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Objective: The impact of sex upon outcomes in acute limb ischemia (ALI) remains disputed. We aim to quantify the effect of sex upon amputation-free survival (AFS) after a percutaneous-first approach for ALI., Methods: This was a two-center retrospective review of ALI managed via a percutaneous-first approach. Demographics, comorbidities, and clinical characteristics were analyzed. The Kaplan-Meier and Cox regression were used to estimate AFS, limb salvage, and overall survival., Results: Over 9 years, 170 patients (n = 87, 51% males; median age, 67 [interquartile range (IQR), 59-77 years) presented with ALI. Rutherford classification was I in 56 (33%); IIa in 85 (50%); IIb in 20 (12%), and III in 9 (5%). Thirty-day mortality, major amputation rate, and fasciotomy rates were 8% (n = 13); 6.5% (n = 11), and 4.7% (n = 8), respectively. Among revascularized limbs, 92% were patent at 30 days. Length of stay was 7 days (IQR, 3-11 days). Complications included 13 bleeding episodes (8%), four cases of atrial fibrillation (2%), and three re-thrombosis/clot extension events (1.7%). No differences were noted in complication rates when stratified by sex. Females were older than males (median age, 70 [IQR, 62-79] vs 65 [IQR, 56-76 years]; P = .02) and more likely to present with atrial fibrillation (20.5% vs 8%; P = .02) and hyperlipidemia (72% vs 57%; P = .04). Females also more frequently presented with multi-level thrombotic/embolic burden compared with males (56% vs 43%; P = .03) and required both aspiration thrombectomy and thrombolysis (27% vs 14%; P = .02). Kaplan-Meier estimated median AFS, limb salvage, and overall survival were 425 days (IQR, 140-824 days); 314 days (IQR, 72-727 days); and 342 days (IQR, 112-762 days). When stratified by sex, females had worse survival (median, 270 days [IQR, 92-636 days] vs 406 days [IQR, 140-937 days]; P = .005) and limb salvage (median, 241 days [IQR, 88-636 days] vs 363 days [IQR, 49-822 days]; P = .04) compared with males. Univariate Cox regression showed female sex (hazard ratio [HR], 1.46; 95% confidence interval [CI], 1.04-2.05; P = .03), multi-level thrombotic/embolic burden (HR, 1.64; 95% CI, 1.17-2.31; P = .004), and Rutherford class (HR, 1.37; 95% CI, 1.08-1.73; P = .009) predicted major amputation/death. By multivariable Cox regression, multi-level thrombotic/embolic burden (HR, 1.54; 95% CI, 1.09-2.17; P = .01), Rutherford class (HR, 1.34; 95% CI, 1.07-1.69; P = .01), and female sex (HR, 1.45; 95% CI, 1.03-2.05; P = .03) were each independently predictive of major amputation/death., Conclusions: A percutaneous-first strategy is safe and efficacious in the overall ALI population. Similar to prior works, female vs male patients with ALI in our cohort have higher rates of mortality and major amputation. In our multivariable model, multi-level thrombotic/embolic burden was independently associated with a greater than 45% increased hazard of major amputation/death at last follow-up. Further prospective analysis is warranted to elucidate the underlying factors contributing to the higher prevalence of multi-level thrombotic/embolic burden in female patients with ALI, and to further define the optimal percutaneous-first approach for ALI in consideration of patient sex and extent of clot burden., Competing Interests: Disclosures None., (Copyright © 2024 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: This systematic review aims to comprehensively assess the contemporary literature on platelet function testing (PFT) in individuals undergoing revascularization therapy for peripheral arterial disease (PAD). The goal is to identify whether PFT can aid in detecting antiplatelet resistance, predicting post-procedural thrombotic complications, and informing tailored treatment strategies., Methods: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a literature review was conducted using PubMed databases. Search terms included relevant medical subject headings (MeSH) terms. Eligible articles published in English between 1990 and 2023 were analyzed. Studies that examined PFT outcomes in patients with PAD after lower extremity revascularization were included., Results: Ten studies met the inclusion criteria. Various PFT methods were used, including thromboelastography with platelet mapping, multiplate analyzer, Cytochrome P450 2C19 testing, VerifyNow, corrected whole blood aggregometry, platelet function analyzer-100, and light transmission aggregometry. PFT identified individuals who were resistant or non-sensitive to antiplatelet therapy, with such patients facing increased risks of graft/stent thrombosis, amputation, and reintervention. However, substantial heterogeneity in surgical procedures, drug regimens, and testing methods was observed among the studies., Conclusions: PFTs can play a crucial role in detecting resistance and non-sensitivity to antiplatelet drugs in patients with PAD post-revascularization. However, heterogeneity of data and methods underlines the need for standardized protocols and consensus-building among PFTs. Enhancing clinical utility and reliability could help optimize antiplatelet thromboprophylaxis, minimize thrombotic complications, and improve treatment strategies in vascular surgery. Further research is necessary to solidify the role of PFTs in guiding antiplatelet therapy post-revascularization in patients with PAD., Competing Interests: Disclosures None., (Copyright © 2023 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: We compared the outcomes of patients treated with nonbare stents (NBS) and proximal bare stents (PBS) endografts with a proximal landing zone in the aortic arch during thoracic endovascular aortic repair (TEVAR)., Methods: We conducted a retrospective cohort, observational, multicenter study that included 361 consecutive TEVAR procedures undertaken between November 2005 and December 2021. TEVAR patients with both BS and NBS Relay stent graft configurations with proximal landing in zones 1, 2, or 3 were enrolled. Preoperative anamnestic and morphological data, clinical outcomes, and aortic modifications 30 days after surgery and at the latest follow-up available were collected. The primary outcome was freedom from proximal endoleak (type IA) comparing the two configurations. Total and detailed endoleak rates, clinical and technical success, intraoperative additional maneuvers, major adverse events, and reinterventions were secondary outcomes., Results: The median follow-up was 4.9 (interquartile range, 2.0-8.1) years. No statistically significant difference between NBS and PBS patients concerning 30-day major adverse events, retrograde aortic dissection, disabling stroke, or late type IA endoleak (10.8% vs 7.8%; P = .597). Aneurysmal disease (P = .026), PLZ diameter of >34 mm (P = .026), aortic tortuosity index of >1.4 (P = .008), type III aortic arch (P = .068), and PLZ thrombus (P = .014) identified as risk factors by univariate Cox regression analysis. PLZ thrombus was the only type IA endoleak risk factor at multivariate Cox regression (P = .016)., Conclusions: We found no statistically significant difference in freedom from type IA endoleak, retrograde dissection, or disabling stroke observed between the NBS and the BS configuration of the Relay endograft. Proximal landing zone thrombotic apposition was a prominent risk factor for type IA endoleak after TEVAR., Competing Interests: Disclosures None., (Copyright © 2023 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Aortic endarterectomy (AE), once a treatment of choice for aortoiliac occlusive disease, is now rarely performed in favor of endovascular procedures or open aortobifemoral bypass. However, in select patients with paravisceral or aortoiliac occlusive disease, AE remains a viable alternative for revascularization, either as a primary procedure or after prior interventions have failed. Here, we evaluated outcomes for an extended series of patients undergoing paravisceral or aortoiliac endarterectomy, demonstrating that these procedures can be an excellent alternative with acceptable morbidity and mortality in properly selected patients., Methods: A single institution retrospective review of 20 patients who underwent AE from 2017 to 2023 was performed., Results: Five patients (25%) underwent paravisceral endarterectomy and 15 (75%) underwent aortoiliac endarterectomy. There were no perioperative mortalities. One paravisceral patient died 3 months postoperatively from complications of pneumonia. Three patients in the paravisceral group required reinterventions; one acutely due to thrombosis of the superior mesenteric artery (SMA) requiring extension of the endarterectomy and patch angioplasty on postoperative day 0, one due to stenosis at the distal edge of the endarterectomy 1 month postoperatively, successfully treated with SMA stenting, and one at 10-month follow-up due to SMA stenosis at the distal aspect of the endarterectomy, also successfully treated with SMA stenting. With these reinterventions, the 1-year primary patency in the paravisceral group was 40%, primary-assisted patency was 80%, and secondary patency was 100%. In the aortoiliac group, 1-year primary, primary-assisted, and secondary patency were 91%, 91%, and 100%, respectively. One patient developed iliac thrombosis 10 days postoperatively owing to an intimal flap distal to the endarterectomy site. She and one other patient, a young man with an undefined hypercoagulable disorder, ultimately required neoaortoiliac reconstructions at 18 and 32 months postoperatively, respectively (the latter in the setting of stopping anticoagulation). The remaining 13 patients experienced no complications. All patients had rapid resolution of clinical symptoms, and median postoperative ankle-brachial indexes of 1.06 on the right and 1.00 on the left, representing a median improvement from preoperative ankle-brachial indexes of +0.59 on the right and +0.56 on the left (P < .01 and P < .01)., Conclusions: In this series of 20 patients undergoing paravisceral and infrarenal aortoiliac endarterectomy, AE was associated with no perioperative mortality, relatively low and manageable morbidity, and excellent clinical outcomes in patients with both paravisceral and aortoiliac occlusive disease. SMA-related early reintervention was not uncommon in the paravisceral group, and attention should be given particularly to the distal endarterectomy site. AE remains a viable treatment for severe multivessel paravisceral or aortoiliac occlusive disease isolated to the aorta and common iliac arteries in select patients., Competing Interests: Disclosures None., (Copyright © 2023 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Paraplegia is one of the most feared complications after thoracoabdominal aortic aneurysm repair. The purpose of this study is to determine whether aortic thrombus characteristics are associated with spinal cord ischemia (SCI) after branched endovascular aneurysm repair (BEVAR)., Methods: From April 2011 to April 2020, 62 patients underwent elective BEVAR for thoracoabdominal aortic aneurysm and pararenal aortic aneurysms using a low-profile device and had a complete preoperative computed tomography angiography of the aorta from the sinotubular junction to the aortic bifurcation. Aortic thrombus was evaluated for thrombus thickness ≥5 mm, thrombus >2/3 of aortic circumference, and the presence of an ulcer-like thrombus. One point was assigned at each 5 mm axial image if all 3 criteria were met, resulting in a total "shaggy score" for the entire aorta. Data on demographics, procedural details, and outcomes were collected prospectively. All patients underwent a standard spinal cord protection protocol, including routine cerebrospinal fluid drainage. In July 2016, an insulin infusion protocol (IIP) was initiated to maintain postoperative blood glucose levels <120 mg/dL for 48 hours. The primary clinical end point was postoperative SCI., Results: 10 (16%) patients developed postoperative SCI: 6 with transient paraparesis, 2 with persistent paraparesis, and 2 with persistent paraplegia. Patients with SCI were older, had higher shaggy scores, and were less likely to have been on an IIP. There were no significant differences in demographics, aneurysm type, or operative parameters. In a logistic multivariate regression model for SCI, age (odds ratio [OR]: 1.2 [1.1-1.4], P = .02) and shaggy score (OR: 1.2 [1.1-1.4], P = .02) were independently associated with increased risk of SCI, whereas treatment with the IIP was associated with lower risk of SCI (OR: 0.04 [0.006-0.50], P = .05). Of the individual components of the shaggy score, higher descending thoracic aortic ulcer scores were the most strongly associated with postoperative SCI (P = .009)., Conclusions: Preoperative characterization of aortic wall thrombus is an important adjunctive tool for individualized clinical decision-making and patient counseling about the risk of SCI after BEVAR., Competing Interests: Disclosures J.H. has received royalties from licensed patents to Cook Medical (spouse). All other authors declare nothing to disclose relevant to this work., (Copyright © 2023 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Acute limb ischemia (ALI) is associated with high rates of amputation and consequent morbidity and mortality. The objective of this study is to report on the safety and efficacy of aspiration thrombectomy using the Indigo Aspiration System in patients with lower extremity (LE) ALI., Methods: The STRIDE study was an international, multicenter, prospective, study that enrolled 119 participants presenting with LE-ALI. Patients were treated firstline with mechanical thrombectomy using the Indigo Aspiration System, before stenting or angioplasty, or other therapies as determined by treating physician. The primary end point was target limb salvage at 30 days after the procedure. Secondary end points within 30 days included technical success, defined as core laboratory-adjudicated Thrombolysis in Myocardial Infarction (TIMI) 2/3 flow rate immediately after the procedure, changes in modified Society for Vascular Surgery runoff score, improvement of Rutherford classification compared with before the procedure, patency, rate of device-related serious adverse events, and major periprocedural bleeding. Secondary end points that will be evaluated at 12 months include target limb salvage and mortality., Results: Of the 119 participants enrolled at 16 sites, the mean age was 66.3 years (46.2% female). At baseline (n = 119), ischemic severity was classified as Rutherford I in 10.9%, Rutherford IIa in 54.6%, and Rutherford IIb in 34.5%. The mean target thrombus length was 125.7 ± 124.7 mm. Before the procedure, 93.0% (of patients 107/115) had no flow (TIMI 0) through the target lesion. The target limb salvage rate at 30 days was 98.2% (109/111). The rate of periprocedural major bleed was 4.2% (5/119) and device-related serious adverse events was 0.8% (1/119). Restoration of flow (TIMI 2/3) was achieved in 96.3% of patients (105/109) immediately after the procedure. The median improvement in the modified Society for Vascular Surgery runoff score (before vs after the procedure) was 6.0 (interquartile range, 0.0-11.0). Rutherford classifications also improved after discharge in 86.5% of patients (83/96), as compared with preprocedural scores. Patency at 30 days was achieved in 89.4% of patients (101/113)., Conclusions: In the STRIDE (A Study of Patients with Lower Extremity Acute Limb Ischemia to Remove Thrombus with the Indigo Aspiration System) study, aspiration thrombectomy with the Indigo System provided a safe and effective endovascular treatment for patients with LE-ALI, resulting in a high rate (98.2%) of successful limb salvage at 30 days, with few periprocedural complications., Competing Interests: Disclosures T.M. reports a consulting agreement with Penumbra. P.M. reports a speaker/consultant disclosure with Penumbra. F.A. reports a speaker/consultant disclosure Penumbra. The remaining authors report no conflicts., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: Maintenance of long-term arteriovenous access is important in long-term care for patients with end-stage renal disease. Arteriovenous access is associated in the long term with the development of fistula aneurysms (FAs). This study aims to evaluate the outcomes of staged FA treatment in dialysis access arteriovenous fistulae (AVF)., Methods: A retrospective review of all patients over a 12-year period with primary autogenous AVF was undertaken at a single center. Patients undergoing elective open aneurysm repair were identified and were categorized into three groups: single FA repair (single, control group) and staged and unstaged repair of two FAs (staged and unstaged). A staged repair was a procedure in which the initial intent was to treat both aneurysms in the AVF and in which the most symptomatic aneurysm was treated first. When the incision from the first surgery had healed, the second symptomatic aneurysm in the AVF was treated. An unstaged repair was a procedure in which the initial intent was to repair both symptomatic aneurysms simultaneously. All patients had a fistulogram before the FA repair. Thirty-day outcomes, cannulation failure, line placement, reintervention, and functional dialysis (continuous hemodialysis for 3 consecutive months) were examined., Results: Five hundred twenty-seven patients presented with FA that met requirements for open intervention; 44% underwent single FA repair, whereas the remaining 34% and 22% underwent staged and unstaged repair of two FAs, respectively. The majority of patients were diabetic and Hispanic. Ninety-one percent of the patients required percutaneous interventions of the outflow tract (37%) and the central veins (54%). Thirty-day major adverse cardiovascular events were equivalent across all modalities. Thirty-day morbidity and early thrombosis (<18 days) were significantly higher in the unstaged group (4.3%) compared with the two other groups (1.3% and 2.1%, single and staged, respectively), which led to an increased need for a short-term tunneled catheter (8.9%) compared with the two other groups (3.4% and 4.4%, single and staged, respectively), Unstaged repair resulted in an increased incidence of secondary procedures (5.0%) compared with the two other groups (2.6% and 3.1%, single and staged, respectively). Functional dialysis at 5 years was equivalent in the single and staged groups but was significantly decreased in the unstaged group., Conclusions: Open interventions are successful therapeutic modalities for FAs, but unstaged rather than staged repair of two concurrent FAs results in a higher early thrombosis, an increased secondary intervention rate, and a need for a short-term tunneled central line. Staged and single FA repairs have equivalent results. In the setting of two symptomatic FAs, staged repair is recommended., Competing Interests: Disclosures None., (Copyright © 2023 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: In the field of thoracoabdominal aortic aneurysm (TAAA) open surgical repair (OSR), some preoperative characteristics are established risk factors for adverse outcomes, whereas others are supposed to be relevant, but their role still need to be defined; among them, the presence of "shaggy aorta" (SA), an extensive and irregular atheroma within the aorta. The aim of this study is to report the results of a single-center large cohort of patients treated with OSR for TAAA with SA, comparing the outcomes with patients affected by TAAA without SA, and analyzing the impact of the scores for SA on the outcomes., Methods: All consecutive patients receiving OSR for TAAA between 2012 and 2021 were retrospectively analyzed. Clinical data from patients with degenerative TAAA were included and analyzed for preoperative characteristics and postoperative outcomes; patients with ruptured TAAA, and patients with aortic dissection were excluded from the analysis. Patients with degenerative aortic aneurysm, thrombus measurement in non-aneurysmal aortic segments (≤40 mm), atheroma thickness ≥5 mm, and finger-like thrombus projection were included in the SA group, whereas the others were included in the non-shaggy aorta group (NSA group). The SA group and NSA group were compared using a propensity-matched comparison. Preoperative computed tomography scans of patients in the SA group were also stratified according to SA grading scores., Results: A total of 58 patients with SA were identified (male, n = 43 [74.1%], mean age 70.1 ± 7.8 years) among 497 patients with TAAA treated with open surgical repair. After propensity matching, there were 57 patients in the SA group and 57 in the NSA group with correction of all differences in baseline characteristics. Patients in the SA group presented significantly higher in-hospital mortality (SA group, 14.0% vs NSA group, 3.5%; P = .047), postoperative acute renal failure (Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease [RIFLE], 3-5) (SA group, 21.1% vs NSA group, 5.3%; P = .013), and postoperative embolization (SA group, 28.1% vs NSA group, 8.8%; P = .008). Spinal cord ischemia and stroke rate were not significantly influenced by the presence of SA. In the SA group, 16 patients (27.6%) with end-organ embolization were compared with 42 patients (72.4%) without a documented embolization considering the grade of aortic "shagginess" and no significant difference was identified (P = .546)., Conclusions: Despite a better knowledge of the SA disease, new classifications, and intraoperative adjuncts, TAAA patients with SA treated with OSR have worse postoperative outcomes if compared with patients without SA. The presence of SA is a risk factor itself, whereas the grade of "shagginess" seems not to impact on postoperative outcomes., (Copyright © 2022 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Antiplatelet therapy has been a pillar of management for peripheral artery disease (PAD). However, a significant subset of patients with PAD will be resistant to certain antiplatelet medications and, therefore, have an increased risk of graft and/or stent thrombosis unknown to the surgeon. At present, no point-of-care testing to identity which patients will experience benefit from these medications has been incorporated into the treatment guidelines. Thromboelastography with platelet mapping affords an opportunity to evaluate real-time coagulation dynamics and platelet function. In the present prospective, observational study, we aimed to delineate the variation in response to antiplatelet therapy in patients with PAD undergoing revascularization., Methods: All patients who were undergoing named vessel revascularization during December 2020 through April 2022 were prospectively enrolled. Platelet mapping assays were performed in three clinical phases: preoperative, postoperative inpatient, and postoperative outpatient. The distribution of platelet reactivity within patients receiving mono- vs dual antiplatelet therapy was assessed, and a between-group inferential analysis was performed. The effect of comorbidities and intervention subtype on platelet inhibition was also analyzed., Results: A total of 521 platelet mapping samples from 143 individual patients were analyzed using thromboelastography with platelet mapping. We found wide variability in the distribution of platelet inhibition, with a range of 0 to 100 and an interquartile range of 37.6. Although platelet inhibition with clopidogrel 75 mg was higher on average (44.8 ± 30.2) than that with aspirin 81 mg (24.6 ± 23.7) or aspirin 325 mg (27.1 ± 26.4; P = .001), clopidogrel at 75 mg demonstrated the highest variability in response., Conclusions: These data have demonstrated significant variability in the response to both mono- and dual antiplatelet therapy in PAD patients undergoing lower extremity revascularization. Future research on the effect of this variability in response on the clinical outcomes could provide invaluable understanding of the perioperative thrombotic risk., (Copyright © 2022 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: The relationship between intraluminal thrombus (ILT) and abdominal aortic aneurysm (AAA) growth and rupture risk remains ambiguous. Studies have shown a limited effect of antiplatelet therapy on ILT size, whereas the impact of anticoagulant therapy on ILT is unresolved. This study aims to evaluate an association between antithrombotic therapy and ILT size assessed with three-dimensional contrast-enhanced ultrasound (3D-CEUS) examination in a cohort of patients with AAA., Methods: In a cross-sectional study, 309 patients with small AAAs were examined with 3D-CEUS. Patients were divided into three groups based on prescribed antithrombotic therapy: anticoagulant (n = 36), antiplatelet (n = 222), and no antithrombotic therapy (n = 51). Patient ILT size was calculated in volume and thickness and compared between the three groups., Results: Patients on anticoagulants had a significantly lower estimated marginal mean ILT volume of 16 mL (standard error [SE], ±3.2) compared with 28 mL (SE, ±2.7) in the no antithrombotic group and 30 mL (SE, ±1.3) in the antiplatelet group when adjusting for AAA volume (P < .001) and comorbidities (P < .001). In addition, patients on anticoagulant therapy had significantly lower estimated marginal mean ILT thickness of 10 mm (SE, ±1.1) compared with 13 mm (SE, ±0.9) in the no antithrombotic group of and 13mm (SE, ±0.4) in the antiplatelet group when adjusting for AAA diameter (P = .03) and comorbidities (P = .035)., Conclusions: A 3D-CEUS examination is applicable for ILT assessment and demonstrates that patients with AAA on anticoagulant therapy have lower ILT thickness and volume than patients with AAA on antiplatelet therapy and those without antithrombotic therapy. Causality between anticoagulants and ILT size, and extrapolation to AAA growth and rupture risk, is unknown and merits further investigations, to further nuance US-based AAA surveillance strategy., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: Beta-blockers (BBs) are first-line anti-impulse therapy for patients presenting with acute type B aortic dissection (TBAD). However, little is understood about their effects after aortic repair. The aim of the present study was to evaluate the role of postoperative BB use on the outcomes of thoracic endovascular aortic repair (TEVAR) in TBAD., Methods: The Vascular Quality Initiative database was queried for all patients who had undergone TEVAR for TBAD from 2012 to 2020. Aortic-related reintervention, all-cause mortality, and the effects of TEVAR on false lumen thrombosis of the treated aortic segment were assessed and compared between patients treated with and without BBs postoperatively. Cox proportional hazards models were used to estimate the effect of BB therapy on the outcomes., Results: A total of 1114 patients who had undergone TEVAR for TBAD with a mean follow-up of 18 ± 12 months were identified. The mean age was 61.1 ± 11.9 years, and 791 (71%) were men. Of the 1114 patients, 935 (84%) continued BB therapy at discharge and follow-up. The patients taking BBs were more likely to have had an entry tear originating in zones 1 to 2 (22% vs 13%; P = .022). The prevalence of acute, elective, and symptomatic aortic dissection, prevalence of concurrent aneurysms, number of endografts used, distribution of proximal and distal zones of dissection, and operative times were comparable between the two cohorts. At 18 months, significantly more complete false lumen thrombosis (58% vs 47%; log-rank P = .018) was observed for patients taking BBs, and the rates of aortic-related reinterventions (13% vs 9%; log-rank P = .396) and mortality (0.2% vs 0.7%; log-rank P = .401) were similar for patients taking and not taking BBs, respectively. Even after adjusting for clinical and anatomic factors, postoperative BB use was associated with increased complete false lumen thrombosis (hazard ratio, 1.56; 95% confidence interval, 1.10-2.21; P = .012) but did not affect mortality or aortic-related reintervention. A secondary analysis of BB use for those with acute vs chronic TBAD showed a higher rate of complete false lumen thrombosis for patients with chronic TBAD and taking BBs (59% vs 38%; log-rank P = .038). In contrast, no difference was found in the rate of complete false lumen thrombosis for those with acute TBAD between the two cohorts (58% vs 51%; log-rank P = .158). When analyzed separately, postoperative angiotensin-converting enzyme inhibitor use did not affect the rates of complete false lumen thrombosis, mortality, and aortic-related reintervention., Conclusions: BB use was associated with promotion of complete false lumen thrombosis for patients who had undergone TEVAR for TBAD. In addition to its role in the acute setting, anti-impulse control with BBs appears to confer favorable aortic remodeling and might improve patient outcomes after TEVAR, especially for those with chronic TBAD., (Copyright © 2022 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Hypercoagulability and thrombotic complications seen in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), as well as the associated pathophysiology, have been reported extensively. However, there is limited information regarding the factors related to this phenomenon and its association with the Coronavirus disease 2019 (COVID-19) Delta variant., Methods: A retrospective review including patients admitted to a tertiary center with a COVID-19 positive test and at least one acute thrombotic event confirmed by imaging between June 2020 and August 2021 was performed. We compared the rates of thrombotic events in patients with COVID-19 before and during the Delta peak. We also analyzed the association of the thrombotic complications with demographic characteristics, comorbidities, anticoagulation strategies, and prothrombotic markers while describing other complications secondary to COVID-19 infection., Results: Of 964 patients admitted with COVID-19 diagnosis, 26.5% (n = 256) had a thrombotic event evidenced by ultrasound or computed tomography scan. Venous thromboembolism was found in 60% (n = 153), arterial thrombosis in 23% (n = 60), and both venous and arterial thromboses in 17% (n = 17) of the study cohort. Of all patients, 94% were not vaccinated. Delta variant wave (DW) patients had thrombotic episodes in 34.7% (n = 50/144) of cases compared with 25% (n = 206/820) of non-Delta wave (NDW) patients, posing an estimated risk 1.36 times higher in patients infected with COVID-19 during the DW than NDW. Overall, DW subjects were significantly younger (P < .001) with lower body mass index (P = .021) compared with NDW patients. Statistical analyses showed African American patients were more likely to have arterial thrombosis compared with the other groups when testing positive for COVID-19 (odds ratio [OR], 1.78; 95% confidence interval [CI], 1.04-3.05; P = .035, whereas immunosuppressed patients had less risk of arterial thrombosis (OR, 0.38; 95% CI, 0.15-0.96; P = .042). Female gender (OR, 2.15; 95% CI, 1.20-3.85; P = .009) and patients with active malignancy (OR, 5.99; 95% CI, 2.14-16.78; P = .001) had an increased risk of having multiple thrombotic events at different locations secondary to COVID-19., Conclusions: COVID-19 infection is associated with elevated rates of thrombotic complications and an especially higher risk in patients infected during the Delta variant peak. We highlight the importance of vaccination and the development of new anticoagulation strategies for patients with COVID-19 with additional hypercoagulable risk factors to prevent thrombotic complications caused by this disease., (Copyright © 2022 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: To provide the 5-year outcomes of the use of a composite device (proximal covered stent graft + distal bare stent) for endovascular repair of patients with acute, type B aortic dissection complicated by aortic rupture and/or malperfusion., Methods: Study of Thoracic Aortic Type B Dissection Using Endoluminal Repair (STABLE) II was a prospective, multicenter study of the Zenith Dissection Endovascular System (William Cook Europe). Patients were enrolled between August 2012 and January 2015 at sites in the United States and Japan. Five-year follow-up was completed by January 2020., Results: In total, 73 patients (mean age: 60.7 ± 10.9 years; 65.8% male) with acute type B dissection complicated by malperfusion (72.6%), rupture (21.9%), or both (5.5%) were enrolled. Patients were treated with either a composite device (79.5%) or the proximal stent graft alone (no distal bare stent, 20.5%). Dissections were more extensive in patients who received the composite device (408.9 ± 121.3 mm) than in patients who did not receive a bare stent (315.9 ± 100.1 mm). The mean follow-up was 1209.4 ± 754.6 days. Freedom from all-cause mortality was 80.3% ± 4.7% at 1 year and 68.9% ± 7.3% at 5 years. Freedom from dissection-related mortality remained at 97.1% ± 2.1% from 1-year through 5-year follow-up. Within the stent-graft region, the rate of either complete thrombosis or elimination of the false lumen increased over time (82.1% of all patients at 5 years vs 55.7% at first postprocedure computed tomography), with a higher rate at 5 years in patients who received the composite device (90.5%) compared with patients without the bare stent (57.1%). Throughout the follow-up, overall true lumen diameter increased within the stent-graft region, and overall false lumen diameter decreased. At 5 years, 20.7% of patients experienced a decrease in maximum transaortic diameter within the stent-graft region, 17.2% experienced an increase, and 62.1% experienced no change. Distal to the treated segment (but within the dissected aorta), 23.1% of patients experience no change in transaortic diameter at 5 years; a bare stent was deployed in all these patients at the procedure. Five-year freedom from all secondary intervention was 70.7% ± 7.2%., Conclusions: These 5-year outcomes indicate a low rate of dissection-related mortality for the Zenith Dissection Endovascular System in the treatment of patients with acute, complicated type B aortic dissection. Further, these data suggest a positive influence of composite device use on false lumen thrombosis. Continuous monitoring for distal aortic growth is necessary in all patients., (Copyright © 2022 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Background: Persistent type II endoleak has necessitated prolonged surveillance and is a reason for reintervention after infrarenal endovascular aneurysm repair (EVAR). The aim of this study was to assess the association of thrombus burden (TB) within the aneurysmal sac in the prediction of a persistent type II endoleaks., Methods: Consecutive patients who underwent infrarenal EVAR from October 2009 to October 2017 in a single vascular network were included. TB was assessed on preoperative computed tomography angiogram and was defined as a percentage of thrombus across the maximal sac diameter in comparison with the luminal diameter measured orthogonally at the same level. Patients were categorized into three groups: low TB (<25%), medium TB (25%-50%), and high TB (>50%). All patients underwent postoperative EVAR surveillance comprising computed tomographic angiography or duplex ultrasound imaging. Type II endoleak observed for more than 1 year was defined as persistent type II endoleak. Odds ratio (OR) and Student's t-test were used to determine significance., Results: Some 275 EVARs were performed in the study period. A total of 45 procedures were excluded because of either iliac-only intervention (n = 9), no preoperative information (n = 7), abandoned (n = 1), or less than 1 year's follow-up data (n = 28). For the 230 procedures included, the median follow-up was 43 (12-102) months. There were no significant differences between the groups for age, gender, and comorbidities nor preoperative sac diameter. There was high interobserver reliability with a kappa value of 0.89 (0.84-0.94) with a total discordance of 7% across the cohorts. Persistent type II endoleak occurred significantly more frequently with reduced TB: 41% of the low TB cohort compared with 4% of the high TB cohort (OR, 15.36 [3.5-67.3]; P = .0003). Reintervention was also significantly more likely to occur in the presence of a persistent type II endoleak compared with its absence; n = 12 of 13 (92%) patients who underwent reintervention had a persistent type II endoleak (OR, 43.4 [5.5-242]; P = .0003). Sac size reduction was significantly greater in medium TB and high TB cohorts when compared with low TB: -25% and -27% vs -15% (P = .0046 and P < .0001). Decreased TB was associated with a significant increase in inferior mesenteric artery (IMA) patency, the mean TB, where the IMA was patent, being 29% compared with 40% where the IMA was occluded P < .0001. When considered together, patients with a low TB and a patent IMA were even more likely to have a persistent type II endoleak when compared with those with a high TB and an occluded IMA (OR, 34.1 [1.99-583]; P = .015)., Conclusions: Low TB is associated with increased rates of persistent type II endoleak, especially in the presence of a patent IMA. High TB is associated with increased sac regression and low reintervention rates. TB can be assessed reliably and could be used for risk stratification in the planning of infrarenal EVAR. Pre-emptive embolization of IMA or lumbar vessels in those with low TB may be beneficial. TB could be a useful tool for designing a post-EVAR surveillance regimen., (Copyright © 2022 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Background: Improved risk stratification is a key priority for type B aortic dissection (TBAD). Partial false lumen thrombus morphology is an emerging predictor of complications. However, partial thrombosis is poorly defined, and its evaluation in clinical studies has been inconsistent. Thus, we aimed to characterize the hemodynamic pressure in TBAD and determine how the pressure relates to the false lumen thrombus morphology and clinical events., Methods: The retrospective admission computed tomography angiograms of 69 patients with acute TBAD were used to construct three-dimensional computational models for simulation of cyclical blood flow and calculation of pressure. The patients were categorized by the false lumen thrombus morphology as minimal, extensive, proximal or distal thrombosis. Linear regression analysis was used to compare the luminal pressure difference between the true and false lumen for each morphology group. The effect of morphology classification on the incidence of acute complications within 14 days was studied using logistic regression adjusted for clinical parameters. A survival analysis for adverse aortic events at 1 year was also performed using Cox regression., Results: Of the 69 patients, 44 had experienced acute complications and 45 had had an adverse aortic event at 1 year. The mean ± standard deviation age was 62.6 ± 12.6 years, and 75.4% were men. Compared with the patients with minimal thrombosis, those with proximal thrombosis had a reduced false lumen pressure by 10.1 mm Hg (95% confidence interval [CI], 4.3-15.9 mm Hg; P = .001). The patients who had not experienced an acute complication had had a reduced relative false lumen pressure (-6.35 mm Hg vs -0.62 mm Hg; P = .03). Proximal thrombosis was associated with fewer acute complications (odds ratio, 0.17; 95% CI, 0.04-0.60; P = .01) and 1-year adverse aortic events (hazard ratio, 0.36; 95% CI, 0.16-0.80; P = .01)., Conclusions: We found that proximal false lumen thrombosis was a marker of reduced false lumen pressure. This might explain how proximal false lumen thrombosis appears to be protective of acute complications (eg, refractory hypertension or pain, aortic rupture, visceral or limb malperfusion, acute expansion) and adverse aortic events within the first year., (Copyright © 2021 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: COVID-19 infection results in a hypercoagulable state predisposing patients to thrombotic events. We report the 3- and 6-month follow-up of 27 patients who experienced acute arterial thrombotic events in the setting of COVID-19 infection., Methods: Data were prospectively collected and maintained for all vascular surgery consultations in the Mount Sinai Health System from patients who presented between March 16 and May 5, 2020., Results: Twenty-seven patients experienced arterial thrombotic events. The average length of stay was 13.3 ± 15.4 days. Fourteen patients were treated with open surgical intervention, six were treated with endovascular intervention, and seven were treated with anticoagulation only. At 3-month follow-up, 11 patients (40.7%) were deceased. Nine patients who expired did so during the initial hospital stay. The 3-month cumulative primary patency rate for all interventions was 72.2%, and the 3-month primary patency rates for open surgical and endovascular interventions were 66.7 and 83.3, respectively. There were 9 (33.3%) readmissions within 3 months. Six-month follow-up was available in 25 (92.6%) patients. At 6-month follow-up, 12 (48.0%) patients were deceased, and the cumulative primary patency rate was 61.9%. The 6-month primary patency rates of open surgical and endovascular interventions were 66.7% and 55.6%, respectively. The limb-salvage rate at both 3 and 6 months was 89.2%., Conclusions: Patients with COVID-19 infections who experienced thrombotic events saw high complication and mortality rates with relatively low patency rates., (Copyright © 2021 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Background: Most studies describing the outcomes after endovascular abdominal aortic aneurysm repair (EVAR) explantation have been from single, high-volume, centers. We performed a multicenter cross-Canadian study of outcomes after EVAR stent graft explantation. Our objectives were to describe the outcomes after late open conversion and EVAR graft explantation at various Canadian centers and the techniques and outcomes stratified by the indication for explant., Methods: The Canadian Vascular Surgery Research Group performed a retrospective multicenter study of all cases of EVAR graft explantation at participating centers from 2003 to 2018. Data were collected using a standardized, secure, online platform (RedCap [Research Electronic Data Capture]). Univariate statistical analysis was used to compare the techniques and outcomes stratified the indication for graft explantation., Results: Patient data from 111 EVAR explants collected from 13 participating centers were analyzed. The mean age at explantation was 74 years, the average aneurysm size was 7.5 cm, and 28% had had at least one instructions for use violation at EVAR. The average time between EVAR and explantation was 42.5 months. The most common indication for explantation was endoleak (n = 66; type Ia, 46; type Ib, 2; type II, 9; type III, 2; type V, 7), followed by infection in 20 patients; rupture in 18 patients (due to type Ia endoleak in 10 patients, type Ib in 1, type II in 1, type III in 2, and type V in 1), and graft thrombosis in 7 patients. The overall 30-day mortality was 11%, and 45% of the patients had experienced at least one major perioperative complication. Mortality was significantly greater for patients with rupture (33.3%) and those with infection (15%) compared with patients undergoing elective explantation for endoleak (4.5%; P = .003). The average center volume during the previous 15 years was 8 cases with a wide range (2-19 cases). A trend was seen toward greater mortality for patients treated at centers with fewer than eight cases compared with those with eight or more cases (19% vs 9%). However, the difference did not reach statistical significance (P = .23). Overall, 41% of patients had undergone at least one attempt at endovascular salvage before explantation, with the highest proportion among patients who had undergone EVAR explantation for endoleak (51%). Only 22% of patients with rupture had undergone an attempt at endovascular salvage before explantation., Conclusions: The performance of EVAR graft explantation has increasing in Canada. Patients who had undergone elective explantation for endoleak had lower mortality than those treated for either infection or rupture. Thus, patients with an indication for explanation should be offered surgery before symptoms or rupture has occurred. A trend was seen toward greater mortality for patients treated at centers with lower volumes., (Copyright © 2021 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: The presence of cancer increases arterial thromboembolic events, specifically myocardial infarction and stroke, before a formal diagnosis of cancer. To the best of our knowledge, this increase in thrombotic risk has not been studied in patients with lower extremity bypass grafts. In the present study, we aimed to determine the effect of occult cancer on femoropopliteal bypass patency., Methods: A retrospective review of femoropopliteal bypass procedures completed from 2001 to 2018 was performed. International Classification of Diseases, 9th and 10th revision, codes corresponding to breast, lung, prostate, colorectal, skin, brain, and hematologic cancer were used to identify patients who had had occult cancer. Occult cancer was defined as cancer diagnosed within ≤1 year after the bypass procedure. The demographics, comorbidities, bypass configuration and conduit, 1-month, 3-month, 6-month, and 1-year occlusion rates, major adverse limb events, and mortality rates were analyzed. Statistical analysis included t tests, χ 2 tests, and Cox regression analysis., Results: A total of 621 procedures in 517 patients met the inclusion criteria. Of the 621 procedures, 36 (5.8%) were classified as procedures in patients with occult cancer. The patients with occult cancer had had higher occlusion rates at 3 months (27.8% vs 8.0%; P < .001), 6 months (30.5% vs 15.1%; P < .01), and 1 year (44.4% vs 19.8%; P < .001). In Cox regression analysis for bypass thrombosis at 1 year, the only significant predictors were occult cancer (hazard ratio [HR], 2.03; P = .01), below-the-knee distal target (HR, 1.88; P < .01), and a compromised conduit (HR, 2.14; P < .001)., Conclusions: We found an increase in bypass graft thrombosis rates in patients who had undergone femoropopliteal bypass who had had occult cancer. Thrombosis of the graft within 1 year postoperatively might be a sign of occult cancer., (Copyright © 2021 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Zilver PTX polymer-free, paclitaxel-coated stents and Viabahn stent grafts are effective for the treatment of femoropopliteal lesions. The aim of this study was to compare clinical outcomes between the two devices in patients with symptomatic peripheral arterial disease in real-world settings., Methods: This multicenter, retrospective study concerned a clinical database of 445 patients with symptomatic peripheral arterial disease (Rutherford categories 1-6) who underwent either Zilver PTX or Viabahn implantation for a femoropopliteal lesion of 10 cm or longer with reference vessel diameters of 4.0 to 7.5 mm between 2012 and 2018 at five hospitals in Japan. Outcome measures were primary patency, freedom from stent thrombosis, freedom from any target lesion reintervention, limb salvage, and overall survival. After propensity score matching, these clinical outcomes were compared between patients treated with the Zilver PTX and those treated with the Viabahn. Also assessed were the interaction effects of baseline characteristics on the association of the Zilver PTX and Viabahn with restenosis and stent thrombosis., Results: In total, 271 patients were treated with the Zilver PTX, and 174 patients were treated with the Viabahn. Propensity score matching extracted 133 patient pairs with no major intergroup differences in baseline characteristics. The Zilver PTX group had a lower rate of 3-year primary patency (59.5%; [95% confidence interval (CI), 53.0%-66.2%] vs 69.6% [95% CI, 59.3%-79.4%]; P = .005), but a higher rate of 3-year freedom from stent thrombosis (93.6% [95% CI, 90.0%-96.3%] vs 82.4% [95% CI, 74.5%-89.0%], P = .038). There was no significant difference in overall survival, limb salvage, or freedom from reintervention (all P > .05). An interaction analysis showed that the restenosis risk of the Zilver PTX was significantly higher vs the Viabahn in patients with no or one below-the-knee runoff vessel and in those with intravascular ultrasound use than in patients with two or three below-the-knee runoff vessels and in those without intravascular ultrasound use, respectively (P for interaction = .046 and .010, respectively), whereas the stent thrombosis risk of the Zilver PTX was significantly smaller vs the Viabahn in patients not on dialysis than in those on dialysis (P for interaction = .034)., Conclusions: Compared with Viabahn stent grafts, Zilver PTX stents have a lower rate of primary patency but a higher rate of freedom from stent thrombosis., (Copyright © 2020 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Background: Little is known about the arterial complications and hypercoagulability associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We sought to characterize our experience with arterial thromboembolic complications in patients with hospitalized for coronavirus disease 2019 (COVID-19)., Methods: All patients admitted from March 1 to April 20, 2020, and who underwent carotid, upper, lower and aortoiliac arterial duplex, computed tomography angiogram or magnetic resonance angiography for suspected arterial thrombosis were included. A retrospective case control study design was used to identify, characterize and evaluate potential risk factors for arterial thromboembolic disease in SARS-CoV-2 positive patients. Demographics, characteristics, and laboratory values were abstracted and analyzed., Results: During the study period, 424 patients underwent 499 arterial duplex, computed tomography angiogram, or magnetic resonance angiography imaging studies with an overall 9.4% positive rate for arterial thromboembolism. Of the 40 patients with arterial thromboembolism, 25 (62.5%) were SARS-CoV-2 negative or admitted for unrelated reasons and 15 (37.5%) were SARS-CoV-2 positive. The odds ratio for arterial thrombosis in COVID-19 was 3.37 (95% confidence interval, 1.68-6.78; P = .001). Although not statistically significant, in patients with arterial thromboembolism, patients who were SARS-CoV-2 positive compared with those testing negative or not tested tended to be male (66.7% vs 40.0%; P = .191), have a less frequent history of former or active smoking (42.9% vs 68.0%; P = .233) and have a higher white blood cell count (14.5 vs 9.9; P = .208). Although the SARS-CoV-2 positive patients trended toward a higher the neutrophil-to-lymphocyte ratio (8.9 vs 4.1; P = .134), creatinine phosphokinase level (359.0 vs 144.5; P = .667), C-reactive protein level (24.2 vs 13.8; P = .627), lactate dehydrogenase level (576.5 vs 338.0; P = .313), and ferritin level (974.0 vs 412.0; P = .47), these differences did not reach statistical significance. Patients with arterial thromboembolic complications and SARS-CoV-2 positive when compared with SARS-CoV-2 negative or admitted for unrelated reasons were younger (64 vs 70 years; P = .027), had a significantly higher body mass index (32.6 vs 25.5; P = .012), a higher d-dimer at the time of imaging (17.3 vs 1.8; P = .038), a higher average in hospital d-dimer (8.5 vs 2.0; P = .038), a greater distribution of patients with clot in the aortoiliac location (5 vs 1; P = .040), less prior use of any antiplatelet medication (21.4% vs 62.5%; P = .035), and a higher mortality rate (40.0% vs 8.0%; P = .041). Treatment of arterial thromboembolic disease in COVID-19 positive patients included open thromboembolectomy in six patients (40%), anticoagulation alone in four (26.7%), and five (33.3%) did not require or their overall illness severity precluded additional treatment., Conclusions: Patients with SARS-CoV-2 are at risk for acute arterial thromboembolic complications despite a lack of conventional risk factors. A hyperinflammatory state may be responsible for this phenomenon with a preponderance for aortoiliac involvement. These findings provide an early characterization of arterial thromboembolic disease in SARS-CoV-2 patients., (Copyright © 2020 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Widespread adoption of direct oral anticoagulants (DOACs) for atrial fibrillation and venous thromboembolism treatment has resulted in peripheral bypass patients receiving therapeutic anticoagulation with DOACs postoperatively. This study was undertaken to evaluate patient outcomes after open peripheral bypass based on anticoagulation treatment., Methods: Postoperative treatment and outcomes of patients undergoing peripheral bypass operations between January 2012 and December 2017 from a statewide multicenter quality improvement registry were examined. Surgeons participating in the registry were surveyed on practice patterns regarding DOACs in bypass patients. Multivariate logistic regression was performed for 30-day transfusion outcomes, and multiple linear regression was performed for length of stay., Results: Among 9682 patients, 7685 patients received no anticoagulation, whereas 1379 received a vitamin K antagonist (VKA) and 618 received a DOAC postoperatively. Patients receiving anticoagulation compared with no anticoagulation had a higher body mass index and were more likely to have preoperative anemia, congestive heart failure, and atrial fibrillation (all P < .001). Compared with patients receiving VKAs, patients receiving DOACs were less likely to have chronic kidney disease (P = .002) and more likely to have atrial fibrillation (P < .001). The shortest length of stay was among patients receiving no anticoagulation (median, 5 days; interquartile range, 3-9 days; P < .001), followed by DOACs (median, 6 days; interquartile range 3-11 days; P < .001) and VKAs (median, 8 days; interquartile range, 5-13 days; P < .001). Compared with patients receiving VKAs postoperatively, there was no difference in readmission for anticoagulation complications, bypass thrombectomy or thrombolysis, major amputation, or graft patency at 1 year among patients receiving DOACs. On multivariate logistic regression, patients receiving a DOAC (odds ratio, 0.743; confidence interval, 0.59-0.94; P = .011) or no anticoagulation (odds ratio, 0.792; confidence interval, 0.69-0.91; P = .001) were less likely to require transfusion within 30 days than patients taking VKAs. Approximately 70% of the surveyed surgeons reported that they "sometimes" or "always" use DOACs instead of VKAs for protection of a high-risk bypass., Conclusions: Among patients undergoing lower extremity surgical bypass, those receiving a DOAC postoperatively had a shorter length of stay and were less likely to receive a transfusion in 30 days without compromising graft patency and readmission for anticoagulation complications, thrombectomy, or thrombolysis or affecting amputation rate compared with those receiving a VKA. A majority of surgeons within the quality collaborative have adopted the use of DOACs after peripheral bypass, suggesting the need for a prospective trial evaluating DOAC safety and efficacy in patients requiring anticoagulation for high-risk bypass grafts., (Copyright © 2020 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Arterial involvement in Behçet disease (BD) is rare, and its surgical management is a major concern because of its high recurrence rate. This study evaluated the influence of the surgical technique, device, and immunosuppressive treatment used on the postoperative recurrence in patients with non-pulmonary arterial BD., Methods: A single-center, retrospective study was conducted of 23 patients meeting the international criteria for BD who underwent surgery for arterial involvement between May 1996 and September 2015. Recurrence was defined as the occurrence of arterial aneurysm or thrombosis during follow-up. Perioperative medical treatment and surgical technique used were reported., Results: There were 47 surgical procedures performed in 23 patients. Mean follow-up was 8.4 ± 7.5 years. Initial arterial lesions were aneurysms and thrombosis in 85% and 15% of cases, respectively. Arterial lesions were aortic and peripheral in 48% and 52% of cases. Recurrence rate was 51%. Recurrences developed within <1 year in 24% of cases and at the same anatomic site in 92% of cases. Among the 24 recurrences, 17 were false aneurysms, 6 were thrombosis, and 1 was a true aneurysm in a different arterial site. To treat the arterial lesion, direct anastomosis was performed in 6 cases; bypass using the saphenous vein, graft, or allograft was performed in 6, 27, and 5 cases, respectively; and stent graft was used in 3 cases. Vascular lesions involved the aorta in 19 cases and a peripheral artery in 28 cases. Preoperative medical treatments, including colchicine, steroids, and immunosuppressants, significantly decreased recurrence rate: 28% (7/25) vs 75% (15/20) in untreated patients (P = .002). The recurrence rate was 42.5% (17/40) in patients treated postoperatively vs 80% (4/5) in untreated patients. The nature of the device used (vein, prosthetic graft, allograft, stent graft, or direct anastomosis) did not change the risk of recurrence. When anastomoses were protected using the prosthetic sleeving technique, the recurrence rate was three times lower (P = .08)., Conclusions: Relapse is a main concern after surgical repair of arterial BD. This study suggests the need for targeted perioperative medical management to reduce the risk of arterial recurrence in BD patients. To this end, a multidisciplinary approach is mandatory. The use of sleeve anastomosis is associated with a numerically lower risk of recurrence. However, further studies are needed to confirm this efficacy., (Copyright © 2020 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: The objective of this study was to determine the influence of hemodynamic force on the development of type III endoleak and branch thrombosis after complex endovascular thoracoabdominal aortic aneurysm repair., Methods: Patients with thoracoabdominal aortic aneurysm, within surgical range, treated with a fenestrated or branched endovascular aneurysm repair from 2014 to 2018 and with 3-month control computed tomography angiography were selected. Demographic variables, aneurysm anatomy, and endograft conformation were analyzed retrospectively from a prospective registry. The hemodynamic force was calculated using the mass and momentum conservation equations., Results: Twenty-eight patients were included; the mean follow-up period was 24.7 ± 19.3 months. There were 102 abdominal vessels successfully catheterized (19 celiac arteries, 29 superior mesenteric arteries, 27 right renal arteries, 26 left renal arteries, and 1 polar renal artery). The rate of type III endoleak was 11.5% (n = 12); six cases were associated with branches that received two stents (P < .001). A higher rate of endoleak was observed with wider stents (8.50 ± 1.0 mm vs 7.17 ± 1.3 mm; P = .001) but not with longer stents (P = .530). All cases of type III endoleak affected visceral arteries (eight celiac arteries and four superior mesenteric arteries). The freedom from type III endoleak at 24 months was 86%. The rate of thrombosis was 5.9% (n = 6). A higher rate of thrombosis was observed in smaller vessels (5.00 ± 1.3 mm vs 7.16 ± 1.8 mm; P = .001), with higher stent oversizing (36.87% ± 23.6% vs 5.52% ± 15.0%; P < .001), and with a higher angle of curvature (124.33 ± 86.1 degrees vs 57.71 ± 27.9 degrees; P < .001). All cases of thrombosis were related to renal arteries (two left renal arteries, two right renal arteries, and two polar renal arteries). The freedom from thrombosis at 24 months was 92%. The area under the curve for the angle of curvature was 0.802 (95% confidence interval, 0.661-0.943; P = .013), and the cutoff point was established at 59.5 degrees (sensitivity, 100%; specificity, 60.4%). The receiver operating characteristic curve for the stent oversize showed an area under the curve of 0.903 (95% confidence interval, 0.821-0.984; P = .001), and the cutoff point was 14.5% (sensitivity, 100%; specificity, 77.1%). A higher hemodynamic force was associated with thrombosis (23.35 × 10 -3  N ± 18.7 × 10 -3  N vs 12.31 × 10 -3  N ± 6.8 × 10 -3  N; P = .001) but not with endoleak (P = .796). The freedom from endoleak and thrombosis at 24 months was 86% and 90%, respectively., Conclusions: Longer stents should be preferred to avoid type III endoleak. A higher angle of curvature leads to a higher hemodynamic force that results in a higher rate of thrombosis. Accordingly, we recommend maintaining the angle of curvature under 59.9 degrees. Small vessels and excessive stent oversizing entail a higher risk of thrombosis; as such, we advise a maximum stent oversize of 14.5%. Renal arteries are more susceptible to thrombosis, whereas visceral arteries are more prone to endoleak., (Copyright © 2020 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: The objective of this study was to assess the technical and short- and long-term clinical outcomes of catheter-directed thrombolysis (CDT) with urokinase for occluded infrainguinal bypass grafts. In addition, factors associated with technical success and amputation-free survival were assessed., Methods: A retrospective analysis of a cohort of patients treated with catheter-directed urokinase-based thrombolysis for occluded infrainguinal bypass grafts was conducted between January 2000 and December 2015. Demographics, procedural data, and short- and long-term outcome data, including patency rates of the bypasses, limb salvage, and overall survival, were collected. Statistical models for clustered data were applied to assess predictive factors., Results: In 177 patients, 251 CDTs were performed on 204 bypasses. In 209 procedures (83.3%), the occluded bypass was reopened; clinical disappearance of ischemic symptoms occurred after 157 procedures (62.6%). Premature cessation of thrombolysis occurred in 33 procedures (13.2%), and periprocedural and postprocedural complications were noted in 91 patients (36.3%). Factors associated with long-term limb salvage are fewer vascular interventions before CDT (P = .0003), higher number of patent outflow vessels before start of CDT (P < .0001), and higher number of patent outflow vessels after CDT (P < .0001). The 1- and 5-year patency rates of bypasses after successful CDT were 64.6% and 48.9%; amputation-free survival after 1 year, 5 years, and 7 years was 81.5%, 71.3%, and 70.5%, respectively., Conclusions: Clinical success after CDT was observed in 62% of procedures with an associated complication rate of 36%. Patent outflow vessels before and after CDT are factors associated with long-term limb salvage. Amputation-free survival after 5 years is 71.3%., (Copyright © 2019 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: The factors associated with access site failure after ultrasound-guided percutaneous access for aortic endograft procedures remain poorly characterized. We developed a prediction model to risk stratify patients for access site failure., Methods: We performed a retrospective institutional review of consecutive patients who underwent endovascular aneurysm repair (EVAR), fenestrated EVAR (FEVAR), or thoracic endovascular aortic repair (TEVAR) from 2014 to 2016. We excluded patients undergoing direct aortic access through sternotomy and patients treated with physician-modified endografts, given reporting restrictions. Our primary outcome was groin access site failure, which included bleeding and thrombosis. An 8-point risk model was created for access site failure using multivariable fractional polynomials and internally validated using bootstrapping., Results: We identified 469 femoral arteries from 247 patients undergoing endovascular aortic repair procedures (EVAR, 75%; FEVAR, 8.0%; TEVAR, 17%). Surgeons performed percutaneous access in 97.2% of the femoral arteries, with 99.6% ultrasound use. Twenty-seven (5.9%) access site failures occurred (17 bleeding, 10 thrombosis), all treated with groin cutdown, for a successful percutaneous femoral artery access rate of 94%. Of the 215 patients with attempted bilateral percutaneous access, 90% had successful bilateral access. However, FEVAR had lower rates of successful bilateral access (FEVAR, 78%; EVAR, 91%; TEVAR, 94%; P = .03). Factors independently associated with percutaneous access site failure were femoral artery outer wall diameter (per millimeter increase: odds ratio [OR], 0.003 [0.0002-0.1]; P < .001), femoral artery stenosis >50% (OR, 22.3 [2.7-183.2]; P < .01), and urgent/emergent intervention (OR, 3.6 [1.2-11.0]; P = .03). A risk prediction model based on these criteria produced a C statistic of 0.89, a Hosmer-Lemeshow goodness of fit of 0.99, and a Brier score of 0.04. Excluding treatment for ruptured aneurysms, cutdown for access failure and planned initial groin cutdown resulted in longer postoperative lengths of stay and higher rates of access-related readmission, return to operating room, groin infection, and myocardial infarction compared with successful percutaneous access. There was no difference in major adverse events between planned initial groin cutdown and cutdown after failure; however, the small number of patients in these two comparison groups limits the statistical power to detect a difference., Conclusions: Percutaneous ultrasound-guided access can be safely performed in almost all patients undergoing endovascular aortic procedures, but access site failures do occur. This risk score can help users select patients with high likelihood of success, identify patients who need close scrutiny with postclosure femoral duplex ultrasound, and provide patient guidance about risk of unplanned groin cutdown., (Copyright © 2019 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Arteriovenous fistulas created in patients with chronic kidney disease often lose patency and fail to become usable. This prospective trial evaluated the efficacy of vonapanitase, a recombinant human elastase, in promoting radiocephalic fistula patency and use for hemodialysis., Methods: PATENCY-1 was a double-blind, placebo-controlled trial that enrolled 349 patients on or approaching hemodialysis and being evaluated for radiocephalic arteriovenous fistula creation. Of these, 313 were randomized and 311 treated. Patients were assigned to vonapanitase (n = 210) or placebo (n = 103). The study drug solution was applied topically to the artery and vein for 10 minutes immediately after fistula creation. The primary and secondary end points were primary patency (time to first thrombosis or corrective procedure) and secondary patency (time to abandonment). Tertiary end points included use of the fistula for hemodialysis, fistula maturation by ultrasound, and procedure rates., Results: The Kaplan-Meier estimates of 12-month primary patency were 42% (95% confidence interval [CI], 35-49) and 31% (95% CI, 21-42) for vonapanitase and placebo (P = .25). The Kaplan-Meier estimates of 12-month secondary patency were 74% (95% CI, 68-80) and 61% (95% CI, 51-71) for vonapanitase and placebo (P = .048). The proportions of vonapanitase and placebo patients were 39% and 25% (P = .035) with unassisted use for hemodialysis and 64% and 44% (P = .006) with unassisted plus assisted use., Conclusions: Vonapanitase treatment did not significantly improve primary patency but was associated with increased secondary patency and use for hemodialysis. Further research is needed to evaluate these end points., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: We report midterm outcomes with the GORE Iliac Branch Endoprosthesis (IBE; W. L. Gore & Associates, Flagstaff, Ariz) in the U.S. investigational device exemption (IDE) trial and comparatively assess outcomes in the IDE trial with outcomes in a real-world population of patients treated in the Gore Global Registry for Endovascular Aortic Treatment (GREAT)., Methods: From 2013 to 2016, the IDE trial enrolled 99 patients treated with the IBE for common iliac artery (CIA) aneurysms or aortoiliac aneurysms. Bilateral IBE treatment was allowed only in the continued access phase. From 2013 to 2016, there were 92 patients treated with the IBE in the GREAT registry. Baseline characteristics, procedural variables, and reinterventions through 6 months were compared in the IDE trial and GREAT registry. Clinical and core laboratory-assessed imaging outcomes were assessed in the IDE trial through 2 years., Results: GREAT patients were significantly older (P = .01) and of shorter height (P < .001) and lower weight (P < .001). There were also significantly more women treated in GREAT vs the IDE trial (8% vs 1%; P = .02). Thirteen GREAT patients (14%) and 4 of 35 continued access IDE patients (11%) had bilateral IBE placement (P = .70). IDE patients were more likely to be treated with percutaneous access methods (55% vs 40%; P = .04). Three IDE patients and three GREAT patients underwent 1-month reintervention, with two IDE reinterventions (2.1%) and one GREAT reintervention (1.6%) for thrombotic events. Five additional patients in each study underwent reintervention through 6 months (5% vs 5%; P = .92), all for nonthrombotic events. Internal iliac limb patency was 93.6% (95% confidence interval, 86.4%-97.1%) at 12 and 24 months in the IDE study. Subset analyses of the 10 IDE and GREAT patients with ≤6-month reintervention vs 181 intervention-free patients found that acute myocardial infarction (P = .01), nonpercutaneous access (P = .01), and surgical conduit use (P < .001) were associated with reintervention through 6 months. In the IDE trial, 3.4% and 4.1% of patients underwent reintervention at 12 months and 24 months, respectively, all for treatment of type II endoleaks. At 24 months, 8.7% of IDE patients exhibited abdominal aortic aneurysm sac expansion; 21.7% exhibited abdominal aortic aneurysm sac regression. No patients exhibited CIA aneurysm sac expansion; 45% exhibited CIA aneurysm sac regression., Conclusions: Midterm IDE outcomes and 6-month outcomes in the worldwide GREAT registry suggest that endovascular aortic aneurysm repair with concomitant CIA aneurysm repair with the IBE device is safe and effective. Thrombotic events are uncommon and are concentrated in the first month after the index procedure, and they typically can be resolved with endovascular reintervention., (Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: For patients with end-stage renal disease on hemodialysis, the durability of vascular access (VA) is still far from optimal, and access survival after intervention for access failure is an important aspect. Procoagulant status is a leading cause of access failure. Coagulation-fibrinolysis imbalance can occur in hemodialyzed patients, but the influence of the imbalance has not been fully elucidated., Methods: We prospectively examined coagulation-fibrinolysis balance to assess the risk of access failure after the intervention of revascularization in a cohort of 462 hemodialysis patients. Thrombin-antithrombin complex (TAT) and plasmin-α 2 -plasmin inhibitor complex (PIC) are markers for coagulation and fibrinolysis. Median follow-up was 243 days. The end point was clinical access failure: revascularization or access revision. The survival curve for VA patency was assessed using the Kaplan-Meier method and compared using the log-rank test. Cox proportional hazards regression models that allowed adjustment for baseline differences in age, sex, dialysis vintage, diabetes mellitus, and various factors (quantity of blood flow, prothrombin time-international normalized ratio, fibrin degradation products, C-reactive protein, interleukin-6, tumor necrosis factor-α, and pentraxin-3) were used., Results: The 162 patients who reached an end point had smaller access flow volume and smaller percentage of arteriovenous fistula and higher TAT/PIC ratio. Kaplan-Meier analysis indicated that the patients with elevated TAT/PIC ratio showed poorer outcome (P < .001). On Cox regression modeling, elevated TAT/PIC was an independent risk factor for access failure (hazard ratio, 1.58; P = .03)., Conclusions: Our results suggest that coagulation-fibrinolysis imbalance is a significant risk factor for access failure and may predict VA failure in hemodialyzed patients after access intervention., (Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objectives: Catheter-related right atrial thrombosis (CRAT) is an underreported but potentially life-threatening complication associated with the use of tunneled-cuffed catheters among hemodialysis (HD) patients. Because little is known about the evidence-based guidelines for the optimal management of CRAT among HD patients, this article reports findings based on 20 patients diagnosed with CRAT after catheter replacement and anticoagulation treatment., Methods: The article retrospectively reviews the hospital records of 20 HD patients treated in the West China Hospital with diagnosis of CRAT from March 2013 to May 2016. Once CRAT was diagnosed, tunneled-cuffed catheters were exchanged over a guidewire in situ and the locations of the new catheter tips were adjusted to be away from the original sites. Immediately after the insertion of a new tunneled-cuffed catheter and at the end of each HD session, both ports of the catheters were locked with unfractionated heparin solution. Patients younger than 70 years of age were treated with warfarin at a target International Normalized Ratio of 1.5 to 1.9, whereas those older than 70 years were treated with dual antiplatelet therapy. All patients were on regular dialysis without thrombolysis or thrombectomy., Results: During the follow-up, two patients died of gastrointestinal massive hemorrhage and one died of acute myocardial infarction. No fatal pulmonary embolism or other CRAT complication-related deaths were observed. A total of eight patients had complete dissolution of CRAT, and 12 patients had reduction in thrombi size., Conclusions: Maintenance of HD by replacing catheters and providing oral anticoagulation/antiplatelet therapies may be an effective strategy for treating HD patients with CRAT., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: Optimal treatment of spontaneous isolated celiac artery dissection (SICAD) is not well established because the natural history of this rare disease is poorly understood. We analyzed the natural history of patients who underwent conservative treatment., Methods: The study included 28 patients with SICAD from December 2008 to January 2017. Our institutional policy of first-line treatment for SICAD patients was conservative, and invasive procedures were reserved for unstable complications such as severe persistent pain, significant organ malperfusion, rapid aneurysmal change, and rupture or concealed rupture. Demographics, clinical features, morphologic characteristics on computed tomography, treatment modalities, and follow-up results of these patients were retrospectively reviewed., Results: Mean age was 52 years, and 89% of patients were male; 86% presented with pain, mostly abdominal, and 14% of cases were detected incidentally on abdominal imaging. None of these patients had unstable complications on admission, and all underwent initial conservative treatment. During the follow-up period (22 ± 20 months), aneurysmal change and propagation of thrombosis were noted in one patient and two patients, respectively, all of whom were managed conservatively without adverse clinical events. No difference in clinical and morphologic outcomes was noted between patients who were treated with antihypertensive therapy and those who were not. Patients with intramural hematoma on initial images showed dynamic vascular remodeling (partial to complete resorption) during the follow-up period compared with patients who had dominant intimal flap on initial images., Conclusions: The clinical course of patients with SICAD was benign. Even progressive vascular changes during follow-up did not require invasive treatment. Antihypertensive therapy might not modify the clinical course. The short-term results of conservative management are encouraging, but further evaluation with long-term follow-up in a large population is needed., (Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Arteriovenous (AV) fistulas are the preferred hemodialysis access for patients with end-stage renal disease, although multiple interventions are typically needed to maintain patency. When AV fistulas thrombose, however, there is debate as to whether open thrombectomy should be attempted, particularly for salvage of upper arm fistulas. This study was designed to evaluate outcomes after open thrombectomy of upper arm and forearm AV fistulas compared with AV grafts., Methods: We identified all patients who underwent an open thrombectomy procedure for a thrombosed AV fistula or graft at a single academic medical center between January 2006 and March 2017. The specific type of AV fistula or graft was evaluated, as were the patients' demographics, comorbidities, medications, adjunctive procedures during thrombectomy, and secondary interventions. The primary outcome measures, postintervention primary patency and postintervention secondary patency, were analyzed using Kaplan-Meier curves and Cox regression models for risk adjustment., Results: During the study period, 209 open thrombectomy procedures were performed in 139 patients; 73 (35%) were undertaken in AV fistulas and 136 (65%) in grafts. Patients with upper arm fistulas (n = 52; 54% brachiocephalic, 46% brachiobasilic) and forearm fistulas (n = 16) were more likely to be male but less likely to have cerebrovascular disease or ischemic heart disease and to be receiving anticoagulation therapy compared with graft patients. After thrombectomy, the majority of patients underwent dialysis successfully (70% upper arm fistulas, 56% forearm fistulas, 63% grafts; P > .05), and 1-year survival rates were similar in all three cohorts. Postintervention primary patency at 1 year was significantly higher for AV fistulas vs grafts (33% for upper arm fistulas and 25% for forearm fistulas vs 9% for grafts; P < .05), which was confirmed in multivariate analysis, where upper arm AV fistulas had a 46% lower risk of recurrent thrombosis or secondary intervention (hazard ratio, 0.56; 95% confidence interval, 0.35-0.85; P < .05). Postintervention secondary patency at 1 year was similar between AV fistulas and grafts (44% for upper arm fistulas vs 43% for forearm fistulas vs 31% for grafts; P = .16), but in multivariate analysis, upper arm fistulas were significantly less likely to fail (hazard ratio, 0.63; 95% confidence interval, 0.40-1.00; P = .05)., Conclusions: Our data suggest that AV fistula thrombectomy is successful in up to 70% of cases, with significantly improved risk-adjusted 1-year primary and secondary patency rates for upper arm fistulas compared with grafts. Whereas the risk of access failure is high after thrombectomy, efforts to salvage upper arm AV fistulas are effective in most patients and should be undertaken when feasible., (Copyright © 2018 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: The urgency with which salvage of thrombosed vascular accesses for dialysis should be attempted remains unknown. We examined the effect of a timely thrombectomy approach on vascular access outcomes for dialysis., Methods: A before-and-after study was conducted with patients on hemodialysis who had undergone endovascular thrombectomy. A timely thrombectomy initiative (ie, salvage within 24 hours of thrombosis diagnosis) was started in July 2015 at our institution. Data about thrombectomy procedures, performed within 1 year before and after the initiative was introduced, were abstracted from an electronic database. Immediate outcomes and patency outcomes were compared between the preinitiative (control) and postinitiative (intervention) groups., Results: During the study period, 329 patients were enrolled, including 165 cases before and 164 cases after the initiative. The intervention group had more thrombectomy procedures performed within 24 hours (93% vs 55%; P < .01) and within 48 hours (97% vs 79%; P < .01) than the control group. No between-group differences in procedural success or clinical success rates were found. At 3 months, the intervention group had a higher postintervention primary patency rate than the control group, although this did not reach statistical significance (58% vs 48%; P = .06). After stratification into native or graft accesses, the patency benefit was observed in the native access group (68% vs 50%; P = .03) but not in the graft access group (50% vs 46%; P = .65). After adjusting for potential confounders, timely thrombectomy remained an independent predictor of postintervention primary patency (hazard ratio, 0.449; 95% confidence interval, 0.224-0.900; P = .02) for native dialysis accesses., Conclusions: Our results suggest that a timely thrombectomy approach, in which salvage is attempted within 24 hours of thrombosis diagnosis, improves postintervention primary patency of native but not graft accesses for dialysis., (Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Background: The implications of intraluminal thrombus (ILT) in abdominal aortic aneurysm (AAA) are currently unclear. Previous studies have demonstrated that ILT provides a biomechanical advantage by decreasing wall stress, whereas other studies have associated ILT with aortic wall weakening. It is further unclear why some aneurysms rupture at much smaller diameters than others. In this study, we sought to explore the association between ILT and risk of AAA rupture, particularly in small aneurysms., Methods: Patients were retrospectively identified and categorized by maximum aneurysm diameter and rupture status: small (<60 mm) or large (≥60 mm) and ruptured (rAAA) or nonruptured (non-rAAA). Three-dimensional AAA anatomy was digitally reconstructed from computed tomography angiograms for each patient. Finite element analysis was then performed to calculate peak wall stress (PWS) and mean wall stress (MWS) using the patient's systolic blood pressure. AAA geometric properties, including normalized ILT thickness (mean ILT thickness/maximum diameter) and % volume (100 × ILT volume/total AAA volume), were also quantified., Results: Patients with small rAAAs had PWS of 123 ± 51 kPa, which was significantly lower than that of patients with large rAAAs (242 ± 130 kPa; P = .04), small non-rAAAs (204 ± 60 kPa; P < .01), and large non-rAAAs (270 ± 106 kPa; P < .01). Patients with small rAAAs also had lower MWS (44 ± 14 kPa vs 82 ± 20 kPa; P < .02) compared with patients with large non-rAAAs. ILT % volume and normalized ILT thickness were greater in small rAAAs (68% ± 11%; 0.16 ± 0.04 mm) compared with small non-rAAAs (53% ± 16% [P = .02]; 0.11 ± 0.04 mm [P < .01]) and large non-rAAAs (57% ± 12% [P = .02]; 0.12 ± 0.03 mm [P < .01]). Increased ILT % volume was associated with both decreased MWS and decreased PWS., Conclusions: This study found that although increased ILT is associated with lower MWS and PWS, it is also associated with aneurysm rupture at smaller diameters and lower stress. Therefore, the protective biomechanical advantage that ILT provides by lowering wall stress seems to be outweighed by weakening of the AAA wall, particularly in patients with small rAAAs. This study suggests that high ILT burden may be a surrogate marker of decreased aortic wall strength and a characteristic of high-risk small aneurysms., (Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: The purpose of the study was to aggressively salvage acutely occluded arteriovenous fistulas (AVFs) using duplex imaging as the sole imaging modality for percutaneous transluminal angioplasty of acutely thrombosed AVF., Methods: Over a period of 12 months, 14 patients with acute thrombosis of their AVFs underwent 18 procedures in a single center for AVF salvage. All 14 patients presented with chronic renal failure, and six were diabetic. All patients were treated under duplex guidance alone. Treatment included simple balloon dilation and maceration (group A; n =10 procedures [56%]) for subacute thrombosis or pharmacomechanical thrombectomy (group B; n = 8 procedures [44%]) for more hypoechoic thrombus. A successful procedure was defined as immediate restoration of flow through the AVF., Results: Of the 18 procedures, 13 (72%) were successful. Of the 14 patients, thrombus was located at the perianastomotic AVF in 6 (43%), proximal-mid AVF in 6 (43%), mid AVF in 1 (7%), and distal AVF in 1 (7%). From group A, six (60%) were successful. From group B, seven (88%) were successful. Among the unsuccessful procedures, one group B patient was hypercoagulable (polycythemia vera). Of the 18 procedures, 16 (89%) were treated within 2 weeks from when duplex revealed the presence of thrombus. Early rethrombosis (<1-month patency) occurred in three cases (17%), and these patients received new fistulas. Full restoration of the fistula flow was established in 14 cases (78%). Of these 14 patients, 8 (57%) are currently on hemodialysis via fistula, 3 patients (21%) had newly placed fistulas after failed interventions, 2 patients (14%) are not on dialysis yet, and 1 patient (7%) with polycythemia vera disorder is on dialysis via a Tesio catheter (MedComp, Harleysville, Pa)., Conclusions: The sole use of duplex ultrasound imaging to salvage acutely occluded AVFs using percutaneous transluminal angioplasty is a safe and effective alternative to traditional treatment of thrombosed failing/maturing AVF., (Published by Elsevier Inc.)

Background: Arteriovenous grafts made of polyurethane (PU) have the advantage of early cannulation obviating the placement of a central vein catheter in patients with an acute need for long-term hemodialysis. The aim of the present study was to evaluate the safety, efficacy and complication rate of PU vascular grafts for dialysis access in patients in whom early cannulation was performed., Methods: Between January 2007 and December 2015, 125 straight brachial-axillary grafts were placed in patients with an acute thrombosis of a previous arteriovenous access. Sixty-four were PU and 61 were polytetrafluoroethylene (PTFE) grafts. Patency and complications rates were compared between the two groups., Results: The median interval from implantation to cannulation was 1 day in the PU group vs 28 days in the PTFE group. Cumulative infection rate at 5 years was 13% and 8% in the PU and the PTFE groups, respectively (P = .6). None of the patients in the PU group developed a pseudoaneurysm necessitating intervention, compared with one patient in the PTFE group. Primary and secondary patency rates did not differ significantly between the two groups. The cumulative median primary patency was 23 months in the PU group vs 26 months in the PTFE group. Median secondary patency was 42 vs 33 months, respectively. Diabetes mellitus was the only factor adversely affecting graft patency in both groups., Conclusions: PU grafts offer the advantage of early cannulation with infection, pseudoaneurysm formation and patency rates similar to those of the PTFE grafts., (Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Background: The chimney technique has been successfully used to treat juxtarenal aortic aneurysms. The two main issues with this technique are gutter formation and chimney graft (CG) compression, which induce a risk for type Ia endoleaks and stent thrombosis, respectively. In this benchtop study, the geometry and renal artery flow of chimney endovascular aneurysm repair configurations were compared with chimney configurations with endovascular aneurysm sealing (ch-EVAS)., Methods: Seven flow phantoms were constructed, including one control and six chimney endovascular aneurysm repairs (Endurant [Medtronic Inc, Minneapolis, Minn] and AFX [Endologix Inc, Irvine, Calif]) or ch-EVAS (Nellix, Endologix) configurations, combined with either balloon-expandable or self-expanding CGs with an intended higher positioning of the right CG in comparison to the left CG. Geometric analysis was based on measurements at three-dimensional computed tomography angiography and included gutter volume and CG compression, quantified by the ratio between maximal and minimal diameter (D-ratio). In addition, renal artery flow was studied in a physiologic flow model and compared with the control., Results: The average gutter volume was 343.5 ± 142.0 mm 3 , with the lowest gutter volume in the EVAS-Viabahn (W. L. Gore & Associates, Flagstaff, Ariz) combination (102.6 mm 3 ) and the largest in the AFX-Advanta V12 (Atrium Medical Corporation, Hudson, NH) configuration (559.6 mm 3 ). The maximum D-ratio was larger in self-expanding CGs than in balloon-expandable CGs in all configurations (2.02 ± 0.34 vs 1.39 ± 0.13). The CG compression had minimal influence on renal volumetric flow (right, 390.7 ± 29.4 mL/min vs 455.1 mL/min; left, 423.9 ± 28.3 mL/min vs 410.0 mL/min in the control)., Conclusions: This study showed that gutter volume was lowest in ch-EVAS in combination with a Viabahn CG. CG compression was lower in configurations with the Advanta V12 than with Viabahn. Renal flow is unrestricted by CG compression., (Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Isolated dissection of the mesenteric vessels is rare but increasingly recognized. This study aimed to evaluate patient characteristics, primary treatment, and subsequent outcomes of mesenteric dissection using multi-institutional data., Methods: All patients at participant hospitals between January 2003 and December 2015 with dissection of the celiac artery (or its branches) or dissection of the superior mesenteric artery (SMA) were included. Patients with an aortic dissection were excluded. Demographic, treatment, and follow-up data were collected. The primary outcomes included late vessel thrombosis (LVT) and aneurysmal degeneration (AD)., Results: Twelve institutions identified 227 patients (220 with complete treatment records) with a mean age of 55 ± 12.5 years. Median time to last follow up was 15 months (interquartile range, 3.8-32). Most patients were men (82% vs 18% women) and symptomatic at presentation (162 vs 65 asymptomatic). Isolated SMA dissection was more common than celiac artery dissection (n = 158 and 81, respectively). Concomitant dissection of both arteries was rare (n = 12). The mean dissection length was significantly longer in symptomatic patients than in asymptomatic patients in both the celiac artery (27 vs 18 mm; P = .01) and the SMA (64 vs 40 mm; P < .001). Primary treatment was medical in 146 patients with oral anticoagulation or antiplatelet therapy (n = 76 and 70, respectively), whereas 56 patients were observed. LVT occurred in six patients, and 16 patients developed AD (3% and 8%, respectively). For symptomatic patients without evidence of ischemia (n = 134), there was no difference in occurrence of LVT with medical therapy compared with observation alone (9% vs 0%; P = .35). No asymptomatic patient (n = 64) had an episode of LVT at 5 years. AD rates did not differ among symptomatic patients without ischemia treated with medical therapy or observed (9% vs 5%; P = .95). Surgical or endovascular intervention was performed in 18 patients (3 ischemia, 13 pain, 1 AD, 1 asymptomatic). Excluding the patients treated for ischemia, there was no difference in LVT with surgical intervention vs medical management (one vs five; P = .57)., Conclusions: Asymptomatic patients with isolated mesenteric artery dissection may be observed and followed up with intermittent imaging. Symptomatic patients tend to have longer dissections than asymptomatic patients. Symptomatic isolated mesenteric artery dissection without evidence of ischemia does not require anticoagulation and may be treated with antiplatelet therapy or observation alone., (Copyright © 2017 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Background: The high-risk patient cohort of uncomplicated type B aortic dissections (uTBADs) needs to be clarified. We compared uTBAD patients treated with best medical treatment (BMT), with and without aortic growth, from the Acute Dissection Stent Grafting or Best Medical Treatment (ADSORB) trial database. Furthermore, we looked for trends in outcome for aortic growth and remodeling after BMT and thoracic endovascular aortic repair (TEVAR) and BMT (TEVAR+BMT)., Methods: BMT patients with available baseline and a 1-year follow-up arterial computed tomography scan were identified. True lumen and false lumen diameter was assessed at baseline and at follow-up. Patients with false lumen growth (group I) and without false lumen growth (group II) were compared. Predictors of false lumen and total lumen (aortic) growth were identified. Lastly, BMT outcomes were compared with BMT+TEVAR for false lumen thrombosis and change in false lumen and total aortic diameter in four sections: 0 to 10 cm (A), 10 to 20 cm (B), 20 to 30 cm (C), and 30 to 40 cm (D) from the left subclavian artery., Results: The dissection was significantly longer in group I than in group II (43.2 ± 4.9 cm vs 30.4 ± 8.8 cm; P = .002). The number of vessels originating from the false lumen at baseline was identified as an independent predictor of false lumen growth (odds ratio, 22.1; 95% confidence interval, 1.01-481.5; P = .049). Increasing age was a negative predictor of total aortic diameter growth (odds ratio, 0.902; 95% confidence interval, 0.813-1.00; P = .0502). The proximal sections A and B showed complete thrombosis in 80.6% in the BMT+TEVAR group compared with 9.5% in the BMT group. In these sections, changes from patent to partial or partial to complete thrombosis were observed in 90.3% of the TEVAR+BMT group vs 31.0% in the BMT group. In sections C and D, the change in thrombosis was 74.1% for the TEVAR+BMT group vs 20.6% for the BMT group. The false lumen diameter increase at section C was larger in the BMT group. Total lumen diameter decreased in sections A and B in the TEVAR+BMT group compared with an increase in the BMT group (-4.8 mm vs +2.9 mm, and -1.5 mm vs +3.8 mm, respectively). Sections C and D showed minimal and comparable expansion in both treatment groups., Conclusions: The new imaging analysis of the ADSORB trial patients identified the number of vessels originating from the false lumen as an independent predictor of false lumen growth in uTBAD patients. Increasing age was a negative predictor of aortic growth. Our analysis may help to identify which uTBAD patients are at higher risk and should receive TEVAR or be monitored closely during follow-up., (Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: To compare the results of stent graft placement to balloon angioplasty for the treatment of stenosis at the venous anastomosis of failing and thrombosed prosthetic hemodialysis grafts., Methods: This prospective, multicenter trial included 293 patients randomized (1:1) to the stent graft (n = 145) or balloon angioplasty (n = 148) group for treatment of stenosis at the venous anastomosis of dysfunctional (n = 164) or thrombosed (n = 129) hemodialysis grafts. The primary study end point was target lesion primary patency at 6 months; participants were followed for up to 24 months. Primary patency of the access circuit was a secondary end point. Statistical analysis of effectiveness was performed using both the intent-to-treat population and the effectiveness-per-protocol (EPP) populations for primary patency end points. Statistical analysis of additional effectiveness end points was performed using the EPP population., Results: The 6-month target lesion primary patency was statistically greater in the stent graft group than the balloon angioplasty group (intent-to-treat, 51.6% vs 34.2% [P = .006]; EPP, 52.9% vs 35.5% [P = .008]). Compared with the angioplasty group, the stent graft group increased the median time from the index procedure to the next intervention on the target lesion by 95 days (203 vs 108 days). Patients with dysfunctional (stenotic) grafts had higher target lesion primary patency compared with patients with thrombosed grafts regardless of treatment (EPP, stent graft, 64.6% vs 36.1% and balloon angioplasty, 45.8% vs 23.5%). When compared with angioplasty, using a stent graft for treatment of a venous anastomotic stenosis of a thrombosed graft increased the 6-month target lesion primary patency by 53.6% (EPP, 36.1% vs 23.5%)., Conclusions: When compared with balloon angioplasty, a stent graft provided superior target lesion primary patency at 6 months for treatment of venous anastomotic stenoses of dysfunctional and thrombosed prosthetic hemodialysis grafts., (Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.)

Objective: Despite significant advances in intravascular stent technology, safe prevention of stent thrombosis over prolonged periods after initial deployment persists as a medical need to decrease device failure. The objective of this project was to assess the potential of perfluorocarbon nanoparticles (NP) conjugated with the direct thrombin inhibitor D-phenylalanyl-L-prolyl-L-arginyl chloromethylketone (PPACK-NP) to inhibit stent thrombosis., Methods: In a static model of stent thrombosis, 3 × 3-mm pieces of stainless steel coronary stents were cut and adsorbed with thrombin to create a procoagulant surface that would facilitate thrombus development. After treatment with PPACK-NP or control NP, stents were exposed to platelet-poor plasma (PPP) or platelet-rich plasma (PRP) for set time points up to 60 minutes. Measurements of final clot weight in grams were used for assessing the effect of NP treatment on limiting thrombosis. Additionally, groups of stents were exposed to flowing plasma containing various treatments (saline, free PPACK, control NP, and PPACK-NP) and generated thrombi were stained and imaged to investigate the treatment effects of PPACK-NP under flow conditions., Results: The static model of stent thrombosis used in this study indicated a significant reduction in thrombus deposition with PPACK-NP treatment (0.00067 ± 0.00026 g; n = 3) compared with control NP (0.0098 ± 0.0015 g; n = 3; P = .026) in PPP. Exposure to PRP demonstrated similar effects with PPACK-NP treatment (0.00033 ± 0.00012 g; n = 3) vs control NP treatment (0.0045 ± 0.00012 g; n = 3; P = .000017). In additional studies, stents were exposed to both PRP pretreated with vorapaxar and PPACK-NP, which illustrated adjunctive benefit to oral platelet inhibitors for prevention of stent thrombosis. Additionally, an in vitro model of stent thrombosis under flow conditions established that PPACK-NP treatment inhibited thrombus deposition on stents significantly., Conclusions: This study demonstrates that antithrombin perfluorocarbon NPs exert marked focal antithrombin activity to prevent intravascular stent thrombosis and occlusion., (Copyright © 2015 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective: Expanded polytetrafluoroethylene (ePTFE) grafts have become an acceptable prosthetic alternative to autologous vein for infrainguinal arterial reconstructions. Recently, heparin bonding to the graft's luminal surface has been used as an adjunctive method of improving graft patency. We retrospectively evaluated a prospective experience with heparin-bonded ePTFE (HePTFE) vs the results of a prior experience with standard ePTFE (SePTFE) to compare patency rates in above-knee (AK) and below-knee (BK) femoropopliteal bypass through the 5-year follow-up., Methods: Prosthetic femoropopliteal bypasses performed by our four-surgeon group were constructed using 6-mm SePTFE grafts before August 2007. Subsequently, all such bypasses were constructed using 6-mm HePTFE (Propaten graft; W. L. Gore & Associates, Flagstaff, Ariz). The surgical technique used in all cases throughout the study was similar irrespective of surgeon or graft material. Loss of primary patency was defined by graft thrombosis; duplex scan confirmed graft failure. Descriptive estimation of patency rates was carried out using standard Kaplan-Meier methods. Cox proportional hazards regression was used to analyze relationships between predictors and time to loss of patency., Results: There were 192 AK (87 Propaten, 105 SePTFE) and 60 BK (42 Propaten, 18 SePTFE) grafts. Overall primary patency for Propaten was statistically better than SePTFE at years 1 (93.6% vs 84.2%), 2 (79.7% vs 73.8%), 3 (79.7% vs 69.5%), 4 (74.5% vs 59.9%) and 5 (74.5% vs 56.2%; log-rank test, P = .036). Five-year primary patency was superior for Propaten AK grafts (85.2% vs 59.3%; log-rank test, P = .028) and for Propaten BK grafts (59.6% vs 0.0/undeterminable; log-rank test, P = .016). Variables significantly associated with loss of patency for Propaten and SePTFE were claudication (hazard ratio [HR], 0.41), age (HR, 0.95), isolated popliteal artery (HR, 3.1-4.4), and ankle-brachial index after the procedure (HR, 0.10). Controlling for conduit effect, clopidogrel use did not significantly affect patency (P = .076). No grafts were associated with heparin-induced thrombocytopenia., Conclusions: These data show that the Propaten HePTFE graft offered significantly better long-term patency over the SePTFE graft, suggesting Propaten as the prosthetic graft of choice for bypasses to the femoropopliteal artery when autologous vein is unavailable or inappropriate., (Copyright © 2016. Published by Elsevier Inc.)

Background: The aim of the study was to analyze the use of contrast-enhanced cone beam computed tomography (ceCBCT) during endovascular aneurysm repair (EVAR) and to compare this imaging modality with standard completion digital subtraction angiography (cDSA) and postoperative computed tomography angiography (CTA) regarding the detection of endograft-associated complications., Methods: Between September 2012 and April 2015, ceCBCT was used in 98 EVAR patients in addition to cDSA and CTA. Endoleaks, intraluminal thrombus and limb stenoses, contrast agent use, and radiation exposure were recorded for all modalities., Results: cDSA detected 16 (16.3%) endoleaks; ceCBCT, 35 (35.7%) endoleaks; and CTA, 22 (22.4%) endoleaks. All endoleaks identified by cDSA or CTA were also seen on ceCBCT. ceCBCT detected intraluminal thrombus in three patients (none in cDSA or CTA) and previously undetected limb stenoses in three patients. It prompted intraoperative interventions in 7 of 98 patients (7.1%). Replacing cDSA and CTA by ceCBCT would have caused a 39% reduction of in-hospital contrast agent volume in this cohort., Conclusions: ceCBCT can reliably detect all endograft-associated complications during EVAR. It offers the chance for immediate revision of remediable problems in a relevant proportion of patients and could thus reduce early reintervention rates. ceCBCT can safely replace early follow-up CTA and thereby reduce in-hospital use of contrast media., (Copyright © 2016 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)