Introduction
Cloacal anomalies are a rare congenital disorder that presents as the confluence of the genital, gastrointestinal, and urological, which exits the perineum through a single orifice. Cloacal anomalies are considered the most complex anorectal malformations and can be very challenging for pediatric urologists, gynecologists, and pediatric surgeons.
What Is the Cause of Cloacal Anomalies?
The cause is due to the failure of embryonic anorectal and urogenital channels. However, the etiology of failure remains unknown.
How Common Are Cloacal Anomalies?
Cloacal anomalies are 1 in 5000 live births, although many cloacal anomalies are diagnosed as rectovaginal fistula. Cloacal anomalies show a female predominance.
What Is the Pathophysiology of Cloacal Anomalies?
Cloacal anomalies are caused due to the failure of embryonic anorectal and urogenital channels, which separate during the sixth and seventh gestational weeks. It is also believed that the arrest of normal embryogenic processes leads to a common channel with functional and reconstructive implications later in life.
What Are the Symptoms of Cloacal Anomalies?
Prenatal diagnosis is less likely in individuals with cloacal anomalies. However, prenatal MRI (magnetic resonance imaging) and ultrasound may detect a cystic pelvic structure in the pelvis of a female, which may consist of a fluid-filled vagina (hydrocolpos). Additionally, prenatal orthopedic or renal findings make diagnosing cloacal anomalies easier.
A physical examination of a newborn obtains a definitive diagnosis by identifying a single perineal orifice, usually present posterior to the clitoris. The perineum is thoroughly examined with adequate lighting and is done by retracting the labia up and out to check for the relation of the urethra to the hymen. In cloacal anomalies, the urethra is present inside the hymen, or the anterior hymen may be absent. If the urethra is present distal to the hymen, then the cloaca is ruled out.
Further findings include diminutive and foreshortened labia minora and a clitoral head. In addition, abdominal examinations may show the presence of mass, representing a hydrocolpos seen in 40 % of the cloacal anomalies cases.
How Are Cloacal Anomalies Evaluated?
Initial evaluation of an individual with cloacal anomalies involves the identification of associated life-threatening diseases and treating the same. Cloacal anomalies often correlate with abnormalities such as anorectal, vertebral, cardiac, tracheoesophageal fistula, limb, and renal association. Early diagnosis helps in necessary management. It is advised for a thorough urologic assessment in newborns.
Functional and structural abnormalities, including renal agenesis, renal dysplasia, hydronephrosis, and horseshoe kidney, are common in individuals with cloacal anomalies and are reported in almost 90 % of the cases. Renal and urologic dysfunction account for long-term morbidity in individuals with cloacal anomalies, and early intervention and prompt treatment may improve renal health. Detecting spinal anomalies is essential as there is a high association between cloacal anomalies and tethered cords.
This is evaluated using ultrasound within the first three months after birth or magnetic resonance imaging after three months due to ossification of the coccyx and sacrum. The decision to de-tether a cord depends on urodynamics' function and imaging effects. The indications for de-tethering may vary. This results in urologic benefits, and fecal continence may vary. The sacrum is assessed using anteroposterior and sacral x-rays to detect sacral anomalies to determine the sacral ratio.
What Is the Treatment for Cloacal Anomalies?
Initial Management:
Firstly the child is stabilized, and the hydrocolpos is identified and drained, if present. A hydrocolloid is a fluid-filled vagina that anteriorly compresses the bladder at the trigone area where the ureters enter, leading to hydroureteronephrosis and obstructive uropathy. This is best evaluated using an ultrasound of the abdomen and pelvis.
Drainage may be performed using a catheter in a common channel. However, confirming if the hydrocolpos have been completely emptied is important as they may not be adequately decompressed due to the catheter. Catheterization may not be a long-term solution for all individuals, or a vaginostomy may be considered in individuals with inadequate drainage to ensure drainage of the urinary system.
In rare cases, a urinary diversion is. Surgery aims to divert the fecal stream with colostomy and mucous fistula creation. A colostomy is prioritized, and the distal segment length is used for future pull-through. A loop colostomy is not performed on the distal limb.
Treatment:
The definitive treatment for cloacal anomalies includes surgical by separating gynecologic, gastrointestinal, and urologic structures by creating a perineal opening for structures to restore the function of each system by creating a catheterized urethra. A posterior sagittal approach treated earlier the cloacal anomalies by performing posterior sagittal anerectovaginourethroplasty (PSARVUP).
In this technique, the vagina is separated from the common by urogenital separation. But this procedure leads to complications in the formation of a urethrovaginal fistula. Later urogenital mobilization technique was performed, which had risks leaving the individual with a short urethra and a bladder neck inferior to the urogenital diaphragm causing urinary incontinence. Later an algorithm was proposed which helps in retaining the urethra length. Definitive surgical repair is performed at six to twelve months of age. A posterior sagittal incision performs the repair with a laparoscopic or open approach.
What Is the Prognosis for Cloacal Anomalies?
Bowel and urinary continence in individuals with cloacal anomalies are primarily due to the length of the common channel, the degree of sacral development, and the tethered spinal cord. Individuals with a common channel greater than 3 cm, a sacral, and tethered cord of a ratio less than 0.4 may have worse functional outcomes. In addition, individuals with poor urologic and colorectal function may require bowel and bladder reconstruction.
What Are the Complications of Cloacal Anomalies?
Failure in early diagnosis may lead to acidosis, sepsis, and in severe cases, renal failure. Misdiagnosis leading to only repair of the rectal component causes a urogenital sinus. The most important complication is a urethrovaginal fistula which needs surgical intervention.
Conclusion
Cloacal anomalies are congenital disorders characterized by a confluence of the genital, gastrointestinal, and urologic systems. The etiology of cloacal anomalies remains unknown. Failure in early diagnosis may result in kidney failure. Treatment involves surgical intervention.
