Three-Year Results of the Endurant Stent Graft System Post Approval Study.

BACKGROUND: Long-term data following endovascular aneurysm repair (EVAR) exist but are limited to endografts that are no longer in use. The aim of the ENGAGE Post Approval Study is to describe the long-term safety and effectiveness data following EVAR using the Endurant stent graft system. METHODS: From August 2011 to June 2012, 178 patients were enrolled and treated with the Endurant stent graft system. Clinical and radiologic data were prospectively collected and analyzed. The primary end point was abdominal aortic aneurysm (AAA)-related mortality, and secondary end points were overall mortality, endoleak, secondary interventions, and device-related complications. Kaplan-Meier estimates were used for late outcomes. RESULTS: A total of 178 patients underwent EVAR with the Endurant stent graft across 24 centers (82% men; median age 71, interquartile range [IQR] 66-79). Median aortic diameter was 55 mm (IQR 51-58 mm). There was a 98.9% technical success rate. Three-year clinical and radiographic follow-up data were available for 87% and 74% of patients, respectively. Median follow-up was 37 months (IQR 30-38 months). Three-year aneurysm-related mortality rate was 1.1%, with 2 deceased patients in the perioperative period. All-cause mortality rate at 3 years was 13%. No patients suffered from aneurysm rupture or underwent conversion to open repair through 3 years of follow-up. Only 11 patients (6.2%) had undergone reintervention at 3 years. Younger age was associated with reintervention (HR 3.3 per younger decade, 95% confidence interval 1.3-7.6, P < 0.01), but neck diameter, length, and angulation were not significantly associated with reintervention. CONCLUSIONS: The Endurant stent graft system provides a safe, durable approach to treating infrarenal AAA. No patients experienced late rupture or aneurysm-related mortality, and only 1 in 16 patients underwent reintervention by 3 years. The rate of reintervention with the Endurant graft appears to be lower than other contemporary grafts, despite more liberal "Instructions For Use" parameters, but further research including direct graft comparisons will be necessary to guide appropriate graft selection.

Outcomes after first-time lower extremity revascularization for chronic limb-threatening ischemia between patients with and without diabetes.

OBJECTIVE: The effect of diabetes type and insulin dependence on short- and long-term outcomes after lower extremity revascularization for chronic limb-threatening ischemia (CLTI) warrants additional study and more targeted focus. We sought to address this paucity of information by evaluating outcomes in insulin-dependent and noninsulin-dependent patients after any first-time revascularization. METHODS: We reviewed all limbs undergoing first-time infrainguinal bypass grafting (BPG) or percutaneous transluminal angioplasty with or without stenting (PTA/S) for CLTI at our institution from 2005 to 2014. Based on preoperative medication regimen, patients were categorized as having insulin-dependent diabetes (IDDM), noninsulin-dependent diabetes (NIDDM), or no diabetes (NDM). Outcomes included wound healing; major amputation; RAS events (reintervention, major amputation, or stenosis); major adverse limb events; and mortality. Outcomes were evaluated using χ2, Kaplan-Meier, and Cox regression analyses. RESULTS: Of 2869 infrainguinal revascularizations from 2005 to 2014, 1294 limbs (646 BPG, 648 PTA/S) fit our criteria. Overall, our analysis included 703 IDDM, 262 NIDDM, and 329 NDM limbs. IDDM patients, compared with NIDDM and NDM patients, were younger (69 vs 73 vs 77 years; P < .001) and more often presented with tissue loss (89% vs 77% vs 67%; P < .001), coronary artery disease (57% vs 48% vs 43%; P < .001), and end-stage renal disease (26% vs 13% vs 12%; P < .001). Perioperative complications, including mortality (3% vs 2% vs 5%; P = .07), did not differ between groups; however, complete wound healing at 6-month follow-up was significantly worse among IDDM patients (41% vs 49% vs 61%; P < .001). IDDM patients had significantly higher 3-year major amputation rates (23% vs 11% vs 8%; P < .001). Multivariable analyses illustrated that compared with NDM, IDDM was associated with significantly higher risk of both major amputation and RAS events after any first-time intervention (hazard ratio, 2.0 [95% confidence interval, 1.1-4.1] and 1.4 [1.1-1.8], respectively). Similar associations between IDDM and both major amputation and RAS events were found in patients undergoing a PTA/S-first intervention (4.1 [1.3-12.6] and 1.5 [1.1-2.2], respectively), whereas IDDM in BPG-first patients was associated with only incomplete wound healing (2.0 [1.4-4.5]). Last, compared with NDM, NIDDM was associated with lower late mortality (0.7 [0.5-0.9]). CONCLUSIONS: Compared with NDM, IDDM is associated with similar perioperative and long-term mortality but a higher risk of incomplete wound healing, major amputation, and future RAS events, especially after a PTA/S-first approach. NIDDM, on the other hand, is associated with lower long-term mortality and few adverse limb events. Overall, these data demonstrate both the importance of distinguishing between diabetes types and the potential long-term benefit of a BPG-first strategy in appropriately selected IDDM patients with CLTI.

Early reintervention after open and endovascular abdominal aortic aneurysm repair is associated with high mortality.

OBJECTIVE: Although reinterventions are generally considered more common after endovascular aneurysm repair (EVAR) than after open surgical repair (OSR), less is known about reintervention in the early postoperative period. Furthermore, there are few data regarding the impact of early reintervention on 30-day mortality. We sought to evaluate the rates and types of reintervention after abdominal aortic aneurysm (AAA) repair and the impact of reintervention on postoperative mortality. METHODS: The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) was queried from 2012 to 2014 for all intact, infrarenal AAA repairs. The 30-day reintervention was classified by Current Procedural Terminology (CPT) codes. Univariate analysis comparing patients with and without reintervention was performed with the Fisher exact test and Mann-Whitney U test. Logistic regression was used to identify predictors of reintervention and to assess the association between 30-day reintervention and mortality. RESULTS: We identified 5877 patients (OSR, 658 [11%]; EVAR, 5219 [89%]), of whom 261 underwent reintervention (OSR, 7.1%; EVAR, 4.1%; P < .01). Patients who underwent reintervention had larger aortic diameter (median, 5.7 cm vs 5.5 cm; P < .01), were more often symptomatic at presentation (16% vs 9.1%; P < .01), and were more likely to have renal insufficiency (7.7% vs 3.6%; P < .01) and history of prior abdominal operations (32% vs 26%; P = .04). Patients who underwent reintervention had higher 30-day mortality (OSR, 28% vs 2.8% [P < .001]; EVAR, 12% vs 1.0% [P < .001]) and major complications. Factors significantly associated with reintervention included open repair, diameter, symptom status, hypertension, and renal insufficiency. After adjusting for demographics, comorbidities, and type of repair, reintervention was independently associated with 30-day mortality after EVAR and OSR (odds ratio, 13; 95% confidence interval, 8-22; P < .001). CONCLUSIONS: Compared with EVAR, patients undergoing open infrarenal AAA repair were significantly more likely to undergo 30-day reintervention, which could be related to higher open anatomic complexity and lower experience of the surgeon with open repair. Reintervention after both EVAR and OSR was associated with a >10-fold increase in postoperative mortality, emphasizing the need to minimize the complications associated with reintervention.

A preoperative risk score for transfusion in infrarenal endovascular aneurysm repair to avoid type and cross.

OBJECTIVE: Preoperative type and cross are often routinely ordered before elective endovascular aneurysm repair (EVAR), but the cost of this practice is high, and transfusion is rare. We therefore aimed to stratify patients by their risk of transfusion to identify a cohort in whom a type and screen would be sufficient. METHODS: We queried the targeted vascular module of the National Surgical Quality Improvement Program (NSQIP) for all elective EVARs from 2011 to 2015. We included only infrarenal aneurysms and excluded ruptured aneurysms and patients transfused within 72 hours preoperatively. Two-thirds of the cases were randomly assigned to a model derivation cohort and one third to a validation cohort. We created and subsequently validated a risk model for transfusion within the first 24 hours of surgery (including intraoperatively), using logistic regression. RESULTS: Between 2011 and 2015, there were 4875 patients who underwent elective infrarenal EVAR, only 221 (4.5%) of whom received a transfusion within 24 hours of surgery. The frequency of transfusion during the study period declined monotonously from 6.5% in 2011 to 3.2% in 2015. The factors independently associated with transfusion were preoperative hematocrit <36% (odds ratio [OR], 3.4 [95% confidence interval, 2.1-5.4]; P < .001), aortic diameter (per centimeter increase: OR, 1.2 [1.03-1.4]; P = .02), preoperative dependent functional status (OR, 2.5 [1.1-5.5]; P = .03), and chronic obstructive pulmonary disease (OR, 1.7 [1.04-2.9]; P = .04). A risk prediction model based on these criteria produced a C statistic of 0.69 in the prediction cohort and 0.76 in the validation cohort and a Hosmer-Lemeshow goodness of fit of 0.62 and 0.14, respectively. A score of <3 of 9, corresponding to a <5% probability of transfusion, would avoid preoperative type and cross in 86% of patients. Of the 4203 patients (86%) with a hematocrit >36%, only 6 (0.1%) had a risk score of >3. CONCLUSIONS: Perioperative transfusion for EVAR is becoming increasingly uncommon and is predicted well by a transfusion risk score or simply a hematocrit of <36%. Application of this risk score would avoid unnecessary type and cross in the majority of patients, leading to significant savings in both time and cost.

Patient selection and perioperative outcomes of bypass and endovascular intervention as first revascularization strategy for infrainguinal arterial disease.

OBJECTIVE: The optimal initial revascularization strategy remains uncertain for patients with peripheral arterial disease. The purpose of this study was to evaluate current nationwide selection and perioperative outcomes of patients undergoing bypass or endovascular intervention for infrainguinal disease in those with no prior ipsilateral revascularization. METHODS: Patients undergoing nonemergent first-time infrainguinal revascularization were identified in the Targeted Vascular module of the National Surgical Quality Improvement Program (NSQIP) for 2011 to 2014 and stratified by symptom status (chronic limb-threatening ischemia [CLTI] or claudication). Patients treated with endovascular intervention were compared with those who underwent bypass. Multivariable logistic regression was used to evaluate current selection of patients and to establish independent associations between first-time procedures and postoperative outcomes. RESULTS: Of 5998 first-time infrainguinal revascularizations performed, 3193 were bypass procedures (63% for CLTI) and 2805 were endovascular interventions (64% for CLTI). Current patient characteristics associated with an endovascular-first approach as opposed to bypass-first in CLTI patients were age ≥80 years, tissue loss, nonsmoking, functional dependence, diabetes, dialysis, and tibial lesions, whereas age ≥80 years, nonwhite race, nonsmoking, diabetes, and tibial lesions were associated with an endovascular approach for claudication. In comparing first-time endovascular intervention with bypass, there was no difference in 30-day mortality in CLTI patients (univariate: 2.1% vs 2.2%; adjusted: odds ratio [OR], 0.7; 95% confidence interval [CI], 0.4-1.1) or claudication patients (0.3% vs 0.6%). Among CLTI patients, endovascular-first intervention was associated with lower rates of major adverse cardiovascular event (3.6% vs 4.7%; OR, 0.6; 95% CI, 0.4-0.9), surgical site infection (0.9% vs 7.7%; OR, 0.1; 95% CI, 0.1-0.2), bleeding (8.5% vs 17%; OR, 0.4; 95% CI, 0.3-0.5), unplanned reoperation (13% vs 17%; OR, 0.7; 95% CI, 0.5-0.8), and unplanned readmission (17% vs 18%; OR, 0.8; 95% CI, 0.7-0.9). Patients with claudication undergoing endovascular-first intervention also had lower rates of major adverse cardiovascular event (0.8% vs 1.6%; OR, 0.4; 95% CI, 0.2-0.95), surgical site infection (0.7% vs 6.6%; OR, 0.1; 95% CI, 0.04-0.2), bleeding (2.3% vs 6.0%; OR, 0.3; 95% CI, 0.2-0.5), unplanned reoperation (4.3% vs 6.6%; OR, 0.6; 95% CI, 0.4-0.9), and unplanned readmission (5.9% vs 9.0%; OR, 0.6; 95% CI, 0.4-0.8). Conversely, endovascular-first intervention was associated with a higher rate of secondary revascularizations within 30 days for CLTI (4.3% vs 3.1%; OR, 1.6; 95% CI, 1.04-2.3) but not for claudication (2.6% vs 1.9%; OR, 1.7; 95% CI, 0.9-3.4). CONCLUSIONS: An endovascular-first approach as a revascularization strategy for infrainguinal disease was associated with substantially lower early morbidity but not mortality, at the cost of higher rates of postoperative secondary revascularizations. As a national representation of first-time revascularizations, this study highlights the early endovascular perioperative benefit, although more robust long-term data are needed to adopt either one strategy or the other in select patients with peripheral arterial disease.

Preoperative anemia is associated with mortality after carotid endarterectomy in symptomatic patients.

OBJECTIVE: Preoperative anemia and blood transfusions are associated with worse outcomes after surgery. However, the impact of preoperative anemia and transfusions on outcomes after carotid endarterectomy (CEA) is unknown. METHODS: CEA patients from 2011 to 2015 in the American College of Surgeons National Surgical Quality Improvement Program Targeted Vascular module were compared by the presence of preoperative anemia (hematocrit <36%) after stratification by symptom status. Multivariable analysis accounted for differences in baseline characteristics. We included an interaction term in our multivariable model to assess whether the effect of anemia differed significantly between patients who received a perioperative transfusion and those who did not, with 30-day mortality as our primary outcome. RESULTS: Of 16,068 patients, 6734 (42%) were symptomatic, of whom 1500 (22%) had anemia. Of the 9334 asymptomatic patients, 1935 (21%) had anemia. Both symptomatic and asymptomatic anemic patients were more likely to be transfused perioperatively compared with nonanemic patients, with 7.0% vs 0.4%, and 5.8% vs 0.7% (both P < .001). Among symptomatic patients, those with anemia compared with those without had a higher rate of 30-day mortality (2.5% vs 0.7%; P < .001). After adjustment, anemic symptomatic patients had a higher 30-day mortality risk (odds ratio [OR], 3.1; 95% confidence interval [CI], 1.9-5.0; P < .001) compared with nonanemic symptomatic patients. In addition, in symptomatic patients, we found a significant interaction between anemia and perioperative transfusion on the outcome of 30-day mortality (P = .004), with a higher risk in perioperatively transfused symptomatic patients with anemia (OR, 7.8; 95% CI, 3.4-18.0; P < .001) than in symptomatic patients with anemia who did not receive a perioperative transfusion (OR, 2.3; 95% CI, 1.4-3.9; P = .002). In asymptomatic patients, anemic and nonanemic patients had comparable 30-day mortality rates (0.9% vs 0.6%; P = .2). After adjustment, anemia was not associated with 30-day mortality in asymptomatic patients (OR, 1.0; 95% CI, 0.5-2.0; P = .9), nor did we identify an interaction between anemia and perioperative transfusion in asymptomatic patients (P = .1). Patients who received a preoperative transfusion had a higher 30-day mortality rate than anemic patients not receiving preoperative transfusion in both symptomatic (n = 31, 9.7% vs 2.5%; P = .04) and asymptomatic patients (n = 21, 9.5% vs 0.9%; P = .02). CONCLUSIONS: Preoperative anemia is a risk factor for 30-day mortality after CEA in symptomatic patients but not in asymptomatic patients. These results should be factored into the selection of symptomatic patients for CEA and dissuade treatment of asymptomatic patients scheduled for CEA who need a preoperative transfusion.

Long-term mortality benefit of renin-angiotensin system inhibitors in patients with chronic limb-threatening ischemia undergoing vascular intervention.

OBJECTIVE: The beneficial effect of renin-angiotensin system (RAS) inhibitors has been well-established in patients with cardiovascular disease; however, their effectiveness in patients with chronic limb-threatening ischemia (CLTI), a selected disease-burdened population, is largely unknown. The purpose of this study was to evaluate long-term outcomes of RAS inhibitor use in patients with CLTI undergoing a vascular intervention. METHODS: For this study, all patients with CLTI undergoing a first-time revascularization (bypass or endovascular) were analyzed at our institution between 2005 and 2014. Patients discharged on an RAS inhibitor (angiotensin-converting enzyme inhibitor or angiotensin receptor blocker) were compared with those not on an RAS inhibitor. The inverse probability of treatment weighting with additional regression analyses were used to determine the long-term risk of mortality and major adverse events. A sensitivity analysis was performed to assess the dose-related therapeutic response of RAS inhibitors (low-dose vs high-dose therapy). RESULTS: Between 2005 and 2014, 1303 limbs from 1161 patients were identified. Of these patients, 52% were discharged on an RAS inhibitor, with 67% discharged on a high-dose therapy and 33% on a low-dose therapy. Patients discharged on an RAS inhibitor suffered more frequently from diabetes, hypertension, and myocardial infarction, whereas those not on an RAS inhibitor had more chronic kidney disease (all P < .05). There was no difference in the proportion of patients presenting with tissue loss. After adjustment for these and other baseline covariates, RAS inhibitor use was associated with less late mortality (hazard ratio [HR], 0.78; 95% confidence interval [CI], 0.65-0.94). Discharge on a high-dose RAS inhibitor was associated with lower mortality (HR, 0.70; 95% CI, 0.57-0.86), whereas a low-dose RAS inhibitor was not associated with less mortality (HR, 0.95; 95% CI, 0.73-1.24) compared with patients not prescribed an RAS inhibitor. This association remained significant when comparing high-dose with low-dose therapy (HR, 0.74; 95% CI, 0.55-0.98). No associations were found between RAS inhibitor use and major adverse limb event (HR, 0.95; 95% CI, 0.73-1.22), major amputation (HR, 0.82; 95% CI, 0.57-1.18), or reintervention (HR, 1.05; 95% CI, 0.85-1.31). These point estimates were not different for those on angiotensin-converting enzyme inhibitors vs angiotensin receptor blockers, nor were they affected by the type of revascularization. CONCLUSIONS: Patients with CLTI prescribed an RAS inhibitor at discharge demonstrated significantly less long-term mortality, whereas limb events were unaffected. These data indicate that, in these heavily burdened patients, the benefit is restricted to those on a high dose, which underscores the importance of attaining these doses.

Preoperative anemia associated with adverse outcomes after infrainguinal bypass surgery in patients with chronic limb-threatening ischemia.

OBJECTIVE: Preoperative anemia in elderly patients undergoing surgery is prevalent and associated with adverse events; however, the interaction with other risk factors in patients with chronic limb-threatening ischemia (CLTI) is not well described. The purpose of this study was to assess the association between lower hematocrit (HCT) levels on admission and postoperative outcomes after infrainguinal bypass surgery. METHODS: Patients with CLTI undergoing nonemergent infrainguinal bypass were identified in the targeted vascular module of National Surgical Quality Improvement Program (NSQIP; 2011-2014). The 30-day outcomes were compared across preoperative HCT levels: severe (≤29%), moderate (29.1%-34%), mild (34.1%-39%), or no anemia (>39%), with no anemia serving as the reference group for all analyses. Independent associations between levels of anemia and postoperative outcomes were established using multivariable logistic regression. A sensitivity analysis was performed to assess interactions between preoperative anemia and blood transfusions. RESULTS: We identified 5081 patients undergoing bypass, of which 741 (15%) had severe, 1317 (26%) moderate, 1516 (30%) mild, and 1507 (30%) no anemia. Anemic patients were older and more commonly suffered from tissue loss and comorbidities (eg, hypertension, diabetes, and renal insufficiency; all P < .001). After adjustment for baseline conditions, mortality was higher in those with severe anemia (3.1%; odds ratio [OR], 2.8; 95% confidence interval [CI], 1.3-6.3) and moderate anemia (3.0%; OR, 2.6; 95% CI, 1.2-5.5) compared with those without anemia (0.7%). Severe anemia was independently associated with major amputation (6.9% vs 3.3%; OR, 1.6; 95% CI, 1.01-2.6) compared with no anemia. Anemia on admission was additionally associated with several other adverse outcomes, such as major adverse cardiovascular event (MACE; severe: OR, 1.9; 95% CI, 1.1-3.0; moderate: OR, 1.9; 95% CI, 1.3-2.9; mild: OR, 1.6; 95% CI, 1.1-2.4) and unplanned return to the operating room (severe: OR, 1.6; 95% CI, 1.2-2.1; moderate: OR, 1.5; 95% CI, 1.2-1.8; mild, OR: 1.3; 95% CI, 1.03-1.6). Moreover, mortality associated with preoperative anemia was not different in patients receiving postoperative blood transfusions compared with those who did not, whereas MACE was significantly higher in patients with preoperative anemia and blood transfusions (interaction; P < .001). CONCLUSIONS: Mortality and major adverse events in CLTI patients undergoing infrainguinal bypass are inversely associated with preoperative HCT levels, with the highest event rates in the most severely anemic patients. The correlation between anemia and MACE-but not mortality-was stronger in those patients receiving postoperative blood transfusions. Further research is needed to define an appropriate transfusion threshold, and attention should be focused on how to best optimize anemic CLTI patients before intervention.

The impact of contralateral carotid artery stenosis on outcomes after carotid endarterectomy.

OBJECTIVE: Patients with contralateral carotid occlusion (CCO) have been excluded from randomized clinical trials because of a deemed high risk for adverse neurologic outcomes with carotid endarterectomy (CEA). Evidence for this rationale is limited and conflicting. Therefore, we aimed to compare outcomes after CEA between patients with and without CCO and varying degrees of contralateral carotid stenosis (CCS). METHODS: We identified patients undergoing CEA from 2003 to 2015 in the Vascular Study Group of New England (VSGNE) registry. Patients were stratified by preoperative symptom status and presence of CCO. Multivariable analysis was used to account for differences in demographics and comorbidities. Our primary outcome was 30-day stroke/death risk. RESULTS: Of 15,487 patients we identified who underwent CEA, 10,377 (67%) were asymptomatic. CCO was present in 914 patients, of whom 681 (75%) were asymptomatic. Overall, the 30-day stroke/death was 2.0% for symptomatic patients (CCO: 2.6%) and 1.1% for asymptomatic patients (CCO: 2.3%). After adjustment, including symptom status, CCO was associated with higher 30-day stroke/death (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.4-3.3; P = .001), any in-hospital stroke (OR, 2.8; 95% CI, 1.7-4.6; P < .001), in-hospital ipsilateral stroke (OR, 2.2; 95% CI, 1.2-4.0; P = .02), in-hospital contralateral stroke (OR, 5.1; 95% CI, 2.2-11.4; P < .001), and prolonged length of stay (OR, 1.6; 95% CI, 1.3-1.9; P < .001). CCS of 80% to 99% was only associated with a prolonged length of stay (OR, 1.3; 95% CI, 1.1-1.6; P = .01), not with in-hospital stroke. Neither CCO nor CCS was associated with 30-day mortality. CONCLUSIONS: Although CCO increases the risk of 30-day stroke/death, in-hospital strokes, and prolonged length of stay after CEA, the 30-day stroke/death rates in symptomatic and asymptomatic patients with CCO remain within the recommended thresholds set by the 14 societies' guideline document. Thus, CCO should not qualify as a high-risk criterion for CEA. Moreover, there is no evidence that patients with CCO have lower stroke/death rates after carotid artery stenting than after CEA. We believe that CEA remains a valid and safe option for patients with CCO and that CCO should not be applied as a criterion to promote carotid artery stenting per se.

Perioperative outcomes of infrainguinal bypass surgery in patients with and without prior revascularization.

OBJECTIVE: Although an increasing number of patients with peripheral arterial disease undergo multiple revascularization procedures, the effect of prior interventions on outcomes remains unclear. The purpose of this study was to evaluate perioperative outcomes of bypass surgery in patients with and those without prior ipsilateral treatment. METHODS: Patients undergoing nonemergent infrainguinal bypass between 2011 and 2014 were identified in the National Surgical Quality Improvement Program Targeted Vascular module. After stratification by symptom status (chronic limb-threatening ischemia [CLTI] and claudication), patients undergoing primary bypass were compared with those undergoing secondary bypass. Within the secondary bypass group, further analysis compared prior bypass with prior endovascular intervention. Multivariable logistic regression analysis was used to establish the independent association between prior ipsilateral procedure and perioperative outcomes. RESULTS: A total of 7302 patients were identified, of which 4540 (62%) underwent primary bypass (68% for CLTI), 1536 (21%) underwent secondary bypass after a previous bypass (75% for CLTI), and 1226 (17%) underwent secondary bypass after a previous endovascular intervention (72% for CLTI). Prior revascularization on the same ipsilateral arteries was associated with increased 30-day major adverse limb event in patients with CLTI (9.8% vs 7.4%; odds ratio [OR], 1.4 [95% confidence interval (CI), 1.1-1.7]) and claudication (5.2% vs 2.5%; OR, 2.1 [95% CI, 1.3-3.5]). Similarly, secondary bypass was an independent risk factor for 30-day major reintervention (CLTI: OR, 1.4 [95% CI, 1.1-1.8]; claudication: OR, 2.1 [95% CI, 1.3-3.5]), bleeding (CLTI: OR, 1.4 [95% CI, 1.2-1.6]; claudication: OR, 1.7 [95% CI, 1.3-2.4]), and unplanned reoperation (CLTI: OR, 1.2 [95% CI, 1.0-1.4]; claudication: OR, 1.6 [95% CI, 1.1-2.1]), whereas major amputation was increased in CLTI patients only (OR, 1.3 [95% CI, 1.01-1.8]). Postoperative mortality was not significantly different in patients undergoing secondary compared with primary bypass (CLTI: 1.7% vs 2.2% [P = .22]; claudication: 0.4% vs 0.6% [P = .76]). Among secondary bypass patients with CLTI, those with prior bypass had higher 30-day reintervention rates (7.8% vs 4.9%; OR, 1.5 [95% CI, 1.0-2.2]) but fewer wound infections (7.3% vs 12%; OR, 0.6 [95% CI, 0.4-0.8]) compared with patients with prior endovascular intervention. CONCLUSIONS: Prior revascularization, in both patients with CLTI and patients with claudication, is associated with worse perioperative outcomes compared with primary bypass. Furthermore, prior endovascular intervention is associated with increased wound infections, whereas those with prior bypass had higher reintervention rates. The increasing prevalence of patients undergoing multiple interventions stresses the importance of the selection of patients for initial treatment and should be factored into subsequent revascularization options in an effort to decrease adverse events.

Risk factors for 30-day unplanned readmission following infrainguinal endovascular interventions.

OBJECTIVE: Unplanned hospital readmissions following surgical interventions are associated with adverse events and contribute to increasing health care costs. Despite numerous studies defining risk factors following lower extremity bypass surgery, evidence regarding readmission after endovascular interventions is limited. This study aimed to identify predictors of 30-day unplanned readmission following infrainguinal endovascular interventions. METHODS: We identified all patients undergoing an infrainguinal endovascular intervention in the targeted vascular module of the American College of Surgeons National Surgical Quality Improvement Program between 2012 and 2014. Perioperative outcomes were stratified by symptom status (chronic limb-threatening ischemia [CLI] vs claudication). Patients who died during index admission and those who remained in the hospital after 30 days were excluded. Indications for unplanned readmission related to the index procedure were evaluated. Multivariable logistic regression was used to identify preoperative and in-hospital (during index admission) risk factors of 30-day unplanned readmission. RESULTS: There were 4449 patients who underwent infrainguinal endovascular intervention, of whom 2802 (63%) had CLI (66% tissue loss) and 1647 (37%) had claudication. The unplanned readmission rates for CLI and claudication patients were 16% (n = 447) and 6.5% (n = 107), respectively. Mortality after index admission was higher for readmitted patients compared with those not readmitted (CLI, 3.4% vs 0.7% [P < .001]; claudication, 2.8% vs 0.1% [P < .01]). Approximately 50% of all unplanned readmissions were related to the index procedure. Among CLI patients, the most common indication for readmission related to the index procedure was wound or infection related (42%), whereas patients with claudication were mainly readmitted for recurrent symptoms of peripheral vascular disease (28%). In patients with CLI, predictors of unplanned readmission included diabetes (odds ratio, 1.3; 95% confidence interval, 1.01-1.6), congestive heart failure (1.6; 1.1-2.5), renal insufficiency (1.7; 1.3-2.2), preoperative dialysis (1.4; 1.02-1.9), tibial angioplasty/stenting (1.3; 1.04-1.6), in-hospital bleeding (1.9; 1.04-3.5), in-hospital unplanned return to the operating room (1.9; 1.1-3.5), and discharge other than to home (1.5; 1.1-2.0). Risk factors for those with claudication were dependent functional status (3.5; 1.4-8.7), smoking (1.6; 1.02-2.5), diabetes (1.5; 1.01-2.3), preoperative dialysis (3.6; 1.6-8.3), procedure time exceeding 120 minutes (1.8; 1.1-2.7), in-hospital bleeding (2.9; 1.2-7.4), and in-hospital unplanned return to the operating room (3.4; 1.2-9.4). CONCLUSIONS: Unplanned readmission after endovascular treatment is relatively common, especially in patients with CLI, and is associated with substantially increased mortality. Awareness of these risk factors will help providers identify patients at high risk who may benefit from early surveillance, and prophylactic measures focused on decreasing postoperative complications may reduce the rate of readmission.

Sex differences in mortality and morbidity following repair of intact abdominal aortic aneurysms.

OBJECTIVE: Medicare studies have shown increased perioperative mortality in women compared with men following endovascular and open abdominal aortic aneurysm (AAA) repair. However, a recent regional study of high-volume centers, adjusting for anatomy but limited in sample size, did not show sex to be predictive of worse outcomes. This study aimed to evaluate sex differences after intact AAA repair in a national clinical registry. METHODS: The targeted vascular module of the National Surgical Quality Improvement Program was queried to identify patients undergoing endovascular aneurysm repair (EVAR) or open repair for intact, infrarenal AAA from 2011 to 2014. Univariate analysis was performed using the Fisher exact test and Mann-Whitney test. Multivariable logistic regression was used to account for differences in comorbidities, aneurysm details, and operative characteristics. RESULTS: We identified 6611 patients (19% women) who underwent intact AAA repair (87% EVAR; 83% women vs 88% men; P < .001). Women were older (median age, 76 vs 73 years; P < .001), had smaller aneurysms (median, 5.4 vs 5.5 cm; P < .001), and had more chronic obstructive pulmonary disease (22% vs 17%; P < .001). Among patients undergoing EVAR, women had longer operative times (median, 138 [interquartile range, 103-170] vs 131 [106-181] minutes; P < .01) and more often underwent renal (6.3% vs 4.1%; P < .01) and lower extremity (6.6% vs 3.8%; P < .01) revascularization. After open repair, women had shorter operative time (215 [177-304] vs 226 [165-264] minutes; P = .02), but women less frequently underwent lower extremity revascularization (3.1% vs 8.2%; P = .03). Thirty-day mortality was higher in women after EVAR (3.2% vs 1.2%; P < .001) and open repair (8.0% vs 4.0%; P = .04). After adjusting for repair type, age, aneurysm diameter, and comorbidities, female sex was independently associated with mortality (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.1-2.6; P = .02) and major complications (OR, 1.4; CI, 1.1-1.7; P < .01) after intact AAA repair. However, after adjusting for aortic size index rather than for aortic diameter, the association between female sex and mortality (OR, 1.5; CI, 0.98-2.4; P = .06) and major complications (OR, 1.1; CI, 0.9-1.4; P = .24) was reduced. CONCLUSIONS: Women were at higher risk for 30-day death and major complications after intact AAA repair. Some of this disparity may be explained by differences in aortic size index, which should be further evaluated to determine the ideal threshold for repair.

Intraluminal delivery of thrombospondin-2 small interfering RNA inhibits the vascular response to injury in a rat carotid balloon angioplasty model.

In an effort to inhibit the response to vascular injury that leads to intimal hyperplasia, this study investigated the in vivo efficacy of intraluminal delivery of thrombospondin-2 (TSP-2) small interfering RNA (siRNA). Common carotid artery (CCA) balloon angioplasty injury was performed in rats. Immediately after denudation, CCA was transfected intraluminally (15 min) with one of the following: polyethylenimine (PEI)+TSP-2 siRNA, saline, PEI only, or PEI+control siRNA. CCA was analyzed at 24 h or 21 d by using quantitative real-time PCR and immunohistochemistry. TSP-2 gene and protein expression were significantly up-regulated after endothelial denudation at 24 h and 21 d compared with contralateral untreated, nondenuded CCA. Treatment with PEI+TSP-2 siRNA significantly suppressed TSP-2 gene expression (3.1-fold) at 24 h and TSP-2 protein expression, cell proliferation, and collagen deposition up to 21 d. These changes could be attributed to changes in TGF-ß and matrix metalloproteinase-9, the downstream effectors of TSP-2. TSP-2 knockdown induced anti-inflammatory M2 macrophage polarization at 21 d; however, it did not significantly affect intima/media ratios. In summary, these data demonstrate effective siRNA transfection of the injured arterial wall and provide a clinically effective and translationally applicable therapeutic strategy that involves nonviral siRNA delivery to ameliorate the response to vascular injury.-Bodewes, T. C. F., Johnson, J. M., Auster, M., Huynh, C., Muralidharan, S., Contreras, M., LoGerfo, F. W., Pradhan-Nabzdyk, L. Intraluminal delivery of thrombospondin-2 small interfering RNA inhibits the vascular response to injury in a rat carotid balloon angioplasty model.