Exstrophy of the Bladder

This is the most common major congenital defect of lower urinary and genital tract. This is found more frequently in males than in females.

Exstrophy of bladder results when an abnormally large cloacal membrane prevents mesodermal growth and lower abdominal midline fusion. When the cloacal membrance ruptures the anterior abdominal wall, pubis, bladder and urethra fail to develop normally. The paired original tissues of the penis or clitoris fail to fuse in the midline.

In complete extrophy the entire bladder to the external urethral meatus is exposed and may be without ventral covering and this may be accompanied with epispadias, undesceded testes or inguinal hernia.

Incidence

It occurs approximately in 40,000 deliveries.

Pathophysiology

It results from failure of the abdominal wall and its under lying structures to fuse in utero. The anterior surface of the bladder lies open on the lower part of abdomen allowing constant passage of urine to out side. Management includes surgical closure of bladder in 48 hours. Complete correction by school age. Also urinary diversion may be done in some cases.