Grahame H.H. Smith, MBBS
BASICS
DESCRIPTION
• Classic bladder exstrophy is a major genitourinary anomaly characterized by the bladder laying open on the abdominal wall with an associated lower midline abdominal wall hernia. The defect extends from the umbilicus to the distal end of the phallus, resulting in coexistent epispadias in males and a bifid clitoris in females.
• Classic exstrophy is considered midway in severity between cloacal exstrophy and epispadias, as part of exstrophy–epispadias complex.
EPIDEMIOLOGY
Incidence
• 1 in 10,000–50,000
• Male > Female (2:1)
Prevalence
N/A
RISK FACTORS
Genetics
• Multifactorial etiology without definite genetic link (1)
– May be associated with p63 gene dysregulation
– Chromosomal regions 4q31.21–22, 19q13.31–41, and 22q11.21 may harbor genes associated with exstrophy
• Risk in sibling is 1 in 100; risk in offspring is 1 in 70
PATHOPHYSIOLOGY
• Incompletely understood, 2 predominant theories
• 1st theory postulates that an incomplete ingrowth of mesoderm is unable to reinforce cloacal membrane, which results in premature rupture and subsequent failure to develop ectoderm and mesoderm. The timing of the rupture determines cloacal (earlier) vs. classic exstrophy vs. epispadias (later)
• 2nd theory describes an overgrowth of cloacal membrane preventing medial migration of mesenchymal tissue. Bladder smooth muscle cells in exstrophy patients show lower intracellular calcium concentrations and enhanced migration
ASSOCIATED CONDITIONS
• Usually healthy without any other major organ system defects
• Subsequent inguinal hernia common
• Rarely may be associated with duplication of bladder or urethra, colorectal abnormalities (2%), cleft lip and palate, subsequent testis tumors
• In contrast, cloacal exstrophy has much more extensive anomalies
GENERAL PREVENTION
N/A
DIAGNOSIS
HISTORY
Any family history of exstrophy
PHYSICAL EXAM
• Bladder exposed on abdominal wall
• Bladder plate size
• Lateral ureteric orifices
• Males have an open bladder neck and prostate, the short and broad phallus is open dorsally with dorsal chordee
• Females have an open bladder neck and urethra, bifid clitoris lateral to urethra and anteriorly situated vagina
• Low-set umbilicus with foreshortened distance to pubis
• Pubic diastasis with external rotation of pelvis
DIAGNOSTIC TESTS & INTERPRETATION
• Antenatal
– May be diagnosed on antenatal ultrasound study due to absence of the bladder (1st trimester) or reduced umbilical to pubic length (2nd trimester)
Lab
• Full blood count, electrolytes, creatinine
• Blood type and cross-match in preparation for surgery
Imaging
• Renal ultrasound
• Pelvic x-ray to document pubic diastasis
Diagnostic Procedures/Surgery
N/A
Pathologic Findings
• Exstrophic bladders may have more type III collagen and fewer myelinated nerve fibers
• If left untreated and exposed, the urothelium undergoes squamous metaplasia as a response to acute and chronic inflammation
DIFFERENTIAL DIAGNOSIS
• Cloacal exstrophy
• Omphalocele
• Gastroschisis
• Epispadias
TREATMENT
GENERAL MEASURES
• Antenatal
– Consider MRI assessment and karyotyping. Options for termination may be discussed
• Immediate postnatal care:
– 2-0 silk suture on umbilical cord as close to abdominal wall as possible
– Cover bladder with a nonadherent dressing (eg, Saran Wrap) to prevent excoriation
– Irrigate with normal saline and apply a new dressing with each diaper change
MEDICATION
First Line
No medical treatment is available to close the bladder wall
Second Line
N/A
SURGERY/OTHER PROCEDURES
• Ideally the extrophy is closed on next elective list with two senior staff in attendance:
– Requires an adequate bladder plate but the minimum size is not defined
– If unable to easily approximate pubis, then may need pelvic osteotomy
– Pelvic osteotomy may reduce the incidence of dehiscence and subsequent prolapse in females
• Avoid latex exposure to prevent latex allergy
• 3 contemporary closures (2)
• Classic repair involves 3 stages:
– Immediate bladder closure
– Epispadias repair at 6 mo
– Bladder neck repair at 5 yr:
Requires >100-cc bladder capacity and motivation for continence
• Complete primary repair of bladder exstrophy (CPRE):
– Epispadias repaired along with bladder as neonate with penile disassembly (if male)
• Kelly repair:
– Soft tissue mobilization away from pelvic sidewall with midline closure without the need for pelvic osteotomy
• Associated surgery
– Prophylactic inguinal hernia repair in males is advised
– Ureteric reimplantation may be required subsequently
ADDITIONAL TREATMENT
Radiation Therapy
N/A
Additional Therapies
• Delayed closure in the case of a late presentation
• All need osteotomy with option of external fixation
• Inadequate bladder plate:
– Delay closure with osteotomies, once adequate
– If remains inadequate consider augmentation at time of closure
• Postoperative:
– Ensure maximal urinary drainage with ureteric stents, suprapubic tube, and urethral catheter
– With our without pelvic immobilization (traction, Buck, Bryant; Mermaid dressing; spica cast)
Optimal duration of immobilization not established
– Remove stents one at a time; suprapubic only removed after ensuring appropriate bladder emptying
Complementary & Alternative Therapies
N/A
ONGOING CARE
• Subsequent operative treatment options:
– Bladder neck plasty (failure rate 50%)
– Bladder neck closure (failure rate 2%) with augmentation and Mitrofanoff conduit
– Ureterosigmoidostomy (plus or minus Mainz II pouch)
– Umbilicoplasty
– Radial forearm flap phalloplasty (males)
– Vaginoplasty, clitoroplasty (females)
PROGNOSIS
• Life expectancy normal
• Urinary continence in 50–90%; definition of continence disputed; most common definition of continence is dry with voiding or catheterization every 3 hr (3)
• May require multiple surgeries
• Quality-of-life scores are less than the normal. Functional results seem to be the most likely predictive factor of health-related QOL score
COMPLICATIONS
• Failure of primary closure; 10%
• Failure to store (urinary incontinence secondary to incompetent outlet plus or minus poor bladder compliance)
• Failure to empty (after closure or after bladder neck procedure)
• Upper tract damage and renal failure due to high bladder pressures and or high outlet resistance
• Developmental psychopathology
• Male: Infertility, retrograde ejaculation, urethrocutaneous fistula, loss of phallus (complete penile disassembly, Kelly repair), inadequate phallus, testis tumors
• Female:
– Vaginal stenosis, requiring vaginoplasty
– Degree of diastasis association with risk of uterine prolapse
– Enterocystoplasty may lead to false-positive pregnancy test
– Normal fertility possible, Cesarean delivery suggested
• Increased risk of adenocarcinoma of bladder
• Increased risk of colonic adenocarcinoma after ureterosigmoidostomy
FOLLOW-UP
Patient Monitoring
• After discharge:
– Antibiotic prophylaxis to prevent urinary tract infections
– Regular ultrasound to assess for hydronephrosis, residual volume, and bladder volume
– Yearly colonoscopy starting 10 yr after ureterosigmoidostomy
Patient Resources
The Association of Bladder Exstrophy. Community. http://bladderexstrophy.com/
REFERENCES
1. Mahfuz I, Darling T, Wilkins S, et al. New insights into the pathogenesis of bladder exstrophy-epispadias complex. J Pediatr Urol. 2013;9(6 Pt B):996–1005.
2. Mahajan JK, Rao KL. Exstrophy epispadias complex - Issues beyond the initial repair. Indian J Urol. 2012;28:382–387.
3. Lloyd JC, Spano SM, Ross SS, et al. How dry is dry? A review of definitions of continence in the contemporary exstrophy/epispadias literature. J Urol. 2012;188(5):1900–1904.
ADDITIONAL READING
• Palmer B, Frimberger D, Kropp B, et al. http://www.pediatricurologybook.com/bladder_exstrophy.html
• Reiner WG. A brief primer for pediatric urologists and surgeons on developmental psychopathology in the exstrophy-epispadias complex. Semin Pediatr Surg. 2011;20(2):130–134.
See Also (Topic, Algorithm, Media)
• Epispadias
• Exstrophy, Cloacal
• Exstrophy–Epispadias Complex
• Exstrophy, Bladder (Classic Exstrophy) Images 
CODES
ICD9
753.5 Exstrophy of urinary bladder
ICD10
• Q64.11 Supravesical fissure of urinary bladder
• Q64.19 Other exstrophy of urinary bladder
CLINICAL/SURGICAL PEARLS
• Achieving normal urinary continence with normal voiding after repair is uncommon. It is almost always possible to achieve continence if the patient is willing to undertake clean intermittent catheterization.
• Males will tend to be unhappy about the length of their penis. However, what they lack in length they gain in width.
• For the inexperienced clinician it is sometimes difficult to identify the gender of a newborn baby with bladder exstrophy. Boys almost always have bilateral palpable gonads.