Female urethral problems can be debilitating and disturbing to the quality of life in women secondary to problems affecting voiding or devastating incontinence. Reconstruction of the female urethra is technically demanding. Understanding the surgical principals is critical to optimize outcomes. The goal of surgery is to reconstruct the urethra and to obtain a functional urethra that enables the patient to void volitionally and be socially continent. Urethra fistula and urethral diverticula, although both relatively uncommon, are probably the two most common conditions of the female urethra requiring major reconstruction.
RECONSTRUCTION OF THE FEMALE URETHRA FOR FISTULA
In the developing world, the major causes of the development of urethral fistula are related to obstetric trauma secondary to prolonged labor. This is responsible for the development of about 90% of urinary fistula in women (
1). In contrary, in the developed world, urethral damage is most commonly iatrogenic. This can occur secondary to (a) transvaginal surgery such as transvaginal urethral diverticulectomy, bladder neck suspension, anterior colporrhaphy (
2), or vaginal hysterectomy (
Table 37.1); (b) complications caused by erosion of synthetic materials placed during pelvic reconstructive surgery or midurethral sling procedures (
2); (c) obstetric complications from instrumentation during vaginal delivery, such as cerclage sutures (
2); (d) prolonged indwelling urethral catheter in neurogenic disorders; (e) locally invasive malignancies and long-term effects of radiation (
3); and (f) pelvic trauma resulting in laceration of the urethra (
4).
Indications for Surgery
Surgical repair of the injured urethra should be considered in any symptomatic patient able and willing to undergo surgery. Other considerations during planning for surgical correction of the damaged urethra include (a) an autologous fascial pubovaginal sling may be considered during urethral reconstruction to help with incontinence; (b) a vascularized flap may be used in patients with history of radiation or extensive scarring to help with the poor quality of tissue and assist with healing; and (c) in patients with a small bladder capacity or low compliance, other procedures can be considered such as augmentation cystoplasty to improve vesical compliance and/or capacity.
The timing of surgery to repair fistula is variable. Historically, it was recommended to delay repair in iatrogenic fistula for 3 to 6 months to allow inflammation and edema of the local tissues to subside. This was felt to improve the quality of the tissue and render the tissue more pliable for repair. However, often this delay is not necessary, especially if physical examination reveals healthy pliable local tissues with minimal edema and inflammation. In such cases, surgical repair can be planned without the need to waiting. For obstetric fistula, where the injury is likely to be ischemic in origin, it is still preferable to wait 2 to 6 months to allow for demarcation of devitalized tissue to maximize likelihood of the success of the repair.
Alternative Therapy
Alternatives to urethral reconstruction for fistula include observation for asymptomatic individuals, or indwelling catheterization and supravesical urinary diversion for symptomatic patients. Chronic indwelling catheterization is an option especially if patients are unable or unwilling to undergo surgery. However, long-term indwelling catheterization is associated with complications such as infections, stones, detrusor dysfunction, possible urethral erosions, ostitis pubis, urothelial metaplasia, and a risk of development of squamous cell cancer. In some patients with radiation-induced urethral damage, a urinary diversion should be discussed because it may be the best long-term option.
Surgical Technique
Certain well-accepted general principles should be followed during reconstructive surgery of the urethra (
Table 37.2). Rotational vaginal wall flaps are often adequate for repair. In addition, in some cases, alternative well-vascularized pedicle flaps assist with healing and prevent recurrent fistula formation especially with extensive scarring or history of radiation therapy. The available sites for flap harvest include the labia majora (
6), the rectus abdominis muscle (
7), gracilis myocutaneous (
8), or perineal artery axial fasciocutaneous (Singapore) flaps (
9).
For reconstruction, the patient is placed in the dorsal lithotomy position and then cystourethroscopy is performed to identify the location and extent of the damage. If the fistula is high and close to the trigone, then the ureteral orifices are visualized and the ureters may be catheterized to help with identification during surgery. If a suprapubic tube placement is planned, then the site is marked and a suprapubic cystostomy tube is placed under direct visualization unless concurrent abdominal incision is anticipated in which case the suprapubic tube is placed as part of the abdominal procedure.
The choice of surgery is variable and depends on (a) the location and size of the defect and (b) the availability of local tissue for flaps (
10).
Small urethral defects: A tension-free
primary closure (
Fig. 37.1) is often adequate for small urethral defects. A 14Fr or 16Fr urethral catheter is placed, and the balloon is inflated. The vaginal wall around the fistula is marked and then hydrodissected using sterile saline. The vaginal wall around the fistula is dissected to mobilize a vaginal flap to help with closure (alternatively an inverted U-shaped incision is used). Then the periurethral fascia is dissected and mobilized to expose the urethra. The urethra is closed primarily with interrupted 4-0 or 5-0 absorbable sutures. It is often not necessary to excise the epithelium of the fistulous wall because such tissue can often be mobilized and used as a first layer of closure. This avoids increasing the size of the fistula. The periurethral fascia is then closed over the repair in a perpendicular direction to minimize overlapping of the suture lines. The vaginal wall is then advanced beyond the fistula repair and secured with absorbable sutures ensuring a lack of overlapping suture lines.
Obliterated distal urethral tissue: A U-shaped
advancement anterior vaginal flap (
Fig. 37.2) is used if the distal urethral is obliterated and no sufficient urethral tissue exists for primary closure. Bilateral parallel incisions are made on the vaginal wall distal to the proximal urethra to the site of the urethral meatus. A flap is dissected of the anterior vaginal wall, advanced, and rotated 180 degrees and is sutured to the incisions on the distal vaginal wall to form the posterior and lateral walls of the neourethra. The urethra is closed over a 14Fr urethral catheter using 4-0 or 5-0 absorbable sutures. The vaginal wall is then advanced and closed primarily.
Extensive loss of urethral tissue: A vaginal wall flap can be employed, as a
tube flap (
Fig. 37.3), as another available option in the setting of extensive loss of urethral tissue. A wide rectangular area (about 2.5 cm × 3.5 cm) is marked on the vaginal wall at the location of the distal urethra. Incisions are made and then the rectangular vaginal wall flap is mobilized and fashioned into a tube over a 14Fr urethral catheter using 4-0 or 5-0 absorbable sutures. The tube is then connected to the proximal urethra and to the site of urethral meatus using 3-0 absorbable sutures. In this situation, a pubovaginal sling is often used to achieve continence. A rotational flap of the vaginal wall is then mobilized to close the gap of the vaginal wall.
Extensive urethral damage and insufficient vaginal wall: A
labia minora pedicle flap (
Fig. 37.4) is best suited for patients with this problem. A rectangular flap 3 cm × 3.5 cm is marked on the labium and then it is incised close to the site of the urethral reconstruction and mobilized. A tunnel is created under the vaginal wall and the labium flap is then mobilized with its vascular pedicle and underlying fat and is passed beneath the vaginal wall to the site of the urethra. The flap is then fashioned around a 14Fr catheter in a tension-free manner so that the mucosal surface is facing inward to form the lumen of the future urethra. The vaginal wall is then closed. A Penrose drain is placed in the labial harvest site for 24 hours and the labial skin is closed with 3-0 absorbable sutures. The Foley catheter is left to gravity for 10 to 14 days.
Extensive urethral damage and extensive vaginal wall scarring: An anterior bladder flap can be used as an alternative to a vaginal wall flap in case of extensive vaginal scarring and vaginal wall loss secondary to a large urethrovaginal fistula that precludes using vaginal flaps. However, in this case, a concomitant anti-incontinence procedure should be strongly considered (
6) (
Fig. 37.5).
The edges of the fistula are freed by sharp dissection from the pubic rami. Next, the bladder is freed anteriorly and inferiorly from its attachments. A 4 cm × 2.5 cm rectangular flap is mobilized from the anterior bladder wall and fashioned into a tube around a 14Fr catheter using 4-0 or 5-0 absorbable sutures. The distal end of the tube is then fixed to the site of the new urethral opening in the original site. The neourethra is then fixed to the subcutaneous tissue or the periosteum of the pubic bone. A Martius flap can be performed to separate the overlapping suture lines (
6).