Late Non-anastomotic Perforation of a Bifurcated Dacron Graft Caused by a Calcified Aneurysm Wall Remnant 11 Years After Open Abdominal Aortic Aneurysm Repair.

INTRODUCTION: Non-anastomotic rupture of a vascular prosthesis is an extremely rare complication in the late post-operative period. Modern gelatine coated woven Dacron grafts have demonstrated excellent long term durability and resistance to intrinsic degeneration. However, they remain susceptible to physical damage resulting from sustained mechanical irritation by surrounding hard tissues. A life threatening case of graft perforation caused by direct contact with a remnant calcified aortic wall 11 years after abdominal aortic aneurysm repair is reported.

REPORT: An 82 year old man, who had undergone bifurcated graft replacement (18 × 10 mm) (Gelsoft, Terumo Corporation, Tokyo, Japan) for abdominal aortic aneurysm 11 years earlier, presented to the emergency department with sudden abdominal pain and haemorrhagic shock. Contrast enhanced computed tomography revealed contrast extravasation into a new pseudo-aneurysm surrounding the right graft limb. Emergency exploratory laparotomy was performed. Intra-operative findings identified a pinhole perforation on the body of the right graft limb, distinct from the anastomotic sites. The perforation was in direct contact with a sharp, calcified lesion on the dorsal aspect of the remnant aneurysm wall that had been used for wrapping during the initial surgery. The defect was successfully repaired with direct sutures, and the surrounding sharp calcification was debrided. The patient was discharged on post-operative day 15 without complications.

DISCUSSION: The mechanism of injury was attributed to physical fraying of polyester fibres caused by repeated mechanical friction against the sharp calcified intima over a decade. Previous experimental studies support that pulsatile contact with hard tissues can physically disrupt woven Dacron fibres. Sharp calcified lesions should be removed, or cushioning material should be interposed between the graft and the aortic wall during the initial repair. This case highlights the need for long term morphological surveillance to assess the spatial relationship between the graft and calcified remnants, even in the very late post-operative phase.