Thomas C.F. Bodewes

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 6661 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.

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.

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.

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.

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.