Papers by Keyword: Surgical Sutures

Abstract: The bulk ring-opening copolymerisation of L-lactide (LL) and ε-caprolactone (CL) with an initial comonomer feed ratio of LL:CL = 75:25 mol % was carried out using stannous acetate as the initiator at 120 oC for 48 hrs. The copolymer was characterised by GPC, DSC and TGA. Due to its ability to biodegrade in the human body, this type of copolymer has potential for use as an absorbable surgical suture. The copolymer obtained was melt spun at 153 oC using a small-scale melt-spinning apparatus and extruded into ice-cooled water to produce an as-spun monofilament fibre which was largely if not completely amorphous. Alternate off-line hot-drawing and annealing (3 cycles) was carried out in order to develop the fibre’s oriented semi-crystalline morphology. To complete the processing operation, thermal treatment was necessary to stabilize the fibre morphology. It was found that fixed annealing at 60 oC followed by free annealing at 60 oC stabilized the fibre morphology as a result of molecular relaxation. In vitro hydrolytic degradation studied in a phosphate buffer saline (PBS) solution of pH 7.4 at 37.0 ± 0.1 oC indicated that, after 6 weeks immersion in the buffer, the fibre’s tensile strength decreased by approximately 50% whereas a commercial ‘PDS’ suture of similar size lost its strength completely after only 4 weeks.

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.