Aseptic periprosthetic fluid collection: a late complication of Dacron arterial bypass.

Fluid collection encompassing an arterial prosthesis often leads one to suspect graft infection. Four cases of aseptic seroma occurring three to five years after insertion of knitted Dacron implants for bypass are reported. The collection was serohematic in three cases, puriform in the other. Repeated bacteriological investigations did not reveal any growth and laboratory tests did not demonstrate any signs of infection. The following pathophysiologic hypotheses have been advanced: modification of the permeability of the prosthetic wall, immunoallergic reaction to the graft, and aging hematoma. The role played by anticoagulant is debatable. Management by needle aspiration or drainage failed. Multiple recurrences led to prosthetic replacement in three cases. Treatment consists of replacing the graft by one of a different fabric. These collections must be distinguished from postoperative lymphoceles, anastomotic false aneurysms, hematomas and infections.