: After weighting, the EVAS group had experienced similar 5-year mortality compared with the controls from the Vascular Quality Initiative (EVAS vs EVAR, 18% vs 14%; hazard ratio [HR], 1.1; 95% confidence interval [CI], 0.71-1.7; P = .70). The subgroup analysis demonstrated that for patients with an aneurysm diameter of <5.5 cm, EVAS was associated with higher 5-year mortality compared with EVAR (19% vs 11%; HR, 2.4; 95% CI, 1.7-4.7; P = .013). In patients with an aneurysm diameter of ≥5.5 cm, EVAS was associated with lower mortality within the first 2 years (2-year mortality: HR, 0.29; 95% CI, 0.13-0.62; P = .002). However, compared with EVAR, EVAS was associated with higher mortality between 2 and 5 years (HR, 1.9; 95% CI, 1.2-3.0; P = .005), with no mortality difference at 5 years (18% vs 17%; HR, 0.82; 95% CI, 0.4-1.4; P = .46)., Conclusions: Within the overall population, EVAS was associated with similar 5-year mortality compared with EVAR. EVAS was associated with higher mortality for those with small aneurysms (<5.5 cm). For those with larger aneurysms (≥5.5 cm), EVAS was initially associated with lower mortality within the first 2 years, although this advantage was lost thereafter, with higher mortality after 2 years. Future studies are required to evaluate the specific causes of death and to elucidate the potential beneficial mechanism behind sac obliteration that leads to this potential initial survival benefit. This could help guide the development of future grafts with better proximal fixation and sealing that also incorporate sac obliteration., (Copyright © 2022 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Introduction: The current treatment paradigm of abdominal aortic aneurysms (AAA) focuses on observing patients until their disease reaches certain thresholds for intervention, with no preceding treatment available. There is an opportunity to develop novel therapies to prevent further aneurysmal growth and decrease the risk of a highly morbid rupture. We used a porcine model of aortic dilation to assess the ability of human adipose-derived mesenchymal stem cells (MSCs) to attenuate aortic dilation., Materials and Methods: Twelve Yorkshire pigs received periadventitial injections (collagenase and elastase) into a 4-cm segment of infrarenal aorta. Animals were treated with either 1 × 10 6 MSCs placed onto Gelfoam or treated with media as a control. Aortic diameters were measured at the time of surgery and monitored at postoperative day (POD) 7 and 14 with ultrasound. Animals were sacrificed on POD 21. Aortic tissue was harvested for histopathological analyses and immunohistochemistry. Groups were compared with paired t-tests or Mann-Whitney U-tests., Results: All animals survived until POD 21. The mean aortic diameter was reduced in the aortic dilation + MSC treatment group compared to aortic dilation control animals (1.10 ± 0.126 versus 1.48 cm ± 0.151, P < 0.001). Aortic media thickness was reduced in the aortic dilation group compared to the aortic dilation + MSC group (609.14 IQR 445.21-692.93 μm versus 643.55 IQR 560.91-733.88 μm, P = 0.0048). There was a significant decrease in the content of collagen and alpha-smooth muscle actin and elastin perturbation in the aortic dilation group as compared to the aortic dilation + MSC group. Immunohistochemistry demonstrated an increased level of vascular endothelial growth factor, tissue inhibitor of matrix metalloproteinase 1, and tissue inhibitor of matrix metalloproteinase 3 expression in the aorta of aortic dilation + MSC animals., Conclusions: Stem cell therapy suppressed the aortic dilation in a porcine model. Animals from the aortic dilation group showed more diseased gross features, histologic changes, and biochemical properties of the aorta compared to that of the aortic dilation + MSC treated animals. This novel finding should prompt further investigation into translatable drug and cell therapies for aneurysmal disease., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Introduction: Producing a reliable large-animal model of AAA has proven challenging. We sought to create a reproducible swine model of AAA using enzymatic degradation of the aortic wall., Methods: Twelve male Yorkshire swine received periadventitial injections of type 1 collagenase and porcine pancreatic elastase into a 4 cm segment of infrarenal aorta. Nine survived until postoperative day (POD) 21. Aortic growth was monitored at 7 and 14 days using ultrasound. The animals were euthanized on POD 21, and the suprarenal (control) and infrarenal aorta were harvested for analysis, after gross measurement of aortic diameter (AD). Tensile strength was measured and additional segments were collected for histopathological analysis. PCR of matrix metalloproteinases (MMP9) was conducted. Groups were compared with paired t-tests, or ANOVA, where appropriate., Results: Average percent growth of AD at POD 21 for treated segments was 27% versus 4.5% for control tissue. The average difference in AD by subject, was 26.7% (P<0.001). Aortic medial thickness was decreased in treated tissue; 235 μm versus 645 μm (P<0.0001). Quantities of both medial elastin fibers, and smooth muscles cells were decreased in treated tissue; 1.8% compared to 9.9% (P<0.0001), and 24% versus 37.4%, respectively. Tensile strength was also decreased in treated tissue; 16.7 MPa versus 29.5 MPa (P=0.0002). A 12-fold increase in expression of MMP9 mRNA was also demonstrated in aneurysmal tissue (P=0.002) CONCLUSION: A reproducible, large-animal model of AAA, with anatomical, histopathological, and biomechanical properties that are clinically translatable, can be achieved with extraluminal enzymatic degradation., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objective: Adverse outcomes observed late in the Nellix EndoVascular Aneurysm Sealing (EVAS) System (Endologix, Inc, Irvine, Calif) investigational device exemption trial prompted refinement of the anatomic instructions for use (IFU). This study aimed to investigate the association of procedural factors during Nellix endograft deployment and patient outcomes., Methods: We retrospectively reviewed 1-month imaging of 333 patients enrolled in the prospective, multicenter EVAS investigational device exemption trial between January 2014 and September 2016. Initial observations of those patients who met revised anatomic IFU yet still experienced late adverse events suggested that inadequate seal and low graft placement were common among these patients. Key procedural variables identified from a univariate analysis were applied to construct four cohorts stratified by procedural technical performance (technically adequate [P+] or technically inadequate [P-]) and the revised anatomic indications for use (anatomically within IFU [A+] or anatomically outside of IFU [A-]) and to compare them for aneurysm-related outcomes. A logistic regression analysis was performed to identify significant predictors of sac expansion or migration., Results: Proximal and distal seal zones and low graft placement were identified by logistic regression analysis as significant predictors of sac expansion or migration. Accordingly, acquisition of ≥10-mm proximal and distal seal zones and the position of the lowest stent within 10 mm of the lowest renal artery were clinically justified as thresholds for a technically adequate procedure. Patients who did not achieve these parameters were deemed to have a technically inadequate procedure. By use of the proposed procedural adequacy criteria and established anatomic criteria, patients were stratified into four cohorts: A+/P+ (n = 77), A+/P- (n = 54), A-/P+ (n = 71), and A-/P- (n = 131). Three-year estimates of freedom from migration of 10 mm were 98.6% in A+/P+, 95.9% in A+/P-, 85.8% in A-/P+, and 80.1% in A-/P-; freedom from type IA endoleak estimates were 98.6% in A+/P+, 100% in A+/P-, 96.4% in A-/ P+, and 90.3% in A-/P- cohorts. Freedom from sac expansion and secondary intervention were 96.9% and 90.6% in A+/P+, 86.0% and 93.6% in A+/P-, 87.1% and 83.1% in A-/P+, and 80.5% and 79.8% in A-/P- groups, respectively. Two early deaths (aneurysm-related mortality) on days 4 and 12 postoperatively were reported within the A+/P- group. Kaplan-Meier estimates of freedom from all-cause mortality and aneurysm-related mortality at 3 years were similar between cohorts., Conclusions: This post hoc analysis suggests that achieving a 10-mm proximal and distal seal with adequate positioning of the endograft with respect to the renal arteries is associated with improved patient outcomes., (Copyright © 2019. Published by Elsevier Inc.)

Background: Endovascular aneurysm repair (EVAR) is the dominant treatment modality for abdominal aortic aneurysm (AAA). Periprocedural risks are low, and cardiovascular events are the principle determinants of long-term survival. Recently, the concept of endovascular aneurysm sealing (EVAS) has been introduced into clinical investigation. In previous cohort studies, EVAS has been associated with a lower all-cause mortality than expected despite device issues. We used a propensity weighted approach to investigate whether EVAS was associated with lower all-cause mortality after aneurysm repair., Methods: We compared 333 patients in the Nellix United States Investigational Device Exemption trial to 15,431 controls from the Vascular Quality Initiative between 2014 and 2016 after applying the exclusion criteria from the investigational device exemption (hemodialysis, creatinine > 2.0 mg/dL, or rupture). We calculated propensity scores and applied inverse probability weighting to compare risk adjusted medium-term survival using Kaplan-Meier and Cox regression., Results: After weighting, patients treated with the Nellix EVAS system experienced higher 3-year survival than controls from the Vascular Quality Initiative (93% vs. 88%, respectively). This corresponded to a 41% lower risk of mortality for EVAS compared with EVAR (HR 0.59 [0.38-0.92], P = 0.02). Subgroup analysis demonstrated that the association between EVAS and higher survival was strongest in the subgroup of patients with aneurysms over 5.5 cm (P for interaction < 0.001). In this subgroup, EVAS patients experienced half the rate of mortality as those patients treated with EVAR, with 3-year survival of 92% compared with 86% (HR 0.5 [0.3-0.9], P = 0.02)., Conclusions: In this select group of patients, EVAS was associated with higher medium-term survival than traditional EVAR. Although issues with the device have recently surfaced, this exploratory analysis shows that the concept of sac sealing may hold promise. Further study is needed to confirm this finding and determine whether EVAS is associated with lower rates of cardiovascular events., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: The American College of Surgeons' National Quality Improvement Program (NSQIP) database can be used to assess trends and outcomes of ruptured abdominal aortic aneurysm (rAAA) repair. The purpose of this study is to examine the morbidity and mortality for ruptured endovascular (rEVAR) and ruptured open (rOPEN) aneurysm repair compared with elective endovascular (EVAR) and elective open (OPEN) aneurysm repair., Methods: Ruptured and nonruptured abdominal aortic aneurysms were identified from the NSQIP database between 2008 and 2016. Data regarding demographics and comorbidities, 30-day mortality, and postoperative complications were collected for rEVAR, rOPEN, EVAR, and OPEN cases., Results: There were 43,105 AAAs, 34,177 (79.28%) EVARs, and 8928 (20.71%) OPENs. There were 3806 rAAAs, 1843 (48.42%) rEVARs, and 1963 (51.58%) rOPENs. The incidence of rEVAR repair lagged behind EVAR considerably. Mortality for rOPEN was 575 (29.29%) and 344 (18.66%) for rEVAR. No difference between the ratio of men to women in rOPEN vs rEVAR was noted. There was a significant increase in mortality for women vs men undergoing rEVAR (P = .0362). No difference in mortality existed between women vs men undergoing rOPEN (P = .0639). There was no difference in the percentage of hypotensive cases undergoing rEVAR vs rOPEN (P =.1873). For all rAAAs with hypotension, rOPEN had an increased mortality compared to rEVAR (P = .0004). There were 20 (3.11%) rEVAR and 40 (8.00%) rOPEN cases with lower extremity ischemia. rOPEN conferred a significant increase in lower extremity ischemia (P = .0002). There were 46 (7.15%) rEVAR and 60 (12.00%) rOPEN cases of ischemic colitis. rOPEN had a significant increase in ischemic colitis (P = .0052)., Conclusions: NSQIP data, over 9 years, demonstrate an increased morbidity and mortality associated with open vs endovascular repair of rAAAs. A great disparity exists between the proportion of rEVAR and rOPEN to EVAR and OPEN. The lagging use of endovascular repair of rAAAs must be further explored., (Copyright © 2019 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Background: The Nellix System (Endologix, Inc, Irvine, Calif) for endovascular aneurysm sealing (EVAS) is a novel approach to abdominal aortic aneurysm treatment and conceptually different from endovascular aneurysm repair, whereby polymer is employed to fill and actively manage the abdominal aortic aneurysm sac. One-year safety and effectiveness results of the Nellix pivotal trial demonstrated encouraging outcomes with very low morbidity and mortality and high procedural and treatment success. Two-year imaging revealed a signal of migration, leading to a field safety notification issued by the manufacturer on October 21, 2016, and a dedicated root cause analysis, resulting in refinements to the instructions for use (IFU). We report the 2-year results of the investigational device exemption pivotal trial stratified according to the new and original criteria for selection of patients., Methods: Comprehensive engineering evaluations, statistical analyses, and clinical assessments were conducted looking at patients enrolled in the pivotal trial (N = 150), roll-in cohort (N = 29), and continued access program (N = 154). All patients in all cohorts were treated on-IFU at the time of enrollment. Logistic regression models supported the mechanism that migration with Nellix is associated with a small aortic flow lumen relative to a large aneurysm thrombus burden and large aortic neck diameters. Based on these findings, refinements to the IFU criteria were applied, excluding patients with a thrombus index (maximum aneurysm sac/maximum flow lumen diameter) >1.4, aortic neck diameter >28 mm, and aortic neck conicity (>10% diameter change along the infrarenal neck) and requiring a 10-mm distal seal zone in the iliac artery., Results: Freedom from all-cause mortality at 2 years was 94%. Patient outcomes were then stratified on the refined morphologic criteria and analyzed retrospectively. Two-year freedom from composite endoleak was high among both cohorts (95% on-IFU vs 92% off-IFU). Freedom from migration was 97.7% on-IFU vs 93.2% off-IFU (P = .0125). Freedom from aneurysm enlargement was 98.1% on-IFU vs 93.5% off-IFU (P value is not available because of failure of log-rank test assumptions). Composite freedom from migration, type IA endoleak, or aneurysm expansion was 95.9% among the on-IFU cohort vs 85.1% in the off-IFU cohort (P = .0017)., Conclusions: Consistent with the introduction of a novel therapy, the presentation of failure modes of EVAS over time was inevitable. Using detailed imaging as well as engineering and statistical analysis, we were able to understand risk factors for adverse events specific to EVAS and defined those patients best suited for Nellix. With this EVAS-specific approach to defining IFU, on-IFU patients were identified as those with large aneurysms with little thrombus that would be prone to type II endoleaks and sac expansion with traditional devices. When treated with Nellix, these patients were predicted to experience exceptional results, especially with regard to a low composite endoleak rate and low all-cause mortality., (Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Background: To describe a large single-institutional experience in managing challenging access situations during endovascular aneurysm repair (EVAR)., Methods: Data from all patients undergoing EVAR at a tertiary academic medical center between 2009 and 2013 were collected retrospectively, including demographics, size of iliac arteries, type of device used, approach to managing difficult access (DA), and outcomes. The median follow-up was 38 months. DA was defined as iliac arteries with a diameter of less than 7 mm bilaterally. Fenestrated and snorkel repairs were excluded., Results: Of 400 EVARs performed during the study period, 191 (48%) were done in patients with DA. Of the DA patients, 35 (18.3%) underwent 42 adjuncts before the introduction of the main body device: including 15 dilators, 11 balloon angioplasties, 9 aortouniiliac devices, 3 SoloPath sheaths, 1 retroperitoneal cutdown, and 3 iliac stents. In another 29 patients, iliac stents were used to correct stenoses or kinks in the limbs after EVAR devices were deployed. The average diameter of the iliac artery used to deliver main body component was 4.6 mm in the group of patients requiring adjuncts and 5.4 mm in the remainder of the patients with small iliac arteries (P = 0.008). The median size of the main body device was 28 mm. Two cases were aborted due to inability to deliver the device. Other complications included 7 (3.6%) iliac ruptures, 3 (1.6%) instances of limb ischemia, and 5 (2.6%) patients needed early reoperation (within 30 days). Two patients (1%) had type I endoleaks at the conclusion of EVAR. During follow-up, 12 (6.3%) patients required EVAR revisions. Seven patients (3.6%) had limb thrombosis which occurred only in patients who did not have adjective procedures during the initial EVAR. Limb thrombosis and rate of revisions in patients with DA were not significantly different from the rates observed in non-DA patients. Perioperative mortality after elective repairs was 1.6% in DA patients and 0% in non-DA patients (P = 0.12)., Conclusions: EVAR can be successfully performed in patients with bilateral small iliac arteries. Adjunctive procedures might increase the technical success rate of EVAR in these patients and should definitely be considered in patients with iliac arteries less than 5 mm in diameter. Next generation and "low-profile" devices might minimize the need for adjunctive procedures and facilitate EVAR in these patients., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Objective: The Nellix EndoVascular Aneurysm Sealing (EVAS) System (Endologix, Inc, Irvine, Calif) is a novel approach to abdominal aortic aneurysm (AAA) treatment whereby polymer is used to fill the AAA sac. We report 1-year results of the investigational device exemption pivotal trial., Methods: Eligible patients were treated at 30 sites in the United States and Europe. Inclusion criteria required an asymptomatic infrarenal AAA, with a neck length ≥10 mm and ≤60° angle, iliac artery blood lumen diameter 9 to 35 mm, access artery diameter ≥6 mm, and serum creatinine ≤2 mg/dL. Follow-up included computed tomography angiography scans at 30 days, 6 months, and 1 year that were evaluated by a core laboratory. The primary safety end point was 30-day major adverse events (MAEs), which were compared with a performance goal of <56% (the Society for Vascular Surgery open repair control group rate). The primary effectiveness end point was treatment success at 1 year, which was compared with a performance goal of >80%. Treatment success required procedural technical success and absence of AAA rupture during follow-up, conversion to open surgical repair, endoleak (type I or III) at 1 year, migration >10 mm causing complications or requiring secondary intervention, aneurysm enlargement, or secondary procedures through 1 year for resolution of endoleak, device obstruction or occlusion, or device defect., Results: Of 150 treated patients, 149 (99.3%) completed 1-year follow-up. The MAEs rate at 30 days was 2.7% (95% confidence interval, 0.7%-6.7%), satisfying the primary safety end point (<56%). The 1-year treatment success was 94% (95% confidence interval, 88.6%-97.4%), achieving the primary effectiveness end point (>80%). At 1 year, key secondary outcomes included 6.7% MAEs, 4.7% serious device-related events, 1.3% AAA-related mortality, 3.7% secondary interventions, and 0.7% surgical conversions. MAEs through 1 year included death (n = 6), stroke (n = 3), bowel ischemia (n = 2), renal failure (n = 2), respiratory failure (n = 2), and myocardial infarction (n =1). One iatrogenic AAA rupture occurred and one AAA rupture was reported during follow-up. AAA sac enlargement (>5 mm) was 1.5% at 1 year. Endoleaks were present in four patients (3.1%) at 1 year (1 type Ib and 3 type II). Migration >10 mm occurred in three patients (2.3%), but none required secondary intervention., Conclusions: Outcomes with this novel endovascular therapy for AAA, the Nellix EVAS System, are encouraging. The primary safety and effectiveness end points have been met. Low morbidity, low mortality, and high procedural and treatment success were achieved despite the inevitability of a learning curve and unique risks associated with a new device and technique. Long-term follow-up is in progress., (Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Recent advances in endovascular aneurysm repair have overcome substantial anatomic barriers associated with short and challenging necks. With greater range to treat more difficult anatomy from an endovascular approach, one would assume the need of open surgical repair (OSR) would be diminished. The purpose of our study was to determine the need for OSR for abdominal aortic aneurysms, in a tertiary academic setting, with a moderate volume (10-15 cases/year) of fenestrated endografting being performed., Methods: An Institutional Review Board approved retrospective review was performed of all patients who underwent elective aortic aneurysm repair between January 2010 and July 2014. Computed tomography scans for patients who underwent OSR were reviewed and anatomic characteristics obtained. Instructions for use of (IFU) a commercially available fenestrated device (Cook Medical, Bloomington, Ind) were used to determine if open repair patients had anatomy amenable to advanced endovascular repair., Results: During the study interval, 415 patients underwent abdominal aortic aneurysm repair. Of those patients who underwent elective aneurysm repair, 105 patients had OSR. The study subsequently excluded 11 patients because they underwent secondary interventions after a failed endovascular repair and thus were not further evaluated. Also excluded were 18 patients who had OSR for an emergency intervention. The remaining 76 patients (35 female, 41 male; average age, 72 ± 8 years) had OSR and were outside the IFU of the fenestrated endovascular aneurysm repair (FEVAR) device. The average diameter of the abdominal aorta was 5.9 cm. Indications for OSR were an aneurysm neck <4 mm (71%), inclusion of at least 1 visceral vessel (69.7%), unilateral iliac artery aneurysms (15.5%), bilateral iliac artery aneurysms (14.3%), iliac artery tortuosity >40° of angulation (37.6%), extensive aortic thrombus (23.2%), and aortic neck angulation >45° (11.8%). Rejected patients had an average of 1.7 ± 0.8 anatomic constraints (range 1-4) that prevented use of the FEVAR device., Conclusions: With evidence to support the strict adherence to IFU protocols of the FEVAR device in patients, our institution's practice has been to continue to perform open abdominal aortic aneurysm repair for patients with anatomy outside device protocols. Although it was thought that the decreased requirement of aortic neck required to deploy an endograft would lead to an increased patient population amenable to endovascular repair, there is still a clinically significant need for open aortic surgery., (Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Endovascular aneurysm sealing (EVAS) using the Nellix system is a new and different method of abdominal aortic aneurysm repair. Normal postoperative imaging has unique appearances that change with time; complications also have different and specific appearances. This consensus document on the imaging findings after Nellix EVAS is based on the collective experience of the sites involved in the Nellix EVAS Global Forward Registry and the US Investigational Device Exemption Trial. The normal findings on computed tomography (CT), duplex ultrasound, magnetic resonance imaging, and plain radiography are described. With time, endobag appearances change on CT due to contrast migration to the margins of the hydrogel polymer within the endobag. Air within the endobag also has unique appearances that change over time. Among the complications after Nellix EVAS, type I endoleak usually presents as a curvilinear area of flow between the endobag and aortic wall, while type II endoleak is typically small and usually occurs where an aortic branch artery lies adjacent to an irregular aortic blood lumen that is not completely filled by the endobag. Procedural aortic injury is an uncommon but important complication that occurs as a result of overfilling of the endobags during Nellix EVAS. The optimum imaging surveillance algorithm after Nellix EVAS has yet to be defined but is largely CT-based, especially in the first year postprocedure. However, duplex ultrasound also appears to be a sensitive modality in identifying normal appearances and complications., (© The Author(s) 2015.)

Objective: The Nellix EndoVascular Aneurysm Sealing system (Endologix, Inc, Irvine, Calif) is a novel approach to abdominal aortic aneurysm (AAA) endovascular repair whereby biocompatible polymer is employed to exclude and to seal the AAA sac. We report 30-day results of the U.S. pivotal trial., Methods: Consecutive, eligible, consenting patients were enrolled at 29 sites in the United States and Europe. Inclusion criteria required an asymptomatic infrarenal AAA, with aortic neck length ≥10 mm and angle to the sac ≤60 degrees, aortic neck diameter of 18 to 32 mm, aneurysm blood lumen diameter ≤6 cm, common iliac artery lumen diameter of 9 to 35 mm, access artery diameter ≥6 mm, and serum creatinine level ≤2 mg/dL. Follow-up at 30 days included clinical assessment and computed tomography angiography evaluation of endoleaks and device integrity as assessed by a core laboratory. The primary safety end point is the incidence of independently adjudicated 30-day major adverse events (MAEs), with success defined as superiority with reference to the Society for Vascular Surgery open repair control group (56%)., Results: Between January and November 2014, 150 trial patients having a mean AAA diameter of 5.8 cm were enrolled and treated with the Nellix system with 100% procedural success. One early death (0.7%) occurred secondary to multisystem organ failure. All 149 surviving patients completed 30-day follow-up. There were no aneurysm ruptures, conversions, limb thromboses, stent fractures, or stent kinking. Five early MAEs occurred in four patients (2.7%) and included one death, bowel ischemia (1), renal failure (2), and respiratory failure (1). One (0.7%) secondary intervention to treat inadvertent coverage of a renal artery was performed. The core laboratory identified nine (6%) endoleaks (one type I, eight type II) on 30-day computed tomography angiography. Freedom from MAE was 97.3% (95% confidence interval, 93.3%-99.0%)., Conclusions: In selected patients, perioperative outcomes with the Nellix system for endovascular aneurysm sealing are encouraging, with very low 30-day morbidity and mortality and high procedural success. The primary safety end point has been achieved. Longer term follow-up is in progress., (Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: To examine the results of open or endovascular abdominal aortic aneurysm (AAA) repair following prior open or endovascular thoracic aortic surgery., Methods: A retrospective review of all patients who underwent AAA repair in a delayed fashion following prior thoracic aortic surgery at a single university hospital between 1999 and 2011 was performed., Results: Thirteen patients underwent AAA repair following prior thoracic aortic repair. Mean age was 68.9 ± 6.9 years and 77% (n = 10) were male. Three patients experienced transient delayed-onset spinal cord ischemia (SCI) following initial thoracic surgery. Mean time interval between initial thoracic aortic surgery and subsequent AAA repair was 2.0 ± 1.8 years. Overall rate of SCI and 30-day mortality after delayed AAA repair was 0%., Conclusions: This series does not demonstrate any evidence of increased risk of perioperative mortality or SCI in patients undergoing delayed AAA repair after prior thoracic aortic surgery.

Objectives: The purpose of this study was to identify predictors of decreased survival after open abdominal aortic aneurysm (AAA) repair at a single university hospital., Methods: Patients undergoing open AAA repair from June 2003 to June 2009 were identified. Primary outcomes were 30-day and 5-year survival. Preoperative, intraoperative, and postoperative variables were assessed for their influence on outcomes using univariate and multivariate analysis, as appropriate. One- and 5-year survival were determined by Kaplan-Meier analysis., Results: Four hundred eight patients (289 men; 70.8%) with a mean age of 72.4 ± 8.3 years underwent open AAA repair. Sixty-seven patients (16.4%) underwent nonelective repair. The clamp site was infrarenal in 137 patients (33.6%), suprarenal in 97 patients (23.8%), and supraceliac in 174 patients (42.6%). Thirty-day survival was 95.6%. One- and 5-year survival were 90.0% ± 1.5% and 65.1% ± 3.0%, respectively. Seventy-nine patients (19.4%) had decreased renal function postoperatively compared to preoperatively, 71 patients (17.4%) sustained cardiac complications, and 45 patients (11.0%) sustained pulmonary complications. Patients with chronic obstructive pulmonary disease (91.9% vs 97.2%; P = .004) and chronic renal insufficiency (92.0% vs 98.3%; P = .009) had decreased 30-day survival. Patients with chronic obstructive pulmonary disease (55.8% ± 5.8% vs 67.3% ± 3.6%; P = .013), chronic renal insufficiency (51.2% ± 5.2% vs 72.8% ± 3.7%; P = .043), and cerebrovascular disease (46.8% ± 7.4% vs 67.4% ± 3.4%; P = .003) had decreased 5-year survival. Patients who had decreased postoperative renal function (41.0% ± 7.4% vs 72.2% ± 3.4%; P = .004), and patients who sustained pulmonary complications (45.6% ± 8.8% vs 66.3% ± 3.3%; P = .042) had worse 5-year survival., Conclusions: Open AAA repair can be done with low morbidity and mortality in the era of endovascular aneurysm repair. Careful consideration should be given to preoperative optimization and perioperative care in patients with chronic obstructive pulmonary disease, chronic renal insufficiency, and cerebrovascular disease. Postoperative decrease in renal function and pulmonary complication portend decreased 5-year survival; strategies to ameliorate these factors should be sought., (Copyright © 2011 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Objectives: To evaluate indications for, operative strategy during, and outcomes following late open surgical conversion following endovascular aneurysm repair (EVAR)., Methods: Between 2002 and 2009, patients undergoing open abdominal aortic aneurysm repair at a university hospital were entered prospectively into a database which was examined to identify patients undergoing open conversion >30 days after EVAR., Results: Over 7 years, 21 patients required late open conversion of EVAR. The average patient age was 75 years (range, 59-88), and there were 16 male (76%) patients. The mean interval to conversion was 33.4 months (range, 2-73). Eight patients (38%) presented with proximal type I endoleak; 4 patients (19%) presented with type II endoleak and aneurysm expansion; 5 patients (24%) presented with graft migration and aneurysm expansion; and 5 patients (24%) presented with de novo visceral aneurysms. Rupture (1) and infection (1) were also observed. There were five (24%) emergent cases. Most patients (12/21, 57%) had more than one reason for conversion. There were no perioperative deaths; three patients (14%) had major complications. Grafts requiring conversion were AneuRx (6; Medtronic AVE, Santa Rosa, Calif), Zenith (6; Cook Inc, Bloomington, Ind), Talent (3; Medtronic), Excluder (2; W. L. Gore, Flagstaff, Ariz), Anaconda (1; TERUMO Corp, Ann Arbor, Mich), Ancure (1; Guidant, Menlo Park, Calif), Quantum LP (1; Cordis Corp, Miami Lakes, Fla), and Powerlink (1; Endologix, Irvine, Calif). The surgical approach was retroperitoneal in 16 (76%) and transperitoneal in four (19%) patients. Initial proximal aortic control was supraceliac (9/21), suprarenal (7/21), or infrarenal (5/21), with stepwise distal clamping to reduce ischemic time. Complete endograft removal was performed in 17/21 patients; in 4/21 the distal anastomosis was performed to the endograft after proximal segment explantation. Reconstruction was completed with tube (19/21) or aortoiliac (2/21) grafts; in one case, homograft was used. Mean intraoperative blood loss was 1.9 L (range, 0.4-6.5 L), mean intensive care unit (ICU) stay was 3 days (range, 2-6), and the mean hospital stay was 10 days (range, 4-39)., Conclusions: While technically challenging, delayed open conversion of EVAR can be accomplished with low morbidity and mortality in both the elective and emergent settings. These results reinforce the justification for long-term surveillance of endografts following EVAR., (Copyright © 2011 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Objective: The purpose of this study was to determine the feasibility of open abdominal aortic aneurysm (AAA) repair in octogenarians during a time period of multiple commercially available endografts, in which only proximal aneurysms or the most challenging anatomy are not stented., Methods: A retrospective review was performed of all patients aged ≥ 80 years undergoing open AAA repair over a 7-year period (2003-2009) at a single academic medical center. Demographic data, aneurysm characteristics, comorbidities, operative results, perioperative complications, length of stay, and late outcomes were analyzed., Results: Sixty-five patients were identified (men, n = 27) with a median age of 82 years (80-89 years old). Mean aneurysm size was 6.7 cm. Morphology consisted of type IV thoracoabdominal (n = 19), suprarenal (n = 14), pararenal (n = 19), and infrarenal (n = 13). Eighty-five percent of cases were performed electively. A tube graft was used in 58 patients, and the left renal artery was bypassed in 33 patients. Fifty-two patients required a suprarenal or supraceliac clamp, with a mean proximal clamp time of 22 minutes. Mean estimated blood loss was 1800 mL. Mortality was 6% at 30 days. Overall morbidity was 42%, most commonly an arrhythmia (25%). Major complication rate was 18%. Median intensive care unit (ICU) and hospital length of stay was 3 and 9 days, respectively. Sixty-one percent of patients were discharged directly home. Six patients developed acute renal failure, although none progressed to dialysis. Mean serum creatinine was 1.3 mg/dL preoperatively and 1.5 mg/dL at discharge. One patient developed bowel necrosis (sigmoid colon) requiring resection. Follow-up ranged from 1 to 81 months (mean, 24 months). Three-year survival was 79%., Conclusion: With an increasing population of elderly patients, vascular surgeons are continually confronted with patients over 80 years of age. Our patients consisted of those not anatomically suitable for endovascular aortic aneurysm repair. Despite a predominance of proximal aneurysms, our results demonstrate excellent rates of morbidity and mortality. Thus, open AAA repair can be done safely and effectively in octogenarians, and age alone should not exclude this form of repair., (Copyright © 2011 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Objective: Current long-term surveillance after endovascular abdominal aortic aneurysm repair (EVAR) is based on high-resolution contrast-enhanced computed tomography (CT) scans at scheduled, lifelong intervals. The cancer and nephrotoxicity risks of interval CT scanning and prolonged radiation exposure are concerning. We sought to determine if surveillance CT angiography (CTA) can be safely reduced., Methods: From July 2000 to November 2007, 345 patients were enrolled in U.S. Food and Drug Administration trials of the Powerlink System (Endologix, Irvine, Calif). An independent core laboratory analyzed 1519 post-EVAR CT scans (N=1519) to 5 years to evaluate aneurysm size, migration, presence of endoleak, and evidence of graft obstruction. Analyses were conducted to determine the value of the initial CTA scan in predicting future secondary procedures in enrolled patients., Results: At any time during follow-up, CTA identified endoleak in 123 patients (36%), with 95% of endoleaks being type II. In addition, 49 patients underwent 72 secondary procedures at a mean of 22±21 months (range, 2-2007 days) after initial EVAR. These were based on clinical identification of limb ischemia in 13 interventions (18%) or core laboratory identification of abnormal CT finding in 58 interventions (81%). Of the 58 core laboratory identified findings, the inciting abnormality was present on the initial postoperative scan in 49 (84%). Of the remaining nine CT-driven procedures, three (5.2%) were due to late sac expansion attributed to type II endoleak (n=2) or endotension (n=1); two (3.4%) were for prophylactic reasons in the absence of endoleak; and four (6.8%) were in patients with type II endoleak not observed by the core laboratory and without sac expansion. The negative predictive value of the initial postoperative CTA for the need for a secondary procedure is therefore 96.4%, which can be improved to 97.6% with duplex ultrasound surveillance to detect sac expansion. Thus, a negative initial postoperative CTA is highly predictive of long-term freedom from secondary intervention., Conclusions: Among enrolled patients with suitable anatomy for EVAR, most abnormalities that result in a secondary procedure are detected on the initial postoperative CTA or present with clinical symptoms. Long-term surveillance CTA may therefore be replaced by duplex ultrasound imaging if the initial postoperative CTA shows no abnormalities., (Copyright © 2010 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Purpose: To report the contemporary controlled trial experience with the fully supported unibody Powerlink stent-graft for endovascular treatment of abdominal aortic aneurysm (AAA)., Methods: Between 2000 and 2008, 3 prospective multicenter trials of the Powerlink system evaluated 157 AAA patients (141 men; mean age 72.0+/-9.1 years) with mean AAA sac diameter of 5.6+/-0.9 cm who received a bifurcated stent-graft featuring anatomical fixation at the aortoiliac bifurcation and proximal sealing with extension stent-grafts as needed. Challenging infrarenal aortic neck anatomy was present in 83% of patients. Postoperative follow-up occurred at defined intervals to 5 years., Results: Technical success was achieved in 99% of patients. Aneurysm exclusion was achieved in all patients over a mean procedure time of 132+/-58 minutes. No aneurysm-related deaths, ruptures, conversions, or migrations have been observed to current follow-up as these aneurysms have continued to remodel, with > or =92% of patients free from sac growth., Conclusion: The implant technique of placing a fully-supported unibody stent-graft at the aortoiliac bifurcation with proximal sealing appears to safely and effectively reline the aorta and exclude aneurysms. Results from controlled clinical trial experience suggest this algorithm can provide stable, secure fixation for patients with challenging infrarenal aortic neck anatomy.

Purpose: Endovascular stent graft repair of abdominal aortic aneurysms (AAA) with the Endologix Powerlink System (Endologix, Inc, Irvine, Calif) has been shown to be a safe and effective alternative to open surgery in patients having an aortic neck diameter of up to 26 mm. We assessed the safety and effectiveness of AAA repair in patients with wide aortic necks (up to 32 mm in diameter) using the Powerlink XL System., Methods: Between September 2005 and June 2008, a prospective, multicenter, pivotal US Food and Drug Administration trial of the Powerlink XL System for endovascular aneurysm repair was conducted at 13 centers. Using a sizing algorithm based on computed tomography scan (CT)-based measurements, a total of 78 patients (N = 60 [pivotal trial]; N = 18 [continued access]) presenting with AAA and an infrarenal aortic neck up to 32 mm in diameter received a bifurcated stent graft via anatomical fixation at the aortoiliac bifurcation and proximal sealing with a Powerlink XL infrarenal proximal extension stent graft. Postoperatively, results were assessed with contrast-enhanced CT scans and abdominal x-rays at one, six, and 12 months, with continued annual follow-up to five years., Results: Predominantly male (91%), patients presented at a mean age of 73 +/- 8.6 years with mean maximum aortic neck and AAA diameters of 31 +/- 1.9 mm (range, 25 to 32 mm) and 5.7 +/- 1.0 cm (range, 4.3 to 10 cm), respectively. Challenging infrarenal aortic neck anatomy, defined as the presence of severe thrombus and/or reverse taper, was present in 85% of patients. Technical success was achieved in 98.7% of patients, with one patient requiring femoral-femoral bypass intraoperatively. Aneurysm exclusion was achieved in 100% of patients over a mean procedure time of 129 +/- 66 minutes. Patients were discharged at a mean of 2.2 days postoperatively. At the one-month CT scan, the independent core lab identified a Type II endoleak in 13 patients, distal Type I and Type II endoleak in one patient, and unknown endoleak in three patients. At 30 days, there were no deaths, conversions, ruptures, or migrations. Through one year follow-up, Type II endoleak predominated (9/10 patients with endoleak), with one proximal Type I and no Type III, IV, or unknown endoleak; no conversions, ruptures, or migrations have been observed. The one-year all-cause mortality rate was 6.4%, with 100% freedom from aneurysm-related mortality. Secondary procedures were performed within one year in five patients (6.4%) for treatment of proximal Type I endoleak (n = 2), proximal Type I/Type II endoleak (n = 1), and distal Type I endoleak (n = 2). Reduced or stable aneurysm sac diameter at one year is observed in 96% of patients., Conclusions: The combination of an anatomically-fixed Powerlink bifurcated stent graft and a Powerlink XL infrarenal proximal extension appears safe and effectively excludes aneurysms in patients with wide aortic necks. These results suggest that fixation at the aortic bifurcation can provide secure fixation for patients with large diameter diseased proximal aortic necks.

Objective: To determine whether there is a difference in outcome between endovascular repair of abdominal aortic aneurysm (EVAR) of small versus large aneurysms., Methods: A total of 192 patients from the Power-link trial were subdivided into small abdominal aortic aneurysms (AAA; 5 cm) groups. Demographics, perioperative morbidity, mortality, overall survival, and freedom from major adverse events, endoleak, aneurysm-related death, migration, and secondary procedures were assessed. Aneurysmal involvement of the iliacs as well as neck length and angulation was compared between groups., Results: Perioperative morbidity (P = 1.000), mortality (P = .4603), and extent of iliac involvement did not differ between groups (P = .2260). The necks in small AAA were longer (P = .0028) and less angulated (P < .0001). There was no difference in overall survival (P = .6066), freedom from major adverse events (P = .7842), endoleak, (P = .1832), migration (P = .5765), aneurysm-related death (P = .4728), or need for secondary procedures (P = .2323)., Conclusion: Under controlled conditions of patient and device selection, there is no significant difference in outcome for EVAR of small versus large AAA.

Objective: We compared the results of endovascular repair using the Powerlink endovascular graft with conventional open abdominal aortic aneurysm repair through a 6-year follow-up period., Methods: Two hundred fifty-eight patients with abdominal aortic aneurysms were prospectively enrolled in a multicenter trial and underwent endovascular repair (N = 192) or conventional open surgery (N = 66). All endovascular repairs were approached through a surgically exposed femoral artery and a percutaneously accessed femoral artery. Study endpoints included all-cause mortality and morbidity. Follow-up imaging consisted of contrast-enhanced CT scans and plain abdominal x-rays at 1, 6, 12 months, and annually postoperatively., Results: Technical success was achieved in 97.9% of test patients, with four failed insertions (three early conversions because of deployment issues, one access failure). Mean follow-up was 4.1 +/- 1.7 years (test group) and 3.1 +/- 1.9 years (control group). Perioperative morbidity and mortality were significantly reduced in the test group compared with the control group (P < .05). At 6 years, all-cause mortality and morbidity was no different in the Powerlink group compared with the open repair group. There were no reported stent fractures, graft disruptions, or aneurysm ruptures. Core laboratory-reported endoleaks included proximal or distal type I (n = 1) and type I/II (n = 3), with no type III or type IV endoleaks. One explant (0.5%) was undertaken to resolve a refractory type I endoleak. A total of 37 secondary procedures were performed in 26 patients to treat site-reported endoleak (n = 26; 7 for type I and 19 for type II), graft limb occlusion (n = 7), native artery occlusion (n = 3), or endograft migration (n = 1). A reduction in mean aneurysm sac diameters and volumes has been noted at every follow-up interval., Conclusion: Consistent with other reports, perioperative morbidity and mortality were significantly reduced in the endovascular group compared with the open repair group. Six-year follow-up of patients treated with the Powerlink system demonstrates the continued safety and efficacy of its treatment of abdominal aortic aneurysm.

Background: Suprarenal fixation is widely used in endovascular aneurysm repair. Numerous small, underpowered studies have concluded that it does not increase the risk of renal impairment compared with infrarenal fixation. A recent meta-analysis demonstrated that renal infarction is more common with suprarenal fixation, but the effect on renal function remains unclear., Methods: Electronic abstract databases, article reference lists, and conference proceedings were searched for series reporting renal function data after suprarenal fixation. There was considerable study heterogeneity with respect to key factors such as pre-existing renal dysfunction and length of follow-up. Authors were contacted to obtain individual patient data for a pooled reanalysis using standardized criteria., Results: Of 46 potentially relevant citations, only 11 were eligible for inclusion in the meta-analysis. Complete data sets were available for four studies (1065 patients), with a median follow-up of 33 months. Kaplan-Meier curves were constructed for postoperative renal impairment in the suprarenal fixation and infrarenal fixation groups and compared by the log-rank test. Median time free of renal impairment was 38.5 months in the infrarenal fixation group compared with 32.4 months in the suprarenal fixation group (P = .0038). However, to account for significant methodologic differences, further analysis was required using a Weibull regression model fitted in open Bayesian inference using Gibbs sampling (BUGS). The pooled hazard ratio for deterioration of renal function after suprarenal fixation was 0.6 (95% confidence interval, 0.3-10)., Conclusion: Currently available data are insufficient to determine the precise effect of suprarenal fixation on medium-term renal function. Conventional Kaplan-Meier analysis of the pooled data set suggested that suprarenal fixation increased the risk of renal dysfunction; however, the effect disappeared when sophisticated statistical modelling was performed to account for study heterogeneity. A randomised controlled trial of suprarenal fixation may resolve this issue.

Fistulae between the vasculature and the ureter are rare. We describe a communication between the ureter and the sac of an aortic aneurysm following abdominal aortic aneurysm repair.

Purpose: This study was performed to determine whether endoleaks could be detected after endovascular aneurysm repair (EVAR) with use of technetium-99m sulfur colloid and (99m)Tc-labeled red blood cell (RBC) nuclear medicine scans., Materials and Methods: There were 13 patients enrolled in this study: nine with endoleaks seen on computed tomographic (CT) angiography and four with no endoleak on CT angiography. All patients underwent regularly scheduled surveillance CT angiography examination after EVAR to evaluate for endoleak. Endoleak detection was then attempted in each patient with two nuclear medicine scans: a (99m)Tc sulfur colloid scan and a (99m)Tc-labeled RBC scan. Flow images (5 seconds per frame) were obtained for 1 minute after intravenous administration of 555 MBq (15 mCi) (99m)Tc sulfur colloid. Sequential dynamic images were then obtained every minute for 30 minutes. Next, a (99m)Tc-labeled RBC study was performed after the intravenous administration of 370-1,073 MBq (10-29 mCi) in vitro labeled (99m)Tc RBCs. Flow images were obtained, followed by sequential dynamic images obtained every minute for 30 minutes. Single photon emission CT images of the abdomen were then acquired. The nuclear medicine scans were evaluated for the presence or absence of endoleak independent of the CT angiography findings., Results: Of the nine patients with endoleaks on CT angiography, seven (78%) had them detected by nuclear medicine examinations. Two of the nine endoleaks seen on CT angiography (22%) were not seen on either scintigraphic examination. All patients with no endoleak on CT angiography had their nuclear medicine scans correctly interpreted as showing no endoleak present (n = 4; 100%). No complications occurred as a result of the nuclear medicine scans., Conclusions: Endoleaks can be detected with (99m)Tc sulfur colloid and (99m)Tc-labeled RBC nuclear medicine scans. This initial work suggests that the sensitivities of these scintigraphic scanning methods for endoleak detection are lower than that of CT angiography.

Objective: Endovascular aneurysm repair (EVAR) is rapidly becoming the predominant technique for repair of abdominal aortic aneurysms. Results from current studies, however, are conflicting on the effect of EVAR on renal function compared with standard open repair. Furthermore, data for open repair in patients with baseline renal insufficiency suggests worse outcomes, including renal function. This analysis compared the effects of open repair vs EVAR on renal function in patients with baseline renal insufficiency., Methods: We reviewed our records for patients with preoperative chronic renal insufficiency (serum creatinine, 1.5 mg/dL) who underwent open repair or EVAR between 1999 and 2004. The same group of vascular surgeons at a single institution performed aneurysm repair on 98 patients: 46 open (37 men, 9 women) and 52 EVAR (50 men, 2 women). Preoperative, postoperative, and follow-up serum creatinine and creatinine clearance were compared, as was the development of postoperative renal impairment (increase in serum creatinine >30%)., Results: Serum creatinine and creatinine clearance were not statistically different between the open and EVAR groups during any time period studied. Likewise when comparing the magnitude of change in serum creatinine in patients between the postoperative and follow-up times with preoperative values, no significant differences existed between the open and EVAR groups. When the change in serum creatinine over time within each group was compared, however, the open group had a significant increase in serum creatinine postoperatively (2.43 +/- 1.20 vs 2.04 +/- 0.64, P = .012), which returned to baseline during follow-up (1.96 +/- 0.94, P = .504). Although serum creatinine in the EVAR group increased compared with preoperative values of 2.04 +/- 0.55 (postoperative, 2.27 +/- 1.04; follow-up, 2.40 +/- 1.37), this failed to reach statistical significance for the postoperative (P = .092) or follow-up (P = .081) periods. A similar pattern was noted in creatinine clearance. Postoperative renal impairment was noted in 13 open (28%) and 15 EVAR patients (29%) and was not statistically different between groups. Overall, two patients (4.3%) from the open group and four (7.7%) from the EVAR group required hemodialysis; one in the EVAR group required permanent hemodialysis. This difference was not statistically significant (P = .681)., Conclusions: Open and endovascular repair of abdominal aortic aneurysms in patients with pre-existent renal insufficiency can be performed safely with preservation of renal function. In contrast to previous reports, no significant differences existed between open repair and EVAR in postoperative alterations in renal function. Although a significant increase in serum creatinine develops in patients with renal insufficiency postoperatively with open repair, this appears to be transient, and preoperative renal dysfunction alone should not exclude either approach. After EVAR, patients with pre-existing renal insufficiency continue to be at risk for progressive renal dysfunction, and protective measures should be taken to preserve renal function in this patient population.

The aim of the study was to review the results of abdominal aortic aneurysm (AAA) repair with the Powerlink Bifurcated endovascular graft, when compared with open AAA repair. A prospective, controlled, multicenter trial of the Powerlink System for endovascular abdominal repair (EVAR) was conducted at 15 sites as part of a pivotal FDA trial. Between July 2000 and March 2003, 258 patients were enrolled (192 test and 66 control patients). Stent grafts were oversized by 10-20% relative to computed tomography (CT)-based diameter measurements. All repairs were performed in the operating room through one surgically exposed femoral artery and a contralateral 9 French sheath percutaneously placed. Results were assessed using contrast-enhanced CT and plain abdominal X-rays at 1, 6, and 12 months and annually postoperatively. Mean follow-up of 36 months was available. Technical success was achieved in 97.9% of patients, with 4 failed insertions: 3 early conversions for deployment issues and one access failure. There was a significant difference in 30-day mortality between Powerlink (1%) and control (6.1%) patients and only 1 death was procedure-related (P=0.0389). Blood loss (341 mL vs 1 583 mL, P<0.0001), operative time (136 min vs 222 min, P<0.0001), Intensive Care Unit (ICU) stay (0.78 days vs 4.1 days, P<0.0001) and hospital length of stay (3.3 days vs 9.5 days, P<0.0001) were significantly less in the Powerlink cohort compared with controls. Secondary procedures have been performed on 16 patients post-implant to 48 months follow-up. At the time of the first month CT scan, endoleaks were noted in 25 patients, yielding a 30-day endoleak rate of 22.3%. Type II endoleaks predominated and there were no type III or IV endoleaks. The 4-year endoleak-free survival rate was 73%. No Type I, III or IV endoleaks were reported at 48 months post-implant. There have been no ruptures, graft fabric defects or wire fractures. Sac regression was noted in 83% of patients. Significant reduction in mean AAA diameter and volume was noted over every follow-up interval. In comparison to the 1-month post-implant CT scan, 2 patients had an increase in AAA diameter 5 mm at 48 months. The Powerlink system appears to be safe, and effectively protects patients from AAA rupture over the follow-up period. The graft and stent materials are still free from failure and fatigue. Contralateral limb access (9 Fr) facilitates graft placement in patients with disadvantaged access routes. EVAR performed with the Powerlink produces significantly less early adverse events than open AAA repair. Continued follow-up over the longer term is necessary to assure the durability of these results.

Despite improvements in endovascular aortic aneurysm repair (EVAR) devices and techniques, significant anatomic constraints still preclude successful EVAR in a large number of patients. The authors sought to identify the current barriers to EVAR and examine their evolution over time. Patients were evaluated for potential endovascular repair by computed tomography angiography (CTA) with or without supplemental conventional arteriograms. The patient population was separated into 2 groups (A and B) based on early and late time periods in the experience with EVAR, corresponding to the availability of various devices. Group A (early) consisted of the Guidant Ancure, Medtronic Talent, and AneuRx devices and comprised patients presenting between April 1997 through June 2000. Group B (late) consisted of the Medtronic AneuRx, Cook Zenith, Edwards Lifepath, Gore Excluder, and Endologix PowerLink devices and comprised patients presenting between July 2000 and December 2003. Patient demographics and anatomic reasons for rejection were recorded in a database for statistical analysis. In total, 547 patients were evaluated (463 men, 84 women). Of these, 346 patients (63%; 312 men, 34 women) were deemed suitable candidates for EVAR and 201 (37%; 151 men, 50 women) were rejected. There was no significant difference in the overall rate of rejection in the early vs the late time period (34% A, 41% B, p = 0.08), but the number of exclusion criteria per patient decreased over time; patients rejected for EVAR had an overall average of 1.6 exclusion criteria (Group A, 1.9; Group B, 1.2). The reasons for rejection did significantly change over time. Specifically, rejection on the basis of inadequate arterial access, presence of extensive iliac artery aneurysms, or an inadequate proximal neck decreased. A disproportionate number of women were excluded throughout the study: Group A, 56% of women compared to 30% of men (p = 0.0003); Group B, 63% of women compared to 36% of men (p = 0.0022). Women were more likely than men to have inadequate arterial access routes. In addition, patients with high operative risk were also more likely to be excluded from EVAR, a finding that persisted over time. Anatomic constraints continue to pose significant challenges to aortic endografting. Progress has been made in that technological advances have conquered some of the previous anatomic challenges, chiefly those of arterial access and treatment of concomitant iliac aneurysm disease. However, the overall rate of rejection for EVAR remains the same. The chief anatomic barriers continue to be the difficult aortic neck and management of branched vascular segments.

Objectives: Although suprarenal fixation may be of benefit during endovascular aneurysm repair (EVAR), its safety with regards to renal effects remains uncertain. To date, there has been no controlled study of the topic, with most reports relying upon single-center experiences that use heterogeneous patient populations and devices from different manufacturers. The purpose of this analysis was to evaluate the effect of suprarenal fixation on renal function by comparing homogeneous patient populations receiving EVAR grafts from a single manufacturer that are identical in design and delivery method, except for utilizing either suprarenal (SR) or infrarenal (IR) fixation., Methods: During two pivotal US Food and Drug Administration trials, 283 patients underwent EVAR with the Powerlink bifurcated graft. The trials' inclusion and exclusion criteria and grafts were identical except for fixation scheme. Clinical, laboratory, and computed tomographic (CT) data were retrospectively reviewed. A comparison of preoperative, perioperative (1 to 7 days), and postoperative (>7 days) alterations in serum creatinine (SCr), creatinine clearance (CrCl), and blood pressure was performed. Renal adverse events were determined by CT scan and clinical chart review and included renal infarction, renal artery stenosis (either progressive or requiring renal stent placement), and renal artery occlusion., Results: Both SR and IR groups demonstrated a significant increase in SCr and a decrease in CrCl over time. No significant difference in SCr or CrCl existed between groups during any time period. There were no differences in postoperative renal impairment (IR, 10.2%; SR, 7.6%, P = .634), the need for hemodialysis (IR, 0.7%; SR, 0%, P = 1.00), or systolic and diastolic blood pressure during subsequent follow-up between treatment groups. There was no significant difference in the number of renal adverse events detected by CT between the IR (10, 6.8%) and SR (3, 3.8%) groups (P = .550)., Conclusion: Suprarenal fixation does not lead to a significant increase in acute renal events, renal impairment, or alteration in blood pressure compared with infrarenal fixation. Patients undergoing aneurysm repair with devices that use either suprarenal or infrarenal fixation develop progressive renal dysfunction over time. Further studies are needed to determine the long-term effects of suprarenal fixation on renal function and progression of renal artery stenosis.

Objective: Accessory renal arteries are frequently encountered when patients are evaluated for endovascular abdominal aortic aneurysm repair (EVAR). Some have considered their presence a contraindication to EVAR in fear of endoleak and the end result of renal function. We sought to determine whether the coverage of accessory renal arteries during EVAR was associated with any adverse sequelae., Methods: Retrospective review of the medical records and computed tomographic scans of all patients undergoing EVAR (1998 to 2003) was performed. Note was made of the presence or absence of accessory renal arteries, hypertension, and renal function. Preoperative computed tomographic images were compared with postoperative images to determine the presence of renal infarction. A control group of 26 consecutive patients without accessory renal arteries was used for comparison of the results of EVAR., Results: EVAR was performed in 550 patients over the study interval. The mean follow-up was 16 months (range, 1-48 months). The average age was 74 years (range, 57-90 years). Thirty-five patients (6.6%; 32 male and 3 female) were documented to have accessory renal arteries; the average number of accessory arteries was 2 (range, 1-4). Bilateral accessory arteries were present in 13 patients: all but 1 patient (n = 34) had a left-sided accessory renal artery, and 23 had a right-sided accessory renal artery. EVAR was performed with a variety of endografts: AneuRx (n = 10), Talent (n = 7), PowerLink (n = 7), Zenith (n = 5), LifePath (n = 4), and Ancure (n = 2). There were no mortalities. Twelve endoleaks were documented: three type I, eight type II, and one type III. The accessory renal arteries were not implicated in any of the endoleaks, and none of these accessory vessels was embolized before or after EVAR. Seven patients (20%) had renal infarcts associated with EVAR that were noted on follow-up computed tomographic scans. The mean follow-up for patients with segmental infarction was 23 months (range, 8-48 months). Hypertensive status did not change in any patient in whom an accessory renal artery had been covered. The average serum creatinine was 1.08 mg/dL (range, 0.6-1.8 mg/dL) before EVAR in patients with accessory renal arteries covered by an endovascular graft and did not change significantly in response to EVAR. Serum creatinine increased almost twofold in two patients but spontaneously resolved in follow-up. The average preoperative creatinine clearance was 79 mL/min (range, 35-166 mL/min) in patients without an accessory renal artery and was 80 mL/min (range, 35-167 mL/min) after EVAR. The average preoperative creatinine clearance was 67 mL/min (range, 31-137 mL/min) in patients with an accessory renal artery and 68 mL/min (range, 45-83 mL/min) in patients with renal infarcts. None of the patients required temporary or permanent dialysis. There was no difference between control patients and patients with covered accessory renal arteries with respect to hypertensive status, presence of renal infarcts, serum creatinine, or creatinine clearance after EVAR., Conclusions: Occlusion of accessory renal arteries is not associated with clinically significant signs or symptoms, even in patients with mild or moderate renal insufficiency. Sacrifice of accessory renal arteries most commonly does not lead to detectable renal infarction, either clinically or radiographically. When segmental infarction of the kidney does result, it seems to be well tolerated in this group of patients. Accessory renal arteries were not found to contribute to endoleaks and should not be prophylactically embolized.

Purpose: The optimal modality for following aneurysm size and detecting endoleaks after endovascular aneurysm repair (EVAR) remains controversial. Computed tomographic angiography (CTA) has been widely employed but can be limited by metal artifact from stents, which is exacerbated by embolization coils placed during the treatment of type 2 endoleaks. The authors assessed interobserver agreement of CTA for measuring aneurysm size and presence of recurrent endoleak in patients with prior coil embolization of type 2 endoleaks., Materials and Methods: A total of 65 CTAs were retrospectively reviewed in a cohort of 27 patients (25 men; two women; mean age, 77.4 years) who had prior endoleak embolization after EVAR. Endoleak embolizations included transarterial (n=8) and translumbar (n=19) approaches. In each patient, maximal aneurysm diameter and presence/absence of recurrent endoleak was measured independently by two observers. Cohen's Kappa statistic was used to assess interobserver agreement, as well as paired two-tailed Student t tests for aneurysm diameter., Results: Recurrent type 2 endoleaks were detected with CTA in eight of 27 patients (30%) and on 13 of 65 CTAs (20%). A high degree of correlation (98.5%) was also seen between the two observers for presence of endoleak (Kappa=0.95). Mean aneurysm diameter for the entire cohort correlated closely between both observers: 54.8 mm+/-1.1 for observer A and 54.9 mm+/-1.1 for observer B (P=.66). There was a disagreement between the readers of greater than 2 mm regarding aneurysm size in 13.8% of the CTAs (nine of 65 CTAs)., Conclusion: Despite the presence of streak artifact on CTA following coil embolization of type 2 endoleaks, CTA remains a useful study for following patients. The presence of embolization coils does not prevent CTA measurement of aneurysm diameter and detection of recurrent endoleak with a high degree of interobserver agreement.

Translumbar embolization was used to treat 11 type 2 endoleaks in nine patients with the liquid embolic agent n-butyl cyanoacrylate (NBCA). Nine of the embolizations were performed with a combination of stainless-steel coils and NBCAJ and the other two were performed with NBCA alone. There was complete occlusion on initial computed tomographic (CT) angiography in six of nine patients (66%), including the two cases treated with NBCA alone. Persistent endoleak on initial CT angiography occurred in three of nine patients (33%). Two of these patients underwent successful repeated embolization with NBCA. Aneurysm size remained unchanged in four patients (44%), decreased in four patients (44%), and increased in one patient (11%). No complications occurred. Initial results with the use of NBCA for endoleak embolization are encouraging.

Purpose: Accurate endoleak detection and classification is critical for the follow-up of patients who have undergone endovascular aneurysm repair (EVAR). This determination is often made with computed tomography angiography (CTA). This investigation was performed to determine the accuracy of CTA in the classification of endoleaks in patients who have undergone EVAR., Materials and Methods: Thirty-six patients with endoleaks underwent both CTA and conventional contrast digital subtraction angiography (DSA) to determine endoleak etiology. Two independent radiologists determined the source of the endoleak based on a retrospective review of the CTA. The results of the CTA-based endoleak classification were compared to the reference standard, contrast DSA., Results: There was agreement regarding endoleak classification between CTA and DSA on 86% of the patients (31 of 36 patients). Correlation between the CTA reading of the two readers was 94% (34 of 36 patients), yielding a kappa statistic of 0.8. In three patients, the CTA reading incorrectly classified endoleaks as type 2 when the endoleaks were actually type 1 endoleaks on DSA. One patient was incorrectly classified as having a type 1 endoleak on CTA when it was a type 2 endoleak on DSA. Finally, one patient had a type 1 endoleak on DSA that was incorrectly classified as a type 3 endoleak on CTA. The change in CTA endoleak classification based on the DSA resulted in a significant change in patient management in four of the 36 patients (11%)., Conclusions: Endoleak classification based on CTA correlates fairly well with DSA findings. However, optimal endoleak management requires performance of selective angiograms with DSA to classify endoleaks that are detected on CTA.

Background: Endovascular aneurysm repair (EVAR) (using an Federal Drug Association-approved AneuRx device) compared to conventional surgical repair of abdominal aortic aneurysm (AAA) previously rendered favourable outcomes regarding post-operative pain, avoidance of laparotomy, and rapid rehabilitation and hospital discharge in high-risk patients, including octagenarians., Objectives: To assess the safety, reduction in aneurysm-related deaths, and interim survival data up to 72 months after AAA exclusion by endoluminal endografts (EVAR)., Design: We carried out an open, controlled, prospective, multidisciplinary EVAR study for the period 1998 to 2003 (six years). In the earlier part of the study, EVAR was compared with previously published results of conventional open aneurysmectomy surgery., Setting: Heart Unit, Panorama Medi-Clinic, Parow, South Africa., Participants: We recruited adult male and female patients presenting with AAA and fulfilling the inclusion criteria for endovascular repair, as recommended by the consensus 2003 meeting of the Vascular Association of South Africa (VASSA). All patients were offered open surgery as an alternative and were entered into the VASSA EVAR trial registry. Pre-operatively, AAA anatomy was assessed by spiral-computed tomography (CT), and selectively with conventional angiography and intravascular ultrasound (IVUS). Informed consent was obtained in accordance with the recommendations of the Senate of Surgery Paper 2, Ethical Guidelines, Great Britain and Ireland. Patients underwent EVAR by a multidisciplinary interventional team., Interventions: Two hundred and seven adult patients with AAA were assessed. Forty-four of the 207 (21.2%) were excluded from EVAR because of irreversible comorbid factors and complex aneurysm morphology. One hundred and sixty-three patients (78%), with a mean age of 70.7 years (range 60-91 years), underwent EVAR (1998-2003). Five patients were lost to follow-up (3%). Median AAA diameter was 56.9 mm and ASA ratings were I, 1.2%; II, 15.9%; III, 57%; IV, 22.6%; and V, 2.4%. EVAR was performed in high- and low-risk categories of both sexes. Most patients were in ASA groups III and IV. DEVICES DEPLOYED: EVAR was performed using a selection of endografts over 72 months- AneuRx (Medtronic) 47; Talent (Medtronic) 49; Vanguard three; Zenith (Cook) one; Powerlink (Endologix) 62; and other, one., Results: Thirty-day outcome: successful deployment 99%, primary stent patency 97%, surgical conversion 0.6%, procedural or intra-operative mortality 1.2%, 30-day mortality 4.3%, endoleaks 1.84%, and secondary intraprocedural endovascular interventions 24.5%. Perioperative mortality was 3.1% (one aneurysm related). One patient had suspected endograft infection. Late mortality was 21.4% (35 patients due to co-morbidities, and one was aneurysm related). Follow-up was a median of 28.3 months (range 1-69 months). In 163 patients, two persisting endoleaks (1.2%) were detected. Endotension was detected in 3/163 (1.8%) with average sac increase of 0.8 cm. Conversion to open surgery was needed in one patient (0.6%). Co-morbidities that contributed to late mortality included multi-organ failure, ischaemic heart disease (IHD), cardiomyopathy, renal failure, stroke and cancer. One procedural rupture was fatal (0.6%). Two late ruptures occurred; one was successfully endostented and the other patient died after a failed surgical intervention (0.6%). Endovascular repair of AAA is more expensive than conventional surgery. Introduction of the Endologix stent has reduced operative time from 120 to 60 minutes in un complicated patients. Newer-generation aortic stents allow better control of negative remodeling and stent migration., Conclusion: A multidisciplinary team can safely perform EVAR, with a low 30-day mortality rate in selected patients graded ASA II-IV and with favourable aortic aneurysm morphology. About 22% of patients with AAA are not suited for EVAR. Persisting late endoleaks occurred in 1.2% of the cohort study and were not device specific. Life-long follow-up post EVAR is a prerequisite to detect late device failure, endoleaks and aneurysm-sac enlargement, and to assure the durability of these midterm results. Short-term aneurysm rupture prevention is a predictable outcome in high-risk groups.

Objective: This study was undertaken to determine whether a complicated aortic neck is associated with unfavorable outcome after abdominal aortic aneurysm (AAA) endografting., Methods: In a prospective pivotal clinical trial, 237 consecutive patients underwent implantation of the bifurcated Talent Low Profile System. Patients were divided into 2 groups, those with complicated aortic necks (short, <15 mm; very short, < or =10 mm; dilated, >28 mm; angulated, >45 degrees; calcified; and thrombus-lined) versus those with uncomplicated neck anatomy. Major outcome parameters included procedure time, operative blood loss, transfusion requirements, volume of contrast medium used during the implant procedure, endoleaks, migration, limb patency, AAA regression, conversion to open repair, morbidity, and mortality. Mean follow-up was 620.5 days., Results: Overall, 32% of aortic necks were short, 19% were very short, 20% were dilated, 18% were calcified, 8.5% were thrombus-lined, and 19.9% were angulated. Thirty percent and 70% of patients, respectively, were stratified to the uncomplicated and complicated groups ( P < .01. Procedure time, operative blood loss, transfusions, volume of contrast medium used in the implant procedure, migration, endograft patency, AAA sac regression, conversion to open repair, and mortality were not significantly different in necks with complicated versus uncomplicated anatomy. At 21 months, sacs were regressing or stable in 98% (complicated) versus 96% (uncomplicated). Primary graft limb patency was 100% in both groups. The endoleak rate was 4.3% (complicated) versus 17% (uncomplicated) at 18 months, but this difference was not statistically significant. Adverse renal events, however, occurred in 27.5% (complicated) versus 13.6% (uncomplicated; P = .04)., Conclusions: Complicated aortic neck is not associated with unfavorable outcome at midterm follow-up after AAA endografting. However, statistically more adverse renal events occur in patients with complicated neck anatomy.

Purpose: We assessed the results of abdominal aortic aneurysm (AAA) repair with the Powerlink bifurcated endovascular graft compared with open AAA repair., Method: A prospective controlled multicenter trial of the Powerlink system for endovascular aneurysm repair was conducted at 15 sites as part of a pivotal US Food and Drug Administration trial. Between July 2000 and March 2003, 258 patients (192 test patients, 66 control patients) were enrolled. Stent grafts were oversized by 10% to 20% relative to computed tomography scan (CT)-based diameter measurements. All repairs were performed in the operating room through 1 surgically exposed femoral artery and a contralateral 9F sheath percutaneously placed. Results were assessed with contrast material-enhanced CT scans and plain abdominal x-ray studies at 1, 6, and 12 months, and annually postoperatively., Results: Patients were followed up for a mean of 22 months (median, 24 months). Technical success was achieved in 97.9% of patients, with 4 failed insertions (3 early conversions because of deployment issues, 1 access failure). There were no significant differences in mortality between the Powerlink and control groups, and only 1 death was procedure-related. Blood loss (341 mL vs 1583 mL; P < .0001), operative time (136 minutes vs 222 minutes; P < .0001), intensive care unit stay (0.78 days vs 4.1 days; P < .0001), and hospital length of stay (3.3 days vs 9.5 days; P < .0001) were significantly less in the Powerlink cohort compared with the control group. There were significantly fewer adverse events (myocardial infarction, P = .0131; renal failure, P = .0042; gastrointestinal complications, P = .0125) in the perioperative period in the Powerlink cohort compared with the control group, but in the longer follow-up interval adverse event-free survival was equivalent between groups (P = .456, log-rank test). At the time of the first-month CT scan, endoleaks were noted in 25 patients, yielding a 30-day endoleak rate of 22.7%. Type II endoleaks predominated, and there were no type III or IV endoleaks. Secondary procedures were performed in 19 patients (10%), for treatment of endoleak (n = 10), limb obstruction (n = 7), and other causes (n = 2). There were 3 graft migrations (2.2%), 1 of which resulted in an endoleak. There were no ruptures, graft fabric defects, or wire fractures. Significant reduction in mean AAA diameter and volume was noted at every follow-up interval. Increase in AAA diameter was noted in only 1.5% of patients at 24 months., Conclusion: The Powerlink system appears safe, and effectively protects patients from AAA rupture over the intermediate term. The graft and stent materials have thus far been free from failure and fatigue. Percutaneous contralateral limb access facilitates graft placement in patients with disadvantaged access routes. Endovascular aneurysm repair with the Powerlink system produces significantly fewer early adverse events compared with open AAA repair, but mortality is equivalent with both procedures. Careful follow-up over the longer term is necessary to ensure the durability of these results.

Objective: The purpose of this study was to determine the impact of using computerized software-assisted centerline measurements for extensions and graft junctions during the selection of endograft components for modular aortic endografts in endovascular repair of abdominal aortic aneurysms., Methods: From April 1998 to December 2002, 289 modular aortic endografts were implanted at our institution. These included 248 grafts (prior to 2002, group 1) with components selected on the basis of manual caliper measurements from combined contrast computed tomography (CT) and marker-catheter arteriography data, and 41 grafts (2002, group 2) with components selected with the use of computerized software that allowed for centerline measurements on 3-dimensional reconstructions based on CT data. These 2 groups were compared for the number and type of extensions required per case. Seventeen other relevant variables were analyzed for their potential influence on selection of endograft components. These variables included age, gender, maximum aneurysm size, level of distal fixation, length and diameter at the fixation points, endograft manufacturer (make), and configuration. The significance of the observed differences was analyzed with a multivariate regression model, adjusting for potentially confounding preoperative measures., Results: Multivariate analysis demonstrated that the number of right iliac extensions, left iliac extensions, total extensions, and total graft junctions was significantly reduced by the use of computerized software-assisted centerline measurements (group 2) compared with caliper measurements (group 1), independent of all other 17 preoperative variables. Notably, the mean number of required right iliac extensions was double in group 1 versus group 2., Conclusions: Centerline software-assisted measurements can significantly reduce the need for iliac extensions and, concomitantly, the number of required endograft junctions. On average, twice as many extensions were required for right iliac fixation when the manual caliper measurements were used compared with software-assisted measurements. These findings are highly relevant to issues of total endograft cost and long-term endograft integrity and focus attention on the tools that may need to be considered standards of care rather than optional for selection of endograft components.

Purpose: Food and Drug Administration-approved endografts are suitable for the elective repair of abdominal aortic aneurysms (AAAs) with favorable aneurysm anatomy. Our aim is to illustrate the feasibility and versatility of commercially available endografts for emergency AAA repair in hemodynamically stable AAA rupture., Methods: From June 2001 to July 2002, five patients presented with severe abdominal pain and were diagnosed with contained rupture of an infrarenal AAA. In all cases, patients were deemed unfit to withstand conventional open repair by both the referring outside medical center as well as our center's team. All patients were hemodynamically stable on arrival at our medical center. Measurement and selection of endovascular devices were based on computed tomography (CT) scans performed emergently at the outside referring center. The required emergently procured endografts were obtained within 2 to 4.5 hours (mean, 3.1 hours) of presentation. Complex anatomy at the proximal and distal fixation zones or difficult access was present in every case., Results: All patients survived endograft repair and had successful exclusion of their aneurysm sac on the basis of intraoperative arteriography and postoperative CT surveillance. All were discharged to home at baseline function within a mean of 6.8 days (range, 2-13 days). There were no deaths. There was one postoperative pulmonary embolism, one myocardial infarct, and one type 2 endoleak. Mean operative time and blood loss were 4.67 hours and 217 mL, respectively. At a mean follow-up of 18 months, CT scans showed stable or shrinking aneurysm sacs., Conclusions: In patients with contained ruptured AAAs who present with hemodynamic stability and comorbidities that preclude open surgery, commercially available endografts are a versatile treatment option even in the face of complicated aneurysm anatomy.

Purpose: This study was undertaken to assess the results of endovascular aortic aneurysm repair with the Lifepath abdominal aortic aneurysm (AAA) graft system., Method: In a prospective clinical trial, 23 centers used the Lifepath System balloon-expandable, modular bifurcated stent graft for elective endovascular aortic aneurysm repair. Stent grafts were sized according to computed tomographic angiography-based diameter measurements. All repairs were performed in the operating room through bilateral surgically exposed femoral arteries. Results were assessed with contrast agent-enhanced computed tomography scans and plain abdominal x-ray films at 1, 6, 12, 24, 36, and 48 months postoperatively., Results: Over 52 months (mean follow-up, 11 months), 227 patients (206 men, 21 women) were enrolled. Technical implant success rate was 98.7%. There were five (2.2%) conversions to open surgery: two emergently because of aortic perforation; to treat refractory endoleak, immediate in one and at 12 months in one; and to replace a device with wireform fractures that had migrated at 12 months, resulting in a proximal endoleak. The perioperative mortality rate was 1.3%. There was one operative death during a secondary procedure to repair perforation of the aorta. There were two perioperative deaths, from postoperative myocardial infarction (n = 1) and pulmonary embolus (n = 1). There were 12 late deaths, from coronary artery disease (n = 4), cancer (n = 2), respiratory failure (n = 2), sepsis (n = 1), or unknown cause (n = 3). Median length of stay was 2 days (mean, 4 days). There have been no AAA ruptures after successful implantation of the device, no graft limb thromboses, and no limb dislocations. At the time of operation endoleak was noted in 43 (19%) patients, but by 6 months this was reduced to 8 (5.9%) patients (type I, n = 1; type II, n = 7). There were no type III or type IV endoleaks. Secondary interventions to treat endoleaks included open conversion (n = 2), placement of extension cuffs (n = 4), repeated balloon dilation (n = 3), and coil embolization (n = 6). The two remaining secondary interventions were emergent treatment of postoperative bleeding from a groin incision, and a colon resection because of postoperative colonic ischemia, for a 12-month secondary intervention rate of 7.5%. Wireform fractures were noted in the first generation Lifepath device in 37 of 79 (47%) patients. Graft migration (>10 mm) was observed in five patients (2.2%), each of whom also had two or more fractures of the proximal anchoring wireforms. Migration resulted in a proximal attachment endoleak in one patient. In response to wireform fractures, the device was modified after the initial 79 patients were enrolled. Wireform fracture has been observed in six patients since this modification (4%), and in only one patient did this involve fracture of a proximal anchoring wireform; none of these patients has had endoleak or graft migration. By 12 months, mean aneurysm diameter was noted to decrease by 9 mm (P <.0001), and mean aneurysm volume by 42 mL (P <.0001) from the preoperative visit., Conclusion: The Lifepath System demonstrates a low endoleak and secondary intervention rate and high sac regression rate, compared with other devices. The unique balloon-expandable design offers the advantages of precise placement and high radial force. The device appears to be highly resistant to limb thrombosis and modular component separation. Patients were protected from AAA rupture after successful device implantation, and demonstrated significant reduction in AAA diameter and volume. Fractures of the wireforms of the main body of the device have been observed. Careful long-term follow-up is necessary.

Purpose: The purpose of this study was to determine whether the morbidity and mortality of surgery for thoracoabdominal aortic aneurysm (TAAA) in patients with prior aortic surgery are increased., Methods: The results for all patients undergoing operation for TAAA at a single institution were reviewed., Results: Over a 10-year interval, 279 patients (136 women and 143 men) underwent aortic replacement for TAAA. The mean patient age was 68 years (range, 34-90). The extent of aortic replacement was relatively evenly distributed: type I (91), type II (54), type III (78), or type IV (56). Of these 279 patients, 76 (27%) had undergone prior aortic surgery. Prior infrarenal AAA was the most common prior procedure (56, 20%). Reoperation for prior failed TAAA repair was performed in 20 (7%) patients. A history of Marfan syndrome was highly associated with the need for remedial TAAA procedures (P <.0001). Overall 30-day mortality was 11.4% (32). Mortality was independent of prior aortic surgery (P =.98), prior AAA (P =.84), prior TAAA (P =.61), and gender (P =.18). Postoperative complications were seen in 67 (24%) patients and were more likely in patients who had undergone prior AAA surgery (P =.008). TAAA repair in patients with recurrent TAAA was not associated with higher morbidity (P =.33). Paraplegia (10) occurred in type I (3), type II (2), and type III (5) aneurysms but not in type IV (0), and its development was associated with higher mortality (P =.01). Prior aortic surgery was not found to be predictive of paraplegia (P =.90), although 30% of patients who developed paraplegia had a history of prior AAA repair., Conclusions: Aortic reoperation for TAAA is required in a significant number of patients, particularly those with Marfan syndrome. Therefore, ongoing surveillance of the residual aorta is mandatory. Postoperative complications are more likely to occur in patients after prior infrarenal aortic replacement, but mortality is not significantly increased. Special technical considerations exist for remedial procedures after failed TAAA repair to provide protection for the spinal cord, kidneys, and viscera. Patients with failed TAAA procedures or progression of aneurysmal extent should be offered reoperation when indicated.

Endovascular repair of abdominal aortic aneurysms shows promising initial results. Endoleaks represent one of the unique causes of endovascular repair failure not seen with traditional abdominal aortic aneurysm repair. Endoleaks occur when there is blood flow outside the stent-graft lumen but within the aneurysm sac. They can be difficult to diagnose and treat, and their management is a source of continued controversy. This review further defines endoleaks and the clinical challenges that they create. Current methods for endoleak detection, classification, and management are reviewed.

When embolization of a collateral (type II) endoleak after endovascular repair of an abdominal aortic aneurysm is indicated, endoleak embolization with a translumbar approach is often the procedure of choice. Because of the position of the endoleak, it is sometimes necessary to use a right-sided translumbar approach and traverse the inferior vena cava when accessing the endoleak. Twelve type II endoleaks in nine patients were treated with transcaval translumbar embolization during a 34-month period. No clinically significant hemorrhage occurred. Embolizing type II endoleaks with a right translumbar approach is feasible. Long-term follow-up with more patients is necessary to fully evaluate the durability of this procedure.

Purpose: Endovascular repair of abdominal aortic aneurysm (AAA) is expected to alter the natural progression of diameter increase and rupture. The purpose of this study is to determine the rate of diameter change in AAA treated by endovascular repair., Materials and Methods: Sixty-three patients underwent endovascular repair of AAA and 12-month median follow-up by computed tomographic (CT) angiography or magnetic resonance (MR) angiography. The maximum cross-sectional outer diameters of aneurysms were measured with serial CT angiography and MR angiography. Immediate postrepair CT angiography and MR angiography were used for comparison to follow-up studies. Endoleak was also evaluated., Results: The mean and median follow-up interval was 12 months (range, 7-21 mo). There was a significant decrease in maximum diameter at follow-up (6.0 cm vs 5.1 cm; P <.001). The mean annual decrease of AAA diameter was 8.4 mm. Endoleak occurred immediately after repair in 12 patients (19%). Endoleak was detected in four patients at follow-up examination (6%). Two patients with persistent endoleaks had a mean diameter increase of 2.1 mm per year. Ten patients (16%) with successfully treated endoleak had a mean decrease in diameter of 11 mm per year. There is a significant difference in mean annual diameter change between patients with treated endoleak and those with persistent endoleak (P <.05). There was no difference in mean annual rate of change between patients with no endoleak and those with treated endoleak (8.4 mm/y vs 11 mm/y; P = NS). Seventeen of 21 patients without an appreciable decrease in aneurysm diameter had no endoleak., Conclusions: Patients with resolved endoleak exhibit a similar shrinkage rate to patients who never had endoleak during imaging follow-up. There remains a group of patients without significant sac shrinkage after endovascular aneurysm repair (EVAR) yet have no endoleak on follow-up imaging (ie, endotension). It is still unclear whether these patients have received protection from AAA rupture from EVAR.

Purpose: The purpose of this study was to assess the results of abdominal aortic aneurysm repair with the PowerLink bifurcated endovascular graft (Endologix, Inc, Irvine, Calif)., Method: Twelve centers used the PowerLink bifurcated system for elective endovascular aneurysm repair in 118 patients recruited during a 16-month interval and followed for a 25-month interval (mean follow-up, 16 months) as part of a pivotal US Food and Drug Administration trial. Stent grafts were oversized by 10% to 20% relative to computed tomographic scan-based diameter measurements. All repairs were performed in the operating room through one surgically exposed femoral artery and a contralateral 9F sheath percutaneously placed. Results were assessed with contrast-enhanced computed tomography and plain abdominal radiography at 1, 6, and 12 months after surgery., Results: Three failed insertions and one late conversion for endoleak remediation occurred, resulting in four conversions (3.3%) to open surgery. Of the failed insertions, two were from a faulty delivery system design, which was corrected. No failures occurred after the modification. One perioperative death (0.8%) occurred that was not device related. Eight late deaths were from unrelated causes, and one was from complications after reoperation for treatment of an endoleak. Endoleaks were noted in 19 patients (16%) at the time of the endograft procedure: 12 resolved spontaneously, four resolved with secondary interventions (three type I, one type II), and three underwent observation, yielding a 30-day endoleak rate of 5.9%. Two graft limb thromboses (0.8%) were seen. One graft migration (0.8%) was of no clinical significance. No ruptures or wire fractures were found. The mean aneurysm diameter was reduced from 51 mm (preoperative) to 45 mm (12 months; P <.0001)., Conclusion: The PowerLink system appears to be safe and effectively protects patients from abdominal aortic aneurysm rupture over the short to medium term. The low endoleak rate is superior to that reported for other devices. The graft and stent materials have thus far been free from failure and fatigue. The sutureless stent and endoskeleton design confer a number of unique advantages and challenges. Careful follow-up over the longer term is necessary to assure the durability of these results.

Objective: Successful endovascular aortic aneurysm repair depends on exclusion and spontaneous thrombosis of the aneurysm sac. The need for chronic postoperative anticoagulation therapy could limit the applicability of this technology with delay or prevention of sac thrombosis resulting in endoleak formation and altered remodeling of the aneurysm sac. The purpose of this study was the determination of whether chronic therapeutic anticoagulation therapy with warfarin was associated with an increased incidence rate of early or delayed postoperative endoleaks or altered rates of reduction in aneurysm sac maximum diameter., Methods: Two hundred thirty-two consecutive patients underwent abdominal aortic endografting during a 32-month period. The data were recorded prospectively with a current mean follow-up period of 18 months. The patients with endoleaks identified with 30-day postoperative computed tomographic scan angiograms subsequently underwent selective arteriography to characterize the source. The patients who underwent chronic warfarin therapy that resulted in a therapeutic internationalized normalized ratio comprised the study group. The control group was defined as all the patients with healthy coagulation profiles., Results: Thirty-six patients (15%) were undergoing warfarin therapy after surgery, and their conditions were chronically maintained with a therapeutic international normalized ratio. Forty-three patients (18%) had endoleaks on 30-day computed tomographic scan angiographic results. There were 39 patients with type II endoleaks and four patients with type I endoleaks. None of the type I endoleaks occurred in patients who were undergoing warfarin therapy, and all endoleaks were repaired with either proximal or distal covered extensions. At 30 days, seven patients (19.4%) undergoing chronic warfarin therapy had type II endoleaks as compared with 36 controls (18.4%; P =.798). Four patients had delayed type II endoleaks develop, two in the control group and two in the warfarin group (P =.3). Ten control individuals (31%) had spontaneous resolution of type II endoleaks develop, whereas spontaneous endoleak thrombosis was not observed in the warfarin group (P =.33). Aneurysm sac remodeling assessed with mean percent reduction in maximum sac diameter at 12 months revealed a statistical difference between the control group (17.5%) and the warfarin group (7.6%; P =.04)., Conclusion: Warfarin treatment is not associated with an increase in the incidence rate of early or delayed postoperative endoleaks. However, the rate of reduction in maximum aneurysm sac diameter after aortic endografting is slower in patients who undergo therapeutic warfarin therapy at 1-year follow-up examination, a statistically significant difference from the control group. In addition, type II endoleaks may be less likely to undergo spontaneous thrombosis in patients who undergo warfarin therapy.

Purpose: Endovascular abdominal aortic aneurysm (AAA) repair is reported to result in less initial patient morbidity and a shorter hospital length of stay (LOS) when compared with conventional AAA repair. We sought to examine the durability of this result during the intermediate follow-up interval., Methods: The records of all admissions for all patients who underwent AAA repair during a 26-month interval were reviewed., Results: Three hundred thirty-seven (337) patients underwent procedures to repair AAAs (163 open and 174 endovascular). Endovascular procedures were performed with a variety of devices (Talent, 108; Ancure, 36; AneuRx, 26; Zenith, 2; and Cordis, 2) and configurations (141 bifurcated and 33 aortomonoiliac). The mean follow-up period was 10.6 months (endovascular repair) and 12.3 months (open repair). LOS did not significantly vary by device (P =.24 to P =.92) or configuration (P =.24). The initial median LOS for procedures was significantly shorter (P =.009) for endovascular repairs (5 days) than for open procedures (8 days). However, the patients who underwent endovascular repair were more likely to be readmitted during the follow-up interval when compared with patients who underwent open procedure. The readmission-free survival rate after AAA repair at 12 months was 95% for patients for open AAA repair versus 71% for patients for endovascular repair (P <.001). If the total hospital days were compared, including the initial and all subsequent AAA-related admissions, there was no significant difference for mean LOS for patients who underwent endovascular versus open AAA procedures (11 days versus 13.6 days; P =.21). The patients for endovascular AAA repair most commonly needed readmission for treatment of endoleak (n = 31), wound infection (n = 12), and graft limb thrombosis (n = 9). Although women had similar LOS to men for endovascular repair (P =.44), they had longer initial LOS for open AAA repair (15 versus 10 days; P =.03). After endovascular repair, women were more likely than men to be readmitted by 12 months (51% versus 71% readmission-free survival rate; P =.03) and they had longer LOS on readmission (13.2 versus 5.2 days; P =.006). No gender differences were identified for patients after open AAA repair regarding readmission-free survival rate (P =.09) or LOS on readmission (P =.98)., Conclusion: Although initial LOS was shorter for the patients who underwent endovascular as compared with conventional AAA repair, this advantage was lost during the follow-up interval because of frequent readmission for the treatment of procedure-related complications, chiefly endoleak. These readmissions frequently involved the performance of additional invasive procedures. Gender differences existed regarding LOS and the likelihood of complications after open and endovascular AAA repair.

Aortocaval fistula (ACF) is a rare but life-threatening condition. This case report describes the use of bolus-chase gadolinium-enhanced 3D magnetic resonance angiography (MRA) to provide an efficient evaluation of a patient with ACF associated with a mycotic abdominal aortic aneurysm. This case highlights the ability of bolus-chase MRA to provide both the specific diagnosis of ACF as well as the information necessary for extra-anatomic arterial bypass. Bolus-chase MRA is a promising method for the evaluation of patients with this disease entity., (Copyright 2002 Wiley-Liss, Inc.)

Objective: The exact significance of collateral endoleaks is unknown and a topic of great debate. Because of this uncertainty, some physicians choose to watch and wait while others aggressively treat these leaks. The purpose of this investigation was the evaluation of the efficacy of the two techniques used in the treatment of collateral endoleaks that occur after endovascular aneurysm repair., Methods: Patients with 33 angiographically proven type 2 endoleaks underwent treatment with either transarterial inferior mesenteric artery embolization (n = 20) or direct translumbar embolization (n = 13) during an 18-month period. Embolization success was defined as resolution of endoleak on all subsequent computed tomography angiogram results. The likelihood of embolization failure between the two treatments was expressed as a risk ratio and was compared with Fisher exact test., Results: Sixteen of 20 transarterial inferior mesenteric artery embolizations (80%) failed with recanalization of the original endoleak cavity over time. A single failure (8%) in the direct translumbar embolization group occurred in a patient in whom a new attachment site leak developed. The remaining 12 translumbar endoleak embolizations (92%) were successful and durable, with a median follow-up period of 254 days. The patients who underwent transarterial inferior mesenteric artery embolization were significantly more likely to have persistent endoleak than were the patients who underwent treatment with direct translumbar embolization (risk ratio, 4.6; 95% confidence interval, 1.9 to 11.2; P =.0001)., Conclusion: The transarterial embolization of inferior mesenteric arteries for the repair of type 2 endoleaks is ineffective and should not be performed. Direct translumbar embolization of the endoleak is effective in the elimination of type 2 leaks and should be the therapy of choice when aggressive endoleak management is indicated.

Endovascular repair is a major treatment advance in patients with large infrarenal abdominal aortic aneurysms. Since the FDA approved two commercial devices 2.5 years ago, over 40,000 patients have undergone this procedure in the United States. Although we have learned a great deal, more than a few mysteries relating to the long-term performance of these devices remain. This results in never-ending surveillance protocols searching for graft failure and aneurysm expansion. One of the especially contentious issues is the management of type 2 endoleaks. Unlike other endoleaks that are related to problems with the graft and/or fixation, this type of leak occurs in patients with properly functioning devices. This is why so much controversy exists about whether or not these patients must be treated. Some advocate "watchful-waiting" intervention only when there is aneurysm expansion. Others routinely treat patients with type 2 endoleaks in an attempt to prevent expansion. As with most controversial topics, if you look carefully, there is more agreement than disagreement between the two groups. In this review, we will first describe the methods used for endoleak diagnosis and treatment. We will then review our current endoleak treatment algorithm and explain its rationale for use., (Copyright 2001, Elsevier Science (USA). All rights reserved.)