Surgical repair of ruptured abdominal aortic aneurysms in the state of Maryland: factors influencing outcome among 527 recent cases

The cost-effectiveness of repairing ruptured abdominal aortic aneurysms

BACKGROUND

Although advances in technology have reduced the operative risk of elective abdominal aortic aneurysm (AAA) repair, the surgical repair of ruptured AAAs is associated with a much poorer prognosis and a higher cost. Accordingly, it has been suggested that patients with predictably high rates of morbidity and mortality from ruptured AAA may not benefit from surgical intervention.

METHODS AND RESULTS

A cost-effectiveness analysis was performed with the use of a Markov decision-analytic model to compute long-term survival in quality-adjusted life years and lifetime costs for a hypothetical cohort of patients with ruptured AAAs managed with either a strategy of open surgical repair or no intervention. Probability estimates for the various outcomes were based on a review of the literature. Average costs of (1) the immediate hospitalization ($28,356) and (2) complications resulting from the procedure were based on the average use of resources as reported in the literature and from a hospital's cost accounting system. Our measure of outcome was the incremental cost-effectiveness ratio. For our base-case analysis, the repair of ruptured AAAs was cost-effective with an incremental cost-effectiveness ratio of $10,754. (Society is usually willing to pay for interventions with cost-effectiveness ratios of less than $60,000; for example, the costeffectiveness ratios for coronary artery bypass grafting and dialysis are $9500 and $54,400, respectively.) In sensitivity analyses, the cost-effectiveness of repairing ruptured AAAs was influenced only by alterations in the operative mortality. If the operative mortality exceeded 88%, repair of ruptured AAAs was no longer cost-effective. As an independent variable, increasing age had no substantial impact on the cost-effectiveness, although it is reported to be associated with increased operative mortality. It was necessary that the patient's cost of the initial hospitalization for ruptured AAA exceed $195,000 before repairing ruptured AAAs was no longer cost-effective.

CONCLUSIONS

Our analysis suggests that despite the high cost and poor outcomes, the surgical repair of ruptured AAAs is still cost-effective when compared with no intervention. The cost of repairing ruptured AAAs falls within society's acceptable limits and therefore should not be a consideration in the management of patients with AAAs.

The influence of gender on outcome after ruptured abdominal aortic aneurysm

BACKGROUND

The influence of gender on the management of coronary artery disease is well documented, but few reports exist regarding the influence of gender on the management of peripheral arterial disease.

OBJECTIVE

The purpose of this study was to examine the influence of gender on selection for and short-term and long-term outcomes of repair of ruptured abdominal aortic aneurysm (RAAA) in a regional vascular surgery unit.

METHODS

Analysis of the prospectively gathered Lothian Surgical Audit database identified 692 patients (542 male and 150 female) admitted with RAAA between January 1, 1983, and December 31, 1995. Case notes were reviewed for patients who were admitted but not operated on. Operative mortality was defined as death within the same hospital admission. Long-term survival data were obtained from the General Register Office (GRO1 records) through record linkage by the Information and Statistics Division of the National Health Service of Scotland.

RESULTS

A total of 542 men (78%; median age, 72 years; age range, 46-93 years) and 150 women (22%; median age, 74 years; age range, 55-93 years) were admitted with RAAA (P =.12; Mann-Whitney U test). There was no significant difference in perioperative mortality between men and women. Although women who were not operated on (median age, 81 years; age range, 68-93 years) were significantly (P =.005) older than men who were not operated on (median age, 77 years; age range, 54-93 years), for any given age group, women appeared less likely than men to be offered surgical repair. Long-term survival after successful repair was comparable for the genders.

CONCLUSIONS

Gender has no influence on either short-term or long-term outcome for patients undergoing operative repair of RAAA. However, women are less likely to be selected for operation than their male counterparts.

Results of elective abdominal aortic aneurysm repair in the 1990s: A population-based analysis of 2335 cases

OBJECTIVE

The safety and efficacy of conventional abdominal aortic aneurysm (AAA) repair are undergoing increased examination in parallel with the development of less invasive repair methods. Because most published studies of elective AAA repair report operations performed in tertiary referral institutions and thus may not reflect the outcome in the surgical community at large, the current population-based study was undertaken to document the results obtained across a broad spectrum of clinical practice in a defined geographic area and to examine the factors that influence the outcomes.

METHODS

The Maryland Health Services Cost Review Commission database was used to identify all the elective AAA repairs that were performed in all the nonfederal acute care hospitals in the state from 1990 to 1995.

RESULTS

Elective AAA repair was performed on 2335 patients (mean age, 70.4 years) in 46 of the 52 (88%) nonfederal acute care hospitals in the state, including seven high-volume (>100 cases), nine moderate-volume (50 to 99 cases), and 30 low-volume (<50 cases) institutions. The in-hospital mortality rate was 3.5% and increased significantly with advancing age: less than 65 years, 2.2%; 65 to 69 years, 2.5%; 70 to 79 years, 3.5%; and more than 80 years, 7.3% (P =.002). Mortality rates were higher for women (4.5% vs 3.2%; P =.17), for blacks (6.7% vs 3.2%; P =.046), and for patients with renal failure (11.8% vs 3. 4%; P =.11) but not for patients with hypertension, diabetes, heart disease, and pulmonary disease. The operative mortality rate was inversely correlated with hospital volume (4.3% in low-volume hospitals, 4.2% in moderate-volume hospitals, and 2.5% in high-volume hospitals; P =.08), although no differences were noted in the mean ages or comorbidity levels of patients who underwent operations in these three hospital populations. The operative mortality rate was inversely correlated with the experience of the individual surgeon: one case, 9.9%; two to nine cases, 4.9%; 10 to 49 cases, 2.8%; 50 to 99 cases, 2.9%; and more than 100 cases, 3.8% (P =.01). Multivariate analysis results identified patient age (P =. 002), low hospital volume (P =.039), and very low surgeon volume (P =.01) as independent predictors of operative mortality. The mean length of stay and mean hospital charges were 10.6 days and $17,589 and decreased with increasing surgeon volume: one case, 22.7 days/$32,800; two to nine cases, 10.6 days/$18,509; 10 to 49 cases, 10.0 days/$16,611; 50 to 99 cases, 10.9 days/$17,843; and more than 100 cases, 9.6 days/$16,682 (P <.0001/P <.0001).

CONCLUSION

Elective AAA repair is a safe procedure in contemporary practice in Maryland. Operative risk is increased among the elderly and when operations are performed by surgeons with very low volumes or in low-volume hospitals. Hospital lengths of stay were shorter and charges were lower when elective AAA repair was performed by surgeons with higher volumes.

The association between preoperative patient characteristics and both clinical and economic outcomes after abdominal aortic surgery

OBJECTIVE

To evaluate the association between patient characteristics and both clinical and economic outcomes in patients having abdominal aortic surgery in Maryland between 1994 and 1996.

DESIGN

Retrospective study using an administrative data set.

SETTING

All Maryland hospitals that performed abdominal aortic surgery from 1994 through 1996 (n = 46).

PARTICIPANTS

All patients who had abdominal aortic surgery in Maryland from 1994 through 1996 (n = 2,987).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The authors obtained discharge abstracts from the Maryland Health Services Cost Review Commission for patients with a primary procedure code for abdominal aortic surgery. Primary outcome variables were in-hospital mortality, hospital length of stay, and intensive care unit (ICU) days. The authors evaluated the following groups of independent variables: demographic characteristics, severity of illness, comorbid disease, and preoperative admission days. In multivariate analysis, independent predictors of in-hospital mortality were age 61 to 70 years (odds ratio [OR], 3.1; confidence interval [CI], 1.4 to 6.9), age 71 to 84 years (OR, 7.2; CI, 3.7 to 14.1), age 85 years or older (OR, 9.3; CI, 3.9 to 21.9), ruptured aneurysm (OR, 5.3; CI, 3.5 to 8.2), urgent operation (OR, 2.3; CI, 1.1 to 5.2), emergent operation (OR, 3.0; CI, 1.9 to 4.7), mild liver disease (OR, 4.6; CI, 2.0 to 10.9), and chronic renal disease (OR, 6.9; CI, 3.9 to 12.1). Hospital admission 1 to 2 days preoperatively was not associated with a difference in in-hospital mortality but was associated with a 31% increase in hospital days (CI, 23% to 40%) and a 38% increase in ICU days (CI, 19% to 60%).

CONCLUSION

In patients having aortic surgery, several patient characteristics such as mild liver disease and chronic renal failure, were associated with increased in-hospital mortality and length of stay. The practice of admitting patients to the hospital 1 to 2 days before surgery should be reevaluated because this was not associated with reduced in-hospital mortality but was associated with increased hospital and ICU stay.

Hospital volume can serve as a surrogate for surgeon volume for achieving excellent outcomes in colorectal resection

OBJECTIVE

To examine the association of surgeon and hospital case volumes with the short-term outcomes of in-hospital death, total hospital charges, and length of stay for resection of colorectal carcinoma.

METHODS

The study design was a cross-sectional analysis of all adult patients who underwent resection for colorectal cancer using Maryland state discharge data from 1992 to 1996. Cases were divided into three groups based on annual surgeon case volume--low (< or =5), medium (5 to 10), and high (>10)--and hospital volume--low (<40), medium (40 to 70), and high (> or =70). Poisson and multiple linear regression analyses were used to identify differences in outcomes among volume groups while adjusting for variations in type of resections performed, cancer stage, patient comorbidities, urgency of admission, and patient demographic variables.

RESULTS

During the 5-year period, 9739 resections were performed by 812 surgeons at 50 hospitals. The majority of surgeons (81%) and hospitals (58%) were in the low-volume group. The low-volume surgeons operated on 3461 of the 9739 total patients (36%) at an average rate of 1.8 cases per year. Higher surgeon volume was associated with significant improvement in all three outcomes (in-hospital death, length of stay, and cost). Medium-volume surgeons achieved results equivalent to high-volume surgeons when they operated in high- or medium-volume hospitals.

CONCLUSIONS

A skewed distribution of case volumes by surgeon was found in this study of patients who underwent resection for large bowel cancer in Maryland. The majority of these surgeons performed very few operations for colorectal cancer per year, whereas a minority performed >10 cases per year. Medium-volume surgeons achieved excellent outcomes similar to high-volume surgeons when operating in medium-volume or high-volume hospitals, but not in low-volume hospitals. The results of low-volume surgeons improved with increasing hospital volume but never equaled those of the high-volume surgeons.

Endovascular graft repair of ruptured aortoiliac aneurysms

BACKGROUND

The feasibility of endovascular graft (EVG) repair of ruptured aortoiliac aneurysms (AIAs) has yet to be demonstrated. There are inherent limitations in EVG repair, including the need for preoperative measurements of the aneurysmal and adjacent arterial anatomy to determine the appropriate size and type of graft and the inherent delay to obtain proximal occlusion. We developed an EVG system with broad versatility that largely eliminates these problems.

STUDY DESIGN

Between 1993 and 1998, within an experience of 134 endovascular AIA repairs, 12 ruptured AIAs were treated using EVGs that facilitated intraoperative customization and eliminated the need for preoperative measurements. The EVGs consisted of either a Palmaz stent and a PTFE graft deployed by a compliant balloon (n = 9) or a self-expanding covered stent graft (n = 3). Both grafts were cut to the appropriate length intraoperatively. The mean age of the patients was 72 years (range 40 to 86 years). The mean size of the aneurysms was 7.6 cm (range 3 to 16 cm). Preoperative symptoms were present in all patients and included abdominal or back pain (n = 9), syncope (n = 4), and external bleeding (n = 2). All patients were high surgical risks because of comorbid disease (n = 10) or previous abdominal operations (n = 6), and nine experienced hypotension.

RESULTS

All EVGs were inserted successfully and excluded the aneurysms from the circulation. The mean operating time was 263 minutes, the mean blood loss was 715 mL, and the mean length of hospital stay was 6.5 days. There were two deaths (16%), one from the preexisting acute myocardial infarction and one from multiple organ failure. There were three minor complications (25%). Two patients required evacuation of an intraabdominal hematoma from the initial rupture. All but one of the grafts was functioning at a mean followup of 18 months.

CONCLUSIONS

This study demonstrates the feasibility of EVG repair for ruptured AIAs using a graft that can be customized intraoperatively for each patient. Such repairs currently are valuable in patients with ruptured AIAs and serious comorbidities and may be applicable in other circumstances as well.