Faculty Bibliography

OBJECTIVES/OBJECTIVE:In patients deemed high risk for carotid endarterectomy (CEA) who are indicated for treatment of carotid artery stenosis (CAS), transcarotid artery revascularization (TCAR) has been demonstrated as a safe and effective alternative to trans-femoral carotid artery stenting (TF-CAS). Compared to CEA, where approx. 12% of patients undergoing awake intervention do not tolerate internal carotid artery (ICA) clamping, only 1-2% of patients were observed to have intolerance to flow reversal during TCAR based on data from the ROADSTER1/2 trials. This study reviewed awake interventions from those trials to assess factors associated with intolerance to flow reversal and review how those cases were managed. METHODS:This is a retrospective review of prospectively collected data from Reverse Flow Used During Carotid Artery Stenting Procedure (ROADSTER) multicenter trial along with the subsequent post-approval (ROADSTER-2) trial. The subset of patients from both trials undergoing awake TCAR was analyzed to compare demographics, procedural details, and anatomic factors between patients who did and did not experience intolerance to reversal of flow to assess for predisposing factors. Patients were deemed intolerant to flow reversal at the discretion of the operator, often related to changes in completion of neurologic tasks, hemodynamic stability, or patient reported symptoms. RESULTS:103 patients from ROADSTER and 194 patients from ROADSTER-2 underwent TCAR under local/regional anesthesia. Of these, 8 patients had intolerance to flow reversal, though all cases were successfully completed. While intra-operative hemodynamic data was only available for 5 of the 8 intolerant patients, none experienced hypotension. 4 cases were completed under low flow reversal, 3 cases were successfully weaned from low to high flow over several minutes, and 1 case required general anesthesia. No significant association was found between intolerance to flow reversal and comorbidities including diabetes mellitus (DM), hypertension (HTN), hyperlipidemia (HLD), congestive heart failure (CHF), prior MI or angina, pre-op CAS-related symptoms, prior stroke, prior CAS or CEA, prior neck radiation, tandem stenosis, high cervical stenosis, or hostile neck (tables 1, 2). A trend towards significance was seen with chronic obstructive pulmonary disease (COPD) and contralateral carotid artery occlusion (p= 0.086 and 0.139, respectively). CONCLUSIONS:Despite intolerance to flow reversal, TCAR cases were successfully completed by adjusting reversal-of-flow rate and do not typically require conversion to GETA. While factors contributing to intolerance of flow reversal during TCAR remain poorly understood, this study identified a trend towards significance with an association of pre-existing COPD and contralateral carotid artery occlusion. Given the low number of patients who experienced this issue, a larger sample size is required to better elucidate these trends.

INTRODUCTION/BACKGROUND:The treatment of a refluxing perforator is indicated in the setting of severe chronic venous insufficiency, but there are limited data on the presence of multilevel disease in these patients. This study sought to evaluate whether the presence of a pathologic perforator is predictive of the presence of central venous pathology. METHODS:This study was a retrospective review of the institutional vascular quality initiative (VQI) database. Consecutive patient-limbs were identified who underwent intervention of refluxing perforators. The patients who underwent imaging, including MRI or CT (Group A) were compared to those who did not undergo imaging (Group B). The treated limbs in Group A were also compared to the contralateral limbs as an internal control. Anatomical findings on imaging were analyzed by two independent investigators. The primary outcome was the presence and degree of central venous stenosis as measured by an orthogonal diameter reduction of > 50% by axial imaging. Secondary outcomes included demographic and clinical differences between the two groups, frequency of central venous intervention, and duration of ulcer healing. Standard statistical analysis was performed. RESULTS:Ninety-three patient-limbs underwent treatment of a pathologic perforator, with 30 in Group A and 63 in Group B. The following demographic and clinical variables were higher in Group A compared to Group B: Male gender, BMI, deep venous thrombosis history, recent or active anticoagulation use, perforator diameter, Clinical Etiology Anatomy Pathophysiology class 4, 5 or 6, and Venous Clinical Severity Score. Radiographic analysis of Group A revealed concordance of a treated pathological perforator with an ipsilateral central venous stenosis in 53.3% of patients, and a higher frequency of common iliac vein stenosis (50% vs 21.4%, P = 0.024) and external iliac vein stenosis (20% vs 0%, P = 0.012) compared to the contralateral limbs. When separated by left or right limb, the left limbs exhibited a greater degree of common iliac vein stenosis as compared to the contralateral limbs (50.7±20.9% vs 16.3±16.5%, P < 0.001) as well as a greater frequency of >50% common iliac vein stenosis (46.7% vs 13.3%, P = 0.046). The right limbs exhibited a greater frequency of > 50% external iliac vein stenosis as compared to contralateral limbs (33.3% vs 0%, P = 0.022). CONCLUSIONS:This study suggests that patients with severe chronic venous insufficiency who undergo treatment for a pathologic perforator may have additional ipsilateral central venous pathology, supporting the presence of multilevel disease. Additional axial imaging might unmask central venous pathology and provide another option for treatment.

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.

Background: Severe presentations of chronic venous insufficiency may result from reflux or obstruction at the deep venous, perforator or superficial venous levels. Iliofemoral venous stenting may be used to address central venous obstruction, but its effect on deep venous reflux remains unclear. The purpose of this study was to evaluate the effect of iliac vein stenting on femoropopliteal deep vein reflux with the hypothesis that sonographic evidence of deep vein reflux would remain absent or improve following iliac vein stenting.
Method(s): This study was a retrospective review of patients undergoing iliofemoral venous stenting from 2013-2020. Patients were divided into two cohorts based on the preprocedural presence (Group A) or absence (Group B) of femoropopliteal reflux. Baseline patient variables were collected including age, gender, CEAP, presence of concomitant superficial or perforator reflux, DVT history, and additional venous intervention(s). The primary outcome evaluated was the persistent absence or the resolution of deep vein reflux on the latest venous duplex ultrasound follow-up. Other outcomes included follow-up CEAP classification as well as need for secondary deep venous interventions.
Result(s): There were 275 consecutive patients who underwent iliofemoral venous stenting. Of those, 58 presented with deep vein reflux (Group A), and the remaining did not (Group B). When comparing Group A and Group B, patients in Group A had a higher likelihood of prior DVT (P =.0001) as well as higher frequency of venous ablation (Table). The remaining demographics did not differ significantly between the two groups. In Group A, deep vein reflux resolved in follow-up in 17/51 patients (P =.0001). In Group B, deep vein reflux developed on follow-up in 6/217 patients. CEAP appeared to improve from preintervention (C0, 1.1%; C1, 0.4%; C2, 1.8%; C3, 41.4%; C4, 24.9%; C5, 5.9%; and C6, 24.5%) to latest follow-up (C0, 4.9%; C1, 1.9%; C2, 5.7%; C3, 34.2%; C4, 22.8%; C5, 17.1%; and C6, 13.3%).
Conclusion(s): For patients who undergo iliofemoral vein stenting, deep vein reflux may improve if present initially, and is unlikely to develop if not present prior to intervention. A cohort of patients maintained persistent deep vein reflux, and these warrant further evaluation. Prospective studies are required to corroborate the safety, efficacy and durability of iliofemoral venous stenting in patients with deep vein reflux. [Formula presented]
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Objective: Statins are often used for primary and secondary prevention of cardiovascular events. Multiple studies have demonstrated a significant reduction in perioperative complications after carotid endarterectomy for patients taking statins. However, data for statin use for patients undergoing transcarotid artery revascularization (TCAR) are limited. We evaluated the effects of statin use on the postoperative outcomes after TCAR.
Method(s): The records of the Vascular Quality Initiative carotid artery stenting registry (2012-2020) were reviewed for patients who had undergone TCAR. The patient demographics, perioperative characteristics, and 30-day outcomes were compared between the patients treated with and without statins (statin and no-statin group, respectively). Multivariable logistic regression models were used to estimate the effect of statins on the postoperative outcomes.
Result(s): A total of 15,797 patients had undergone TCAR, of whom, 10,116 (64%) were men. Of the 15,797 patients, 14,152 (89.6%) were taking a statin preoperatively (Table I). The statin group was more likely to have hypertension (91% vs 87%; P <.001), coronary artery disease (26% vs 23%; P =.008), and diabetes mellitus (33% vs 29%; P <.001). The 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) was higher in the statin group. No differences were found in the perioperative characteristics, including median operative time, contrast amount used, technical success, and number of stents used. Perioperative stroke and major adverse cardiac events (MACE; myocardial infarction, congestive heart failure, dysrhythmia) occurred in 1.5% and 2.4% of the statin group and 1.4% and 2.3% of the no-statin group, respectively. Controlling for covariates with the logistic regression method, statin use was associated with a 62% reduction in the odds of mortality (odds ratio, 0.38; 95% confidence interval, 0.19-0.99; P =.047; Table II) for patients who had experienced a perioperative stroke or MACE after TCAR.
Conclusion(s): Statin use was associated with a significant reduction in postoperative mortality for patients who had experienced a stroke or MACE after TCAR. Therefore, strict adherence to statin use is strongly recommended, especially for patients who could be at high risk of major postoperative complications. [Formula presented] [Formula presented]
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Objectives: Current guidelines recommend dual antiplatelet therapy (DAPT) in patients undergoing carotid artery stenting. The most common DAPT regimen is aspirin and clopidogrel, a P2Y12 receptor antagonist; however, there is evidence that the prevalence of clopidogrel resistance (CR) in patients undergoing percutaneous coronary interventions may exceed 40%. Few studies have investigated the prevalence and impact of CR in patients undergoing extracranial carotid artery stenting, particularly transcarotid artery revascularization (TCAR).
Method(s): Consecutive patients 18 years and older who underwent TCAR for high grade (>80%) or symptomatic (>50%) carotid stenosis with preoperative P2Y12 testing between January 2018 and January 2021 were identified across six institutions. Preoperative platelet reactivity was measured with the light transmission aggregometry (VerifyNow P2Y12 Reaction Units [PRU] Test; Instrumentation Laboratory, Bedford, MA), with CR defined as PRU >=194 and hyper-responders as PRU <70. Patients without preoperative P2Y12 testing within 30 days prior to TCAR or those on a non-clopidogrel P2Y12 inhibitor preoperatively were excluded. Primary outcome of interest was the prevalence of CR. Secondary outcomes included the incidence of ischemic and hemorrhagic complications.
Result(s): Of the 67 patients identified, 60 met inclusion criteria. The cohort was 63% male (38/60) and 62% (37/60) Caucasian, with mean age of 74 years (+/-8; range, 56-92 years). Preoperatively, 95% of patients were on aspirin, 100% on clopidogrel, and 15% on therapeutic anticoagulation. At presentation, 42% (25) were symptomatic. Mean preoperative P2Y12 was 168 PRU (+/-81; range, 6-349 PRU). In total, 23 patients (38%) met criteria for CR (mean PRU, 249 +/- 43; range, 197-349), and 8 patients (13%) met criteria for hyper-responder (mean PRU, 35 +/- 22; range, 6-64). There was no significant difference between clopidogrel responders and patients with CR in terms of age (P =.1447), gender (P = 1), race (P =.387), or symptomatic presentation (P =.319). Postoperatively, there were no in-hospital transient ischemic attacks, strokes, or myocardial infarctions. Two patients (3%), one CR (PRU, 240) and one responder (PRU, 119), experienced postoperative access site hematomas that required no subsequent intervention; no other index hospitalization hemorrhagic complications occurred.
Conclusion(s): Using preoperative P2Y12 testing with a threshold of PRU >=194 to define CR, we identified a high prevalence of CR in patients undergoing TCAR similar to that in the pre-existing coronary literature. We found no significant differences in postoperative ischemic or hemorrhagic complications by clopidogrel response phenotype, although complication rates in the overall study cohort were low. Further investigation is warranted to determine if a quantitative assessment of CR is sufficient to identify patients at risk of developing secondary cerebrovascular ischemic events in this patient population.
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Objectives: In patients with carotid stenosis, both the severity of the stenosis as well as the plaque morphology influence the likelihood of future transient ischemic attack or stroke. In general, severely stenotic lesions are presumed to have a higher embolic potential than moderately stenotic lesions. Carotid intervention is indicated in patients with both moderate and severe stenosis with related cerebrovascular symptoms. However, the effect of the degree of carotid stenosis in symptomatic patients upon the outcome of carotid intervention has not been extensively studied.
Method(s): The Society for Vascular Surgery Quality Initiative database was queried for all patients undergoing transfemoral carotid stenting (CAS), carotid endarterectomy (CEA), and transcervical carotid stenting (TCAR) between 2003 and 2020. Patients undergoing interventions for symptomatic disease were included in the analysis. Patients were stratified into two cohorts based on the severity of stenosis-moderate (0%-69%) and severe (greater than or equal to 70%). Primary endpoints were perioperative neurologic events (strokes and transient ischemic attacks [TIAs]). Secondary endpoints were perioperative mortality and postoperative complications.
Result(s): Over 50,000 patients were included in the analysis: 5296 patients (8.9%) underwent TCAR, 7844 (13.3%) underwent CAS, and 45,853 (77.8%) underwent CEA for symptomatic carotid artery disease. In the TCAR and CEA cohorts, patients with moderate stenosis had a significantly higher rate of perioperative neurologic events than patients with severe stenosis (TCAR 4.3% vs 3.0%; P =.033; CEA 3.0% vs 2.3%; P <.001). In contrast, in patients undergoing CAS, there was no significant difference noted in the perioperative neurologic event rate (3.5% in moderate stenosis group vs 3.8% in severe stenosis group; P =.518). There were no differences in perioperative myocardial infarction or mortality (Table). On multivariable analysis, moderate stenosis was significantly and independently associated with an increased rate of neurologic events in the TCAR (odds ratio [OR], 0.833; 95% confidence interval, 0.693-1.000; P =.05), and CEA (odds ratio, 0.901; 95% confidence interval, 0.861-0.944; P <.001) cohorts.
Conclusion(s): Moderate carotid stenosis was associated with increased perioperative neurologic events in patients undergoing TCAR and CEA, but not CAS. Therefore, this effect was noted only in the cohorts that require direct open surgical manipulation of the cervical carotid artery (TCAR and CEA). Moderately stenotic lesions that become symptomatic likely have worse intrinsic plaque morphology than severely stenotic lesions, producing cerebrovascular symptoms at a lower degree of stenosis. The mechanism of such events warrants further evaluation with a particular focus on plaque morphology and brain physiology. [Formula presented]
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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.