Discussion

The exstrophy–epispadias complex is a spectrum of congenital anomalies that ranges in severity from isolated epispadias, to classic bladder exstrophy, to the most severe form, cloacal exstrophy, often referred to as OEIS complex (Omphalocele, Exstrophy of the cloaca, Imperforate anus, and Spinal defects) as it is associated with omphalocele, imperforate anus, and vertebral defects [1,2]. These conditions are caused by defective midline closure of the lower abdominal wall with abnormal partitioning of the cloacal membrane preventing mesodermal fusion [1,3]. In classic bladder exstrophy, the posterior bladder wall is exposed externally and is frequently associated with genital and pelvic skeletal abnormalities. The estimated prevalence is 1 in 30,000 to 50,000 births [1,4].

Prenatal diagnosis is based on persistent non-visualization of the fetal bladder despite normal kidneys, normal amniotic fluid volume, and adequate time for bladder filling (30-60 minutes). Additional sonographic findings include protrusion of a solid mass between the two umbilical arteries, low umbilical cord insertion, splayed iliac bones or pubic diastasis, and abnormal external genitalia [2-4]. The abdominal wall mass is thought to represent severe bladder hypoplasia and squamous metaplasia of the remaining mucosa [4]. Recognition of these features allows differentiation from omphalocele, gastroschisis, and cloacal exstrophy, though prenatal diagnosis only occurs in approximately 46% of fetuses with bladder exstrophy [3].

Early diagnosis is essential for parental counseling, as postnatal management requires complex staged reconstructive surgery and may be associated with long-term urinary and functional complications [1,3,5]. A staged approach to repair of bladder exstrophy includes reconstruction of the bladder and primary closure of the abdominal wall at birth. At 12–18 months of age, surgery involves repair of the epispadias with corporeal lengthening, dorsal chordee release and urethroplasty in male patients, and vulvoplasty with clitoroplasty in female patients. Operations for urinary continence including bladder neck reconstruction as well as antireflux procedures are performed between 4–8 years of age [1,3]. After surgical correction, urinary continence can be achieved in 90% of cases. Fertility in females is normal, while male patients often require assisted reproductive technologies to father a child [1,2]. Additionally, the patients with bladder exstrophy are at increased risk of developing cancer [5]. These considerations may influence parental decision-making, though pregnancy termination is not routinely advocated [1]. 

References

1. Ebert AK, Reutter H, Ludwig M, et al. The exstrophy-epispadias complex. Orphanet J Rare Dis. 2009 Oct 30:4:23.
2. Mallmann MR, Mack-Detlefsen B, Reutter H, et al. Isolated bladder exstrophy in prenatal diagnosis. Arch Gynecol Obstet. 2019 Aug;300(2):355-363.
3. Hirsch AM, Morrill CC, Haffar A, et al. Optimizing prenatal diagnosis and referral of classic bladder exstrophy: Lessons from a single-institution experience. J Pediatr Urol. 2024 Aug;20(4):619-627.
4. Lee E-H, Shim JY. New sonographic finding for the prenatal diagnosis of bladder exstrophy: a case report. Ultrasound Obstet Gynecol. 2003 May;21(5):498-500.
5. Woodhouse CRJ, North AC, Gearhart JP. Standing the test of time: long-term outcome of reconstruction of the exstrophy bladder. World J Urol. 2006 Aug;24(3):244-