A randomized controlled trial of coiled versus straight swan-neck Tenckhoff catheters in peritoneal dialysis patients

Background. Current clinical practice guidelines recommend that no particular type of peritoneal dialysis (PD) catheter has been proved superior to another. However, a recent Cochrane review recommended the need for a large, well-designed, randomized, controlled trial of straight versus coiled PD catheters because of the paucity and suboptimal quality of previously performed trials. Methods: A randomized controlled trial was undertaken at 2 metropolitan teaching hospitals comparing the effects of straight versus coiled PD catheters on time to catheter malposition (primary outcome), catheter-associated infection, technique failure, and all-cause mortality. Results One hundred thirty-two PD patients were enrolled and randomly assigned to insertion of a coiled (n = 62) or straight catheter (n = 70). There was no significant difference in time to laparoscopic reposition between the 2 cohorts (log-rank score, 0.41; P = 0.52). However, median technique survival was significantly worse for coiled catheters (1.5 years; 95% confidence interval [CI], 1.2 to 1.8) compared with straight catheters (2.1 years; 95% CI, 1.8 to 2.5; P < 0.05), primarily because of increased risk for inadequate dialytic clearance with the former. On univariate Cox proportional hazards model analysis, insertion of a coiled PD catheter was associated significantly with a greater risk for technique failure (unadjusted hazard ratio, 1.86; 95% CI, 1.03 to 3.36). No difference was observed between the 2 groups with respect to catheter-associated infections or overall patient survival. Conclusion: Coiled catheters do not influence the risk for drainage failure caused by catheter malposition compared with straight catheters, but are associated with significantly increased risk for PD technique failure, primarily because of inadequate dialytic clearance.