Ruptured abdominal aortic aneurysm in a well-defined geographic area

Abstract

Objective: Despite an increasing number of elective operations on abdominal aortic aneurysms (AAAs), the age- and sex-standardized mortality rate of ruptured AAA (RAAA) continues to increase. In the Pirkanmaa region, population 440,000, all aortic surgery is performed at Tampere University Hospital (TAUH). Procedures have been collected into the vascular registry. The purpose of this study was (1) to establish the incidence, modes of treatment, and mortality of RAAA in a defined geographic area; (2) to evaluate the prerupture history to determine if there are any ways to prevent rupture; and to make a forecast about the increase of RAAAs in the next decades. Methods: Population and outcome data in the Pirkanmaa region and information on all patients who died of RAAA during 1990-1997 were provided by Statistics Finland. All operated RAAAs that underwent procedures during 1990 to 1999 were identified from the local vascular registry. To make a forecast for the next decades, an incidence of RAAA was calculated separately for each age group in 5-year intervals. Results: From 1990 to 1997, 221 patients presented with RAAA. The mean incidence was 6.3/100,000 inhabitants. The incidence in the population over 65 years was 35.5/100,000. The total RAAA mortality was 76.9%. A total of 139 patients reached TAUH and 111 underwent emergency surgery. The overall hospital mortality in TAUH was 63.3%. The calculated annual number of RAAA will increase 49.6% in the next 2 decades, and the overall incidence will increase from 6.3 to 8.9/100,000 inhabitants. According to the vascular registry, 166 patients were operated on for RAAA during 1990 to 1999 in TAUH. The 30-day mortality was 50.6%. A minority of the patients (n = 18, 10.8%) had a previously documented AAA. The median diameter at the time of rupture was 7 cm. Seven (5.0%) men and six (24.0%) women had a diameter of less than 5.5 cm. Conclusion: The incidence of RAAA in the Pirkanmaa region in 1990s was the Finnish average. In the next two decades, the number of individuals with RAAA will increase significantly. One quarter of women had a diameter of AAA at the time of rupture that was under the current threshold indicator for elective operation. (J Vasc Surg 2002;36:291-6.)