Keywords urethra atresia - cloaca - rectal patch
Introduction
Cloacal malformations comprise a heterogeneous group of anomalies that are considered
the most complex anorectal malformations (ARMs) in females. Cloacal malformations
are classified according to the lengths of the common channel and the urethra. This
classification constitutes the basis whereby the surgeon chooses the surgical approach,
either to do a urogenital (UG) separation or a total UG mobilization (TUM).[1 ] Despite this broad classification, each cloaca case has unique variations that can
require modification of the surgical technique to achieve an optimal reconstruction.
A thorough preoperative evaluation to identify the specific anatomy of each patient
prior to reconstruction, with collaboration between colorectal surgeons, urologists,
and gynecologists is vital to plan an individualized approach for each patient. The
case presented is a rare anatomical variation in a patient with a cloacal malformation,
urethral atresia, a small vagina, and a megarectum, and the reconstructive approach
for this patient is described.
Case Report
A 6-year-old female with cloaca who underwent colostomy, vaginostomy, and vesicostomy
as a newborn was referred to our team for reconstruction. A thorough workup was completed
and was significant for the following: The physical examination showed rudimentary
genital folds with a single perineal opening, no anal opening, and a gluteal fold
with a dimple at the site of the anal sphincter ([Fig. 1 ]). The VACTERL workup was negative except for an atretic right kidney and left grade
IV vesicoureteral reflux. Her ARM index included the cloaca, a normal spine, and a
normal sacrum with a lateral sacral ratio of 0.7, predicting good potential for bowel
control. Cystoscopy through the vesicostomy showed a small bladder with a closed bladder
neck, normal ureteral orifices, and no identifiable urethra. A cloacagram showed an
atretic common channel, a single small and high vagina, and a rectum below the pubococcygeal
(PC) line ([Fig. 2 ]).
Fig. 1 Physical exam reveals rudimentary genital folds, which, when retracted, reveal a
small, single perineal opening. There is no anal opening, but there is a gluteal fold
with a dimple at the site of anal sphincter.
Fig. 2 The cloacagram shows an atretic common channel, an atretic urethra, a single small
vagina, and a rectum below the pubococcygeal line.
The patient underwent a posterior sagittal anorectovaginourethroplasty in prone position.
The vagina was small and not amenable to vaginal pull-through. The patient had a megarectum,
which allowed for a vaginoplasty using a rectal patch. For the rectal patch creation,
we cut a rectangle from the anterior rectal wall based on the two perforating mesenteric
vessels on either side ([Fig. 3 ]). This created a well-perfused rectangle which could then be sewn to the open vagina,
while tubularizing it. We made sure the distal extent reached to the area of the clitoris
and was healthy and viable ([Fig. 4 ]).
Fig. 3 For a rectal patch, the megarectum is divided longitudinally with care to preserve
its blood supply.
Fig. 4 The neovagina is reconstructed using the rectal patch, shown here being tubularized
over a Hegar dilator. The patch was sutured to the wall of the vagina circumferentially.
A 24-French Foley catheter, used for calibration of the rectoplasty, is seen in the
rectum.
The rectoplasty was done by tubularizing the remnant rectum over a 24-French Foley.
An ischiorectal fat pad was used as a cushion between the neovagina and the neorectum.
The perineal body reconstruction and introitoplasty were performed in supine position.
The urethra was not amenable to reconstruction, therefore the vesicostomy was preserved,
with a plan for a future Mitrofanoff. Piperacillin/tazobactam was given as a broad-spectrum
prophylactic antibiotic and was continued until the intraoperative urine culture returned
as negative. The recovery in the postoperative period was unremarkable. As the procedure
had no intra-abdominal component, the patient's diet was resumed immediately following
surgery.
The patient is planned for a future colostomy closure with Malone appendicostomy to
gain social fecal continence and creation of a continent catheterizable channel for
urine (Mitrofanoff), to attain urinary continence.
Discussion
Cloacal malformations are classified according to the common channel and urethral
lengths. This is a broad classification and does not take into account some rare variations
such as the case described here. Generally, patients with a shorter common channel
length (less than 3 cm) and a longer urethral length (more than 1.5 cm) are amenable
to a TUM. Those with a short urethra (less than 1.5 cm) or with common channel length
more than 3 cm must undergo a UG separation.[1 ] In this case, the patient had no urethra or common channel, creating a considerable
challenge for reconstruction.
Urethral atresia is rarely mentioned in the literature as most of these patients die
in utero or are stillborn. The urethral obstruction in fetuses without drainage of
urine leads to oligohydramnios, and pulmonary and renal failure, making this malformation
rarely compatible with life. Most of the surviving neonates born with this anomaly
have some channel to drain urine antenatally, either through a patent urachus, a vesicocutaneous
fistula, a vesical perforation, development of urinary ascites by backflow of urine
through the fallopian tubes, or one that is created through an antenatal surgical
intervention, like a vesicoamniotic shunt.[2 ] In the presented case, the presence of a communication between the bladder neck,
vagina, and rectum provided a drainage system for urine into the bowel.
Urethral atresia is reported to be associated with prune belly syndrome. One theory
suggests that the distended bladder disrupts the development of the abdominal wall
musculature.[3 ] However, an abdominal wall defect was not observed in this patient. In the newborn
period the urinary system rarely needs drainage, and ureteral obstruction is almost
always due to compression at the trigone by a hydrocolpos. Drainage of the hydrocolpos,
usually achieved by catheterization of the common channel almost always succeeds in
reducing the hydronephrosis. However, in the case of urethral atresia, the urinary
system must be diverted, as was done here using a vesicostomy.
Determining the ideal procedure for the reconstruction in patients with a cloacal
malformation is always challenging, but this is particularly true for those with a
rare association with urethral atresia, such as in this case. This scenario is discussed
in the literature in several instances. González et al reported six male patients
with urethral atresia, of whom two patients underwent successful dilation of the urethra
followed by rupture of the urethral membrane, and urethral continuity was able to
be restored. Continent catheterizable conduits to the bladder were required in four
patients, of whom three had undergone unsuccessful attempts at reestablishing urethral
continuity by open urethroplasty.[2 ] Reinberg et al reported a case of a female patient with urethral atresia, vaginal
atresia, and imperforate anus. She underwent a neobladder reconstruction, a urethral
reconstruction using appendix, a vaginoplasty, and an anoplasty. The patient was continent
of urine at age 8 and had normal renal function.[4 ]
Before constructing a continent catheterizable channel, a Mitrofanoff, the family
should prove their commitment to frequent catheterization of the infant. Patients
without this level of social support should have the Mitrofanoff procedure delayed
until they are capable of self-catheterization. In this patient's case, the decision
was made to preserve the vesicostomy to drain the urine until the family was prepared
to commit to the necessary frequency of catheterizations.
Although this patient has a good ARM index, which predicts a good prognosis for bowel
control, the possibility of doing a Malone appendicostomy was discussed. This patient
is school age, and the Malone appendicostomy can help this patient to gain social
continence and practice gaining control of her anal sphincters using the Malone. This
is ideally done at the time of colostomy closure, coordinated with urology team if
a Mitrofanoff is needed, to minimize the number of surgical interventions for the
patient and to decide how the appendix is divided between the Malone and the Mitrofanoff.
Surgeons operating on complex ARMs, especially cloacal malformations, should be familiar
with the different techniques to reconstruct the vagina, to be prepared for when the
vagina does not have enough length to reach the perineum.[5 ] In our center, we do the vaginal reconstruction at the time of the initial surgery,
to avoid multiple surgeries on the perineum, which will weaken the area. This would
have been more difficult in this patient given the scar tissue and adhesions we had
to go through. Ideally, the native vagina is used and bowel replacement is avoided.
There is no strict definition on what is a high or low vagina, but for this patient,
the vagina ended at the level of the PC line on cloacagram, which we consider as a
high vagina. In this patient, it was also small, because it is not dilated from a
previous hydrocolpos. For these reasons, it was unlikely it would have been able to
be mobilized to reach the perineum without tension.
In such rare cases, in order to bridge the gap of a vagina that does not reach the
perineum, the options include vaginal replacement using small bowel, large bowel,
or rectum. Using a rectal patch is a good option to reconstruct the vagina when the
rectum is large enough to be used for both the vaginoplasty and the rectoplasty, as
in this patient's case, due to her megarectum.[6 ] A large rectum does not have normal motility and thus, reducing its size might be
helpful to approach a more normal rectal capacity. Having a more normal-sized rectum
will help to optimize the patient's motility and improve their chances for bowel continence.
The rectum in this case was reconstructed by reducing its size and tubularizing it
over a 24-French Foley catheter to mimic a normal rectum.
Conclusion
This case illustrates the importance of careful identification of the precise anatomy
in each patient with cloaca and highlights the importance of having different reconstructive
techniques at the surgeon's disposal to optimize the pelvic reconstruction, tailored
to the particular patient's needs.
