Vesicovaginal Fistula

Vesicovaginal fistulas (VVFs) have been recorded as a clinical entity since ancient times. The American surgeon Sims is commonly credited with having performed the first successful surgical repair of a VVF, as reported by him in 1852.

Vesicovaginal fistulas are extremely distressing as well as disabling to the patient. In industrialized soci-eties, VVFs occur most frequently as a result of iatrogenic injury at the time of gynecologic surgery, in particular hysterectomy. Other causes of VVFs are technically difficult surgical procedures or impaired wound healing (as a result of infection, neoplasia, previous radiation therapy, foreign bodies, or pelvic trauma) that is frequently complicated by medical conditions such as diabetes mellitus or atherosclerosis. In underdeveloped countries, especially in some parts of Africa, however, the most common cause of VVF is obstetric injury. The mechanism involved in prolonged labor is pressure necrosis of the bladder where it is caught between the obstructed head of the infant and the pubic bone.

DIAGNOSIS

The classic symptom of VVF is continuous leakage of urine per vaginam, with varying degrees of severity. This may develop immediately following the surgical procedure or be delayed, as in necrosis of the tissue or after radiation therapy, in the latter case months or even years after such treatment because of progressive obliterative endarteritis with resultant ischemia.

For diagnosis, a careful history, including the details of prior surgery, and a thorough physical examination are the usual prerequisites. An excretory urogram is advantageous in order to evaluate the upper urinary tract, particularly looking for associated ureteral injuries. The exact location and the size of the fistula and its relationship to the ureteral orifices are usually identified by cystoscopic examination. Vaginoscopy is very helpful in exactly localizing the fistula. If cystoscopy and vaginoscopy are performed at the same time, a ureteral catheter can be threaded through the fistula from the bladder into the vagina, thereby facilitating the recognition of the fistulous tract. Using both endoscopic inspections, it is important to determine the mobility of the fistulous segment of the bladder and also the degree of inflammation surrounding the fistula. In a patient with a history of prior pelvic neoplasia, a biopsy of the fistula site is mandatory to rule out recurrent tumor.

Small fistulas that may escape detection by cystoscopy or vaginoscopy can be demonstrated by the following maneuver: a gauze sponge is placed into the vagina, and methylene blue or indigo carmine is instilled into the bladder. In case a fistula is present, the tampon will turn blue. Blue coloring after intravenous administration of indigo carmine is not necessarily diagnostic for the presence of a VVF because with this maneuver the leakage can also be induced by a ureterovaginal fistula.

INDICATIONS FOR SURGERY

The successful laparoscopic repair of VVF was reported recently. The vast majority of VVFs, however, need repair by a surgical method, either transvaginally or by the suprapubic route. The choice of surgical approach is subject to the personal inclination of the urologist. Provided sound surgical principles are adhered to, i.e., complete excision of diseased tissue and reconstruction of the bladder using healthy, well-vascularized tissues, any surgical repair will succeed.

Controversy still remains concerning the timing of fistula repair. Among patients with VVF there is quite understandably a strong desire for an expedient repair. The conventional wisdom, however, is to delay surgical intervention for 3 to 4 months. When ischemic necrosis complicated by inflammatory reaction of the tissue gives rise to the defect, delayed repair is obligatory. In clean iatrogenic injuries, e.g., in the course of hysterectomy, however, there is no disadvantage in early repair, i.e., as soon as possible after the fistula is discovered.

ALTERNATIVE THERAPY

A variety of treatment options exist for the closure of a VVF. In fistulas of very small caliber it may be worthwhile to attempt a conservative approach. This can be done by curettage or cauterization of the fistulous tract or by application of silver nitrate as well as by simple drainage of the bladder via a transurethral catheter for a prolonged period of time. Such a conservative trial would certainly not prejudice future surgery and seems indicated in cases where delayed repair of the VVF is contemplated.

There are several reports of successful closure of a VVF by introducing a fibrin clot into the fistula either cystoscopically or transvaginally or both ways.

SURGICAL TECHNIQUE

Successful treatment of VVF depends largely on careful preparation of the patient and on the ability of the urologist to vary the operative technique according to the requirements of each individual patient and to perform the technical details with meticulous precision.

Transvaginal Repair

Generally, the transvaginal approach to repair a VVF is simpler and less disturbing to the patient. The majority of patients with VVF can be treated by the vaginal route. Indications for using this approach are as follows:

  • Fistulas less than 3 to 4 cm in diameter
  • Tissues pliable
  • Vaginal size normal or larger than normal
  • No cancerous tissue involved
  • No previous extensive radiotherapy

The advantages of the transvaginal approach include:

  • Avoidance of an abdominal incision
  • Minimal blood loss
  • Reduced postoperative morbidity
  • Less postoperative discomfort to the patient
  • Decreased length of hospitalization

A disadvantage of performing the transvaginal procedure is the relative lack of familiarity with the surgical anatomy of this region by many urologists.

Before repair, cystoscopy is carried out to confirm the position of the VVF and its relation to the ureteral orifices. Bilateral ureteral catheters are inserted, irrespective of the position of the fistulous tract. If possible, a ureteral catheter is introduced through the fistula into the vagina. After the removal of the cystoscope, an 18-Fr Foley catheter is inserted transurethrally, and the three previously mentioned ureteral catheters are tied to it just outside of the urethral meatus. Then the patient is placed in the hyperflexed dorsal lithotomy position. A weighted vaginal speculum is inserted, and the labia minora are sutured to the inner thighs in order to obtain good exposure. A small Foley catheter is placed through the fistula into the bladder. In small fistulas the cystoscopically introduced ureteral catheter can be used advantageously in pulling the tip of the Foley catheter tied to its tip into the bladder. After its balloon has been inflated, traction can be applied to the catheter, which provides an additional means for exposure.

The vaginal mucosa is incised circumferentially around the opening of the fistula, and the cicatricial or necrotic tissue of the fistulous tract is excised to the margin of fresh, healthy tissue after removal of the catheter. The defect is closed in three layers. The first layer, utilizing 3-0 polyglactin or polyglycolic acid sutures, ties the submucosa of the bladder thus approximating the mucosa without injuring it. The second layer, using the same suture type, ties the muscularis and the adventitia of the bladder. The third layer, utilizing 2-0 or 0 polyglactin or polyglycolic acid sutures, knits the vaginal mucosa. It is advisable to close successive layers in perpendicular directions, i.e., vertically versus transversely, in order to avoid overlapping suture lines. When difficulties arise, sutures with a 5/8; needle can be of advantage. Although no drain is used, a tampon is placed into the vagina and extracted on the second postoperative day. The ureteral catheters are left in place and connected to urine-collecting bags. They are withdrawn on the third postoperative day. The Foley catheter is removed 7 to 10 days after surgery. Alternatively, a suprapubic tube can be utilized. Uninterrupted catheter drainage during this time is of utmost importance. Antibiotics are given as long as the urethral or the suprapubic catheter is in place. The patient is instructed to abstain from intercourse for approximately 2 months.

If the tissue to be closed is tenuous, or if the transvaginal repair is difficult, a vascularized fibrofatty labial segment can be utilized for interposition between bladder and vagina. This segment, called the Martius flap,3 is easy to harvest because of its convenient location. Through a separate incision in the lateral aspect of the labia majora the underlying fat pad is mobilized and then pulled through a subcutaneous tunnel into the vaginal incision. There it is interposed between bladder and vagina with absorbable sutures.

Suprapubic Approach

Indications for a suprapubic approach include:

Associated pelvic pathology

Cases where ureteral reimplantation may be required

Limited access because of a high retracted fistula in a narrow vagina

Some cases with multiple fistulous tracts

Complications related to previous irradiation

The confirmation of the location of the fistula by cystoscopic examination is the same as when the transvaginal approach is used. The patient is placed in a supine position, and a lower midline incision is made. The perivesical space is mobilized, and the peritoneum is retracted cephalad from the dome of the bladder. The bladder is opened by a longitudinal midline incision and then split posteriorly and downward toward the fistula. The ureters may be catheterized if desired. The fistulous tract is excised all the way into the vagina. The opening of the vagina is closed with interrupted 2-0 absorbable sutures (Vicryl or Dexon) in one or two layers. In uncomplicated cases the bladder is then closed in two layers with continuous sutures of the same material. It is important to mobilize the vagina as well as the bladder flaps widely in order to avoid any tension on the suture lines.

In previously irradiated tissue or in complicated cases, instead of simple closure of the vagina and the bladder, it is safer to use interposition of an omental graft in order to prevent recurrent fistula formation.

The blood supply of the omentum from the left gastroepiploic artery and branches of the splenic artery, and from the right gastroepiploic artery and the gastroduodenal artery, can be observed by transillumination. This dual blood supply permits mobilization of the omentum from the greater curvature of the stomach. In some cases it is possible to extend the lower margin of the omentum down to the fistula without mobilization of the omentum from above. In most cases, however, is has to be dissected from the transverse colon. Either the left or the right gastroepiploic artery is divided between 3-0 silk ligatures close to the stomach until a well-vascularized omental flap is created, long enough to be brought down to the pelvis without tension. The omental apron is transferred to the pelvis extraperitoneally, dorsal to the ascending colon. A portion of the flap is interposed between anterior vaginal wall and posterior bladder wall and tacked in position with absorbable sutures. The omentum must extend well beyond the margins of the repairs.

Either a urethral catheter or a cystotomy tube can be used for bladder drainage. If ureteral catheters had been inserted, they should be left in place to keep the wound free of urinary drainage. Retrovesical drains are placed, and then the incision is closed in the usual fashion. The ureteral catheters and the drains are removed around the fifth postoperative day. The removal of the suprapubic tube or the urethral catheter takes place 2 weeks postoperatively.

For interposition between bladder and vagina, a peritoneal flap can be used instead of omentum. It is usually readily available. In large fistulas, however, particularly in radiogenic ones, a pedicled omental apron is the optimal tissue. In a small, uncomplicated VVF a simple closure in layers, as described previously, will usually suffice without the necessity of resorting to the use of peritoneum.

OUTCOMES

Complications

Most authors agree that the vast majority of VVFs can be successfully repaired transvaginally. It is of particular advantage that the complication rate is definitely less when this route is used rather than the suprapubic, transabdominal approach.

The complication of most concern is a recurrent urine leak. One can try to manage it by reinserting a catheter in order to drain the bladder for 3 or 4 weeks. If this fails to close the fistula, a new attempt at reconstruction is inevitable. Reasons for failed repair are insufficient debridement of nonviable and scar tissue before closure, excessive tension on the suture lines, inadequate closure of dead space, postoperative bladder distension, e.g., because of a plugged catheter, abscess formation, and poor tissue healing as a result of persistent or recurrent neoplasia or radiation-induced damage.

After an abdominal approach, it is not uncommon to encounter a significant period of ileus, particularly following extensive omental mobilization. Delayed healing and wound infections occur more frequently after transabdominal fistula repair than following the transvaginal procedure. Bowel obstruction secondary to adhesions is a typical, if infrequent, complication of the transabdominal procedure. It is not seen when the transvaginal method is used.

Results

At the author’s institution, 64 vesicovaginal fistulas were treated during the 30-year period between 1966 and August 1996. The 64 VVFs were caused by abdominal hysterectomy in 42 cases, vaginal hysterectomy in 12, radiation therapy in seven, obstetric complications in two, and colporrhaphy in one patient. In 60 patients (94%), the transvaginal approach was used; in four patients the transabdominal route (6%). Fourteen of the 60 patients had had prior attempts to repair the VVF. Of these 14 patients, six had undergone a transabdominal attempt, five a transvaginal procedure, and three a combined transvaginal and transabdominal surgery. In 55 of the 60 transvaginally repaired VVFs (92%), the primary closure was successful. In five patients (8%), a secondary transvaginal procedure became necessary for a successful closure.

The vast majority of vesicovaginal fistulas can be closed with a proper surgical approach and meticulous attention to detail by the urologist. In those few unfortunate patients in whom every attempt fails to successfully repair the fistula—which is usually the result of irradiation—urinary diversion can become necessary as a last resort to improve their quality of life.

Advertisements

2 Responses to Vesicovaginal Fistula

  1. Pingback: Vesicoenteric Fistula « Urology Surgery

  2. Pingback: VESICAL TRAUMA « Urology Surgery

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: