Children's Hospital Colorado

Cloacal Exstrophy

Cloacal exstrophy represents a spectrum of rare anomalies that are thought to arise from the abnormal development of a structure called the cloacal membrane, thus preventing normal development of the lower abdominal wall. The anatomy in cloacal exstrophy is complex, with an abdominal wall defect consisting of a small omphalocele in the lower abdominal wall (defect in which the intestines and occasionally the liver or other organs are covered only by a sac) at the upper margin of the defect and exposed bowel and bladder at the lower end of the defect. All of these infants have an imperforate anus, which means the opening to the anus is missing or blocked. The anus is the opening to the rectum through which stool (bowel movements) leave the body.  Fortunately, cloacal exstrophy is rare, occurring approximately every 1 in 200,000 to 1 in 400,000 live births. The anatomic features of cloacal exstrophy are seen on ultrasound examination, though an exact diagnosis of cloacal exstrophy might not be made at that time. It is only in recent decades that repair of this complex anomaly has been routinely undertaken. For years most infants were allowed to die because of the multiple and complex anomalies present at birth. However, in the past two decades, survival after reconstruction for cloacal exstrophy has increased to 90% to 100%. There are, however, significant lifelong physical and emotional burden for these patients and their families.  

For patients

Cloacal exstrophy is a rare birth defect. Babies with the condition are born with a single common channel connecting the rectum, vagina, and urinary tract. Part of the large intestine usually develops outside of the abdominal cavity, with the bladder connected to it on either side, in halves. Because the colon is connected to the bladder, urine and stool can mix and there is often no anus. The penis and clitoris are usually split in two, and girls may have more than one vaginal opening. Infants born with cloacal exstrophy can also have spinal abnormalities.   

For parents, the prospect of having a child with such severe birth defects can be both terrifying and overwhelming. But the good news is that while cloacal exstrophy requires multiple surgeries, most patients achieve positive outcomes.

The Colorado Fetal Care Center (CFCC) is a world leader in diagnosing and treating the defects associated with the condition. Alberto Pena MD, a member of our team, is one of the most experienced Pediatric Surgeons in the world in operating on cloacal exstrophy. 

In some cases, cloacal exstrophy is detected from a routine prenatal ultrasound. In others cases, it isn’t diagnosed until birth, when physicians can clearly see the exposed organs. Once diagnosed, additional tests used to confirm the details of each case and design a treatment plan include fetal magnetic resonance imaging (MRI), and after the baby is born computerized tomography (CT), endoscopy (inserting an instrument to view the inside of an organ) and abdominal ultrasound (using sonography to view internal organs and assess blood flow).

Cloacal Exstrophy is treated through surgical repair and a treatment plan will be created for your child's specific needs at the Colorado Fetal Care Center (CFCC), the leader in fetal care.

Treatment Options for Cloacal Exstrophy

Modern medicine has made enormous strides in cloacal exstrophy repair in recent years, and the surgeons at the CFCC are leading experts in diagnosing and treating the condition.

The extent of cloacal exstrophy surgery required for your baby depends on the type and severity of his or her abnormalities. In most cases, surgeons perform multiple operations over the course of several years. This approach, referred to as staged reconstruction, usually begins in the first days of life with the highest-priority procedure. The physicians repair the bladder and create a colostomy and repair the abdominal wall defect. A colostomy means bringing the ends of the large intestine out through the abdomen and attaching them to a collection bag so the infant can eliminate stool.

Babies with spinal defects usually have them repaired sometime in the first few days of life. Later surgeries often include urinary and genital reconstruction, as well as an operation to create a rectum and close the colostomy opening.

Throughout this process, our staff helps prepare families to care for their baby at home. We also connect loved ones with support groups and other resources to help caregivers maintain their emotional and physical health.

Get answers to your questions about your child's cloacal exstrophy diagnosis from top experts at the Colorado Fetal Care Center, the leader in pregnancy care.

What causes cloacal exstrophy?

The cause is unknown, and based on what we do know, it’s not preventable (There’s no evidence to suggest that anything done by expectant parents leads to the condition).

How will this diagnosis affect the management of my pregnancy?

The delivery should be planned in a center capable of reconstructing this complex lesion, or immediate postnatal transport to a tertiary pediatric center should be planned. The pregnancy may be complicated by polyhydramnios (excess amniotic fluid) during the third trimester, which may predispose to preterm labor and delivery. There is an increased incidence of intrauterine fetal death and stillbirth in cloacal exstrophy.

Can this be repaired while my baby is still in the uterus?

There are no fetal interventions (surgical procedures while inside the uterus) for Cloacal Exstrophy.

What is the long-term outcome for babies with cloacal exstrophy?

Surgical techniques to treat this condition have improved dramatically in recent years. While decades ago most babies with cloacal exstrophy died at birth or shortly thereafter, today’s modern procedures enable most to live healthy lives. Their quality of life and degree of need for ongoing care vary from case to case.

Can this happen again in a future pregnancy?

Cloacal exstrophy occurs as an isolated event without a recognized associated chromosomal abnormality (chromosomes can be considered to be the blueprints or instructions for a developing baby). There is a higher incidence of cloacal exstrophy in families in which one member is affected as compared with the general population.

For healthcare professionals

Cloacal exstrophy represents a spectrum of rare congenital anomalies that are thought to arise from maldevelopment of the cloacal membrane, which prevents migration of mesenchymal tissue and impedes normal development of the lower abdominal wall. The cloacal membrane separates the coelomic cavity from the amniotic space during the early embryogenic period. The position and the timing of the disruption of the cloacal membrane will determine the variant of the exstrophy that results. For example, inferior perforation results in epispadias; mid-perforation results in classic exstrophy; and the superior perforation results in superior-vesicle fissure (Jeffs 1987). When cloacal exstrophy is present in its classic form, the constellation of severe abnormalities is among the most difficult for the pediatric surgeon to reconstruct. It consists of exstrophy of the urinary bladder, exstrophy of the small or large intestine, anal atresia, hypoplasia of the colon, omphalocele, and anomalous genitalia, with associated neural-tube defects present in 50% of cases (Fujiyoshi et al. 1987).

The anatomy in cloacal exstrophy is complex, with a ventral abdominal-wall defect consisting of an omphalocele at the superior margin of the defect and exposed bowel and bladder at the inferior extent. The hemibladders are separated in the midline by a zone of intestinal mucosa. Each hemibladder may have a ureteral orifice and the intestinal zone separating the hemibladders may have the orifices of the proximal gut superiorly and the distal gut inferiorly, with one or two appendiceal orifices in between (Warner et al. 1993). The proximal bowel orifice (cecal plate) often prolapses in the characteristic “elephant-trunk” deformity. The distal gut is a blind pouch as these infants all have imperforate anus. Occasionally a colonic duplication may be seen in association with this blind pouch. All genetically male cases have associated genital anomalies, including undescended testicles and a bifid penis with each half attached to widely separated pubic rami (Johnston et al. 1966).

Although cloacal exstrophy was recognized as early as 1909, it was not until 1960 that the first successful reconstruction was reported (Rickham 1960; Warner et al. 1993). It is only in recent decades that repair of this complex anomaly has been routinely undertaken. For years most infants were allowed to die because of the multiplicity and complex nature of the congenital anomalies (Molenaar et al. 1996). However, in the past two decades, survival after reconstruction for cloacal exstrophy has increased to 90 to 100%, albeit with substantial and lifelong physical and emotional burdens for these patients and their families (Manzoni et al. 1987; Soffer et al. 2000).

During early development, the cloacal membrane separates the coelomic cavity from the amniotic cavity. The cloaca is first evident in the midline as an area in which ectoderm and endoderm are in opposition, with no mesoderm in between. By the fourth week of development, the cloacal membrane forms the anterior wall of the urogenital sinus at the base of the allantois. Cephalad and lateral to the cloacal membrane are the primordia of the genital tubercle. These primordia enlarge and fuse in the midline superior to the cloacal membrane to form the genital tubercle. At this same time there is ingrowth of mesoderm toward the midline, increasing the distance between the body stalk and the cloacal membrane, setting up the development of normal infraumbilical body wall. The cloaca becomes divided into the urogenital sinus and the rectum by the urorectal septum, which extends in a medial and caudal direction to the cloacal membrane (Pohlman 1911; Patten et al. 1952).

Patten et al. (1952) suggested the caudal displacement theory for the genesis of cloacal exstrophy. According to this theory, abnormal caudal displacement of the paired primordia of the genital tubercle is responsible for cloacal exstrophy. Epispadias alone would occur if fusion of the primordia in the midline occurred at the level where the urorectal septum joins the cloacal membrane. Exstrophy of both bowel and bladder would occur if even further caudal displacement of the primordia occurred at a level caudal to the anal portion of the cloaca. In contrast, Marshall et al. (1962) suggested the wedge effect of an abnormally large cloacal membrane being responsible for cloacal exstrophy. This abnormally large cloacal membrane acts as a wedge to the developing structure of the abdominal wall. Rupture of this membrane prior to descent of the urorectal septum and fusion of the genital tubercles results in the midline infraumbilical defect, exposure of bladder and bowel mucosa, with bifid and epispadic genitalia. In a chick embryo model, Muecke (1964) has been able to demonstrate that a plastic graft placed in the region of the cloacal membrane produced a wedge defect with persistent cloacal membrane and varying degrees of infraumbilical defects. These theories do not account for involvement of bowel, prolapse of ileum, and foreshortened gut in cloacal exstrophy. Magnus (1969) suggested that a loop of midgut or hindgut prolapses between bladder halves and becomes strangulated. Alternatively, Johnston suggested that the growth of the hindgut is restricted by its involvement in the exstrophy (Johnston 1913).

More recently Bruch et al. observed sonographic progression in a fetus with a dilated cloacal abnormality at 18 weeks of gestation associated with oligohydramnios and hydronephrosis. Repeat ultrasound examination performed at 24 weeks of gestation demonstrated rupture of the cloacal abnormality with resolution of both the hydronephrosis and oligohydramnios. This newborn had the classic features of cloacal exstrophy, challenging previous theories of its embryogenesis (Bruch et al. 1996).

Cloacal exstrophy is associated with anomalies of organ systems other than the central defect in up to 85% of cases (Hurwitz et al. 1987). Anomalies of the urinary tract are common and in several series occurred in 42 to 60% of cases (Hurwitz et al. 1987; Johnston et al. 1966; Spencer 1965; Tank et al. 1970; Ziegler et al. 1986). Vertebral anomalies occur in 48 to 78% of patients (Hurwitz et al. 1987; Spencer 1965; Tank et al. 1970), myelodysplasia, and tethered cord in 29 to 46% of patients (Hurwitz et al. 1987; Ziegler et al. 1986; Levitt 1997).


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