Tensile strength of cadaveric fascia lata compared to small intestinal submucosa using suture pull through analysis

Purpose: The modified pubovaginal sling has become popular as first line tr eatment for stress urinary incontinence. With the increasing use of cadaver ic fascia as a sling material, widespread shortages are prevalent, hence li miting its availability. The increased morbidity with the use of synthetic sling materials and autologous fascia has stimulated investigation of other sling materials. We evaluated the tensile strength of 4 suture types, and compared tensile strength of cadaveric fascia lata to porcine small intesti nal submucosa using suture pull through analysis to assess their efficacy a nd durability for use in anti-incontinence procedures. Materials and Methods: Suture breaking load was determined using 2 and 1-ze ro polypropylene suture, and 2 and 1-zero polyglactin suture. Freeze dried gamma irradiated human fascia lata and freeze-dried small intestinal submuc osa were evaluated. Suture was fixed to sling material using the cross fold technique. Mean suture breakage and suture pull through were determined us ing a tensionometer by measuring the load applied to the sling/suture syste m. Statistical analysis was performed. Results: Mean suture breakage load was greatest with 1-zero polyglactin (8. 10 pounds) and least with 2-zero polypropylene (3.68 pounds). Mean suture b reakage strength was similar for 1-zero polypropylene and 2-zero polyglacti n at 5.26 and 5.40 pounds, respectively. Mean suture pull through load usin g 1-zero polypropylene suture and the cross fold technique was 5.64 pounds for cadaveric fascia and 2.74 pounds for small intestinal submucosa (p <0.0 001). Maximum load was limited by the suture strength when using cadaveric fascia, whereas, maximum load was limited in small intestinal submucosa by its inherent tensile strength. However, using a new technique for suture fi xation to the small intestinal submucosa, we were able to increase signific antly mean suture pull through load to 3.36 pounds (p = 0.008). Additionall y, with this new technique small intestinal submucosa allowed gross stretch ing before suture pull through that was not seen with cadaveric fascia. Conclusions: Despite the current standard use of 1-zero polypropylene sutur e for pubovaginal sling fixation, our data suggest that 1-zero polyglactin suture is the strongest, and its use with pubovaginal sling fixation warran ts further investigation. Using the cross fold technique and 1-zero polypro pylene suture, tensile strength was greatest with cadaveric fascia compared to small intestinal submucosa. Although small intestinal submucosa was not as strong as cadaveric fascia, our persuasive preliminary data suggest tha t further investigation is warranted in the use of small intestinal submuco sa and other suture fixation techniques, and its observed stretch capacity. Hence, with further studies small intestinal submucosa may remain a viable option for pubovaginal sling material.