Cloacas
Sagittal View of a
Typical Persistent Cloaca
|
Surgical management of a
persistent cloaca represents the most serious technical challenge in pelvic pediatric surgery.
The complex operation used to treat this defect is called Posterior Sagittal Anorectovagino-urethroplasty / PSARVUP.
The sagittal view of a typical persistent cloaca. The main characteristic of this defect is the confluence of rectum, vagina and urinary tract into a single channel.
Cloacas represent another spectrum of defects by themselves and the degree of complexity, the technical challenge, as well as the results will vary within a wide range. The spectrum of cloacas includes a variety of defects but the most frequent seen by the author are represented here.
Most Frequently Seen Types of Cloaca
|
The length of the common channel in this type of defect varies from two to three centimeters. The vagina has a good size. The muscle complex and external sphincter are located in a normal site, posterior to the single opening that these patients have in the perineum.
The single perineal orifice is usually located at the site of a normal urethral orifice. The genitalia look smaller than in a normal patient.
High Cloaca
Cloaca in which
Rectum opens High
Into Vaginal Dome
Low Cloaca
Frequent Finding
in Cloacas: Hydrocolpos
Double Vagina
and Double Uterus
|
It is very important for pediatric surgeons, pediatricians, and general practitioners to have a high index of suspicion in order to detect and diagnose these malformations early in life. Imperforate anus and small-looking genitalia on a baby girl should alert the physician to this defect.
In addition to the described abnormalities, these patients have a high incidence of associated urological abnormalities that may include:
- Hydronephrosis
- Megaureters
- Reflux
- Renal dysplasia
- Renal agenesis
- Neurogenic bladde
As seen in the case of the spectrum of anorectal malformations, the degree of sacral abnormalties and muscle deficiencies usually varies along with the height of the defect. Thus, high cloacas (long common channel) are more frequently associated with an abnormal sacrum and poor muscles.
This figure shows a "high" cloaca. The length of the common channel in this type of defect varies from three to seven centimeters and it represents a serious challenge for the pull-through of the rectum, but mainly for the vaginal repair.
If, in addition, the patient has a very small vagina, the problem becomes much more difficult because there is not enough tissue to mobilze the vagina and to suture it to the perineum. In addition to needing an abdominal approach, these patients will require some type of vaginal replacement to fill the gap between the vagina and the perineum.
The "high" cloaca patients also have a narrow pelvis, particularly the anteroposterior (AP) diameter, with a short sacrum and poor muscles. The prognosis, therefore, in this specific group is not as good as in the others.
An unusual type of cloaca is one in which the rectum opens high into the vaginal dome. In this case, a laparotomy is indicated to pull the rectum down, as described for rectobladder fistulae in males, in spite of the fact that the vagina is located rather low.
About 20 percent of the total cloacas treated by the author required an exploratory laparotomy in addition to the posterior sagittal approach in order to achieve the total repair of the defect.
In the case of a very low type of cloaca, the length of the common channel varies from 0.5 to 1.5 centimeters. This defect could also be called recto-low vaginal fistula associated with a female hypospadias.
The treatment consists of separating the rectum from the urogenital tract and locating it within the limits of the external sphincter, leaving the genitourinary portion of the defect untouched. The patient will then have a high urethral opening (female hypospadias).
Another alternative would be to separate the vagina from the urethra to achieve a complete repair which, from the functional point of view, is not absolutely necessary.
This defect has an excellent functional prognosis and therefore, while evaluating results, it must be considered as a separate group.
A frequent finding seen in cloacas is hydrocolpos, a very large vagina, distended and filled with fluid. The cause is suspected to be an obstruction to the emptying of the vagina; however, this is doubtful because we have seen vaginas without obstruction that are very distended.
Very distended vaginas most likely promote urinary tract obstruction and subsequently, frequent urinary tract infections; thus, surgical drainage of the vagina dramatically improves the urinary tract problem.
About 40 percent of the cloacas seen by the staff of the Colorectal Center have an associated hydrocolpos.
In retrospect, the presence of the hydrocolpos represents an advantage in terms of vaginal reconstructions because the surgeon can use all the extra tissue of the enlarged vagina to achieve a comfortable plasty that will allow an anastomosis between the vagina and perineum without tension.
Sometimes, the voiding pattern of these patients is such that the urine passes directly from the bladder through a short proximal urethra and into the distended vagina; subsequently during the day, the urine dribbles out constantly, stimulating urinary incontinence (pseudourinary incontinence).
The total repair of this defect may change the voiding pattern of the patient into a normal one, in cases with a normal sacrum.
Another frequent finding in cloacas is a double vagina and double uterus. Sixty percent of patients with cloacas had some form of septation of the vagina and uterus.
This may consist of a partial septum in a large vagina with one cervix and one uterus, and at the other end of the spectrum a completely separated double vagina with double uterus may be found.
Also, the uterus may be partially (bicornate uterus) or completely separated (double uterus).
During the posterior sagittal approach, the unique opportunity exists to surgically fuse together both vaginas creating a single one. So far, we have not attempted the reconstruction of both uteri.
These diagrams show some of the abnormalities associated with cloacas but in practice these patients may disclose an additional and unpredictable combination of anomalies.
For more information or to request an appointment, please contact the Colorectal Center at Cincinnati Children's.
