Vaginal Repair of Vesicovaginal Fistula

There are numerous causes for the formation of a fistula tract between the bladder and the vagina. In developing countries the primary etiology is prolonged and obstructed labor, but in more developed countries the cause of approximately 90% of vesicovaginal fistula (VVF) is surgical trauma following gynecologic procedures. Total abdominal hysterectomy for benign disease accounts for the majority offistulae secondary to gynecologic surgery. Common nonsurgical causes include advanced local carcinoma (cervical, vaginal, endometrial) and radiation therapy. Risk factors for VVF formation include prior uterine surgery (Cesarean section), endometriosis, infection, diabetes, arteriosclerosis, pelvic inflammatory disease, and prior radiation therapy.

As the primary cause of vesicovaginal fistulae is iatrogenic, prevention should always be the surgeon’s chief goal. Bladder injuries during hysterectomy are 3 times more common with an abdominal versus a vaginal approach.8 Such injuries can often be avoided with sharp dissection in the appropriate plane and the use of an indwelling catheter during dissection. All attempts should be made to diagnose and repair suspected damage to the bladder at the time of surgical injury. The bladder may be filled to check for leakage or methylene blue or indigo carmine can be administered intravenously to identify a potential site of fistula formation. All identified sites of injury should be appropriately repaired after adequate mobilization of tissues. An important maxim with these injuries is that the first operation to repair a vesicovaginal fistula has the best chance of success.

DIAGNOSIS

The classic presentation of a VVF is continuous daytime and nighttime urinary leakage following a pelvic operation. A patient with a small fistula should still normally void a significant quantity of her urine; larger fistulae do not permit adequate collection of urine in the bladder to permit voiding. Approximately two-thirds of VVF secondary to pelvic surgery are clinically evident within 10 days following the initial injury; radiation-induced fistulae may occur as late as 20 years following therapy.

Physical examination, with the aid of a speculum, may determine the source of leakage and can help differentiate a urinary fistula from urinary incontinence of other causes. A fistula site may be identified if pelvic exam is negative by placing a Foley catheter, introducing a methylene blue–tinted solution into the bladder and inspecting the vagina for leakage. If blue-tinged leakage is not apparent and the diagnosis of VVF is in doubt, the sensitivity of this test is increased by placing a vaginal packing and ambulating the patient for a short period. If the vaginal packing remains dye-free with this maneuver, then a ureterovaginal fistula should be ruled out with the use of a clean vaginal packing and intravenous indigo carmine. A modified double dye has also been described to distinguish various vaginal fistulas. Phenazopyridine is systemically administered, blue dye is placed intravesically, and a tampon is placed. After 5 minutes the tampon is examined; an orange stain at the top is consistent with a ureterovaginal fistula, blue in the midportion suggests VVF, and blue at the tip is indicative of urethral leakage, likely due to stress incontinence.

Cystoscopy, voiding cystourethrography (VCUG), and an upper tract study should be performed in patients evaluated for a urinary fistula. During cystoscopy the fistula size, the presence of collateral fistulas, and the bladder capacity are assessed; the location of the ureteral orifices in relation to the fistula are noted; and a biopsy of the fistula is done if there is a history of previous pelvic malignancy. VCUG may demonstrate the extent of the fistula as well as associated pelvic prolapse, stress incontinence, or vesicoureteral reflux that may require concomitant repair. Finally, upper tract evaluation with intravenous pyelography or computerized tomographic urography can rule out concomitant ureteral obstruction, suggestive of a ureterovaginal fistula.

INDICATIONS FOR SURGERY

Surgical repair of a VVF is indicated when conservative measures fail. Approximately 10% of posthysterectomy fistula will close with bladder drainage and antibiotics. Greatest success with this treatment option has come with fistulas only a few millimeters in diameter. Fistulous tracts that remain open 3 weeks after adequate Foley drainage are unlikely to resolve without surgical intervention.

ALTERNATIVE THERAPY

Cystoscopy with superficial bladder fulguration of the fistula is an option in patients with small, solitary, uncomplicated fistulous tracts. If the tract is not free of infection or the vesicovaginal septum is too thin at the time of fulguration, the surgeon risks increasing the diameter of the fistula with this procedure.

An alternative to the vaginal repair of VVF is an abdominal approach. Advantages of the vaginal repair of VVF include no abdominal incision, decreased morbidity, a quicker recovery, and avoidance of bivalving of the bladder. We use the abdominal approach when there is associated intraabdominal pathology such as ureteral fistula or obstruction or the need for concomitant augmentation cystoplasty (often seen in patients with radiation cystitis).

SURGICAL TECHNIQUE

There are numerous techniques describing repair of a VVF in the literature. This section discusses the technical aspects of our vaginal approach to a single, uncomplicated VVF as well as modifications for a complicated or radiation-induced fistula. Several techniques for interposing tissue and flaps that can be incorporated into the repair are also described.

The timing of VVF repair is somewhat controversial. The classic teaching is to perform fistula repair 3 to 6 months after the initial injury to allow maximum healing and resolution of inflammatory reaction. This is especially important if the repair is to be done through an abdominal approach. However, we routinely perform our repair through a vaginal approach 2 to 3 weeks after the initial injury if conservative therapy fails (i.e., the patient remains wet with a Foley catheter in place and with adequate drainage of the bladder provided) and the patient is in good general health. Retrospective review of the results have not shown a difference when comparing early transvaginal repair with delayed abdominal and vaginal repair.9 Early repair is contraindicated in patients with infection of the vaginal cuff or pelvis, and prolonged antibiotic therapy is required before reconstruction can be attempted in these patients.

Estrogen replacement is begun immediately after a VVF is diagnosed and continued up to the surgery date. Broad-spectrum intravenous antibiotics to cover anaerobes, gram-negative bacilli, and group D enterococcus are administered preoperatively.

Vaginal Approach (Basic Technique)

Positioning/Preparation/Retraction

The patient is placed in the dorsal lithotomy position, a rectal packing is placed (to aid in identification of the rectum if peritoneal flap is to be done in conjunction with the fistula repair), and the lower abdomen and perineum are prepped and draped in the usual standard fashion. Any concomitant anti-incontinence or other vaginal surgery that is to be done simultaneous with VVF repair should be done prior to reconstruction so as not to disturb the repair once completed. A suprapubic tube is placed with the use of the Lowsley retractor through a puncture wound and ureteral catheters are cystoscopically placed if the fistula tract is close to the ureteral orifices. Single-J stents can be used for difficult repairs in an attempt to keep the bladder (and the repair) dry during the early postoperative period. Appropriate exposure is maintained with use of a posterior vaginal weighted speculum, silk labial retraction sutures, and a ring retractor with hooks.

Incision

The fistula tract is initially dilated with metal sounds until a small catheter can be inserted which can be used for retraction later during the dissection. Saline is then injected into the anterior vaginal wall surrounding the fistulous tract. An inverted J-shaped incision that circumscribes the fistula tract is made with the long end of the J extending to the apex of the vagina. The asymmetric nature of this incision allows for creation of a vaginal wall flap that can be advanced and rotated over the fistula repair. This helps avoid vaginal shortening as well as overlapping suture lines during reconstruction. If the fistula is high in the vaginal cuff the incision should be inverted, placing the base of the flap distally, facing the urethral meatus.

Creation of Vaginal Wall Flaps

The vaginal wall flaps are created by dissecting in a proximal, distal, and lateral direction away from the incision. Each flap is mobilized 2 to 4 cm from the fistulous tract, exposing the perivesical fascia. The ring of vaginal tissue where the initial incision circumscribed the fistula opening is left intact; thus, flap creation is done in healthy tissue, avoiding dissection of the actual fistulous tract. This technique facilitates dissection in proper tissue planes, avoids bleeding edges at the resected fistula tract (which may require fulguration and the possible conversion of a small fistula defect into a larger defect with use of the electrocautery), ensures that closure of the fistula is done with healthy tissue (vaginal wall flaps), and decreases the risk of potential bladder perforation. In addition, adequate mobilization of the bladder allows for easier construction of a tension-free closure.

Fistula Closure

Closure of the fistulous opening is now done. The intrafistula catheter is removed and the first layer of the repair is placed with closure of the fistula tract with interrupted 2-0 polyglycolic acid sutures placed in a transverse fashion. These sutures incorporate bladder wall and the fistulous tract itself, starting in healthy tissue approximately 2 to 3 mm away from the margin of the fistula. Inclusion of the fistulous tract in the repair (and not resecting the fistula) provides a strong anchor of supporting tissue for the first layer of the repair. The second layer of the repair is placed with interrupted 2-0 polyglycolic acid sutures. These sutures are placed to invert the previous layer by imbricating the perivesical fascia and the deep musculature of the bladder over the first layer/fistula tract. The sutures should be applied at least 3 to 5 mm from the prior suture line, free of tension, and at a right angle from the first suture line to minimize overlapping of the two lines of repair. The integrity of the repair is confirmed by filling the bladder with indigo carmine.

Advancement and Closure of Vaginal Wall Flap

The final and third layer of closure is done with the vaginal wall flaps that were previously created. The redundant, excess anterior (distal) vaginal flap is excised and the posterior (proximal) vaginal flap is advanced beyond the fistula closure. This covers the fistula site with fresh, healthy vaginal tissue, which helps avoid overlapping of suture lines. The flap is advanced at least 3 cm beyond the fistula closure  and the vaginal wall is closed with a running, locking 2-0 polyglycolic acid suture.

An antibiotic-impregnated vaginal packing is placed for 24 hours postoperatively. The urethral Foley and suprapubic catheters are left to drain for 10 to 14 days. Anticholinergics are given to decrease bladder spasms and oral antibiotics are continued until the catheters are removed. A cystogram is done prior to catheter removal to document the integrity of the repair. Sexual intercourse is avoided for 3 months postoperatively.

Adjuvant Techniques for Interposition of Tissue

The interposition of healthy tissue during reconstruction is advised when repairing fistulas that are recurrent, located high in the vaginal vault, related to previous radiotherapy, ischemic (obstetric), large, associated with a difficult or doubtful closure, and when there is poor tissue quality secondary to a lack of estrogens or atrophic vaginitis. A flap of peritoneum or a Martius graft can be used when repairing a complex VVF via a vaginal approach; these two techniques are described below. The peritoneal flap is the method we prefer and is what we have primarily used for graft interposition over the past 5 years. Other procedures include gluteal skin flaps and myocutaneous gracilis muscle flaps, which are particularly useful for postirradiation fistulas, in the presence of vaginal atrophy and when no other viable skin source is available. Any one of these techniques enhances the quality of the repair by providing an additional layer of healthy tissue during closure of a complex fistula.

Martius Graft

The Martius graft, or fibrofatty labial flap, consists of adipose tissue and is the preferential graft for fistulas involving the trigone, bladder neck, and urethra. The blood supply to the graft is provided inferiorly by the posterior labial vessels (off the internal pudendal), superiorly by the external pudendal artery, and laterally by the obturator artery. The lateral blood supply is sacrificed during mobilization of the graft; the graft may be divided at either its most superior or most inferior margin (basing the blood supply on the inferior or superior vascular pedicle, respectively), depending on where the graft will be transferred.

Following the closure of the vesical portion of the fistula, the previously placed labial retraction suture is removed on the side where the flap is to be harvested and the ring retractor repositioned to eliminate tension from the labium. A vertical incision is made over the labia majora. The borders of dissection include the labiocrural fold laterally, the labia minora, and the bulbocavernosus muscle medially and Colles’ fascia covering the urogenital diaphragm posteriorly. Graft harvest is accomplished in a lateral-to-medial fashion. Dissecting down to the adductor muscles laterally before coming around the width of the Martius graft facilitates the harvest of a thick, fatty segment for graft placement. The entire thickness of the fibrofatty flap is included in a small Penrose drain and gentle downward traction is applied to aid in dissection superiorly. The main vascular supply to the graft is located at the base of the labia majora. The anterior segment is clamped and transected interior to the pubic symphysis. The free segment of the graft is dissected from the underlying structure down to the posterior based vascular pedicle.

Dissection is carried out from the site of the repair, between the vaginal wall and the perivaginal tissue, to create a tunnel to transfer the graft to the area of the fistula. A hemostat is used to transfer the fibrofatty pad from the harvest site through the tunnel to the vaginal area. The graft is placed over the fistula repair and secured with interrupted absorbable sutures in a tension-free manner.

The vaginal wall flap is advanced over the Martius graft and closed as previously described. A small Jackson-Pratt may be left in the labial incision if the operative field is not completely dry. The labial incision is closed and a pressure dressing may be applied to the labial skin incision.

Peritoneal Flap

The use of a peritoneal flap during repair of a complex VVF is a simple procedure that does not require extravaginal harvesting of the graft as does a Martius flap. This technique is primarily used in conjunction with repair of a high-lying VVF. Following formation of the vaginal flaps, dissection of the posterior (proximal) vaginal flap is continued into the cul-de-sac. The peritoneum and preperitoneal fat is identified, isolated, and mobilized using sharp dissection.

The first two layers of the fistula are closed as described above. At this point the peritoneal flap is advanced over the fistula repair and secured with interrupted absorbable sutures in a tension-free manner. If a peritoneotomy is made the defect can be closed as the flap is secured to the perivesical fascia over the fistula repair. The vaginal flap is then advanced and closed as previously described, providing a fourth layer of closure.

Radiation-Induced Fistula

The pathologic changes that lead to formation of a VVF after radiation also result in different strategies when a radiation-induced fistula is repaired. Radiation damage leads to obliterative endarteritis and results in poorly vascularized tissue along the fistula site and the surrounding tissue. Therefore, spontaneous healing of this kind of defect is unlikely. Radiation-induced VVFs are typically found in the trigone. This area of the bladder is fixed and more susceptible to the effects of radiation.

Primary repair of a radiation-induced fistula is difficult because the surrounding tissue is often fixed, easy to slough, and nonpliable. Extensive dissection of the fistulous tract combined with augmentation cystoplasty is a successful option, especially in the bladder that is contracted from previous radiation. We prefer to use ileum for augmentation; however, virtually all segments of bowel have been used by various authors for bladder augmentation. Whatever segment is used, the bowel should be nonirradiated, minimizing any compromise to the blood supply that could lead to suture line breakdown and failure of the reconstruction. Finally, inter-position of healthy tissue (such as omentum or a Martius graft) between the repair is performed, eliminating the possibility of an overlapping suture line and decreasing the risk of recurrent fistula.

OUTCOMES

Complications

Early postoperative complications include vaginal infection, bladder spasms, and bleeding. Bladder spasms should be treated with anticholinergics and vaginal bleeding is treated with bed rest and vaginal packing.

Late complications include vaginal shortening or stenosis, unrecognized ureteral injury, and recurrence of the fistula. Excessive resection of the vaginal wall causes vaginal shortening or stenosis, and is treated with vaginoplasty. Ureteral injuries are initially managed with a percutaneous nephrostomy drainage; retrograde pyelography and ureteroscopy should be avoided in the early postoperative period as they may result in disruption of the fistula repair. Recurrent fistula may be repaired again through a vaginal approach. This should be done no sooner than 3 months after the previous repair to allow for resolution of postoperative inflammation and is often done in conjunction with adjuvant measures such as a Martius or peritoneal flap.

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