Trans-obturator urethral sling for the surgical correction of female stress urinary incontinence: outside-in (Monarc) versus inside-out (TVT-O). Are the two ways reassuring?

INTRODUCTION: In 2001, the trans-obturator route was proposed for the surgical positioning of tape with a view to avoiding the retropubic space and its disadvantages. The route, originally described outside-in by Delorme was presented inside-out by de Leval. Since then, anatomical discussions have attempted to prove that one technique is safer than the other.

OBJECTIVE: Demonstrating the safety of the two techniques through personal and published experience.

MATERIAL AND METHODS: Non-randomized, prospective, observational, open-label, longitudinal study of 100 female patients (50 tension-free vaginal tape (TVT)-O and 50 Monarc). All the female patients presented with isolated stress urinary incontinence. Only four patients presented with mixed incontinence in the Monarc (MON) group. Sphincter incompetence was observed four times in the MON group and three times in the TVT-O group. Almost all the patients were undergoing their first procedure. All the patients underwent surgery under assisted local anesthesia in a day-hospital setting. All the patients underwent a full gynecological examination and a urodynamic assessment. Only those patients presenting with patent established urinary incontinence, corrected by the TVT test, underwent surgery. Post-operative control was conducted at 3 months and 1 year when a physical examination and urodynamic assessment were implemented.

RESULTS: All the patients underwent control up to time point 12 months. The duration of hospitalization was 10h for 48 patients in the MON group and 49 in the TVT-O group. The duration of hospitalization was 24h for one patient in each group and 4 days for one patient in the TVT-O group due to transient urine retention. The only per-operative complication was a vaginal perforation in the lateral angle of the vagina for a MON patient. Tape repositioning was necessary. Early post-operative complications were observed in the MON group: three cases of urinary tract infection, one of transient urine retention, three of pain in the thighs spontaneously resolving within 4 days and one of permanent pain in one leg at time 1 year, which remained bearable. For the TVT-O group the post-operative complications consisted in: one case of urinary tract infection, one of transient retention and four of pain in the thigh. No hematoma was reported in either group. Amongst the late complications, the de novo symptoms included one case of imperious urges to urinate in the TVT-O group and objective dysuria in two cases in the MON group versus seven in the TVT-O group. There was no statistically significant between-group difference in the complications. No tape exposure was observed. Overall, the recovery rate was 90% at 1 year for MON versus 94% for TVT-O (p=NS) with two cases of recurrence between 3 months and 1 year in that series. Mixed incontinence was corrected at time point 1 year in 75% of cases for MON, with one case of recurrence in the year. For the patients presenting with sphincter incompetence, competence was maintained at 3 months and 1 year in all cases in the MON group. The three TVT-O were cured at 3 months, but two recurrences were observed at 1 year. Almost all the patients were satisfied or very satisfied at time point 1 year and those who had sexual relations (54%) did not report any disorder at time point 1 year.

DISCUSSION: The outside-in technique necessitates more marked peri-urethral dissection and vesical complications are possible. The cadaveric studies by the outside-in partisans show a vascular and nervous risk, which has little reflection in terms of complications in the literature. Post-operative leg pains are encountered with both techniques and are usually only transient. All the studies of the two routes report a recovery rate of over 90% for pure stress incontinence.

CONCLUSION: The author's experience, like that reported in the literature, shows that the two trans-obturator access routes are equally safe and do not require per-operative cystoscopic control. The clinical results would appear to be equivalent, in terms of recovery, to the rates obtained with retropubic TVT. Attempting to find anatomical or etiological arguments in order to prove one technique superior to the other appears somewhat parochial.