Faculty Bibliography

BACKGROUND:The effect of anticoagulation therapy (AC) on hemodialysis access patency and related complications is not well defined. Patients on long-term or chronic AC due to their underlying comorbid conditions may be particularly susceptible to access-related bleeding and complications from repetitive cannulation. Our goal is to assess the effect of anticoagulation therapy on outcomes after access creation. METHODS:The Vascular Quality Initiative (VQI) database was queried for patients undergoing arteriovenous fistula (AVF) or graft (AVG) placement, from 2011 to 2019. Only patients with data on post-procedural AC status were included. Anticoagulation use was defined as patients on warfarin, dabigatran, or rivaroxaban after access creation at postoperative follow up. Demographic and procedural details were analyzed. Wound infection and patency rates at six months were assessed. Binomial logistic regression analysis was performed to assess the association of anticoagulation use with these outcomes. RESULTS:A total of 27,757 patients underwent access creation, with the majority undergoing AVF creation (78.8%). The average age was 61.4 years and 55.3% were male. 12.9% of patients were on postoperative AC. The wound infection rate was 2.3- 3.8% in the no AC and AC cohorts, respectively (P < 0.001). At six months follow-up, patency was 85.7- 84.3% in the no AC and AC cohorts, respectively (P = 0.044). Expectedly, grafts had lower patency rates compared to AVF; those within the no AC cohort had a patency of 83.0% compared to 81.2 % in those on AC (P = 0.106). On multivariable analysis, anticoagulation use was associated with a higher risk of wound infections (odds ratio [OR] 1.513, 95% confidence interval [CI] 1.160-1.973, P = 0.002). AC use did not significantly affect access patency. CONCLUSION/CONCLUSIONS:Anticoagulation therapy was associated with a higher rate of wound infections but did not affect short-term access patency within six-months. These patients warrant close surveillance of their access for signs of infection. Furthermore, long-term implications of anticoagulation needs further evaluation.

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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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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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.

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.

The goal of the current review is to examine the hazards and benefits of carotid interventions in women and to provide recommendations for the indications for carotid intervention in female patients. Stroke and cerebrovascular disease are prevalent in women. There are inherent biological and other differences in men and women, which affect the manifestations and outcome of stroke, with women experiencing worse disability and higher mortality following ischemic stroke than men. Due to the underrepresentation of female patients in most clinical trials, the ability to make firm but alternative recommendations for women specifically on the management of carotid stenosis is challenging. Although some data suggest that women might have worse periprocedural outcomes as compared to men following all carotid revascularization procedures, there is also an abundance of data to support a similar risk for carotid procedures in men and women, especially with carotid endarterectomy and transcarotid artery revascularization. Therefore, the indications for carotid revascularization are the same in women as they are in men. The choice of a carotid revascularization procedure in women is based upon the same factors as in men and requires careful evaluation of a particular patient's risk profile, anatomic criteria, plaque morphology, and medical comorbidities that might favor one technique over the other. When performing carotid revascularization procedures in women, tailored techniques and procedures to address the small diameter of the female artery are warranted.

Management of carotid bifurcation stenosis in stroke prevention has been the subject of extensive investigations, including multiple randomized controlled trials. The proper treatment of patients with carotid bifurcation disease is of major interest to vascular surgeons and other vascular specialists. In 2011, the Society for Vascular Surgery published guidelines for the treatment of carotid artery disease. At the time, several randomized trials, comparing carotid endarterectomy (CEA) and carotid artery stenting (CAS), were reported. Since the 2011 guidelines, several studies and a few systematic reviews comparing CEA and CAS have been reported, and the role of medical management has been reemphasized. In the present publication, we have updated and expanded on the 2011 guidelines with specific emphasis on five areas: (1) is CEA recommended over maximal medical therapy for low-risk patients; (2) is CEA recommended over transfemoral CAS for low surgical risk patients with symptomatic carotid artery stenosis of >50%; (3) the timing of carotid intervention for patients presenting with acute stroke; (4) screening for carotid artery stenosis in asymptomatic patients; and (5) the optimal sequence of intervention for patients with combined carotid and coronary artery disease. A separate implementation document will address other important clinical issues in extracranial cerebrovascular disease. Recommendations are made using the GRADE (grades of recommendation assessment, development, and evaluation) approach, as was used for other Society for Vascular Surgery guidelines. The committee recommends CEA as the first-line treatment for symptomatic low-risk surgical patients with stenosis of 50% to 99% and asymptomatic patients with stenosis of 70% to 99%. The perioperative risk of stroke and death in asymptomatic patients must be <3% to ensure benefit for the patient. In patients with recent stable stroke (modified Rankin scale score, 0-2), carotid revascularization is considered appropriate for symptomatic patients with >50% stenosis and should be performed as soon as the patient is neurologically stable after 48 hours but definitely <14 days after symptom onset. In the general population, screening for clinically asymptomatic carotid artery stenosis in patients without cerebrovascular symptoms or significant risk factors for carotid artery disease is not recommended. In selected asymptomatic patients with an increased risk of carotid stenosis, we suggest screening for clinically asymptomatic carotid artery stenosis as long as the patients would potentially be fit for and willing to consider carotid intervention if significant stenosis is discovered. For patients with symptomatic carotid stenosis of 50% to 99%, who require both CEA and coronary artery bypass grafting, we suggest CEA before, or concomitant with, coronary artery bypass grafting to potentially reduce the risk of stroke and stroke/death. The sequencing of the intervention depends on the clinical presentation and institutional experience.

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.