Use of Intravascular Ultrasound During First-Time Femoropopliteal Peripheral Vascular Interventions Among Medicare Beneficiaries.

BACKGROUND: Intravascular ultrasound (IVUS) may be a useful adjunct to lower extremity peripheral vascular interventions (PVI) in certain clinical scenarios. We aimed to identify patient- and physician-level characteristics associated with the use of IVUS during first-time femoropopliteal PVI. METHODS: We included all Medicare beneficiaries undergoing elective femoropopliteal PVI for claudication or chronic limb-threatening ischemia between 01/01/2019 and 12/31/2019. We excluded patients with prior open or endovascular femoropopliteal intervention and all physicians performing ≤10 PVI during the study period. We calculated the proportion of patients who had IVUS performed as part of their index PVI for each physician. Hierarchical logistic regression was used to evaluate patient- and physician-level factors associated with use of IVUS. RESULTS: We identified 58,552 patients who underwent index femoropopliteal PVI, of whom 11,394 (19%) received IVUS. A total of 1,628 physicians performed >10 procedures during the study period, with IVUS utilization ranging from 0-100%. After hierarchical regression, claudication (versus chronic limb-threatening ischemia: OR 1.23, 95% CI 1.11-1.36), stenting (versus angioplasty alone: OR 1.57, 1.33-1.86) and atherectomy (versus angioplasty alone: OR 2.09, 1.83-2.39) were associated with higher odds of IVUS utilization. Higher-volume providers (tertile 3 vs. tertile 1: OR 3.78, 2.43-5.90) and those with high rates of service provided in an office-based laboratory (tertile 3 vs. tertile 1: OR 10.72, 6.78-19.93) were more likely to utilize IVUS. Radiologists (OR 11.23, 5.96-21.17) and cardiologists (OR 1.97, 1.32-2.93) used IVUS more frequently than vascular surgeons. CONCLUSIONS: Wide variability exists in the use of IVUS for first-time femoropopliteal PVI. The association of IVUS with claudication, atherectomy, and office-based laboratories raises concern about its potential overuse by some physicians.

Index and follow-up costs of endovascular abdominal aortic aneurysm repair from the Endurant Stent Graft System Post Approval Study (ENGAGE PAS).

OBJECTIVE: Trials for endovascular aneurysm repair (EVAR) report lower perioperative mortality and morbidity, but also higher costs compared with open repair. However, few studies have examined the subsequent cost of follow-up evaluations and interventions. Therefore, we present the index and 5-year follow-up costs of EVAR from the Endurant Stent Graft System Post Approval Study. METHODS: From August 2011 to June 2012, 178 patients were enrolled in the Endurant Stent Graft System Post Approval Study de novo cohort and treated with the Medtronic Endurant stent graft system (Medtronic Vascular, Santa Rosa, Calif), of whom 171 (96%) consented for inclusion in the economic analysis and 177 participated in the quality-of-life (QOL) assessment over a 5-year follow-up period. Cost data for the index and follow-up hospitalizations were tabulated directly from hospital bills and categorized by Uniform Billing codes. Surgeon costs were calculated by Current Procedural Terminology codes for each intervention. Current Procedural Terminology codes were also used to calculate imaging and clinic follow-up reimbursement as surrogate to cost based on year-specific Medicare payment rates. Additionally, we compared aneurysm-related versus nonaneurysm-related subsequent hospitalization costs and report EuroQol 5D QOL dimensions. RESULTS: The mean hospital cost per person for the index EVAR was $45,304 (interquartile range [IQR], $25,932-$44,784). The largest contributor to the overall cost was operating room supplies, which accounted for 50% of the total cost at a mean of $22,849 per person. One hundred patients had 233 additional post index admission inpatient admissions; however, only 32 readmissions (14%) were aneurysm related, with a median cost of $13,119 (IQR, $4570-$24,153) compared with a nonaneurysm-related median cost of $6609 (IQR, $1244-$26,466). Additionally, 32 patients were admitted a total of 37 times for additional procedures after index admission, of which 14 (38%) were aneurysm-related. The median cost of hospitalization for aneurysm-related subsequent intervention was $22,023 (IQR, $13,177-$47,752), compared with a median nonaneurysm-related subsequent intervention cost of $19,007 (IQR, $8708-$33,301). After the initial 30-day visit, outpatient follow-up imaging reimbursement averaged $550 per person per year ($475 for computed tomography scans, $75 for the abdomen), whereas annual office visits averaged $107 per person per year, for a total follow-up reimbursement of $657 per person per year. There were no significant differences in the five EuroQol 5D QOL dimensions at each follow-up compared with baseline. CONCLUSIONS: Costs associated with index EVAR are driven primarily by cost of operating room supplies, including graft components. Subsequent admissions are largely not aneurysm related; however, cost of aneurysm-related hospitalizations is higher than for nonaneurysm admissions. These data will serve as a baseline for comparison with open repair and other devices.

Transabdominal open abdominal aortic aneurysm repair is associated with higher rates of late reintervention and readmission compared with the retroperitoneal approach.

OBJECTIVE: Limited data exist comparing the transabdominal and retroperitoneal approaches to open abdominal aortic aneurysm (AAA) repair, especially late mortality and laparotomy-related reinterventions and readmissions. Therefore, we compared long-term rates of mortality, reintervention, and readmission after open AAA repair through a transabdominal compared with a retroperitoneal approach. METHODS: We identified all patients in the Vascular Quality Initiative (VQI) undergoing open AAA repair from 2003 to 2015. Patients with rupture or supraceliac clamp were excluded. We used the VQI linkage to Medicare to ascertain rates of long-term outcomes, including rates of AAA-related and laparotomy-related (ie, hernia, bowel obstruction) reinterventions and readmissions. We used multivariable Cox regression to account for differences in comorbidities, aneurysm details, and operative characteristics. RESULTS: We identified 1282 patients in the VQI with linkage to Medicare data, 914 (71%) who underwent a transperitoneal approach and 368 (29%) who underwent a retroperitoneal approach. Patients who underwent a retroperitoneal approach were slightly more likely to have preoperative renal insufficiency but were otherwise similar in terms of demographics and comorbidities. They more often had a clamp above at least one renal artery (61% vs 36%; P < .001) and underwent concomitant renal revascularization (9.5% vs 4.3%; P < .001). Patients who underwent a transabdominal approach more often presented with symptoms (14% vs 9.0%; P < .01) and had a femoral distal anastomosis (15% vs 7.1%; P < .001). There was no difference in 5-year survival (62% vs 61%; log-rank, P = .51). However, patients who underwent a transabdominal approach experienced higher rates of repair-related reinterventions and readmissions (5-year: 42% vs 34%; log-rank, P < .01), even after adjustment for demographic and operative differences (hazard ratio, 1.5; 95% confidence interval, 1.1-1.9; P < .01). CONCLUSIONS: A transabdominal exposure for AAA repair is associated with higher rates of late reintervention and readmission than with the retroperitoneal approach, which should be considered when possible in operative decision-making.

Regional variation in racial disparities among patients with peripheral artery disease.

OBJECTIVE: Prior studies identified significant racial disparities as well as regional variation in outcomes of patients with peripheral artery disease (PAD). We aimed to determine whether regional variation contributes to these racial disparities. METHODS: We identified all white or black patients who underwent infrainguinal revascularization or amputation in 15 deidentified regions of the Vascular Quality Initiative between 2003 and 2017. We excluded three regions with <100 procedures. We used multivariable linear regression, allowing clustering at the hospital level to calculate the marginal effects of race and region on adjusted 30-day mortality, major adverse limb events (MALEs), and amputation. We compared long-term outcomes between black and white patients within each region and within patients of each race treated in different regions using multivariable Cox regression. RESULTS: We identified 90,418 patients, 15,527 (17%) of whom were black. Patients underwent 31,263 bypasses, 52,462 endovascular interventions, and 6693 amputations. Black patients were younger and less likely to smoke, to have coronary artery disease, or to have chronic obstructive pulmonary disease, but they were more likely to have diabetes, limb-threatening ischemia, dialysis dependence, and hypertension and to be self-insured or on Medicaid (all P < .05). Adjusted 30-day mortality ranged from 1.2% to 2.1% across regions for white patients and 0% to 3.0% for black patients; adjusted 30-day MALE varied from 4.0% to 8.3% for white patients and 2.4% to 8.1% for black patients; and adjusted 30-day amputation rates varied from 0.3% to 1.2% for white patients and 0% to 2.1% for black patients. Black patients experienced significantly different (both higher and lower) adjusted rates of 30-day mortality and amputation than white patients did in several regions (P < .05) but not MALEs. In addition, within each racial group, we found significant variation in the adjusted rates of all outcomes between regions (all P < .01). In adjusted analyses, compared with white patients, black patients experienced consistently lower long-term mortality (hazard ratio [HR], 0.80; 95% confidence interval [CI], 0.73-0.88; P < .001) and higher rates of MALEs (HR, 1.15; 95% CI, 1.06-1.25; P < .001) and amputation (HR, 1.33; 95% CI, 1.18-1.51; P < .001), with no statistically significant variation across the regions. However, rates of all long-term outcomes varied within both racial groups across regions. CONCLUSIONS: Significant racial disparities exist in outcomes after lower extremity procedures in patients with PAD, with regional variation contributing to perioperative but not long-term outcome disparities. Underperforming regions should use these data to generate quality improvement projects, as understanding the etiology of these disparities is critical to improving the care of all patients with PAD.

The impact of race on outcomes after carotid endarterectomy in the United States.

OBJECTIVE: Black patients undergoing carotid endarterectomy (CEA) in the United States are more often symptomatic at presentation and have more comorbidities compared with white patients. However, the impact of race on outcomes after CEA is largely unknown. METHODS: We identified CEA patients in the Vascular Quality Initiative registry (2012-2017) and compared them by race (black vs white). All other nonwhite races (891 [1.4%]) and Hispanics (2222 [3.4%]) were excluded. We used multilevel logistic regression to account for differences in demographics and comorbidities. We assessed long-term survival using multivariable Cox regression. The primary outcome was perioperative stroke/death, with long-term survival as a secondary outcome. RESULTS: We included 57,622 CEA patients; 2909 (5.0%) were black, of whom 983 (34%) were symptomatic. Of the 54,713 white patients, 16,132 (30%) were symptomatic. Black patients, compared with white patients, had a higher vascular disease burden and were less likely to be operated on in a high-volume hospital or by a high-volume surgeon. In addition, black symptomatic patients, compared with white symptomatic patients, were more often operated on <2 weeks after the index neurologic symptom (47% vs 40%; P < .001). Perioperative stroke/death was comparable between black and white patients (symptomatic, 2.8% vs 2.2% [P = .2]; asymptomatic, 1.6% vs 1.3% [P = .2]), as was unadjusted survival at 3 years (93% vs 93%; P = .7). However, after adjustment, black patients did experience better long-term survival compared with white patients (hazard ratio, 0.8; 95% confidence interval, 0.7-0.9; P = .01). On multilevel logistic regression, race was not associated with perioperative stroke/death (odds ratio, 1.0; 95% confidence interval, 0.8-1.3; P = .98). CONCLUSIONS: Despite the greater prevalence of vascular risk factors in black patients and racial inequalities in surgical treatment, rates of perioperative stroke/death and unadjusted survival were similar between white and black patients. Moreover, black patients experienced better adjusted long-term survival after CEA.

Black patients present with more severe vascular disease and a greater burden of risk factors than white patients at time of major vascular intervention.

BACKGROUND: Although many studies have demonstrated racial disparities after major vascular surgery, few have identified the reasons for these disparities, and those that did often lacked clinical granularity. Therefore, our aim was to evaluate differences in initial vascular intervention between black and white patients. METHODS: We identified black and white patients' initial carotid, abdominal aortic aneurysm (AAA), and infrainguinal peripheral artery disease (PAD) interventions in the Vascular Quality Initiative (VQI) registry from 2009 to 2014. We excluded nonblack or nonwhite patients as well as those with Hispanic ethnicity, asymptomatic PAD, or a history of prior ipsilateral interventions. We compared baseline characteristics and disease severity at time of intervention on a national and regional level. RESULTS: We identified 76,372 patients (9% black), including 35,265 carotid (5% black), 17,346 AAA (5% black), and 23,761 PAD interventions (18% black). For all operations, black patients were younger, more likely female, and had more insulin-dependent diabetes, hypertension, congestive heart failure, renal dysfunction, and dialysis dependence. Black patients were less likely to be on a statin before AAA (62% vs 69%; P < .001) or PAD intervention (61% vs 67%; P < .001) and also less likely to be discharged on an antiplatelet and statin regimen after these procedures (AAA, 60% vs 64% [P = .01]; PAD, 64% vs 67% [P < .001]). Black patients presented with more severe disease, including higher proportions of symptomatic carotid disease (36% vs 31%; P < .001), symptomatic or ruptured AAA (27% vs 16%; P < .001), and chronic limb-threatening ischemia (73% vs 62%; P < .001). Black patients more often presented with concurrent iliac artery aneurysms at the time of AAA repair (elective open AAA repair, 46% vs 26% [P < .001]; elective endovascular aneurysm repair, 38% vs 23% [P < .001]). CONCLUSIONS: Black patients present with more advanced disease at the time of initial major vascular operation. Efforts to control risk factors, identify and treat arterial disease in a timely fashion, and optimize medical management among black patients may provide opportunity to improve current disparities.

Comparison of Endovascular Stent Grafts for Abdominal Aortic Aneurysm Repair in Medicare Beneficiaries.

BACKGROUND: Increased renal complications have been suggested with suprarenal stent grafts, but long-term analyses have been limited. Therefore, the purpose of this study was to evaluate the effect of endograft choice on perioperative and long-term outcomes. METHODS: We compared Medicare beneficiaries undergoing endovascular abdominal aortic aneurysms repair from 2005 to 2008 with endografts with infrarenal fixation and a single docking limb (AneuRx, Excluder) to those with suprarenal fixation and 2 docking limbs (Zenith), or a unibody configuration (Powerlink). Propensity score weighting accounted for differences in patient characteristics among the different graft formations, and perioperative mortality, complications, and length of stay and 4-year rates of survival, rupture, and reintervention were compared. RESULTS: Forty-six thousand one hundred seventy-one Medicare beneficiaries were identified including 11,002 (24%) with suprarenal fixation, 32,909 (71%) with infrarenal fixation, and 2,260 (5%) with a unibody graft. After propensity score weighting, there were no significant differences in patients' baseline clinical and demographic characteristics. The suprarenal fixation patients had higher rates of perioperative mortality (1.7% vs. 1.3%, P < 0.01), renal failure (6.0% vs. 4.7%, P < 0.001), and mesenteric ischemia (0.7% vs. 0.4%, P < 0.01) and longer length of stay (3.4 days vs. 3.0 days, P < 0.001) compared with patients with infrarenal fixation. Unibody grafts had higher rates of renal failure (5.9% vs. 4.7%, P < 0.001), mesenteric ischemia (1.0% vs. 0.4%, P < 0.001), and conversion to open repair (0.7% vs. 0.1%, P < 0.001) compared to those with infrarenal fixation and single docking limbs. At 4 years, mortality remained slightly higher with suprarenal compared to infrarenal fixation (30% vs. 29%, P = 0.047), although these patients had fewer conversions to open repair (0.6% vs. 0.9%, P = 0.03) and aneurysm-related reinterventions (10% vs. 12%, P < 0.01). At 4 years, unibody grafts had more aneurysm-related interventions compared to infrarenal fixation grafts (15% vs. 12%, P < 0.01) but fewer conversions to open repair (0.4% vs. 0.9%, P = 0.02). Late rupture did not differ among the groups. CONCLUSIONS: Compared to infrarenal fixation devices, patients who underwent EVAR with suprarenal fixation had higher perioperative mortality and renal complications but fewer reinterventions including conversion, while the unibody graft had more perioperative complications and aneurysm-related reinterventions, but fewer conversions to open repair. Although these differences could be explained by selection bias, these data suggest that further comparative effectiveness analyses should be performed to understand the outcomes following EVAR with suprarenal fixation and unibody grafts.

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.

Select early type IA endoleaks after endovascular aneurysm repair will resolve without secondary intervention.

OBJECTIVE: Although it is traditionally considered ominous, the natural history of early proximal attachment site endoleaks (IA) after endovascular aneurysm repair (EVAR) is not well known. Our aim was to identify risk factors for persistent type IA endoleaks and to determine their effect on long-term outcomes after EVAR. METHODS: All patients who underwent infrarenal EVAR at a single institution between 1998 and 2015 were identified. Preoperative axial imaging and intraoperative arteriograms were reviewed, and those patients with a type IA endoleak were further studied. Aneurysm features were characterized by two reviewers and were studied for predictors of persistent endoleaks at the conclusion of the case. Patient records and the Social Security Death Index were used to record 1-year and overall survival. RESULTS: We identified 1484 EVARs, 122 (8%) of which were complicated by a type IA endoleak on arteriography after graft deployment, with a median follow-up of 4 years. The majority of patients underwent additional ballooning of the proximal site (52 [43%]) or placement of an aortic cuff (47 [39%]); 30 patients (25%) received a Palmaz stent, and four patients were treated with coils or anchors. At case end, only 43 (35%) of the type IA endoleaks remained; at 1 month, only 16 endoleaks persisted (13%), and only six persisted at 1 year (6%). In multivariable analysis, the only independent predictor of persistence of type IA endoleak at the conclusion of the case was the presence of extensive neck calcifications (odds ratio [OR], 9.9; 95% confidence interval [CI], 1.4-67.9; P = .02). Thirteen patients (11%) underwent reintervention for type IA endoleaks, with a time frame ranging from 3 days postoperatively to 11 years. There were three patients (2.4%) who experienced aneurysm rupture. Postoperative type IA endoleak was associated with lower survival at 1 year (79% vs 91%; relative risk, 2.5; 95% CI, 1.1-5.4; P = .02), but it did not affect long-term survival (log-rank, P = .45). Both an increase in aneurysm sac size and failure of the endoleak to resolve by case end were independent predictors of a need for reintervention (growth: OR, 8.3; 95% CI, 2.2-31.6; P < .01; persistent endoleak: OR, 7.6; 95% CI, 1.8-31.5; P < .01). A persistent type IA endoleak was not independently associated with an increase in sac size on surveillance imaging (P = .28). CONCLUSIONS: Aneurysm rupture secondary to persistent type IA endoleak is rare, and most will resolve within 1 year. Extensive neck calcification is the only independent predictor of persistent type IA endoleak, and an increase in sac size warrants reintervention. These data suggest that select early persistent type IA endoleaks can be safely observed.

Racial disparities in outcomes after intact abdominal aortic aneurysm repair.

OBJECTIVE: We aimed to compare perioperative morbidity and mortality and late survival among black, white, and Asian patients undergoing intact abdominal aortic aneurysm (AAA) repair. METHODS: We identified all patients undergoing intact, infrarenal AAA repair in the Vascular Quality Initiative (VQI) from 2003 to 2017. We compared in-hospital outcomes by race using the Fisher exact and Kruskal-Wallis tests. Multivariable logistic and linear regression models of perioperative outcomes adjusted for differences in demographics, comorbidities, hospital volume, and procedure. We used Cox regression to evaluate late survival by race. RESULTS: In the cohort, 21,961 (94%) patients were white, 1215 (5.2%) were black, and 318 (1.4%) were Asian. Black patients were more likely to be symptomatic (black, 16%; white, 9.1%; Asian, 11%; P < .001) and to undergo endovascular aneurysm repair (EVAR; black, 87%; white, 83%; Asian, 84%; P < .001). There were no differences in 30-day mortality after EVAR (black, 1.1%; white, 1.1%; Asian, 0.8%; P = .80) or open repair (black; 4.3%; white, 2.6%; Asian, 1.9%; P = .33). However, black patients were more likely to receive new postoperative dialysis (black, 1.6%; white, 0.8%; Asian; 0.7%; P = .01) and to return to the operating room (black, 4.3%; white, 2.9%; Asian, 0.9%; P < .01). Mean hospital length of stay was longer in black patients after EVAR (black, 3.3 days; white, 2.6 days; Asian, 2.6 days; P < .001) and in Asian and black patients after open repair (black, 10.5 days; white, 8.5 days; Asian, 13.0 days; P < .001). After multivariable adjustment, black patients were more likely than white patients to have postoperative dialysis (odds ratio, 2.2; 95% confidence interval [CI], 1.3-3.6; P < .01) and return to the operating room (odds ratio, 1.6; 95% CI, 1.2-2.2; P < .01). Five-year survival was highest for Asian patients (black, 84%; white, 85%; Asian, 92%), even in the adjusted Cox model (Asian: hazard ratio, 0.6; 95% CI, 0.4-0.97; P = .04). CONCLUSIONS: Although perioperative mortality is comparable across races after AAA repair, black patients are more likely than white or Asian patients to develop new postoperative renal failure and return to the operating room, even after adjusting for differences in comorbidities, operative variables, and hospital volume. In addition, whereas Asian patients have the highest rate of postoperative myocardial infarction, they also have the highest late survival. Further studies are warranted to elucidate the mechanism of these disparities.

Open versus endovascular abdominal aortic aneurysm repair in Medicare beneficiaries.

Abdominal aortic aneurysms are relatively common and often life-threatening, with especially high mortality after aneurysm rupture. The introduction of endovascular aneurysm repair, a minimally invasive alternative to traditional open repair, led to decreased mortality and morbidity in randomized controlled trials, but these trials were conducted in highly selected patients and providers and were underpowered to detect differences in rare adverse events throughout follow-up. With observational studies of Medicare beneficiaries, we demonstrate that the randomized trial results are generalizable to the majority of patients undergoing abdominal aortic aneurysm repair in the United States. Additionally, with a larger cohort, comparative analyses evaluating rare, previously unstudied late outcomes such as laparotomy-related complications, late reinterventions, mortality with reinterventions, and late rupture could be conducted. Furthermore, trends in management over time and relationships between surgeon and hospital volume and outcomes can be studied. The goal of this review was to summarize the existing literature regarding abdominal aortic aneurysms among Medicare beneficiaries and to evaluate the benefits and limitations of administrative claims data in comparative effectiveness research.

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.

The effect of surgeon and hospital volume on mortality after open and endovascular repair of abdominal aortic aneurysms.

BACKGROUND: Higher hospital and surgeon volumes are independently associated with improved mortality after open repair of abdominal aortic aneurysms (AAAs) in the era before endovascular AAA repair (EVAR). The effects of both surgeon and hospital volume on mortality after EVAR and open repair in the current era are less well defined. METHODS: We studied Medicare beneficiaries who underwent elective AAA repair from 2001 to 2008. Volume was measured by procedure type during the 1-year period preceding each procedure and was further categorized into quintiles of volume for surgeon and hospital. Multilevel logistic regression models were used to evaluate the effect of surgeon volume, accounting for hospital volume, on mortality after adjusting for patient demographic and comorbid conditions as well as the analogous effect of hospital volume adjusting for surgeon volume. The multilevel models included random effects for surgeon and hospital to account for the clustering of multiple patients within the same surgeon and within the same hospital. RESULTS: We studied 122,495 patients who underwent AAA repair (open: 45,451; EVAR: 77,044). After EVAR, perioperative mortality did not differ by surgeon volume (quintile 1 [0-6 EVARs]: 1.8%; quintile 5 [28-151 EVARs]: 1.6%; P = .29), but decreased with greater hospital volume (quintile 1 [0-9 EVARs]: 1.9%; quintile 5 [49-198 EVARs]: 1.4%; P < .01). After open repair, perioperative mortality decreased with both higher surgeon volume (quintile 1 [0-3 open repairs]: 6.4%; quintile 5 [14-62 open repairs]: 3.8%; P < .01) and hospital volume (quintile 1 [0-5 open repairs]: 6.3%; quintile 5 [14-62 open repairs]: 3.8%; P < .01). After adjustment for other predictors, surgeon volume was not associated with perioperative mortality after EVAR (odds ratio [OR], 0.9; 95% confidence interval [CI], 0.7-1.1); however, hospital volume was associated with higher perioperative mortality (quintile 1: OR, 1.5; 95% CI, 1.2-1.9; quintile 2: OR, 1.3; 95% CI, 1.02-1.6; and quintile 3: OR, 1.2; 95% CI, 1.01-1.5, compared with 5). After open repair, higher surgeon volume was also associated with lower mortality (quintile 1: OR, 1.5; 95% CI, 1.3-1.8; quintile 2: OR, 1.3; 95% CI, 1.1-1.6; and quintile 3: OR, 1.2; 95% CI, 1.1-1.4, compared with 5). Risk of mortality also was higher for patients treated at lower-volume hospitals (quintile 1: OR, 1.3; 95% CI, 1.1-1.5; quintile 2: OR, 1.3; 95% CI, 1.1-1.5; and quintile 3: OR, 1.2; 95% CI, 1.1-1.4, compared with 5). CONCLUSIONS: After EVAR, hospital volume is minimally associated with perioperative mortality, with no such association for surgeon volume. After open AAA repair, surgeon and hospital volume are both strongly associated with mortality. These findings suggest that open surgery should be concentrated in hospitals and surgeons with high volume.