Risk factors and outcomes for bowel ischemia after open and endovascular abdominal aortic aneurysm repair.

Bowel ischemia (BI) is a serious complication after abdominal aortic aneurysm (AAA) repair. We sought to identify the incidence and risk factors associated with the development of postoperative BI and the post-BI outcomes for patients undergoing open aortic repair (OAR) and endovascular aortic repair (EVAR) of AAAs. A retrospective analysis was conducted for all patients who had undergone OAR or EVAR from 2003 to 2017 using the Vascular Quality Initiative database. Univariate (Student's t test, χ2, median) and multivariable (logistic regression) analyses were used to identify independent factors associated with postoperative BI and compare the post-BI in-hospital outcomes and mortality. We identified 45,474 patients who had undergone infrarenal AAA repair (OAR, 21.5%; EVAR, 78.5%). The overall incidence of postoperative BI was 1.9% (OAR, 6.2% vs EVAR, 0.8%; P < .001). OAR was associated with a threefold increased odds of BI compared with EVAR (adjusted odds ratio [aOR], 3.24; 95% confidence interval [CI], 2.49-4.22; P < .001). The independent factors associated with BI after OAR included older age (aOR per year of age, 1.02; 95% CI, 1.00-1.03), congestive heart failure (aOR, 1.44; 95% CI, 1.05-1.98), and ruptured aneurysm (aOR, 4.16; 95% CI, 2.98-5.81; P < .01 for all). We also found that transfusion ≥1 U (aOR, 1.69; 95% CI, 1.30-2.20), a transperitoneal approach (aOR, 2.13; 95% CI, 1.03-1.87), supraceliac clamping (aOR, 1.58; 95% CI, 1.08-2.33), and inferior mesenteric artery reimplantation (aOR, 1.41; 95% CI, 1.06-1.89) were associated with greater odds of BI after OAR (P < .01 for all). Similarly, we found that ruptured aneurysms, a longer operative time, and transfusion of ≥1 U of blood were associated with BI after EVAR (P < .001 for all). For both OAR and EVAR, the postoperative stay (median, 13 days [interquartile range (IQR), 7-26 days] vs 7 days [IQR, 5-10 days] and 11 days [IQR, 4-23 days] vs 1 day [IQR, 1-3 days], respectively) and 30-day mortality (35.0% vs 6.4% and 40.5% vs 1.9%, respectively) were significantly higher for patients with BI (P < .001 for all). The predictors of mortality for patients with BI were surgical management (aOR, 2.05; 95% CI, 1.28-3.30), older age (aOR, 1.05; 95% CI, 1.02-1.07), symptomatic aneurysm (aOR, 1.26; 95% CI, [0.60-2.62), ruptured aneurysm (aOR, 2.23; 95% CI, 1.43-3.48), longer operative time (aOR, 1.11; 95% CI, 1.01-1.22), and postoperative renal complications (aOR, 2.98; 95% CI, 1.80-4.96; P < .05 for all). Confirming the results from previous studies, we found that BI is more common after a ruptured aneurysm and OAR. Other associated intraoperative factors included a transperitoneal approach, supraceliac clamping, and a reimplanted inferior mesenteric artery. More than one third of patients who developed postoperative BI in our cohort had died within 30 days after AAA repair. The factors associated with mortality after BI included surgical management and postoperative renal failure. A high index of suspicion for the signs and symptoms of BI should be maintained postoperatively for patients presenting with the risk factors identified.

Gurakar M ，Locham S ，Alshaikh HN ，Malas MB ... -  《-》

Risk factors and outcomes of postoperative ischemic colitis in contemporary open and endovascular abdominal aortic aneurysm repair.

Postoperative ischemic colitis (IC) can be a serious complication following infrarenal abdominal aortic aneurysm (AAA) repair. We sought to identify risk factors and outcomes in patients developing IC after open AAA repair and endovascular aneurysm repair (EVAR). The American College of Surgeons National Surgical Quality Improvement Program database was used to examine clinical data of patients undergoing AAA repair from 2011 to 2012 who developed postoperative IC. Multivariate regression analysis was performed to identify risk factors and outcomes. We evaluated a cohort of 3486 patients who underwent AAA repair (11.6% open repair and 88.4% EVAR). The incidence of postoperative IC was 2.2% (5.2% for open repair and 1.8% for EVAR). Surgical treatment was needed in 49.3% of patients who developed IC. The mortality of patients with IC was higher than that of patients without IC (adjusted odds ratio [AOR], 4.23; 95% confidence interval [CI], 2.26-7.92; P < .01). The need for surgical treatment (AOR, 7.77; 95% CI, 2.08-28.98; P < .01) and age (AOR, 1.11; 95% CI, 1.01-1.22; P = .01) were mortality predictors of IC patients. Predictive factors of IC included need for intraoperative or postoperative transfusion (AOR, 6; 95% CI, 3.08-11.72; P < .01), rupture of the aneurysm before surgery (AOR, 4.07; 95% CI, 1.78-9.31; P < .01), renal failure requiring dialysis (AOR, 3.86; 95% CI, 1.18-12.62; P = .02), proximal extension of the aneurysm (AOR, 2.19; 95% CI, 1.04-4.59; P = .03), diabetes (AOR, 1.87; 95% CI, 1.01-3.46; P = .04), and female gender (AOR, 1.75; 95% CI, 1.01-3.02; P = .04). Although open AAA repair had three times higher rate of postoperative IC compared with endovascular repair, in multivariate analysis we did not find any statistically significant difference between open repair and EVAR in the development of IC (5.2% vs 1.8%; AOR, 1.25; 95% CI, 0.70-2.25; P = .43). Postoperative IC has a rate of 2.2% after AAA repair. However, it is associated with 38.7% mortality rate. Rupture of the aneurysm before surgery, need for transfusion, proximal extension of the aneurysm, renal failure requiring dialysis, diabetes, and female gender were significant predictors of postoperative IC. AAA patients who develop IC have four times higher mortality compared with those without IC. Surgical treatment is needed in nearly 50% of IC patients and is a predictor of higher mortality.

Moghadamyeghaneh Z ，Sgroi MD ，Chen SL ，Kabutey NK ，Stamos MJ ，Fujitani RM ... -  《-》

Incidence of and risk factors for bowel ischemia after abdominal aortic aneurysm repair.

Bowel ischemia is a rare but devastating complication after abdominal aortic aneurysm (AAA) repair. Its rarity has prohibited extensive risk-factor analysis, particularly since the widespread adoption of endovascular AAA repair (EVAR); therefore, this study assessed the incidence of postoperative bowel ischemia after AAA repair in the endovascular era and identified risk factors for its occurrence. All patients undergoing intact or ruptured AAA repair in the Vascular Study Group of New England (VSGNE) between January 2003 and November 2014 were included. Patients with and without postoperative bowel ischemia were compared and stratified by indication (intact and ruptured) and treatment approach (open repair and EVAR). Criteria for diagnosis were endoscopic or clinical evidence of ischemia, including bloody stools, in patients who died before diagnostic procedures were performed. Independent predictors of postoperative bowel ischemia were established using multivariable logistic regression analysis. Included were 7312 patients, with 6668 intact (67.0% EVAR) and 644 ruptured AAA repairs (31.5% EVAR). The incidence of bowel ischemia after intact repair was 1.6% (open repair, 3.6%; EVAR, 0.6%) and 15.2% after ruptured repair (open repair, 19.3%; EVAR, 6.4%). Ruptured AAA was the most important determinant of postoperative bowel ischemia (odds ratio [OR], 6.4, 95% confidence interval [CI], 4.5-9.0), followed by open repair (OR, 2.9; 95% CI, 1.8-4.7). Additional predictive patient factors were advanced age (OR, 1.4 per 10 years; 95% CI, 1.1-1.7), female gender (OR, 1.6; 95% CI, 1.1-2.2), hypertension (OR, 1.8; 95% CI, 1.1-3.0), heart failure (OR, 1.8; 95% CI, 1.2-2.8), and current smoking (OR, 1.5; 95% CI, 1.1-2.1). Other risk factors included unilateral interruption of the hypogastric artery (OR, 1.7; 95% CI, 1.0-2.8), prolonged operative time (OR, 1.2 per 60-minute increase; 95% CI, 1.1-1.3), blood loss >1 L (OR, 2.0; 95% CI, 1.3-3.0), and a distal anastomosis to the femoral artery (OR, 1.7; 95% CI, 1.1-2.7). Bowel ischemia patients had a significantly higher perioperative mortality after intact (open repair: 20.5% vs 1.9%; P < .001; EVAR: 34.6% vs 0.9%; P < .001) as well as after ruptured AAA repair (open repair: 48.2% vs 25.6%; P < .001; EVAR: 30.8% vs 21.1%; P < .001). This study underlines that although bowel ischemia after AAA repair is rare, the associated outcomes are very poor. The cause of postoperative bowel ischemia is multifactorial and can be attributed to patient factors and operative characteristics. These data should be considered during preoperative risk assessment and for optimization of both the patient and the procedure in an effort to reduce the risk of postoperative bowel ischemia.

Ultee KH ，Zettervall SL ，Soden PA ，Darling J ，Bertges DJ ，Verhagen HJ ，Schermerhorn ML ，Vascular Study Group of New England ... -  《-》

Outcomes of endovascular and open surgical repair of ruptured abdominal aortic aneurysms in elderly patients.

Endovascular aneurysm repair (EVAR) is becoming the preferred treatment modality for patients with a ruptured abdominal aortic aneurysm (rAAA). Although the survival advantage of EVAR over open aortic repair (OAR) has been shown in some studies, it is unclear whether this benefit extends to elderly patients. We sought to evaluate the outcomes of rAAA repair in octogenarians. We reviewed the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) data set (2005-2014) to identify patients older than 80 years who were treated with EVAR and OAR for rAAA. Procedural trends were evaluated during the course of the study period. Perioperative outcomes including mortality, morbidity, and hospital length of stay (LOS) were compared. Multivariable regression models were used to identify predictors of perioperative mortality and morbidity. Among 1048 elderly patients who underwent rAAA repair, 450 (43%) and 598 (57%) were treated with EVAR and OAR, respectively. The use of EVAR to treat rAAA had increased significantly in this population of patients (0% in 2005 vs 56% in 2014; P < .001). The overall 30-day mortality rate among octogenarians was 41%. The mortality rate was significantly higher among those treated with OAR compared with EVAR (47% vs 33%; P < .001). Pneumonia (21% vs 10%; P < .001), reintubation (14% vs 9%; P < .001), and >48-hour ventilator dependence (43% vs 21%; P < .001) were significantly higher in patients undergoing OAR. Hospital LOS (13 vs 10 days; P < .001) was also longer in the OAR cohort. Compared with EVAR, OAR was independently predictive of 30-day mortality (adjusted odds ratio [AOR], 1.7; 95% confidence interval [CI], 1.3-2.2; P < .001), pneumonia (AOR, 2.4; 95% CI, 1.7-3.6; P < .001), >48-hour ventilator dependence (AOR, 2.5; 95% CI, 1.8-3.3; P < .001), and longer LOS (adjusted mean ratio, 1.4; 95% CI, 1.2-1.6; P < .001). Elderly patients have significant but acceptable perioperative mortality and morbidity after rAAA repair. Use of endovascular repair in the elderly population has increased and is associated with better perioperative survival and 30-day outcomes compared with traditional open repair in this study.

Tan TW ，Eslami M ，Rybin D ，Doros G ，Zhang WW ，Farber A ... -  《-》

Outcomes for symptomatic abdominal aortic aneurysms in the American College of Surgeons National Surgical Quality Improvement Program.

Historically, symptomatic abdominal aortic aneurysms (AAAs) were found to have intermediate mortality compared with asymptomatic and ruptured AAAs; but with wider use of endovascular aneurysm repair (EVAR), a more recent study suggested that mortality of symptomatic aneurysms was similar to that of asymptomatic AAAs. These prior studies were limited by small numbers. The purpose of this study was to evaluate the mortality and morbidity associated with symptomatic AAA repair in a large contemporary population. All patients undergoing infrarenal AAA repair were identified in the 2011 to 2013 American College of Surgeons National Surgical Quality Improvement Program, vascular surgery targeted module. We excluded acute conversions to open repair and those for whom the surgical indication was embolization, dissection, thrombosis, or not documented. We compared 30-day mortality and major adverse events for asymptomatic, symptomatic, and ruptured AAA repair, stratified by EVAR and open repair, with univariate analysis and multivariable logistic regression. There were 5502 infrarenal AAAs identified, 4495 asymptomatic aneurysms (830 open repair, 3665 [82%] EVAR), 455 symptomatic aneurysms (143 open repair, 312 [69%] EVAR), and 552 ruptured aneurysms (263 open repair, 289 [52%] EVAR). Aneurysm diameter was similar between asymptomatic and symptomatic AAAs when stratified by procedure type, but it was larger for ruptured aneurysms (EVAR: symptomatic 5.8 ± 1.6 cm vs ruptured 7.5 ± 2.0 cm [P < .001]; open repair: symptomatic 6.4 ± 1.9 cm vs ruptured 8.0 ± 1.9 cm [P < .001]). The proportion of women was similar in symptomatic and ruptured AAAs (27% vs 23%, respectively; P = .14) but lower in asymptomatic AAAs (20%; P < .001). Symptomatic AAAs had intermediate 30-day mortality compared with asymptomatic and ruptured aneurysms after both EVAR (1.4% asymptomatic vs 3.8% symptomatic [P = .001]; symptomatic vs 22% ruptured [P < .001]) and open repair (4.3% asymptomatic vs 7.7% symptomatic [P = .08]; symptomatic vs 34% ruptured [P < .001]). After adjustment for age, gender, repair type, dialysis dependence, and history of severe chronic obstructive pulmonary disease, patients undergoing repair of symptomatic AAAs were twice as likely to die within 30 days compared with those with asymptomatic aneurysms (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.3-3.5). When stratified by repair type, the effect size and direction of the ORs were similar (EVAR: OR, 2.4 [95% CI, 1.2-4.7]; open repair: OR, 1.8 [95% CI, 0.86-3.9]) although not significant for open repair. Patients with ruptured aneurysms had a sevenfold increased risk of 30-day mortality compared with symptomatic patients (OR, 6.5; 95% CI, 4.1-10.6). Patients with symptomatic AAAs had a twofold increased risk of perioperative mortality compared with patients with asymptomatic aneurysms undergoing repair. Furthermore, patients with ruptured aneurysms have a sevenfold increased risk of mortality compared with patients with symptomatic aneurysms.

Soden PA ，Zettervall SL ，Ultee KH ，Darling JD ，Buck DB ，Hile CN ，Hamdan AD ，Schermerhorn ML ... -  《-》