Implantable insulin pumps: infections most likely due to seeding from skin flora determine severe outcomes of pump-pocket seromas.

Abstract

Complications at implantation site of implantable insulin pumps may lead to premature removal. To elucidate the origins and the outcomes of these local adverse events. We investigated seromas of the 'pump-pocket' that have been detected for an eight month-period during the follow-up of such-treated forty type 1 diabetic patients. At the start of study period, skin bacterial flora was sampled at umbilicus and groin, and isolated strains of Staphylococcus epidermidis were preserved in specific vials at -20 degrees C. Each time a seroma was detected at transcutaneous 45 days-refill of pump reservoir, it was sampled for bacterial cultures. Isolated strains of S. epidermidis from seroma were genetically compared to preserved strains of corresponding patients using Pulsed-Field Gel Electrophoresis (PFGE) after genomic restriction by SmaI. Among the ten seromas that occurred after a mean time of 9.9 months since implantation, S. epidermidis were isolated in five cases. Genetic comparison of isolated strains could be performed in three cases. Compared strains showed identical (in 2 cases) or closely related (in one case) PFGE profiles. While the five aseptic seromas resolved with rest, four infected cases required explantations after one to nineteen months in spite of antibiotic therapy and the fifth one persisted without impairment under long-term antibiotics. Our results suggest that seeding from the skin flora is a key-factor determining the severity of pump-pocket complications. We recommend that bacterial investigations of pump-pocket seromas should be systematically performed, while prophylactic measures might include antibiotic cover for each puncture of the pump-pocket.