Faculty Bibliography

OBJECTIVE:Transplant renal artery stenosis (TRAS) after renal transplantation is a common cause of graft dysfunction and failure. Endovascular intervention in the form of percutaneous transluminal angioplasty (PTA) and stenting has rapidly become the dominant treatment modality for the TRAS. There is a paucity of clinical data on use of drug-eluting stent (DES) for TRAS. We investigated the outcomes of patients with clinically significant TRAS undergoing DES placement. METHODS:A retrospective review of patients with clinically significant TRAS undergoing PTA with DES placement from June 2014 to April 2021 was conducted. Patients treated for TRAS exhibited uncontrolled hypertension and/or unexplained allograft dysfunction. Patient demographics, procedural details, and follow-up outcomes were collected. Primary endpoints were the in-stent primary patency and graft survival. Secondary endpoints were freedom from reintervention, primary-assisted patency and access-related complications. RESULTS:Thirteen TRAS in twelve patients with graft function alteration were treated with DES. The median age was 57 years (interquartile range (IQR), 48-63 years), and nine (70%) patients were male (Table). The median follow-up was 9 months (IQR, 4-52 months). The most common comorbidity was hypertension (100%), coronary artery disease (83%) and diabetes. The median time from deceased donor transplant to intervention was 5.8 months (IQR, 3.5-6.7 months). TRAS was most commonly found at the juxta-ostial segment (77%). The procedure was performed with carbon dioxide angiography with minimal amount of iodinated contrast (median, 3 mL) under local anesthesia in nine (69%) and general anesthesia in four (31%) patients. The median stent diameter was 4.5 mm (IQR, 4-5 mm), and the median stent length was 15 mm (IQR, 15-18 mm). No intraoperative complications occurred. The rates of stenosis-free primary patency of the DES and graft survival were 76% and 100%, respectively. All three reinterventions for restenosis resulted from the kinking of the transplant renal artery proximal to the DES, which were treated by extending the stent more proximally 1-2 mm into the external iliac artery. There were no access-related complications. The median time to reintervention was 0.9 months (range, 0.23-2 months). Freedom from reintervention and primary-assisted patency were 76% and 100%, respectively. CONCLUSIONS:Our study demonstrates that DES is a safe and effective treatment modality in patients with TRAS at short to mid-term follow-up. As all reinterventions after DES were performed due to kinking of the transplant renal artery proximal to the stent, bridging of the DES 1-2 mm into the external iliac artery is recommended.

OBJECTIVE:Carotid artery plaque burden, indirectly measured by the degree of stenosis, quantifies future embolic risk. In natural history studies, patients with moderate degrees of stenosis have a lower stroke risk than those with severe stenosis. However, patients with symptomatic carotid stenosis who have experienced TIA or stroke are found to have both moderate and severe degrees of stenosis. We sought to examine the association carotid artery stenosis severity with outcomes in symptomatic patients undergoing carotid interventions including carotid endarterectomy (CEA), transfemoral carotid artery stenting (CAS) and transcervical carotid artery revascularization (TCAR). METHODS:The Society for Vascular Surgery Quality Initiative database was queried for all patients undergoing CAS, CEA and TCAR between 2003 and 2020. Patients were stratified into two groups based on the severity of stenosis - non-severe (0 - 69%) and severe (≥ 70%). Primary endpoints were periprocedural neurologic events (strokes and transient ischemic attacks (TIAs)). Secondary endpoints were periprocedural death, myocardial infarction (MI) and composite outcomes of stroke/death and stroke/death/MI per reporting standards for carotid interventions. RESULTS:Of 29,614 symptomatic patients included in the analysis, 5,296 (17.9%) patients underwent TCAR, 7,844 (26.5%) underwent CAS, and 16,474 (55.6%) underwent CEA for symptomatic carotid artery stenosis. In the CEA cohort, the neurologic event rate was similarly significantly lower in patients with severe stenosis when compared to those with non-severe stenosis (2.6% vs. 3.2%, P=.024). In the TCAR cohort, the periprocedural neurologic even rate was lower in patients with severe stenosis when compared to those with non-severe stenosis (3% vs. 4.3%, P=.033). There was no similar difference noted in the CAS cohort, with periprocedural neurologic event rates of 3.8% in the severe group versus 3.5% in the non-severe group (P=.518). On multivariable analysis, severe stenosis was associated with significantly decreased odds of post procedural neurologic events in patients undergoing CEA (odds ratio [OR] 0.75, 95% confidence interval [CI], 0.6 - 0.92; P=.007) and TCAR (OR .83; CI, .69 - 0.99; P=.039), but not CAS. CONCLUSION/CONCLUSIONS:Severe carotid stenosis as opposed to more moderate degrees of stenosis was associated with decreased rates of periprocedural stroke and TIAs in symptomatic patients undergoing TCAR and CEA, but not CAS. The finding of increased rates of periprocedural neurologic events in symptomatic patients with lesser degrees of stenosis undergoing TCAR and CEA warrants further evaluation with a particular focus on plaque morphology and brain physiology, and their inherent risks with carotid revascularization procedures.

OBJECTIVES/OBJECTIVE:Endovascular aortic aneurysm repair (EVAR) has become the standard of care treatment for abdominal aortic aneurysms (AAA) in the modern era. While numerous devices exist for standard infrarenal AAA repair, fenestrated endovascular aneurysm repair (fEVAR) offers a minimally invasive alternative to traditional open repair in patients with short infrarenal necks. Over time, aortic neck dilation can occur leading to loss of proximal seal, endoleaks, and AAA sac growth. This study analyzes aortic remodeling following EVAR versus fEVAR and further evaluates whether fEVAR confers a benefit in terms of sac shrinkage. METHODS:A retrospective review of prospectively collected data on 120 patients undergoing EVAR was performed: 30 patients were treated with fEVAR (Cook Zenith© Fenestrated) and 90 patients were treated with EVAR devices (30 with each Medtronic Endurant ©, Gore Excluder ©, and Cook Zenith ©). Demographic data were recorded, and anatomic measurements were taken for each patient pre-operatively, 30 days post-operatively, and at the longest point of follow-up using three-dimensional reconstruction software. RESULTS:There were no significant differences in demographics data between the 4 groups. fEVAR was used more often in aortas with large necks and irregular morphology (p= 0.004). At the time of longest follow up, the suprarenal aorta encompassing 5, 10, and 15mm above the lowest renal artery (ALRA) dilated the most for fEVAR versus all EVAR groups. Despite this, the infrarenal segment tended to increase by the least, or even regress, for fEVAR compared to all EVAR groups, and was associated with the overall greatest proportion of sac shrinkage for the fEVAR group compared to Medtronic, Gore, and Cook devices, respectively (-13.90% vs. -5.75% vs. -2.31% vs. -4.68%, p=0.025). CONCLUSIONS:Compared to EVAR, patients treated with fEVAR had greater suprarenal dilation over time, consistent with an overall greater burden of disease in the proximal native aorta. However, the infrarenal segment dilated significantly less over time in the fEVAR group compared to all EVAR groups, suggesting that fEVAR may stabilize the infrarenal neck, promoting positive sac remodeling, as evidenced by the greatest degree of decrease in largest AAA diameter in the fEVAR group.

OBJECTIVE:Endothermal ablation is well established for the treatment of the great and small saphenous veins. Data are lacking for treatment of the Anterior Accessory Saphenous Vein (AASV). The purpose of this study is to evaluate the safety and efficacy of AASV treatment using endothermal ablation. METHODS:This was a retrospective review of 314 limbs at a single academic institution from 2016-2018 using the institutional Vascular Quality Initiative database. All limbs had documented AASV reflux. Baseline characteristics were evaluated including age, sex, ethnicity, CEAP (clinical, etiology, anatomy, pathophysiology) classification, Venous Clinical Severity Score (VCSS), and vein diameter. Outcomes relating to procedure safety and efficacy included treatment modality and length, successful ablation on post-operative imaging, post-procedural clinical outcomes, incidence of endothermal heat induced thrombosis (EHIT), and any post-procedural complication. RESULTS:A total of 314 consecutive limbs were identified from 2016-2018. Pre-procedure VCSS scores were available for 312 limbs and averaged 6.13 ± 3.33. History of varicose veins were reported in all limbs with 49.4% (n=155) having previously undergone a procedure. The most common presenting symptom was mild edema in 52.5% (n=165). Vein diameter and assessment of reflux were obtained by venous duplex ultrasound (DUS). The largest AASV diameter was available for 304 limbs, averaging 7.93 ± 2.69 mm. Treatment modalities included radiofrequency ablation (RFA) in 59.2% (n=186), endovenous laser ablation (EVLA) in 37.9% (n=119), and isolated microphlebectomy in 2.9% (n=9). 38.5% (N=121) of limbs underwent concomitant microphlebectomy at the time of EVLA. Total treatment length was obtained in 297 limbs, averaging 23.0 cm ± 12.0. Post-operatively, 94.6% (n=297) of limbs were prescribed compression stockings. Post-operative DUS was performed in 312 limbs, revealing successful ablation in 96.5% (n=303) with 2 limbs (0.6%) developing an EHIT, both treated with therapeutic enoxaparin for one week. Repeat DUS revealed thrombus resolution in one limb, while the other patient was lost to follow-up. VCSS scores post-procedure were available for 145 limbs and averaged 4.45 ± 2.31. This was a statistically significant decrease from pre-procedure VCSS scores (p<0.01). Average duration of follow-up was 2.2 years, with two limbs lost to follow-up. Of the 9 limbs (3.5%) whose initial procedure failed, 5 (56%) were treated using RFA and 4 (44%) were treated using EVLA. There were no other post-operative complications. CONCLUSION/CONCLUSIONS:Our experience over a three-year period for treating the AASV shows it to be safe and effective in a broad range of disease severity with an improvement in VCSS and a low incidence of EHIT. Additionally, RFA and EVLA exhibit similar treatment efficacy. Long-term follow-up data are needed.

INTRODUCTION/BACKGROUND:The proportion of open aneurysm repairs requiring at least a suprarenal clamp has increased in the past few decades, partly due to preferred endovascular approaches for most patients with infrarenal aneurysms, suggesting that the management of aortic clamp placement has become even more relevant. This study evaluated the association between proximal clamp site and intraoperative ischemia times with postoperative renal dysfunction and mortality. METHODS:We used the Vascular Quality Initiative to identify all patients undergoing open repairs of elective or symptomatic juxtarenal AAAs from 2004-2018 and compared outcomes by clamp site: above one renal artery, above both renal arteries (supra-renal), or above the celiac trunk (supra-celiac). Outcomes evaluated included acute kidney injury (AKI), new-onset renal failure requiring renal replacement therapy (RRT), 30-day mortality, and one-year mortality. We used multilevel logistic regressions and cox-proportional hazards models, clustered at the hospital level, to adjust for confounding. RESULTS:We identified 3976 patients (median age 71 years, 70% male, 8.2% non-Caucasian), with a median aneurysm diameter of 5.9cm (IQR 5.4-6.8cm). Proximal clamp sites were: above one renal artery (31%), supra-renal (52%), and supra-celiac (17%). Rates of unadjusted outcomes were 20.5% for AKI, 4.1% for new-onset RRT, 4.9% for 30-day mortality, and 8.3% for one-year mortality. On adjusted analyses, independent of ischemia time, supra-renal clamping relative to clamping above a single renal artery had higher odds of postoperative AKI (aOR 1.50 [95%-CI 1.28-1.75]) but similar odds for new-onset RRT (aOR 1.27 [0.79-2.06]) and 30-day mortality (aOR 1.12 [0.79-1.58]) and hazards for one-year mortality (aHR 1.12 [0.86-1.45]). However, every ten minutes of prolonged intraoperative ischemia time was associated with an increase in odds or hazards ratio of postoperative AKI by +7% (IQR 3-11%), new-onset RRT by +11% (IQR 4-17%), 30-day mortality by +11% (IQR 6-17%), and one-year mortality by +7% (IQR 2-13%). Patients with greater than 40 minutes of ischemia time had notably higher rates of all four outcomes. DISCUSSION/CONCLUSIONS:Supra-renal clamping relative to clamping above a single renal artery was associated with AKI but not new-onset RRT or 30-day mortality. However, intraoperative renal ischemia time was independently associated with all four postoperative outcomes. While further studies are warranted, our findings suggest that an expeditious proximal anastomosis creation is more important than trying to maintain clamp position below one renal artery, suggesting that suprarenal clamping may be the best strategy for open AAA repair when needed to efficiently perform the proximal anastomosis.

Objective: The continuation of antiplatelet agents in the periprocedural period around carotid stenting (transfemoral carotid artery stenting [TF-CAS] and transcarotid artery revascularization [TCAR]) procedures is believed to be mandatory to minimize the risk of periprocedural stroke.
Method(s): The Society for Vascular Surgery Vascular Quality Initiative database was queried from 2007 to 2020. All TCAR and TF-CAS procedures were included. The patients were stratified by preoperative use of P2Y12 inhibitors. The primary endpoints were perioperative neurologic events (ie, stroke, transient ischemic attack). The secondary endpoints were mortality and myocardial infarction. The P2Y12 inhibitors included in the analysis were clopidogrel, prasugrel, and ticagrelor.
Result(s): A total of 31,036 carotid stent procedures were included for analysis (49.8% TCAR and 50.2% TF-CAS; 63.8% of the patients were men). Overall, 82.3% of the patients were taking a P2Y12 inhibitor. P2Y12 inhibitor use was significantly more common for men, asymptomatic patients, those aged >70 years, and those with concurrent statin use (Table I). P2Y12 inhibitors were significantly more likely to be used with TCAR cases than with TF-CAS cases (87.3% vs 76.8%; P <.001). The rate of periprocedural neurologic events in the whole cohort was 2.6%. Patients taking P2Y12 inhibitors were significantly less likely to experience a periprocedural neurologic event (2.3% vs 3.9%; P <.001) and periprocedural mortality (0.6% vs 2.1%; P <.001) than were those not taking a P2Y12 inhibitor. No effect was seen on the rates of myocardial infarction. On multivariate analysis, the use of P2Y12 inhibitors demonstrated an independent significant effect in reducing of the rate of perioperative stroke (odds ratio, 0.29; 95% confidence interval, 0.25-0.33; Table II). Finally, additional analysis of the types of P2Y12 inhibitors used revealed that all appeared to be equally effective in reducing the periprocedural neurologic event rate.
Conclusion(s): Continuation of P2Y12 inhibitors in the periprocedural period appears to markedly reduce the perioperative neurologic event rate with TCAR and TF-CAS and should be considered mandatory. Patients with contraindications to P2Y12 inhibitors might not be appropriate candidates for any carotid stenting procedure. Additionally, alternative types of P2Y12 inhibitors appear to be equally effective as clopidogrel. Finally, analysis of the Vascular Quality Initiative demonstrated that even for TCAR cases, only 87.3% of patients were receiving P2Y12 inhibitor therapy in the periprocedural period, leaving room for significant improvement. [Formula presented] [Formula presented]
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Objective: Celiac artery aneurysms (CAAs) are unusual. The reported literature is skewed toward those treated by operative or endovascular intervention. The goal of the present study was to investigate the natural history of untreated CAAs.
Method(s): We performed a single-institution retrospective analysis of patients with CAAs diagnosed by computed tomography from 2015 to 2019. The patients were identified by searching our institutional radiology database. The radiologic, demographic, and follow-up clinical and imaging data were obtained from the electronic medical records.
Result(s): The analyzed cohort consisted of 76 patients (86.8% were men). The mean age was 69.8 years (range, 29-93 years). The medical comorbidities included hypertension (64.5%), diabetes (9.2%), coronary disease (18.4%), and hypercholesterolemia (46.1%). Concomitant vascular disease was noted and included AAA in 13.2%, an additional visceral aneurysm in 10.5%, and a visceral artery anomaly in 11.8%. The mean CAA diameter at the index study was 15.4 mm (range, 7-30 mm). Most (97.3%) were believed to be true aneurysms. Additional characteristics included thrombus (9.2%), calcification (26.3%), and dissection (11.8%). Of the 76 patients, 45 (59.2%) had had follow-up imaging data available for analysis. The mean clinical follow-up time was 31.2 months. The follow-up time for only those with subsequent imaging studies available was 25.2 months. During this period, 16 CAAs (21.1%) had enlarged in size and 29 (79.9%) had remained stable. No patient had developed symptoms or rupture. One patient (1.3%) had undergone intervention for an increasing size in the setting of chronic dissection. On univariate analysis, the only factor that was significantly associated with an increased risk of growth was younger age (mean age at diagnosis, 63.4 years vs 74.3 years; P =.005). We could not identify any other factor that was significantly predictive of, or protective against, aneurysm growth. For patients with follow-up imaging studies available, the freedom from aneurysm growth or intervention was 63% at 37 months. For the entire cohort, the freedom from aneurysm rupture or the need for intervention was 90% at 59 months.
Conclusion(s): The results from the present large study of patients with untreated CAAs revealed that very few lesions either enlarged to a clinically meaningful degree, became symptomatic, or required intervention during a 31.2-month follow-up period. Guidelines that suggest repair of CAAs >=2 cm in diameter might be overly aggressive. Close follow-up with serial imaging studies, especially for patients who are younger at diagnosis, might be preferred for most patients with an incidentally noted true CAA.
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INTRODUCTION AND OBJECTIVES: The impact of preoperative statin use in patients undergoing transcarotid artery revascularization (TCAR) is not well established. The aim of this study was to evaluate the effect of statin on postoperative outcomes after TCAR.
METHOD(S): Vascular Quality Initiative registry (2012-2020) was queried for patients undergoing TCAR. Patient demographics, perioperative characteristics and 30-day outcomes were compared between patients treated with and without statins at least 30 days preoperatively. Multivariable logistic regression models were used to estimate the effect of statins on postoperative outcomes. RESULTS: A total of 15,797 patients underwent TCAR, and 10,116 (64%) were males. 14,152 (89.6%) patients were on statin preoperatively (Table). There was higher incidence of both prior ipsilateral stroke (17.2% vs 13.5%; P<.001) and recent ipsilateral stroke (<= 30 days; 7.1% vs 5.6%; P=.02) in the statin group. Perioperative stroke and major adverse cardiac event (MACE; myocardial infarction, congestive heart failure and dysrhythmia) occurred in 1.5% and 2.4% among patients on statins and 1.4% and 2.3% among those not on statins, respectively. After adjusting for potential confounders and baseline differences, statin use was associated with 62% reduction in the odds of mortality (OR 0.38; 95% CI, 0.19-0.99; P=.047) in patients who developed a perioperative stroke or MACE after TCAR (Figure).
CONCLUSION(S): Statin use was associated with a significant reduction in postoperative mortality in patients who develop a stroke or MACE after TCAR. Therefore, strict adherence to statin is strongly recommended, particularly in patients who may be at high risk of major postoperative complications.[Formula presented]
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Mechanical overload of the vascular wall is a pathological hallmark of life-threatening abdominal aortic aneurysms (AAA). However, how this mechanical stress resonates at the unicellular level of vascular smooth muscle cells (VSMC) is undefined. Here we show defective mechano-phenotype signatures of VSMC in AAA measured with ultrasound tweezers-based micromechanical system and single-cell RNA sequencing technique. Theoretical modelling predicts that cytoskeleton alterations fuel cell membrane tension of VSMC, thereby modulating their mechanoallostatic responses which are validated by live micromechanical measurements. Mechanistically, VSMC gradually adopt a mechanically solid-like state by upregulating cytoskeleton crosslinker, α-actinin2, in the presence of AAA-promoting signal, Netrin-1, thereby directly powering the activity of mechanosensory ion channel Piezo1. Inhibition of Piezo1 prevents mice from developing AAA by alleviating pathological vascular remodeling. Our findings demonstrate that deviations of mechanosensation behaviors of VSMC is detrimental for AAA and identifies Piezo1 as a novel culprit of mechanically fatigued aorta in AAA.

OBJECTIVE:Type II endoleaks (T2Es), often identified after endovascular aneurysm repair (EVAR), have been associated with late endograft failure and secondary rupture. The number and size of the patent aortic aneurysm sac outflow vessels (ie, the inferior mesenteric, lumbar, and accessory renal arteries) have been implicated as known risk factors for persistent T2Es. Given the technical challenges associated with post-EVAR embolization, prophylactic embolization of aortic aneurysm sac outflow vessels has been advocated to prevent T2Es; however, the evidence available at present is limited. We sought to examine the effects of concomitant prophylactic aortic aneurysm sac outflow vessel embolization in patients undergoing EVAR. METHODS:Patients aged ≥18 years included in the Society for Vascular Surgery Vascular Quality Initiative database who had undergone elective EVAR for intact aneurysms between January 2009 and November 2020 were included in the present study. Patients with a history of prior aortic repair and those without available follow-up data were excluded. The patient demographics, operative characteristics, and outcomes were analyzed by group: EVAR alone vs EVAR with prophylactic sac outflow vessel embolization (emboEVAR). The outcomes of interest were the in-hospital postoperative complication rates, incidence of aneurysmal sac regression (≥5 mm) and T2Es, and reintervention rates during follow-up. RESULTS:A total of 15,060 patients were included. Of these patients, 272 had undergone emboEVAR and 14,788 had undergone EVAR alone. No significant differences were found between the two groups in age, comorbidities, or anatomic characteristics, including the mean maximum preoperative aortic diameter (5.5 vs 5.6 cm; P = .48). emboEVAR was associated with significantly longer procedural times (148 vs 124 minutes; P < .0001), prolonged fluoroscopy times (32 vs 23 minutes; P < .0001), increased contrast use (105 vs 91 mL; P < .0001), without a significant reduction in T2Es at case completion (17.7% vs 16.3%; P = .54). The incidence of postoperative complications (3.7% vs 4.6%; P = .56), index hospitalization reintervention rates (0.7% vs 1.3%; P = .59), length of stay (1.8 vs 2 days; P = .75), and 30-day mortality (0% vs 0%; P = 1.00) were similar between the two groups. At mid-term follow-up (14.6 ± 6.2 months), the emboEVAR group had a significantly greater mean reduction in the maximum aortic diameter (0.69 vs 0.54 cm; P = .006), with a greater proportion experiencing sac regression of ≥5 mm (53.5% vs 48.7%). The reintervention rates were similar between the two groups. On multivariable analysis, prophylactic aortic aneurysm sac outflow vessel embolization (odds ratio, 1.34; 95% confidence interval, 1.04-1.74; P = .024) was a significant independent predictor of sac regression. CONCLUSIONS:Prophylactic sac outflow vessel embolization can be performed safely for patients with intact aortic aneurysms undergoing elective EVAR without significant associated perioperative morbidity or mortality. emboEVAR was associated with significant sac regression compared with EVAR alone at mid-term follow-up. Although no decrease was found in the incidence of T2Es, this technique shows promise, and future efforts should focus on identifying a subset of aneurysm and outflow branch characteristics that will benefit from concomitant selective vs complete prophylactic sac outflow vessel embolization.