EEC comprises a spectrum of congenital genitourinary abnormalities ranging in severity from epispadias to CBE to CE. These conditions all affect the genitalia, infraumbilical abdomen, and pelvic ring. EEC is a multisystem birth defect involving the genitourinary tract, musculoskeletal system, pelvic floor, bony pelvis, and anus.

CBE is the most common form of EEC. The incidence is estimated to be between 1 in 10,000–50,000 live births [2], while the International Clearinghouse for Birth Defects estimates 3.3 per 100,000 live births [3]. CE is the rarest manifestation of EEC with incidence approximated at 1 per 200,000 live births. EEC is most common in Caucasians, and the male to female ratio ranges from 2.3:1 to 6:1 [3]. It is also more common in infants born to younger mothers and multiparous women. Maternal tobacco exposure is associated with more severe forms (e.g., CE). There is evidence to suggest an increased incidence of this complex of abnormalities in pregnancies utilizing assisted reproductive technologies [4].

Epispadias affects the genitalia and pubic symphysis. The pubic symphysis is diastatic with divergent distal rectus abdominis muscles. In males, the phallus is short and broad with a dorsal chordee. The glans is open along the dorsal surface and shaped like a spade. The dorsal foreskin is absent. The urethral meatus is located along the dorsal penile shaft, between the peno-pubic angle and the proximal glans. In females, the clitoris is bifid with superiorly divergent labia, and the distal dorsal aspect of the urethra is open with a patulous bladder neck (Figs. 19.1 and 19.2). Prolapse of bladder mucosa can sometimes occur.

CBE presents with an open bladder exposed through a triangular-shaped fascial defect on the infraumbilical abdomen (Fig. 19.3). The umbilicus is low set and located on the upper edge of the bladder plate. In both sexes, the distance between the umbilicus and anus is shortened. The anatomy of the levator ani and puborectalis muscles is distorted, leading to varying degrees of fecal incontinence and rectal prolapse. The pubic symphysis is widely diastatic with distally divergent rectus abdominis muscles, which is the result of outward rotation of the innominate bones. There is outward and downward rotation of the anterior pelvic ring ultimately resulting in the classic waddling gait [5–7]. Indirect inguinal hernias are common secondary to wide inguinal rings and short inguinal canals [8, 9].

In males, genital features of epispadias are also present as described above. The urethral and bladder plates are in continuity along the lower abdominal wall and onto the dorsal surface of the penis. The verumontanum and prostatic ducts are present and visible along the prostatic urethral plate. Females also have the same genital features of epispadias, and the open urethral plate is in continuity with the bladder plate. There is anterior displacement of the vagina, which is short.

As in CBE, the bladder is widely open on the infraumbilical abdominal wall but separated into two distinct halves in CE. Cecum is present in between both halves of the bladder. Two appendices may be seen within the cecal plate, and the terminal ileum may prolapse between the hemi-bladders resulting in the so-called “elephant trunk sign”. Most patients with CE have an associated omphalocele.

The pelvic ring has a similar configuration to CBE. 65 % of these patients can have major deformities of the lower extremity, such as clubfoot. Up to 75 % have vertebral anomalies and neural tube defects [10, 11]. In males, the phallus is small and bifid, with a hemi-glans caudal to each hemi-bladder. Females have a bifid clitoris and two hemi-vaginas. The uterus is most commonly bicornuate, but there are varying degrees of Müllerian duplication [12, 13].

A definite cause of EEC has not yet been elucidated. It is hypothesized that early in fetal development (approximately during the fourth gestational week) there is an abnormal overdevelopment of the cloacal membrane, which results in failure of the medial migration of mesenchyme between the ectodermal and endodermal layers of the lower abdominal wall, thus preventing the normal development of the lower abdominal wall [14]. This occurrence makes the cloacal membrane unstable and prone to early rupture (before it migrates into its normal caudal location during gestational weeks 6–8). The stage of development when this premature rupture occurs will determine the severity along the EEC spectrum. When rupture occurs after complete separation of the genitourinary and gastrointestinal tracts via descent of the urorectal septum, CBE results. When rupture occurs prior to this event, externalization of the lower urinary tract and distal gastrointestinal tract occurs, resulting in CE [15].

Transabdominal ultrasonography is the mainstay of prenatal imaging. Although not utilized routinely, there is a role for fetal MRI, which provides more anatomic detail, particularly when anomalies are detected but not fully elucidated on ultrasonography.

The diagnosis of EEC is clinical, yet radiographic imaging modalities can help detect associated anomalies and better define the internal anatomy of the patient.

The differential diagnosis of EEC includes patent urachus, omphalocele, gastroschisis, persistent cloaca and cloacal malformation, as well as the common variants of EEC. These include superior vesical fissure, pseudoexstrophy, duplicate exstrophy, covered exstrophy, and the omphalocele-exstrophy-imperforate anus-spinal defects (OEIS) complex.

Exstrophy variants all have a widely diastatic pubic symphysis with distally divergent rectus abdominis muscles. A low-set umbilicus is common. There may be a small bladder opening or patch of isolated bladder mucosa as seen in superior vesical fissure.

The OEIS complex is the most severe form of EEC and is characterized by an omphalocele, imperforate anus or anal atresia, spinal dysraphism with incomplete development of the lumbosacral vertebrae, and exstrophy of a common cloaca that receives ureters, ileum, and a rudimentary hindgut. There is also failure of fusion of the genital tubercles and pubic rami, epispadias in males and Müllerian duct anomalies in females. There is a wide spectrum of urinary tract malformations, including supernumerary kidney [20].

Patients undergo surgical correction, urinary diversion, or urinary augmentation as treatment of CBE. Planning for surgical correction can be complex and is tailored to the individual patient.

Surgical correction can be performed by the modern staged repair, which involves primary bladder closure with or without pelvic osteotomy within 72 h of birth, epispadias repair between 6 and 12 months of age, and bladder neck reconstruction at 4–5 years of age. Epispadias repair allows for increase in bladder outlet resistance and subsequent increase in bladder capacity. Ureteral reimplantation for VUR is almost universally indicated at the time of bladder neck reconstruction.

Complete primary repair, an alternative approach, encompasses primary bladder closure and genital reconstruction in one operation [21–23]. Because of the advantage of early bladder cycling, some patients have not required additional bladder neck reconstruction to achieve early continence, yet some evidence suggests an increased number of surgical procedures and complications in these patients [24, 25].

Some EEC patients have a bladder plate that is too small for closure or do not develop adequate bladder capacity (>85 mL). These patients may be treated with bladder augmentation with a continent catheterizable stoma (e.g., Mitrofanoff, Monti) or urinary diversion [12, 26].

All EEC patients that have been reconstructed or diverted should be monitored with periodic renal and bladder ultrasonography to assess for evidence of obstruction, upper tract deterioration, or calculus formation.