Acute Abdominal Aortic Dissection: Insight from the International Registry of Acute Aortic Dissection (IRAD)

Objectives: The aim of this study is to clarify the natural history of patients with isolated abdominal aortic dissections, identifing clinical characteristcs, therapeutic approches, risk factors for mortality, in-hospital outcome, and long-term results. Clinical differences with classic type B dissection are also examined.
Methods: Among 1417 patients enrolled in the International Registry of Acute Aortic Dissection (IRAD) from1996 to 2003, 18 (1.3%) had an isolated acute abdominal aortic dissection (IAAAD). A comprehensive analysis of 290 clinical variables was performed. IAAAD and type B dissections were compared using chi square and student's t test.
Results: Patients were medically, surgically or percutaneously managed in 12 (66.6%), 5 (27.8%) and 1 (5.6%) cases, respectively. The overall in-hospital mortality was 5.6% (1 patient). Compared to patients with type B aortic dissections, abdominal pain, mesenteric ischemia, limb ischemia and hypotension were significantly more frequent in patients with IAAAD. Mortality during follow-up (mean 5 years, range 1 month-9 years) occurred in 4 patients (33.3%). Overall survival at 1 and 5 years was 93% and 73%, respectively. All patients who died during the follow-up period had in-hospital medical management (p=0.04).
Conclusions: IAAAD is a condition that my present differently, compared to classic type B aortic dissections. IAAAD patients treated with surgical or endovascular procedures, resulted in a lower mortality, both in-hospital and long-term, when compared to those medically managed. On the basis of the present natural history report, continued surveillance appears mandatory. In order to improve the life expectancy of IAAAD patients, an aggressive management seems justified.