Catheter-related infections remain a significant cause of method failure in chronic
peritoneal dialysis (PD)
therapy. Given the increasing antibiotic resistance, such nonpharmacological strategies as local
silver devices attract more interest. To establish whether a
silver ring device (designed by Grosse-Siestrup in 1992) mounted onto the PD
catheter and placed at the exit site at skin level is effective in preventing exit-site and other
catheter-related infections, a prospective 12-month, multicenter, controlled study stratified by diabetes status was conducted. The study subjects were assessed by an extensive structured inventory, including a broad spectrum of control variables, such as age, body mass index (BMI), Staphylococcus aureus carrier status,
catheter features, mode and quality of PD
therapy, comorbidity, and psychosocial rehabilitation. Ten experienced German outpatient dialysis centers (seven adult, three pediatric) participated in the trial. All eligible patients (n=195) from the study area without
catheter-related infections during the ascertainment period were included (incidental subjects undergoing PD
therapy for at least 3 months). The main outcome measures were the occurrence of first exit-site
infections (primary study end point), sinus tract/tunnel
infection, and
peritonitis. Ninety-seven patients were assigned to the
silver ring and 98 patients to the control group. Baseline characteristics of age, sex, proportion of pediatric and incidental patients, S aureus carrier status, and other variables were similar in both groups. The incidence of
infections in the
silver ring group versus the control group was as follows: 23 of 97 versus 16 of 98 patients had exit-site
infections, 12 of 97 versus 12 of 98 patients had sinus tract/tunnel
infections, 16 of 97 versus 18 of 98 patients had
peritonitis, respectively. Kaplan-Meier analysis for the probability of an
infection-free interval showed no statistical difference (log-rank test) between the two groups. Displacement of the
silver ring contributed to study termination in 6% of the study group patients, including two patients with
catheter loss. Univariate analysis and multiple logistic regression identified younger age (<50 years), low
serum albumin level (<35 g/L), number of previously placed PD
catheters, short cuff-exit distance (<2 cm), and S aureus nasal carriage as risk factors for the development of exit-site
infections. In conclusion, our study does not show any benefit of the
silver ring in preventing
catheter-related infections in PD patients. Thus, prevention of
infection-related method failure in PD still has to rely on conventional
antibiotic treatment strategies and less so on alternative methods.