Master Class
Dr. Sokol’s transobturator (TOT) approach
I most often use an outside-in sling. I utilize the same patient positioning and identify the midurethral point in the same way as with the retropubic approach.
On the thigh, I identify the adductor longus tendon as well as a little soft spot or depression just beneath the tendon and lateral to the descending ischial pubic ramus. With my thumb on the soft spot, I can actually grasp the adductor longus tendon between my thumb and index finger. This spot, which is also approximately at the level of the clitoris, marks the entry point for sling placement. It is the thinnest point between the groin and the vagina at the level of the midurethra.
I perform a similar hydrodissection under the urethra as I do in a retropubic procedure, though instead of injecting 5 cc’s to the underside of the pubic symphysis on each side, I instead inject toward the obturator internus muscles. I then inject my final syringe of dilute vasopressin saline solution at the groin poke incision sites, directed toward the projected trocar path, as opposed to suprapubically.
After the full-thickness vaginal incision is made with the scalpel, the dissection is performed sharply with Metzenbaum scissors and is more like the dissection done for cystocele repair than for a retropubic sling. Rather than a poke, the midurethral incision is long enough – about 1.5 cm – for me to reach a finger behind the obturator internus muscle after having sharply dissected the suburethral tissue and fascia. The angle of the dissection is more lateral than for a retropubic sling, toward the underside of the descending ischiopubic ramus and obturator internus muscle.
To place the sling, I have one hand with an index finger in the midurethral tunnel under the obturator internus muscle to protect the urethra. The thumb of that same hand is used to push the helical trocar straight through the thigh poke incision with the handle starting at a 35-degree angle from vertical. The trocar tip is pushed until it can no longer go straight and is ready to be tightly turned around the descending ischiopubic ramus with the opposite hand. A distinct pop can be felt as the trocar tip advances through the obturator membrane and muscles. As the tip is advanced, the angle of the trocar is rotated from 35 degrees to vertical, almost perpendicular to the floor. At this point, the tip of the trocar should be guided out of the midurethral tunnel against the opposite index finger.
I utilize the same technique for tensioning a TOT sling as I do the retropubic sling.
Dr. Rardin’s retropubic approach
I continue to use the original TVT sling with a 5-mm stainless steel, mechanically cut trocar and reusable handle. The newer slender needles may advance with less pressure, but I worry about them bending during passage. I feel more assured and comfortable using the older trocars.
Courtesy of Dr. Charles Rardin
I perform retropubic hydrodissection with a spinal needle using a top-down approach. With 40 cc of a very dilute solution of bupivacaine (Marcaine) with epinephrine on each side of the urethra, I create columns of hydrodissected space. Studies are inconsistent about the benefits of hydrodissection, but theoretically, it decreases the risk of bladder injury by pushing the bladder away from the pubic bone, creates effective hemostasis, and can provide analgesia that will be on board when the patient wakes up.
I bring the spinal needle down behind the pubic bone to the location of the urethral incision site, with my finger in the vagina, so I can feel the tip of the needle next to the urethra/Foley catheter. For each side, I will inject 20 cc of the solution in this location, and the other 20 cc as I withdraw the needle upward.
For trocar passage, some surgeons are taught to advance the trocar until a pop is felt, then drop the handle and push upward. I view the maneuver as a consistent, smooth arch; for every degree that I advance the trocar, I drop the handle slightly in order to maintain contact with the back of the pubic bone throughout the pass. I continuously and simultaneously drop the handle and advance the trocar. Contact with the back of the pubic bone is maintained with a slight pulling on the back end of the trocar handle, while the forward hand pushes the trocar upward.
Courtesy of Dr. Charles Rardin
The target that I visualize for a retropubic pass is the patient’s ipsilateral shoulder. A cadaver study showed that if you aim as far lateral as the patient’s outstretched elbow, you can enter the iliac vasculature (Obstet. Gynecol. 2003;101:933-6).
If the patient is draped such that I cannot see the ipsilateral shoulder, I ask the anesthesia team to show me. I have also identified and marked the suprapubic points about 2-3 cm from each other on either side of the midline just about the pubic symphysis, but I consider the broader anatomic picture and purposeful visualization toward the ipsilateral shoulder to be an essential part of safe technique. In general, it is safer to be more medial than more lateral for the needle passage.
I continue to use a rigid catheter guide to deflect the bladder neck while passing the needles.
Dr. Charles Rardin
Cystoscopy is performed after both needles are placed but not yet pulled through. I fill the bladder until the ureteral orifices appear flattened, which confirms that the bladder is under enough distension to preclude any mucosal wrinkles.
The technique I utilize for adjusting the tension of the TVT sling was taught to me by Dr. Peter L. Rosenblatt of Mt. Auburn Hospital in Cambridge, Mass. At the midline of the sling, I advance the sheaths just enough so that I can grasp a 2-3 mm “knuckle” of the midportion of the sling with a Babcock clamp. I then pull the sling ends until the Babcock comes into gentle contact with the suburethral tissue. The sheaths encasing the sling are then removed and the Babcock clamp is released to assure a tension-free deployment.
The amount of tape that is pinched with the Babcock – the size of the “knuckle” – determines the tension. For a patient with a more profound problem, such as intrinsic sphincter deficiency or a lack or urethral hypermobility, I will grasp a smaller knuckle.
These steps ensure that the midportion of the tape will not tighten or become deformed under tension. Rather than use a spacer, I like to protect the midportion of the tape and prevent it from being stretched. I find that the approach is reproducible and results in a reliable amount of space between the urethra and sling when the procedure is completed.