Lapra-Ty Holding Strength and Slippage with Various Suture Types and Sizes

Abstract

To investigate the holding strength and slippage of Lapra-Ty clips on various suture types and sizes. Using an automated materials testing system with the Lapra-Ty in a fixed position, Lapra-Ty holding strength and displacement were determined with 0, 2-0, 3-0, and 4-0 Vicryl, Monocryl, and polydioxanone suture (PDS). To simulate clinical application, Lapra-Tys were also tested by applying a load to these sutures after being passed through a full-thickness layer of tautly suspended fresh porcine bladder tissue. Three trials were performed with each suture type and size. The Lapra-Ty holding strength with Vicryl suture was significantly higher than with Monocryl or PDS of the same suture size in bladder tissue trials. Monocryl suture had a significantly higher displacement than Vicryl or PDS of the same suture size in bladder tissue trials (except for 4-0 Monocryl and PDS having insignificantly different displacements). Lapra-Tys slipped off Vicryl, Monocryl, and PDS in 25%, 67%, and 67% of their respective trials. Lapra-Tys did not slip during any of the trials with 2-0 suture of any type or 3-0 Vicryl. Lapra-Tys with holding strengths on suture less than approximately 8 Newtons (N) slipped and greater than 8 N pulled through the bladder tissue without slipping. The optimal suture type and size to maximize Lapra-Ty holding strength and minimize slippage was determined to be 2-0 and 3-0 Vicryl, 2-0 Monocryl, and 2-0 PDS. Monocryl suture stretches more than Vicryl and PDS at higher loads.