OBJECTIVE: This study evaluates a transobturator approach for placement of a tension-free midurethral sling with regard to safety and efficacy for the treatment of stress urinary incontinence (SUI). METHODS: One hundred twelve female subjects were enrolled between July 2003 and May 2004 in an Institutional Review Board-approved prospective, multicenter study and implanted with the Monarc Subfascial Hammock (American Medical Systems, Minnetonka, MN), a tension-free suburethral polypropylene sling. All subjects had confirmed SUI resulting from urethral hypermobility with or without intrinsic sphincter deficiency (ISD). Subjects were excluded if they had previous suburethral sling procedures, uncontrolled detrusor instability, or significant pelvic organ prolapse (extending beyond the hymen). Preoperative objective evaluation included urodynamic testing (UDT), cough-stress test, Q-Tip test, 1-hour pad test, and POP-Q examination. Subjective evaluation included quality-of-life questionnaires (QOL), the UDI-6, and IIQ-7. Procedural and 4- to 8-week postoperative follow-up data were gathered. The preoperative evaluations (minus UDT) were repeated at 6 months postoperatively. Adverse events (AEs) were reported across all evaluations. RESULTS: Mean age was 56.9 years (30–88 yrs) and average time with incontinence was 6 years (<1–40 yrs). Mean preoperative ALPP was 76 cm H2O (0–258 cm). Mean operating time was 19 minutes (5–73 minutes) and mean blood loss was 34 cc (2–250 cc). Forty-four percent subjects had concomitant repairs. Mean time to urinate without a catheter was 13.4 hours (<1–144 hours) for subjects who underwent Monarc only and 16.4 hours (0–96 hours) for subjects with concomitant repairs. Seventy-eight percent subjects treated with Monarc alone went home without a catheter. One intraoperative adverse event was observed—one vaginal skin perforation (repaired with a suture). Of the 108 patients who completed a 4- to 8-week follow-up visit, 98 (90.7%) subjectively reported being completely dry or substantially continent (not requiring protection). Currently, 58 subjects have completed 6-month follow up with an objective cure rate of 87.9% as defined by a negative cough-stress test. Average pad use per day decreased from 2 pads (0–11 pads) preoperatively to one pad (0–6 pads) at 4–8 weeks and 0.2 pads (0–3 pads) at 6 months postoperatively. Improvements in global QOL scores were statistically significant (P<0.001). Thirty (26.8%) subjects reported preoperative urge symptoms; all of whom reported no urge symptoms at 6 months. Twenty-one (18.8%) subjects developed de novo urge; of those, 48% were taking medication at 6 months. Nineteen device-related AEs were reported in 39 (34.8%) subjects. Device-related AEs (from procedural data in 112 patients) include: 3 (2.7%) UTI, 3 (2.7%) mesh extrusion, 2 (1.8%) pain (abdominal, musculoskeletal), and one (0.9%) each urinary retention, bacterial vaginosis, dysuria, incomplete bladder emptying, rectocele, leg numbness (resolved spontaneously with no nerve injury reported), and abscess of groin incision (suture removed, resolved). Treatment failure resulting in revision of the sling occurred in 4 (3.6%) subjects and sling extrusion into the vagina resulted in one (0.9%) revision. CONCLUSION: Preliminary data shows the Monarc transobturator sling procedure to be a safe and effective treatment of SUI with an objective cure rate of 87.9% at 6 months. No urethral, bladder, bowel, or vascular perforations or hematomas were reported in 112 patients. Return to normal voiding was rapid with minimal voiding dysfunction. Long-term follow-up data are necessary; subjects will be followed through 24 months.