FIGURE 7 Route of transobturator sling minimizes anatomical hazards
The needle travels around the ischiopubic ramus. Transobturator needle passage begins with penetration of the skin and subcutaneous tissue. After traversing the superficial perineal fascia, the needle crosses the adductor muscles of the thigh near their pubic bone origin and below the insertion point of the adductor longus tendon (arrow). It then penetrates the obturator membrane, obturator internus muscle, and periurethral endopelvic fascia. After passing the level of the white line—either over or under the puborectalis section of the levator—the needle exits through the vaginal incision.
FIGURE 8 The obturator foramen
The tough obturator membrane covers the foramen. The obturator canal is 2 to 3 cm long and is located at the anterolateral upper margin of the membrane. The distance between the safe zone for needle insertion and the obturator canal is approximately 3.5 to 4 cm. At the safe entry zone (green area), the anterior branch of the obturator artery is reduced to a capillary diameter and no significant arteries, veins, or nerve pedicles are present.
FIGURE 10 Routes of transobturator and retropubic slings
Graphic depiction of both the transobturator sling and the retropubic tension-free sling in place.
Fluoroscopic image of both slings in a cadaver. The transobturator sling runs horizontally while the retropubic tension-free sling forms a tighter “U.”
Clinical experience yields positive results
Early European series and our initial experience suggest that the short-term efficacy of the Monarc transobturator sling is similar to that of the SPARC and TVT slings. Average operating time is 17 minutes. The technique involves a short learning curve (approximately 4 cases).
Cystoscopy is not routinely required; we perform it only in women with significant prolapse or suspected urethral injury, and have encountered no intraoperative or post-operative complications.
No major vessels or nerves come in contact with the transobturator tension-free sling.
No patients have complained of postoperative pain in the area of the adductor muscles of the thigh, and no sling erosions have occurred. We also have found this approach useful in obese patients and women with retropubic scarring, in whom retropubic needle passage can be a challenge.
In addition to its application in the treatment of female stress urinary incontinence, the transobturator foramen route was recently used to insert the anterior wings of a large mesh in the repair of severe cystocele.27
Although long-term follow-up data are not available for the transobturator approach, short-term results are encouraging. Large comparative studies with other anti-incontinent procedures are needed.
Dr. Pelosi II reports that he is a consultant for American Medical Systems. Dr. Pelosi III reports no affiliations or financial arrangements with any companies whose products are mentioned in this article.