Urethrovaginal fistula is a type of genitourinary fistula with the formation of a message between the urethra and the vagina. It is manifested by the excretion of urine through the vagina, its partial or complete incontinence, dysuria, spraying of a jet. Gynecological examination, colposcopy, probing of the fistula canal, urethrocystoscopy, intravesical administration of pigment substances, urodynamic studies are used for diagnosis. Treatment is only surgical. Taking into account the features of the fistula, its suturing, urethral and vaginal plastic surgery, sling operations are performed.
Urethrovaginal fistula are a rare urogynecological pathology, which is detected in 10-15% of patients with urogenital fistulas. The prevalence of the disease and the causes of its occurrence directly depend on the level of development and availability of medical care, national traditions. In developed countries, such fistulas are more often found in women over 35-40 years old who have undergone various urogynecological interventions. In developing and poor countries, urethrovaginal fistula channels usually appear in young women due to insufficient care during prolonged or difficult labor. The situation is aggravated by the tradition of early marriage and, accordingly, childbirth with insufficient formation of the birth canal.
The fistula passage between the vaginal cavity and the urethra is usually formed as a result of through traumatic damage to the soft tissues separating these organs. Specialists in the field of modern urology and gynecology identify several main groups of causes that in the vast majority of cases provoke the formation of a fistula:
- Urogynecological operations. In almost 2/3 of cases, the communication of the urethra with the vagina occurs after surgical treatment of urological or gynecological pathology. This is due to the expansion of the range of operations performed on pelvic organs. Combined intraoperative trauma of the urethra and vagina is most likely with the removal of urethral diverticula and paraurethral cysts, anterior colporaphy, injection of volume-forming drugs, cryoablation of urethral polyps, removal of Gartner’s duct cysts or the anterior vaginal wall.
- Complicated labor. Obstetric causes of urethrovaginal fistula formation are detected in almost 25% of patients. More often, the destruction of the walls separating the urethra and the vagina occurs in the first period of prolonged labor due to the compression of soft tissues between the fetal head and the pubic bone. Prolonged ischemia leads to tissue necrosis, followed by the formation of a fistula. End-to-end damage is also possible with ruptures of the birth canal, careless obstetric operations (applying forceps, vacuum extractor, fetal extraction by the pelvic end).
- Accidents and accidents. Household, industrial, road injuries cause the formation of a fistula passage connecting the urethra with the vaginal cavity in 4.0-5.4% of cases. The cause of injuries are automobile and railway accidents, the introduction of foreign bodies, rape, falling on a sharp ledge. Both penetrating wounds of the septum between the urethra and the vagina and ruptures with the formation of lacerations are possible. It is extremely rare that tissue necrosis occurs when aggressive chemicals are inadvertently administered.
In extremely rare cases, a fistula is formed as a complication of a genital or extragenital disease or becomes a consequence of its therapy. So, urethrovaginal fistula can appear when the walls of the organs germinate with vaginal cancer, cervix, urethra. Difficult-to-treat variants of fistulas are formed after radiation therapy of oncopathology. The occurrence of a pathological message is possible when the infectious process spreads to the urinary organs in patients with tuberculosis and typhoid fever.
The formation of the urethrovaginal fistula occurs in two stages. First, as a result of traumatic exposure (puncture, rupture, ischemia, chemical or radiation necrosis), a pathological message is formed between the vagina and the urethra. Since at the moment of urination there is a pressure difference between the communicating cavities, the wound healing process is disrupted. Gradually, the walls of the fistula are granulated and epithelized to form a channel of different lengths, cross-sections, and configurations. In some cases, with massive injuries or recurrent course, fibrosclerotic changes are observed in the tissues surrounding the fistula.
When systematizing the forms of urethrovaginal fistula passages, the localization of the fistula, the features of the course and previous treatment, the severity of the disorder are taken into account. The choice of these criteria is justified by the specifics of symptoms in different variants of fistulas and the need to determine the optimal management scheme of the patient. Urologists and gynecologists distinguish the following variants of fistula passages between the vagina and urethra:
- By localization: high-located (the fistula opening is located in the proximal and middle parts of the urethra closer to the neck of the bladder) and low-located (the fistula course begins in the distal part of the urethral canal). The degree and nature of urination disorders directly depend on the localization of the fistula.
- Downstream: primary and recurrent. Primary fistulas are called, which formed after damage. Recurrent fistulas occur repeatedly in place of the primary ones after the plastic surgery. Repeated postoperative recurrence with an increase in clinical symptoms is possible.
- By severity: there are 3 degrees. Fistulas of the I degree of severity include small fistulas of the distal urethra, II degree — fistulas in the middle and proximal parts, complicated by urinary incontinence. At grade III, multiple, recurrent and post-radiation fistula passages are detected, which are difficult to treat.
Symptoms of urethrovaginal fistula
The main manifestation of the disease is the discharge of urine from the vagina. Depending on the diameter of the fistula canal, urination through the vagina can range from insignificant to intense. 85-87% of patients have impaired urination. With the distal location of the mouth of the fistula, the control of urine discharge is usually preserved. If the fistula begins in the middle or proximal parts of the urethra, there is partial or complete urinary incontinence with its spontaneous discharge during physical exertion (coughing, sneezing, laughing) and even at rest in the vertical or horizontal position of the woman. There may also be complaints of dysuric disorders and splashing of a stream of urine.
Due to the irritating effect of urine, activation of opportunistic flora or secondary infection, urethro-vaginal canals are often complicated by infectious and inflammatory processes – vaginosis, vulvovaginitis, exocervicitis, urethritis. There may be an upward spread of infection with the development of endocervicitis, cervicitis, endometritis, salpingitis, oophoritis, adnexitis, cystitis, pyelonephritis. Constant leakage of urine from the vaginal cavity causes maceration of the skin of the external genitals and can provoke neurotic excoriation.
Pathology interferes with the normal course of labor and significantly increases the risk of ruptures of the soft birth canal. Like other types of urogenital fistulas, urethro-vaginal messages significantly worsen the quality of life of the patient — they interfere with normal sexual life, contribute to the development of depression, hypochondria, neuroses.
In most cases, the typical clinical picture and the association of the disease with urogynecological, obstetric or other trauma allow us to assume with high probability the presence of a urethrovaginal fistula. In doubtful cases (in the presence of point or multiple fistulas), additional studies are recommended. To choose the optimal treatment method, data on the exact localization and size of the fistula, the condition of the mucous membranes of the communicating organs are required. They are the most informative in diagnostic terms:
- Gynecological examination. Large defects are clearly visible and palpable on the front wall of the vagina when examined on a chair using vaginal mirrors. The method allows to evaluate the elasticity of soft tissues and the presence of scar deformation. To verify the opening, colposcopy and probing of the fistula canal from the external opening of the urethra are additionally used.
- The use of coloring pigments. To identify spot fistulas hidden in the vaginal folds and scars, a dye (usually methylene blue) is injected into the bladder. After urination, it can be detected on a cotton swab installed intravaginally, or you can notice drops of pigment solution on the vaginal mucosa in the area of the fistula opening.
- Endoxopic examination. Urethroscopy is one of the best solutions for obtaining detailed information about the urethro—vaginal fistula canal. With their help, the localization of the mouth of the fistula is clarified, its dimensions are determined, and the features of the morphological structure of tissues are determined. If a neoplastic process is suspected, it is easy to obtain a sample for histology through an endoscope.
- Urodynamic studies. To verify the causes of possible urinary incontinence and determine the functionality of the closure structures, intraurethral pressure profilometry and uroflowmetry are performed, filling and emptying cystometry is performed. These techniques are especially important for fistulas in the distal urethra, when it is necessary to evaluate the work of the sphincters.
Radiological methods with contrast (excretory urography, vaginography) in the diagnosis of urethrovaginal fistula are currently used extremely rarely. Pathology is usually differentiated with vesicovaginal fistulas, urinary incontinence, inflammatory diseases with a large volume of vaginal secretions (infectious colpitis, endocervicitis, endometritis). According to the indications, consultations of various specialists are prescribed.
Treatment of urethrovaginal fistula
The only method of eliminating the fistula stroke is surgical plastic surgery. Reconstruction of the urethra, especially with a significant tissue defect and a combination of pathology with partial or complete urinary incontinence, is considered one of the most difficult problems of modern urogynecology. Taking into account the severity of the disease , the following types of interventions are performed:
- Suturing of the fistula opening. While maintaining the elasticity of the surrounding tissues, localization of a small fistula in the distal urethra may be sufficient separate suturing of the urethra and vagina after their separation. Suturing of the fistula is performed through vaginal access.
- Plastic surgery of the walls of the vagina and urethra. Vaginoplasty is indicated for the detection of multiple fistulas and significant tissue deficiency. The use of flaps from the labia majora or labia minora, the anterior vaginal wall allows you to eliminate the existing defect and reduce the risk of recurrence of urethrovaginal fistula.
- Reconstruction of the fistula and sling urethropexy. If the pathology is combined with urinary incontinence, the intervention is carried out in two stages. Initially, the pathological message is eliminated by suturing or plastic surgery. After 3-6 months, a sling (loop) operation TVT-O is performed to restore urodynamics.
Regardless of the method of surgical correction, careful preparation is performed before the operation, which can last from 3 months to six months. At the preparatory stage, a complete sanitation of the genitals and urinary organs is carried out, if possible, the reparative abilities of the tissues of the vagina and urethral canal are restored. This approach minimizes the likelihood of relapse.
Prognosis and prevention
Thorough examination and preparation for surgery, the introduction of new techniques of reconstructive interventions allowed to reduce the occurrence of recurrent urethrovaginal fistula channels to 21-22%. A higher risk of recurrence is determined in women who have undergone complicated childbirth, radiation therapy, accidents and injuries.
Prevention of the disease involves the reasonable appointment of invasive procedures, compliance with the technique of urological, gynecological and obstetric operations. Careful management of labor plays an important role in preventing the disorder, especially when identifying risk factors (anatomically narrow pelvis, large fetus, rigid cervix, weakness of labor activity, discoordination of contractile activity of the myometrium, pelvic presentation).