Clinical characteristics of “tunnel infection” in continuous ambulatory peritoneal dialysis (CAPD)

We analyzed CAPD-related tunnel infections (TI) that occurred during a recent 5-year period in our dialysis center. Forty-two patients (24-65 years old, 15 females and 27 males, 37 non-diabetics and 5 diabetics) were started on CAPD between January 1987 and December 1990, and continued until December 1991. A double-cuffed Tenckhoff catheter (swan neck type) was implanted in all patients. Fifty-three episodes of TI occurred during the total observation period of 1559 paatient-months (0.41 times/year), and the affected period of these episodes was 323 patient-months (21% of the total observation period). Forty-five episodes in which the outcome was determined by December 1991 were analyzed. The results were as follows: (1) Twenty-one episodes (47%) required surgical treatment (“unroofing” or catheter removal). Sixty-seven percert of TI coused by Staphylococcus aureus and 100% caused by Pseudomonas aeruginosa required surgical treatment. (2) The mean affected period of TI was 6.4 months. Seventy-six percert of the prolonged cases (over 6 months) required surgical treatment, whereas only 29% of cases under 6 mosths required this. (3) We defined advanced TI on the basis of local features such as necrotic tissue, overt abscess, fistula, cuff extrusion, or tissue deficit due to necrosis. Twenty-four episodes (53%) were advanced TI, and 88% of these required surgical treatment. Our results indicate that TI episodes caused by S. aureus or P. aeruginosa, prolonged TI episodes of over 6 months, and advanced TI, should all be treated surgically as early as possible.