Faculty Bibliography

OBJECTIVE:Vascular surgeons are often called upon to provide emergent surgical assistance to other specialties for iatrogenic complications, both intraoperatively and in the inpatient setting. The management of iatrogenic vascular injury remains a critical role of the vascular surgeon, especially in the context of the increasing adoption of percutaneous procedures by other specialties. This study aims to characterize consultation timing, management, and outcomes for iatrogenic vascular injuries. METHODS:This study identified patients for whom vascular surgery was consulted for iatrogenic vascular complications from February 1, 2022, to May 12, 2023. Patient information, including demographic information, injury details, and details of any operative intervention, was retrospectively collected from February 1, 2022, to October 13, 2022, and prospectively collected for the remainder of the study period. Analyses were performed with R (version 2022.02.03). RESULTS:There were 87 patients with consultations related to iatrogenic vascular injury. Of these, 42 (46%) were female and the mean age was 59 years (±18 years). The most common consulting services were cardiology (32%), cardiothoracic surgery (26%), general surgery (8%), and neurointerventional radiology (10%). Reasons for consultation included hemorrhage (36%), limb ischemia (36%), and treatment of pseudoaneurysm (23%). A total of 24% of consults were intraoperative, 20% of consults related to extracorporeal membrane oxygenation cannulation, and 16% of consults related to ventricular assist devices including left ventricular assist device and intra-aortic balloon pump. The majority of these consult requests (60%) occurred during evening and night hours (5 PM to 7 AM). Emergent intervention was required in 62% of cases and consisted of primary open surgical repair of arterial injury (54%), endovascular intervention (21%), and open thromboembolectomy (15%). Overall, in-hospital mortality for the patient cohort was 20% and the reintervention rate was 23%, reflecting the underlying complexity of the illness and nature of the vascular injury in this patient group. CONCLUSIONS:Vascular surgeons play an essential role in managing emergent life-threatening hemorrhagic and ischemic iatrogenic vascular complications in the hospitalized setting. The complications require immediate bedside or intraoperative consult and often emergent open surgical or endovascular intervention. Furthermore, many of these require urgent management in the evening or overnight hours, and therefore the high frequency of these events represents a potential significant resource utilization and workforce issue to the vascular surgery workforce.

OBJECTIVES/OBJECTIVE:Carotid interventions are indicated for both patients with symptomatic and a subset of patients with severe asymptomatic carotid artery stenosis (CAS). Symptomatic CAS accounts for up to 12%-25% of overall carotid interventions, but predictors of symptomatic presentation remain poorly defined. The aim of this study was to identify factors associated with symptomatic CAS in our patient population. METHODS:Between January 2015 and February 2022, an institutional retrospective cohort study of prospectively collected data on patients undergoing interventions for CAS was performed. Procedures included carotid endarterectomy (CEA), transcarotid artery revascularization (TCAR), and transfemoral carotid artery stenting (TF-CAS). Demographic data, comorbidities, procedural details, and anatomic features from various imaging modalities were collected. Comparisons were made between symptomatic (symptoms within the prior 6 months) and asymptomatic patients. RESULTS:< .001), and symptomatic patients with ulcerated plaques more frequently had less than 50% compared to moderate/severe CAS. Nine patients who presented with symptoms had mild CAS and underwent intervention. CONCLUSIONS:Symptomatic CAS was associated with a history of remote prior symptoms and lack of anti-platelet therapy at time of presentation. Furthermore, symptomatic patients not on anti-platelet agents were more likely to have a greater area of parenchymal involvement when presenting with stroke and symptomatic patients with ulcerated plaques were more likely to have mild CAS, suggesting the role of plaque instability in symptomatic presentation. These findings underscore the importance of appropriate medical management and adherence in all patients with CAS and perhaps a role for more frequent surveillance in those with potentially unstable plaque morphology.

OBJECTIVES/OBJECTIVE:Generative artificial intelligence (AI) has emerged as a promising tool to engage with patients. The objective of this study was to assess the quality of AI responses to common patient questions regarding vascular surgery disease processes. METHODS:OpenAI's ChatGPT-3.5 and Google Bard were queried with 24 mock patient questions spanning seven vascular surgery disease domains. Six experienced vascular surgery faculty at a tertiary academic center independently graded AI responses on their accuracy (rated 1-4 from completely inaccurate to completely accurate), completeness (rated 1-4 from totally incomplete to totally complete), and appropriateness (binary). Responses were also evaluated with three readability scales. RESULTS:> .05 for all analyses). CONCLUSIONS:AI offers a novel means of educating patients that avoids the inundation of information from "Dr Google" and the time barriers of physician-patient encounters. ChatGPT provides largely valid, though imperfect, responses to myriad patient questions at the expense of readability. While Bard responses are more readable and concise, their quality is poorer. Further research is warranted to better understand failure points for large language models in vascular surgery patient education.

OBJECTIVE:Investigations into imaging modalities in the diagnosis of extracranial carotid artery occlusion (CAO) have raised questions about the inter-modality comparability of duplex ultrasound (DUS) and cross-sectional imaging (CSI). This study examines the relationship between DUS and CSI diagnoses of extracranial CAO. METHODS:This single-institution retrospective analysis studied patients with CAO diagnosed by DUS from 2010 to 2021. Patients were identified in our office-based accredited vascular laboratory database. Imaging and clinical data was obtained via our institutional electronic medical record. Primary outcome was discrepancy between DUS and CSI modalities. Secondary outcomes included incidence of stroke and intervention subsequent to CAO diagnosis. RESULTS:Of our 140-patient cohort, 95 patients (67.9%) had DUS follow-up (mean, 42.7 ± 31.3 months). At index duplex, 68.0% of individuals (n = 51) were asymptomatic. Seventy-five patients (53.6%) had CSI of the carotids after DUS CAO diagnosis; 18 (24%) underwent magnetic resonance imaging and 57 (76%) underwent computed tomography. Indications for CSI included follow-up of DUS findings of carotid stenosis/occlusion (44%), stroke/transient ischemic attack (16%), other symptoms (12%), preoperative evaluation (2.7%), unrelated pathology follow-up (9.3%), and outside institution imaging with unavailable indications (16%). When comparing patients with CSI and those without, there were no differences with regard to symptoms at diagnosis, prior neck interventions, or hypertension. There was a significant difference between cross-sectionally imaged and non-imaged patients in anti-hypertensive medications (72% vs 53.8%; P = .04). Despite initial DUS diagnoses of carotid occlusion, 10 patients (13.3%) ultimately had CSI indicating patent carotids. Four of these 10 patients had stenoses of ∼99% (with 1 string sign), four of 70% to 99%, one of 50% to 69%, and one of less than 50% on CSI. The majority of patients (70%) had CSI within 1 month of the index ultrasound. There were no significant relationships between imaging discrepancies and body mass index, heart failure, upper body edema, carotid artery calcification, and neck hardware. Eight individuals (10.7%) underwent ipsilateral revascularization; 62.5% (n = 5) were carotid endarterectomy procedures, and the remaining three procedures were a transcervical carotid revascularization, subclavian to internal carotid artery bypass, and transfemoral carotid artery stenting. Eight patients (10.7%) underwent contralateral revascularization, with the same distribution of procedures as those ipsilateral to occlusions. Two of the 10 patients with discrepancies underwent carotid endarterectomy, and one underwent carotid stenting. CONCLUSIONS:In our experience, duplex diagnosis of CAO is associated with a greater than 10% discordance when compared with CSI. These patients may benefit from closer surveillance as well as confirmatory computed tomography or magnetic resonance angiography. Further work is needed to determine the optimal diagnostic modality for CAO.

OBJECTIVE:Management of acute limb ischemia (ALI) has seen greater utilization of catheter-based interventions over the last two decades. Data on their efficacy is largely based on comparisons of catheter-directed thrombolysis (CDT) and open thrombectomy. During this time, many adjuncts to CDT have emerged with different mechanisms of action, including pharmacomechanical thrombolysis (PMT) and aspiration mechanical thrombectomy (AMT). However, the safety and efficacy of newer adjuncts like AMT have not been well established. This study is a retrospective analysis of the contemporary management of ALI comparing patients treated with aspiration mechanical thrombectomy to patients treated with the more established CDT adjunct, pharmacomechanical thrombolysis. METHODS:Patients undergoing peripheral endovascular intervention for ALI using an adjunctive device were identified through query of the Vascular Quality Initiative (VQI) Peripheral Vascular Intervention (PVI) module from 2014 to 2019. Patients with a nonviable extremity (Rutherford ALI Stage 3), prior history of ipsilateral major amputation, popliteal aneurysm, procedures that were deemed elective (>72 h from admission), procedures that did not utilize an endovascular adjunctive device, and patients without short-term follow-up were all excluded from analysis. The primary outcome was a composite outcome of freedom from major amputation and/or death in the perioperative time period. RESULTS:= 0.05) were associated with the composite outcome. CONCLUSIONS:Short-term amputation-free survival rates of endovascular management of acute limb ischemia are adequate across all modalities. However, aspiration mechanical thrombectomy was associated with significantly worse amputation-free survival compared to other endovascular adjuncts alone (i.e., pharmacomechanical thrombolysis). Severe limb ischemia (Rutherford ALI Stage 2B) and prior supra-inguinal bypass were associated with worse amputation-free survival regardless of the choice of endovascular intervention.

OBJECTIVE:The aim of this study was to investigate the natural history of internal carotid artery (ICA) stenosis progression. METHODS:This single-institution retrospective cohort study analyzed patients diagnosed with ICA stenosis of 50% or greater on duplex ultrasound from 2015 to 2022. Subjects were drawn from our institutional Intersocietal Accreditation Commission-accredited noninterventional vascular laboratory database. Primary outcomes were incidences of disease progression, and stroke or revascularization after index study. Progression was defined as an increase in stenosis classification category. Imaging, demographic, and clinical data was obtained from our institutional electronic medical record via a database mining query. Cases were analyzed at the patient and artery levels, with severity corresponding to the greatest degree of ICA stenosis on index and follow-up studies. RESULTS:Of 577 arteries in 467 patients, mean cohort age was 73.5 ± 8.9 years at the time of the index study, and 45.0% (n = 210) were female. Patients were followed with duplex ultrasound for a mean of 42.2 ± 22.7 months. Of 577 arteries, 65.5% (n = 378) at the index imaging study had moderate (50%-69%) stenosis, 23.7% (n = 137) had severe (70%-99%) stenosis, and 10.7% (n = 62) were occluded. These three groups had significant differences in age, hypertension, hyperlipidemia prevalence, and proportion on best medical therapy. Of the 467-patient cohort, 56.5% (n = 264) were on best medical therapy, defined as smoking cessation, treatment with an antiplatelet agent, statin, and antihypertensive and glycemic agents as indicated. Mean time to progression for affected arteries was 28.0 ± 20.5 months. Of those arteries with nonocclusive disease at diagnosis, 21.3% (n = 123) progressed in their level of stenosis. Older age, diabetes, and a history of vasculitis were associated with stenosis progression, whereas antiplatelet agent use trended towards decreased progression rates. Of the 467 patients, 5.6% (n = 26) developed symptoms; of those, 38.5% (n = 10) had ischemic strokes, 26.9% (n = 7) had hemispheric transient ischemic attacks, 11.5% (n = 3) had amaurosis fugax, and 23.1% (n = 6) had other symptoms. A history of head and neck cancer was positively associated with symptom development. Of 577 affected arteries, 16.6% (n = 96) underwent intervention; 81% (n = 78) of interventions were for asymptomatic disease and 19% (n = 18) were for symptomatic disease. No patient-level factors were associated with risk of intervention. CONCLUSIONS:A significant number of carotid stenosis patients experience progression of disease. Physicians should consider long-term surveillance on all patients with carotid disease, with increased attention paid to those with risk factors for progression, particularly those with diabetes and a history of vasculitis.

This case series highlights that extra-adrenal and recurrent pheochromocytomas can require en bloc vascular resection to achieve negative margins. Through this series of cases performed in a multidisciplinary fashion, we aim to highlight the technical aspects of these cases that can add to their complexity. Vascular invasion alone should not preclude an otherwise feasible oncologic resection.

This case series highlights that extra-adrenal and recurrent pheochromocytomas can require en bloc vascular resection to achieve negative margins. Through this series of cases performed in a multidisciplinary fashion, we aim to highlight the technical aspects of these cases that can add to their complexity. Vascular invasion alone should not preclude an otherwise feasible oncologic resection.

BACKGROUND:Mannitol is often administered during open juxtarenal or suprarenal aortic surgery to prevent ischemic injury to the kidneys. Prior evidence evaluating the benefits of intraoperative mannitol in reducing ischemia/reperfusion injury is conflicting and largely based on small, retrospective series. The aim of this study was to evaluate the effect of mannitol in preventing postoperative hemodialysis in patients undergoing open abdominal aortic aneurysm (AAA) repair where proximal control involved temporary renal ischemia. METHODS:The Society for Vascular Surgery Quality Initiative database was queried for all patients undergoing elective open AAA repair between 2003 and 2020. Patients were included in the current analysis if the proximal aortic clamp was placed above at least one renal artery. Chronic kidney disease (CKD) was defined as Cr > 1.8 mg/dL. Primary end points were 30-day major morbidity (myocardial infarction, respiratory complications, lower extremity or intestinal ischemia, and the need for temporary or permanent hemodialysis) and mortality. Comparisons were made between the mannitol and nonmannitol cohorts and stratified by the presence of preexisting CKD. RESULTS:During the study period, 4,156 patients underwent elective open AAA repair requiring clamp placement more than one (32.7%) or both (67.3%) renal arteries; 182 patients (4.4%) had preexisting CKD. Overall, 69.8% of patients received mannitol during their surgery. Mannitol was more frequently used in cases involving clamp placement above both renal arteries (70.3%) than one renal artery (61.5%). While prolonged ischemia time (more than 40 min) was associated with a higher risk of postoperative dialysis in patients without CKD, it was not significant in patients with baseline CKD. On a univariate analysis, mannitol use in patients with CKD was associated with a lower risk of postoperative dialysis (P = 0.005). This remained significant on a multivariate analysis (P = 0.008). Mannitol use did not appear to confer renal protective effects in patients without baseline CKD. CONCLUSIONS:Mannitol use was associated with a decreased risk of need for postoperative hemodialysis in patients with CKD undergoing suprarenal aortic clamping for open aneurysm repair. In appropriately selected patients, particularly those with underlying renal insufficiency, mannitol may confer a renal protective effect in open repair of pararenal AAA requiring suprarenal clamping.

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.