Tissue strength analysis of autologous and cadaveric allografts for the pubovaginal sling

The aim of this study was to compare the mechanical properties of autologous rectus fascia (ARF), two groups of commercially available cadaveric fascia lata commonly used in pubovaginal sling surgery [freeze- dried (FD) and solvent-dehydrated (SD)], and commercially available cadaveric dermal grafts (DG) evaluate differences in tissue strength and stiffness. We prospectively studied the maximum load to failure (MLF) and stiffness in 20 specimens of ARF, 20 specimens of FD, 20 specimens of SD, and 10 specimens of DG. Autologous fascia was obtained from patients undergoing pubovaginal sling operation utilizing rectus fascia. Cadaveric fascia war re-hydrated in saline. All specimens were then tailored into 1 x 1-cm samples and mounted onto the Instron tensiometer. Samples were loaded to failure at a 100% strain rate and force-elongation curves were generated. MLF was defined as the minimum force needed to tear the tissue. Stiffness was determined by the slope of the linear portion of the force/elongation curve between 5 and 15% strain. Statistical analysis was performed using Student's t-test. There is no statistical difference in both MLF and stiffness among ARF, SD, and DG. These data show that MLF and tissue stiffness of SD and DG are comparable to that of ARF. FD has a significantly lower MLF and is significantly less stiff than ARF, SD, and DG. The SD cadaveric fascia lata allograft and the cadaveric dermal allograft may be suitable alternatives to ARF for pubovaginal sling surgery.