Introduction:
Anorectal malformations (ARM) can appear in different patterns. The vestibular or rectovestibular fistula is one of the most common congenital anorectal malformations seen in female patients. This disorder has an abnormal connection between the rectum and the vulvar vestibule (outside the vagina - reproductive part in females). It results in the passing of gas or feces through the vagina.
What Are Anorectal Malformations?
Anorectal malformations are the congenital disabilities of the anorectal region in which the anus and rectum do not develop properly. These disorders can occur in 1 in 4,000 newborns and can be mild to complex deformities.
The anorectal malformations can have different abnormalities, such as -
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Narrowing of the anal tract or passage.
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A thin membrane might be present over the anal opening.
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The rectum and anus may not be connected (imperforate anus).
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The rectum may connect to the urinary tract or the reproductive system abnormally through a passage called a fistula.
What Are the Causes of Anorectal Malformations?
In the fetus stage, different organ systems develop in maturing in the womb or uterus of the mother. The lower end of the intestinal tract forms early in pregnancy. The lower part of the large intestine and the urinary tract start as the mass of cells. The formation of this part of the intestine and urinary tract should happen in the first three months of the pregnancy. During this phase, the rectum and anus break away from the urinary tract and form properly.
In some cases, these steps do not happen chronologically, and the rectum or anus may develop normally, leading to anorectal malformations. Moreover, in most cases, the reason for this is unknown.
Who Is at Risk of Developing Anorectal Malformation?
Anorectal malformations are commonly seen in some genetic conditions present at birth. These include -
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VACTERL association (VACTERL stands for vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula, renal anomalies, and limb abnormalities.)
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Digestive system problems.
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Urinary tract problems.
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Spinal problems.
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Down syndrome (a genetic disorder of chromosome 21 leading to developmental and intellectual delays).
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Townes-Brocks syndrome (a genetic condition that affects several parts of the body, such as the anus, kidneys, ears, arms, and legs
What Are the Types of Anorectal Malformations?
The malformations are usually classified based on where the rectum ends within the abdomen and the presence of a fistula (an abnormal channel that develops between organs). Some of the malformations are listed below, which can appear by themselves or in combination, such as -
1. Malformations Found in Both Males and Females -
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Anorectal Malformation Without Fistula - The anal opening is either absent or is present abnormally.
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Rectal Atresia and Stenosis - The anus or rectum are very narrow to allow the passage of stools.
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Rectoperineal Fistula - The rectum gets abnormally connected to the perineum (an area between the anus and genitals).
2. Malformations Found in Males -
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Rectobulbar Urethral Fistula and Rectoprostatic Urethral Fistula - The rectum gets abnormally connected to the urethra (the tube responsible for taking urine out of the body through the genitals).
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Recto-Bladder Neck Fistula - Rectum is connected to the bottom of the urinary bladder, where the urethra begins.
3. Malformations Found in Females -
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Rectovestibular Fistula or Vestibular Fistula - The rectum connects just outside the vagina.
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Rectovaginal Fistula - A rare malformation in which a connection is formed between the rectum and the vagina.
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Cloaca - The rectum, vagina, and urinary tract are combined into one unit.
What Are the Symptoms of Vestibular Fistula?
Some of the most common symptoms of vestibular fistula include -
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Passing of feces, gas, and pus through the vagina.
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Repeated urinary tract or vaginal infections.
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Discharge from the vagina with a foul smell.
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Irritation around the infected area.
Some additional symptoms that the patient may notice include -
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Inflammation of the vulva shortly after giving birth.
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Leakage of feces from the vaginal vestibule.
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Adult patients may experience pain during sexual intercourse.
How Are Anorectal Malformations or Vestibular Fistula Diagnosed?
A physical examination of the anus and vagina is done to check the opening and position. The doctor might perform several tests to understand the problem better and develop a long-term plan. Some tests to diagnose this condition include -
X-rays -
Abdominal X-rays are taken to see how far the rectum reaches and to check for any problems in the anorectal area. Distal colostogram is another type of X-ray that helps the surgeon identify where the rectum is located and where the fistula joins other organs in the body.
Ultrasounds -
Ultrasounds can be done to better look at the urinary tract and the kidneys. Any kind of blockage or abnormal fluid buildup can be seen through the ultrasound.
MRI-
Magnetic resonance imaging can also be done to help diagnose this condition.
What Is the Treatment for Vestibular Fistula?
Generally, the less complex malformations can be repaired with one surgery, and children often gain good bowel control. However, complex malformations require more procedures and usually face more challenges in gaining bowel control.
The treatment for vestibular fistula revolves around repairing or reconstructing the rectum within the sphincter muscles and pelvic floor for long-term prognosis. After determining the position of the fistula by doing X-rays, surgery is planned. If the rectum is high in the pelvic floor or the connection is closer to the bladder, the surgery is LAARP (laparoscopic-assisted anorectoplasty). If the rectum is closer to the bottom, then a PSARP (posterior sagittal anorectoplasty) procedure will be done.
LAARP (Laparoscopic-assisted Anorectoplasty) -
Laparoscopy is also called keyhole surgery, and in the case of LAARP, the surgeon releases the rectum through the abdomen and repairs the connections; after that, the surgeon makes a midline incision in the perineum and rebuilds the rectum in the pelvic floor and sphincters.
PSARP (Posterior Sagittal Anorectoplasty)-
In this procedure, an incision is made in the midline of the perineum, and the rectum is located and free from all attachments. If there is a connection of the fistula to the urethra or vagina, then it is repaired by this procedure after the rectum is reconstructed to provide a better prognosis in the long term.
Conclusion:
Vestibular fistula is a rare condition that can be treated only with the help of surgeries. The long-term prognosis depends upon the complexity of the malformation. However, with early diagnosis and appropriate medical intervention, individuals can effectively manage this condition and experience improved quality of life. Understanding the causes, symptoms, and treatment options is crucial for both patients and healthcare professionals, as it empowers them to navigate the complexities of vestibular fistula and make informed decisions regarding care and management.
