Experimental evaluation of free versus pedicled fascial flaps for sling surgery of urinary stress incontinence

Purpose: Bladder neck suspension using an autologous fascial sling is an established surgical technique for treatment of urinary stress incontinence. However, the biological fate and physical properties of autologous fascial sling yet remain to be determined. Materials and Methods: Our study was designed to evaluate in an animal model of twenty rabbits fascial slings from free and pedicled fascial flaps of two different widths (7 mm and 15 mm.) and uniform length (60 mm.) in respect to changes of length, width, tensile strength and histological criteria of vitality and integrity 3 months after surgery. Results: The results 3 months after surgery revealed shrinkage in length by 37% (31%-46%) of the original length, shrinkage in width by 63% (60%-69%) of the original width and reduction of tensile strength of 53% (51%-55%) without consistent differences between free and pedicled flaps or 7 mm. and 15 mm, wide flaps. In the groups with 7 mm. wide flaps a total of two dystrophic slings (1 pedicled, 1 free) were seen; however, no dystrophies were seen in 15 mm. wide flaps. On microscopy, all slings were vital regardless of their surgical configuration. Conclusions: In summary, on macroscopic, microscopic and physical examination no gross differences between free and pedicled slings could be detected, so that preferences for use of free or pedicled fascial flaps could not be established for clinical applications in sling surgery. However, 15 mm. wide flaps had a lower incidence of dystrophy and retained greater absolute tensile strength than 7 mm. wide flaps.