The Need for a “Swan Neck” Permanentl Y Bent, Arcuate Peritoneal Dialysis Catheter

Abstract

In 1968 to ensure optimal function of a permanent catheter during periodic peritoneal dialysis, Tenckhoff recommended that a double-cuff catheter be inserted so that a slightly arcuate subcutaneous course would give the external and intraperitoneal segment a caudal direction. During the rapid growth of CAPD over the past five years, nephrologists generally have adapted the Tenckhoff's methods of catheter insertion but have encountered numerous complications. This paper describes a retrospective analysis of the complications associated with 83 peritoneal dialysis catheters functioned for 48,325 catheter days (132 catheter years) in 63 patients on continuous ambulatory peritoneal dialysis (CAPD) at our institution. Pericatheter leaks were seen only with midline insertions. Exit-site infections were significantly more resistant to treatment with singlecuff than with double-cuff catheters as assessed by the proportion of time that the exit-site is infected. If the subcutaneous tunnels were directed downward the infections were more responsive to treatment. Significantly more frequent catheter-tip migrations were observed with subcutaneous tunnel directed left and downward. Thus, our study supports Tenckhoff's observation that we can expect the lowest complication rate with double-cuff catheters with an arcuate tunnel, convex upwards. However, frequently this shape of tunnel is associated with external-cuff extrusions due to resilience of the straight catheter. To reconcile these conflicting requirements we recommend a new catheter permanently bent between the cuffs to eliminate one of the forces responsible for cuff extrusion. Such a catheter, named the swan-neck tunnel peritoneal dialysis catheter, should be inserted surgically through the belly of the rectus muscle.