Epidemiology of surgically treated abdominal aortic aneurysms in the United States, 1988 to 2000

Abdominal aortic aneurysm (AAA) repair is a complex procedure about which little information exists regarding trends in surgical practice in the United States. This study was undertaken to define benchmark data regarding performance and outcomes of conventional AAA repair that might be used in comparisons with endovascular AAA repair data. Patients undergoing repair of intact (n = 87,728) or ruptured (n = 16,295) AAAs in the Nationwide Inpatient Sample (NIS) for 1988 to 2000 were studied. The NIS represents a 20% stratified random sample of all discharges from US hospitals. Unadjusted and case mix-adjusted analyses of in-hospital mortality and length of stay were performed. The overall frequency of intact AAA repair remained relatively stable during the study period, ranging from 18.1 to 16.3 operations/100,000 adults between 1988 and 2000, respectively. The operative mortality rate for intact AAA repair decreased significantly (p < .001) from 6.5% in 1988 to 4.3% in 2000. Length of stay following intact AAA repair also declined significantly (p < .001) from a median of 11 days in 1988 (interquartile range [IQR] 9-15 days) to 7 days in 2000 (IQR 5-10 days). The incidence of ruptured AAA repair decreased significantly (p < .001) from 4.2 to 2.6 operations/100,000 adults between 1988 and 2000, respectively. Mortality for ruptured AAA repair, averaging 45.6%, did not decrease significantly during the study period. Intact AAA repair by conventional means has become increasingly safe, with decreased operative mortality and shorter hospital stays. Ruptured AAA repair by conventional means has not become safer but has decreased in incidence, suggesting possible reductions in risk factors contributing to rupture, coupled with more timely intact AAA repairs.     

Age stratified, perioperative, and one-year mortality after abdominal aortic aneurysm repair: a statewide experience

OBJECTIVE: The purpose of this study was to determine the in-hospital, 30-day, and 365-day mortality for the open repair of abdominal aortic aneurysms (AAAs), when stratified by age, in the general population. Age stratification could provide clinicians with information more applicable to an individual patient than overall mortality figures. METHODS: In a retrospective analysis, data were obtained from the California Office of Statewide Health Planning and Development (OSHPD) for the years 1995 to 1999. Out-of-hospital mortality was determined via linkage to the state death registry. All patients undergoing AAA repair as coded by International Classification of Diseases, 9th Revision (ICD-9) procedure code 38.44 and diagnosis codes 441.4 (intact) and 441.3/441.5 (ruptured) in California were identified. Patients <50 years of age were excluded. We determined in-hospital, 30-day, and 365-day mortality, and stratified our findings by patient age. Multivariate logistic regression was used to determine predictors of mortality in the intact and ruptured AAA cohorts. RESULTS: We identified 12,406 patients (9,778 intact, 2,628 ruptured). Mean patient age was 72.4 +/- 7.2 years (intact) and 73.9 +/- 8.2 (ruptured). Men comprised 80.9% of patients, and 90.8% of patients were white. Overall, intact AAA patient mortality was 3.8% in-hospital, 4% at 30 days, and 8.5% at 365 days. There was a steep increase in mortality with increasing age, such that 365-day mortality increased from 2.9% for patients 51 to 60 years old to 15% for patients 81 to 90 years old. Mortality from day 31 to 365 was greater than both in-hospital and 30-day mortality for all but the youngest intact AAA patients. Perioperative (in-hospital and 30-day) mortality for ruptured cases was 45%, and mortality at 1 year was 54%. CONCLUSIONS: There is continued mortality after the open repair of AAAs during postoperative days 31 to 365 that, for many patients, is greater than the perioperative death rate. This mortality increases dramatically with age for both intact and ruptured AAA repair.     

Epidemiology and Outcome of Aortic Aneurysms in Hong Kong

Abstract The objective of this study was to determine epidemiology and mortality statistics for abdominal aortic aneurysms (AAAs) in Hong Kong. Data from three sources were obtained and analyzed: (1) Hong Kong Hospital Authority discharge statistics for 1999 and 2000; (2) a survey on aortic aneurysms in public hospitals conducted by the Working Group of Vascular Surgery; and (3) the Department of Surgery, University of Hong Kong Medical Center aortic aneurysm database. The disease pattern, distribution, and operative mortality were determined. The annual incidence of AAA in Hong Kong is 13.7 per 100,000 population and 105 per 100,000 for those aged 65 and above. About 10% of the AAAs that presented were ruptured. The mean age of the AAA patients was 74 years, with 84% of them over age 65. The operative repair rate for AAAs was low, being only 8% for intact aneurysms and 54% for ruptured ones. Overall, 45% of all aneurysm repairs were performed for a ruptured AAA. There is diverse practice between major vascular centers and smaller regional hospitals. The territory-wide operative mortality rates for intact and ruptured aneurysms were 10% (range 4–24%) and 70% (range 38––100%), respectively. There was no gender bias in the rupture and operative rates. The overall mortality was 17% for intact AAAs and 78% for ruptured AAAs. The average length of hospital stay was 19 days for elective AAA surgery and 13 days for ruptured AAAs. The number of operations in high-volume centers is increasing with a concomitant decrease in operative mortality. There are no definitive data to indicate that the incidence of AAAs is rising, but a trend toward an increasing number of operations in referral centers is noted. The low repair rates for intact AAAs and the high proportion of repairs for ruptured aneurysms suggest that AAAs are undertreated in Hong Kong.     

Meta-analysis and systematic review of the relationship between volume and outcome in abdominal aortic aneurysm surgery

BACKGROUND: This study investigated the volume-outcome relationship for abdominal aortic aneurysm (AAA) surgery and quantified critical volume thresholds. METHODS: PubMed, EMBASE and the Cochrane library were searched for articles on the operation volume-outcome relationship in elective and ruptured AAA surgery. UK Hospital Episode Statistics data were also considered. Elective and ruptured AAA repairs were dealt with separately. The data were meta-analysed, and the odds ratios (95 per cent confidence interval) for mortality at higher- and lower-volume hospitals were compared. Volume thresholds were identified from each paper. RESULTS: The analysis included 421,299 elective and 45,796 ruptured AAA operations. Significant relationships between mortality and annual volume were noted for both groups. Overall, the weighted odds ratio was 0.66 (0.65 to 0.67) for elective repair at a threshold of 43 AAAs per annum and 0.78 (0.73 to 0.82) for ruptured aneurysm repair at a threshold of 15 AAAs per annum, both in favour of high-volume institutions. CONCLUSION: Higher annual operation volumes are associated with significantly lower mortality in both elective and ruptured AAA repair. This suggests that AAA surgery should be performed only at higher-volume centres.     

Surgical volume and quality of care for esophageal resection: do high-volume hospitals have fewer complications?

BACKGROUND: Previous studies have shown that high-volume hospitals (HVHs) have lower mortality rates than low-volume hospitals (LVHs). However, little is known regarding the relationship of morbidity to hospital volume. The objective of the current study was to investigate the relative incidence of postoperative complications after esophageal resection at HVHs and LVHs. METHODS: All patients discharged from a nonfederal, acute-care hospital in Maryland after esophageal resection from 1994 to 1998 were included (n = 366). Rates of 10 postoperative complications were compared at HVHs and LVHs. Risk-adjusted analyses were performed using multiple logistic regression. RESULTS: High-volume hospitals had a mortality rate of 2.5% compared with 15.4% at LVHs (p < 0.001), with a case-mixed adjusted odds ratio (OR) of death equal to 5.7 (95% confidence interval [CI], 2.0 to 16; p < 0.001). Low-volume hospitals had a profound increase in the risk of several complications after adjusting for case-mix: renal failure (OR, 19; 95% CI, 1.9 to 178; p = 0.01), pulmonary failure (OR, 4.8; 95% CI, 1.6 to 14; p = 0.002), septicemia (OR, 4.0; 95% CI, 1.1 to 15; p = 0.04), reintubation (OR, 2.9; 95% CI, 1.4 to 6.1; p = 0.004), surgical complications (OR, 3.3; 95% CI, 1.6 to 6.9; p = 0.001), and aspiration (OR, 1.8; 95% CI, 1.0 to 3.3; p = 0.04). CONCLUSIONS: Patients undergoing esophageal resection at LVHs were at a markedly increased risk of postoperative complications and death. Pulmonary complications are particularly prevalent at LVHs and contribute to the death of patients having surgery at those centers.     

Epidemiological study of the relationship between volume and outcome after abdominal aortic aneurysm surgery in the UK from 2000 to 2005

BACKGROUND: The aim was to assess the relationship between hospital volume and outcome after abdominal aortic aneurysm (AAA) surgery in the UK. METHODS: Hospital Episode Statistics (2000-2005) were classified as elective, urgent or ruptured AAA repair. Analysis was by modelling of mortality rate, complication rate and length of hospital stay with regard to the annual operative volume, after risk adjustment. RESULTS: There were 112,545 diagnoses, or repairs, of AAAs, of which 26,822 were infrarenal aneurysms. The mean mortality rate was 7.4, 23.6 and 41.8 per cent for elective, urgent and ruptured AAA repair respectively. Elective AAA repair undertaken at high-volume hospitals showed volume-related improvements in mortality (P < 0.001). Patients were discharged from hospital earlier (P < 0.001). The critical volume threshold was 32 elective AAA repairs per year. For urgent repair, patients at high-volume hospitals had a reduced mortality rate (P = 0.017) with an increased length of stay (P = 0.041). There was no relationship between volume and outcome for ruptured AAA repairs. CONCLUSION: Increased annual volumes were associated with significant reductions in mortality for elective and urgent AAA repair, but not for repair of ruptured AAAs.     

Surgical repair of bladder exstrophy in the modern era: contemporary practice patterns and the role of hospital case volume

PURPOSE: Bladder exstrophy is a rare condition, and data are lacking regarding practice patterns in its surgical management. We used a large nationwide database to investigate practice patterns of bladder exstrophy repair. MATERIALS AND METHODS: We used the Nationwide Inpatient Sample (1988 to 2000) to identify patients who underwent surgical repair of bladder exstrophy (International Classification of Disease-9 code 578.6). We analyzed factors affecting practice patterns and outcomes. Hospital volume was based on caseload during the highest volume year of study participation (high volume 5 or more, mid volume 3 to 4 and low volume less than 3 cases). RESULTS: We identified 407 cases. Approximately half of the patients (53.2%) were hospitalized within 24 hours of birth, although 28% of patients were older than 1 year. Of the patients 54% were male. Exstrophy repair is extremely resource intensive. In this series mean length of hospital stay (LOS) was 24.6 +/- 22.8 days, and mean inflation adjusted hospital charges were 62,302 dollars (median 39,978 dollars). High volume hospitals (HVHs) had lower hospital charges (37,370 dollars) than mid volume (51,778 dollars) or low volume hospitals (LVHs, 50,474 dollars, p = 0.0095). On multivariate regression HVHs had lower charges even after controlling for other significant predictors, including LOS (p <0.0001). Patients at HVHs were more likely to undergo osteotomy (p = 0.007). Six patients died after exstrophy repair (1.5%), all of whom had been born prematurely (p <0.0001). Although death was more likely at LVHs, this was due to the fact that more patients at LVHs were born prematurely (4.2% at HVHs vs 5.9% at mid volume hospitals and 11.1% at LVHs, p = 0.027). CONCLUSIONS: Bladder exstrophy repair carries a high risk of morbidity and is resource intensive. Variations between high and low volume hospitals in practice patterns and case mix may contribute to observed differences in resource use, LOS and clinical outcomes.     

Ruptured inflammatory abdominal aortic aneurysm: insights in clinical management and outcome

BACKGROUND: Ruptured inflammatory abdominal aortic aneurysm (AAA) is relatively rare, and little has been written on the outcome of operative treatment. METHODS: Patients undergoing attempted repair of ruptured inflammatory AAA between 1995 and 2001 were included in a retrospective case-cohort study. Demographic, clinical, and operative factors were analyzed, together with in-hospital morbidity, in-hospital mortality, and duration of postoperative hospital stay. RESULTS: Of 297 patients who underwent attempted operative repair of ruptured AAA, 24 (8%) had an inflammatory aneurysm. Twenty-two patients were men, and two were women; median age was 69 years (range, 51-85 years). Operative findings revealed a contained hematoma in 16 patients (70%), free rupture in 3 patients (13%), aortocaval fistula in 4 patients (17%), and aortoenteric fistula in 1 patient (4%). Of 273 noninflammatory ruptured AAAs, only 2 AAA (1%) were associated with primary aortic fistula. Ten patients (42%) with inflammatory AAA died in hospital, compared with 117 of 273 patients (43%) without inflammation. Median postoperative stay was 10 days (range, 0-35 days). Of the 14 patients with inflammatory lesions who survived, 11 had postoperative complications; 4 patients had acute renal failure, three of whom required temporary renal replacement therapy. CONCLUSIONS: Ruptured inflammatory AAA is associated with a higher incidence of aortic fistula than is ruptured noninflammatory AAA. Repair of ruptured inflammatory AAA is not associated with increased operative mortality compared with repair of ruptured noninflammatory AAA.     

Size and location of thrombus in intact and ruptured abdominal aortic aneurysms

PURPOSE: This study compared the volume and morphology of intraluminal thrombus (ILT) in intact and ruptured abdominal aortic aneurysms (AAAs). METHODS: ILT volume in 67 intact AAAs and in 31 ruptured AAAs was assessed by using computed tomography (CT) angiography to measure the major and minor diameter of the outer wall and lumen of AAA as outlined by contrast at multiple sites. ILT thrombus morphology was recorded by AutoCAD 2000 software. Four equidistant images traced from the CT scan were recorded along the length of AAA. Thrombus volume was categorized as anterior-eccentric if the calculated area of thrombus was greater anteriorly, posterior-eccentric if greater posteriorly, eccentric-equal if the difference between the anterior and posterior thrombus was 相似文献   

Payer status is related to differences in access and outcomes of abdominal aortic aneurysm repair in the United States

BACKGROUND: The hypothesis of this study was that differences exist among patients with private insurance compared with patients with Medicaid or no insurance, regarding access to the timely treatment of abdominal aortic aneurysms (AAAs) and the outcomes of AAA repair. METHODS: The study comprised 5363 patients aged less than 65 years (mean age, 59 years) with a diagnostic code for intact or ruptured AAA and a procedure code for AAA repair in the National Inpatient Sample for 1995 to 2000. Dependent variables included ruptured AAA, intact AAA, and in-hospital postoperative mortality rates. Independent variables included payer status, median income, race, gender, age, and comorbid disease. Risk-adjusted analyses were performed with the use of binary logistic regression. RESULTS: AAA rupture was most likely (P <.001) to affect patients with no insurance (36%) or Medicaid (18%), compared with patients with private insurance (13%). After an adjustment for case-mix had been made, data showed that patients without insurance had an increased risk of rupture compared with patients with private insurance (odds ratio, 2.3; 95% CI, 1.5-3.5; P <.001). Operative mortality rates after elective AAA repair were greater (P =.04) for patients with no insurance (2.6%) or Medicaid (2.7%), compared with patients with private insurance (1.2%). Similarly, operative mortality rates for AAA repair after rupture were greater (P =.001) in patients without insurance (45.3%) or Medicaid (31.3%), compared with patients with private insurance (26.2%). CONCLUSIONS: Uninsured patients more often seek treatment of ruptured AAAs compared with patients with private insurance. Operative mortality rates in uninsured patients are greater for elective and emergent AAA repair. These data support the tenet that payer status is associated with mortality rates after AAA repair.     

Payer status is related to differences in access and outcomes of abdominal aortic aneurysm repair in the United States: Boxter LK,Dimick JB,Wainess RM,et al. Surgery 2003;134L:142-5

ConclusionThere were greater operative mortality rates in uninsured patients for both elective and emergent abdominal aortic aneurysm (AAA) repair. Uninsured patients underwent treatment for ruptured AAAs more often than did patients with private insurance.SummaryThe authors studied whether patients with private insurance, compared with patients with Medicaid or no insurance, differ with respect to outcome of AAA repair and timely access to treatment of AAA.The national inpatient procedure diagnostic codes for AAA repair, intact and ruptured, were examined for 5363 patients younger than 65 years, from 1995 to 2000, with risk-adjusted analyses for access to AAA treatment and outcomes of repair. Dependent variables included in-hospital mortality, ruptured AAA, and intact AAA. Independent variables were comorbid disease, gender, age, race, payer status, and median income.Patients with no insurance or Medicaid were more likely to have AAA rupture (P < .001). Patients without insurance were at increased risk for rupture compared with patients with private insurance (odds ratio, 2.3; 95% confidence interval, 1.5-3.5; P < .001). Operative mortality rates appeared greater after elective AAA repair in patients with no insurance or Medicaid compared with patients with private insurance. Operative mortality rates were also higher after ruptured AAA repair in patients without insurance or Medicaid.CommentAdditional analyses are needed to determine whether patients without insurance or with Medicaid tend to avoid health care because of the financial burden or whether delayed access to surgical treatment results from gate-keeping issues or other deterrents to health care among patients with no insurance or Medicaid.     

Systemic Inflammation and Repair of Abdominal Aortic Aneurysm

Background Inflammation is integral to the pathogenesis of abdominal aortic aneurysm (AAA). This study examines preoperative biomarkers of systemic inflammation in patients undergoing open repair of intact and ruptured AAA. Methods One-hundred twelve patients were entered into a prospective observational study. Preoperative POSSUM physiology score, C-reactive protein (CRP), white blood count (WBC), platelet count, fibrinogen, and albumin were recorded and related to clinical variables using univariate analysis. Results Sixty-one patients with a ruptured AAA, 39 with an asymptomatic intact AAA, and 12 with an acutely symptomatic intact AAA underwent attempted repair. There were two inflammatory asymptomatic aneurysms and one inflammatory ruptured aneurysm. No patient had clinical evidence of coexistent inflammatory disease. Patients with a symptomatic intact AAA had a significantly greater level of CRP and fibrinogen, higher WBC, and lower serum albumin, than those with an asymptomatic intact AAA. Patients with a ruptured aneurysm had a significantly greater level of CRP, higher WBC, and lower serum albumin than those with an asymptomatic intact aneurysm. Patients with a symptomatic intact AAA had a significantly higher CRP level, but lower WBC, than those with a ruptured AAA. There was no difference in CRP level, WBC, or serum albumin between survivors and non-survivors of attempted repair of asymptomatic, symptomatic and ruptured AAA. Conclusions Acutely symptomatic and ruptured AAAs are associated with an early elevation in systemic inflammatory biomarkers. This early activation of the inflammatory response might influence perioperative outcome. Presented to the Association of Surgeons of Great Britain & Ireland Annual Meeting, Edinburgh, 2006, and published in abstract form in Br J Surg 2006; 93 (S1):126–127.     

The effect of secondary operations on mortality following abdominal aortic aneurysm repair in the United States: 1988-2001

Certain complications following open repair of abdominal aortic aneurysms (AAAs) require additional operations or invasive procedures. The purpose of this study was to determine the effect of secondary interventions on mortality rate following open repair of intact and ruptured AAAs in the United States. Clinical data on 98,193 patients treated from 1988 to 2001 with an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) primary procedure code 38.44 (resection of the abdominal aorta with replacement) were analyzed. Demographic factors, types of secondary interventions, and in-hospital mortality rates were assessed by univariate and multivariate logistic regression analysis (SPSS Version 11.0, Chicago, IL). The database utilized in this study was The Nationwide Inpatient Sample (NIS). The mortality rate was 4.5% in the intact AAA group and 45.5% in the ruptured AAA group. The rate of secondary operations and procedures was much higher in the ruptured AAA group, especially related to renal failure (5.52% vs 1.49%, p <0.001); respiratory failure (3.67% vs 0.71%, p <0.001); postoperative bleeding (2.41% vs 0.81%, p <0.001); or colonic ischemia (2.38% vs 0.36%, p <0.001). Increased mortality following open repair of intact AAAs accompanied: peripheral artery angioplasty/stenting (OR, 1.25; 95% CI, 1.04-1.51; p = 0.018); coronary artery angioplasty/stenting (OR, 1.68; 95% CI, 1.05-2.70; p = 0.031); inferior vena cava (IVC) filter placement (OR, 2.02; 95% CI, 01.31-3.1; p = 0.001); vascular reconstruction or thromboembolectomy (OR, 2.05; 95% CI, 1.9-2.22; p <0.001); lower extremity amputation (OR, 4.09; 95% CI, 2.78-6.0; p <0.001); coronary artery bypass (OR, 6.71; 95% CI, 3.74-12.03; p <0.001); operations for postoperative bleeding (OR, 6.92; 95% CI, 5.71-8.4; p <0.001); initiation of hemodialysis (OR, 10.52; 95% CI, 9.22-12.01; p <0.001); tracheostomy (OR, 11.9; 95% CI, 9.86-14.37; p <0.001); and colectomy (OR, 16.22; 95% CI, 12.55-20.95; p <0.001). Increased risk of mortality following open repair of ruptured AAAs accompanied the following: operations for postoperative bleeding (OR, 1.5; 95% CI, 1.22-1.85; p <0.001); colectomy (OR, 1.63; 95% CI, 1.32-2.01; p <0.001); and initiation of hemodialysis (OR, 2.66; 95% CI, 2.30-3.08; p <0.001). The only independent variable in this group associated with decreased risk of in-hospital mortality was IVC filter placement (OR, 0.41; 95% CI, 0.27-0.64; p <0.001). This study confirms the perception that additional operations or invasive procedures following open repair of AAA entail significantly worse in-hospital mortality rates, especially when related to colonic ischemia, respiratory failure, and renal failure.     

To what extent has endovascular aneurysm repair influenced abdominal aortic aneurysm management in the state of Illinois?

PURPOSE: This study was performed using population-based data to determine the changing trends in the techniques for abdominal aortic aneurysm (AAA) repair in the state of Illinois during the past 9 years and to examine the extent to which endovascular aneurysm repair (EVAR) has influenced overall AAA management. METHODS: All records of patients who underwent AAA repair (1995 to 2003 inclusive) were retrieved from the Illinois Hospital Association COMPdata database. The outcome as determined by in-hospital mortality was analyzed according to intervention type (open vs EVAR) and indication (elective repair vs ruptured AAA). Data were stratified by age, gender, and hospital type (university vs community setting) and then analyzed using both univariate (chi 2 , t tests) and multivariate (stepwise logistic regression) techniques. RESULTS: Between 1995 and 2003, 14,517 patients underwent AAA repair (85% for elective and 15% for ruptured AAA). The average age was 71.4 +/- 7.9 years, and 76% were men. For elective cases, open repair was performed in 86% and EVAR in 14%; and for ruptured cases, open repair in 97% and EVAR in 3%. Elective EVAR was associated with lower in-hospital mortality compared with open repair regardless of age. No differences were observed with age after either type of repair for a ruptured aneurysm. Men had a lower in-hospital mortality compared with women for open repair of both elective and ruptured aneurysms. For EVAR, the mortality of an elective repair was lower in men, but there was no difference after a ruptured AAA. In men, the difference in mortality between elective open repair and EVAR was significant; the type of institution did not influence outcome. Patients >80 years of age had a higher mortality after open repair for both elective and ruptured AAA and after EVAR of a ruptured AAA. The average length of stay was 9.9 days for open elective repair, 13.1 days after open repair of a ruptured AAA, and 3.6 days for EVAR. The independent predictors of higher in-hospital mortality were female gender, age >80 years, diagnosis (ruptured vs open), and procedure (open vs EVAR). The year of the procedure and type of hospital (university vs community) were not predictive of outcome. CONCLUSIONS: EVAR has had a significant impact on AAA management in Illinois over a relatively short time period. In this population-based review, EVAR was associated with a significantly decreased in-hospital mortality and length of stay. Octogenarians had higher mortality after both types of repair, with the exception of elective EVAR.     

Endovascular aneurysm repair at 5 years: does aneurysm diameter predict outcome?

OBJECTIVE: The appropriate size threshold for endovascular repair of small abdominal aortic aneurysms (AAA) is unclear. We studied the outcome of endovascular aneurysm repair (EVAR) as a function of preoperative aneurysm diameter to determine the relationship between aneurysm size and long-term outcome of endovascular repair. METHODS: We reviewed the results of 923 patients treated in a prospective, multicenter clinical trial of EVAR. Small aneurysms were defined according to two size thresholds of 5.5 cm and 5.0 cm. Two-way analysis was used to compare patients with small aneurysms (<5.5 cm, n = 441) to patients with large aneurysms (> or =5.5 cm, n = 482). An ordered three-way analysis was used to compare patients with small AAA (<5.0 cm, n = 145), medium AAA (5.0 to 5.9 cm, n = 461), and large AAA (> or =6.0 cm, n = 317). The primary outcome measures of rupture, AAA-related death, surgical conversion, secondary intervention, and survival were compared using Kaplan-Meier estimates at 5 years. RESULTS: Median aneurysm size was 5.5 cm. The two-way comparison showed that 5 years after EVAR, patients with small aneurysms (<5.5 cm) had a lower AAA-related death rate (1% vs 6%, P = .006), a higher survival rate (69% vs 57%, P = .0002), and a lower secondary intervention rate (25% vs 32%, P = .03) than patients with large aneurysms (> or =5.5 cm). Three-way analysis revealed that patients with small AAAs (<5.0 cm) were younger (P < .0001) and were more likely to have a family history of aneurysm (P < .05), prior coronary intervention (P = .003), and peripheral occlusive disease (P = .008) than patients with larger AAAs. Patients with smaller AAAs also had more favorable aortic neck anatomy (P < .004). Patients with large AAAs were older (P < .0001), had higher operative risk (P = .01), and were more likely to have chronic obstructive pulmonary disease (P = .005), obesity (P = .03), and congestive heart failure (P = .004). At 5 years, patients with small AAAs had better outcomes, with 100% freedom from rupture vs 97% for medium AAAs and 93% for large AAAs (P = .02), 99% freedom from AAA-related death vs 97% for medium AAAs and 92% for large AAAs (P = .02) and 98% freedom from conversion vs 92% for medium AAAs and 89% for large AAAs (P = .01). Survival was significantly improved in small (69%) and medium AAAs (68%) compared to large AAAs (51%, P < .0001). Multivariate Cox proportional hazards modeling revealed that aneurysm size was a significant independent predictor of rupture (P = .04; hazard ratio [HR], 2.195), AAA-related death (P = .03; HR, 2.007), surgical conversion (P = .007; HR, 1.827), and survival (P = .001; HR, 1.351). There were no significant differences in secondary intervention, endoleak, or migration rates between small, medium, and large AAAs. CONCLUSIONS: Preoperative aneurysm size is an important determinant of long-term outcome following endovascular repair. Patients with small AAAs (<5.0 cm) are more favorable candidates for EVAR and have the best long-term outcomes, with 99% freedom from AAA death at 5 years. Patients with large AAAs (> or =6.0 cm) have shorter life expectancy and have a higher risk of rupture, surgical conversion, and aneurysm-related death following EVAR compared to patients with smaller aneurysms. Nonetheless, 92% of patients with large AAAs are protected from AAA-related death at 5 years. Patients with AAAs of intermediate size (5 to 6 cm) represent most of the patients treated with EVAR and have a 97% freedom from AAA-related death at 5 years.     

Comparison of morphologic features of intact and ruptured aneurysms of infrarenal abdominal aorta

INTRODUCTION: Endovascular aneurysm repair (EVAR) has been suggested as a technique to improve outcome of ruptured abdominal aortic aneurysm (AAA). Whether this technique becomes an established treatment will depend, in part, on the anatomy of ruptured AAA. METHODS: The anatomy of intact and ruptured AAA seen in a university department of vascular surgery over 5 years was reviewed. Aneurysm anatomy was assessed with spiral computed tomographic angiography. Suitability for EVAR was assessed from the dimensions of the proximal neck and common iliac arteries. Neck length less than 15 mm, neck width greater than 30 mm, and common iliac artery diameter greater than 22 mm were declared unsuitable for EVAR. RESULTS: Three hundred sixty-three patients with intact AAA and 46 with ruptured AAA were identified. Larger intact aneurysms were significantly associated with longer renal artery-bifurcation distance and more complex proximal neck architecture. In this sample, patients with ruptured AAA were more likely to have larger aneurysms with shorter and narrower proximal necks. Significantly more intact aneurysms were morphologically suitable for endovascular repair compared with ruptured AAA (78% vs 43%; P <.001). CONCLUSIONS: Ruptured AAA are less likely to be suitable for endovascular repair than are intact AAA, most probably because of larger diameter at presentation. Open repair will likely remain the treatment of choice in most patients with ruptured AAA, because of current morphologic constraints of endovascular repair.     

Hospital vascular surgery volume and procedure mortality rates in California, 1982-1994

Purpose: Little is known about the long-term growth and outcomes of vascular surgery procedures over time. Trends in the use of three major vascular surgery procedures by a general population—lower extremity arterial bypass (LEAB), carotid endarterectomy (CEA), and abdominal aortic aneurysm repair (AAA)—are described. The extent to which these procedures are being performed in low-, moderate-, and high-volume hospitals is examined. Methods: California hospital discharge records for LEAB, CEA, AAA, lower extremity angioplasty, coronary angioplasty, and coronary bypass surgery (CABG) were studied in all non-federal hospitals between 1982 and 1994. The data were age- and sex-adjusted to describe procedure growth. In-hospital mortality rates for LEAB, CEA, and AAA are related to overall hospital procedure volume, using logistic regression to control for risk factors and time trends. Results: Growth in the number of vascular procedures performed in California was modest between 1982 and 1994, with no age-adjusted growth. Lower extremity angioplasty grew considerably in the 1980s and has since plateaued. Annual in-hospital death rates declined for all procedures except ruptured AAA. Comparing the two 5-year periods of 1982–1986 and 1990–1994, in-hospital death rates decreased from 4.2% to 3.3% for LEAB, from 9.2% to 6.2% for unruptured AAA, and from 1.6% to 1.0% for CEA (p < 0.0001). The odds of dying for patients treated in high-volume hospitals for LEAB and CEA procedures compared with patients treated in hospitals performing fewer than 20 procedures in a year were 66.7% (p = < 0.0001) and 66.1% (p < 0.0001), respectively. For patients with ruptured and unruptured AAA procedures, the odds of dying in hospitals with at least 50 AAA procedures in a year were 49.1% (p < 0.0001) and 83.8% (p = 0.016), respectively, compared with the odds of dying in low-volume hospitals. Conclusions: In-hospital mortality rates for CEA, LEAB, and unruptured AAA have been significantly decreasing over time. Mortality is inversely related to hospital volume and directly related to patient age and emergency status. Mortality trends over time for ruptured AAA remains unchanged; however, mortality is less in high-volume hospitals. Coronary angioplasty (PTCA) has not had an impact on rates for LEAB. (J Vasc Surg 1998;28:45-58)     

Prognosis of patients turned down for conventional abdominal aortic aneurysm repair in the endovascular and sonographic era: Szilagyi revisited?

PURPOSE: The United Kingdom Small Aneurysm study has demonstrated the low risk of rupture in aneurysms less than 5.5 cm in diameter. With the advent of endoluminal techniques, patients considered unfit to undergo laparotomy are now considered for endovascular repair. However, the natural history of aneurysms larger than 5.5 cm remains uncertain, especially when severe comorbidity is present. In our center, we prospectively maintain records of all patients for whom elective aneurysm surgery was refused. This study documented the outcome of all patients referred with abdominal aortic aneurysms (AAAs) larger than 5.5 cm in diameter who were turned down for elective open repair and determined the cause of death and risk of rupture in all patients. METHODS: Details of all patients with AAAs from January 5, 1989, to January 5, 1999, were recorded, and demographic details on all patients with AAAs larger than 5.5 cm were collected. Copies of death certificates were obtained from the Office of National Statistics, local in-hospital patient records, and general practitioner records. Results of postmortem examinations were also obtained. Aneurysms were stratified according to their size at presentation (5.5-5.9 cm, 6.0-7.0 cm, and > 7.0 cm), and the reasons no intervention was made were documented. RESULTS: A total of 106 patients were turned down for elective aneurysm surgery in the 10-year period (10.6 per year). The mean age of the patients was 78.4 years (SD, 7.4), and 70 were men and 36 were women. At the end of the study, 76 patients (71.7%) had died. Overall, the 3-year survival rate was 17%. Patients with AAAs larger than 7.0 cm lived a median of 9 months. A ruptured aneurysm was certified as a cause of death in 36% of the patients with an AAA of 5.5 to 5.9 cm, in 50% of the patients with an AAA of 6 to 7.0 cm, and 55% of the patients with an AAA larger than 7.0 cm. Reasons given for not intervening were patient refusal (31 cases), the patient being "unfit for surgery" (18 cases), the "advanced age" of the patient (18 cases), cardiac disease (9 cases), cancer (9 cases), respiratory disease (6 cases), and other (15 cases). CONCLUSION: Although we recognize the problems with death certification, we found that rupture was a significant cause of death in patients with an untreated AAA that was larger than 5.5 cm. Although little difference in outcome was observed in aneurysms in the 5.5 to 7.0 cm size range, patients with an AAA that was larger than 7.0 cm seemed to have a much poorer prognosis.     

The impact of gender on presentation, therapy, and mortality of abdominal aortic aneurysm in the United States, 2001-2004

INTRODUCTION: The elective repair of abdominal aortic aneurysms (AAA) may decrease a patient's risk of rupture and confers a significantly lower in-hospital mortality rate than emergency repair. Previous works have shown that AAA rupture rates are higher in women compared to men, and that women have higher associated in-hospital mortality rates. This study was performed to evaluate, currently, to what extent patient gender influences presentation and treatment of AAA and the associated outcomes in the United States. METHODS: The Nationwide Inpatient Sample was used, with pertinent ICD-9 codes, to identify all patient-discharges that occurred with the primary diagnosis of intact (iAAA) or ruptured/dissecting (rAAA) abdominal aortic aneurysms between the years 2001 and 2004. Univariate and multiple logistic regression analyses of variables were performed. RESULTS: An estimated 220,403 AAA patient-discharges were identified during the study period. 37,016 (17%) patients presented with rAAA. A higher percentage of women with AAA presented with rupture compared to men (21% vs 16%; odds ratio [OR] 1.40, 95% confidence interval [CI], 1.27-1.54). This rupture rate did not significantly change from 2001 to 2004 (P = .85 for trend). For iAAA, women had higher odds of in-hospital mortality than men (OR 1.60; 95% CI, 1.24-2.07). Compared to men, in-hospital mortality rates for women with iAAA were higher for both endovascular (2.1% vs 0.83%, P < .0001) and open repairs (6.1% vs 4.0%, P < .0001). For iAAA, fewer women underwent endovascular repair (32.4% vs 46.7%, P < .0001; O.R. 0.59, 95% CI, 0.52-0.67). For patients who presented with rAAA, women were less likely to undergo surgical intervention compared to men (59% vs 70%, P < .0001). For those that underwent repair, women had higher in-hospital mortality rates than men (43% vs 36%, P < .0001; OR 1.49, 95% CI, 1.16-1.91). CONCLUSION: A higher percentage of women currently present with aneurysm rupture. They have higher in-hospital mortality rates for both iAAA and rAAA. This gender difference in the outcomes following repair of abdominal aortic aneurysm has persisted over time, the cause of which is not explained by these or previous data, a fact that warrants further investigation.     

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.