Transobturator Mid-Urethral Sling
The transobturator mid-urethral sling (TMUS, TOT, TVT-O) treats female stress urinary incontinence by placing a polypropylene tape beneath the midurethra through the obturator foramen rather than the retropubic space.[1][2] Its main appeal is lower bladder and retropubic vascular injury risk; its signature tradeoff is groin or thigh pain.[2][3]
This page focuses on the transobturator route. For shared MUS counseling and FDA context, see Female Slings & Suspensions.
Indications
TMUS is best suited for patients with uncomplicated hypermobility-predominant SUI who want a full-length synthetic sling while avoiding retropubic passage.[2][4]
| Scenario | Why TMUS fits |
|---|---|
| Hypermobility-predominant SUI | Provides midurethral support with cure rates overlapping RMUS in many trials |
| High concern for bladder perforation | Bladder perforation is substantially lower than with RMUS[2][3] |
| High concern for postoperative retention | Voiding dysfunction is lower than RMUS in comparative data[2][3] |
| Hostile retropubic space | Avoids prior retropubic dissection planes |
Relative reasons to avoid TMUS include chronic groin pain, obturator neuralgia, major adductor pain syndromes, severe intrinsic sphincter deficiency, or patient preference for the longest retropubic evidence base.
Routes
| Route | Direction | Practical note |
|---|---|---|
| Outside-in TOT | Groin incision to vaginal incision | Delorme-style route |
| Inside-out TVT-O | Vaginal incision to groin incision | de Leval-style route; similar efficacy and fewer vaginal perforations than outside-in passage in some comparative analyses[5] |
Both routes place the tape in a flatter, more transverse vector than RMUS. The route lowers retropubic risk but places the sling arms near the obturator internus, adductors, and obturator neurovascular compartment.
Technique
Inside-out TVT-O
- Place the patient in dorsal lithotomy and insert a Foley catheter.
- Make a midurethral vaginal incision.
- Develop lateral paraurethral tunnels toward the inferior pubic ramus and obturator membrane.
- Make bilateral groin crease exit incisions at the planned trocar exit sites.
- Pass the helical trocar from the vaginal incision through the obturator membrane and obturator foramen to the groin incision.
- Repeat contralaterally.
- Adjust the tape tension-free under the midurethra.
- Consider cystoscopy for difficult passage, hematuria, prior surgery, or concern for urinary tract injury.
- Trim the tape at the skin and close vaginal and groin incisions.
Technical rules
- Aim lateral, not cephalad; this is not a retropubic dissection.
- Keep the tape flat and symmetric before removing sheaths.
- Do not overcorrect: TMUS is still a tension-free sling.
- Counsel about transient groin / thigh pain before surgery so expected early discomfort does not become a surprise.
Outcomes
TMUS has short-term subjective cure rates broadly overlapping RMUS, but some network meta-analyses rank RMUS modestly higher for cure.[2][5][6] AUA/SUFU notes that long-term durability comparisons remain mixed rather than definitive.[4]
| Outcome | TMUS counseling point |
|---|---|
| Efficacy | Similar to RMUS in many RCTs; may be less effective in ISD-heavy populations |
| Bladder perforation | About 0.4-0.6%, markedly lower than RMUS[2][3] |
| Voiding dysfunction | Lower than RMUS in comparative data[2][3] |
| Groin / thigh pain | Higher than RMUS; usually self-limited, occasionally persistent[2][3] |
| Mesh exposure | No consistent difference from RMUS[2] |
Operative Pearls
- TMUS is attractive when the retropubic space is the problem; it is less attractive when the obturator compartment is the problem.
- A patient with fixed urethra or severe ISD may need RMUS, autologous fascial pubovaginal sling, or another outlet strategy instead.
- Persistent focal groin pain after TMUS should trigger evaluation for mesh arm pain, obturator neuralgia, or pelvic floor myalgia.
- Cystoscopy is not universally mandatory for straightforward TMUS, but a low threshold is reasonable when the pass is difficult.
References
1. Wu JM. "Stress Incontinence in Women." N Engl J Med. 2021;384(25):2428-2436. doi:10.1056/NEJMcp1914037
2. Ford AA, Rogerson L, Cody JD, Aluko P, Ogah JA. "Mid-Urethral Sling Operations for Stress Urinary Incontinence in Women." Cochrane Database Syst Rev. 2017;7:CD006375. doi:10.1002/14651858.CD006375.pub4
3. Richter HE, Albo ME, Zyczynski HM, et al. "Retropubic versus Transobturator Midurethral Slings for Stress Incontinence." N Engl J Med. 2010;362(22):2066-2076. doi:10.1056/NEJMoa0912658
4. Kobashi KC, Vasavada S, Bloschichak A, et al. "Updates to Surgical Treatment of Female Stress Urinary Incontinence (SUI): AUA/SUFU Guideline (2023)." J Urol. 2023;209(6):1091-1098. doi:10.1097/JU.0000000000003435
5. Fusco F, Abdel-Fattah M, Chapple CR, et al. "Updated Systematic Review and Meta-Analysis of the Comparative Data on Colposuspensions, Pubovaginal Slings, and Midurethral Tapes in the Surgical Treatment of Female Stress Urinary Incontinence." Eur Urol. 2017;72(4):567-591. doi:10.1016/j.eururo.2017.04.026
6. Imamura M, Hudson J, Wallace SA, et al. "Surgical Interventions for Women With Stress Urinary Incontinence: Systematic Review and Network Meta-Analysis of Randomised Controlled Trials." BMJ. 2019;365:l1842. doi:10.1136/bmj.l1842