Mechanical properties of urogynecologic implant materials

Abstract

Synthetic suburethral slings have recently become popular despite the risk of erosion commonly associated with synthetic implants. Some of these materials seem to have unexpectedly low erosion rates. Based on the hypothesis that erosion is due, in part, to biomechanical properties, we undertook an in vitro study. The biomechanical properties of eight non-resorbable synthetic implant materials, stiffness (slope, N/mm) and peak load (N) were determined from load vs. displacement curves. Open-weave Prolene mesh showed unique biomechanical properties compared to other tested materials. The tension- free vaginal tape had the lowest initial stiffness (0.23 N/mm), i.e. low resistance to deformation at forces below the elastic limit, whereas the stiffest implant tested, a nylon tape, reached 6.83 N/mm. We concluded that the TVT and other wide-weave Prolene tapes have unique biomechanical characteristics. These properties may be at least partly responsible for the apparent clinical success of the implants.

Biomechanical properties of raw meshes used in pelvic floor reconstruction

“…These variations may be due to differences in weave and mesh architecture, polymer size and pore size. In our study, mesh samples exhibited consistent intra-group results, in contrast to the findings of Dietz et al [4] where some samples within each mesh group displayed moderate variance in stiffness and peak load. While there may be some variation in manufacturing, synthetic materials are more likely to be more uniform in quality than biological materials.…”

“…Various types of meshes are commercially available, and the risks and benefits have been previously documented [3]. Mechanical properties to failure of some meshes have been reported [4] and uniaxial tensile and flexural stiffness properties also assessed [5]. Cosson et al [6] reviewed mechanical properties of available synthetic implants and demonstrated that no perfect product currently exists.…”

Short-term outcome after transvaginal mesh repair of pelvic organ prolapse

“…Because of its beneficial profile in experimental settings [10,11], favorable pilot studies [12,13], as well as proven efficacy and tissue-friendly qualities when used in stress urinary incontinence surgery [14], most synthetic biomaterials currently marketed are monofilament, macroporous polypropylene mesh. This is the first report from an ongoing international, multicenter cohort study focusing on short-term outcomes of pelvic organ prolapse repair using a standardized surgical kit with macroporous, monofilament polypropylene mesh placed through a transobturator or transgluteal approach (Prolift®, Ethicon, Somerville, NJ, USA).…”

A safety and quality of life analysis of intravaginal slingplasty in female stress incontinence: a prospective, open label, multicenter, and observational study

“…In comparison with monofilaments, multifilaments are more flexible and less extensible, and thus, it is easier to adjust once positioned under the urethra with a lower incidence of postoperative voiding difficulties or retention [4]. However, the monofilament tape such as TVT procedure has the lower initial stiffness and elastic limit [16]; so, it is possible that even under minor tension, the tendency to retain its shape increases the risk of urethral constriction. Furthermore, TVT procedure requires an additional procedure of peeling the plastic sheath during surgery, which stretches the tape, and thus, the possibility of inducing voiding difficulties becomes high.…”