Female Urethral Reconstruction for Fistula and Female Urethral Diverticulum
Female Urethral Reconstruction for Fistula and Female Urethral Diverticulum
AHMED M. EL-ZAWAHRY
ERIC S. ROVNER
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).
TABLE 37.1 CAUSES OF URETHRAL DAMAGE IN A CASE SERIES OF 74 WOMEN
Urethral diverticulectomy or diverticulum
Urethral injury from Pereyra procedure
Fistula from other gynecologic surgery
Fistula or erosion associated with synthetic material
In patients with urethrovaginal fistula, presentation depends on the location of the fistula. Distal urethrovaginal fistula may be asymptomatic, or the patient may present with vaginal voiding or splitting and spraying of urinary stream. Urethrovaginal fistula proximal to the sphincter can present with urinary incontinence.
A thorough history and physical examination are critical for evaluating a patient with suspected urethral fistula. The causes of the urethral problems need to be identified because it may impact the choice of surgery. Proper pelvic examination using suitable light and a speculum is important to identify the site of injuries or fistula, size, proximity to the bladder neck and urethral sphincter, and ureters. Any concomitant and adjacent injuries should be identified. The vaginal walls should be properly inspected for urine leak, and the quality of adjacent local tissue and the vaginal wall that could be used for reconstruction should be assessed.
Cystoscopy should be considered to help identify the location of the fistula relative to the bladder neck and sphincter and the extent of the pathology. If there is difficulty in identifying the fistula, vital dye such as indigo carmine diluted in saline could be used during cystoscopy or infused through a partially inflated Foley catheter in order to localize the fistula. Cystoscopy may also help to rule out the presence of any other concomitant pathology.
Radiographic imaging may be helpful to assess the integrity of the rest of the urinary tract. Abdominal and pelvic computerized tomography with intravenous contrast can help to identify concomitant injuries. Cystogram and voiding cystourethrogram (VCUG) may be helpful if bladder injury is suspected or to further identify the location of the fistula or the length of associated urethral stricture. Retrograde pyelography or other upper tract imaging can be performed when ureteral injury is suspected (2,5).
Videourodynamic (VUD) examination should be considered in patients with coexisting lower urinary tract symptoms or symptoms suggestive of bladder neck injury. VUD helps to diagnose problems with bladder function such as the presence detrusor overactivity, abnormal bladder compliance, bladder capacity, bladder outlet obstruction, ureteral reflux, and urethral stricture and can identify concurrent vesical fistulas or diverticula.
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.
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.
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).
TABLE 37.2 GENERAL PRINCIPLES OF URETHRAL RECONSTRUCTION
Use multiple layers for closure.
Avoid overlapping suture lines.
Good mobilization of the anterior vaginal wall flap
Appropriate postoperative drainage; some advocate using a suprapubic tubes and urethral catheters.
May consider postoperative antimuscarinics for bladder spasms
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).
FIGURE 37.1 Primary closure. A: The fistula is circumscribed. B: Hydrodissection and then the lateral vaginal wall flaps are developed, and the lateral urethral walls are mobilized and freed. C: The urethra is closed primarily with interrupted tension-free watertight 4-0 or 5-0 absorbable sutures around a 14Fr catheter. D: The vaginal wall is closed primarily if possible or through mobilizing a U-shaped flap trying to avoid overlapping suture lines. (Modified from Mattingly RF, Thompson JD, eds. Telinde’s Operative Gynecology, 6th ed. Philadelphia: JB Lippincott Co, 1985:662.)
FIGURE 37.2 Advancement flap. A: A U-shaped incision is made with the arms of the U extending caudally as far as the planned urethral meatus. B: The flap is elevated and rotated 180 degrees. C: The flap is sutured to the edges of the parallel distal incisions over the catheter to form the new urethra. D: The vaginal wall is closed either primarily or with a U-shaped flap, depending on the availability of local tissue. (Modified from Mattingly RF, Thompson JD, eds. Telinde’s Operative Gynecology, 6th ed. Philadelphia: JB Lippincott Co, 1985:660-661.)
FIGURE 37.3 Tube graft. A: Hydrodissection of the vaginal wall and then an inverted U-shaped incision is made in the anterior vaginal wall with the apex of the U at the vesical neck just proximal to the urethral fistula. The fistula is circumscribed. B: A plane is created in the avascular plane just underneath the vaginal skin, and the vaginal wall flap is developed and reflected posteriorly. If a pubovaginal sling is to be performed, the dissection into the retropubic space is completed at this time. C: The urethrovaginal fistula is closed with interrupted sutures of 3-0 or 4-0 absorbable sutures. D: Two parallel incisions are made alongside the Foley catheter to the site of the neourethra meatus and medially based flaps are elevated and sutured in the midline creating a tube graft around the catheter. E: The vaginal and labial wounds are closed. (From Blavais JG. Vaginal flap urethral reconstruction. An alternative to the bladder flap neurourethra. J Urol 1989;41:542-545, with permission.)
FIGURE 37.4 Labia minora pedicle graft. A: A rectangular incision 3.5 cm × 2.5 cm in the labia minora after hydrodissection is made and then the labial tissue and underlying fat is mobilized on the vascular pedicle. B: The flap is passed through a tunnel created under the wall of the labial skin to the site of the neourethra and sutured into position with the mucosal surface of the labia becoming the lumen of the neourethra.
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).
FIGURE 37.6 Pubovaginal sling. A: A lower abdominal Pfannenstiel incision is made at the skin crease, and dissection is carried out to the level of the rectus fascia. A 2 to 3 cm wide and 8 cm to 10 cm in length graft is outlined with the incision kept parallel to the direction of the fascial fibers. B: A 2-0 nonabsorbable running horizontal mattress suture is placed across the most lateral portion of the graft, and the ends are left long. C: Each end of the fascial graft is transected approximately 1 cm lateral to the mattress suture. D: Transvaginally, dissection is begun with Metzenbaum scissors in the avascular plane just beneath the vaginal skin. E: The endopelvic fascia is perforated with Mayo scissors with the tips of the scissors directed toward the patient’s ipsilateral shoulder and ensure the tip of the scissors are marching on the posterior aspect of the pubic bone until the retropubic space is entered. F: A Pereyra-Raz ligature carrier or a long tonsil clamp is passed from the abdominal to the vaginal wound lateral to the urethra while protecting the urethra with a finger to bring one end of the graft to the abdominal incision. G: The fascial graft is passed around the urethra and brought to the abdominal wound. H: The long ends of the sling are tied together in the midline under no tension. The labial fat pad, if used, is positioned between the sling and the vesical neck. (A-G from Blavais JG. Pubovaginal sling procedure. In: Whitehead ED, ed. Current Operative Urology. Philadelphia: JB Lippincott Co, 1990:93-101, with permission.)