Rectovaginal Fistula Treatment & Management

Use local care, drainage of abscesses, and directed antibiotic therapy to treat acute rectovaginal fistulas (RVFs) of traumatic origin (including those caused by obstetric^{[2, 3]} and operative trauma), RVFs complicated by secondary infection, and fistulas of infectious origin. Allow tissues to heal for 6-12 weeks. Dietary modification and supplemental fiber can greatly diminish symptoms during this period. Many fistulas resulting from obstetric or operative trauma heal completely, requiring no further therapy. When the fistula persists after this period of treatment and the tissues become uninflamed and supple, repair may be considered.

Perform a biopsy on any area suggestive of neoplasm. Treat neoplasms as appropriate. In this setting, very symptomatic fistulas may prompt the physician and patient to consider a diverting colostomy for patient comfort. Otherwise, fecal diversion is rarely used with RVFs.^[1]

If the evaluation is consistent with the diagnosis of IBD, institute appropriate medical therapy. Repair of an RVF can be performed while the patient is on steroids, with the understanding that the risk of failure is increased. Even after initial failed repair attempts, some patients with Crohn disease can maintain RVF repair while on antimetabolites, such as 6-mercaptopurine or azathioprine (Imuran). Clinical use of infliximab (Remicade)^[7] suggests that few fistulas heal completely, but most patients are dramatically improved symptomatically. Predictors of failure requiring fecal diversion have been identified and include significant colonic involvement and the presence of anal stricture.^[1] The development of carcinoma has been described in Crohn fistulas.^[8]

RVFs originating from radiation therapy are very difficult to treat surgically,^[4] and medical therapy is often initially recommended in this setting. Diet and fiber are the mainstays of therapy.

See Intraoperative Details.

Complete mechanical bowel preparation is essential for the transabdominal repair of rectovaginal fistula (RVF) and is also recommended for local repairs. The practice of including poorly absorbed oral antibiotics in the bowel preparation is under scrutiny. New data suggest that intravenous antibiotics administered in a manner that provides appropriate tissue levels at the beginning of the operative procedure are sufficient for prophylaxis. The author recommends that prophylactic intravenous antibiotics be administered preoperatively for all patients undergoing RVF repairs, transabdominal or local.

Although diverting colostomy was used in the past, the overwhelming majority of RVFs are now repaired without this procedure being performed beforehand.

Cleanse the vaginal lumen with an antiseptic solution, such as Betadine. Insert a catheter into the urinary bladder.

If a transabdominal procedure is planned, perform standard preoperative cardiopulmonary evaluation as appropriate. Prophylaxis against venous thromboembolism is essential and may include the use of fractionated or unfractionated heparin, as well as the employment of sequential compression devices. If the pelvis has been irradiated or previously operated upon, the use of ureteral catheters may aid in dissection. A laparoscopic approach has been described.^[9]

Local repair methods

Transanal advancement flap repair^[10]

The best results have been reported with this type of repair. General, regional, or local anesthesia may be used. The patient is placed in the prone, flexed position with a hip roll in place; the buttocks are taped apart for exposure. The fistula is identified using the operating anoscope. A flap is outlined, extending at least 4 cm cephalad to the fistula, with the base of the flap twice the width of the apex to allow adequate blood supply to the flap tip. Local anesthetic with epinephrine is injected submucosally to facilitate raising the flap and to diminish bleeding.

The flap, consisting of mucosa and submucosa, is raised; some surgeons include circular muscle as well. Meticulous hemostasis is imperative. The fistula tract is curetted gently. Circular muscle is closed over the fistula. The tip of the flap, which includes the fistula opening, is excised. The flap is sutured in place with simple interrupted, absorbable sutures, effectively closing the rectal opening of the fistula. The vaginal side of the fistula is left open for drainage. This approach separates the suture line from the fistula site and interposes healthy muscle between the rectal and vaginal walls. Proponents point out that the relatively high pressure within the rectum serves to buttress the repair, in contrast to a transvaginal repair, in which the intrarectal pressure is more prone to disrupt the repair. If indicated, sphincteroplasty can be performed concomitantly.^[11]

Transvaginal inversion repair

The vaginal mucosa is circumferentially elevated, exposing the fistula. Two or 3 concentric pursestring sutures are used to invert the fistula into the rectal lumen. The vaginal mucosa is reapproximated. This approach is suitable only for small, low fistulas in otherwise healthy tissues with an intact perineal body. It is rarely performed today.

Bioprosthetic repair

Bioprosthetic interposition graft is placed by making a transverse incision over the midportion of the perineal body with dissection through the subcutaneous tissue. The fistula tract is transected. The dissection is continued 2 cm proximal to the transected fistula tract and laterally. The fistula openings are closed with 3/0 interrupted, absorbable sutures. The graft needs an overlap of 2 cm on all sides of the rectal and vaginal mucosal closures. A bioprosthetic plug is placed through the rectal opening and out the vaginal opening. The excess plug is trimmed and secured on the rectal side with 2/0 absorbable suture.

Conversion to complete perineal laceration with layer closure^[10]

The fistulous tract is laid open in the midline, essentially creating a cloaca. Closure in layers follows, identical to the classic obstetric repair of a fourth-degree perineal laceration. This method is described in the gynecologic literature; it is rarely employed by colorectal surgeons because of concerns of juxtaposed suture lines.

Simple fistulotomy

This procedure works well for true anovaginal fistulas, in which no sphincter is involved in the tract. If the technique is used to treat an RVF, however, partial or total fecal incontinence results.

Transabdominal approaches

Transabdominal approaches are generally used for high RVFs when the fistula originates from a neoplasm, from radiation, or, occasionally, from IBD. They are also used if concomitant disease (eg, diverticulitis) warrants an abdominal approach.

Fistula division and closure without bowel resection

This is the simplest abdominal approach. The rectovaginal septum is dissected, the fistula is divided, and the rectum and vagina are closed primarily without bowel resection. Interposition of healthy tissue, such as omentum, may be used to buttress the repair and separate the suture lines. Good results have been reported when the fistula is not large and the tissues available for closure are healthy.

Bowel resection

When tissues are abnormal because of irradiation, inflammation, or neoplasm, the repair is doomed to failure unless the abnormal tissues are resected. Preserve functional anal sphincters whenever possible by use of a low anterior resection, a coloanal anastomosis technique, or a pull-through; the last alternative has the poorest results with respect to continence. Rarely, abdominoperineal resection may be necessary for symptom control in the setting of radiation damage or neoplasm. An alternative, particularly in cases of poor operative risks or with patients whose survival is limited, is simple fecal diversion with a loop ileostomy or colostomy.

Ancillary procedures

A host of supplementary procedures have been described to augment bowel resection in the difficult pelvis. These include local flaps, such as the bulbocavernosus flap, and a variety of muscle, fascial, and musculocutaneous flaps for repair of large pelvic defects. A variety of graft procedures also have been described.^[12] All of these procedures have the goal of interposing healthy tissue between vaginal and rectal repairs. These are well described in the plastic surgery literature.

Local repairs

Pay attention to the patient's bowel habits. Constipation or diarrhea can disrupt a repair. The goal is a soft, formed, deformable stool. The patient is carefully counseled regarding diet, copious fluid intake, and the use of stool softeners. The use of bulking agents immediately after repair is at the discretion of the surgeon and is a matter of individual preference rather than of scientifically proven practice. The use of oral antibiotics also varies. The author prefers that patients use an oral broad-spectrum antibiotic for 3-5 days postoperatively, take 1 tablespoon of mineral oil orally twice daily for 2 weeks postoperatively, and avoid bulking agents for 2 weeks postoperatively. The patients need to refrain from sexual activity or any physical activity more strenuous than a slow walk for 3 weeks.

Abdominal repairs

Postoperative care is identical to the care administered to all patients who have undergone major laparotomy with bowel resection and anastomosis. Postoperative gastric decompression is performed selectively, expecting that 15-20% of patients require cessation of oral intake or gastric decompression for symptomatic postoperative ileus. Most patients can be offered sips of clear liquids on the first postoperative day. Early ambulation is beneficial in many ways. Continue perioperative prophylaxis for thromboembolic events until the patient is ambulating well.

Patients are seen 2 weeks after discharge for evaluation of wounds and bowel habits. In the absence of recurrent fistula symptoms or other specific indications, no follow-up investigation, aside from physical examination, is required. Specific signs and symptoms are investigated appropriately. For example, fever, diarrhea, and low abdominal pain indicating an abscess are evaluated by a CT scan of the abdomen and pelvis. In this setting, physical examination may be difficult because of patient discomfort.

Complications of local repairs

Bleeding is rarely encountered postoperatively, probably because of careful intraoperative hemostasis. If bleeding occurs beneath the flap, fistula recurrence is common. Infection is a feared complication, because it almost invariably results in a failed repair. However, good data on the incidence of infection after local repair are few. Of course, repairs may fail in the absence of infection as well (see Outcome and Prognosis). Rarely, postoperative pain precipitates urinary retention.

Complications of transabdominal repairs

These may include the usual complications of any laparotomy with bowel resection, including fistula recurrence. The most common complications are bleeding and wound infection, each with an incidence of less than 2-5% in reasonable-risk candidates. Pelvic abscess occurs in 5-7% of patients. Data from the United States and Europe suggest that anastomotic leaks occur more often than is clinically recognized. However, because intervention is indicated only in clinically evident leaks, routine postoperative anastomotic evaluation is not warranted.

Local repair methods

Transanal advancement flap repair

This approach to rectovaginal fistula (RVF) repair is very safe. Results are good to excellent, with success reported in 77-100% of patients in various series. Reports have noted the importance of preoperative assessment of anal sphincter integrity. Sphincter repair is easily performed simultaneously and increases the success rate of RVF repair. Vaginal childbirth after RVF repair is not associated with increased risk of RVF recurrence. However, if a sphincter repair is performed along with the RVF repair, many surgeons recommend cesarean delivery for subsequent pregnancies in order to avoid disruption of the sphincteroplasty.

Transvaginal inversion repair and conversion to complete perineal laceration with layer closure

Results from these approaches can be acceptable in selected cases, as noted above (see Intraoperative Details).

Bioprosthetic repair

This is a new technique for RVF repair. Early experience indicates that it produces results that are equal or superior to those of advancement flap repair.^[13] The new button fistula plug has been successful in 58% of rectovaginal and ileal pouch-vaginal fistulas.^[14]

Simple fistulotomy

As noted, this is suitable for true anovaginal fistulas only, which incorporate no sphincter muscle whatsoever. Application of this approach to RVF results in incontinence.

Transabdominal approaches

With approximation of healthy tissue in the absence of inflammation, infection, or tension, transabdominal repairs yield good long-term results. Always consider the morbidities of major abdominal surgery and any coexistent morbidities related to the patient's history.

Patients with fistulas due to radiation may have added morbidities associated with other irradiated tissues. These morbidities include (1) cystitis; (2) ureteral complications, including stricture and obstruction; (3) vascular injury, including stenosis and occlusion; (4) small bowel injury, including stricture, malabsorption, and obstruction; (5) neurologic complications; and (6) bony complications, including necrosis and fractures.

Prognosis of recurrent RVFs

Recurrence of an RVF confers a poorer prognosis for future repair attempts.^[15] Rectal sleeve advancement had an overall healing rate of 75% for persistent rectovaginal fistulas.^[16] Recurrence is influenced by the etiology of the fistula and by its complexity. Fistulas of obstetric origin and fistulas that are considered simple (rather than complex) fare better after repeated repair attempts.

Crohn disease

Rectovaginal fistulas (RVFs) associated with Crohn disease are difficult to manage.^{[5, 17]} When symptoms are few, operative intervention may not be indicated. Conversely, severely symptomatic patients may require proctectomy. Patients with relatively normal rectal mucosa and an RVF are good candidates for an endorectal advancement flap. In this specific setting, outcome is good, although it is not as good as in patients without Crohn disease. An endorectal advancement flap is considered the preferred technique for local RVF repair in patients with Crohn disease and a relatively normal rectum. A multivariable logistic regression model identified immunomodulators as being associated with successful healing and smoking and steroid usage as being associated with failure.^[18]

Bricker patch

The on-lay Bricker patch also has been used to repair RVFs, chiefly those produced by radiation. Briefly summarized, the rectosigmoid colon is mobilized transabdominally, and the RVF is exposed. The rectosigmoid is divided above the fistula. The proximal end is brought out as an end sigmoid colostomy. The distal rectosigmoid is turned down, and the open end is anastomosed to the debrided edge of the rectal opening of the fistula, essentially creating an internal loop with drainage through the anus. When healing of the inferior-patched rectum can be demonstrated radiologically several months later, continuity of the colon is reestablished by anastomosis of the colostomy to the apex of the patch loop in an end-to-side fashion.

Advantages to this procedure may include less difficulty than with resection approaches; therefore, less morbidity of hemorrhage and organ injury occurs. Disadvantages include the radiation-damaged rectum being left in place and in use, with the possibility of further morbidity, including bleeding and stricture.

Although situations exist in which this approach may be preferable to a resection approach, the author believes that resection of the radiation-damaged bowel provides the best long-term results in patients who are reasonable operative candidates.