Laparoscopic Surgical Manipulations Affect the Mechanical Properties and the Microstructure of Polymeric Sutures

Abstract

In the last years a new clinical method to carry out surgical operations has been introduced. It consists in minimally invasive vascular surgery (also called laparoscopy). In one hand, during laparoscopy procedures, sutures cannot be handled with fingers, and the use of stainless-steel needle holders is required. In the other hand, companies that fabricate sutures clearly mention that metal-made devices should be avoided when manipulating the monofilaments. Therefore, the manipulation of the suture monofilaments (made of polymers) by laparoscopic needle holders (made of metals) is controversial. Literature in this field is limited and incomplete. Therefore, the aim of this study was to investigate the mechanical and microstructural effects of the manipulations with laparoscopic needle holder on polymeric suture monofilament. Surgipro© (polypropylene), Teflene© (polyvinylidene fluoride) and Gore-Tex© (polytetrafluoroethylene) monofilament suture were pinched with a standard clinical protocol by a surgeon. Scanning electron microscopy, micro-mechanical testing, differential scanning calorimetry, x-ray diffraction, small angle x-ray scattering and Fourier transform infrared spectroscopy were then performed. Results showed that the ultimate tensile strength of Teflene and Gore-Tex sutures does not change after pinching whereas it decreases significantly for Surgipro sutures. This is attributed to stress concentration and to the compressive strength applied on the monofilament, which are closely related to the permanent deformation of the suture after pinching. Teflene and Gore-Tex monofilament sutures showed to be not affected even after severe pinching with laparoscopic needle holders. Therefore, our results clearly showed that the use of Surgipro II sutures in laparoscopic interventions should be avoided.