Percutaneous Management of Complications (Aortoenteric Fistula and Sac Abscess) Following Bypass Surgery for Abdominal Aortic Aneurysm

Abstract

A 45-year-old man initially presented with pulsatile abdominal swelling and uncontrolled hypertension of 3 months’ duration. He was diagnosed to have atherosclerotic abdominal aortic aneurysm, for which he underwent proximal and distal ligation of the aneurysmal aorta and aortoaortic bypass graft of the descending thoracic aorta to the infrarenal abdominal aorta with a right iliorenal bypass graft. One year after this surgery, he developed hematemesis, malena, and severe backache. Angiography revealed persistent filling of the ligated native aortic aneurymal lumen through the active leak at the proximal bypass graft anastomosis with the descending thoracic aorta (Figs.1a and 1b). A Zenith custom-made aortic stent graft (Cook Inc., Australia) was placed across the anastomosis to treat the leak (Fig. 1c). Antibiotic prohylaxis was given for a week in view of arteriotomy. The patient was asymptomatic for 1 year after the aortic stent graft placement, and subsequent follow-up imaging (CT scan) was unremarkable (Fig. 2a). Six months later, i.e., 18 months after placement of the stent graft, he developed pyrexia of unknown origin, with chills and rigors, that was not responsive to antipyretics. All the routine investigations for pyrexia of unknown origin were unremarkable. However, CT scan showed a high-density fluid collection, with an air fluid level in the native aortic aneurysmal lumen suggesting an abscess in the native aneurysmal sac (Fig. 2b). A 10-Fr pigtail drainage catheter was inserted into the abscess cavity under CT guidance (Figs. 3a and b). It drained frank greenish pus, microscopic examination of which showed enterococci. Daily intracavitary antibiotic flushes of chloramphenicol and gentamycin were given through the drainage catheter for 3 weeks, along with parenteral antibiotics. The fever subsided and the drain output decreased gradually. Repeat CT scan, once the drain output was nil and the patient had become asymptomatic, showed a collapsed native aortic aneurysmal cavity with no residual pus (Fig. 3b). The patient remained symptom-free at 1-year clinical and imaging follow-up.