Search

Chimney endovascular aortic aneurysm repair (ch-EVAR) has become a valid alternative to treat complex aneurysms but the occurrence of contrast-induced kidney injury (CI-AKI) is poorly known. This study investigated the incidence and the impact of CI-AKI on post-operative outcomes after ch-EVAR. Consecutive patients who underwent ch-EVAR between July 2010 and 2021 were retrospectively included. CI-AKI was defined based on plasma creatinine levels within 7 days after the intervention according to the "Kidney Disease Improving Global Outcomes" (KDIGO) classification. Among 102 patients included, CI-AKI occurred in 14 cases (13.7%). The 30-day post-operative mortality and complications were significantly higher in patients who developed CI-AKI compared with those who did not (50 vs 9.1%, P = .001 and 57.1 vs 20.5%, P = .007). Over a median follow-up of 24 months (3-39), overall mortality was also significantly higher (78.6 vs 33.0%, P = .002). The pre-operative platelet-to-lymphocyte ratio (PLR) was significantly higher in patients who developed CI-AKI (224.5 vs 147.6, P = .008). CI-AKI is frequent after ch-EVAR and is associated with worse post-operative outcomes. This should increase awareness of clinicians to optimize preventive and therapeutic strategies.

Thoracoabdominal aneurysms pose technical challenges for endovascular repair due to involvement of visceral and renal vessels. We report a case series of four patients diagnosed with thoracoabdominal aneurysm who underwent complex endovascular repair with Fenestrated Device and chimney grafts (FEVARCh). FEVARCh is a technically feasible approach for repair of thoracoabdominal aneurysms that involve renal, superior mesenteric, and celiac arteries for patients not appropriate for open surgical repair. Further studies are needed to understand the implications of resultant Type 1a endoleaks and strategies to minimize the displacement of the main body graft with adjunct chimneys.

Purpose: To assess the incidence of migration after endovascular aneurysm sealing (EVAS) in conjunction with chimney grafts (chEVAS) for repair of abdominal aortic aneurysms (AAAs)., Materials and Methods: A retrospective, observational cohort study was conducted of 31 patients (mean age 75.7 years; 27 men) treated for juxtarenal AAA between April 2013 and December 2018 at single centers in New Zealand and the Netherlands. The majority of patients received >1 chimney graft (13 single, 13 double, and 5 triple) during chEVAS. Six patients had only the first postoperative scan, so the migration analysis was based on 25 patients., Results: Median seal length assessed on the first postoperative computed tomography scan was 36.5 mm. The assisted technical success rate was 93.5% with 2 technical failures. Median time to final imaging follow-up was 17 months in 25 patients. At the latest follow-up, there were no cases of caudal migration >10 mm. Freedom from caudal movement of 5 to 9 mm was estimated as 86.1% at 1 year and 73.9% at 2 years; freedom from clinically relevant migration (movement requiring reintervention) was 100% at both time intervals. However, at 3 years there were 2 cases of caudal movement of 5 to 9 mm and a type Ia endoleak warranting reintervention. No correlation between migration and aneurysm growth (p=0.851), endoleak (p=0.562), or the number of chimney grafts (p=0.728) was found. During follow-up, 2 patients (7%) had aneurysm rupture and 10 (33%) had reinterventions. Eight patients (27%) died; 2 were aneurysm-related (7%) and due to the consequences of a reintervention., Conclusion: In the 2 years following chEVAS, there was no caudal migration >10 mm, but nearly a quarter of patients had caudal movement of 5 to 9 mm. A trend was observed toward ongoing migration that required intervention at 3-year follow-up. chEVAS is technically challenging and should be considered only for patients with no viable alternative treatment option.

Purpose: To evaluate the midterm outcomes of thoracic endovascular aortic repair (TEVAR) using chimney grafts (ch-TEVAR) or thoracic stent-grafts with fenestrations made on the back table (f-TEVAR) to treat thoracic aortic dissection (TAD) and thoracic aortic aneurysm (TAA). Materials and Methods: A retrospective analysis was conducted of 474 consecutive patients (mean age 62.3±10.7 years; 346 men) treated with either f-TEVAR (n=110) or ch-TEVAR (n=364) for 352 TADs (81 f-TEVAR and 271 ch-TEVAR) or 122 TAAs (29 f-TEVAR and 93 ch-TEVAR) from 2008 to 2016. The primary endpoints at 30 days and during follow-up were overall mortality, aorta-related mortality, and major complications. The secondary endpoints were endoleak and reintervention. The patency of the target branches, cost of hospitalization, and the use of antiplatelet drugs were also analyzed. Results: Intraoperative type I endoleaks were treated in 69 (14.6%) cases (4 f-TEVAR and 65 ch-TEVAR, p<0.01) to achieve 100% technical success. Four (0.8%) patients died within 30 days [1 (0.9%) f-TEVAR and 3 (0.8%) ch-TEVAR]. Perioperative cerebral ischemia (1 fatal stroke) occurred in 9 (1.9%) patients: (1 f-TEVAR and 8 ch-TEVAR, p=0.39). During the mean follow-up of 50.6±20.0 months (49.5±18.3 months in f-TEVAR and 50.9±20.6 months in ch-TEVAR), 11 (2.3%) patients died of an aorta-related event. Type I endoleak was present in 40 (8.4%) patients (1 f-TEVAR and 39 ch-TEVAR, p<0.01). Eleven (2.3%) patients experienced stent-graft migration and 13 (2.7%) had a retrograde dissection. One hundred (16.9%) of the 593 branch stents occluded (4/75 in the f-TEVAR group and 96/518 in the ch-TEVAR group, p<0.01). The branch reintervention rate was 7.2% (34/474). The f-TEVAR group had a significantly higher probability of freedom from branch occlusion (92%) than the ch-TEVAR group (83%, p=0.007). Conclusion: Off-the-shelf techniques employing chimney grafts and homemade fenestrations are both suitable options for TAD and TAA involving the supra-aortic branches, with a low incidence of reintervention. Fenestrated TEVAR seems to have more favorable short- and midterm outcomes. Further study of these off-the-shelf techniques for aortic arch repair is warranted.

Purpose: To report the use of the Nellix endovascular aneurysm sealing (EVAS) system in the management of proximal stent-graft collapse associated with thrombosis following endovascular aneurysm repair (EVAR)., Case Report: A 76-year-old man was admitted for proximal collapse of an aortic extension following bifurcated AFX stent-graft implantation associated with chimney grafts in both renal arteries and the superior mesenteric artery 1 month prior. Imaging identified thrombosis of the aortic stent-graft and the iliac limbs. A Nellix EVAS was placed into the AFX stent-graft to recanalize the aneurysm lumen and address the aortic thrombosis. There was no endoleak, and the renovisceral chimney stent-grafts remained patent over a follow-up of 25 months., Conclusion: While further studies are required to generalize its use, EVAS appears to be feasible in the management of aortic stent-graft collapse.

Purpose: To analyze the results of isolated left subclavian artery (LSA) revascularization during thoracic endovascular aortic repair (TEVAR) using carotid-subclavian bypass (CSbp) or chimney grafts (CGs)., Methods: A retrospective multicenter, observational study identified 73 patients (mean age 68±13 years, range 22-87; 56 men) with acute or chronic thoracic aortic lesions who underwent TEVAR with isolated LSA revascularization using either CSbp (n=42) or CGs (n=31) from January 2010 and February 2017. Primary endpoints were TEVAR-related mortality, postoperative stroke, freedom from type Ia endoleak, and LSA patency., Results: Primary technical success was achieved in all cases. Early TEVAR-related mortality was 4.2% (CSbp 2% vs CG 6%, p=0.571). Two (3%) patients had major ischemic strokes (one in each group). Mean follow-up was 24±21 months (range 1-72; median 15). Estimated freedom from TEVAR-related mortality was 93%±3% (95% CI 84.3% to 97.0%) at 12 and 36 months, with no significant difference between CSbp and CG (p=0.258). Aortic reintervention did not differ between the groups (CSbp 5% vs CG 6%, p=0.356); nor did freedom from type Ia endoleak (CSbp 98% vs CG 87%, p=0.134). Gutter-related endoleaks occurred in 4 (13%) CG patients, but none of the patients experienced sac enlargement or the need for reintervention and none died. Primary patency of the LSA was 100% for the entire group during the observation period., Conclusion: In our experience, LSA revascularization proved most satisfactory and equally effective with both the CSbp and CG techniques, without discernible differences at midterm follow-up.

Purpose: To report the results of the ASCEND Registry of cases involving endovascular aneurysm sealing (EVAS) in combination with chimney grafts (chEVAS) for the treatment of para- and juxtarenal aortic aneurysms (AAA)., Methods: A retrospective, multicenter registry established in 8 vascular centers between 2013 and 2016 recorded the treatment results and follow-up of chEVAS procedures for nonruptured AAAs; data were analyzed using standardized outcome measures. In the observation period, 154 patients (mean age 72.3±7.7 years; 124 men) underwent elective treatment for de novo juxtarenal and pararenal aneurysms and formed the study group., Results: Sixty-two (40.3%) of the cohort were treated using a single parallel graft, 54 (35.1%) with double chimneys, 27 (17.5%) with triple chimneys, and 11 (7.1%) with 4 chimneys. The 30-day mortality was 2.8%, and there were 4 perioperative strokes (1 fatal). At 1 year, the freedom from all-cause mortality was 89.8% and the freedom from aneurysm-related mortality was 94.3%. There were 3 endoleaks within 90 days of the procedure, one type Ia and 2 type Ib. The freedom from type Ia endoleaks was 95.7% at 1 year. There were no types II or III endoleaks in this series; the freedom from all endoleaks was 94.2% at 1 year. Freedom from reintervention at 1 year was 89.2%. Target vessel patency rates at 1 year were 97.7%, 99.3%, 100%, and 100% for the left renal, right renal, superior mesenteric artery, and celiac axis stents, respectively., Conclusion: The ASCEND Registry supports a proof of concept for the use of polymer technology and EVAS with parallel grafts in managing patients with complex aortic disease. The future role of chEVAS will be defined by studies that assess mid- to long-term durability.

Purpose: To describe 2 patients with a distally migrated endograft causing a type Ia endoleak and treatment with a proximal cuff and chimney grafts that required EndoAnchors to finally seal the leak., Case Report: Two men, ages 86 and 72 years, presented with stent-graft migration and type Ia endoleak at 5 and 15 years after endovascular repair, respectively. Both were treated with a proximal cuff in combination with a chimney graft to the left renal artery. In both cases, the type Ia endoleak persisted, likely due to gutter formation. Both patients were treated in the same setting with EndoAnchors that instantly resolved the endoleak. At 1-year follow-up, there was no recurrent endoleak or migration, with patent chimney grafts and renal arteries and stable renal function., Conclusion: EndoAnchors may effectively resolve a persistent type Ia endoleak arising from gutter formation after placement of a proximal cuff and chimney grafts., (© The Author(s) 2015.)

Purpose: To evaluate the midterm outcomes of chimney and/or periscope grafts (CPGs) in patients presenting type I endoleak after a previous endovascular aneurysm repair (EVAR)., Methods: Between June 2002 and April 2014, 24 consecutive patients (mean age 73.9±9.2 years; 23 men) presenting a type I endoleak were addressed with CPGs to extend the proximal and/or distal landing zone and to maintain side branch perfusion. Indication for treatment was a type Ia endoleak in 23 (96%) patients and a type Ib endoleak in one. Median interval from the previous EVAR to endoleak treatment with CPGs was 52.2±48.9 months (range 0.2-179). All patients had proximal/distal landing zones precluding any standard endovascular reintervention. Measured outcomes included technical success and perioperative mortality and morbidity. Technical success was defined as a procedure completed as intended, with no secondary procedures within 30 days. Midterm outcomes included survival, CPG patency, endoleaks, and freedom from reintervention., Results: Technical success was 96%; a single patient required an additional procedure to seal a recurrent type Ia endoleak. Intraoperative revascularization of all 55 target vessels (2.3/patient) with CPGs was successful. One (4%) patient died within 30 days. Estimated survival at 12, 24, and 36 months was 83%; estimated CPG patency at the same intervals was 94%. Over a mean follow-up of 23.4±29 months, 6 (25%) reinterventions were performed; of these, 4 were secondary to type I endoleak. Aneurysm diameters reduced from 88.3±26 to 85.5±33 mm (p=0.49) over the mean follow-up., Conclusion: The CPG technique is a safe and effective tool for treatment of type I endoleak after previous EVAR. The CPG technique is feasible even in nonelective patients, with excellent outcomes in terms of patency. Close imaging follow-up is warranted to rule out recurrent or de novo endoleaks., (© The Author(s) 2015.)

Purpose: To determine the impact of renal artery angulation on time to successful renal artery cannulation and procedure efficiency during fenestrated and snorkel/chimney endovascular aneurysm repair (EVAR)., Methods: The imaging and procedure logs of 77 patients (mean age 74.2 years; 63 men) who underwent complex EVAR (24 fenestrated, 53 snorkel/chimney) from 2009 to 2013 were reviewed. Renal artery angulation was measured on preoperative computed tomographic angiography scans. Time to renal artery cannulation was retrieved from the EVAR procedure logs and compared to preoperative renal artery angulation and other metrics of procedure efficiency (eg, procedure time, fluoroscopy time, blood loss, etc). In all, 111 renal arteries were available for renal artery angulation measurement (39 fenestrated, 72 snorkel/chimney); 22 renal cannulations were inappropriate for the comparative analyses due to concomitant visceral artery stenting (n=15), combined procedures (n=6), or unsuccessful cannulation (n=1)., Results: For patients undergoing fenestrated EVAR, mean renal artery angulation was -28°±21° (range +37° to -60°), not significantly different (p=0.66) from patients receiving snorkel/chimney grafts (mean -30°±19°, range +22° to -65°). Comparative analysis using median renal artery angulation (-30° for both groups) demonstrated that renal artery cannulation during fenestrated EVAR was performed significantly faster in arteries with less downward (≥ -30°) angulation (16.0 vs 32.8 minutes, p=0.04), whereas cannulation in snorkel/chimneys was faster in arteries with greater downward (< -30°) angulation (10.9 vs 17.3 minutes, p=0.05). Fenestrated EVAR cases involving less downward (≥ -30°) renal artery angulation were also associated with shorter overall procedure time (187.7 vs 246.2 minutes, p=0.01) and decreased fluoroscopy time (70.3 vs 98.2 minutes, p=0.04). Immediate renal function decline, procedural complications, and postoperative issues were not associated with renal artery angulation., Conclusion: Procedural efficiency may be optimized by considering renal artery angulation as one of several objective variables used in the selection of an appropriate endovascular strategy. The fenestrated approach is more efficient with less downward angulation to the renal arteries, while the snorkel/chimney strategy is facilitated by more downward renal artery angulation., (© The Author(s) 2015.)

Purpose: To demonstrate the feasibility of emergent endovascular repair of a ruptured pararenal aneurysm using chimney grafts and the Nellix endovascular aneurysm sealing (EVAS) system to reduce the potential for endoleak from the gutters around the chimney grafts., Case Report: A 74-year-old patient presented with a ruptured pararenal aneurysm. Because of anatomical considerations after previous aortic surgery, conventional endovascular aneurysm repair was deemed impossible. It was decided to exclude the aneurysm with a Nellix EVAS system in conjunction with two chimneys to the renal arteries, even though this was outside the instructions for use of the device. Active bleeding was stopped directly after positioning the chimneys and filling the endobags with polymer. Completion angiography showed aneurysm exclusion and patent renal arteries. Renal function remained stable, and the patient was discharged at the third postoperative day. At 6 months, duplex ultrasound and computed tomography showed patent stents and chimneys and no evidence of endoleak., Conclusion: Using chimney grafts in combination with the Nellix endoprosthesis in a ruptured pararenal aneurysm is feasible. However, more robust data on both chimney-EVAS and EVAS in ruptured cases are required., (© The Author(s) 2015.)

Purpose: To review the literature on pararenal endovascular aneurysm repair (EVAR) to determine the frequency and clinical relevance of chimney graft occlusions., Methods: A comprehensive search of the English-language literature abstracted in the Medline and the Cochrane Library databases was performed to identify case series involving pararenal aortic pathologies (degenerative aneurysms, penetrating atherosclerotic ulcers, type Ia endoleaks, and para-anastomotic aneurysms) treated with EVAR and chimney grafts; thoracoabdominal, iliac, or aortic arch chimney graft placements were excluded, as were case reports in which the total number of chimney grafts implanted at the reporting center could not be determined. The literature search identified 83 studies regarding chimneys/snorkels for pararenal pathologies published between January 2007 and March 2014. Of these, 7 studies met the inclusion criteria and were included in the analysis., Results: There were 15 (4.5%) occlusions in the overall 334 renovisceral vessels in which chimney grafts were deployed. The mean time to chimney graft occlusion was 3.5 months (range 1-270 days) over a mean follow-up of 1.4 months (range 9-24). The target arteries were the renal artery (n=12) and the superior mesenteric artery (SMA; n=3). Seven patients were asymptomatic, and no description was given in 5 cases. In the other 3 patients, the symptoms were acute renal failure, intestinal ischemia, and malignant hypertension. The treatment strategy included open conversion and iliorenal bypass (n=1), exploratory laparotomy to revascularize the SMA (n=1), hemodialysis (n=1), placement of bare metal stents (n=4), conservative treatment (n=2), and unknown (n=6). One (6.7%) patient died (an occluded SMA). Two patients with renal chimney occlusion suffered from temporary renal function deterioration., Conclusion: The present analysis identified a low rate of chimney graft occlusions, which appear to occur generally a few months after placement. Involvement of the renal artery had no severe clinical consequences, while occlusion of the SMA can be associated with life-threatening complications. More detailed information regarding occluded chimney grafts will be needed in future publications to help identify the causes., (© The Author(s) 2015.)

Purpose: To evaluate the safety and success of target vessel cannulation in the visceral aortic segment using the Magellan robotic catheter system (RCS) during complex endovascular aortic procedures., Methods: Robotic navigation was attempted for access to 37 target vessels in 15 patients (14 men; mean age 75±10 years) during 16 fenestrated and/or branched stent-grafting procedures and 1 endovascular repair requiring the chimney technique. For each target vessel, robotic navigation was attempted for a maximum of 15 minutes; if cannulation was unsuccessful in that time, manual catheters were employed. Safety was evaluated by recording intraoperative adverse events, intraoperative complications related to robotic navigation, and postoperative complications. Technical success of robotic cannulation, wire cannulation times, and times for inserting the leader over the wire in the target vessels were recorded to assess RCS performance., Results: Successful robotic cannulation was achieved for 30 (81%) of the 37 target vessels, with a median wire cannulation time of 263 seconds (range 40-780) and a median 15 seconds (range 5-450) for inserting the leader over the wire. No intraoperative complications related to robotic navigation were observed. Seven of 27 arteries accessed via 7 fenestrations could not be cannulated within 15 minutes; all were cannulated successfully using conventional catheters (mean cannulation time 31±7 minutes). All 10 target vessels accessed via branches and chimney stents were successfully cannulated with the RCS., Conclusion: Cannulation of target vessels with the RCS during complex endovascular aortic procedures is feasible and safe. The robotic system was particularly effective for branched and chimney stents., (© The Author(s) 2015.)

Purpose: To evaluate the impact of renal chimney grafts on anatomical suitability for endovascular aneurysm repair (EVAR) in ruptured abdominal aortic aneurysm (rAAA)., Methods: Contrast-enhanced computed tomography images of 206 patients with rAAA [175 men (mean age 75 ± 7.8 years) and 31 women (mean age of 76 ± 7.5 years)] were evaluated in a dedicated 3-dimensional vascular workstation. Assessment of infrarenal EVAR suitability was based on predefined anatomical variables reflecting the Instructions for Use of commercially available stent-grafts. In patients where aneurysm neck length was the only limiting factor for suitability, reevaluation of the proximal sealing zone was done, accounting for chimney grafts in one or both renal arteries., Results: Seventy (34%) rAAA patients were anatomically suitable for EVAR: 65 (37%) of 175 men and 5 (16%) of 31 women (p < 0.01). Eighty-nine (65%) of the 136 unsuitable patients had aneurysm necks < 15 mm long; short neck was the only exclusion criterion in 33 (24%) cases. In the 33 short-necked aneurysms without other limiting factors, a proximal sealing zone > 15 mm could potentially be achieved with one or two renal chimney grafts in 12 (36%) and 25 (76%) patients, respectively, increasing overall suitability to 40% and 46%. If access issues could also be solved and a similar strategy with chimneys for the renal arteries was applied, the EVAR suitability would increase further to 58%., Conclusion: Roughly one third of patients with rAAA are anatomically suitable for EVAR; short aneurysm neck is the most common exclusion criteria. In appropriate cases, chimney grafts in one or both renal arteries may increase overall suitability by 12%. Suitability increases to ~ 60% when iliac access issues are additionally overcome., (© The Author(s) 2015.)

Purpose: To investigate in an in vitro juxtarenal aneurysm flow model the feasibility and efficacy of using a sac-sealing endoprosthesis in a chimney graft configuration., Methods: In two experiments, a Nellix sac-sealing endoprosthesis was used as the main graft in a double-branched chimney graft configuration, using a self-expanding Viabahn stent-graft and a balloon-expandable Advanta V12 stent-graft in a pressurized silicone juxtarenal aneurysm flow model. In two consecutive experiments, the chimney graft balloons were inflated (1) at the beginning of and (2) to simulate varying renal ischemic times half-way through the injection of the sac-sealing polymer into the Nellix endobags. The balloons and were kept inflated until the endobags were filled and the polymer was cured. The aneurysm model was connected to a roller pump, pumping gelatin-water at a rate of 100 beats per minute. Before and after 24 hours of continuous flow, computed tomography (CT) scans were made using contrast injection. The CT scans were reconstructed and analyzed for gutter cross-sectional area, total gutter volume, chimney graft compression, and volume of space between the aneurysm wall and the endoprosthesis., Results: Differences in gutter size between both types of chimney grafts were minimal. Chimney graft compression exceeded 50% if the balloons were inflated in the chimney grafts halfway through polymer injection into the endobag. Twenty-four hours of flow did not influence chimney graft patency or gutter size., Conclusion: In a juxtarenal aneurysm flow model, we demonstrated the technical feasibility of a sac-sealing endoprosthesis in a chimney graft configuration. This early evidence suggests that balloon dilation of chimney grafts should occur over the entire period of polymer injection and curing to prevent considerable chimney graft compression.

Purpose: To show the feasibility of the Nellix device in conjunction with a chimney technique for treating juxtarenal aneurysms in two patients who were deemed unsuitable for fenestrated endovascular aneurysm repair or open surgery., Case Reports: Two men aged 83 and 81 years were referred with a juxtarenal abdominal aortic aneurysm (66 and 69 mm, respectively). Both were considered for open surgery as well as custom-made fenestrated stent-graft but deemed unsuitable for both options. They were both treated using the Nellix endoprosthesis in combination with chimney grafts to preserve the renal arteries. Technical success was achieved in both cases, with successful aneurysm exclusion and target vessel preservation (the right renal artery in the first case and both renal arteries in the second). At 6 months, duplex ultrasound and computed tomographic angiography of the first patient showed no signs of endoleak and patent renal arteries. The second patient developed a right retroperitoneal hematoma with minor extravasation near the lower pole of the right kidney for which coil embolization was necessary. The subsequent clinical sequelae led to respiratory insufficiency and ultimately death., Conclusion: The use of the Nellix endoprosthesis combined with chimney grafts is technically feasible. The addition of chimney grafts can increase the applicability of endovascular aneurysm sealing to treat short-neck and juxtarenal aneurysms. Further studies are needed to confirm these findings and establish longer term outcome.

Purpose: To present treatment of a juxtarenal aneurysm using the Nellix endovascular aneurysm sealing system (EVAS) and a chimney stent., Case Report: A 79-year-old woman was diagnosed with a 6-cm juxtarenal aneurysm. Standard endovascular aneurysm repair was not possible due to lack of an adequate infrarenal landing zone, and poor iliac access and angulated visceral aortic branches precluded a custom-made fenestrated solution. The patient was not a suitable candidate for open surgery due to significant comorbidity, so she underwent successful endovascular aneurysm repair with the Nellix EVAS system and a renal chimney stent. Follow-up imaging at 6 months showed a sealed aneurysm sac and patent renal chimney stent., Conclusion: The Nellix EVAS system obliterates the aneurysm sac using polymer-filled endobags. The ability of the endobags to conform to adjacent structures may offer advantages over conventional endografts when combined with parallel grafts designed to treat juxtarenal aneurysms.