Rectovaginal fistula is a congenital or acquired pathological communication between the cavities of the rectum and the vagina. It is manifested by the discharge of gases, mucus and feces through the vagina, pain in the perineum, soreness during sexual intercourse, dysuric disorders. For diagnosis, vaginal examination, rectovaginal examination, rectoromanoscopy, fistulography are used. Treatment can only be operative with excision and/or replacement of the defect of the rectal-vaginal septum with the patient’s own tissues, a collagen patch or a plug.
General information
Rectovaginal fistulas are relatively infrequent. Only in 0.001% of cases they are congenital, the prevalence of the disease among adults does not exceed 0.33%. Women of reproductive age are most often ill, which is due to the close connection of pathology with traumatization in childbirth. Usually the fistulas of the rectovaginal septum are small (1.0-2.0 mm in diameter), in some cases the size of the fistula holes reaches several centimeters. Although the disease does not pose a threat to the patient’s life, its clinical manifestations cause significant discomfort. Since classical operations to remove such fistulas result in relapses in almost a third of cases, specialists in the field of gynecology and proctology are constantly working to find less invasive and more effective interventions.
Causes
The walls of the vagina and rectum are tightly adjacent to each other on a site of a sufficiently large extent. Therefore, when predisposing conditions occur, the integrity of the rectovaginal septum may be violated with the formation of a rectovaginal fistula. Extremely rarely pathology is congenital — in the vast majority of cases it is formed under the influence of external causes. The formation of a rectovaginal fistula leads to:
- Injuries sustained in childbirth. The septum between the rectum and the vagina can be mechanically torn at the birth of a large fetus, its vacuum extraction or extraction by the pelvic end, the imposition of obstetric forceps, fruit-destroying operations. Very rarely, the injury is accompanied by rough implementation of obstetric aids (turning the fetus on the leg, etc.).
- Prolonged course of labor. With a long anhydrous interval, soft tissues die off due to their ischemia when the fetal head is pressed against the pelvic bone. With significant areas of damage, a postpartum fistula is formed on 3-8 days. The risk is especially increased in women in labor with an incorrect fetal position and a narrow pelvis.
- Infection of postpartum ruptures. Even with timely suturing of the rupture of the vaginal wall, the muscle that raises the anus or the anal sphincter, wound inflammation is possible. In such cases, its healing slows down, the sutures in the rectovaginal wall become untenable, a fistula occurs.
- Injury of the rectum. The rectal-vaginal septum can be damaged during surgical interventions to remove benign and malignant neoplasms of the rectum. In rare cases, such injuries are observed during medical manipulations (rough insertion of an enema tip, thermometer, underwater intestinal lavage, etc.) or anal sexual intercourse.
- Diseases of the genitals and intestines. Damage to the rectovaginal septum is complicated by Crohn’s disease, diverticulosis of the rectum. Tissue destruction is possible with the disintegration of volumetric neoplasms in patients with cancer of the colon, cervix, and vaginal tissues.
- Abscesses. The fistula passage between the vagina and the rectum can form at the site of the breakthrough of pus accumulations in paraproctitis, tuberculosis of the genitals, syphilis.
Pathogenesis
The key link in the formation of fistulas in the rectovaginal septum is increased pressure in the rectum (compared to the vagina). When any communication occurs between these organs, the intestinal mucosa quickly turns into the vaginal cavity. It takes no more than 7 days for its circular accretion to the edges of the defect. Since the contents of the intestine constantly enter the resulting channel, granulation of the damage site does not occur. The complete formation of a typical lip-shaped fistula lasts up to 4 months (except in cases of massive crushing of tissues during prolonged labor or penetrating wounds).
Classification
The classification of rectovaginal fistulas is based on their shape and location relative to the edge of the anal opening. There are the following types of fistulas:
- High — localized at a distance of 60 mm or more from the edge of the anus.
- The middle ones are located 30-60 mm from the edge of the anal opening.
- Low — localized no higher than 30 mm above the anus.
Most fistulas have a classic lip-shaped shape, their openings in the vagina and rectum coincide, and the canal is short and straight. Against the background of acute paraproctitis, colitis or penetrating wounds of the anal area, so-called tubular fistulas are formed, which are characterized by multiple channels, congestion and sealed cavities with pus in the pararectal tissue.
Symptoms
The symptoms are determined by the size and localization of the fistula. Typical signs are the passage of intestinal gases through the vagina, uncontrolled secretion of mucus (with small mouths) and fecal masses (with large fistulas). In some patients with an infection that has joined, vaginal discharge becomes purulent, discomfort, painful sensations, burning and itching of the vagina and perineum occur. When the inflamed tissues that form and surround the fistula are stretched, a woman experiences pain during sexual intercourse. With intense pain syndrome, sexual relations become impossible.
Despite the most thorough hygienic care, the patient constantly feels an unpleasant smell of feces, which can cause psychoemotional disorders — depressed mood up to depression, irritability, tearfulness. When inflammation spreads to the urinary system, the clinical picture is complemented by dysuric disorders — cramps and pain during urination.
Complications
Rectovaginal fistulas are complicated by local and ascending infectious and inflammatory diseases of the genital and urinary systems. Such patients often have acute and chronic colpitis, endocervicitis, endometritis, salpingitis, adnexitis, parametritis, urethritis and cystitis. When the uterine appendages are involved in the inflammatory process, menstrual function may be disrupted until the complete cessation of menstruation. The risk of infertility and miscarriage increases. On the part of the gastrointestinal tract, complications such as constipation or, conversely, frequent loose stools are detected.
Diagnostics
If a rectovaginal fistula is suspected, a set of examinations is prescribed to detect the fistula canal, assess its size, shape and location. For diagnosis, the most informative are:
- Examination on a chair. When visualizing in mirrors, a characteristic hole is found on the back wall of the vagina, through which mucus or feces can enter. Manual examination confirms the presence of a fistula, reveals scarring of surrounding tissues. If necessary, you can use a button probe.
- Two-handed rectovaginal examination. Expands the possibilities of a conventional gynecological examination, allows you to detect a junction on the anterior wall of the rectum, as well as its connection with the vagina.
- Rectoromanoscopy. With a detailed examination of the rectal mucosa, the fistula opening is easily determined on it. In doubtful cases, with the help of an endoscopic device, tissue sampling can be performed for examination.
- Fistulography. One of the most informative diagnostic methods. The introduction of a radiopaque substance into the fistula, followed by a series of images, provides an accurate determination of the number, direction and extent of fistula passages, reveals congestion and cavities.
In more complex diagnostic cases, chromorectoromanoscopy, rectal ultrasound with a rectal sensor, vagino-, procto- and irrigography are recommended as additional methods. To assess the functional viability of the anal sphincter, electromyography and sphincterometry can be prescribed. Differential diagnosis is performed under the assumption of the existence of other diseases complicated by rectal-vaginal fistula, such as malignant tumor, diverticulosis, Crohn’s disease, etc. A proctologist is usually involved in the diagnosis, in addition to a gynecologist.
Treatment of rectovaginal fistula
The only method of treating the disease is surgical. In acute trauma of the rectovaginal septum, suturing of the defect is shown during the first 18 hours. With this approach, the probability of septic complications is minimal. The elimination of formed fistulas is a difficult task and is often performed in two stages. In some cases, when the risk of consequences from the intervention exceeds the inconvenience experienced by the patient, it is recommended to refrain from surgery. A wait-and-see tactic is justified for small-sized fistulas with minimal clinical manifestations (the release of small amounts of gases and mucus in the absence of pain and complications).
In 70% of cases, 2-3 months before the intervention to eliminate the fistula, a colostomy is applied to the anterior abdominal wall to remove feces. Temporary shutdown of the lower intestine creates conditions for the treatment of local inflammation, after which some fistulas heal on their own. To date, more than 30 techniques have been developed for the surgical treatment of rectovaginal fistulas. Various techniques differ both in access (rectal, perineal, vaginal, and in case of extensive lesions — abdominal) and in the technique of plastic surgery. To eliminate a tissue defect , use:
- Auto- or allograft. After excision of the scar-altered tissue and the fistula, the fistula is closed with a flap of the patient’s own tissue or a collagen patch. For autotransplantation, tissues of the rectal or vaginal wall or a vascular-fat flap from the base of the labia minora are taken.
- Biological collagen plugs. The advantage of the method is safety and low invasiveness. The intervention is performed without incisions, while an obturator made of collagen fibers is inserted into the fistula canal. The plug is fixed with stitches from the side of the rectum, well covers the defect of the rectovaginal wall and is completely replaced by its own tissues in a few weeks.
- Titanium clips. A new method of treating fistulas of the rectal-vaginal septum. It involves squeezing the walls of the channel with a special clip made of titanium nickelide, which has a shape memory. It is characterized by painlessness and a light course of the postoperative period.
If there are indications, surgical intervention to eliminate the fistula canal is combined with anterior levatoroplasty, vaginoplasty and sphincteroplasty (with a defect of the muscle compressing the anus). After complete healing of the fistula, the colostomy, if it was superimposed, is closed.
Prognosis and prevention
The tissues from which the rectovaginal septum is formed are very thin and are usually altered due to scar-inflammatory processes. Therefore, the frequency of relapses of the disease reaches 18-32% with traditional operations and 10-15% with the use of biological collagen plugs. If a stable result is not obtained within 3-4 months, a second radical intervention is carried out. With the right treatment tactics, positive results are achieved in 96% of cases. If a woman plans to become pregnant after the operation, delivery is possible only through cesarean section.
For prevention, it is recommended to choose the optimal obstetric tactics for pregnant women with a narrow pelvis, a large fetus, with atypical presentation and insertion of the head, early discharge of amniotic fluid. Careful performance of obstetric operations and benefits, invasive manipulations, high-quality revision of the birth canal and rapid suturing of injuries play an important role.
