Commented Abstracts

Correlation of Morphological Alterations and Functional Impairment
of the Tension-Free Vaginal Tape Obturator Procedure
The Journal of Urology, Vol. 181, 211-218, Jan 2009

Jenn-Ming Yang, Shwu-Huey Yang and Wen-Chen Huang*
From the Division of Urogynecology, Department of Obstetrics and Gynecology, Mackay Memorial Hospital (JMY), Schools of Medicine (JMY, WCH) and Nutrition and Health Sciences (SHY), Taipei Medical University, Department of Obstetrics and Gynecology, Cathay General
Hospital (WCH) and School of Medicine, Fu Jen Catholic University (WCH), Taipei, Taiwan, Republic of China

Purpose: We explored the morphological features associated with functional impairment in patients undergoing the tension-free vaginal tape obturator procedure.

Materials and Methods: We retrospectively reviewed the records of 98 women who underwent the tension-free vaginal tape obturator procedure alone or with concomitant pelvic surgery. Postoperative assessment included a symptom questionnaire, ultrasound cystourethrography and a cough stress test. During follow-up the measures of postoperative functional impairment included a positive cough stress test, new onset voiding dysfunction and the worsening or progression of urge symptoms.

Results: Median follow-up was 22 months. During follow-up 11 women had a positive cough stress test, 22 had voiding dysfunction and 12 had worsening or new onset urge symptoms. Failure was associated with 4 variables on multiple logistic regression analysis, including absent urethral encroachment at rest (OR 16.63, 95% CI 1.87–147.85, p < 0.01), bladder neck funneling (OR 8.27, 95% CI 1.99–34.26, p <0.01), a urethral location of less than the 50th percentile (OR 6.01, 95% CI 1.43–25.25, p<0.01) and a resting tape angle of less than 165 degrees (OR 5.21, 95% CI 1.15–23.54, p=0.03). A resting tape distance of less than 12.0 mm (OR 3.00, 95% CI 1.44–6.26, p<0.01) and urethral encroachment at rest (OR 2.86, 95% CI 1.30–6.30, p<0.01) were the variables predictive of postoperative voiding dysfunction. Bladder neck funneling was the only risk factor for postoperative urge symptoms (p<0.01).

Conclusions: The tension-free vaginal tape obturator procedure achieves its effectiveness in a process of biological reaction and mechanical interaction between the tape and urethra. When this mechanical interaction is too great or too little, there is functional impairment after the procedure.

Key Words: urethra; urinary incontinence, stress; sub urethral slings; vagina; ultrasonography


Editor’s comment

The transobturator approach to treat Stress Urinary Incontinence (SUI) aims at providing a firm support for the middle urethra by rebuilding the pubourethral ligaments. In stress situations, there is urethral closure and its compression against the support provided by the sling, thus preventing urinary loss caused by a sudden increase in abdominal pressure. A major advantage, in relation to the retropubic TVT, is that it has lower post-operative obstruction likelihood because of the angles formed by the slings (closed in the TVT and open in the TVT-O). Yang et al evaluated the interaction among the tape, the urethra and the bladder neck. In the cases of surgical insuccess (recurrence or failure), a lack of close contact was clear, which the author characterized as urethral notch of the tape during rest which has been characterized as the main risk factor for the failure. On the other hand, when very prominent, the notch was associated with micturition dysfunction. Among the factors that can be controlled by the surgeon, two were important: the proper tape positioning in the middle urethra (worse results when the tape was placed too proximal) and the “pressure” created by the sling. Unfortunately, there is still no effective method to guide the surgeon in placing the tape near enough the urethra in order to repair the SUI and lax enough so as not to cause obstruction and micturition dysfunction. Regardless of the SUI surgical treatment outcome, proper placement of slings is an art; and experience and common sense are fundamental in order to obtain the best results.

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