Abdominal aortic aneurysms. A comparative analysis of surgical treatment of symptomatic and asymptomatic patients

Elective surgery for aortic abdominal aneurysm: comparison of English outcomes with those elsewhere

INTRODUCTION

The aim of this study was to quantify mortality after elective repair of abdominal aortic aneurysm (AAA) in England, and to compare English case fatality rates (CFRs) with those reported in the literature.

PATIENTS AND METHODS

English Hospital Episode Statistics (HES) for the financial years 1998/9 to 2001/2, linked to death data, were analysed. A systematic literature search was undertaken to identify studies reporting CFRs after elective AAA surgery. The CFR in England was compared with these studies by using confidence intervals on the CFRs and funnel plot techniques.

RESULTS

In the English study, elective repair of AAA was performed on 11,338 patients of whom 771 died within 30 days after surgery (6.8%). The literature search found 66 studies: 34 reported mortality rates that were within the 99% confidence limits of the English rates, 31 below, and one study above.

DISCUSSION

The CFR after elective surgical repair in England within 30 days of operation (6.8%) was higher than expected from the literature. Differences between England and other countries in quality of care is one possible explanation for the findings, but other explanations are possible and are discussed.

Emergency operation in patients with symptomatic abdominal aortic aneurysms

To assess the need for routine preoperative computerized tomography scanning to discern patients with rupture among those presenting with acutely symptomatic abdominal aortic aneurysms, a retrospective review was performed. During a 5-year period, all patients presenting with symptomatic aneurysm underwent emergency operation without preoperative computerized tomography. The mortality rate was not significantly different among patients with symptomatic, intact aneurysms undergoing emergency operation (3 percent) and those without symptoms having elective operation (5 percent). The mortality rate of patients with ruptured aneurysms was 68 percent. We concluded that the addition of preoperative computerized tomography to the clinical evaluation would not have improved these results. Furthermore, since it is expensive and delays emergency operation in patients with ruptured aneurysms, computerized tomography seems rarely indicated in symptomatic patients with obvious aneurysms.

[Morbidity and mortality following resection of an aortic aneurysm in the aged]

From August 1984-August 1985 118 abdominal aortic aneurysms were treated surgically in the City Hospital Nuremberg. The mean age was 68.9 years, with 26.3% being over 75 y.; and there was a notable decline of elective procedures in this group, which was particularly jeopardized by cardial arrhythmias and renal insufficiency. The lethality was 0 in elective procedures, but reached 50% for symptomatic and over 50% for perforated aneurysms in the old age group. The high lethality of ruptured aortic aneurysms justify elective operation of aortic aneurysms in high age.

[Sonographic observation of the course of aneurysms of the abdominal aorta]

Forty-two patients with an abdominal aortic aneurysm that had not been treated surgically were repeatedly examined by ultrasonography. The average observation time of all patients was 3.1 years. The total observation period including follow-up times of all patients adds up to 129 "patient years". Within this time none of the 35 asymptomatic abdominal aneurysms with transversal diameters of maximally 5 cm ruptured. Three patients of seven with larger and symptomatic aneurysms died in consequence of a rupture. Small asymptomatic abdominal aortic aneurysms seem to have a better prognosis than previously supposed. The question whether all abdominal aneurysms should be operated on needs reconsideration, especially in the elderly.