Polyethylene Terephthalate

How is Polyethylene terephthalate used clinically?

Mechanical and biological properties of four materials classically used in surgery /were compared/: polyethylene terephthalate (Mersilene), polypropylene (Marlex), polytetrafluoroethylene (Teflon) and expanded one (Gore-Tex) and polyaramide (Kevlar). No deterioration for polytetrafluoroethylene and polypropylene under irradiation was observed when materials were treated by physical means. Mechanical tests showed that all these materials could bear more than 50 N. Such a high tensile strength is never reached in visceral physiology. Results of graft elongation during tensile strength test shows two classes: a first one that includes high elongation grafts (Gore-Tex and Marlex) and a second one that includes low elongation grafts (Mersilene and Kevlar). As these materials have many potential uses in surgery, we have performed cytotoxicity tests. Material extracts were obtained under standardized conditions, and we have looked at a potentially toxic effect of substances eventually leached from the materials towards cells cultured in vitro. None of the material extracts listed above were cytotoxic except for untreated Kevlar. Toxicity disappeared when Kevlar was treated with methanol... Polyester (Mersilene) sutures ...Astigmatic results and complications of the combined suturing technique in penetrating keratoplasty by using 11-0 Mersilene as a running suture /were evaluated/. Twenty-seven grafts were studied for a follow-up that ranged between ten and 46 months (mean, 27.2 months). During the study, complications included three graft failures, one instance of inadvertent breakage of the running suture, one instance of one suture bite cutting through the recipient cornea, and suture microabscesses in two eyes. Keratometric astigmatism was 2.5 +/- 2.1 diopters at six months, was 2.4 +/- 2.3 diopters at 12 months, and was 2.5 +/- 2.0 diopters at 24 months. The data indicate that 11-0 Mersilene is suitable for the running suture in corneal transplants in the combined t