Approach Considerations
Because the symptoms of rectovaginal fistula (RVF) are so distressing, surgical therapy is almost always indicated. Exceptions include patients who are moribund and those for whom the proposed anesthesia and surgery pose prohibitive risks. Note that surgical therapy means repair in most cases; however, some patients are better served by a diverting stoma than by an ill-advised repair attempt. Although repair commonly yields good rates of closure and patient satisfaction, even permanent fistula closure is not necessarily free of postoperative problems. [18]
Guidelines for management of RVF have been developed by the American Society of Colon and Rectal Surgeons (ASCRS; see Guidelines). [19]
Medical Therapy
Use local care, drainage of abscesses, and directed antibiotic therapy to treat acute RVFs of traumatic origin (including those caused by obstetric [8, 9] 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, highly symptomatic fistulas may prompt the physician and patient to consider a diverting colostomy for patient comfort. Otherwise, fecal diversion is rarely used with RVFs. [3]
If the evaluation is consistent with the diagnosis of inflammatory bowel disease (IBD), institute appropriate medical therapy. Repair of an RVF can be performed while the patient is on steroid therapy, 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. Clinical use of infliximab [20, 21] suggests that few fistulas heal completely, but most patients experience dramatic improvements in their symptoms.
Predictors of failure necessitating fecal diversion have been identified and include significant colonic involvement and the presence of anal stricture. [3] The development of carcinoma has been described in Crohn fistulas. [22]
RVFs originating from radiation therapy are very difficult to treat surgically, [6] and medical therapy is often initially recommended in this setting. Diet and fiber are the mainstays of treatment.
Surgical Therapy
Surgical treatment is almost always indicated. Typically, such treatment consists of repair via either a local or a transabdominal approach (see below).
Minimally invasive approaches have been described. [23] Mukwege et al applied a laparoscopic approach to the treatment of high RVFs in 10 patients and reported a clinical success rate of 90% (median follow-up, 14.3 months). [24] Lamazza et al used endoscopic placement of a self-expanding metal stent to treat 10 patients with RVF after colorectal resection for cancer. At follow-up (mean, 24 months), eight RVFs had healed without major fecal incontinence; the other two had been reduced sufficiently to allow a flap transposition. [25] Yuan et al retrospective reviewed 17 patients who underwent transanal endoscopic repair of mid-low rectovaginal fistulas. [26]
Preparation for surgery
Complete mechanical bowel preparation is essential for transabdominal repair of RVF and is also recommended for local repair. The practice of including poorly absorbed oral antibiotics in the bowel preparation is under scrutiny. Data suggest that administering intravenous (IV) antibiotics in such a way as to ensure appropriate tissue levels at the start of the procedure is sufficient for prophylaxis. The author recommends that prophylactic IV antibiotics be given preoperatively to all patients undergoing RVF repairs, whether 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 povidone-iodine. 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 on, the use of ureteral catheters may aid in dissection.
Local repair
Transanal advancement flap repair
The best results have been reported with transanal advancement flap repair. [27] 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. [28]
Transvaginal inversion repair
The vaginal mucosa is circumferentially elevated, exposing the fistula. Two or three concentric purse-string sutures are used to invert the fistula into the rectal lumen. The vaginal mucosa is reapproximated. This approach has generally been considered suitable only for small, low fistulas in otherwise healthy tissues with an intact perineal body. It is rarely performed today.
Bioprosthetic repair
A 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 requires 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
In a conversion to complete perineal laceration with layer closure, [3] 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 about juxtaposed suture lines.
Simple fistulotomy
Simple fistulotomy 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 repair
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. [29] All of these procedures have the goal of interposing healthy tissue between vaginal and rectal repairs. They are well described in the plastic surgery literature.
Bricker patch
The onlay Bricker patch also has been used to repair RVFs, chiefly those produced by radiation. Briefly, 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.
An advantage to this procedure is that it is less difficult than resection and therefore may be less likely to cause hemorrhage or organ injury. A disadvantage is that the radiation-damaged rectum is left in place and in use, with the possibility of further morbidity, including bleeding and stricture.
Although situations exist where 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.
Over-the-scope clip
Tong et al reported results from a nonrandomized prospective monocentric study of 16 consecutive patients (median age, 40.1 years) who underwent RVF repair with the Over-The-Scope Clip Proctology system (Ovesco Endoscopy, Cary, NC). [30] The primary outcome was RVF healing at 8 months; assessment of morbidity and timing of RVF recurrence were secondary outcomes. Seven of the 16 patients (43.7%) had successful primary healing of the fistula. Short-term complications were rare: Four patients experienced pain, and two had spontaneous clip detachment. Most recurrences developed shortly after the procedure (median delay, 45 days; range, 16-217).
Management of RVF associated with Crohn disease
RVFs associated with Crohn disease are difficult to manage. [5, 31] 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, though 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. [32]
Postoperative Care
Local repair
Attention must be paid 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. Patients need to refrain from sexual activity or any physical activity more strenuous than a slow walk for 3 weeks.
Transabdominal repair
Postoperative care after transabdominal repair 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, in the expectation 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 postoperative day 1.
Early ambulation is beneficial in many ways. Continue perioperative prophylaxis for thromboembolic events until the patient is ambulating well.
Complications
Local repair
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 Prognosis). Rarely, postoperative pain precipitates urinary retention.
Transabdominal repair
Complications of transabdominal repair may include the usual complications of any laparotomy with bowel resection, including fistula recurrence. The most common 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.
Long-Term Monitoring
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.
If specific signs and symptoms are present, they are investigated appropriately. For example, fever, diarrhea, and low abdominal pain indicating an abscess are evaluated by means of computed tomography (CT) of the abdomen and pelvis. In this setting, physical examination may be difficult because of patient discomfort.
