Acute limb ischemia associated with type B aortic dissection: clinical relevance and therapy.

BACKGROUND: The goal of the current study is to characterize the presentation, therapy, and outcomes of acute limb ischemia (ALI) associated with type B aortic dissection (AoD).

METHODS: The prospective/retrospective International Registry for Acute Aortic Dissection (IRAD) database and a single institutional database were queried for all patients with type B AoD from 1996 to 2002. Univariate and multivariate statistics were used to delineate factors associated with morbidity and mortality outcomes.

RESULTS: According to the IRAD data (n = 458), the mean age of patients was 64 years, and 70% were men. The overall mortality was 12%; of these, 6% had ALI. Pulse (3-fold) and neurologic deficits (5-fold) were more common in those with ALI (P < .001). Endovascular, but not surgical therapy, was more commonly performed in patients with ALI compared with those without ALI (31% vs 10%, P = .004). No difference in age, race, gender, or origin of dissection was observed. ALI was associated with acute renal failure (odds ratio [OR] = 2.7; 95% confidence interval [CI] 1.1-7.1; P = .048) and acute mesenteric ischemia/infarction (OR = 6.9; 95% CI 2.5-20; P < .001). Adjusting for patient characteristics, ALI was associated with death (3.5; 95% CI 1.1-10; P = .02). The single institution analysis revealed similar patient demographics and mortality in 93 AoD patients, of whom 28 had ALI. Aortic fenestration or aorto-iliac stenting was the primary therapy in 93%; surgical bypass was used in 7%. Limb salvage was 93% in those with ALI at a mean of 18 months follow-up. The number of organ systems with malperfusion was 2-fold higher at aortography than suspected preprocedure (P = .002). By stepwise regression modeling, mortality was greater in those not taking a beta-blocker (OR = 19; 95% CI 3.1-111; P = .001).

CONCLUSIONS: ALI secondary to AoD is predictive of death and visceral ischemia. Endovascular therapy confers excellent limb salvage and allows diagnosis of unsuspected visceral ischemia.