Rectovaginal fistula is defined as an abnormal epithelial-lined connection between the rectum and vagina. It is frequently seen as a bothersome condition for both patients and surgeons, because of the distressing and annoying signs as well as its high repair failure rate.
The presentation shows no major variation from case to case. A little group of patients appear to be asymptomatic, while the majority frequently report the distressing symptom of the passage of flatus and stools through the vagina, especially when patients are affected by diarrhea. The condition is further worsened by fecal incontinence as a consequence of sphincter damage. This clinical situation is usually followed by the appearance of inflammation in the form of vaginitis or cystitis. Fecal incontinence is particularly frequent in patients who have experienced an obstetrical trauma, with a frequency of up to 50%.
Abnormalities observed in the rectal mucosa or a previous and coexisting fistula-in-ano usually indicates the presence of Crohn disease. The prompt diagnosis of this condition is paramount, as it might lead to an inappropriate surgical intervention which further worsens the patient's situation.
The presence of a sepsis is usually confirmed by laboratory studies which include:
RVF appears elusive on physical examination , and this is the reason why its presence has to be confirmed with other tests such as:
The physical examination serves to assess the physical integrity of the tissues surrounding the fistula, as well as localizing its position, and it can be very valuable to assess anal sphincter before planning surgical procedures. When the fistula is small in size, the physician may notice the presence of a palpable depression and pit-like defect in the anterior midline of the rectum. The mucosa of the fistula track is generally darker than the vagina's, which might be affected by vaginitis.
The physical examination of suspected RVF cases should include a careful inspection of the rectum, vagina, and perineal body. Digital examination is particularly advised, as it allows to locate low or anovaginal fistulas when small dimples are present, which in turn can be easily confirmed by anoscopic and speculum examination. The physical examination is carried out by inserting a finger in the anus and another in the vagina. Obviously, the higher the position of the fistula, the more difficult the diagnosis will be.
Of note, many fistulas following obstetric or operative trauma heal spontaneously and require no further treatment. However, the presence of the fistulas might be persistent and cause the appearance of local cases of inflammation. When this condition occurs, the patient needs to be treated with the due approach and set of techniques.
Experts suggest to perform a biopsy on the area under examination, to rule out the possibility of neoplasm. If the fistula is the result of a particular trauma, the therapy consists in draining the abscesses and treating infections with antibiotics. The tissues affected should heal within 6-12 weeks, while the related symptoms and signs can be greatly diminished if the due dietary modifications are applied.
In case of inflammatory bowel disease, repair is possible while the patient is on steroids, even though with a very high risk of failure. The surgical operation consists of a local or transabdominal approach with a minimum level of invasivity , especially in the cases of high RVF originated from neoplasms, radiation therapy, or inflammatory bowel disease. The approach should be accompanied by treatments aimed at restoring bowel function and controlling diarrhea, as well as a course of antibiotics and immunosuppressive medications to prepare the patient for the surgical operation. If the tissues surrounding the fistula appear to be healthy and in good conditions, surgical repair can be performed immediately, otherwise a period of preparation ranging from 3 to 6 months is recommended. The most common surgical operation is advancement flap  and its many variations, all based on the approach of excising and closing the fistula rectal portion, then covering everything on the fistula high pressure side with a vascularized musical flap.
In addition to advancement flaps, another approach has recently been adopted, which was developed for the treatment of intersphincteric anorectal fistulas. The surgical procedure concerned is called LIFT (ligation of intersphincteric fistula tract), and consists of dissecting the bloodless portion after the fistula lying between the external and internal anal sphincters.
RVF has always been an agonizing disorder for the patients and a troublesome condition for physicians, which requires an individualized and systematic approach based on size, etiology, location, as well as the right techniques to get the most out of the treatment. The worst cases are represented by the patients affected by recurrent RVF, who have the poorest prognosis for final repairs . In this case, experts recommend the use of rectal sleeve advancement, which is reported to have a healing rate of around 75% . However, recurrence seems to be influenced by the etiology and complexity of RVF, and therefore fistulas with obstetric origin and more generally those considered “simple” have a far better prognosis.
The most common etiological factor of RVF is obstetric injury  . The other possible etiologies are described as follows:
RVF might occur following childbirth, something which especially common in underdeveloped countries. The condition may result as the consequence of prolonged labor with necrosis of the rectovaginal septum or an obstetric injury associated with a third- or fourth-degree perineal tear or episiotomy. Other causes for the development of a fistula may be inadequate or interrupted repair or an infection.
Fistula development is particularly frequent with infectious processes inside the rectovaginal septum. For instance, cryptoglandular anorectal abscesses and Bartholin gland infections might drain spontaneously, leading to RVF. The most common infectious causes of fistulas include diverticular disease in the setting of previous hysterectomy, but cases associated with tuberculosis and lymphogranuloma venereum have also been observed. Moreover, malignancies have been reported as cause of RVF, usually seen with large extent in the uterine, rectal, vaginal, and cervical areas, and frequently treated with radiological methodologies. After radiological treatment, proctitis appears which is then followed by anterior rectal wall ulceration that finally results in fistula formation within 6 to 24 months after the initial radiological therapy.
Fistulas might also develop from operative trauma, especially in the context of anorectal and vaginal surgical procedures. For example, during low stapled colorectal anastomoses, the vaginal walls end up being incorporated in staplers or anastomotic leaks during formation of abscesses, which in turn result in the development of a fistula. Other surgical risks include pelvic procedures, which might cause the formation of a high RVF, hysterectomy after radiation therapy, or unrecognized intraoperative rectal injury.
Inflammatory bowel diseases are frequently associated with RVF formation, especially Crohn disease as it might cause transmural inflammation of the rectal wall . In this case, RVF usually develops before the appearance of intestinal symptoms . RVF is also often associated with ulcerative colitis, especially in the context of ileo-anal pouch anastomoses characterized by anastomotic leak or pelvic abscess. Complications of radiation therapy or surgical operations such as rectocele repair and restorative proctocolectomy may also lead to RVF.
Rarer etiologies include vaginal dilatation (especially after radiation at the level of the vaginal cuff), fecal impaction, sexual assault, and infections of bacterial or viral origin in subjects affected by HIV immunodeficiency.
The frequency of RVF varies greatly on the basis of the particular etiology. RVF classification is based on its location, size, and etiology, and affects profoundly the treatment options and the possible prognosis for the patient. According to its location, RVF can be divided in two main groups:
RVF is particularly frequent in patients affected by inflammatory bowel disease, especially in those who also present with Crohn disease rather than in those with ulcerative colitis. In this last case, the incident rate of RVF has been found to range between 0.5 and 2.2% .
There are several mechanisms connected with RVF development. The first one is perineal laceration during childbirth, above all in the cases occurring after episioproctotomy, a factor which highly increases the predisposition to develop fistulas. Perineal laceration is particularly frequent in primigravidae, especially when pregnancy becomes precipitous, and with the use of forceps or vacuum extraction. The probability of developing RVF further increases if perineal laceration is not promptly diagnosed and duly treated, or in case of secondary infections.
Another factor which might cause the development of RVF is a vaginal or rectal surgical procedure that is not properly performed. This frequently happens when surgical procedures are carried out near the dentate line, and complications can become very likely especially in the context of stapled hemorrhoidopexy, STARR (stapled transanal rectal resection), and TRANSTAR (transanal stapled resection) . The list of surgical procedures should also include pelvic operations, which can cause the development of high RVF. It should be noted that the mechanical trauma responsible for the appearance of the fistula can also derive from a traumatic injury, be it penetrating or blunt, or from a forceful coitus which has created a heavy mechanical stress.
RVF has also been seen associated with Crohn disease  and ulcerative colitis. In this case, the fistula can appear as either a primary event or as a secondary symptom following the appearance of a perirectal abscess after the development of perianal sepsis.
Radiation is regarded the mainstay of treatment for pelvic malignancies and can be included in the list of pathophysiological mechanisms responsible for the development of RVF . Fistulas, in fact, may frequently arise after this type of therapy, and they only become apparent months after the completion of the treatment. In general, it takes from 6 to 24 months on average for physicians to be able to observe the development of a fistula following radiation therapy. In this context, the risk of fistula formation is further increased by other factors such as smoking, previous abdominal or pelvic operations, diabetes mellitus, or hypertension. Since any type of neoplasm, primary, recurrent, or metastatic, can trigger the development of RVF, it is very important to use biopsy in order to differentiate any radiation-related change in the fistula from a recurrent tumor.
Lastly, infection is also another pathophysiological mechanism which might cause RVF. The types of infection which are mostly correlated with cases of RVF include perirectal abscess and diverticulitis, to which should be added the less frequent types such as Bartholin gland abscess, lymphogranuloma venereum, and tuberculosis.
There is no known method to prevent the development of RVF.
Rectovaginal fistula (RVF) is a tract which connects the rectum with the vagina. It appears as a devastating condition for the patients and a serious technical challenge for surgeons due to the difficulty of the related surgical procedure. RFV has a number of etiologies which include obstetric injury, inflammatory bowel disease, trauma, malignant processes, and possible complications of radiological and surgical procedures. Treatment depends on many factors such as etiology, size, location of the fistula itself, and includes different repair options like local repairs, abdominal operations, and transfer techniques.
A rectovaginal fistula (RVF) is a connection that develops in the lower part of the large intestine and vagina. Because of this defect, the gases and stools present in the bowels can leak out through the vagina, causing a distressful and shocking situation for the patient affected. RVF appears when one of the following conditions occurs:
Symptoms depend on the size and location of the fistula, and range from minor signs to significant conditions such as incontinence. These can be summed up as follows:
In some cases fistulas might heal spontaneously. However, the majority of the patients need surgical procedures that are aimed at removing the fistula and closing the opening with portions of the surrounding healthy tissues.