Outcomes after elective abdominal aortic aneurysm repair in obese versus nonobese patients.

Obesity is a worldwide epidemic, particularly in Western society. It predisposes surgical patients to an increased risk of adverse outcomes. The aim of our study was to use a nationally representative vascular database and to compare in-hospital outcomes in obese vs nonobese patients undergoing elective open aortic repair (OAR) and endovascular aneurysm repair (EVAR). All patients undergoing elective abdominal aortic aneurysm repair were identified in the Vascular Quality Initiative database (2003-2017). Obesity was defined as body mass index ≥30 kg/m2. Univariable (Student t-test and χ2 test) and multivariable (logistic regression) analyses were implemented to compare in-hospital mortality and any major complications (wound infection, renal failure, and cardiopulmonary failure) in obese vs nonobese patients. We identified a total of 33,082 patients undergoing elective OAR (nonobese, n = 4605 [72.4%]; obese, n = 1754 [27.6%]) and EVAR (nonobese, n = 18,338 [68.6%]; obese, n = 8385 [31.4%]). Obese patients undergoing OAR and EVAR were relatively younger compared with nonobese patients (mean age [standard deviation], 67.55 [8.26] years vs 70.27 [8.30] years and 71.06 [8.22] years vs 74.55 [8.55] years), respectively; (both P < .001). Regardless of approach, obese patients had slightly longer operative time (OAR, 259.02 [109.97] minutes vs 239.37 [99.78] minutes; EVAR, 138.27 [70.64] minutes vs 134.34 [69.98] minutes) and higher blood loss (OAR, 2030 [1823] mL vs 1619 [1642] mL; EVAR, 228 [354] mL vs 207 [312] mL; both P < .001). There was no significant difference in mortality between the two groups undergoing OAR and EVAR (OAR, 2.9% vs 3.2% [P = .50]; EVAR, 0.5% vs 0.6% [P = .76]). On multivariable analysis, obese patients undergoing OAR had 33% higher odds of renal failure (adjusted odds ratio [OR], 1.33; 95% confidence interval [CI], 1.09-1.63; P = .006) and 75% higher odds of wound infections (adjusted OR, 1.75; 95% CI, 1.11-2.76; P = .02) compared with nonobese patients. However, in patients undergoing EVAR, no association was seen between obesity and any major complications. A significant interaction was found between obesity and surgical approach in the event of renal failure, in which obese patients undergoing OAR had significantly higher odds of renal failure compared with those in the EVAR group (ORinteraction, 1.36; 95% CI, 1.05-1.75; P = .02). Using a large nationally representative database, we demonstrated an increased risk of renal failure and wound infections in obese patients undergoing OAR compared with nonobese patients. On the other hand, obesity did not seem to increase the odds of major adverse outcomes in patients undergoing EVAR. Further long-term prospective studies are needed to verify the effects of obesity after abdominal aortic aneurysm repair and the implications of these findings in clinical decision-making.

Locham S ，Rizwan M ，Dakour-Aridi H ，Faateh M ，Nejim B ，Malas M ... -  《-》

Open Abdominal Aortic Aneurysm Repair Is Associated with Higher Mortality Among Nonobese Patients and Higher Risk of Deep Wound Infections Among Obese Patients.

Prevalence of obesity in the United States is increasing. The impact of obesity on outcomes after endovascular and open abdominal aortic aneurysm (AAA) repair is largely unknown. The purpose of this analysis was to compare the postoperative outcomes between obese and nonobese patients after these operations. The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from years 2013-2015 was analyzed. Preoperative, intraoperative, and postoperative variables were compared between obese and nonobese patient groups. Then obese and nonobese patients were divided into 2 groups each, based on the type of surgery (endovascular repair of abdominal aortic aneurysms (EVAR) versus. open AAA repair), and the outcomes were compared. Then multivariant analysis was used to compare impact of operative modality on outcomes for obese and nonobese patients. A total of 6,859 patients (men 80%, women 20%) underwent surgical procedures for AAA during this time period. Among these patients, 2,218 (32.3%) had body mass index (BMI) ≥30, and 4,641 (67.7%) had BMI <30. Obese patients were less likely to be > 80 years old, women, nonwhites, and smokers. Obese patients had lower mortality and higher risk of deep wound infections after surgery (P < 0.05). Among the obese patients, 83.1% underwent EVAR and 16.9% underwent open AAA repair; patients undergoing EVAR had shorter operative times, shorter length of hospital stays, and mortality (P < 0.05). Among nonobese patients, 81% underwent EVAR and 19% underwent open AAA repair. Patients undergoing EVAR had shorter duration of operation, length of hospital stay, and mortality (P < 0.05). Overall, mortality was the highest among nonobese patients undergoing open AAA repair (odds ratio (OR) 0.66, confidence interval (CI) 0.44-0.99, P < 0.05). Incidence of deep wound infections was the highest among obese patients undergoing open AAA repair (OR 4.3, CI: 1.2-14.6, P < 0.05). Nonobese patients have high mortality after open AAA repair, and obese patients have higher incidence of deep wound infections after open AAA repair. For patients deemed appropriate anatomic candidates, EVAR should be preferred for nonobese patients to improve mortality and for obese patients to reduce the incidence of deep wound infections.

Aziz F ，Lehman EB 《-》

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 ... -  《-》

Octogenarians Undergoing Open Repair Have Higher Mortality Compared with Fenestrated Endovascular Repair of Intact Abdominal Aortic Aneurysms Involving the Visceral Vessels.

Prior studies have shown that octogenarians have a higher risk of mortality than nonoctogenarians undergoing open aneurysm repair (OAR) and endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm (AAA). Fenestrated endovascular aneurysm repair (F-EVAR) was approved by the Food and Drug Administration (FDA) in 2012 and has been used as a less invasive approach to treat patients with suboptimal neck anatomy with favorable outcomes compared with traditional OAR. The aim of the study is to compare 30-day outcomes of F-EVAR versus OAR in octogenarians undergoing repair of AAA involving the visceral vessels in the United States. All patients with postoperative diagnosis of nonruptured AAA repair were identified in the National Surgical Quality Improvement Program database (2006-2015). Univariate and multivariate analyses were implemented to examine 30-day morbidity and mortality adjusting for patient demographics and comorbidities. A total of 548 octogenarians underwent repair of nonruptured AAA involving the visceral vessels, of which 242 (44%) were F-EVARs, and 306 (56%) were OARs. Octogenarians undergoing F-EVAR were on average 1-year older (median age [interquartile range]: 83 [82, 86] versus 82 [81, 85], P = 0.004) and more likely to be male (82% vs. 64%, P < 0.001) compared with OAR. Prevalence of diabetes (13% vs. 6%, P = 0.005) and progressive renal failure (57% vs. 47%, P = 0.03) was also higher in patients undergoing F-EVAR compared with OAR. Thirty-day postoperative mortality was higher after OAR (8.5% vs. 4.1%, P = 0.04). Secondary outcomes including cardiopulmonary (27.1% vs. 5.8%, P < 0.001) and renal injury (10.8% vs. 2.1%, P < 0.001) were also significantly higher in OAR compared with F-EVAR. After adjusting for patients' demographics and comorbidities, OAR had almost 4-fold increased risk of 30-day postoperative mortality compared with F-EVAR (odds ratio [95% confidence interval]: 3.90 [1.48-10.31], P = 0.006). In this large national cohort of octogenarians undergoing repair for complex AAA's, we showed that F-EVAR is associated with significantly lower postoperative morbidity and mortality than open repair. One of the main limitations of the study is the lack of anatomical data. However, despite that, our findings support the shifting paradigm toward minimally invasive approach in this frail population for treatment of complex AAA's. Further studies are needed to evaluate the long-term benefit of any repair in octogenarians.

Locham S ，Faateh M ，Dakour-Aridi H ，Nejim B ，Malas M ... -  《-》

Anemia and postoperative outcomes after open and endovascular repair of intact abdominal aortic aneurysms.

Anemia is associated with increased cardiac adverse events during the early postoperative period because of high physiologic stress and increased cardiac demand. The aim of this study was to assess the surgical outcomes and prognostic implications of anemia in patients undergoing repair of intact abdominal aortic aneurysms (AAAs). A retrospective analysis of all patients who underwent open aortic repair (OAR) or endovascular aneurysm repair (EVAR) in the Vascular Quality Initiative database (2008-2017) was performed. Patients with preoperative polycythemia, patients with ruptured aneurysms, and patients transfused with >4 units of packed red blood cells were excluded. Hemoglobin levels were categorized into three groups: moderate-severe anemia (<10 g/dL), mild anemia (10-12 g/dL in women and 10-13 g/dL in men), and no anemia (>12 g/dL in women and >13 g/dL in men). Multivariate logistic models and coarsened exact matching were used to analyze the association between anemia and 30-day mortality and between anemia and major in-hospital complications after OAR and EVAR. A total of 34,397 patients were identified undergoing AAA repair. Of those, 28.5% had mild anemia and 4.3% had moderate-severe anemia. In both OAR (n = 6112) and EVAR (n = 28,285), patients with moderate-severe anemia had significantly higher rates of in-hospital adverse events, such as in-hospital mortality, myocardial infarction, renal and respiratory complications, and reoperation, compared with patients with mild or no anemia. They also had higher rates of 30-day mortality. After multivariate analysis and 1:1 coarsened exact matching, no association was found between anemia and 30-day mortality and other in-hospital outcomes in patients undergoing OAR. On the other hand, in EVAR, moderate-severe anemia was associated with 2.7 times the odds of 30-day mortality (odds ratio [OR], 2.65; 95% confidence interval [CI], 1.69-4.18), 2.5 times the odds of renal complications (OR, 2.47; 95% CI, 1.78-3.43; P < .05), and twice the risk of acute congestive heart failure (OR, 1.96; 95% CI, 1.18-3.25) and respiratory complications (OR, 2.01; 95% CI, 1.26-3.19). Mild anemia was also associated with increased odds of 30-day mortality and renal and respiratory complications in patients undergoing EVAR. Interestingly, preoperative blood transfusion in mildly anemic patients undergoing EVAR was associated with double the odds of in-hospital major adverse cardiac events (stroke, death, and myocardial infarction; OR, 2.1; 95% CI, 1.38-3.11; P < .001). Preoperative anemia is associated with higher odds of 30-day mortality and in-hospital adverse outcomes after EVAR but not after OAR. These findings highlight the need to incorporate anemia into the preoperative risk assessment of patients undergoing EVAR. Future studies are needed to assess the efficacy of medical therapies in improving postoperative outcomes in anemic patients undergoing AAA repair.

Dakour-Aridi H ，Nejim B ，Locham S ，Alshwaily W ，Malas MB ... -  《-》