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13 Bladder Exstrophy-Epispadias Complex

 

 

Postoperative complications include:

Bladder Prolapse

Bladder outlet Obstruction

Vaginal prolapse

Bladder Calculi

Renal Calculi

Wound Dehiscence including urethra and bladder dehiscence

Hypospadias

13.5Cloacal Exstrophy

13.5.1 Introduction

Cloacal exstrophy is an extremely rare birth defect with an estimated prevalence at around 1 in 50,000–200,000 live births (Fig. 13.50).

It is more common in males than females (a male-female sex ratio of 2:1).

Cloacal exstrophy (EC) is a major birth defect representing the severe end of the spectrum of the exstrophy-epispadias complex. It is characterized by the presence of:

Omphalocele

Bladder exstrophy

Imperforate anus

Spinal defects

The size of omphalocele is variable.

It is also called vesico intestinal fissure.

To include the components of cloacal exstrophy, it is also called the OEIS Complex:

O: Omphalocele

E: Exstrophy of the cloaca

I: Imperforate Anus

S: Spinal Defects

Clinically, patients with cloacal exstrophy present at birth and the followings form the spectrum of anomalies that are related to cloacal exstrophy (Figs. 13.51, 13.52, 13.53, 13.54, and 13.55):

Two exstrophied hemi bladders

These are separated by a foreshortened hindgut or cecum

The hindgut is often blind-ending resulting in an imperforate anus. This extrophied ileo-cecal region presents between the two hemi bladders (the “elephant trunk” appearance).

Omphalocele

Malrotation of bowel

The symphysis pubis is widely separated

The pelvis is often asymmetrically shaped

The genitalia (ambiguous genitalia):

The penile or clitoral halves are usually located separately on either side of the bladder plates with the adjacent scrotal or labial part.

Duplication of the vagina and uterus

Vaginal agenesis

OMPHALOCELE

HEMIBLADDER

HEMIBLADDER

Fig. 13.50 Clinical

ILEOCECAL REGION

photograph showing the

 

 

components of the cloacal

 

exstrophy

 

13.5 Cloacal Exstrophy

361

 

 

HEMIBLADDER

OMPHALOCEL

HEMIBLADDER

ILEOCECAL

REGION

 

 

OMPHALOCELE

 

 

 

 

 

 

 

 

 

 

 

HEMIBLADDER

 

 

 

HEMIBLADDER

 

 

 

 

 

 

 

 

 

ILEOCECAL

REGION

OMPHALOCELE

HEMIBLADDER

ILEOCECAL

REGION

Figs. 13.51, 13.52, and 13.53 Clinical photographs showing two patients with cloacal exstrophy. Note the difference in the size of omphalocele and also the extent of the exstrophied ileocecal region

362

13 Bladder Exstrophy-Epispadias Complex

 

 

NO OMPHALOCEL

ANORECTAL AGENESIS

ANORECTAL AGENESIS

Figs. 13.54, 13.55, and 13.56 Clinical photographs showing cloacal exstrophy in three patients. Note the absence of omphalocele in the first one and associated anorectal agenesis in the other two patients

13.5 Cloacal Exstrophy

363

 

 

Bladder Exstrophy-Epispadias Complex represents a spectrum of genitourinary malformations ranging in severity from epispadias and classical bladder exstrophy to cloaca exstrophy. Add to this the exstrophy variants. Among these, cloacal exstrophy is the most severe (Fig. 13.56).

Cloacal exstrophy is characterized by malformations of the gastrointestinal, musculoskeletal, and central nervous systems. Classically, a portion of cecum or hindgut separates the two open hemi bladders.

Three-dimensional CT is valuable to evaluate the bony pelvis and pelvic floor in these patients.

Antenatal imaging demonstrating absence of bladder filling, a low-set umbilicus, widened pubic rami, small genitalia, and a lower abdominal mass that increases throughout the duration of pregnancy may indicate bladder exstrophy or cloacal exstrophy.

The prolapsed ileum in cloacal exstrophy patients may look like an “elephant trunk appearance” on antenatal ultrasound.

Delivery of these patients should be arranged at a specialized medical center with expertise in managing this complex anomaly. Similarly, infants who are diagnosed at birth should be promptly transported to such centers to allow for an experienced evaluation and possibly primary closure.

13.5.2Skeletal Changes in Cloacal Exstrophy

Separation of the pubic bones

Outward rotation of the innominate bones

Eversion of the pubic rami

A 30 % shortage of bone in the pubic ramus

External rotation of the posterior aspect of the pelvis

Retroversion of the acetabulum

External rotation of the anterior pelvis

The sacro-iliac joint angle is 10-degrees larger in the exstrophy pelvis compared to agematched controls and 10-degrees more toward the coronal plane than sagittal.

The bony pelvis is 14.7-degrees inferiorly rotated.

The sacrum was 42.6 % larger by volume measurements and had 23.5 % more surface area.

These deformities of the pelvic bones contribute to the shortened phallus, waddling gait, and outward rotation of the lower limbs in exstrophy patients.

Spina bifida occulta

Lumbarization or sacralization of vertebrae

Uncomplicated scoliosis

Spinal dysraphism including myelomeningocele, lipomeningocele, scimitar sacrum, and hemivertebrae.

13.5.3 Etiology and Pathogenesis

The exact etiology of cloacal exstrophy is not known.

Several theories have been proposed to explain the pathogenesis of cloacal exstrophy but none of them can fully explain the spectrum of anomalies seen in cloacal exstrophy.

The most accepted theory is that cloacal exstrophy results from premature rupture of the cloacal membrane prior to caudal migration of the urorectal septum, and failure of fusion of the genital tubercles.

Embryo logically:

The urorectal septum divides the cloaca into an anterior urogenital sinus and a posterior anorectal canal.

This occurs around the fourth week of intrauterine life and simultaneously, the cloacal membrane is invaded by lateral mesodermal folds.

It is postulated that if this mesodermal invasion does not occur, the infraumbilical cloacal membrane persists leading to poor lower abdominal wall development.

The cloacal membrane eventually ruptures but if this happens prior to the descent of the urorectal septum which happens at 6–8 weeks of gestation, then cloacal extrophy results.