What is Cloacal Malformations?
Cloacal malformations are uncommon birth defects where the digestive, reproductive, and urinary systems merge and exit the body through one hole. This condition is viewed as one of the most complicated forms of anorectal malformations – a group of disorders affecting the rectum and anus. It presents a significant challenge to pediatric surgeons, urologists, and gynecologists who specialize in treating children.
What Causes Cloacal Malformations?
We still don’t know exactly what causes these conditions.
Risk Factors and Frequency for Cloacal Malformations
Cloacal anomalies, which are medical disorders that only appear in females, occur approximately in 1 out of 50,000 live births. However, the actual number might be higher because these anomalies are sometimes misidentified as a different issue called a rectovaginal fistula.
Signs and Symptoms of Cloacal Malformations
Cloaca is a condition that is rarely diagnosed before birth, though prenatal ultrasounds or MRIs might show a fluid-filled structure, called a hydrocolpos, inside the pelvic area of a female fetus. This becomes more probable if there are additional issues with the baby’s skeletal or urinary system identified during prenatal examinations.
A conclusive diagnosis of cloaca is made after the baby is born, by examining the newborn’s perineal area (the area between the genitals and the anus). If there is a single opening present, usually located behind the clitoris, then the baby may have cloaca.
This examination should be conducted meticulously with good lighting. One must lift and spread apart the labia to see the connection between the urethra (where urine comes out) and the hymen. In cases of cloaca, the urethra is found inside the hymen, or the front part of the hymen is missing. If the urethra is located beyond the hymen, then the baby doesn’t have cloaca.
- Other observable signs may include smaller than usual labia minora and a hood over the clitoris.
- Examination of the lower abdomen may reveal the presence of a mass, likely a hydrocolpos, which is seen in about 40% of patients with cloaca.
Testing for Cloacal Malformations
When a patient is identified with a cloacal malformation, initial steps involve determining and addressing any connected life-threatening anomalies. Cloacal malformations are often linked with anomalies in certain structures like the vertebral column, heart, limbs, and the urinary and digestive systems. If a diagnosis is confirmed, it’s essential to seek early advice from a pediatric surgeon or a pediatric urologist with experience in managing this condition.
In early infancy, it’s vital to carry out a detailed assessment of the urinary system. Abnormalities in the structure and function of this system, including kidney malformations or anomalies, are common in patients with a cloacal malformation and are detected in 90% of cases. Early recognition of these anomalies and swift intervention can help maintain long-term kidney health, as cloacal malformations could contribute to significant long-term health effects due to urinary and kidney dysfunction.
Spinal anomalies like a tethered spinal cord are also highly associated with cloacal malformations. Therefore, it’s important to identify these early on. This can be done using ultrasound in the first three months or an MRI scan after three months. The decision to treat a tethered cord is based on imaging and the impact on function determined via a urodynamic test. Though the benefits on urinary health from de-tethering are clear, its direct impact on bowel control hasn’t been clearly demonstrated yet.
Examining the sacrum, a bone at the base of the spine, is also important. This can be done using x-rays taken from the front (anteroposterior) and side (lateral) to look for anomalies. The sacral ratio, a measure of the bone’s length, can be a valuable marker for developmental progress of key muscles and nerves needed for bowel and bladder function. This information can help doctors discuss the child’s future health prospects with families. However, for accurate calculations, it’s crucial to use lateral x-ray images, as front-facing images can be skewed by the tilt of the pelvis.
Treatment Options for Cloacal Malformations
When a child has been stabilized, the first aim is to identify and remove a hydrocolpos, if present. This term refers to a vagina filled with fluid that puts pressure on the bladder and the tubes where the urine enters, leading to kidney swelling and blockage in the urinary system. This condition can be best understood by using an ultrasound for the abdomen and pelvis. Hydrocolpos can be drained by placing a catheter into the common channel; however, one needs to make sure it has been drained properly since the tube could enter either the bladder or a single part of the vagina leading to incorrect drainage. For some patients, a long-term strategy won’t just be catheterization; it might have to include creating a drainage through the vagina, especially if the fluid begins to buildup again or doesn’t initially drain adequately. If this doesn’t succeed in emptying the bladder, urinary redirection can be performed when creating the colostomy with a vesicostomy or tube placement above the bladder.
The early surgical goal is to reroute the feces with a descending colostomy with a mucus fistula creation. The placement and length of the colostomy is important as this part of the bowel will be used for the future reconstruction. A loop colostomy isn’t recommended because it remains connected with the urinary system; if stool leaks, it risks contaminating the urinary system and causing an infection.
Proper surgical repair necessitates identifying and measuring several pelvic structures. This includes the length of the channel shared by the urinary, gynecological, and digestive systems, the length of the urethra, the presence and length of a vagina, whether or not there’s a split in the vagina, the presence of a cervix and its duplications if any, and the precise position of the rectum and where the rectal opening is in relation to the pubococcygeal (PC) line.
No definitive imaging procedures have been standardized yet, but endoscopy and 3D imaging are useful in assessing the patient’s anatomy. Some experts believe MRI will have a more significant role in the future.
The ultimate treatment for cloaca is surgical, aiming to separate the digestive, gynecological, and urinary structures and create an opening for each one in the pelvic region. The goal is to optimize the function of each system and create a urethra that can be easily catheterized. Surgeons make sure to separate the vagina from the common channel gently to avoid creating a new connection between the vagina and urethra due to poor blood supply, which can lead to complications. Sometimes the vagina and urethra are moved as a unit to avoid damaging the tissue between these two structures. Still, this procedure also risks creating an urethra that is too short and a urinary incontinence. In such a case, a patient-specific approach has to be considered based on the lengths of the common channel and native urethra, aiming to achieve optimal urinary control.
Definitive repair is typically done between 6 and 12 months of age. The specifics of the repair are complex and depend on the patient’s anatomy. They often involve a cut along the back, and may also include a laparoscopic or open approach to mobilize a high rectum or vagina as needed by the patient’s anatomy.
What else can Cloacal Malformations be?
When trying to diagnose cloaca, a complex birth defect in girls, doctors also need to consider other related but less severe conditions. These conditions are various subtypes of ARM (Anorectal malformations), such as a rectovaginal fistula (an abnormal connection between the rectum and the vagina), a rectovestibular fistula (an abnormal connection between the rectum and the vestibule of the vagina), and an imperforate anus with no fistula (a situation where the anus is either blocked or missing), with or without vaginal atresia (a condition where the vagina is absent or closed).
By carrying out a thorough physical examination, doctors can then identify whether the patient has cloaca, or one of these less severe conditions. It’s essential to distinguish between these because the treatments required can differ.
What to expect with Cloacal Malformations
In patients with cloacal malformations, the ability to control urination and bowel movements primarily depends on the length of the common channel and the presence of other deviations, especially the development of the sacral bone and a condition called a tethered spinal cord. Those with a common channel longer than 3 cm, a tethered spinal cord, and a sacral ratio less than 0.4 often have worse functional results.
These abnormalities in the spine and sacrum are typically found in patients with more complex cloacal malformations. However, how much the spine and sacrum contribute to these functional outcomes is not fully understood in patients with cloaca. In some cases, patients with poor bowel and bladder function might need surgery to reconstruct these organs later in their childhood. These procedures can be done at the same time.
Possible Complications When Diagnosed with Cloacal Malformations
Not correctly identifying a condition called ‘cloaca’ in newborns may miss a form of urinary tract obstruction, which is caused by a condition called ‘hydrocolpos.’ This situation could lead to serious illnesses like sepsis or acidosis and, in severe cases, can result in kidney failure. If doctors misdiagnose cloaca in newborns, they might only fix the rectal malfunction, leaving an ongoing issue called a ‘urogenital sinus.’ A significant concern after surgery is the formation of a complication called a ‘urethrovaginal fistula,’ which is a hole that develops between the vagina and the urethra. This condition needs further surgical repair if it’s close to the urinary sphincter.
Common Issues caused by Misdiagnosis of Cloaca:
- Urinary tract obstruction
- Sepsis (bodywide infection)
- Acidosis (high acid levels in the body)
- Kidney failure
- Persistent urogenital sinus (an ongoing issue with the urinary and genital organs)
- Urethrovaginal fistula formation (an abnormal hole between the vagina and the urethra)
Recovery from Cloacal Malformations
After surgery, a Foley catheter, which is a kind of tube is typically kept in place for about 2 to 4 weeks to help with urination. About a month after the PSARVUP procedure, doctors conduct an exam under anesthesia. During this exam, the Foley catheter can be removed to make sure the urethra can be accessed for needed intermittent catheterization. For some patients, long-term urinary assistance might be required. This could be due to various reasons including a long common channel, poor sacrum, and a tethered cord. In such cases, alternative measures, like a tube placed either in the bladder or above the pubic bone, might need to be considered.
Doctors also examine the anus to check the healing progress of the perineal body and anoplasty. If healing is satisfactory, the anus can be gradually enlarged with a tool called a Hegar dilator. The aim is to increase the size weekly until it reaches the target size based on the patient’s age. Once the desired size is achieved, the colostomy – a surgical procedure that brings one end of the large intestine out through the abdominal wall – can be closed.
Patients with cloacal malformations would need constant checks of their kidney function due to a high risk of kidney impairment. Indeed, in some cases, the risk of kidney failure can be as high as 50 percent.
At the time of closing the colostomy, a regular plan to empty the bowels should be started. This helps to avoid enlargement of the rectosigmoid colon (the part of the large intestine just above the rectum) which can make toilet training difficult. If a patient does not succeed in toilet training, a specialized plan may need to be implemented to establish a laxative or enema routine that can help the child maintain cleanliness and normal underwear usage.
Before the patient hits puberty, counseling on gynecological matters should be offered, taking into consideration the patient’s unique anatomy. It should be ensured that the vagina is developed well enough to allow for menstrual flow. Before the patient becomes sexually active, an exam should be done to ensure the vagina is suitable for sexual intercourse. It’s important to note that despite these conditions, patients can become pregnant, though Caesarean sections are generally the preferred method of delivery.
