Faculty Bibliography

OBJECTIVE:Restenosis after carotid endarterectomy (CEA) poses unique therapeutic challenges, with no specific guidelines available on the operative approach. Traditionally, transfemoral carotid artery stenting (TfCAS) has been regarded as the preferred approach to treating restenosis after CEA. Recently, transcarotid artery revascularization with a flow-reversal neuroprotection system (TCAR) has gained popularity as an effective alternative treatment modality for de novo carotid artery stenosis. The aim of the present study was to compare the contemporary perioperative outcomes of TfCAS and TCAR in patients with prior ipsilateral CEA. METHODS:The Vascular Quality Initiative database was reviewed for patients who had undergone TfCAS and TCAR for restenosis after prior ipsilateral CEA between January 2016 and August 2020. The primary outcome was the 30-day composite outcome of stroke and death. The secondary outcomes included 30-day stroke, transient ischemic attack (TIA), myocardial infarction (MI), death, and composite 30-day outcomes of stroke, death, and TIA, stroke and TIA, and stroke, death, and MI. Multivariable logistic regression models were used to evaluate the outcomes of interest after adjustment for potential confounders and baseline differences between cohorts. RESULTS:Of 3508 patients, 1834 and 1674 had undergone TfCAS and TCAR, respectively. The TCAR cohort was older (mean age, 71.6 years vs 70.2 years; P < .001) and less likely to be symptomatic (27% vs 46%; P < .001), with a greater proportion taking aspirin (92% vs 88%; P = .001), a P2Y12 inhibitor (89% vs 80%; P < .001), and a statin (91% vs 87%; P = .002) compared with the TfCAS cohort. Perioperatively, the TCAR cohort had had lower 30-day composite outcomes of stroke/death (1.6% vs 2.7%; P = .025), stroke/death/TIA (1.8% vs 3.3%; P = .004), and stroke/death/MI (2.1% vs 3.2%; P = .048), primarily driven by lower rates of stroke (1.3% vs 2.3%; P = .031) and TIA (0.2% vs 0.7%; P = .031). Among asymptomatic patients, the incidence of stroke (0.6% vs 1.4%; P = .042) and the composite of stroke/TIA (0.8% vs 1.8%; P = .036) was significantly lower after TCAR than TfCAS, and TCAR was associated with a lower incidence of TIA (0% vs 1%; P = .038) among symptomatic patients. On adjusted analysis, the TCAR cohort had lower odds of TIA (adjusted odds ratio, 0.17; 95% confidence interval, 0.04-0.74; P = .019). CONCLUSIONS:Among patients undergoing carotid revascularization for restenosis after prior ipsilateral CEA, TCAR was associated with decreased odds of 30-day TIA compared with TfCAS. However, the two treatment approaches were similarly safe in terms of the remaining perioperative outcomes, including stroke and death and stroke, death, and MI. Our results support the safety and efficacy of TCAR in this subset of patients deemed at high risk of reintervention.

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.

BACKGROUND:Histological analyses of deep vein thrombi (DVT) are based on autopsy samples and animal models. No prior study has reported on thrombus composition following percutaneous mechanical extraction. As elements of chronicity and organization render thrombus resistant to anticoagulation and thrombolysis, a better understanding of clot evolution may inform therapies. METHODS:We performed histologic evaluation of DVTs from consecutive patients undergoing mechanical thrombectomy for extensive iliofemoral DVTs using the Clottriever/ Flowtriever device (Inari Medical, Irvine, CA). Thrombi were scored in a semi-quantitative manner based on the degree of fibrosis (collagen deposition on trichrome stain), and organization (endothelial growth with capillaries and fibroblastic penetration). RESULTS:Twenty-three specimens were available for analysis with 20 presenting with acute DVT (≤14 days from symptom onset). Eleven of 23 patients (48%) had >5% fibrosis (collagen deposition) and 14/23 patients (61%) had >5% organization (endothelial growth, capillaries, fibroblasts). Four patients with acute DVT had ≥25% organized thrombus and 2 had ≥ 25% collagen deposition. Among the 20 patients with acute DVT, 40% had >5% fibrosis and 55% had > 5% organization. Acuity of DVT did not correlate with the fibrosis or organizing scores. CONCLUSIONS:A large proportion of patients with acute DVT have histologic elements of chronicity and fibrosis. A better understanding of the relationship between such elements and response to anticoagulants and fibrinolytics may inform our approach to therapeutics.

OBJECTIVE:Contemporary commercially available endovascular devices for the treatment of abdominal aortic aneurysm (AAA) include standard endovascular aortic repair (sEVAR) or fenestrated EVAR (fEVAR) endografts. However, aortic neck dilatation (AND) can occur in nearly 25% of patients following EVAR, resulting in loss of proximal seal with risk of aortic rupture. AND has not been well characterized in fEVAR, and direct comparisons studying AND between fEVAR and sEVAR have not been performed. This study aims to analyze AND in the infrarenal and suprarenal aortic segments, including seal zone, and quantify sac regression following fEVAR implantation compared to sEVAR. METHOD/METHODS:A retrospective review of prospectively collected data on 20 consecutive fEVAR patients (Cook Zenith® Fenestrated) and 20 sEVAR (Cook Zenith®) patients was performed. Demographic data, anatomic characteristics, procedural details, and clinical outcome were analyzed. Pre-operative, post-operative (1 month), and longest follow-up CT scan at an average of 29.3 months for fEVAR and 29.8 months for sEVAR were analyzed using a dedicated 3D workstation (iNtuition, TeraRecon Inc, Foster City, California). Abdominal aortic aneurysm neck diameter was measured in 5 mm increments, ranging from 20 mm above to 20 mm below the lowest renal artery. Sub-analysis comparing the fEVAR to the sEVAR group at 12 months and at greater than 30 months was performed. Standard statistical analysis was done. RESULTS:Demographic characteristics did not differ significantly between the two cohorts. The fEVAR group had a larger mean aortic diameter at the lowest renal artery, shorter infrarenal aortic neck length, increased prevalence of nonparallel neck shape, and longer AAA length. On follow-up imaging, the suprarenal aortic segment dilated significantly more at all locations in the fEVAR cohort, whereas the infrarenal aortic neck segment dilated significantly less compared to the sEVAR group. Compared to the sEVAR cohort, the fEVAR patients demonstrated significantly greater positive sac remodeling as evident by more sac diameter regression, and elongation of distance measured from the celiac axis to the most cephalad margin of the sac. Device migration, endoleak occurrence, re-intervention rate, and mortalities were similar in both groups. CONCLUSION/CONCLUSIONS:Compared to sEVAR, patients undergoing fEVAR had greater extent of suprarenal AND, consistent with a more diseased native proximal aorta. However, the infrarenal neck, which is shorter and also more diseased in fEVAR patients, appears more stable in the post-operative period as compared to sEVAR. Moreover, the fEVAR cohort had significantly greater sac shrinkage and improved aortic remodeling. The suprarenal seal zone in fEVAR may result in a previously undescribed increased level of protection against infrarenal neck dilatation. We hypothesize that the resultant decreased endotension conferred by better seal zone may be responsible for a more dramatic sac shrinkage in fEVAR.

Arteriovenous fistula is a rare and often unrecognized complication of aneurysms, with a varied and frequently inconsistent presentation. We present the case of an ilio-iliac arteriovenous fistula formation in a 71-year-old man associated with a type III endoleak after endovascular iliac branch repair. Because of rapidly progressing congestive heart failure and hepatorenal syndrome, we performed urgent endovascular repair with successful endoleak exclusion. After the procedure, the patient demonstrated a remarkably rapid and complete recovery.

OBJECTIVE:There is a lack of evidence regarding the effect of anticoagulation and antiplatelet medications on aortic remodeling for aortic dissection after endovascular repair. We investigated whether anticoagulation and antiplatelet medications affect aortic remodeling after thoracic endovascular aortic repair (TEVAR) for Type B aortic dissection (TBAD). METHODS:Records of the Vascular Quality Initiative TEVAR registry (2012-2020) were reviewed. Procedures performed for TBAD were included. Aortic reintervention, false lumen thrombosis of the treated aorta and all-cause mortality at follow-up were compared between patients treated with and without anticoagulation medications. A secondary analysis was performed to assess the effect of antiplatelet therapy in patients not on anticoagulation. Cox proportional hazards models were used to estimate the effect of anticoagulation and antiplatelet therapies on outcomes. RESULTS:1,210 patients (mean age, 60.7±12.2 years; 825 (68%) males) were identified with a mean follow-up of 21.2±15.7 months (range 1-94 months). 166 (14%) patients were on anticoagulation medications at discharge and at follow-up. Patients on anticoagulation were more likely to be older (mean age, 65.5 vs 60 years; P<.001) and Caucasian (69% vs 55%; P=.003), with higher proportions of coronary artery disease (10% vs 3%; P<.001), congestive heart failure (10% vs 2%; P<.001) and chronic obstructive pulmonary disease (15% vs 9%; P=.017). There were no differences in the mean preoperative thoracic aortic diameter or the number of endografts used. At 18-month, the rates of aortic reinterventions (8% vs 9% log-rank P=.873), complete false lumen thrombosis (52% vs 45%; P=.175) and mortality (2.5% vs 2.7%; P=.209) were similar in patients with and without anticoagulation, respectively. Controlling for covariates with the Cox regression method, anticoagulation use was not independently associated with a decreased rates of complete false lumen thrombosis (hazard ratio (HR) 0.74; 95% confidence interval (CI), 0.5-1.1; P=.132), increased need for aortic reinterventions (HR 1.02; 95% CI, 0.62-1.68; P=.934), and mortality (HR 1.25; 95% CI, 0.64-2.47; P=.514). On a secondary analysis, antiplatelet medications did not affect the rates of aortic reintervention, complete false lumen thrombosis and mortality. CONCLUSIONS:Anticoagulation and antiplatelet medications do not appear to negatively influence the midterm endpoints of aortic reintervention or death in patients undergoing TEVAR for TBAD. Moreover, it did not impair complete false lumen thrombosis. Anticoagulation and antiplatelet medications do not adversely affect aortic remodeling and survival in this population at midterm.

OBJECTIVES/OBJECTIVE:Presence of an endoleak can compromise aneurysm exclusion after endovascular abdominal aortic aneurysm repair(EVAR). Type II endoleaks(T2Es) are most common and may cause sac expansion. We report outcomes of translumbar embolization(TLE) of T2Es following EVAR. METHODS:We conducted a retrospective chart review of patients with T2E after EVAR treated with TLE from 2011-2018 at a single academic institution. Treatment indications were the presence of persistent T2E and aneurysm growth ≥5mm. Sac stabilization was defined as growth ≤5mm throughout the follow-up period. RESULTS:Thirty consecutive patients were identified. The majority were men (n=24) with a mean age of 74.3 years (70.9-77.6, 95% CI). The most common comorbidities were hypertension (83.3%) and coronary artery disease (54.0%). The mean maximal sac diameter at T2E discovery was 5.8 cm (5.4-6.2, 95% CI). The mean time to intervention from endoleak discovery was 33.7±28 months with a mean growth of 0.84 cm (0.48-1.2, 95% CI) during that time period. The mean follow-up time after TLE was 19.1 months (11.1-27.2, 95% CI). Twenty-eight patients were treated with cyanoacrylate glue(CyG) alone, and 2 were treated with CyG plus coil embolization(CE). There was immediate complete endoleak resolution as assessed intraoperatively, and sac stabilization in 15 cases (50.0%). Eleven (36.7%) patients had evidence of persistent T2E on initial imaging after the embolization procedure; additional follow-up revealed eventual sac stabilization at a mean of 21.3±7.2 months and therefore these patients did not require further intervention. In the remaining four cases (13.3%) there was persistent T2E after the initial TLE requiring a second intervention. Repeat TLE stabilized growth in three of these four patients after a mean of 17.6±12.9 months. One patient required open sacotomy and ligation of lumbar vessels due to continued persistence of the T2E and continued aneurysm growth. There were no ischemic complications related to the embolization procedures. Factors associated with persistent endoleak after initial embolization were: larger aneurysm diameter at the time of initial endoleak identification (p<0.001), and the use of antiplatelet agents (p<0.02). The use of anticoagulation was not a significant risk factor for endoleak recurrence or aneurysm growth after TLE. CONCLUSIONS:TLE of T2E is a safe and effective treatment option for T2E with aneurysm growth following EVAR. Patients taking antiplatelet medication and those with larger aneurysms at the time of endoleak identification appear to be at increased risk for persistent endoleak and need for subsequent procedures following initial TLE. These patients may require more intensive monitoring and follow-up.

OBJECTIVE:Over the past two decades, the treatment of popliteal artery aneurysms (PAAs) has undergone a transformation. While open surgical repair (OR) remains the gold standard for treatment, endovascular repair (ER) has become an attractive alternative in select patient populations. The objective of this study was to compare the outcomes of open versus endovascular repair of PAAs at a single institution. METHODS:We performed a retrospective chart review of all patients between 1998 and 2017 who underwent repair for PAA. Patient baseline, anatomic, and operative characteristics as well as outcomes were compared between the open and endovascular cohorts. The intervention and treatment were at the discretion of the surgeon. RESULTS:Between 1998 and 2017, a total of 64 patients underwent repair of 73 PAAs at our tertiary care center. Twenty-nine patients with 33 PAAs underwent OR, and 35 patients with 40 PAAs underwent ER. When comparing the 2 cohorts, there were no statistically significant differences in demographic characteristics such as age, gender, or number of run-off vessels. There were significantly more patients in the ER group (21/53%) than the OR group (7/21%) with hyperlipidemia (p=.008) and a prior carotid intervention (6% vs. 0%, p=.029). Overall, the presence of symptoms was similar amongst the two groups; however, patients in the OR group had a significantly higher number of patients presenting with acute ischemia (p=.01). Length of stay (LOS) was significantly shorter in the ER cohort (mean 1.8 days [1-11]) compared to the OR group (5.4 days [2-13]) (p<.0001). There was no significant difference in primary or secondary patency rates between the two groups. In the ER group, good runoff (≥2 vessels) was a positive predictor for primary patency at 1 year (3.36 [1.0-11.25]), however, it was not in the OR group. Post-operative single and/or dual anti-platelet therapy did not affect primary patency in either cohort. CONCLUSIONS:The results of our study demonstrate that ER of PAAs is a safe and durable option with comparable patency rates to OR and a decreased LOS, with good run-off being a positive predictor for primary patency in the ER cohort.