Synthetic Midurethral Slings and the Attractiveness of TOT

Based on the results of 14-week postoperative urodynamic testing that was completed by about 66% of the patients, we found no significant difference in the percentage of patients cured of stress urinary incontinence (97% TVT vs. 90% TOT). And based on results of postoperative quality-of-life questionnaires, we concluded that subjective cure rates were similar between the groups (87% TVT vs. 89% TOT).

TOT did, however, offer the advantage of significantly less postoperative retention and lower rates of de novo urge urinary incontinence. Just as other data have shown, we've found that patients get back to normal voiding sooner with TOT. There was also a trend toward better resolution of urge urinary incontinence with TOT in these women with mixed incontinence symptoms.

Research suggests that we can achieve the same outcomes with either the outside-in or inside-out approach. Dr. Harry Vervest of Tilburg, the Netherlands, recently completed a randomized comparison of the outside-in and inside-out approaches in 75 women and found no significant differences in intraoperative or postoperative characteristics of the two procedures. Other studies have had similar conclusions.

Dr. Vervest looked at factors such as type of anesthesia, length of surgery, and amount of blood loss, as well as the length of catheter use and postoperative voiding parameters. He has reported that there were no complications with either method.

For me, however, the outside-in approach is a better choice. For one thing, I like to insert the needle where I have the most control. And overall, the outside-in approach is simpler than the other technique and does not result in the medial thigh pain that we hear about with the inside-out technique.

There are three different types of mesh-passer systems available. They use specially designed helical, curved, or hook needles. With each of these systems, the outside-in procedure involves three small incisions and the following essential steps:

A small vertical incision is made on the lateral edge of each labium majorum, medial to the labiocrural fold and posterior to the base of the adductor longus tendon. Once you identify the tendon, you'll find a depressed area that is the obturator foramen about an inch below the tendon. You can make a small stab wound on the medial edge of the obturator foramen bilaterally.

Another vertical incision is made on the anterior vaginal wall under the midurethra. You can dissect the vaginal epithelium from the underlying periurethral connective tissue, and then bluntly dissect under the vaginal epithelium about 2 cm bilaterally.

Then you can spread the scissors wide enough so that you can insert your index finger and point it toward one of the labiocrural incisions.

Starting with the right-side incision, you will angle your right index finger toward the incision in the labiocrural fold. The tip of the right-handed needle can then be pushed with your right thumb along the posterior surface of the ischiopubic ramus. You'll push through the obturator externus muscle, the obturator membrane, and the obturator internus muscle, feeling three separate pops before you feel the needle on your right index finger behind the endopelvic connective tissue.

Once you ensure that the needle is truly free of the overlying vaginal epithelium, you can connect the polypropylene mesh to the needle and rotate the needle back out through the obturator foramen. The same procedure can then be repeated on the other side.

To establish proper tension, I like to place a right-angle clamp between the urethra and under the mesh and open it approximately 1 cm. I also check to ensure that the weave of the mesh below the urethra looks exactly like the weave of the mesh that exits through the labial incisions without any tension.

Some physicians use spacing devices, but I like to look at the mesh visually. If the mesh underneath the urethra does not look distorted and looks similar to the mesh protruding through the skin, then I know the sling is not under tension. I'll then go ahead and trim the mesh back against the skin and use simple sutures to close the incisions on each side.

The safety of this approach is ensured by fingertip guidance of the needle through the obturator membrane and the positioning of the index finger toward the incision and the cross-arm of the needle. This way, you're essentially opposing your thumb and index finger, ensuring proper passage of the needle.

Some physicians worry about the obturator canal's being several centimeters away from the path, but I believe that any injury would more likely occur through the inside-out approach.