The substantial burden of iatrogenic vascular injury on the vascular surgery workforce at an academic medical center.

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.

Generative artificial intelligence chatbots may provide appropriate informational responses to common vascular surgery questions by patients.

OBJECTIVES: 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: ChatGPT responses were rated, on average, more accurate than Bard responses (3.08 ± 0.33 vs 2.82 ± 0.40, p < .01). ChatGPT responses were scored, on average, more complete than Bard responses (2.98 ± 0.34 vs 2.62 ± 0.36, p < .01). Most ChatGPT responses (75.0%, n = 18) and almost half of Bard responses (45.8%, n = 11) were unanimously deemed appropriate. Almost one-third of Bard responses (29.2%, n = 7) were deemed inappropriate by at least two reviewers (29.2%), and two Bard responses (8.4%) were considered inappropriate by the majority. The mean Flesch Reading Ease, Flesch-Kincaid Grade Level, and Gunning Fog Index of ChatGPT responses were 29.4 ± 10.8, 14.5 ± 2.2, and 17.7 ± 3.1, respectively, indicating that responses were readable with a post-secondary education. Bard's mean readability scores were 58.9 ± 10.5, 8.2 ± 1.7, and 11.0 ± 2.0, respectively, indicating that responses were readable with a high-school education (p < .0001 for three metrics). ChatGPT's mean response length (332 ± 79 words) was higher than Bard's mean response length (183 ± 53 words, p < .001). There was no difference in the accuracy, completeness, readability, or response length of ChatGPT or Bard between disease domains (p > .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.

Short-term outcomes of endovascular management of acute limb ischemia using aspiration mechanical thrombectomy.

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: We identified 528 patients with Rutherford ALI Stage 1 or 2 who were treated with an endovascular adjunct. 433 patients did not undergo aspiration mechanical thrombectomy (no AMT group) and 95 patients did undergo aspiration mechanical thrombectomy (AMT group). The amputation-free survival across all patients was 93.4%. There were significant differences in demographic, comorbidity, and treatment variables between groups (e.g., gender, prior percutaneous coronary intervention (PCI), history of prior peripheral artery disease intervention, and history of prior infra-inguinal PVI), so a propensity score matched analysis was included to account for these group differences. In the propensity score matched analysis, there was no significant difference in major amputation (AMT 7.4% vs no AMT 3.2%, p = 0.13) or death (AMT 95.8% survival vs no AMT 98.4% survival, p = 0.23) with the use of aspiration mechanical thrombectomy. However, there was significantly worse amputation-free survival with the use of aspiration mechanical thrombectomy (AMT 88.4% vs no AMT 95.3%, p = 0.03). On multivariate analysis, prior supra-inguinal bypass (OR 4.85, 1.70-13.84, p = 0.003), Rutherford ALI Stage 2B (OR 3.13, 1.47-6.67, p = 0.003), and aspiration mechanical thrombectomy (OR 2.71, 1.03-7.17, p = 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.

Duplex ultrasound and cross-sectional imaging in carotid artery occlusion diagnosis.

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.

Natural history of internal carotid artery stenosis progression.

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.

Surgical management of recurrent and extra-adrenal pheochromocytomas requiring vascular resection and reconstruction.

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.

Abdominal aortic aneurysm neck dilatation and sac remodeling in fenestrated compared to standard endovascular aortic repair.

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: 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: 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.

Mannitol Use is Renal Protective in Patients with Chronic Kidney Disease Requiring Suprarenal Aortic Clamping.

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.

Fenestrated endovascular aortic aneurysm repair promotes positive infrarenal neck remodeling and greater sac shrinkage compared with endovascular aortic aneurysm repair.

OBJECTIVE: Endovascular aortic aneurysm repair (EVAR) has become the standard of care for abdominal aortic aneurysms (AAAs) in the modern era. Although numerous devices exist for standard infrarenal AAA repair, fenestrated EVAR (fEVAR) offers a minimally invasive alternative to traditional open repair for patients with a short infrarenal neck. Over time, aortic neck dilation can occur, leading to loss of the proximal seal, endoleaks, and AAA sac growth. In the present study, we analyzed aortic remodeling after EVAR vs fEVAR and further evaluated whether fEVAR confers a benefit in terms of sac shrinkage. METHODS: A retrospective review of prospectively collected data from 120 patients who had undergone EVAR was performed. Of these 120 patients, 30 had been treated with fEVAR (Zenith fenestrated; Cook Medical Inc, Bloomington, IN) and 90 patients were treated with EVAR devices (30 each with Endurant [Medtronic, Dublin, Ireland], Excluder [W.L. Gore & Associates, Flagstaff, AZ], and Zenith [Cook Medical Inc]). The demographic data were recorded. Also, anatomic measurements were performed for each patient preoperatively, at 30 days postoperatively, and at the longest follow-up point using three-dimensional reconstruction software. RESULTS: No significant differences were found in demographic data between the four groups. fEVAR had been used more often in aortas with large necks and irregular morphology (P = .004). At the longest follow-up, the suprarenal aorta encompassing 5, 10, and 15 mm above the lowest renal artery had dilated the most for the fEVAR group vs all EVAR groups. However, the infrarenal segment had tended to increase the least, or to even have regressed, for fEVAR compared with all three EVAR groups and was associated with the overall greatest proportion of sac shrinkage for the fEVAR group compared with the Medtronic, Gore, and Cook devices (-13.90% vs -5.75% vs -2.31% vs -4.68%, respectively; P = .025). CONCLUSIONS: Compared with EVAR, the patients treated with fEVAR had experienced greater suprarenal dilation over time, consistent with an overall greater burden of disease in the proximal native aorta. However, the infrarenal segment had dilated significantly less over time in the fEVAR group compared with all three EVAR groups, suggesting that fEVAR might stabilize the infrarenal neck, promoting positive sac remodeling, which was evidenced by the greatest degree of decrease in the largest AAA diameter in the fEVAR group.

Risk Factors for and Intraoperative Management of Intolerance to Flow Reversal in TCAR.

BACKGROUND: 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: A total of 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 intraoperative 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. 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 preexisting 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.

Low-frequency avoidable errors during transcarotid artery revascularization.

OBJECTIVE: Transcarotid artery revascularization (TCAR) seems to be a safe and effective alternative to carotid endarterectomy (CEA) and transfemoral carotid artery stenting (TF-CAS). The TCAR system represents a paradigm shift in the management of carotid artery stenosis with potential for a significant decrease in periprocedural morbidity. However, as with CEA or TF-CAS, TCAR is associated with infrequent complications related to user technical error, most of which are preventable. Our goal is to describe these low-frequency events, and to provide guidelines for avoiding them. METHODS: The U.S. Food and Drug Administration (FDA) requires that all medical device manufacturers create a system for receiving, reviewing, and evaluating complaints (Code 21 of Federal Regulations 820.198). Silk Road Medical, Inc (Sunnyvale, Calif), has established a process by which all feedback, including complaints that may not meet FDA criteria, is captured and stored in a database for detailed analysis. More than 13,300 cases have been performed; submitted complaints were reviewed for incidents of serious injury and periprocedural complications, above and beyond the device-related events that must be reported to the FDA. RESULTS: A total of 13,334 patients have undergone TCAR worldwide between early 2011 and December 2019 using the SilkRoad device. Reported complications included 173 dissections (1.4% overall rate) of the common carotid artery at the access point, of which 22.5% were managed without intervention or with medical therapy alone and 24.3% were converted to CEA (considered failing safely). Errors in the location of stent deployment occurred in 16 cases (0.13%), with the most common site being the external carotid artery (75%). One wrong side carotid artery stent was placed in a patient with a high midline pattern of the bovine arch. Cranial nerve injury was reported in 11 cases (0.08%), only one of which persisted beyond 3 months. There have been three reported pneumothoraces and one reported chylothorax. Many of these errors can be recognized and prevented with careful attention to detail. CONCLUSIONS: In high-risk patients requiring treatment for carotid artery stenosis, TCAR has been proven as an alternative to TF-CAS with an excellent safety profile. As with CEA or TF-CAS, this procedure has the potential for infrequent complications, often as a result of user technical error. Although significant, these events can be avoided through a review of the collective experience to date and recognition of potential pitfalls, as we have described.

Increased Dead Space Ventilation and Refractory Hypercapnia in Patients With Coronavirus Disease 2019: A Potential Marker of Thrombosis in the Pulmonary Vasculature.

OBJECTIVES: Mortality rates in intubated coronavirus disease 2019 patients remain markedly elevated. Some patients develop sudden refractory hypercapnia and hypoxemia not explained by worsening pulmonary parenchymal disease. This case series highlights clinical findings and management of coronavirus disease 2019 patients with refractory hypercapnia despite maximal/optimal ventilatory support. Hypercapnia could not be explained by worsening lung disease or other common factors, and thus, a pulmonary vascular etiology was suggested. The pillars of management were targeted to improve pulmonary vascular patency via aggressive anticoagulation and support right ventricular function. DATA SOURCES: Four consecutive patients with confirmed coronavirus disease 2019 infection with sudden hypercapnia and hypoxemia were included. DATA SYNTHESIS: There was sequential development of: 1) severe hypercapnia attributable to marked elevation of dead space without radiographic changes; 2) concomitant coagulopathy manifest by an increase in d-dimer levels; 3) progressive shunt with consequent hypoxemia; and 4) right ventricular dysfunction. Management included extracorporeal Co2 removal, direct thrombin inhibition, pulmonary vasodilators, and inotropic support. Marked improvement in Pao2 allowed reduction in Fio2 in all patients, extracorporeal Co2 removal was discontinued in three patients over the ensuing 3 weeks, and one patient was discharged home. CONCLUSIONS: We speculate that thromboinflammation with pulmonary microvasculature occlusion leads to a sudden increase in dead space and shunt resulting in severe hypercapnia and hypoxemia in coronavirus disease 2019 patients. Early identification of these physiologic and clinical biomarkers could trigger the institution of therapies aiming to reverse the hypercoagulable state and support right ventricular function.

Endovenous laser ablation: A comprehensive review.

OBJECTIVE: To provide an evidence-based overview of endovenous laser ablation and describe its role as an effective and durable technique for the management of superficial venous insufficiency. METHODS: The published literature on the treatment of varicose veins using endovenous laser ablation was reviewed. The literature search focused on the history of endovenous laser ablation, its safety and durability, known complications, and differences in outcomes based on the iterations of fiber type and laser wavelength. RESULTS: Treatment safety and efficacy of endovenous laser ablation appear to be based on the amount of energy administered over a defined distance, or the linear endovenous energy density. The ideal linear endovenous energy density varies with the laser wavelength and fiber-type. Post-operative pain and bruising may be reduced by the use of higher wavelength fibers or the use of radial or jacket-tip fibers as compared to bare-tip fibers. The incidence of endothermal heat-induced thrombosis remains low and has declined with increasing experience. Reports have demonstrated a greater than 90% technical success rate with saphenous endovenous laser ablation, long-term durability of ablation, and commensurate improvement in quality of life. CONCLUSIONS: Endovenous laser ablation is a safe and durable treatment option for the management of incompetent superficial and perforator veins of the lower extremities. As an endothermal technology, it remains a key component of the standard of care for the treatment of chronic venous insufficiency.

Presentation and Management of Inferior Vena Cava Thrombosis.

BACKGROUND: Inferior vena cava thrombosis (IVCT), although rare, has a potential for significant morbidity and mortality. IVCT is often a result of IVC filter thrombosis, but it can also occur de novo. Although anticoagulation remains the standard of care, endovascular techniques to restore IVC patency have become key adjunctive therapies in recent years. This study examines a single-center experience with diagnosis and management of IVCT. METHODS: A retrospective Institutional Review Board-approved review of a single-center institutional database was screened to identify IVCT thrombosis using International Classification of Diseases code 453.2 over a 3-year period. Etiology of IVCT was separated into 2 groups: those with IVC thrombosis in the setting of prior IVC filter place and those in whom IVCT occurred de novo. Patient demographics, presenting characteristics, and management of IVCT were examined. Treatment options included expectant management with anticoagulation versus catheter-directed thrombolysis (CDT), mechanical thrombectomy, stenting, or a combination. For those who underwent intervention, technical success, defined as restoration of IVC patency, was assessed. RESULTS: Forty-one unique patients were identified with radiographically confirmed diagnosis of ICVT (mean age 61, range 25-91; 21 female, 51.2%). Eighteen (43.9%) patients presented with thrombosed IVC filter. Risk factors for venous thromboembolism included tobacco usage, current or prior smoking (n = 17, 41.5%), history of prior deep vein thrombosis (n = 25, 61.0%), malignancy (n = 17, 41.5%), use of hormonal supplements (n = 3, 7.3%), known thrombophilia (n = 4, 9.8%), and obesity (body mass index: mean 29, range 18.8-58.53). Eleven patients (26.8%) presented with pulmonary embolism (PE), and of those 63.6% had IVC filter thrombosis (n = 7). Risk of PE was not significantly different between those patients presenting with a thrombosed IVC filter compared to those with de novo IVCT (38.9% vs. 17.4%, P = 0.12) Management of IVCT included anticoagulation alone (n = 27, 65.9%), CDT (n = 5, 12.2%), mechanical thrombolysis (n = 10, 24.4%), and adjunctive IVC stent (n = 3, 7.3%). Among the 14 (34.1%) patients who had intervention for IVCT, patency was restored in 12 patients (85.7%). CONCLUSIONS: IVCT is a rare event and is associated with known risk factors for venous thromboembolism. PE can occur in roughly 25% of patients presenting with IVCT. Presence of a filter does not appear to confer an advantage in preventing PE when IVCT occurs. Although majority of IVCT is managed with anticoagulation alone, endovascular interventions, including lysis and stenting, can safely restore patency in most properly selected patients.

A systematic review of venous aneurysms by anatomic location.

OBJECTIVE: Venous aneurysms are uncommon vascular abnormalities that may be identified anywhere in the body. Historically, they were often misdiagnosed as soft tissue lesions, but with the advent of readily available noninvasive imaging (such as duplex ultrasound), they can now be easily identified. Our aim was to review the presentation of venous aneurysms, available imaging modalities for defining them, and management. METHODS: The English-language literature before March 2017 was reviewed, and only reports of primary venous aneurysms of the deep veins were included. Reports were subdivided on the basis of the location of the venous aneurysm, and reports containing sample imaging studies were referenced from Elsevier publications. RESULTS: In total, our review identified reports of 35 head and neck venous aneurysms, 42 thoracic venous aneurysms, 152 intra-abdominal venous aneurysms, and 279 venous aneurysms of the extremities. Venous aneurysms of the lower extremity deep veins were most likely to be manifested by venous thromboembolic events, with approximately 25% to 50% of popliteal vein aneurysms presenting with pulmonary embolism. Diagnosis can be made by duplex ultrasound, computed tomography venography, magnetic resonance venography, or invasive venography. Management varies by location; most thoracic and head and neck aneurysms are observed, whereas venous aneurysms of the extremities are treated with surgical intervention, given the potential for venous thromboembolism. Few reports describe endovascular management of these lesions, so open surgical intervention remains the standard of care. CONCLUSIONS: Venous aneurysms are rare vascular malformations that occur throughout the body. Many are identified on routine imaging ordered for other indications, whereas venous aneurysms of the deep veins of the extremities are often manifested with venous thromboembolism. Management of these lesions is determined largely by location and the potential morbidity and mortality of the untreated aneurysms vs surgery; aneurysms of the head and neck and thorax are managed with observation and serial imaging over time, whereas those of the abdomen and extremities are treated with surgical intervention. Endovascular techniques continue to lack a defined role in their management, and the standard of care remains open repair, when indicated.

Why Temporary Filters Are Not Removed: Clinical Predictors in 1,000 Consecutive Cases.

BACKGROUND: Compared to permanent inferior vena cava (IVC) filters, higher complication rates occur with long-term use of temporary IVC filters. We aimed to identify patient clinical factors at the time of placement that could predict failure to remove a temporary IVC filter. METHODS: A retrospective review was performed of both vascular surgery and interventional radiology prospective databases between December 2008 and December 2013. We analyzed a total number of 1,024 consecutive, temporary IVC filters stratified by whether retrieval was attempted or made permanent. Univariate, multivariate, and prediction modeling analyses with internal validation were performed on abstracted data, which included risk factors, treatment modalities, and indications for IVC filter placement. RESULTS: Of 1,024 temporary IVC filters, removal was attempted in 60% and no attempt at removal (kept permanent) in 40%. Of the 619 with attempted removal, the overall successful retrieval rate was 95%. The majority of filters were not attempted to be removed because of persistent filter indications (360 cases). Risk factors associated with IVC filter permanence included male sex, older age, history, or indication of venous thromboembolism (VTE) with inability to anticoagulate, malignancy, and neurologic condition. Risk factors most predictive of permanence in the multivariate model were malignancy (odds ratio [OR]: 3.0, P < 0.001) or neurologic disorder (OR: 2.69, P = 0.0005). Validation revealed our model had a sensitivity of 60.4% and specificity of 69.9%. CONCLUSIONS: Our study shows that patients who are more likely to have a temporary IVC filter kept permanent are more likely to be older males with a history of malignancy, neurologic condition, or VTE. These factors are also predictive of permanence and can be used in our predictive model to provide insight into the significant preoperative risk factors that should play into the decision-making process.

Surveillance, anticoagulation, or filter in calf vein thrombosis.

OBJECTIVE: This study compared the efficacy and complication rates of inferior vena cava (IVC) filters for calf vein thrombosis (CVT) vs conservative treatment with or without anticoagulation. METHODS: Vascular laboratory studies of patients who had an isolated CVT (anterior and posterior tibialis, peroneal, soleal, and gastrocnemius veins) from April 2009 to January 2014 were retrospectively analyzed from a single institution. Of 647 patients with isolated CVT, 285 (44%) received an IVC filter, and 362 (56%) received medical treatment alone (38.9% surveillance, 11.6% prophylactic anticoagulation, and 49.4% therapeutic anticoagulation). Univariate, multivariate, propensity matching, and Kaplan-Meier analyses were performed on abstracted data, which included, but was not limited to, risk factors, treatment modalities, venous thromboembolism (VTE) complications (defined as propagation of deep vein thrombosis [DVT] or pulmonary embolism [PE]), bleeding complications, and IVC filter-related complications (ie, filter tilting >15°, perforation >3 mm, fracture, migration >10 mm). RESULTS: The overall incidence of PE in was 2.5% in the IVC filter group and 3.3% in the medical group (P = .27). The overall incidence of VTE complications (propagation of DVT, PE) was 35% for the surveillance group without anticoagulation, 30% in patients treated with prophylactic anticoagulation, and 10% in patients treated with therapeutic anticoagulation (P = .0003). Only a minority of patients underwent duplex ultrasound imaging after filter insertion. In the IVC filter group, the most common reasons that contraindicated anticoagulation were bleeding (35%) or recent surgery (27%). The number of IVC filter-related complications in the IVC filter group was 29 (10%). Because the IVC filter group was older (mean age, 65 vs 61 years, P = .004) and more likely to have a history of thromboembolic events (56% vs 16%, P < .0001), and malignancy (49% vs 28%, P < .0001), propensity analyses were performed yielding a homogenous cohort. The overall complication and thromboembolic rates did not differ for muscular (soleal, gastrocnemius) vs tibial DVTs (anterior, posterior, peroneal veins). CONCLUSIONS: The use of anticoagulation in patients with CVT significantly decreases the rates of VTE complications. The use of IVC filters in this study was associated with a 10% complication rate and did not significantly reduce the incidence of PE. Nevertheless, given the overall low rates of PE and the higher risk of VTE in patients who receive filters, the decision to insert a filter in patients with calf CVT should be individualized.

Determining If Sex Bias Exists in Human Surgical Clinical Research.

Importance: Sex is a variable that is poorly controlled for in clinical research. Objectives: To determine if sex bias exists in human surgical clinical research, to determine if data are reported and analyzed using sex as an independent variable, and to identify specialties in which the greatest and least sex biases exist. Design, Setting, and Participants: For this bibliometric analysis, data were abstracted from 1303 original peer-reviewed articles published from January 1, 2011, through December 31, 2012, in 5 surgery journals. Main Outcomes and Measures: Study type, location, number and sex of participants, degree of sex matching of included participants, and inclusion of sex-based reporting, statistical analysis, and discussion of data. Results: Of 2347 articles reviewed, 1668 (71.1%) included human participants. After excluding 365 articles, 1303 remained: 17 (1.3%) included males only, 41 (3.1%) included females only, 1020 (78.3%) included males and females, and 225 (17.3%) did not document the sex of the participants. Although female participants represent more than 50% (n = 57 688 606) of the total number (115 377 213) included, considerable variability existed with the number of male (46 111 818), female (58 805 665), and unspecified (10 459 730) participants included among the journals, between US domestic and international studies, and between single vs multicenter studies. For articles included in the study, 38.1% (497 of 1303) reported these data by sex, 33.2% (432 of 1303) analyzed these data by sex, and 22.9% (299 of 1303) included a discussion of sex-based results. Sex matching of the included participants in the research overall was poor, with 45.2% (589 of 1303) of the studies matching the inclusion of both sexes by 50%. During analysis of the different surgical specialties, a wide variation in sex-based inclusion, matching, and data reporting existed, with colorectal surgery having the best matching of male and female participants and cardiac surgery having the worst. Conclusions and Relevance: Sex bias exists in human surgical clinical research. Few studies included men and women equally, less than one-third performed data analysis by sex, and there was wide variation in inclusion and matching of the sexes among the specialties and the journals reviewed. Because clinical research is the foundation for evidence-based medicine, it is imperative that this disparity be addressed so that therapies benefit both sexes.