Rectovaginal and Rectourethral Fistulas
Andrew A. Shelton, MD
Department of Surgery
Section of Colon and Rectal Surgery
Stanford University School of Medicine
A rectovaginal fistula is an abnormal communication between the epithelial lined surfaces of the vagina and anorectum. Fistulas between the anorectum and vaginal are relatively uncommon, accounting for less than 5% of all anal fistulas. The symptoms due to the fistula and the management problems that they pose can be quite vexing to both the patient and the surgeon.
The most common symptoms of a rectovaginal fistula are the passage of gas, fecal material, or mucus from the vagina. These symptoms can, at times, be misinterpreted as fecal incontinence. Additional symptoms include dyspareunia, chronic vaginal discharge. With a small fistula, the only symptoms may be a malodorous vaginal discharge or recurring episodes of vaginitis. At other times, symptoms related to the underlying disease may predominate. Tenesmus, diarrhea, and rectal bleeding are prominent symptoms in patients with inflammatory bowel disease. These symptoms are understandably quite distressing to the patients. Sometimes, a rectovaginal fistula may be asymptomatic.
CLASSIFICATION OF FISTULAS
A number of factors related to a rectovaginal fistula can be used to classify the fistula. They include size, location, and cause of the fistula. These factors are used to classify the fistula into simple or complex fistulas.
Simple rectovaginal fistulas
- Low or mid vaginal septum
- <2.5 cm in diameter
- Due to trauma or infection
Complex rectovaginal fistulas
- High rectovaginal septum
- >2.5 cm in diameter
- Due to inflammatory bowel disease, radiation, or neoplasm
- Previous failed repairs
A rectovaginal fistula can be the common end point of a variety of disease states. Fistulae can be congenital or acquired. Acquired rectovaginal fistulas with be the topic of this review. Most acquired rectovaginal fistulas are caused by obstetric injury, inflammatory bowel disease, infection, or trauma. the reported frequency of each is strongly influenced by referral patterns.
Obstetric injury is the most common cause of acquired rectovaginal fistulas, accounting for 50-90%. Obstetric rectovaginal fistulas are most commonly seen after an inadequately repaired or unrecognized fourth-degree perineal laceration or a repair that breaks down due to infection. In western countries, primiparity, increased birth weight, the use of midline episiotomy, and the use of vaginal forceps for delivery are factors that have been associated with an increased risk for fourth degree perineal laceration. In developing countries, necrosis of the rectovaginal septum due to prolonged or stalled second stage of labor can also cause a rectovaginal fistula. Rectovaginal fistula, is however, a rare birth complication, occurring in less that 0.1% of vaginal deliveries.
Rectovaginal fistulas have been reported as occurring in both patients with Crohn’s disease and ulcerative colitis. However, the transmural nature of the inflammatory process seen in Crohn’s disease results in a higher rate of fistulization. In a series of 886 women with Crohn’s disease at St. Mark’s Hospital, 10.2% developed some form of anovaginal or rectovaginal fistula. Rectovaginal fistula fistula and other forms of perianal disease may precede intestinal symptoms. In general, the more distal the location of the intestinal disease, the higher the risk of rectovaginal fistula. Fever than 25% of patients with Crohn’s disease confined to the small bowel have anal disease, compared to more than 50% of patients with colorectal disease.
Rectovaginal fistula can result from complications of transanal or transvaginal surgery as well as from complications from hysterectomy, anterior resection of the rectum or ileal pouch anal anastomosis. The incidence of rectovaginal fistula after surgery for low rectal cancer is reported to be from 0.1-10% and the reported incidence of pouch vaginal fistula after ileoanal J pouch is 3-12%. These fistulas result from incorporation of the the posterior vaginal wall in the EEA staple line of a double-stapled anastomosis or from the drainage of a pelvic abscess from an anastomotic leak through the vagina. Rectovaginal fistula has also been reported as a complication of PPH treatment of internal hemorrhoids and the STARR procedure for obstructed defecation.
Any infectious process that involves the rectovaginal septum can result in a rectovaginal fistula. The most common infectious cause is a c fistula abscess that drains through the rectovaginal septum into the vagina. Drainage of a diverticular abscess through the rectovaginal septum can result in a high rectovaginal fistula. Less common infectious causes include tuberculosis, lymphogranuloma venereum, and schistomosomiasis.
MALIGNANCY/CANCER TREATMENT RELATED
Primary or recurrent cancers in the anogenital region may present as rectovaginal fistulas, either from local extension of disease or as a complication of therapy. Adjuvant radiation therapy plays an increasing role in the management of many cancers and is a primary therapy for squamous cell carcinoma of the cervix and the anal canal. Rectovaginal fistula is a well described complication of pelvic radiation therapy. I t can occur as a result of a deeply eroding radiation induced ulcer on the anterior rectal wall or from necrosis of carcinoma involving the rectovaginal septum. The incidence of rectovaginal fistula following pelvic radiotherapy varies form 0.3% to 6% and is related to the dose of radiation therapy and the technique employed. Most fistulas related to treatment develop between six months and two years after therapy. Prior hysterectomy increases the risk of fistula formation.
EVALUATION OF THE PATIENT WITH A RECTOVAGINAL FISTLA
Goals in the history and exam of a woman with a rectovaginal fistula are to identify the cause of the fistula, the location of the fistula, the extent of any underlying disorder or associated injury, and to assess the local tissues in order to determine when to repair the fistula and what the best surgical option will be. The exact investigation required will depend on the cause of the fistula.
HISTORY AND PHYSICAL EXAM
The diagnosis of a rectovaginal fistula is usually relatively straightforward by the patient’s history. Most often, the fistula is felt on digital rectal exam as an anterior pit in the anterior midline. It is often easily visible on anoscopy. If the fistula is small, it may only appear as a depression or pit-like defect. In the case of an obstetric injury, the perineal body may be attenuated and a sphincter defect may be palpable anteriorly. Multiple perianal fistulas should raise the suspicion of Crohn’s disease. On vaginal exam, the dark red color of the granulation tissue or mucosa of the fistula contrasts with the light pink vaginal mucosa.
Sigmoidoscopy completes the exam when perineal infection or trauma is the cause of the fistula. In other causes, such as inflammatory bowel disease or malignancy, colonoscopy or small bowel imaging may be necessary. Biopsy should be performed on any abnormal mucosa, ulcers, or mass lesions. Biopsy should also be performed on all rectovaginal fistulas occurring after radiation therapy as up to one third of these will harbor recurrent carcinoma.
Occasionally, the diagnosis of a rectovaginal fistula remains elusive despite highly suggestive symptoms. In these cases, a careful examination under anesthesia is in order. If the location of the fistula is not identified during an exam under anesthesia, a number of techniques have been used to confirm the presence of a fistula. Detection of air bubbles in a saline filled vagina during proctoscopy can help localize an occult rectovaginal fistula. Dilute methylene blue can be instilled in the rectum and retained for 20 minutes with a vaginal tampon in place. Staining of the tampon confirms the presence of a fistula. Alternatively, a radiograph may be made of a tampon after performing a contrast enema.
Numerous techniques are available for the management of rectovaginal fistulas, attesting to the often difficult nature of this condition and the lack of a single clearly superior technique. The choice of technique depends on the nature of the fistula and any previous attempts at repair, as well as the experience and preferences of the surgeon.
Optimum medical management of the inflammatory mucosal disease is an integral part of the management of the patient with a rectovaginal fistula occurring in the setting of Crohn’s disease. Although permanent closure of a rectovaginal fistula with medical therapy alone is unlikely, surgical repair of a fistula in setting of active perianal Crohn’s disease is likely to fail.
There are some general principles that apply to most of the surgical procedures discussed below. Mechanical and antibiotic bowel preparation is usually used. Procedures done via the transanal or transperineal route should be done in eh prone jack-knife position for optimal exposure. A head light is very helpful in illuminating the operative field. When using a transanal approach, the buttocks are taped apart and a Lone Star Retractor can be used to efface the anal canal. Low-lying fistulas can be easily exposed with a Pratt bivalve anoscope. For higher fistulas, Wylie renal vein retractors, narrow Deaver retractors, or narrow malleable retractors can be used. Procedures done transvaginally are done in the lithotomy position. General anesthesia or regional techniques are usually used , although local anesthesia and conscious sedation may be appropriate in certain cases.
TRANSANAL TECHNIQUES: Procedures for rectovaginal fistulas performed transanally include layered closure, endorectal advancement flap, and anocutaneous advancement flap.
Layered closure: A layered closure can be performed through a transanal, transvaginal, or transperineal approach. A longitudinal or elliptical incision is made around the fistula site and mucosal flaps are raised for 2-3 cm. The fistula is the excised and the vaginal mucosa, rectovaginal septum, and rectal mucosa are closed in sequential order. The reported success rate ranges from 88-100%
Endorectal advancement flap: A Pratt bivalve anoscope is inserted into the anus and the fistula site is identified. A trapezoid shaped flap of mucosa, submucosa, and partial thickness of the inner circular muscle is raised. The apex of the flap should be 1 cm distal to the fistula. The base of the flap should extend at least 4.0 cm proximal to the fistula and should be at least twice as wide as the apex to insure adequate blood supply to the flap. The fistula tract is then curetted. The circular smooth muscle is then mobilized laterally and re-approximated in the midline with interrupted absorbable sutures, closing the fistula. The distal portion of the flap is excised, including the rectal opening of the fistula. The flap is then sutured in place. The vaginal opening of the fistula is left open for drainage. Reported success with this technique is 54-100%
Anocutaneous advancement flap: A Pratt bivalve anoscope is used to identify the fistula opening in the anal canal. The anal mucosa around the fistula is excised. Beginning proximal to the level of the fistula, an anocutaneous flap with a wide base at the perineum is created. The scarred, fibrotic apex of the flap is excised to provide a fresh flap with a good blood supply. The defect in the circular smooth muscle is then closed with absorbable sutures. The anocutaneous flap is then advanced into the anal canal and sutured at the apex and laterally. This techniques should be considered for very distal rectovaginal fistulas in which a mucosal advancement flap may lead to the development of a mucosal ectropion.
Rectal Sleeve Advancement: Rectal sleeve advancement is an alternative transanal repair that is often usefully for a Crohn’s related rectovaginal fistula with an associated anal stenosis. A circumferential incision is made at the dentate line and deepened through the submucosa. Dissection is continued in this plane, exposing the internal anal sphincter. Above the anorectal ring, the dissection becomes full thickness and proceeds proximally until healthy, non-scarred tissue is encountered. Proximal dissection should continue until there is enough mobilization of the distal rectum, that it can be brought down and sutured to the dentate line. The rectum is then pulled down through the anal can and the diseased, distal segment is excised. The fistula opening in the vaginal is closed. The healthy rectum is then brought down over the sutured fistula opening and sutured to the dentate line. This repair is often done in conjunction with a diverting stoma.
Bioprosthetics: During the last decade, biologic mesh techniques have been described for the treatment of anal fistulas including rectovaginal fistulas. These prostheses are typically placed transanally through the fistula tract and sutures in place, closing the anal side of the fistula. Initial enthusiasm with this technique due to its low morbidity and 80% success rate has been tempered by subsequent reports showing a much lower success rate.
Fistula Inversion: Inversion of the fistula is one of the simpler techniques. The patient is placed in the lithotomy position. A circumferential incision is made in the vaginal mucosa around the fistula opening and a circular mucosal flap is raised. The fistula tract is cored out and a purse-string suture is placed around the fistula opening. When the suture is tied, the fistula tract is inverted into the rectum. The vaginal mucosa is then closed with interrupted absorbable sutures. A 72% success rate has been reported.
Vaginal advancement flap: This is a technique similar to the transanally performed mucosal advancement flap, with the difference being that the flap is performed from the vaginal side. A flap of vaginal mucosa is raised beginning inferior to the fistula and mobilized cephalad and laterally. The fistula site is excised and the rectal opening is closed with absorbable sutures. A levatorroplasty is often done prior to suturing down the flap. This brings healthy, vascularized muscles between the vagina and rectal suture lines. The excess vaginal mucosa including the fistula is excised and the flap sutured in place.
Perineoproctotomy: A perineoproctotomy is one of the most common techniques used by gynecologists for repair of low lying rectovaginal fistulas. The fistula is identified and the perineal bridge, including the skin, sphincter muscle and vaginal mucosa are divided. This essentially converts the fistula into a fourth degree perineal laceration. The fistula tract is excised and the resulting defect is closed in layers. Results are generally good with reported success rates ranging from 88-100%.
Overlapping Sphincteroplasty: This is the procedure of choice for a woman with a rectovaginal fistula, a sphincter injury and associated fecal incontinence. A curvilineal incision is made i the perineum and flaps are raised consisting of the skin and anoderm distally and the rectal mucosa and submucosa proximally. As the dissection proceeds cephalad, the fistula is eventually divided. The divided ends of the internal and external anal sphincter are identified and mobilized posteriorly and laterally. Care must be taken not to injure the pudendal nerves. The defects in the rectum and vaginal are closed with absorbable sutures. The sphincter muscles are then overlapped in the midline and sutured together with horizontal mattress sutures. This provides a bulk of vascularized tissue between the rectal and vaginal walls. A levatorroplasty can also be performed by approximating the levator muscles in the midline before performing the sphincter repair. The flap of anoderm is then sutured to the sphincter muscle and the skin and subcutaneous tissue of the the perineal incision partially closed. Success rates of 86-100% are reported.
Tissue Interposition: A variety of technique to transpose healthy muscle between the rectum and vagina for repair of rectovaginal fistulas have been described. These include using the labial fat pad (Martius Procedure) and the gracilis muscle. These techniques are particularly useful in the repair of rectovaginal fistulas after previous failed repairs as well as when dealing with chronically radiated tissue which often heals poorly.
Abdominal surgery may be necessary for some complex or proximal rectovaginal fistulas. A large rectovaginal fistula due to an EEA stapler injury may require resection of the anastomosis and a neocolorectal or coloanal anastomosis. It is important to wait a sufficient amount of time after the initial operation to allow the local inflammatory changes to subside. A temporary diverting loop ileostomy may be necessary during this period to ameliorate the symptoms of the fistula. A malignant or radiation induced rectovaginal fistula may require resection with a coloanal anastomosis to repair. A rectovaginal fistula associated with perianal Crohn’s not responding to medical therapy or with an associated stricture may eventually require proctectomy and a stoma.
Rectourethral fistulas can be either congenital, usually associated with imperforate anus, or acquired. Congenital rectourethral fistulas will not be covered her. Acquired rectourethral fistulas are much less common than rectovaginal fistulas. They are most commonly associated with treatment of prostate cancer. An unrecognized rectal injury during a radical retropubic prostatectomy can result in a rectourethral fistula. The most common presenting symptom is fecluria. Rectourethral fistulas have also been described following high dose brachytherapy for prostate cancer. Less common causes include traumatic instrumentation of the urinary tract.
Initial management of a rectourethral fistula often includes fecal diversion and urinary catheterization. A variety of surgical approaches have been used to repair rectourethral fistulas. These include transperineal repair with muscle interposition (gracilis or dartos muscle) and transsphincteric (York-Mason) repair with layered closure of the fistula.
Lowry AC and Hoexter B, Benign Anorectal: Rectovaginal Fistulas in The ASCRS Textbook of Colorectal Surgery; Wolfe BG, et al., eds. Springer, Springer, New York, NY, 2007; pp 215-227.
Shelton AA and Lowry AC, Management of Rectovaginal Fistulas, in Ambulatory Anorectal Surgery, Bailey HR and Snyder MJ, eds. Spirnger, New York, NY, 2000; pp 130-140.
Chanpagne BJ and McGee MF, Rectovaginal Fistulas. Surgical Clinics of North America, 2010; 90: 69-82.
Poritz LS, Rowe WA, Koltun WA. Remicade does not abolish the need for surgery
in fistulizing Crohn’s disease. Dis Colon Rectum 2002;45:771–5.
Chew SB, Rieger NR. Transperineal repair of obstetric-related anovaginal fistula.
Aust N Z J Obstet Gynaecol 2004;44:68–71.
Cassadesus D, Villasana L, Sanchez IM, et al. Treatment of rectovaginal fistula:
a 5 year review. Aust N Z J Obstet Gynaecol 2006;46:49–51.
Hull TL, Fazio VW. Surgical approaches to low anovaginal fistulas in Crohn’s
disease. Am J Surg 1997;173:95–8.
Ellis N. Outcomes after repair of rectovaginal fistulas using bioprosthetics. Dis
Colon Rectum 2008;51:1084–8.
Hoexter B, Labow SB, Moseson MD. Transanal rectovaginal fistula repair. Dis Colon Rectum 1985;28:572–575.
Baig MK, Zhao RH, Yuen CH, et al. Simple rectovaginal fistulas. Int J Colorectal Dis 2000;15:323–327.
Hesterberg R, Schmidt WU, Muller F, Roher HD. Treatment of anovaginal fistulas with an anocutaneous flap in patients with Crohn’s disease. Int J Colorectal Dis 1993;8:51–54.
Pinedo G, Phillips R. Labial fat pad grafts (modified Martius graft) in complex perianal fistulas. Ann R Coll Surg Engl 1998;80:410–412.
Rius J, Nessim A, Nogueras JJ, Wexner SD. Gracilis transposition in complicated perianal fistula and unhealed perineal wounds in Crohn’s disease. Eur J Surg 2000;166:218–222.
Nowacki MP, Szawlowski AW, Borkowski A. Parks’ coloanal sleeve anastomosis for treatment of postirradiation rectovaginal fistula. Dis Colon Rectum 1986;29:817–820
Sher ME, Bauer JJ, Gelernt I. Surgical repair of rectovaginal fistulas in patients with Crohn’s disease: transvaginal approach. Dis Colon Rectum 1991;34:641–648.
Topstad DR, Panaccione R, Heine JA, Johnson DR, MacLean AR, Buie WD. Combined seton placement, infliximab infusion, and maintenance immunosuppressives improve healing rate in fistulizing anorectal Crohn’s disease: a single center experience. Dis Colon Rectum 2003;46:577–583.