PATIENT SELECTION

When the procedure for TVT was introduced, all female patients with SUI who had maximized their nonsurgical treatment were considered candidates for this procedure.^2,³ As with all anti-incontinence procedures, relative contraindications included an active urinary tract infection and anticoagulation therapy. Although no procedure is 100% effective, recent studies on the outcomes of patients undergoing the TVT procedure provide an opportunity to make some basic selection criteria for ensuring a high rate of successful outcomes.²^–⁴ As described in the following paragraphs, there may be potential patient selection limitations for midurethral slings that are not inherent in the traditional pubovaginal sling placed at the proximal urethra and bladder neck.

In general, moderate to severe obesity is not a contraindication; obese patients appear to have minimal operative and postoperative complications with the TVT procedure.⁶ Successful outcomes are achieved when the TVT procedure is performed in patients undergoing concomitant pelvic organ prolapse repairs. Major complications of vascular injury and bowel injury leading to death are unique to the TVT procedure as secondary consequences of blindly passing large trocars in a retrograde, retropubic fashion. Although major vascular bleeding and possibly bowel injuries have been rarely reported with other anti-incontinence procedures, the inability to reliably prevent these complications from occurring at all has been the major reason for surgeons’ opting to place the midurethral sling using small, percutaneous ligature carriers in an antegrade, retropubic fashion.^5,⁷ By this method, the ligature carrier can be safely guided along the posterior aspect of the symphysis pubis, thereby decreasing risks for vascular or bowel injury.

Because the sling material for PVT and TVT are placed at the mid-urethra, continence is provided by midurethral kinking or “knee kinking” of the urethra during active movement of the urethra with Valsalva or stress maneuvers. This has several important implications in regard to patient selection. First, although several reports have shown that correction of the hypermobile proximal urethra and bladder neck demonstrated by magnetic resonance imaging (MRI) and Q-tip testing is not required for a successful outcome, successful outcome appears to be dependent on a hypermobile urethra that induces ISD.⁸ The midurethral placement of the sling is at the fulcrum of the mobile urethra and does not affect displacement of the urethra and bladder neck as defined by Q-tip testing. However, for the sling to provide a continence mechanism, the urethra must be actively “bent” over the midurethral sling, in order to prevent urinary leakage during stress maneuvers. Therefore, patients with a mobile urethra demonstrating significant hypermobility (>30 degrees) with SUI in the absence of a bladder contraction would seemingly have the highest probability for a successful outcome.

Alternatively, patients with severe ISD at rest with or without hypermobility are more likely to have less favorable outcomes. Severe ISD is indicative of an open bladder neck at rest and is not affected by a midurethral sling that is placed tension-free without causing an increase in urethral resistance at rest. Even in cases of severe ISD and a hypermobile urethra, leakage may occur with an open bladder neck before any urethral movement begins to provide coaptation by “kinking” of the midurethral sling. No prospective reports have been published on preoperative leak point pressures before TVT placement and postoperative leak point pressures on failed cases of TVT.

OPERATIVE TECHNIQUE OF PERCUTANEOUS VAGINAL TAPE PLACEMENT

Midurethral Sling

Obtain vaginal exposure via the dorsal lithotomy position. Use a marking pen to draw the abdominal percutaneous puncture and midurethral vaginal wall incision sites. Place a 16-Fr urethral catheter into the bladder (Fig. 43-1).

Figure 43-1 Marking of a midline anterior vaginal wall incision over the mid-urethra.

Vaginal Incision

Use a scalpel to make a midline anterior vaginal wall incision at the level of the mid-urethra. Develop a pocket of space at the level of the mid-urethra between the vaginal wall and underlying urethral and paraurethral tissue by dissecting the vaginal wall tissue off laterally with the curved Mayo scissors from the 1.5- to 2.0-cm midline incision to the lateral anterior vaginal sulcus. No true entry into the retropubic space is required (Fig. 43-2). When the pocket of space is completed laterally to the junction of the inferior aspect of the pubic ramus and the urethropelvic complex (Fig. 43-3), one can proceed with antegrade passage of the needle carrier.

Figure 43-2 Development of a suburethral anterior vaginal wall pocket.

Figure 43-3 Suburethral pocket opened to confluence of endopelvic and periurethral fascia.

Before the percutaneous ligature carrier is passed (Fig. 43-4), the bladder should be emptied of all fluid. The patient’s position on the operating table should result in placement of the symphysis pubis in a near-vertical plane; this usually means keeping the patient’s torso and head in a level horizontal position or slightly in a Trendelenburg position.