Extra-anatomic revascularization and aortic exclusion for mycotic aneurysms of the infrarenal aorta and iliac arteries in an Asian population

Abstract

Objectives: To study the clinical presentation, management and eventual outcome of patients with mycotic abdominal aortic aneurysms managed with aortic exclusion and extra-anatomic reconstruction.

Design: A retrospective chart review of 18 cases treated at a single institution.

Methods: Medical records of 18 patients admitted to our institution from October 1997 to July 2006 with a diagnosis of mycotic abdominal aortic aneurysms were reviewed. In all cases, the diagnosis was confirmed by abdominal computed tomography and empirical parenteral antibiotics were administered. Seventeen patients had surgical debridement, aneurysm exclusion, and extra-anatomic reconstruction. The antibiotics were continued in the postoperative period for 6 weeks.

Results: Immunosuppression was present in 72%, with diabetes mellitus present in 56%. Salmonella sp was the causative organism in 72% of cases. Most patients presented late, with a 67% incidence of contained rupture. Seventy-two percent needed early or emergency surgery with less than 1 week of preoperative antibiotics. Disease-specific mortality was 39% (7/18). There was 1 late death during the mean follow-up period of 34 +/- 26 months. One patient with an infrarenal aneurysm arising relatively close (neck, 2 cm) to the renal arteries died on table when proximal ligatures cut through the friable aortic wall, resulting in uncontrollable exsanguination. One third of patients on long-term graft surveillance developed mild to moderate stenosis at the anastomotic site.

Conclusions: Empirical antibiotics must be started early, aiming to achieve 1 week of antibiotics prior to surgery. In the Asian population, 3 characteristics are apparent: (1) most patients are immunocompromised; (2) patients present late in the course of disease; and (3) Salmonella is usually responsible. Extra-anatomic bypass may provide a safe option for revascularization of mycotic aneurysms of the iliac arteries and infrarenal aorta.