Children's Hospital Colorado

Cloacal Exstrophy

Cloacal exstrophy represents a spectrum of rare anomalies that prevent normal development of a baby's lower abdominal wall. With this condition, the intestines and bladder may be exposed outside of the abdominal cavity. Babies with cloacal exstrophy may also have an imperforate anus, which means the opening to the anus is missing or blocked. There are also a number of other defects associated with this condition, which may require extensive intervention and reconstruction before and after birth.

Because a baby's organs can be exposed and there is an imperforate anus, this condition can be very life-threatening during and after pregnancy. However, in the past two decades, reconstruction surgery has provided amazing outcomes for babies with cloacal exstrophy.

At the Colorado Fetal Care Center, we are the forefront of these interventions and strive to provide the best outcomes for babies diagnosed with cloacal exstrophy.

Image of a baby with cloacal exstrophy, a condition in which the intestines and bladder are exposed outside of the abdominal cavity

For patients

Cloacal exstrophy is a rare birth defect that affects approximately 1 in every 200,000 to 400,000 births. 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.

What causes cloacal exstrophy?

Cloacal exstrophy occurs as an isolated event without a recognized cause. There is a higher incidence of cloacal exstrophy in families in which one member is affected as compared with the general population. However, there's no evidence to suggest that anything done by expectant parents leads to the condition.

In some cases, cloacal exstrophy is detected from a routine prenatal ultrasound. In other cases, it isn't diagnosed until birth, when physicians can clearly see the exposed organs. Once diagnosed, additional tests are used to confirm the details of each case and to design a treatment plan. These tests may include:

  • Fetal magnetic resonance imaging (MRI)
  • Computerized tomography (CT) after the baby is born
  • Endoscopy (inserting an instrument to view the inside of an organ)
  • Abdominal ultrasound (using sonography to view internal organs and assess blood flow)

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.

Managing pregnancy after a cloacal exstrophy diagnosis

Because cloacal exstrophy is a high-risk condition, you will need to be monitored throughout your pregnancy. In some cases, pregnancy may be complicated by polyhydramnios (excess amniotic fluid) during the third trimester, which may trigger preterm labor and delivery. Your delivery should also be planned at our state-of-the-art facility. This way, our delivery team can address any complications should they arise and the baby will have immediate access to treatment and the best surgical professionals.

Cloacal exstrophy is treated through surgical repair after birth, usually in stages to address each defect. This requires an in-depth treatment plan to be created for your child's specific needs. 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. Physicians usually repair the bladder, create a colostomy (an opening in the colon with an attached "bag" that allows stool to pass) and repair the abdominal wall defect.

Babies with spinal defects usually have them repaired sometime in the first few days of life. Later surgeries include urinary and genital reconstruction, as well as an operation to create a rectum and close the colostomy opening. There are no fetal interventions (surgical procedures while inside the uterus) for cloacal exstrophy.

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.

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

Surgical techniques to treat this condition have improved dramatically in recent years, which means 90% to 100% of babies survive after surgery. Their quality of life and degree of need for ongoing care vary from case to case. Thanks to the advanced surgical techniques and experienced team at the Colorado Fetal Care Center, your baby will have the highest chances of living a healthy life. We'll be with you from day one to support you and your baby.

Choosing the Colorado Fetal Care Center for cloacal exstrophy treatment and support

The Colorado Fetal Care Center is a world leader in diagnosing and treating the defects associated with cloacal exstrophy. Alberto Pena, MD, a member of our team, is one of the most experienced pediatric surgeons in the world of cloacal exstrophy.

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 and 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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