Ruptured abdominal aortic aneurysms: Clinical presentation in Auckland 1993-1997

Background: Rupture of an abdominal aortic aneurysm (RAAA) carries a report ed mortality rate in the range of 32-95%. Survival requires prompt diagnosi s and surgical management. The presenting features, however, are varied, of ten insidious and potentially misleading with Osler noting nearly 100 years ago that a correct premortem diagnosis was achieved in only 33% of cases. The present study aims to review our present accuracy in diagnosing this co ndition and outline demographic and presenting features of patients with RA AA. Methods: A review was undertaken of hospital and Coroner's files of all pat ients residing in the Auckland Coronial region who had RAAA between 1 Janua ry 1993 and 31 December 1997. Results: Three hundred and twenty-nine cases of RAAA were identified, and t hey occurred most commonly in the 8th decade. The male:female ratio was 3:1 and at least 73% of patients were Caucasian. The overall mortality was 71% . Nearly half underwent surgery and the hospital averaged mortality rate wa s 46%. No patient survived without surgery. Classic presenting features of RAAA were absent in many cases. Abdominal pain, back pain and a palpable ma ss occurred in only 49%, 36% and 18% of patients, respectively. Other commo n presenting symptoms included vomiting, general malaise and pelvic or hip pain. Forty-three patients (16%) were initially misdiagnosed. Conclusions: Although our ability to correctly diagnose a RAAA has improved since Osler's time, the initial misdiagnosis rate of 16% leaves no room fo r complacency. Ruptured abdominal aortic aneurysms must be included in the differential diagnosis of any patient over the age of 55 years who presents with shock, even if the pain is non-specific or atypical.