silicon and Peritonitis

Zinc eluted from siliconized latex (SL) increases resistance of Pseudomonas aeruginosa to imipenem in vitro. A foreign body peritonitis model was used to evaluate the activity of imipenem using SL or silicone (S) implants. No differences were observed in mortality, positive blood cultures and tissue bacterial counts between SL and S implants. Implant-associated counts, however, were significantly higher in the SL group. It is concluded that SL decreases the activity of imipenem against P. aeruginosa.

Topics: Animals; Anti-Bacterial Agents; Bacterial Load; Catheters; Disease Models, Animal; Drug Antagonism; Female; Foreign Bodies; Imipenem; Latex; Liver; Mice; Mice, Inbred C57BL; Peritonitis; Pseudomonas aeruginosa; Pseudomonas Infections; Silicon; Spleen; Treatment Outcome; Zinc

We performed a prospective, double-blind, randomized study to evaluate whether stable surface heparinization of silicone peritoneal dialysis (PD) catheters prevents bacterial colonization or biofilm formation and improves healing of the exit site. Heparinized catheters were implanted in 20 Sprague-Dawley rats (group H) and non heparinized catheters in another 20 (group C). The PD catheters, constructed of silicon tubing with two polyester cuffs, were patterned after the standard Tenckhoff catheter. A covalent multipoint method of attachment onto polymeric surfaces was used for stable, permanent chemical immobilization of heparin on the PD catheter. Dialysis exchanges (25-mL instillation volume) were performed twice daily for 4 weeks through the permanent catheter. Prophylactic antibiotics were not used. The exit sites were evaluated at 2-week intervals. The extent of biofilm coverage on the intraperitoneal portion of the catheter (obtained at the end of the experiment) was assessed, and sonicated fluid from the catheter tip was cultured for evaluating bacterial colonization of the catheter. Exit-site scores in group H were lower than in group C (p = 0.052) at the end of week 4. Bacterial colonization tended to be less common in group H [2 of 12 catheters (17%)] than in group C [8 of 15 catheters (53%); p = 0.058], but the extent of biofilm, the peritonitis rate, and the inflammation score of tissue adjacent to the cuff were not different between the groups. Those data suggest that heparinized PD catheters can be a practical approach to the prevention of bacterial colonization and can improve healing of the exit site.

Topics: Animals; Anticoagulants; Biofilms; Catheters, Indwelling; Heparin; Male; Peritoneal Dialysis; Peritonitis; Rats; Rats, Sprague-Dawley; Silicon; Surgical Wound Infection

Continuous ambulatory peritoneal dialysis (CAPD) is associated with various problems, including damage to the CAPD catheter. We encountered catheter rupture around the titanium adaptor in a patient who had been on CAPD for 7 years. The area near the adaptor generally suffers damage secondary to deterioration of the silicon composing the catheter. However, stereoscopic and electron microscopic observation of the surface of the catheter revealed no deterioration. Instead, there were fine scratches around the site of rupture and the broken surface was rough. Since the patient did not protect the catheter with gauze near the titanium adaptor, it was probably damaged by the adaptor and then ruptured by some external force.

Topics: Anti-Bacterial Agents; Biomechanical Phenomena; Catheters, Indwelling; Humans; Injections, Intraperitoneal; Kidney Failure, Chronic; Male; Middle Aged; Peritoneal Dialysis, Continuous Ambulatory; Peritonitis; Silicon; Titanium