MODIFIED RECTUS FASCIAL SUBURETHRAL SLING

INTRODUCTION:
Suburethral sling procedures have been used to treat urinary incontinence secondary to nonfunctional internal sphincter since the turn of the century. Slings can be formed from organic material like round ligament, rectus fascia, and fascia lata. The major problems encountered with the organic materials are mainly due to insufficient length and inconsistent tensile strength.

Urinary retention and refractory bladder instability are the main complications. Inorganic materials, like Marlex, have been used. In addition to retention and bladder instability, foreign body reaction, draining sinus, infection, and erosion are reported with inorganic slings.

Suburethral sling procedures have traditionally been reserved for the treatment of recurrent stress incontinence (SUI), especially in those women with immobile urethra. Recently, there is a more expanding role of sling procedures in SUI secondary to weak support of the vesicourethral segment, specially in obese women and those with weak and unsatisfactory pelvic fascial and ligaments. The modification described herein avoids most of those problems and simplifies the procedure as well as corrects mild cystocele.

SURGICAL TECHNIQUE:
The surgeon's operative skill, familiarity with the procedure, and personal preference will determine what material to use and how to use it. Rectus fascia, fascia lata and lyophilized dura are the most popular organic sling materials, while Marlex and, more recently, Gore-tex, are the most commonly use for an inorganic sling.

Since 1987, we have used the modified pubovaginal sling (MPVS) in >170 patients with complicated stress urinary incontinence. A modification of McGuire's free rectus fascia sling was used in all patients.

1.) Preparation of the patient for a sling operation is similar to that for any other genitourinary operation: a detailed history, physical examination, voiding diary, routine preoperative blood and urine analysis, radiological and urodynamic evaluations. The presence of any other abnormality, such as detrusor instability, stones, tumors, fistulae, diverticula, or any manifestation of pelvic floor relaxation should be recognized and included in the final planning before surgery. For example, concomitant partial bladder denervation could be done in conjunction with an anti-incontinence procedure for incontinent patients with severe pre-operative detrusor instability.

2.) The patient is placed in a full lithotomy position. Prior to induction of anesthesia, a sequentional compression device is fitted to the lower limbs. This is specially important in obese females to prevent pulmonary emboli. Abdominal and vaginal preparation and draping are performed in a standardized fashion. Stay sutures are used to retract labia and a weighted vaginal retractor is placed. A urethral catheter is placed, and 15 cc of water are used to inflate the balloon for better identification of the bladder neck.

3.) Through a Pfannenstiel suprapubic incision, an anterior rectus fascial flap measuring 7x2.5 cm is harvested and placed in an antibiotic solution (Fig. 1). The fascia is defatted and number 1 polypropylene suture is placed in a helical manner on each end. To ensure strong attachment of the suture to the sling, each edge is rolled and the suture is then anchored to it. Tying the suture at each end should not strangulate the fascia. The retropubic space is developed carefully and previous suspension should be taken down. Cystourethrolysis is performed so as to feel the back of the symphysis pubis, the balloon of the Foley's catheter and the paravaginal fascia without difficulty. This is an important step to free the vesicourethral segment from adhesions that would prevent the bladder neck from coating during stress. Also, the tip of the suture carrier needle can be guided to the paravaginal space safely without transfixing the bladder wall.

4.) Vaginal dissection is facilitated by saline infiltration. Through an inverted "U" anterior vaginal incision centered around bladder neck, the vesico-urethral unit is exposed and dissection is carried laterally to the endopelvic fascia. The endopelvic fascia is detached from its attachment to arcus tendinous under the pubic bone just enough to admit a finger into the retropubic space. A Stamey or Raz suture carrier needle is passed through suprapubic incision on each side and guided into the vaginal space. The polypropylene suture is threaded into the eye of the needle and then brought to the suprapubic area (Fig. 2). The sling is then centered behind the posterior urethra and bladder neck. On each side, the sling is fixed proximally into the pubo-cervical fascia and distally into the pubo- urethral ligaments using polyglactin sutures (Fig. 3) Cystoscopy is performed to rule out bladder perforation by the sutures. Closure of the anterior vaginal wall is performed using chromic catgut suture in a continuous interlocking manner. The rectus fascia is closed by a continuous PDS suture. The free ends of the polypropylene suture are passed through a small teflon pledget and tied individually over the rectus fascia and then tied together loosely, admitting an index finger, in the suprapubic area. The suprapubic incision is then closed in a regular fashion. A vaginal pack soaked with antibiotic cream, is placed and left for one day. The patient is discharged on the first or second postoperative day. One week postoperatively, the patient is seen in the clinic and a voiding trial is performed. Residual urine determination is performed and, if significant, clean intermittent catheterization program is started. Suprapubic catheter is used in patients who cannot perform self-catheterization as demonstrated preoperatively. Limited activity is gradually increased to full activity within 6 weeks. The patient is instructed to avoid strenuous activity and sexual intercourse for 6 weeks.

CONCLUSION:
Sixty-eight (85%) of the patients were cured of their incontinence. Additionally, eight patients (10%) were significantly improved (using one or less pad per day). The overall success rate is 95% with no significant difference between patients who underwent MPVS as a single procedure or who had concomitant reconstructive pelvic surgery. The group who underwent concomitant reconstructive surgery showed a higher incidence of blood loss, bladder and bowel laceration, upper respiratory tract infection, wound infection, vaginal bleeding, and pelvic prolapse (12 out of 14).