Clinical effect of abdominal aortic aneurysm endografting: 7-year concurrent comparison with open repair

OBJECTIVE: We compared the effectiveness and clinical outcome of open repair versus endovascular aortic aneurysm repair (EVAR) in achieving prevention of abdominal aortic aneurysm (AAA)-related death and graft-related complications. METHODS: Over 7 years from 1997 to 2003, 1119 consecutive patients underwent elective treatment of infrarenal AAAs, 585 with open repair and 534 with EVAR. Patients were regularly followed up at 1, 6, 12 months, and every 6 months thereafter, in EVAR group, and at 3 and 12 months, and yearly thereafter after open repair. Preoperative, intraoperative, and follow-up data were stored in a prospective database. RESULTS: Median follow-up was similar in the 2 groups: 33 months (interquartile range [IQR], 13-50 months) in the EVAR group vs 35 months (IQR, 15-54 months) in the open repair group. EVAR group patients were older than patients in the open repair group: 73 years vs 72 years (P = .04). There were statistical significant differences between the EVAR group and the open repair group with respect to AAA median diameter (52 mm vs 56 mm), coronary disease rate (46% vs 37%; P = .001), pulmonary disease rate (56% vs 38%; P < .0001), and American Society of Anesthesiologists IV score rate (16% vs 6%; P < .0001). Thirty-day mortality in the EVAR group was 0.9% (5 of 534 patients), compared with 4.1% (24 of 585 patients; P = .001) in the open repair group, and major morbidity was 9.1% (49 of 534 patients) vs 18.6% (109 of 585 patients; P < .0001), respectively. The incidence of secondary procedures in the EVAR group was 15.7%, compared with 3% in the open repair group (P < .0001). There were no deaths related to secondary procedures in either group. Six AAAs (1.1%) ruptured after EVAR, 3 of which were fatal; in the open repair group 1 patient (0.2%) underwent successful repeat operatation to treat iliac pseudoaneurysm rupture 5 years after the original procedure. Kaplan-Meier estimates for freedom from aneurysm-related death at 84 months were 97.5% in the EVAR group and 95.9% in the open repair group (log rank test, P = .008). Kaplan-Meier survival estimates at 84 months were 67.1% in the open repair group and 66.9% in the EVAR group (P = NS). At the same interval the risk for secondary procedures was 49.4% for the EVAR group and 7.1% for the open repair group. Of the 11 variables analyzed with logistic analysis, open surgery (hazard ratio [HR], 11; 95% confidence interval [CI], 2.5-54.2; P = .002), American Society of Anesthesiologists IV score (HR, 7.1; 95% CI, 2.7-18.8; P = .0001), and age (HR, 1.06; 95% CI, 1.04-1.13; P = .04) were positive independent predictors of perioperative mortality. CONCLUSION: Our data suggest that at a maximum follow-up of 7 years, patients who undergo EVAR show lower perioperative and late aneurysm-related mortality compared with a younger and substantially healthier group of patients with aneurysms treated with open repair. The higher need for secondary procedures in the endovascular group did not affect superiority of the overall performance of EVAR in the early and late intervals.     

Sex differences in perioperative outcomes after complex abdominal aortic aneurysm repair

ObjectiveFemale sex is associated with worse outcomes after infrarenal abdominal aortic aneurysm (AAA) repair. However, the impact of female sex on complex AAA repair is poorly characterized. Therefore, we compared outcomes between female and male patients after open and endovascular treatment of complex AAA.MethodsWe identified all patients who underwent complex aneurysm repair between 2011 and 2017 in the American College of Surgeons National Surgical Quality Improvement Program targeted vascular module. Complex repairs were defined as those for juxtarenal, pararenal, or suprarenal aneurysms. We compared rates of perioperative adverse events between female and male patients stratified by open AAA repair and endovascular aneurysm repair (EVAR). We calculated propensity scores and used inverse probability-weighted logistic regression to identify independent associations between female sex and our outcomes.ResultsWe identified 2270 complex aneurysm repairs, of which 1260 were EVARs (21.4% female) and 1010 were open repairs (30.7% female). After EVAR, female patients had higher rates of perioperative mortality (6.3% vs 2.4%; P = .001) and major complications (15.9% vs 7.6%; P < .001) compared with male patients. In contrast, after open repair, perioperative mortality was not significantly different (7.4% vs 5.6%; P = .3), and the rate of major complications was similar (29.4% vs 27.4%; P = .53) between female and male patients. Furthermore, even though perioperative mortality was significantly lower after EVAR compared with open repair for male patients (2.4% vs 5.6%; P = .001), this difference was not significant for women (6.3% vs 7.4%; P = .60). On multivariable analysis, female sex remained independently associated with higher perioperative mortality (odds ratio [OR], 2.5; 95% confidence interval [CI], 1.3-4.9; P = .007) and major complications (OR, 2.0; 95% CI, 1.3-3.2; P = .002) in patients treated with EVAR but showed no significant association with mortality (OR, 0.9; 95% CI, 0.5-1.6; P = .69) or major complications (OR, 1.1; 95% CI, 0.8-1.5; P = .74) after open repair. However, the association of female sex with higher perioperative mortality in patients undergoing complex EVAR was attenuated when diameter was replaced with aortic size index in the multivariable analysis (OR, 1.9; 95% CI, 0.9-3.9; P = .091).ConclusionsFemale sex is associated with higher perioperative mortality and more major complications than for male patients after complex EVAR but not after complex open repair. Continuous efforts are warranted to improve the sex discrepancies in patients undergoing endovascular repair of complex AAA.     

Variation in postoperative complication rates after high-risk surgery in the United States

OBJECTIVE: Our goal was to characterize variation in complication rates across hospitals with differing volumes for select high-risk operations in the United States. METHODS: Data from the Nationwide Inpatient Sample for 1996 and 1997 were analyzed for 3 high-risk operations: esophagectomy (n=1,226), pancreatectomy (n=4,789), and intact abdominal aortic aneurysm repair (n=11,863). Complications evaluated included aspiration, cardiac complications, infection, pneumonia, pulmonary failure, renal failure, septicemia, and others. The risk of complications was calculated by hospital volume deciles, as well as for high-volume hospitals (HVH) and low-volume hospitals (LVH) defined by median hospital volume. RESULTS: Rates of any postoperative complication varied nearly 2-fold across hospital volume groups. The proportion of patients across hospital deciles having at least one complication ranged from 30% to 51% for esophageal resection, 6% to 12% for pancreatic resection, and 9% to 18% for abdominal aortic aneurysm repair. HVH had lower rates of one or more complications after pancreatic resection (OR, 0.71; 95% CI, 0.57 to 0.83; P=.002), esophageal resection (OR, 0.68; 95% CI, 0.52 to 0.90; P=.008), and intact abdominal aortic aneurysm (AAA) repair (OR, 0.67; 95% CI, 0.59 to 0.76; P<.001). Patients with one or more complications after pancreatic resection had a mortality of 18.8% versus only 5.2% for those without complications (P<.001). Esophageal resection mortality was 16.9% for patients with at least one complication and 2.5% for those without complications (P<.001) and AAA repair mortality was 10.4% for patients with at least one complication and 2.9% for those without complications (P<.001). CONCLUSIONS: High-risk operations have a decreased rate of postoperative complications when performed at HVH. Variation in complication rates may contribute to the volume-outcome relationship and provide a focus for quality improvement at LVH.     

Early outcomes of endovascular versus open abdominal aortic aneurysm repair in the National Surgical Quality Improvement Program-Private Sector (NSQIP-PS)

BACKGROUND: There remains no consensus on the appropriate application of endovascular abdominal aortic aneurysm repair (EVAR). Information from administrative databases, industry-sponsored trials, and single institutions has inherent deficiencies. This study was designed to compare early outcomes of open (OPEN) versus EVAR in a contemporary (2000 to 2003) large, multicenter prospective cohort. METHODS: Fourteen academic medical centers contributed data to the National Surgical Quality Improvement Program-Private Sector (NSQIP-PS), which ensures uniform, comprehensive, prospective, and previously validated data entry by trained, independent nurse reviewers. A battery of clinical and demographic features was assessed with multivariate analysis for association with the principal study end points of 30-day operative mortality and morbidity. RESULTS: One thousand forty-two patients underwent elective infrarenal abdominal aortic aneurysm (AAA) repairs: 460 EVAR and 582 OPEN. EVAR patients were older (74 vs 71 years, P < .0001), included more men (84.6% vs 79.6%, P < .05), and had a higher incidence of chronic obstructive pulmonary disease (25.4% vs 17.9%, P < .01). EVAR resulted in significantly reduced overall morbidity (24% vs 35%, P < .0001) and hospital stay (4 vs 9 days, P < .0001). Cardiopulmonary and renal function-related comorbidities had the expected significant impact on mortality for both procedures at univariate analysis ( P < .05). While crude mortality rates between EVAR and OPEN did not differ significantly (2.8% vs 4.0%) ( P = 0.32). After multivariate analysis, correlates of operative mortality included OPEN (odds ratio [OR], 2.44; 95% confidence interval [CI], 1.03 to 5.78; P < .05), advanced age (OR, 1.11; P < .001), history of angina (OR, 5.54; P < .01), poor functional status (OR, 5.78; P < .001), history of weight loss (OR, 7.42; P < .01), and preoperative dialysis (OR, 51.4; P < .0001). EVAR also compared favorably to OPEN (OR, 2.14; 95% CI, 1.58 to 2.89; P < .0001) for overall morbidity. CONCLUSION: Significant morbidity accompanies AAA repair, even at major academic medical centers. These data strongly endorse EVAR as the preferred approach in the presence of significant cardiopulmonary or renal comorbidities, or poor preoperative functional status.     

Graft dilatation following abdominal aortic aneurysm resection and grafting

BACKGROUND: It has been suggested that graft dilatation following repair of abdominal aortic aneurysm (AAA) is associated with complications such as anastomotic aneurysm and graft rupture. The purpose of the present study was to document the degree of dilatation observed in grafts after aneurysm repair and to correlate this with any graft-related complications. METHODS: Between January 1987 and December 1992, 219 patients had elective repair of their AAA at St George Hospital. A follow-up ultrasound scan was available for 154 of these patients. The following factors were examined: age, sex, size of aneurysm, type and size of graft, time of follow-up scan, size of graft at follow-up and any graft-related complications. RESULTS: The mean graft dilatation observed in knitted grafts (42.6%; 95% CI: 39.1-46.1%) was significantly greater than that observed for woven grafts (25.5%; 95% CI: 19.0-32.1%; P < 0.0001). There were no graft-related complications. CONCLUSIONS: Graft dilatation is a predictable phenomenon following AAA repair. It is more pronounced in knitted than in woven grafts, but does not necessarily lead to graft-related complications or failure.     

Colon ischemia following abdominal aortic aneurysm repair in the era of endovascular abdominal aortic repair

OBJECTIVE: To review, in the era of endovascular abdominal aortic repair (EVAR), the clinical spectrum of colonic ischemia (CI) following abdominal aortic aneurysm (AAA) repair and to assess the rate, overall mortality, and associated factors of occurrence. METHODS: Between 1995 and 2005, 1174 patients with infrarenal AAA were treated either by open surgery (n = 682) or by EVAR (n = 492). Preoperative risk factors, clinical presentation, intraoperative data, and early postoperative outcomes were prospectively assessed. Overt colonic ischemia as proven by colonoscopy and/or by operation was considered as a validating event and was correlated to collected variables. RESULTS: CI occurred in 34 patients (2.9%). Eighteen out of 34 (53%) patients died within 1 month. At 2 years, the survival rate was 35% in the CI group vs 86% in the non-CI group. Associated factors of occurrence of CI were: type of operation (open group = 27/682 [4%] vs EVAR = 7/492 [1.4%] [P = .01]), aneurysm rupture (11/88 [12.5%] vs 23/1086 [2.1%], P < .001), preoperative renal insufficiency (4/30 [13.3%] vs 29/1133 [3.1%], P = .01), preoperative respiratory insufficiency (8/157 [7%] vs 23/1005 [2%], P = .01), duration of operation (<2 hours [518] = 1.7%, between 2 to 4 hours [558] 2.9%, more than 4 hours [66] 13.6%, P = .001). Mean blood loss was greater in patients with CI (CI = 2000 ml [650-3350] than in those without CI = 1000 ml [500-1800] P = .008). Logistic regression analysis showed that rupture (OR 6.03 [interval of confidence (IC) 95% 2.68-13.5] P = .0001), duration of operation (OR 5.73 [IC 95% 2.06-15.9] P = .001) and creatinin > 200 mol/l (OR 4.67 [IC 95% 1.39-15.7] P = .028) were independent factors of CI. The mortality due to colonic ischemia was not statistically different between open surgery 14/27 (52%) and EVAR 4/7 (57%). CONCLUSION: CI remains a serious complication following AAA repair. In the univariate analysis, EVAR was associated with a lower rate of colonic ischemia. However, the logistic regression analysis showed that only rupture, long duration of operation, and prior renal disease were independently associated with CI. Within the two treatment modalities, the mortality rate remained identical.     

Fenestrated endovascular aneurysm repair is associated with lower perioperative morbidity and mortality compared with open repair for complex abdominal aortic aneurysms

ObjectiveThe Zenith Fenestrated Endovascular Graft (ZFEN; Cook Medical, Bloomington, Ind) has expanded the anatomic eligibility of endovascular aneurysm repair (EVAR) for complex abdominal aortic aneurysms (AAAs). Current data on ZFEN mainly consist of single-institution experiences and show conflicting results. Therefore, we compared perioperative outcomes after repair using ZFEN with open complex AAA repair and infrarenal EVAR in a nationwide multicenter registry.MethodsWe identified all patients undergoing elective AAA repair using ZFEN, open complex AAA repair, and standard infrarenal EVAR between 2012 and 2016 within the American College of Surgeons National Surgical Quality Improvement Program targeted vascular module. Open complex AAA repairs were defined as those with a juxtarenal or suprarenal proximal AAA extent in combination with an aortic cross-clamping position that was above at least one renal artery. The primary outcome was perioperative mortality, defined as death within 30 days or within the index hospitalization. Secondary outcomes included postoperative renal dysfunction (creatinine concentration increase of >2 mg/dL from preoperative value or new dialysis), occurrence of any complication, procedure times, blood transfusion rates, and length of stay. To account for baseline differences, we calculated propensity scores and employed inverse probability-weighted logistic regression.ResultsWe identified 6825 AAA repairs—220 ZFENs, 181 open complex AAA repairs, and 6424 infrarenal EVARs. Univariate analysis of ZFEN compared with open complex AAA repair demonstrated lower rates of perioperative mortality (1.8% vs 8.8%; P = .001), postoperative renal dysfunction (1.4% vs 7.7%; P = .002), and overall complications (11% vs 33%; P < .001). In addition, fewer patients undergoing ZFEN received blood transfusions (22% vs 73%; P < .001), and median length of stay was shorter (2 vs 7 days; P < .001). After adjustment, open complex AAA repair was associated with higher odds of perioperative mortality (odds ratio [OR], 4.9; 95% confidence interval [CI], 1.4-18), postoperative renal dysfunction (OR, 13; 95% CI, 3.6-49), and overall complication rates (OR, 4.2; 95% CI, 2.3-7.5) compared with ZFEN. Compared with infrarenal EVAR, ZFEN presented comparable rates of perioperative mortality (1.8% vs 0.8%; P = .084), renal dysfunction (1.4% vs 0.7%; P = .19), and any complication (11% vs 7.7%; P = .09). Furthermore, after adjustment, there was no significant difference between the odds of perioperative mortality, postoperative renal dysfunction, or any complication between infrarenal EVAR and ZFEN.ConclusionsZFEN is associated with lower perioperative morbidity and mortality compared with open complex AAA repair, and outcomes are comparable to those of infrarenal EVAR. Long-term durability of ZFEN compared with open complex AAA repair warrants future research.     

Perioperative outcomes after open and endovascular repair of intact abdominal aortic aneurysms in the United States during 2001

OBJECTIVE: Small patient numbers, mixed data from clinical trials, and longitudinal series representing institutional learning curves have characterized previous studies of early outcomes after endovascular abdominal aortic aneurysm (AAA) repair. We compared the perioperative outcomes of endovascular and open surgical AAA repair in an unselected sample of patients in a single calendar year using a national administrative database. METHODS: The 2001 National Inpatient Sample database was retrospectively reviewed. This database represents 20% of all-payer stratified sample of non-federal US hospitals. Patients older than 49 years were identified by primary diagnostic codes (International Classification of Disease, ninth revision [ICD-9], 441.4, intact, nonruptured AAA) and procedure codes (ICD-9 38.44 for open, 39.71 for endovascular repair). Patient demographic data (age, sex), comorbid conditions (ICD-9 coded), inpatient complications (ICD-9 coded), length of stay, final discharge disposition (home vs institution vs death), and hospital charges were examined with univariate and multivariate analyses. RESULTS: In calendar year 2001, 7172 patients underwent either open (64%) or endovascular (36%) repair of intact, nonruptured AAAs. Despite comparable rates of preoperative comorbid conditions and a greater proportion of octogenarians (23% vs 16%%; P =.0001), morbidity (18% vs 29%; P =.0001) and mortality (1.3% vs 3.8%; P =.0001) were significantly lower for endovascular repair than for open repair. The median length of stay (2 vs 7 days; P =.0001) and the rate of discharge to an institutional facility versus home (6% vs 14%; P =.0001) were also much lower in the endovascular group than in the open repair group. At multivariate analysis, open AAA repair and age older than 80 years were strong independent predictors (P =.0001 for all) for death (open repair: odds ratio [OR], 3.3; 95% confidence interval [CI], 2.3-4.9; age: OR, 14.2; 95% CI, 3.5-58.1), complications (open repair: OR, 1.9; 95% CI, 1.7-2.1; age: OR, 1.9; 95% CI, 1.5-2.5), and not being discharged to home (open repair: OR, 3.4; 95% CI, 2.9-4.1; age: OR, 12.0; 95% CI, 7.0-20.4). Mean hospital charges were significantly greater (difference, $3337; P =.0009) for endovascular repair than for open repair. Extrapolated to the total number of endovascular AAA repairs performed during the single 2001 calendar year, this resulted in a staggering $50.3 million in additional hospital charges. CONCLUSIONS: Endovascular repair of intact AAAs results in a significantly lower number of complications and deaths, shorter hospital stay, and improved likelihood of discharge to home, even in older patients, when compared with open surgical repair. These impressive gains in clinical outcome, however, are achieved at similarly impressive increases in health care costs.     

Does hostile neck anatomy preclude successful endovascular aortic aneurysm repair?

OBJECTIVES: Poor outcomes have been reported with endovascular aneurysm repair (EVAR) in patients with hostile neck anatomy. Unsupported endografts with active fixation may offer certain advantages in this situation. We compared EVAR results using the Ancure (Guidant) endograft in patients with and without hostile neck anatomy. METHODS: Records of EVAR patients from October 1999 to July 2002 at a tertiary care hospital were retrospectively reviewed from a division database. Patients with elective open abdominal aortic aneurysm (AAA) repair during the same period were reviewed to determine those unsuitable for EVAR. Hostile neck anatomy, assessed by computer tomography (CT) scans and angiograms, was defined as one or more of the following: (1) neck length 3 mm, (3) >2-mm reverse taper within 1 cm below the renal arteries, (4) neck thrombus > or =50% of circumference, and (5) angulation > or =60 degrees within 3 cm below renals. RESULTS: Three hundred and twenty-two patients underwent EVAR with an average follow-up of 18 months. Patients in Phase II trials (n = 41), repaired with other graft types (n = 48), or without complete anatomic records (n = 27) were excluded. Demographics and co-morbidities were similar in the 115 good-neck (GN) and 91 bad-neck (BN) patients except for age (mean, 72.9 years GN vs 75.7 BN; P = 0.13), gender (11% female GN vs 22% BN; P =.04); neck length (mean, 21.8 mm GN vs 14.4 mm BN: P <.001), and angulation (mean, 22 degrees GN vs 40 degrees BN; (P <.001). Perioperative mortality (0 GN vs 1.1% BN), late mortality (5.2% GN vs 4.4% BN), all endoleaks (19.1% GN vs 17.6% BN), proximal endoleaks (0.8% GN vs 2.1% BN), and graft migration (0 for both groups) did not reach statistical significance. Neck anatomy precluded EVAR in 106 of 165 (64%) patients with open AAA. CONCLUSIONS: Unsupported endografts with active fixation can yield excellent results in treating many medically compromised patients with hostile neck anatomy. Nonetheless, an unsuitable neck remains the most frequent cause for open abdominal AAA.     

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.

Long-term outcomes after endovascular abdominal aortic aneurysm repair: the first decade

OBJECTIVE: The proper role of endovascular abdominal aortic aneurysm repair (EVAR) remains controversial, largely due to uncertain late results. We reviewed a 12-year experience with EVAR to document late outcomes. METHODS: During the interval January 7, 1994 through December 31, 2005, 873 patients underwent EVAR utilizing 10 different stent graft devices. Primary outcomes examined included operative mortality, aneurysm rupture, aneurysm-related mortality, open surgical conversion, and late survival rates. The incidence of endoleak, migration, aneurysm enlargement, and graft patency was also determined. Finally, the need for reintervention and success of such secondary procedures were evaluated. Kaplan-Meier and multivariate methodology were used for analysis. RESULTS: Mean patient age was 75.7 years (range, 49-99 years); 81.4% were male. Mean follow-up was 27 months; 39.3% of patients had 2 or more major comorbidities, and 19.5% would be categorized as unfit for open repair. On an intent-to-treat basis, device deployment was successful in 99.3%. Thirty-day mortality was 1.8%. By Kaplan-Meier analysis, freedom from AAA rupture was 97.6% at 5 years and 94% at 9 years. Significant risk factors for late AAA rupture included female gender (odds ratio OR, 6.9; P = 0.004) and device-related endoleak (OR, 16.06; P = 0.009). Aneurysm-related death was avoided in 96.1% of patients, with the need for any reintervention (OR, 5.7 P = 0.006), family history of aneurysmal disease (OR, 9.5; P = 0.075), and renal insufficiency (OR, 7.1; P = 0.003) among its most important predictors. 87 (10%) patients required reintervention, with 92% of such procedures being catheter-based and a success rate of 84%. Significant predictors of reintervention included use of first-generation devices (OR, 1.2; P < 0.01) and late onset endoleak (OR, 64; P < 0.001). Current generation stent grafts correlated with significantly improved outcomes. Cumulative freedom from conversion to open repair was 93.3% at 5 through 9 years, with the need for prior reintervention (OR, 16.7; P = 0.001) its most important predictor. Cumulative survival was 52% at 5 years. CONCLUSIONS: EVAR using contemporary devices is a safe, effective, and durable method to prevent AAA rupture and aneurysm-related death. Assuming suitable AAA anatomy, these data justify a broad application of EVAR across a wide spectrum of patients.     

Comparison of the effects of open and endovascular aortic aneurysm repair on long-term renal function using chronic kidney disease staging based on glomerular filtration rate

OBJECTIVE: It has been suggested that endovascular aneurysm repair (EVAR) in concert with serial contrast-enhanced computed tomography (CT) surveillance adversely impacts renal function. Our primary objectives were to assess serial renal function in patients undergoing EVAR and open repair (OR) and to evaluate the relative effects of method of repair on renal function. METHODS: A thorough retrospective chart review was performed on 223 consecutive patients (103 EVAR, 120 OR) who underwent abdominal aortic aneurysm (AAA) repair. Demographics, pertinent risk factors, CT scan number, morbidity, and mortality were recorded in a database. Baseline, 30- and 90-day, and most recent glomerular filtration rate (GFR) were calculated. Mean GFR changes and renal function decline (using Chronic Kidney Disease [CKD] staging and Kaplan-Meier plot) were determined. EVAR and OR patients were compared. CKD prevalence (>or=stage 3, National Kidney Foundation) was determined before repair and in longitudinal follow-up. Observed-expected (OE) ratios for CKD were calculated for EVAR and OR patients by comparing observed CKD prevalence with the expected, age-adjusted prevalence. RESULTS: The only baseline difference between EVAR and OR cohorts was female gender (4% vs 12%, P = .029). Thirty-day GFR was significantly reduced in OR patients (P = .047), but it recovered and there were no differences in mean GFR at a mean follow-up of 23.2 months. However, 18% to 39% of patients in the EVAR and OR groups developed significant renal function decline over time depending on its definition. OE ratios for CKD prevalence were greater in AAA patients at baseline (OE 1.28-3.23, depending upon age group). During follow-up, the prevalence and severity of CKD increased regardless of method of repair (OE 1.8-9.0). Deterioration of renal function was independently associated with age >70 years in all patients (RR 2.92) and performance of EVAR compared with OR (RR 3.5) during long-term follow-up. CONCLUSIONS: Compared with EVAR, OR was associated with a significant but transient fall in GFR at 30 days. Renal function decline after AAA repair was common, regardless of method, especially in patients >70 years of age. However, the renal function decline was significantly greater by Kaplan-Meier analysis in EVAR than OR patients during long-term follow-up. More aggressive strategies to monitor and preserve renal function after AAA repair are warranted.     

Elective treatment of abdominal aortic aneurysm with endovascular or open repair: the first decade

OBJECTIVES: The development of endovascular aneurysm repair (EVAR) as an alternative to open repair of abdominal aortic aneurysms (AAA) has led to an increasing number of patients being treated by this less-invasive technique. It was anticipated that EVAR would reduce the operative mortality and morbidity compared with open repair. This study examined the initial 10-year experience in one center when both techniques were available to determine if there were advantages to one technique or the other, putting the results into the perspective of routine clinical care of patients with infrarenal AAA. METHODS: From June 1996 to May 2005, 677 patients underwent elective repair of their infrarenal AAA, of which 417 were treated with open repair and 260 by EVAR. Demographic and aneurysm-specific data, comorbidities, operative morbidity, mortality, and late outcome were analyzed. RESULTS: Open repair patients were 2 years younger (71 vs 74 years, P < .001), had larger aneurysms (6.01 +/- 1.38 cm vs 5.45 +/- 0.99 cm, P < .001), greater familial predisposition, a higher incidence of current smokers, and a higher incidence of chronic obstructive pulmonary disease than the EVAR group. There were no differences in renal function, hypertension, coronary artery disease, or heart failure between the two groups. Overall operative mortality was 3.1%; operative mortality per group was 3.5% for open and 2.7% for EVAR (P = .627). Procedure-related outcomes showed significant differences in operative blood loss and length of hospital stay in favor of EVAR, and 95% of the EVAR patients were discharged home vs 83% in the open repair group (P < .001). A Kaplan-Meier log-rank analysis showed no difference in early or long-term survival between open repair and EVAR (P = .20), but did show a difference in mid-term (3-year) survival favoring open repair (P < .002). Survival analysis by age (<70 and > or =70 years) showed no difference between treatment groups. CONCLUSIONS: Open repair and EVAR are both performed safely in patients treated for elective infrarenal AAA. EVAR has the perioperative advantages of reduced blood loss, reduced length of intensive care unit and hospital stay, and increased number of patients discharged to home. The mid-term survival advantage of open repair has been observed in other reports and deserves further study.     

Systematic review and meta-analysis of sex differences in outcomes after endovascular aneurysm repair for infrarenal abdominal aortic aneurysm

ObjectiveWomen face distinctive challenges when they receive endovascular aneurysm repair (EVAR) treatment, and according to the previous studies, sex differences in outcomes after EVAR for infrarenal abdominal aortic aneurysm (AAA) remains controversial. This study aimed to compare the short-term and long-term outcomes between women and men after EVAR for infrarenal AAA.MethodsWe conducted a comprehensive systematic review and meta-analysis of all available studies reporting sex differences after EVAR for infrarenal AAA, which were retrieved from the MEDICINE, Embase, and Cochrane Database. The pooled results were presented as odds ratios (ORs) for dichotomous data and hazard ratios for time-to-event data using a random effect model.ResultsThirty-six cohorts were included in this meta-analysis. The pooled results showed that women were associated with a significantly increased risk of 30-day mortality (crude OR, 1.67; 95% confidence interval [CI], 1.50-1.87; P < .001; adjusted OR, 1.73; 95% CI, 1.32-2.26; P < .001), in-hospital mortality (OR, 1.90; 95% CI, 1.43-2.53; P < .001), limb ischemia (OR, 2.44; 95% CI, 1.73-2.43; P < .001), renal complications (OR, 1.73; 95% CI, 1.12-2.67; P = .028), cardiac complications (OR, 1.68; 95% CI, 1.01-2.80; P = .046), and long-term all-cause mortality (hazard ratio, 1.23; 95% CI, 1.09-1.38; P = .001) compared with men; however, no significant sex difference was observed for visceral/mesenteric ischemia (OR, 1.62; 95% CI, 0.91-2.88; P = .098), 30-day reinterventions (OR, 1.37; 95% CI, 0.95-1.98; P = .095), late endoleaks (OR, 1.18; 95% CI, 0.88-1.56; P = .264), and late reinterventions (OR, 1.05; 95% CI, 0.78-1.41; P = .741). In the intact AAA subgroup, women had a significantly increased risk of visceral/mesenteric ischemia (OR, 1.85; 95% CI, 1.01-3.39; P = .046) and an equivalent risk of cardiac complications (OR, 1.64; 95% CI, 0.85-3.17; P = .138) compared with men.ConclusionsCompared with male sex, female sex is associated with an increased risk of 30-day mortality, in-hospital mortality, limb ischemia, renal complications, cardiac complications, and long-term all-cause mortality after EVAR for infrarenal AAA. Women should be enrolled in a strict and regular long-term surveillance after EVAR.     

Predictors of acute kidney injury after infrarenal abdominal aortic aneurysm repair in octogenarians

Objective

Acute kidney injury (AKI) is a common postoperative complication after abdominal aortic aneurysm (AAA) repair and is associated with significant morbidity and mortality. However, limited studies have investigated this complication in elderly patients. This study aims to evaluate AKI in octogenarians after open endovascular AAA repair (OAR) and endovascular AAA repair (EVAR).

Factors associated with symptomatic postoperative myocardial infarction after endovascular aneurysm repair

ObjectiveEndovascular aneurysm repair (EVAR) has now become the most common operation to treat abdominal aortic aneurysms (AAAs). One of the perceived benefits of EVAR over open AAA repair is reduced incidence of perioperative cardiac complications and mortality. The purpose of this study was to determine risk factors associated with postoperative myocardial infarction (POMI) in patients who have undergone EVAR.MethodsData were obtained from the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database for the years 2012 to 2015 in the Participant Use Data File. All patients in the database who underwent EVAR during this time were identified. These patients were then divided into two groups: those with POMI and those without. Bivariate analysis was done for preoperative, intraoperative, and postoperative risk factors, followed by multivariable analysis to determine associations of independent variables with POMI. A risk prediction model for POMI was created to accurately predict incidence of POMI after EVAR.ResultsA total of 7702 patients (81.3% male, 18.7% female) were identified who underwent EVAR from 2011 to 2015. Of these patients, 110 (1.4%) had POMI and 7592 (98.6%) did not. Several risk factors were related to an increased risk of POMI, including dependent functional health status, need for lower extremity revascularization, longer operation time, and ruptured AAA (P < .05, all).On multivariable analysis, the following factors were found to have significant associations with POMI: return to operating room (odds ratio [OR], 1.84; confidence interval [CI], 1.10-3.09; P = .020), ruptured AAA (OR, 1.87; CI, 1.18-2.95; P = .008), pneumonia (OR, 1.94; CI, 1.01-3.73; P = .048), age >80 years (compared with <70 years; OR, 2.30; CI, 1.36-3.86; P = .002), unplanned intubation (OR, 4.07; CI, 2.31-7.18; P < .001), and length of hospital stay >6 days (OR, 8.43; CI, 4.75-14.94; P < .001). The risk prediction model showed that in the presence of all these risk factors, the incidence of POMI was 58.3%. The incidence of cardiac arrest and death was significantly higher for patients with POMI compared with patients without POMI (cardiac arrest, 11.9% vs 1.3%; death, 10.2% vs 1.1%).ConclusionsIn patients who undergo EVAR, the risk of POMI is increased for those who are older, who present with a ruptured AAA, who have pneumonia, who have unplanned intubation, and who have prolonged hospital stay. Patients who suffer from POMI have higher risk of having cardiac arrest and death.     

Improving aneurysm-related outcomes: nationwide benefits of endovascular repair

OBJECTIVES: Endovascular aneurysm repair (EVAR) has changed the practice of abdominal aortic aneurysm (AAA) surgery. We examined a national Medicare database to establish the effect of EVAR introduction into the United States. METHODS: A 5% random sample of inpatient Medicare claims from 2000 to 2003 was queried using International Classification of Diseases, 9th Revision (ICD-9) diagnosis and procedure codes. An EVAR procedure code was available after October 2000. Occurrences were multiplied by 20 to estimate yearly national volumes and then divided into the yearly Centers for Medicare and Medicaid Services (CMS) population of elderly Medicare recipients for rates per capita, reported as cases per 100,000 elderly Medicare recipients. Statistical analysis was performed by using chi2, Student's t test, nonparametric tests, and multiple regression analysis, with significance defined as P < or = .05. RESULTS: Elective AAA repairs averaged 87.7 per 100,000 Medicare patients between 2000 and 2003, with EVAR has steadily increasing to 41% of elective repairs in 2003. From 2000 to 2003, overall elective AAA mortality declined from 5.0% to 3.7% (P < .001), while open repair mortality remained unchanged. EVAR patients are significantly older than patients treated with open repair. From 2000 to 2003 patients >84 years receiving EVAR increased to 62.7% (P < .001). Overall hospital length of stay (LOS) decreased from 8.6 days in 2000 to 7.3 days in 2003, P < .001, but increased for open AAA patients. EVAR patients were more likely to be discharged home rather than to skilled facilities. Average elective repair hospital charges were not different between groups, but Medicare reimbursement was lower for EVAR, with a higher proportion cases classified as DRG 111 (major cardiovascular procedure without complications). EVAR was used in 10.6% of ruptured AAA repairs in 2003, with a significant reduction in mortality compared with open repairs for rupture (31.8% vs 50.8%; P < .001). CONCLUSIONS: EVAR is replacing open surgery without an increase in overall case volume. EVAR is responsible for overall decrease in operative mortality even in ruptured aneurysms while decreasing utilization variables. Reimbursement to hospitals is shrinking, however.     

Surgeon specialty and provider volumes are related to outcome of intact abdominal aortic aneurysm repair in the United States

OBJECTIVE: This study was undertaken to determine the relative importance of surgeon specialty, hospital volume, and surgeon volume on outcome after abdominal aortic aneurysm (AAA) repair. METHODS: Data were reviewed for 3912 patients undergoing AAA repair in the Nationwide Inpatient Sample during 1997. In-hospital mortality was compared between high-volume hospitals and low-volume hospitals and between high-volume surgeons and low-volume surgeons. High-volume hospitals performed more than 35 AAA repairs per year, and high-volume surgeons performed more than 10 AAA repairs per year. Vascular, cardiac, and general surgery specialization was identified by analysis of other procedures performed by each surgeon. RESULTS: Overall, AAA repair mortality was 4.2%, and was lower at high-volume hospitals (3.0%) than at low-volume hospitals (5.5%) (P <.001). Lowest mortality was associated with operations performed by vascular surgeons (2.2%) compared with cardiac surgeons (4.0%) and general surgeons (5.5%) (P <.001). Mortality rates were also lower for high-volume hospitals (2.5%) compared with low-volume hospitals (5.6%) (P <.001). In a risk-adjusted analysis, high-volume hospital, vascular surgery specialty, and high-volume surgeon were all independently associated with lower risk of in-hospital mortality. In this analysis, risk reduction was 30% for high-volume hospitals (95% confidence interval [CI], 2%-51%; P <.05) and 40% for surgery by a high-volume surgeon (95% CI, 12%-60%; P =.01). AAA repair by general surgeons compared with vascular surgeons was associated with 76% greater risk for death (95% CI, 10%-190%; P =.02). No significant difference in mortality was found between cardiac and vascular surgeons. CONCLUSIONS: High surgeon volume and hospital volume of AAA repair were both associated with lower mortality compared with low-volume providers. Increased specialization in vascular surgery was associated with markedly decreased mortality independent of AAA repair volume. Health policy in support of selective referral for AAA repair should consider surgical specialization in addition to provider volume thresholds.     

Predictors of renal dysfunction after endovascular and open repair of abdominal aortic aneurysms

Objective

Renal complications after repair of abdominal aortic aneurysms (AAAs) have been associated with increased morbidity and mortality. However, limited data have assessed risk factors for renal complications in the endovascular era. This study aimed to identify predictors of renal complications after endovascular AAA repair (EVAR) and open repair.

Long-term durability of open abdominal aortic aneurysm repair

OBJECTIVE: In multiple comparisons of open vs endovascular (EVAR) repair of abdominal aortic aneurysms, the prior assumption that open repair produced superior durability has been challenged by advocates of EVAR. Although focus on EVAR reintervention has been intense, few contemporary studies document late outcomes after open repair; this was the goal of this study. METHODS: From January 1994 to December 1998 (chosen to ensure a minimum 5-year follow-up), 540 patients underwent elective open repair. Surveillance imaging (computed tomographic and magnetic resonance imaging scans) was obtained for 152 (57%) of the 269 patients who remained alive at a mean follow-up of 87 months. Study end points included freedom from graft-related interventions and aneurysm-related and overall survival (Kaplan-Meier test); factors predictive of these end points were determined by multivariate analysis. RESULTS: The mean age at operation was 73 years. A total of 76% of patients were male; 11% had renal insufficiency (creatinine > or =1.5 mg/dL), and 13% had chronic obstructive pulmonary disease. The aortic cross-clamp position was suprarenal in 135 (25%) patients, and 284 (53%) of patients had bifurcated grafts placed. Operative mortality (30 days) was 3%, and the median length of hospital stay was 7 days. Postoperative complications occurred in 68 (13%) patients. Predictors of postoperative complications included a history of myocardial infarction (hazard ratio [HR], 2.0; P = .01) and renal insufficiency (HR, 2.5; P = .02). The mean follow-up for all patients was 87 months. Actuarial survival was 70.7% +/- 2% and 44.3% +/- 2.4% at 5 and 10 years, respectively. Negative predictors of long-term survival included advanced age (HR, 1.1; P < .001), history of myocardial infarction (HR, 1.37; P = .02), and renal insufficiency (HR, 1.5; P = .04). Freedom from graft-related reintervention was 98.2% +/- 0.8% and 94.3% +/- 3.4% at 5 and 10 years, respectively. There were 13 late graft-related complications in 11 (2%) patients (mean follow-up, 7.2 years). Findings included seven anastomotic pseudoaneurysms (five were repaired), four graft limb occlusions, and two graft infections. Aneurysms were identified in noncontiguous arterial segments in 68 (45%) of 152 patients, most of which involved the iliac arteries and required no treatment because of small size. Late aortic aneurysms proximal to the repair were identified in 24% of patients, and 29 (19%) patients had multiple late synchronous aneurysms. CONCLUSIONS: Open repair remains a safe and durable option for the management of abdominal aortic aneurysms, with an excellent associated 10-year survival in patients who undergo operation at 75 years of age or younger. In addition, the freedom from graft-related reintervention is superior to that of EVAR. Finally, continued surveillance after open repair is appropriate and should be directed toward the detection of other aneurysms.