Considerations for the application of artificial intelligence in vascular surgical education.

The rapid adoption of artificial intelligence (AI) into everyday use has presented multiple issues for surgical educators to consider. In this article, the authors discuss some of the ethical aspects of academic integrity and the use of AI. These issues include the importance of understanding the current limits of AI and the inherent biases of the technology. The authors further discuss the ethical considerations of the use of AI in surgical training and in clinical use, with an emphasis on vascular surgery.

Efficacy and safety of single versus dual antiplatelet therapy in carotid artery stenting.

OBJECTIVE: Current guidelines recommend dual antiplatelet (AP) therapy (DAPT) before carotid artery stenting (CAS); however, the true clinical effect of single AP therapy vs DAPT is unknown. We examined the efficacy and safety of preoperative single AP therapy vs DAPT in patients who had undergone transfemoral CAS (tfCAS) or transcarotid artery revascularization (TCAR). METHODS: We identified all patients who had undergone tfCAS or TCAR in the Vascular Quality Initiative database from 2016 to 2021. We stratified the patients by procedure and identified those who had received the following preoperative AP regimens: DAPT (acetylsalicylic acid [ASA] + P2Y12 inhibitor [P2Yi]), no AP therapy, ASA only, ASA + AP loading dose, P2Yi only, and P2Yi + AP loading dose. The AP loading dose was given within 4 hours of CAS. We generated propensity scores for each treatment regimen and assessed in-hospital outcomes using inverse probability weighted log binomial regression, with DAPT as the reference and adjusting for intraoperative protamine use. The primary efficacy outcome was a composite end point of stroke and death, and the primary safety outcome was access-related bleeding. RESULTS: Of the 18,570 tfCAS patients, 70% had received DAPT, 5.6% no AP therapy, 10% ASA only, 8.0% ASA + AP loading dose, 4.6% P2Yi only, and 2.9% P2Yi + AP loading dose. The corresponding unadjusted rates of stroke/death were 2.2%, 6.8%, 4.1%, 5.1%, 2.4%, and 2.3%. After adjustment, compared with DAPT, the incidence of stroke/death was higher with no AP therapy (relative risk [RR], 2.3; 95% confidence interval [CI], 1.7-3.2), ASA only (RR, 1.6; 95% CI, 1.2-2.1), and ASA + AP loading dose (RR, 2.0; 95% CI, 1.5-2.7) but was similar with P2Yi only (RR, 0.99; 95% CI, 0.58-1.7) and P2Yi + AP loading dose (RR, 1.1; 95% CI, 0.49-2.5). Of the 25,459 TCAR patients, 81% had received DAPT, 2.0% no AP therapy, 5.5% ASA only, 3.5% ASA + AP loading dose, 4.9% P2Yi only, and 2.4% P2Yi + AP loading dose. The corresponding unadjusted rates of stroke/death were 1.5%, 3.3%, 3.3%, 2.9%, 1.2%, and 1.1%. After adjustment, compared with DAPT, the incidence of stroke/death was higher with no AP therapy (RR, 2.0; 95% CI, 1.2-3.3) and ASA only (RR, 2.2; 95% CI, 1.5-3.1), with a trend toward a higher incidence with ASA + AP loading dose (RR, 1.6; 95% CI, 0.99-2.6), and was similar with P2Yi only (RR, 0.98; 95% CI, 0.54-1.8) and P2Yi + AP loading dose (RR, 0.66; 95% CI, 0.27-1.6). No differences were found in the incidence of access-related bleeding between the treatment groups after tfCAS or TCAR. CONCLUSIONS: Compared with DAPT, no AP therapy or ASA monotherapy was associated with higher rates of stroke/death after CAS and should be discouraged as unsafe practice. Meanwhile, P2Yi monotherapy was associated with similar rates of stroke/death. No differences were found in the incidence of bleeding complications, and adding an AP loading dose to ASA or P2Yi monotherapy within 4 hours of the procedure did not affect the outcomes. Overall, these findings support the current guidelines recommending DAPT before CAS but also suggest that P2Yi monotherapy might confer thromboembolic benefits similar to those with DAPT. However, an immediate preoperative AP loading dose might not provide additional thromboembolic benefits.

One-year outcomes after transcarotid artery revascularization (TCAR) in the ROADSTER 2 trial.

OBJECTIVES: Transcarotid artery revascularization (TCAR) is a carotid stenting technique that utilizes reversal of cerebral arterial flow to confer cerebral protection. Although carotid endarterectomy (CEA) remains the standard for treatment of symptomatic and asymptomatic carotid stenosis, the search for the optimal minimally invasive option for the high-risk surgical patient continues. The goal of the current study is to evaluate the 1-year safety and efficacy of TCAR in a prospective clinical trial. METHODS: ROADSTER 2 is a prospective, open-label, single-arm, multicenter, post-approval registry for patients undergoing TCAR. All patients were considered high risk for CEA and underwent independent neurological assessments preoperatively, postoperatively, and had long-term clinical follow-up. The primary end point was incidence of ipsilateral stroke after treatment with the ENROUTE Transcarotid Stent System. Secondary end points included individual/composite rates of stroke, death, and perioperative myocardial infarction. RESULTS: Between June 2016 and November 2018, 155 patients at 21 centers in the United States and one in the European Union were enrolled and represented a subset of the overall trial. Asymptomatic (n = 119; 77%) and symptomatic patients (n = 36; 23%) with high-risk anatomic (ie, high lesion, restenosis, radiation injury; 43%), physiologic (32%), or combined factors (25%) were enrolled. No patient suffered a perioperative myocardial infarction or stroke. Over the year, no patient had an ipsilateral stroke, but four patients died (2.6%), all from non-neurological causes. Additionally, a technical success rate of 98.7% with a low cranial nerve deficit rate of 1.3% was achieved. CONCLUSIONS: In patients with high risk factors, TCAR yields high technical success with a low stroke and death rate at 1 year. Further comparative studies with CEA are warranted.

The Society for Vascular Surgery clinical practice guidelines on popliteal artery aneurysms.

The Society for Vascular Surgery clinical practice guidelines on popliteal artery aneurysms (PAAs) leverage the work of a panel of experts chosen by the Society for Vascular Surgery to review the current world literature as it applies to PAAs to extract the most salient, evidence-based recommendations for the treatment of these patients. These guidelines focus on PAA screening, indications for intervention, choice of repair strategy, management of asymptomatic and symptomatic PAAs (including those presenting with acute limb ischemia), and follow-up of both untreated and treated PAAs. They offer long-awaited evidence-based recommendations for physicians taking care of these patients.

Efficacy and safety of perioperative dual antiplatelet therapy with ticagrelor versus clopidogrel in carotid artery stenting.

BACKGROUND: Clopidogrel resistance is associated with increased periprocedural neurologic events after carotid artery stenting (CAS). Ticagrelor offers an improved resistance profile; however, its bleeding risk has not been assessed with CAS. Therefore, we examined the efficacy and safety of perioperative dual antiplatelet therapy with aspirin/ticagrelor vs aspirin/clopidogrel in patients undergoing transfemoral carotid artery stenting (tfCAS) or transcarotid artery revascularization (TCAR). METHODS: We identified all patients who underwent tfCAS or TCAR in the Vascular Quality Initiative registry from January 2016 to March 2021. We stratified patients by procedure and assessed outcomes using 1:3 propensity score-matched cohorts of patients who received perioperative aspirin/ticagrelor vs aspirin/clopidogrel. The primary efficacy outcome was a composite endpoint of in-hospital stroke/death, and the primary safety outcome was access-related bleeding. As a secondary analysis, we assessed these outcomes after stratifying each cohort by intraoperative protamine use. RESULTS: Among 17,731 tfCAS patients, 593 (3.3%) received aspirin/ticagrelor and 11,404 (64%) received aspirin/clopidogrel. For the 2065 matched patients, no significant differences were found in the composite endpoint of stroke/death (aspirin/ticagrelor, 4.1%; vs aspirin/clopidogrel, 2.6%; relative risk [RR],1.5; 95% confidence interval [CI], 0.88-2.7) or in the individual endpoints of stroke (2.9% vs 1.8%; RR, 1.6; 95% CI, 0.87-3.0) or death (1.7% vs 1.1%; RR, 1.6; 95% CI, 0.71-3.5). However, aspirin/ticagrelor was associated with a higher risk of bleeding (5.8% vs 2.8%; RR, 2.0; 95% CI, 1.2-3.2). In a subgroup analysis of 297 tfCAS patients (14%) who received intraoperative protamine, no differences remained in stroke/death (1.5% vs 3.9%; RR, 0.38; 95% CI, 0.05-3.0), and there was no longer a difference in bleeding (3.0% vs 2.6%; RR, 1.1; 95% CI, 0.24-5.5). Among 17,946 TCAR patients, 453 (2.5%) received aspirin/ticagrelor and 13,696 (76%) received aspirin/clopidogrel. For the 1618 matched patients, no differences were found in stroke/death (0.7% vs 1.4%; RR, 0.53; 95% CI, 0.16-1.8), stroke (0.2% vs 1.2%; RR, 0.20; 95% CI, 0.03-1.5), death (0.5% vs 0.2%; RR, 3.0; 95% CI, 0.42-21), or bleeding (1.2% vs 1.6%; RR, 0.75; 95% CI, 0.28-2.0). For the 1429 TCAR patients (88%) who received protamine, no differences were found in stroke/death (0.8% vs 1.2%; RR, 0.68; 95% CI, 0.20-2.4) or bleeding (0.6% vs 1.4%; RR, 0.39; 95% CI, 0.09-1.7). CONCLUSIONS: Compared with aspirin/clopidogrel, aspirin/ticagrelor was associated with a potentially lower risk of stroke/death and bleeding complications after CAS in cases in which protamine was used but a higher risk of these outcomes in the absence of protamine. Given our limited sample size, our analysis should be repeated when more patients are available for study. However, our findings suggest that aspirin/ticagrelor could be a reasonable alternative to aspirin/clopidogrel for both tfCAS and TCAR when protamine is used.

Contemporary Outcomes After Partial Resection of Infected Aortic Grafts.

INTRODUCTION: Aortic graft infection remains a considerable clinical challenge, and it is unclear which variables are associated with adverse outcomes among patients undergoing partial resection. METHODS: A retrospective, multi-institutional study of patients who underwent partial resection of infected aortic grafts from 2002 to 2014 was performed using a standard database. Baseline demographics, comorbidities, operative, and postoperative variables were recorded. The primary outcome was mortality. Descriptive statistics, Kaplan-Meier (KM) survival analysis, and Cox regression analysis were performed. RESULTS: One hundred fourteen patients at 22 medical centers in 6 countries underwent partial resection of an infected aortic graft. Seventy percent were men with median age 70 years. Ninety-seven percent had a history of open aortic bypass graft: 88 (77%) patients had infected aortobifemoral bypass, 18 (16%) had infected aortobiiliac bypass, and 1 (0.8%) had an infected thoracic graft. Infection was diagnosed at a median 4.3 years post-implant. All patients underwent partial resection followed by either extra-anatomic (47%) or in situ (53%) vascular reconstruction. Median follow-up period was 17 months (IQR 1, 50 months). Thirty-day mortality was 17.5%. The KM-estimated median survival from time of partial resection was 3.6 years. There was no significant survival difference between those undergoing in situ reconstruction or extra-anatomic bypass (P = 0.6). During follow up, 72% of repairs remained patent and 11% of patients underwent major amputation. On univariate Cox regression analysis, Candida infection was associated with increased risk of mortality (HR 2.4; P = 0.01) as well as aortoenteric fistula (HR 1.9, P = 0.03). Resection of a single graft limb only to resection of abdominal (graft main body) infection was associated with decreased risk of mortality (HR 0.57, P = 0.04), as well as those with American Society of Anesthesiologists classification less than 3 (HR 0.35, P = 0.04). Multivariate analysis did not reveal any factors significantly associated with mortality. Persistent early infection was noted in 26% of patients within 30 days postoperatively, and 39% of patients were found to have any post-repair infection during the follow-up period. Two patients (1.8%) were found to have a late reinfection without early persistent postoperative infection. Patients with any post-repair infection were older (67 vs. 60 years, P = 0.01) and less likely to have patent repairs during follow up (59% vs. 32%, P = 0.01). Patients with aortoenteric fistula had a higher rate of any post-repair infection (63% vs. 29%, P < 0.01) CONCLUSION: This large multi-center study suggests that patients who have undergone partial resection of infected aortic grafts may be at high risk of death or post-repair infection, especially older patients with abdominal infection not isolated to a single graft limb, or with Candida infection or aortoenteric fistula. Late reinfection correlated strongly with early persistent postoperative infection, raising concern for occult retained infected graft material.

Assessing the suitability of the carotid bifurcation for stenting: Anatomic and morphologic considerations.

OBJECTIVE: Over the years where stents have been used to treat carotid lesions, a great deal has been learned about which anatomic characteristics lead to adverse outcomes. This review summarizes the anatomic and morphologic characteristics of the carotid vasculature that can help guide patient selection and clinical decision-making. METHODS: Each of the carotid artery anatomy and lesion characteristics that are relevant to carotid stenting is described in detail. These are accompanied with evidence-based outcomes and results. RESULTS: Data on the prevalence of carotid artery lesions that are unsuitable for stenting are summarized and the implications of these data for practice are discussed, especially as they pertain to transcarotid artery revascularization. CONCLUSIONS: Carotid artery stenting can be a viable option for carotid revascularization, but the lesion must be acceptable and safe for stent placement. There should be thorough assessment to rule out the presence of severe tortuosity, long-segment disease, severe calcification (circumferential or exophytic), mobile plaque, swollen internal carotid artery sign, and carotid diameters outside the acceptable range. In carefully chosen lesions with the absence of the unfavorable characteristics described, transcarotid artery revascularization may offer improved periprocedural success and carotid artery stenting may attain better long-term durability.

In situ bypass and extra-anatomic bypass procedures result in similar survival in patients with secondary aortoenteric fistulas.

OBJECTIVE: The optimal revascularization modality in secondary aortoenteric fistula (SAEF) remains unclear in the literature. The purpose of this investigation was to determine the revascularization approach associated with the lowest morbidity and mortality using real-world data in patients with SAEF. METHODS: A retrospective, multi-institutional study of SAEF from 2002 to 2014 was performed using a standardized database. Baseline demographics, comorbidities, and operative and postoperative variables were recorded. The primary outcome was long-term mortality. Descriptive statistics, Kaplan-Meier survival analysis, and univariate and multivariate analyses were performed. RESULTS: During the study period, 182 patients at 34 institutions from 11 countries presented with SAEF (median age, 72 years; 79% male). The initial aortic procedures that resulted in SAEF were 138 surgical grafts (76%) and 42 endografts (23%), with 2 unknown; 102 of the SAEFs (56%) underwent complete excision of infected aortic graft material, followed by in situ (in-line) bypass (ISB), including antibiotic-soaked prosthetic graft (53), autogenous femoral vein (neoaortoiliac surgery; 17), cryopreserved allograft (28), and untreated prosthetic grafts (4). There were 80 patients (44%) who underwent extra-anatomic bypass (EAB) with infected graft excision. Overall median Kaplan-Meier estimated survival was 319 days (interquartile range, 20-2410 days). Stratified by EAB vs ISB, there was no significant difference in Kaplan-Meier estimated survival (P = .82). In comparing EAB vs ISB, EAB patients were older (74 vs 70 years; P = .01), had less operative hemorrhage (1200 mL vs 2000 mL; P = .04), were more likely to initiate dialysis within 30 days postoperatively (15% vs 5%; P = .02), and were less likely to experience aorta-related hemorrhage within 30 days postoperatively (3% aortic stump dehiscence vs 11% anastomotic rupture; P = .03). There were otherwise no significant differences in presentation, comorbidities, and intraoperative or postoperative variables. Multivariable Cox regression showed that the duration of antibiotic use (hazard ratio, 0.92; 95% confidence interval, 0.86-0.98; P = .01) and rifampin use at time of discharge (hazard ratio, 0.20; 95% confidence interval, 0.05-0.86; P = .03) independently decreased mortality. CONCLUSIONS: These data suggest that ISB does not offer a survival advantage compared with EAB and does not decrease the risk of postoperative aorta-related hemorrhage. After repair, <50% of SAEF patients survive 10 months. Each week of antibiotic use decreases mortality by 8%. Further study with risk modeling is imperative for this population.

Management of Seat Belt-type Blunt Abdominal Aortic Trauma and Associated Injuries in Pediatric Patients.

BACKGROUND: "Seat belt-type" pediatric abdominal aortic trauma is uncommon but potentially lethal. During high speed motor vehicle collisions (MVCs), seat or lap belt restraints may concentrate forces in a band-like pattern across the abdomen, resulting in the triad of hollow viscus perforation, spine fracture, and aortoiliac injury. We report 4 cases of pediatric seat belt-type aortic trauma and review management strategies for the aortic disruption and the associated constellation of injuries. METHODS: -approved, retrospective review of all pediatric patients requiring surgical intervention for seat belt-type constellation of abdominal aortic/iliac and associated injuries over a 5-year period. Blunt thoracic aortic injuries were excluded. RESULTS: We identified 4 patients, ranging from 2 to 17 years of age, who required surgical correction of seat belt-type aortoiliac trauma and associated injuries: 3 abdominal aortas and 1 left common iliac artery. The majority (3/4 patients) were hemodynamically unstable at emergency room presentation, and all underwent computed tomography angiography of the chest/abdomen/pelvis during initial resuscitation. Injuries of the suprarenal and proximal infrarenal aorta were accompanied by unilateral renal artery avulsion requiring nephrectomy. Presumed or proven spinal instability mandated supine positioning and midline laparotomy, with medial visceral rotation utilized for proximal injuries. Aortoiliac injuries requiring repair were accompanied by significant distal intraluminal prolapse of dissected intima, with varying degrees of obstruction. Conduit selection was dictated by the presence of enteric contamination and the rapid availability of an autologous conduit. The sole neurologic deficit was irreparable at presentation. CONCLUSIONS: Seat belt aortoiliac injuries in pediatric patients require prompt multidisciplinary evaluation. Evidence of contained aortoiliac transection, major branch vessel avulsion, and bowel perforation mandates immediate exploration, which generally precedes spinal interventions. Lesser degrees of aortoiliac injuries have been managed with surveillance, but long-term follow-up is needed to fully validate this approach.

The study of transcarotid artery revascularization under local versus general anesthesia with results from the Society for Vascular Surgery Vascular Quality Initiative.

OBJECTIVE: The primary purpose of this study was to examine any potential difference in clinical outcomes between transcarotid artery revascularization performed under local anesthesia compared with general anesthesia by utilizing a large national database. METHODS: The primary outcome of the study was a composite endpoint of postoperative in-hospital stroke, myocardial infarction and mortality following transcarotid artery revascularization for the index procedure. Secondary outcomes included a composite outcome of postoperative in-hospital stroke, transient ischemic attack, myocardial infarction and mortality along with several subsets of its components and each individual component, flow reversal time (min), radiation dose (GY/cm2), contrast volume utilized (mL), total procedure time (min), extended total length of stay (>1 day) and extended postoperative length of stay (>1 day). Statistical analyses employed both descriptive measures to characterize the study population and analytic measures such as multivariable mixed-effect linear and logistic regressions using both unmatched and propensity-score matched cohorts. RESULTS: A total of 2609 patients undergoing transcarotid artery revascularization between the years 2016 and 2018 in the US were identified, with 82.3% performed under general anesthesia and 17.7% under local anesthesia. The primary composite outcome was observed in 2.3% of general anesthesia patients versus 2.6% of local anesthesia patients (p = 0.808). The rate of postoperative transient ischemic attack and/or myocardial infarction was 1.6% with general anesthesia versus 1.1% with local anesthesia (p = 0.511). For adjusted regression analysis, general anesthesia and local anesthesia were comparable in terms of primary outcome (OR: 0.72; 95% CI: 0.27-1.93, p = 0.515). As for the secondary outcomes, no significant differences were found except for contrast, where the results demonstrated significantly less need for contrast with procedures performed under general anesthesia (coefficient: 4.94; 95% CI: 1.34-8.54, p = 0.007). A trend towards significance was observed for lower rate of postoperative transient ischemic attack and/or myocardial infarction (OR: 0.33; 95% CI: 0.09-1.18, p = 0.088) and lower flow reversal time under local anesthesia (coefficient: -0.94: 95% CI: -2.1-0.22, p = 0.111). CONCLUSIONS: Excellent outcomes from transcarotid artery revascularization for carotid stenosis were observed in the VQI database between the years 2016 and 2018, under both local anesthesia and general anesthesia. The data demonstrate the choice of anesthesia for transcarotid artery revascularization does not appear to have any effect on clinical outcomes. Surgical teams should perform transcarotid artery revascularization under the anesthesia type they are most comfortable with.

Trends of vascular surgery procedures in Marfan syndrome and Ehlers-Danlos syndrome.

OBJECTIVES: Marfan syndrome and Ehlers-Danlos syndrome represent two connective tissue vascular diseases requiring unique consideration in their vascular surgical care. A comprehensive national review encompassing all hospitalizations for the Marfan Syndrome and Ehlers-Danlos syndrome patient population is lacking. METHODS: The National (Nationwide) Inpatient Sample from 2010 to 2014 was reviewed for all inpatient vascular surgery procedures including those with a diagnosis of Marfan syndrome and Ehlers-Danlos syndrome. National estimates of vascular surgery rates were generated from provided weights. Patient demographics, procedure type, and outcomes were assessed. RESULTS: There were 3103 Marfan syndrome and 476 Ehlers-Danlos syndrome vascular procedures identified as well as 3,895,381 vascular procedures in the remainder of population (control group). The percent of aortic procedures from all vascular procedures in Marfan syndrome (23.5%) and Ehlers-Danlos syndrome (23.5%) were 2.5-fold higher than controls (9.1%), p < 0.0001. Open aortic aneurysm repair was also significantly greater in both Marfan syndrome (16.8%) and Ehlers-Danlos syndrome (11.2%) compared to controls (4.4%), p < 0.0001. Endovascular aortic repair (p < 0.2302) was similar among the groups. Marfan syndrome (7.7%) and Ehlers-Danlos syndrome (5.1%) had more thoracic endovascular aortic repair performed than controls (0.7%), p < 0.0001. Percutaneous procedures were fewer in Marfan syndrome (6.3%) than controls (31.3%) and Ehlers-Danlos syndrome (26.3%), p < 0.0001, while repair of peripheral arteries was greater in Marfan syndrome (5.9%) and Ehlers-Danlos syndrome (4.1%) than controls (1.5%), p < 0.0001. For total aortic procedures, the mean age of aortic procedures was 68.2 years in controls vs 45.8 years in Marfan syndrome and 55.3 years in Ehlers-Danlos syndrome, p < 0.0001. Marfan syndrome and Ehlers-Danlos syndrome had fewer comorbidities overall, while controls had significantly higher rates of coronary artery disease (controls 39.9% vs Marfan syndrome 8.3% and Ehlers-Danlos syndrome 13.0%, p < 0.0001), peripheral vascular disease (controls 34.5% vs Marfan syndrome 4.2% and Ehlers-Danlos syndrome 8.7%, p < 0.0001), and diabetes (controls 20.6% vs Marfan syndrome 6.6 and Ehlers-Danlos syndrome 4.4%, p < 0.0001). Marfan syndrome and Ehlers-Danlos syndrome had higher overall complication rate (65.5% and 52.2%) compared to controls (44.6%), p < 0.0001. Postoperative hemorrhage was more likely in Marfan syndrome (42.9%) and Ehlers-Danlos syndrome (39.1%) than controls (22.2%), p < 0.0001. Increased respiratory failure was noted in Marfan syndrome (20.2%) vs controls (10.7%) and Ehlers-Danlos syndrome (8.7%), p = .0003. Finally, length of stay was increased in Marfan syndrome 12.5 days vs Ehlers-Danlos syndrome 7.4 days and controls 7.2 days (p < 0.0001) as well as a higher median costs of index hospitalization in Marfan syndrome ($57,084 vs Ehlers-Danlos syndrome $22,032 and controls $26,520, p < 0.0001). CONCLUSIONS: Patients with Marfan syndrome and Ehlers-Danlos syndrome differ from other patients undergoing vascular surgical procedures, with a significantly higher proportion of aortic procedures including open aneurysm repair and thoracic endovascular aortic repair. While they are younger with fewer comorbidities, due to the unique pathogenesis of their underlying connective tissue disorder, there is an overall higher rate of procedural complications and increased length of stay and cost for Marfan syndrome patients undergoing aortic surgery.

Concomitant transcarotid artery revascularization and transcatheter aortic valve replacement.

Concomitant carotid artery disease and aortic valve disease is common. Whereas carotid stenosis does not appear to have an effect on outcomes of patients undergoing aortic valve replacement, the management of a patient with symptomatic carotid disease and severe aortic stenosis is challenging. The advent of minimally invasive endovascular techniques has provided less invasive and effective treatment options for these respective conditions. In this report, we describe two cases of patients successfully treated with concomitant transcatheter aortic valve replacement and transcarotid artery revascularization.

Duration of blood flow reversal during transcarotid artery revascularization does not affect outcome.

OBJECTIVE: Transcarotid artery revascularization (TCAR) has become an increasingly popular alternative for the treatment of carotid bifurcation stenosis. TCAR employs carotid blood flow reversal through an ex vivo common carotid artery to femoral vein shunt for neuroprotection during the placement and angioplasty of the carotid artery stent. There is a lack of data regarding an association between the duration of flow reversal and neurologic complications or other adverse events. We analyzed TCAR flow reversal time in relation to major adverse events. METHODS: There were 307 patients who underwent TCAR at four high-volume academic institutions. Patients were separated on the basis of the duration of carotid flow reversal as follows: group I, ≤8 minutes (n = 138); group II, 9-13 minutes (n = 105); group III, 14-20 minutes (n = 42); and group IV, >20 minutes (n = 22). Adverse events including stroke (assessed by a National Institute of Health Stroke Scale-certified examiner), myocardial infarction (MI), and death at discharge and 30 days were collected in all patients and were compared between groups using one-way analysis of variance and χ2 analysis. RESULTS: There were four strokes in the total cohort, yielding an overall stroke rate of 1.3%. All strokes were minor in nature; two were ipsilateral and two were contralateral. All patients demonstrated full recovery at 30 days. We found no significant difference in the stroke rate between any of the groups: I, 1.5% (2/138); II, 1.9% (2/105); III, 0% (0/42); and IV, 0% (0/22; P = .76). The four strokes occurred in patients with flow reversal time of 6, 7, 11, and 12 minutes. There was also no difference in the 30-day composite stroke/death or stroke/death/MI rates among the groups. CONCLUSIONS: The length of flow reversal during TCAR does not affect rates of stroke, MI, or death. These data suggest that operators should focus on the technical aspects of the procedure during flow reversal rather than on its duration.

The learning curve of transcarotid artery revascularization.

BACKGROUND: In the pivotal U.S. Food and Drug Administration approval trial, ROADSTER, transcarotid artery revascularization (TCAR) using the ENROUTE Transcarotid Neuroprotection System (Silk Road Medical Inc, Sunnyvale, Calif) was shown to have one of the lowest reported complication rates, not only for carotid artery stent placement, but also for any carotid intervention, including endarterectomy. The number of cases required for a surgeon to gain the proficiency to realize these outcomes has not been studied. Our objective was to determine the learning curve for vascular surgeons performing the TCAR procedure. We examined the effect of surgeon procedural experience on intraoperative data and postoperative outcome. METHODS: This retrospective review analyzed data from a prospectively maintained database of 188 consecutive patients from three large academic centers who underwent TCAR. Procedures were ordered chronologically for each surgeon and grouped into bins of five. Operative times and flow reversal times were analyzed by analysis of variance. Results led to comparison of surgeons' early experience (cases 1-15) with their later experience (cases 16-50). The primary outcome was postoperative stroke and death. RESULTS: The mean procedural time for all cases was 75.0 ± 23.8 minutes. When the procedural time of cases 1 through 15 (mean, 79.0 ± 28.3 minutes) were compared with cases 16 through 50 (mean, 71.8 ± 19.0 minutes), a significant difference was noted (P = .02). The mean flow reversal time was 10.6 ± 6.8 minutes. When flow reversal times were compared using analysis of variance testing, cases 1 through 15 were statistically similar and cases 11 through 50 were also similar, but the two groups differed from each other (P < .001). For flow reversal, cases 1 through 15 had mean reversal times of 13.3 ± 8.8 minutes compared with 8.5 ± 3.5 minutes for cases 16 through 50 (P < .001). Postoperative stroke rates were similar in the 1 through 15 and 16 through 50 case groups (2.4% vs 1.0%; P = .59), as were death rates (0.0% vs 1.0%; P > .99). The combined stroke/death rates were also comparable at 2.4% in the early cohort vs 1.9% in the late cohort (P > .99). CONCLUSIONS: There seems to be a relatively short learning curve for the TCAR procedure. After 15 cases, surgeons are able to reduce procedural decrease by 10% (from 79.0 to 71.8 minutes), and flow reversal times by an average of 40% (from 13.3 to 8.5 minutes). More important, the rates of stroke and death do not differ between early and late experience with TCAR. The TCAR procedure may be quickly and safely adopted by vascular surgeons for carotid intervention.

A multi-institutional analysis of transcarotid artery revascularization compared to carotid endarterectomy.

OBJECTIVE: Transcarotid artery revascularization (TCAR) is a novel approach to carotid intervention that uses a direct carotid cut-down approach coupled with cerebral blood flow reversal to minimize embolic potential. The initial positive data with TCAR indicates that it may be an attractive alternative to trans-femoral carotid artery stenting and possibly carotid endarterectomy (CEA) for high-risk patients. The purpose of this study was to present 30-day and 1-year outcomes after treatment by TCAR and to compare these outcomes against a matched control group undergoing CEA at the same institutions. METHODS: A retrospective review of all patients who underwent TCAR at four institutions between 2013 and 2017 was performed to evaluate the use of the ENROUTE Transcarotid Neuroprotection System (Silk Road Medical, Inc, Sunnyvale, Calif). TCAR patients had high-risk factors and were either enrolled in prospective trials or treated with a commercially available TCAR device after US Food and Drug Administration approval. Contemporaneous patients undergoing CEA at each institution were also reviewed. Patients were propensity matched in a 1:1 (CEA:TCAR) fashion with respect to preoperative comorbidities. Data were analyzed using statistical models with a P value of less than .05 considered significant. Individual and composite stroke, myocardial infarction, and death at 30 days and 1 year postoperatively were assessed. RESULTS: Consecutive patients undergoing TCAR or CEA were identified (n = 663) and compared. Patients undergoing the TCAR procedure (n = 292) had higher rates of diabetes (P = .01), hyperlipidemia (P = .02), coronary artery disease (P < .01), and renal insufficiency (P < .01) compared with unmatched CEA patients (n = 371). Stroke rates were similar at 30 days (1.0% TCAR vs 1.1% CEA) and 1 year (2.8% TCAR vs 3.0% CEA) in the unmatched groups. After propensity matching by baseline characteristics including gender, age, symptom status (36.3%, 35.3%) and diabetes, 292 TCAR patients were compared with 292 CEA patients. TCAR patients were more likely to be treated preoperative and postoperatively with clopidogrel (preoperatively, 82.2% vs 39.4% [P < .01]; postoperatively, 98.3% vs 36.0% [P < .01]) and statins (preoperatively, 88.0% vs 75.0% [P < .01]; postoperatively, 97.8% vs 78.8% [P < .01]). Stroke (1.0% TCAR vs 0.3% CEA; P = .62) and death (0.3% TCAR vs 0.7% CEA; P = NS) rates were similar at 30 days and comparable at 1 year (stroke, 2.8% vs 2.2% [P = .79]; death 1.8% vs 4.5% [P = .09]). The composite end point of stroke/death/myocardial infarction at 1 month postoperatively was 2.1% vs 1.7% (P = NS). TCAR was associated with a decreased rate of cranial nerve injury (0.3% vs 3.8%; P = .01). CONCLUSIONS: These early data suggest that patients undergoing TCAR, even those with high-risk comorbidities, achieve broadly similar outcomes compared with patients undergoing CEA while mitigating cranial nerve injury. Further comparative studies are warranted.

Use of an extracorporeal bypass for renal preservation to treat a rare case of a true mycotic aneurysm in a renal transplant patient.

True mycotic aneurysms of the abdominal aorta are extremely rare after organ transplantation. We report a renal transplant recipient who presented with Pseudomonas aeruginosa bacteremia and a new saccular infrarenal aortic aneurysm. A temporary extracorporeal axillofemoral bypass was placed to maintain perfusion to the transplant kidney. A contained rupture was found, and excision and in-line reconstruction were performed using a cryopreserved human aortic allograft. At 3 years, the patient remained well, with normal renal function while on oral antibiotic suppressive therapy. Use of an extracorporeal bypass was a viable technique with minimal morbidity for renal transplant preservation during open aortic replacement.

The effect of extremity vascular complications on the outcomes of cardiac support device recipients.

OBJECTIVE: To assess the effect of extremity vascular complications (EVCs, including ischemia or vessel trauma) on the outcomes of patients receiving cardiac support devices (CSDs, including ventricular assist device [VAD] and extracorporeal membrane oxygenation [ECMO]). METHODS: Institutional Review Board-approved, retrospective review of a prospectively maintained database of all temporary and permanent CSD recipients from 7/1/10 to 6/30/12. Patient demographics, procedural data, and outcomes were analyzed. The primary endpoint was all-cause mortality at 30-days post-CSD initiation. RESULTS: Of 208 patients who received CSDs, 31 (14.9%) experienced EVC: 13 (8.9%) of the 146 permanent VADs, 10 (26.3%) of the 38 temporary VADs, and 8 (33.3%) of the 24 ECMO patients. The 30-day mortality for CSD-EVC patients was not significantly higher than that of the CSD patients who did not experience EVC for permanent VAD (15.4% vs 4.5%; P = .15) and ECMO patients (50.0% vs 68.75%; P = 1.00), but was significantly higher for temporary VAD patients (80.0% vs 35.7%; P = .03). Within the CSD-EVC cohort, patients who received a temporary VAD had a significantly higher 30-day mortality and decision to withdraw care after EVC compared with those who received a permanent VAD (P = .01 and P < .01, respectively). Looking beyond the 30-day window, EVC was associated with higher mortality rates in the permanent VAD population (53.8% vs 25.6%; P = .025) but not the temporary VAD or ECMO groups. CONCLUSIONS: In temporary VAD recipients, EVCs result in higher 30-day mortality, more frequent withdrawal of care, and shortened survival time relative to the global temporary VAD group. EVC in permanent VAD recipients did not affect early (30-day) mortality rates, but strongly predicted a higher cumulative mortality risk for the 2-year study period. Overall ECMO mortality rates were high, and not significantly impacted by the occurrence of EVC. The nature of the EVC (cannulation site complication vs embolic injury) did not impact mortality. This data provides quality improvement targets for VAD programs.

The use of cryopreserved aortoiliac allograft for aortic reconstruction in the United States.

BACKGROUND: Aortic infections, even with treatment, have a high mortality and risk of recurrent infection and limb loss. Cryopreserved aortoiliac allograft (CAA) has been proposed for aortic reconstruction to improve outcomes in this high-risk population. METHODS: A multicenter study using a standardized database was performed at 14 of the 20 highest volume institutions that used CAA for aortic reconstruction in the setting of infection or those at high risk for prosthetic graft infection. RESULTS: Two hundred twenty patients (mean age, 65; male:female, 1.6/1) were treated since 2002 for culture positive aortic graft infection (60%), culture negative aortic graft infection (16%), enteric fistula/erosion (15%), infected pseudoaneurysm adjacent to the aortic graft (4%), and other (4%). Intraop cultures indicated infection in 66%. Distal anastomosis was to the femoral artery and iliac. Mean hospital length of stay was 24 days, and 30-day mortality was 9%. Complications occurred in 24% and included persistent sepsis (n = 17), CAA thrombosis (n = 9), CAA rupture (n = 8), recurrent CAA/aortic infection (n = 8), CAA pseudoaneurysm (n = 6), recurrence of aortoenteric fistula (n = 4), and compartment syndrome (n = 1). Patients with full graft excision had significantly better outcomes. Ten (5%) patients required allograft explant. Mean follow-up was 30 ± 3 months. Freedom from graft-related complications, graft explant, and limb loss was 80%, 88%, and 97%, respectively, at 5 years. Primary graft patency was 97% at 5 years, and patient survival was 75% at 1 year and 51% at 5 years. CONCLUSIONS: This largest study of CAA indicates that CAA allows aortic reconstruction in the setting of infection or those at high risk for infection with lower early and long-term morbidity and mortality than other previously reported treatment options. Repair with CAA is associated with low rates of aneurysm formation, recurrent infection, aortic blowout, and limb loss. We believe that CAA should be considered a first line treatment of aortic infections.

Gender-specific 30-day outcomes after carotid endarterectomy and carotid artery stenting in the Society for Vascular Surgery Vascular Registry.

OBJECTIVE: Although the optimal treatment of carotid stenosis remains unclear, available data suggest that women have higher risk of adverse events after carotid revascularization. We used data from the Society for Vascular Surgery Vascular Registry to determine the effect of gender on outcomes after carotid endarterectomy (CEA) and carotid artery stenting (CAS). METHODS: There were 9865 patients (40.6% women) who underwent CEA (n = 6492) and CAS (n = 3373). The primary end point was a composite of death, stroke, and myocardial infarction at 30 days. RESULTS: There was no difference in age and ethnicity between genders, but men were more likely to be symptomatic (41.6% vs 38.6%; P < .003). There was a higher prevalence of hypertension and chronic obstructive pulmonary disease in women, whereas men had a higher prevalence of coronary artery disease, history of myocardial infarction, and smoking history. For disease etiology in CAS, restenosis was more common in women (28.7% vs 19.7%; P < .0001), and radiation was higher in men (6.2% vs 2.6%; P < .0001). Comparing by gender, there were no statistically significant differences in the primary end point for CEA (women, 4.07%; men, 4.06%) or CAS (women, 6.69%; men, 6.80%). There remains no difference after stratification by symptomatology and multivariate risk adjustment. CONCLUSIONS: In this large, real-world analysis, women and men demonstrated similar results after CEA or CAS. These data suggest that, contrary to previous reports, women do not have a higher risk of adverse events after carotid revascularization.