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Cloacal Exstrophy
15
TedLee andJosephBorer
Introduction
Cloacal exstrophy, also referred to as omphalocele-exstrophy-imperforate anusspinal defects syndrome, is the most severe form of exstrophy-epispadias complex.
Although cloacal exstrophy was initially described in 1709, the rst case of longterm survival following successful staged reconstruction was reported in 1960 [1,
2]. Historically, high prevalence of malnutrition, sepsis, and renal failure resulted in
elevated infant mortality rates. Advances in neonatal management and surgical
reconstructive techniques have resulted in improved life expectancy, with survival
rates now approaching nearly 100% [3]. Patients with cloacal exstrophy require
lifelong individualized care to optimize nutritional status and renal function. There
has been a growing emphasis on long-term quality-of-life issues, such as urinary
and fecal continence, health related quality of life, and sexual function [4].
Supplementary Information The online version contains supplementary material available at
https://doi.org/10.1007/978- 3- 031- 91238- 2_15.
T. Lee (*)
Department of Urology, Boston Children’s Hospital, Boston, MA, USA
e-mail: ted.lee@childrens.harvard.edu
J. Borer (
Department of Surgery, Harvard Medical School, Boston, MA, USA
e-mail: joseph.borer@childrens.harvard.edu
© The Author(s), under exclusive license to Springer Nature
Switzerland AG 2025
A. R. Shukla, R. S. Joshi (eds.), Bladder Exstrophy and Epispadias,
https://doi.org/10.1007/978-3-031-91238-2_15
*)
241
242
T. Lee and J. Borer
Epidemiology
The prevalence of cloacal exstrophy is estimated to be 0.5–1 per 100,000, but the
true incidence may be higher due to the frequency of undiagnosed omphaloceleexstrophy-imperforate anus-spinal defects (OEIS) syndrome in stillbirths [5–7]. In
contrast to the clear male predominance witnessed in classic bladder exstrophy and
epispadias, there is conicting information on sex differences in cloacal exstrophy
incidence [5, 8, 9]. Higher incidence in conjoined and monozygotic twins and recur-
rence within families suggest a genetic contribution to cloacal exstrophy development [10–15].
Embryologic Etiology
A number of theories have been proposed to explain the embryologic origins of
exstrophy-epispadias complex. The most well-known theory is cloacal membrane
overdevelopment that prevents medial migration of the mesoderm. This results in
eventual rupture of the cloacal membrane due to absent mesenchymal support. If the
rupture of the cloacal membrane occurs early on in gestation before the presence of
the urorectal septum, this results in a lateral entero-vesical stula seen in cloacal
exstrophy. Conversely, if the rupture of the cloacal membrane occurs later in development after medial migration of the mesenchyme in the anterior abdominal wall
but not the urethra, it results in epispadias [16, 17]. Other theories include abnormal
fusion of the genital hillocks caudal to the cloacal membrane, caudal insertion of the
body stalk resulting in failure of interposition of the mesenchymal tissue in the
midline, and maldevelopment of the bony pelvis [17–19].
Prenatal Findings
Cloacal exstrophy can be diagnosed with ultrasonography or magnetic resonance
imaging during the fetal period. Major diagnostic criteria (>50% of cases) are nonvisualization of the bladder, large midline anterior wall defect or cystic anterior wall
structure, omphalocele, and lumbosacral anomalies. Minor criteria (<50% of cases)
are lower extremity defects, renal anomalies, ascites, widened pubic arches, a narrow thorax, hydrocephalus, and a single umbilical artery [20]. Fetuses affected by
cloacal exstrophy may be distinguished from those with classic bladder exstrophy
due to concomitant ndings involving the gastrointestinal tract and neural tube.
Bladder exstrophy and cloacal exstrophy may also be differentiated by the location
of the umbilical cord insertion relative to the abdominal wall defect. An inferior
insertion is suggestive of cloacal exstrophy [21].
Prenatal diagnosis of cloacal exstrophy is essential for proper preoperative planning and neonatal management given the severity of comorbidities associated with
this condition. Prenatal diagnosis also provides an invaluable opportunity for
repeated education, counseling, and preparation for families and caregivers [22].
Omphalocele
Intussuscepted
15 Cloacal Exstrophy
243
Reported prenatal diagnosis rates of cloacal exstrophy over the past two decades
from tertiary hospitals in North America range between 78% and 89%. This is signicantly higher than those reported from earlier time periods, which is likely due
to the frequency of prenatal ultrasonography, the quality of the ultrasonography
utilized, and the level of expertise of the ultrasonography technician and radiologists [23, 24].
Phenotypic Characteristics andAnatomic Anomalies
Cloacal exstrophy is characterized by exstrophy of the urinary bladder and cecal
plate through an abdominal wall defect, anal atresia, hypoplasia of the colon,
omphalocele, and anomalous genitalia. The bladder plate is divided in half by the
cecal (hindgut) plate. The prolapse or intussusception of the terminal ileum from the
exstrophied cecal plate is referred to as the “elephant’s trunk deformity.” The lateral
appendiceal appendages are commonly coined as the “tusks on the face of the elephant” (Fig.15.1) [25, 26].
Urinary
Abnormalities of the kidneys include renal agenesis, renal ectopia, malrotation, collecting system duplication, congenital cysts, ureterovesical junction obstruction,
and vesicoureteral reux. Ureteral atresia and bladder duplication have also been
Umbilical
Stump
Right
Hemibladder
Hemiscrotum
Small-bowel
Fig. 15.1 Phenotypic characteristics of cloacal exstrophy
Left
Hemibladder
Cecal Plate
Hemiglans
244
described [27]. In addition to congenital renal anomalies, the upper tracts are at risk
of damage from high-pressure bladder dynamics and pyelonephritis. This is evidenced by baseline renal volumes being similar between those with and without
cloacal exstrophy [28]. The prevalence of pelvic ectopic kidney ranges from 16% to
30%. Acute renal dysfunction in pelvic ectopic kidneys is of particular concern during bladder closure due to an abrupt increase in abdominal/pelvic pressure following pubic bone approximation during second-stage cloacal exstrophy closure (e.g.,
compartment syndrome) [29]. Vesicoureteral reux has been reported in 50–60%
following reconstruction and may need to be addressed surgically in the setting of
repeated upper tract infections [30].
T. Lee and J. Borer
Gastrointestinal
Congenital short bowel syndrome has been observed in up to 25% of patients.
Malabsorption could exist despite sufcient bowel length. This underscores the
importance of ileal and colonic preservation, especially at an early age. Other anomalies include intestinal duplications (including of the appendix, ileum, and colon),
ectopic perineal anus, malrotation, and duodenal atresia [31–33]. Preservation of
the appendix or appendiceal appendages during the initial reconstructive stages is
preferred for potential future use as a catheterizable channel. Omphaloceles need to
be carefully assessed prior to surgical reconstruction, as rupture requires immediate
intervention.
Neurologic
Nearly all cloacal exstrophy patients have underlying spinal dysraphisms, the
majority of which are closed. As a result of the closed spinal defect, the prevalence
of hydrocephalus is much lower compared to rates within the spina bida population. The most common defects are spinal lipoma, followed by terminal myelocystoceles. Other defects include myelomeningocele, low-lying conus with tethered
cord/fatty lum, diastematomyelia, and meningocele [34, 35]. Intracranial abnormalities, including Chiari malformation, hydrocephalus, and craniosynostosis, may
be present [36].
Musculoskeletal
Bony anomalies of the pelvis include externally rotated anterior and posterior
pelvis, acetabular retroversion, and diastasis of the pubic symphysis. Pubic diastasis, which is frequently greater than 6cm, can pose a challenge during surgical
reconstruction. Staged approximation may be needed to help approximate the
15 Cloacal Exstrophy
pubic rami gradually, perhaps reducing the risk of pelvic compartment syndrome due to abrupt closure of the pelvic ring [37]. Hip dysplasia is common
(16%); therefore, routine physical examinations and plain lm X-rays should be
performed on newborns [38]. Reported lower limb malformations include clubfoot, equinovarus deformity, and anomalies of the digits. Reported vertebral
anomalies include scoliosis, kyphosis, hemivertebrae, sacral anomalies, and
duplication [39].
245
Genital
The penis is often separated into two hemi-phalluses with wide division of the scrotum [40]. Intravesical location of the phallus can be present [41]. Cryptorchidism is
common. Absence and duplication of the vas deferens have been described but are
not the rule [39, 42].
The clitoral halves are separated with wide division of the labia. Uterus didelphys and other fusion anomalies of the Müllerian duct structures are seen in up to
87% of cloacal exstrophy females. Vaginal agenesis occurs in one-third of cloacal
exstrophy females. Vaginal duplication, agenesis, atresia/hypoplasia, and lateral
displacement are common. Cervical and ovarian duplication are also reported
[42, 43].
Management
Neonatal
In addition to a detailed physical examination, baseline laboratory tests should be
obtained (CBC, BMP, blood type). Karyotyping should be considered if sex is not
clear on examination. Once stabilized, the umbilical cord should be ligated with a
suture instead of an umbilical clamp to prevent abrasion to the bladder or cecal
plate. Optimal hydration and nutrition should be established as soon as possible.
In addition to breastfeeding and/or enteral feeds, total parenteral nutrition is often
necessary to optimize nutritional status. The exposed omphalocele, bladder, and
bowel should be covered with occlusive plastic wrap (Tegaderm™) or a hydrated
silicone gel dressing (Mepitel®) to keep mucosal surfaces moist [44]. A two-layer
dressing may be employed, where the rst covering directly on the bladder mucosal surface includes a small hole through which the prolapsed ileum segment is
passed. A second supercial dressing covers and protects the prolapsed ileum
from diaper abrasion. This second layer of dressing may also be used to help
approximate the fascia in the midline and reduce the omphalocele defect. The
goal of this dressing technique is to separate the stool from the urine and bladder
mucosal surface.
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T. Lee and J. Borer
Initial imaging studies include ultrasound of the abdomen and spine as well as
abdominal/pelvic plain lms. Sonographic examination allows the evaluation of the
upper urinary tract, internal genital structures, and spinal cord. Magnetic resonance
imaging of the spine is typically performed prior to surgical intervention, and the
abdomen/pelvis may be added if anatomy remains unclear following
ultrasonography [45].
Surgical Reconstruction
Broad goals of surgical reconstruction include (1) closure of the omphalocele, separation of the cecal plate from the bladder halves, approximation of the posterior
bladder halves in the midline, tubularization of the cecum, and incorporation of the
hindgut into the gastrointestinal tract via an end colostomy; (2) closure of the exstrophic bladder, approximation of the pubic rami, and genital reconstruction. When
patients and families are ready, surgical reconstruction can be performed to achieve
social continence. Additional surgical interventions that may be necessary are repair
of spinal dysraphism and reconstruction of Müllerian organs prior to menarche.
Most centers have moved from a single-stage reconstruction (closure of the bladder at the time of initial reconstruction) to a staged approach. A staged approach
appears to increase the chances of successful primary bladder closure compared to
the single-stage approach. Under optimal conditions, a one-stage closure may be
considered [47].
15 Cloacal Exstrophy
247
Stage 1: Omphalocele Repair, Cecal Plate Tubularization, Hindgut
Terminal Colostomy, Reapproximation ofBladder Halves
The timing of initial surgical intervention is dependent on a multitude of factors,
including medical stability, nutritional status, and infant size. Important anatomic
factors contribute to this decision, including size and status of the omphalocele
(e.g., rupture), size of the cecal and bladder plates, and open or closed spinal
dysraphism.
Historically, surgery was performed within 72h of life to minimize the risk of
omphalocele rupture, urinary tract infection, and metabolic issues secondary to
colonic mucosa being exposed to urine. However, the ventral abdominal closure and
genitourinary/gastrointestinal reconstruction can be safely delayed if stool and urine
can be separated from the bladder surface and bowel surface, respectively. The
omphalocele should also be carefully monitored given the risk of rupture. Attempts
may be made to passively reduce the ventral wall fascial defect using dressings prior
to initial reconstruction as demonstrated above. This may help prevent worsening of
ventral abdominal defect, which may increase the risk of abdominal compartment
syndrome at the time of closure. Delay of reconstruction may allow for growth,
improvement of nutritional status, and closure of an open neural tube defect [46].
Following careful exam under anesthesia, ureteral catheters are positioned in the
ureteral orices and secured prior to dissection. The omphalocele dissection begins
superiorly, and the omphalocele membrane is frequently removed. Following ligation of the umbilical vessels, the bladder plates are separated from the adjacent skin.
The medial cecal plate is separated from the two lateral bladder plates to be utilized
in the gastrointestinal tract. The bladder halves are approximated in the midline.
Inguinal hernias should be repaired if found. The exstrophied cecal plate is then
tubularized and placed in continuity with the terminal blind-ending hindgut. The
most distal portion of the hindgut is then exteriorized and matured as an end colostomy. Another option may be to retain the cecal plate with the bladder plates at the
time of initial surgical reconstruction to maintain the congenital enterocystoplasty
or “auto-augment” [48]. However, there are concerns that not incorporating the
cecal plate within the gastrointestinal tract during this initial period may result in
shortened bowel length and compromised water resorption. Efforts must be made to
preserve bowel segments and appendiceal appendages, which can be useful for
future bowel, bladder, or vaginal reconstruction.
Creation of an end ileostomy is no longer recommended due to the increased risk
of malnutrition and gastrointestinal complications [49]. Leaving the hindgut in continuity with the urinary tract within the pelvis results in complications such as
hyperchloremic acidosis, urinary tract infections, failure to thrive, sepsis, dehydration, and TPN dependence. The separation of the hindgut from the urinary tract,
dissection of the entire hindgut from the pelvis, creation of gastrointestinal continuity, closure of ileostomy, and creation of colostomy at a later date in patients initially managed this way can improve upon these morbidities. This surgery is referred
to as “hindgut rescue” [50].
248
T. Lee and J. Borer
The omphalocele is ideally completely repaired. However, very large omphaloceles may be left intact due to lack of intra-abdominal domain that can result in
abdominal compartment syndrome. In such cases, staged repair of the omphalocele
with a silo may be necessary. A biosynthetic patch may be utilized to bridge the
“gap” between the two lateral leaets of the fascia, although this results in a large
ventral diastasis postoperatively [44, 45].
Stage 2: Bladder Closure, Reconstruction oftheExternal
Genitalia, Pubic Rami Approximation withOsteotomies
The patient is now left with a single exstrophied bladder plate. The exposed mucosa
must be protected as previously described. The timing of the second-stage repair is
typically between 6 and 24months of age but ultimately dependent on the overall
nutritional status and growth of the patient. Prior to repair, the pubic diastasis must
be carefully evaluated. The pubic rami need to be reapproximated at the time of
bladder closure to reduce tension off the anterior abdominal soft tissue and reconstructed bladder. To gain pelvic bone mobility for adequate reapproximation, osteotomies are typically required. Osteotomies decrease the risk of wound dehiscence
and abdominal wall hernias [51]. If the degree of diastasis is too large (>6cm),
staged osteotomies and gradual approximation of the bones may be necessary to
enable pubic rami approximation without an abrupt increase in abdominal and pelvic pressures [37]. An abrupt increase in abdominal and pelvic pressures following
lower abdominal wall closure may result in decreased lung volumes, reduced chest
wall compliance, compromised renal function, glans ischemia, and prolonged ileus
[26]. Pelvic kidneys in particular may experience an increase in renal pelvis pressure, peak systolic velocity, and resistive index compared to orthotopic kidneys at
the time of pubic rami approximation. Those with solitary pelvic kidneys may benet from real-time monitoring during the perioperative period [52].
Genital reconstruction may be pursued during this stage. In males, wide pubic
diastasis and rotational deformities of the pelvic skeletal structures contribute to the
short, pendular penis often accompanied by dorsal curvature. Radical soft tissue
mobilization or the “Kelly repair” has been performed to dissect the corporal bodies
off the pubic rami, which enables medial approximation of the corporal bodies. The
urethral meatus is typically matured in a hypospadiac location [53]. Glans ischemia,
urethrocutaneous stula, vesicocutaneous stula, bladder outlet obstruction, and
bladder and fascial dehiscence are some of the potential complications that can
occur at this stage [26].
It is imperative to avoid urinary obstruction at the bladder outlet level. This can
result in urinary stasis and a higher risk of urinary tract infection. Underlying vesicoureteral reux, which is present in the majority of patients with cloacal exstrophy,
may be addressed at this time. However, performing ureteroneocystostomy may
place the patient at higher risk of iatrogenic obstruction at the level of the ureterovesical junction [30].
15 Cloacal Exstrophy
249
Secondary Procedures
Volitional voiding is typically not an option in those with compromised pelvic
innervation associated with spinal dysraphism. In our experience, urinary continence typically becomes a priority when patients reach school age. Other factors
include skin breakdown in the perineum from chronic urinary leakage. Prior to
any intervention, urodynamics and uoroscopic studies should be performed to
assess bladder compliance and capacity. Cystoscopy and examination under anesthesia may be necessary. Upper tract imaging should be performed. If there is any
concern for nephron loss secondary to congenital dysplasia, obstruction, or infection, a nuclear renal scan can be useful to understand baseline split renal function.
Many will require enterocystoplasty using ileum or hindgut due to a smallcapacity bladder with low compliance. Prior to the operating room, it is useful to
have an understanding of colonic length and degree of dilation through contrast
enema via the colostomy. Ideally, dilated portions of the distal hindgut can be utilized as a bowel segment for enterocystoplasty to avoid a bowel anastomosis.
The bladder outlet can be addressed through bladder neck reconstruction or closure. Extensive preoperative counseling is necessary to ensure patients and caregivers are socially ready for urinary reconstruction. Nonadherence to a strict
catheterization schedule, especially when the bladder neck is closed, can place the
patient at high risk of upper tract damage and bladder perforation. If there is concern
for noncompliance, a narrow bladder neck reconstruction may be preferred than a
complete bladder neck closure, even if this places the patient at higher risk of stress
or overow incontinence.
It is preferable to utilize the appendix or appendiceal appendage for the creation
of an appendicovescistostomy or Mitrofanoff catheterizable channel, since it is a
naturally tubularized structure. If an appendix or appendiceal appendage cannot be
found, distal hindgut or ileum may be utilized as a segment of bowel to create a
Monti catheterizable channel [54].
Fecal continence is also not feasible in majority of cloacal exstrophy patients.
Some patients may be candidates for posterior sagittal anorectoplasty and/or colonic
pull-through. Children with good colonic length, anocutaneous stula, and preserved pelvic innervation may be the best candidates for future pull-through [55]. A
Malone antegrade colonic enema can be considered in those undergoing pullthrough to assist with fecal continence.
Prior to estrogen stimulation, it is challenging to properly assess the anatomy of
Müllerian structures due to underdevelopment. It may be benecial to wait until the
beginning stages of puberty to further delineate the anatomy of Müllerian structures.
A magnetic resonance imaging study of the abdomen and pelvis is the study of choice
to assess the Müllerian structures. Dilation can potentially aid in reconstruction. In the
setting of pain associated with an obstructed Müllerian structure, ovarian suppression
may relieve pain and allow optimal timing of reconstruction. Abdominal pain related
to hematometrocolpos is often mistaken for pyelonephritis, as most of these patients
have chronic bacteriuria. Obstructed Müllerian structures may be temporarily drained
250
through a percutaneous approach in the setting of infection or intolerable pain,
although this is dependent upon a safe “window” for percutaneous access. Müllerian
remnants should be reconstructed or removed based on appearance and shared decision-making with the patient/caregivers. If there is a preexisting channel, vaginoscopy
can be useful to assess for an intact cervix. An intact cervix may decrease future infection risk, so its presence may aid in surgical decision-making [43].
Neovaginal reconstruction may be necessary to bridge the gap. Small and large
bowel segments may be considered for use for reconstruction with the understanding that there is high risk of side effects of malodorous, mucous build up. If there is
a vaginal orice at the perineal surface, augmentation vaginoplasty with buccal
mucosa may be an option [56]. Vaginal stenosis will occur without regular postoperative vaginal dilation. However, vaginal dilation should not be rushed in young
patients, as this may cause signicant anxiety and psychological trauma. Providers
should assess patient/caregiver readiness for vaginal dilation [57]. If not ready, vaginal stenosis can be addressed at an older age.
T. Lee and J. Borer
Outcomes
Urinary Continence
As mentioned above, vast majority of patients will not achieve voluntary urinary
control. Achieving urinary continence through surgical reconstruction requires full
commitment from patients/caregivers. Multiple surgeries are involved, as surgical
reconstruction typically requires revision surgeries. Signicant time, effort, and
nancial resources are utilized to achieve continence even after surgery [58]. Most
importantly, it is imperative to counsel patients and caregivers on the risk of upper
tract damage from what is essentially the creation of a controlled obstruction of the
lower urinary tract.
In a study reporting long-term continence outcomes in 63 cloacal exstrophy
patients, 71.4% had a catheterizable channel, 88.9% of whom were continent
between catheterizations. Incontinent urinary diversion was present in 9.5%, and
4.8% were catheterized per urethra [3]. A recent multi-institutional study of 160
cloacal exstrophy patients reported that, among young children, 42% were incontinent and 32% were on clean intermittent catheterization. Among older children and
adults, 73% were catheterizing, and 88% had a history of enterocystoplasty and
creation of a catheterizable channel. In this case series, 28% of adults had incontinent urinary diversions [60].
Renal
Patients with cloacal exstrophy or OEIS are at particularly high risk for chronic
kidney disease. Anatomic anomalies of the upper tracts are present in 41–66%
[27]. Following urinary reconstruction, the upper tracts are at risk of damage from