Biocompatibility and biomechanical analysis of elastic TPU threads as new suture material.

High suture tension is one of the causes for many wound-healing problems. Constriction of tissue within the suture loops of nonelastic sutures can lead to cutting of the suture through tissues and necrosis of the tissue within these loops. The use of elastic materials in new suture types could give the material the ability to adapt tension to the tissue requirements and subsequently lead to more vital tissue within its loops. We evaluated the foreign body host response, as indicator of biocompatibility, to a new thermoplastic poly(carbonate) urethane (TPU) synthetic suture material in a rat model compared with standard nonelastic polypropylene (PP) sutures. Tissue samples were collected at 7 and 21 days, and host response was evaluated. Subsequently, suture tension curves of the new elastic sutures for the first 30 min after knotting were recorded in a pig model. The new TPU sutures showed an improved foreign body response when compared with that of PP, with a reduction in the amount of macrophages surrounding the material. Tension experiments showed a superior tension curve for TPU sutures, with a major reduction in peak suture tension when compared with that of standard PP sutures, while still retaining adequate tension after 30 min.