M P Fitzgerald1, J Mollenhauer, L Brubaker. 1. Division of Urogynecology and Reconstructive Pelvic Surgery, Rush-Presbyterian-St-Luke's Medical Center, Chicago, IL, USA. mfitz8@luc.edu
Abstract
OBJECTIVE: To explore the in vivo characteristics of donor fascia used in urogynaecological procedures, in a canine model. MATERIALS AND METHODS: Two experiments were conducted. In the first, donor fascia grafts were obtained from 12 dogs, the grafts freeze-dried and half were irradiated. The grafts were used for sacrocolpopexy and suburethral slings in each of five dogs. The dogs were killed at 2, 6 and 12 weeks after graft implantation, the grafts retrieved and assessed using tensilometry. In the second experiment, unirradiated sacrocolpopexy grafts were implanted in eight dogs; four grafts were placed under no tension and four under moderate tension. At 8 weeks, the grafts were retrieved and assessed by tensilometry. Measures of strength in both experiments included the ultimate tensile strength, ultimate strain and stiffness. All measures were compared using Kruskal-Wallis nonparametric tests in both studies. RESULTS: In the first experiment, a significant minority (23%) of grafts had complete loss of strength. Measures of graft strength did not vary when analysed according to donor dog, host dog, history of graft irradiation, duration of implantation or location of graft. In the second experiment, grafts placed under no tension tended to have lower tensile strength (chi2(1) = 3.125, P = 0.077), lower stiffness (chi2(1) = 3.125, P = 0.077) and lower ultimate strain (chi 2(1) = 3.182, P = 0.074). CONCLUSION: Graft irradiation as an isolated variable did not predispose grafts to failure in vivo. Biomechanical factors at the implantation site are likely to play a critical role in determining ultimate graft strength.
OBJECTIVE: To explore the in vivo characteristics of donor fascia used in urogynaecological procedures, in a canine model. MATERIALS AND METHODS: Two experiments were conducted. In the first, donor fascia grafts were obtained from 12 dogs, the grafts freeze-dried and half were irradiated. The grafts were used for sacrocolpopexy and suburethral slings in each of five dogs. The dogs were killed at 2, 6 and 12 weeks after graft implantation, the grafts retrieved and assessed using tensilometry. In the second experiment, unirradiated sacrocolpopexy grafts were implanted in eight dogs; four grafts were placed under no tension and four under moderate tension. At 8 weeks, the grafts were retrieved and assessed by tensilometry. Measures of strength in both experiments included the ultimate tensile strength, ultimate strain and stiffness. All measures were compared using Kruskal-Wallis nonparametric tests in both studies. RESULTS: In the first experiment, a significant minority (23%) of grafts had complete loss of strength. Measures of graft strength did not vary when analysed according to donordog, host dog, history of graft irradiation, duration of implantation or location of graft. In the second experiment, grafts placed under no tension tended to have lower tensile strength (chi2(1) = 3.125, P = 0.077), lower stiffness (chi2(1) = 3.125, P = 0.077) and lower ultimate strain (chi 2(1) = 3.182, P = 0.074). CONCLUSION: Graft irradiation as an isolated variable did not predispose grafts to failure in vivo. Biomechanical factors at the implantation site are likely to play a critical role in determining ultimate graft strength.
Authors: Andrew J Walter; Abraham N Morse; Kevin O Leslie; Joseph G Hentz; Jeffrey L Cornella Journal: Int Urogynecol J Pelvic Floor Dysfunct Date: 2005-06-23