The purpose of this study was to evaluate the in vitro and in vivo efficacy of a new connection system for continuous ambulatory peritoneal dialysis (CAPD), called the T-set. With this system the patient wears a 27-cm extension line filled with Amuchina during the dwell time; the bag is made of a fill container linked to a drainage tube with a Y-shaped set. For bag exchange, only one connection is needed and this is subsequently flushed with the entire drainage volume. The in vitro efficacy of the system was tested with 20 sets filled with 10 mL of Amuchina and inoculated in the distal lumen with 2.1 x 10(3) colony-forming units (cfu) of S. aureus. After an incubation of 4-6 hours at 35-37 degrees C, three dialysate samples per set were collected, respectively, at the beginning of drainage and filling. All 120 samples were negative, whereas two control sets, filled with a phosphate-buffered saline, had positive drainage samples, and at least one positive infusion sample, indicating the efficacy of Amuchina in sterilizing the system under conditions simulating touch contamination. To evaluate the in vivo efficacy, safety, and acceptability of the T-system, a prospective randomized controlled trial was performed in seven centers: a control group (CG) of 56 patients (follow-up: 952.3 months, mean +/- SD: 17.0 +/- 7.8) was treated with a long branch (21 patients) or short branch (35 patients) Y-set and a test group (TG) of 66 patients (follow-up:898.1 months, mean +/- SD: 13.6 +/- 7.8) with the T-set.(ABSTRACT TRUNCATED AT 250 WORDS)