Role of intrinsic sphincter deficiency with and without urethral hypomobility on the outcome of tape insertion

AIMS: Intrinsic sphincter deficiency (ISD) is a known risk factor for therapy failure after tension-free vaginal tape (TVT) insertion. The purpose of this study was to investigate if the severity of ISD alone or other factors such as urethral mobility and tape localization influence outcomes. METHODS: One hundred and nine women with urodynamically determined ISD, a TVT insertion, and a 6-month follow-up visit were included. Urethral length, mobility, and tape localization were evaluated by pelvic floor sonography. Patients were classified into three urethral mobility groups (hypomobile, normomobile, hypermobile). Surgical outcome was assessed by a combination of objective and subjective criteria. RESULTS: Therapeutic success rate after TVT insertion was 81.6%. The severity of ISD did not associate with therapy failure. But urethral mobility (P < 0.0001), relative tape position (P = 0.0003), and tape-urethra distance (P < 0.0001) differed between cured and not cured patient groups. Patients with a relative tape position toward 1/2 of urethral length had a higher cure rate. Significantly different cure rates (P = 0.0003) were found for hypomobile (67%), normomobile (76%), and hypermobile (100%) urethras. For ISD patients with a hypomobile urethra, highest cure rates were obtained for tape-urethra distances between 2.5 and 3.5 mm. CONCLUSIONS: The reduced cure rate for ISD patients was due to the subgroup with a hypomobile urethra. A prospective study is needed to confirm that slightly shorter tape-urethra distances and a relative tape position more toward the mid-urethra will lead to better outcomes for this patient group.