• Failure of the cloacal membrane to be reinforced by ingrowth of mesoderm.
• Abnormal over-development of the cloacal membrane, preventing lower abdominal wall development. Timing of the rupture determines the variant of the exstrophy-epispadias complex that will result.
• Abnormal caudal development of the genital hillocks with midline fusion below rather than above the cloacal membrane.
• Abnormal caudal insertion of the body stalk-failure of interposition of mesenchymal tissue in the midline.

• Pelvic Muscular Defects: The levator muscle group is markedly different in exstrophy versus normal controls. The anterior segment of the levator ani is shorter and the posterior segment longer and they are rotated externally 39^o. The levator hiatus is 2 fold wider than controls and 1.3 fold longer. The puborectal sling is markedly flatter in exstrophy patients. Thus, 70% of the levator group is posterior to the rectum. 35% are anterior compared to a 50/50 ratio in normal controls. Thus, a significant lack of anterior pelvic muscular floor defect exists.
• Pelvic Bony Defects: The posterior pelvis is rotated externally 12^o and the anterior pelvis is rotated 18^o . There is a 30% deficit of pubic bone in addition to the common pubic diastasis. In addition, the sacroiliac joint is rotated 9.9^o with the pelvis rotated 14.7^o in the superoinferior plane . The iliac wing angle is 11.4^o wider than controls. The rotations cause the child to have a waddling gait which reverts to normal as the child ages.
• Umbilicus: Is located at the upper end of the fascial defect and is usually incorporated in the closure of the bladder at the time of surgery.
  Reconstruction of the umbilicus is required.
• Hernias: Inguinal hernias are noted in most patients due to the lack of obliquity of the inguinal canal. They are more common in males and should be repaired at the time of initial bladder closure.
• Anorectal defects: Anal stenosis may be noted in some patients and may require anal dilatation or anoplasty. If anal prolapse occurs, it can usually be easily reduced and is an indication for bladder closure.
• Male Genital defects: The anterior corporal length is 50% shorter in exstrophy versus normal controls while the posterior length is the same. The corporal width in exstrophy is 30% wider than normal controls. Dorsal chordee of the penis is present and may be severe. Usually there should be an adequate length of penis following release of chordee. The testes may appear undescended but this is more due to the flattening of the scrotum than too the lack of cord length. The testes will reach the scrotum without the need for orchiopexy.
• Female Genital defects: The clitoral halves are approximated in the midline giving a satisfactory functional appearance. The vaginal opening may be stenotic and the vagina is short and wide. The cervix is in the anterior wall of the vagina near the introitus. The vaginal opening may require dilatation or surgery for satisfactory sexual intercourse. Uterine prolapse may occur in later life, even before childbearing.
  

• Initial Closure:In the best circumstances, is performed in the first 48 to 72 hours of life. Performance of anterior innominate osteotomy allows the reapproximation of the pubis and abdominal wall without tension. The bladder and the prostatic urethra are closed. Increase in penile length is obtained by separating the corpora bilaterally. The procedure takes 4-6 hours and is performed in conjunction with the pediatric orthopedic surgeons. The patient is placed in traction postop to prevent separation of the pubic bones and an external fixator is utilized. Suprapubic tube and ureteral stents are also left in place. At the end of the procedure, the patient is left with an epispadias. Prophylactic antibiotics are continued post-op and the hospital stay will be three to four weeks. This should only be undertaken by a very experienced exstrophy surgeon.
  
• Epispadias Repair: Usually performed at 6-12 months of age and includes the epispadias repair with urethral lengthening. The epispadias repair is performed using the modified Cantwell-Ransley repair technique. Just prior to epispadias repair, bladder capacity is measured for the first time by a cystogram under anesthesia.
  
• Continence Procedure: Timing depends on the overall performance of the patient with regards to continence and bladder capacity. Ureteral reimplantation is usually performed at this time if it had not been done previously. The child also must be ready to accept a very intense postoperative voiding program.

• Continence:Continence:71-75% of patients are continent following modern reconstruction. With the performance of epispadias repair in early infancy, the increases in the bladder capacity noted have also been dramatic.
  
• Epispadias Repair: The major complication following urethroplasty was fistula formation. The use of osteotomy and performance by an experienced team led to decrease in the rate of fistula formation. The functional and cosmetic appearance of the penis was significantly improved in those patients undergoing staged repair. Satisfactory intercourse was noted in 86% of patients in a recent long-term study from Johns Hopkins.

The Failed Bladder Exstrophy Patient

One of the major interests of the faculty at the Johns Hopkins International Exstrophy Center is the patient with a failed exstrophy reconstruction. This can be as severe as the newborn with a failed closure, the adolescent with continuing urinary incontinence, or the adult female with uterine prolapse. These severe and complicated cases require a dedicated exstrophy team with years of experience with these conditions, as each is unique and challenging. Each year, patients come from around the USA and the world after many failed surgeries looking for help with their exstrophy condition. Many discoveries have been made here at Hopkins by our team of doctors and these led to better and more successful treatment of these failed exstrophy patients.

The young infant with a failed closure presents special challenges for reoperation. A well done osteotomy is mandatory for success (as many failures did not have an original osteotomy). A dedicated pediatric anesthesia pain control team is intimately involved in providing these children state-of-the-art pain control, thus improving patient comfort and also success. While a long-term 4-6 weeks hospitalization sounds formidable, the risk to the infant of an already-failed repair is significant and success with the second repair is mandatory if any chance at all exists for the establishment of voiding continence in the future.

Senior clinical nurses are provided many with over 20 years of experience in dealing with the exstrophy child.

• Bladder Prolapse – post urethra and bladder extrudes through opening
  
• Outlet Obstruction (Posterior urethral) - narrowing of posterior urethra
  
• Bladder Calculi - stone in bladder
  
• Renal Calculi - stone in kidney
  
• Wound Dehiscence - urethra and bladder open again and extrude onto lower abdominal wall.
  

1. John P. Gearhart, Robert D. Jeffs: Exstrophy of the Bladder, Epispadias and other Bladder Anomalies in Campbell's Urology, Sixth Edition. Eds. Walsh PC, Retik AB, Stamey TA, Darracott Vaughan E, Jr., WB Saunders Co. Vol. 2 1772-1821.
   
2. John P. Gearhart: The bladder exstrophy-epispadias complex. In pediatric Urology. Es Gearhart JP, Rink RR, and Mouriquand P. Saunders, Philadelphia. Chapter 32, p 511-546.