Urinary stress incontinence due to intrinsic sphincteric deficiency: Experience with fat and collagen periurethral injections

Purpose: We prospectively compared the efficacy of 2 bulking agents to treat incontinence related to intrinsic sphincter deficiency. Materials and Methods: A total of 67 women underwent periurethral injection for intrinsic sphincter deficiency at the same institution performed by 1 surgeon. Patients were divided into 45 who received fat (group 1) and 22 who received collagen (group 2) injections. Both groups were comparable for age, parity, number of previously failed procedures and number of pads used daily. Preoperative urodynamic evaluation revealed a low Valsalva leak point pressure in both groups (mean plus or minus standard deviation 23.82 +/- 12.41 versus 29.35 +/- 11.32, not significant). Patients rated the subjective degree of postoperative improvement as 0 to 100%. Results: At a mean followup of 7 months after the last injection only 13% of the fat group and 24% of the collagen group were cured. The mean percentage of subjective improvement was significantly greater in the collagen than in the fat group (70.9 +/- 28 versus 31.2 +/- 41.7%, respectively, p <0.001). The failure rate was significantly greater in the fat group compared to the collagen group (p <0.001). Conclusions: Based on results of a prospective comparison of fat and collagen injection, collagen is more effective than fat for treatment of intrinsic sphincter deficiency.