A new porous surface modification technology for peritoneal dialysis catheters as an exit-site cuff to reduce exit-site infections.

Catheter exit-site infection continues to be a more common morbid event in patients undergoing peritoneal dialysis. Previous attempts to place a biointegration material at the next site have failed to reduce infection rates. This study reports the use of an innovative microporous silicone material placed as a cuff around the catheter at the exit site. The porous material has a pore-sized distribution that stimulates and facilitates capillary ingrowth into the pores. This capillary ingrowth prevents scar tissue formation, increases blood supply, and theoretically improves the immunological competence of the tissue at the vulnerable exit site. Twenty-five test catheters (12 using standard exit-site creation and 13 using the Moncrief-Popovich implantation technique) were implanted in a canine model. The exit-site infection rate in a canine model without the microporous material was 100% at 2 months. The corresponding results with the microporous material was 40% at 2 months. The majority of the test catheters showed progressive drying and healing at the exit site. Sixty percent of the catheters healed quickly and remained infection-free. Biointegration of the microporous material at the exit-site was demonstrated. Several exit site infections with the test catheters treated only with local therapy (without systemic or topical antibiotics) demonstrated progressive healing and secondary adequate biointegration. Because of these encouraging results, human studies were initiated, with the first human implant occurring in August, 1994. A 10-patient project is planned for the next year.