A statewide, population-based time-series analysis of the outcome of ruptured abdominal aortic aneurysm

The purpose of this study was to perform the first statewide, population-based, time-series analysis of the frequency of ruptured abdominal aortic aneurysm (RAAA), to determine the outcomes of RAAA, and to assess the association of patient, physician, and hospital factors with survival after RAAA. The hypotheses of the study were as follows: 1) the rate of RAAA would increase over time and 2) patient, surgeon, and hospital factors would be associated with survival.

Ruptured abdominal aortic aneurysm is a life-threatening emergency that presents the surgeon with a technically demanding challenge that must be met and surmounted in a short time if the patient is to survive.

Data were obtained from the following four separate data sources: 1) the North Carolina Hospital Discharge database, 2) the North Carolina American Hospital Association database, 3) the North Carolina State Medical Examiner's database, and 4) the Area Resource File. All patients with the diagnosis of an abdominal aortic aneurysm (AAA) were selected for initial assessment. Patients were grouped into those with and those without rupture of the abdominal aneurysm.

During the 6 years of the study, 14,138 patients were admitted with a diagnosis of AAA. Of these, 1480 (10%) had an RAAA. The yearly number of patients with elective AAAs increased 33% from 1889 in 1988 to 2518 in 1993. The yearly number of RAAAs increased 27% from 203 to 258. The mortality rate for AAA was 5%, as compared with 54% in RAAA patients. The patient's age was found to be the most powerful predictor of survival. Univariate logistic regression analyses demonstrated an association of the surgeon's experience with RAAA and patient survival after RAAA. Analysis of the survival rates of board-certified and nonboard-certified surgeons demonstrated that patients with RAAAs who were treated by board-certified surgeons had significantly better survival. When the survival was compared in small (less than 100 beds) and large (more than 100 beds) hospitals, survival was significantly better in the larger hospitals.

Ruptured abdominal aortic aneurysm remains a highly lethal lesion, even in the best of hands. Despite the many improvements in the care of seriously ill patients, there was no significant improvement in the survival of RAAA during this study. This suggests that early diagnosis is the best hope of survival in these patients. The study demonstrated that survival after RAAA was related most strongly to patient age at the time of the RAAA. The physician's and the hospital's experience with RAAA, the physician's background as measured by board certification, and the type of hospital at which the operation was performed (small vs. large) also may be associated with survival. These findings may have important implications for the regionalization of care and the education and credentialling of physicians. Given the lack of recent progress of improving the outcome of RAAA, aggressive efforts to treat patients before rupture are appropriate.