Bladder exstrophy is a rare major birth defect with an incidence of 1 in 10,000-50,000 live births, which requires specialized surgical care. The goals of treatment are to preserve renal function, achieve urinary continence, gain adequate function of external genitalia, and attain acceptable cosmesis. Surgery for exstrophy is complex and challenging, and begins in the newborn period. Associated genitourinary tract anomalies play an important and impactful role in bladder exstrophy patients, directly affecting their treatment plan and surgical outcomes.
A full-term newborn girl with a prenatal diagnosis of classic bladder exstrophy (CBE) was born to a 32-year old G1P0 woman via uncomplicated vaginal delivery. Apgar scores were 9 and 9 at 1 and 5 minutes, respectively. Maternal history was significant for basal cell carcinoma and a carrier state of primary hyperoxaluria type 2. The pregnancy was otherwise uncomplicated except for prenatal ultrasonography findings of fetal bladder exstrophy with left hydronephrosis and hydroureter. Physical examination at birth revealed an abdominal wall defect with bladder found externally. Genitourinary tract examination showed a bifid clitoris, labia separated bilaterally and involved in the bladder defect, and a patent tropisetron (Fig. 1). Pelvic X-ray showed the pubic symphysis to be splayed, with a diastasis distance of 4.4 cm. Ultrasonography after birth revealed a right kidney of normal size, contour, and echogenicity. There was moderate dilation of the left renal pelvis and marked dilation of the left ureter, measuring up to 2.4 cm. Additionally, extraneous tissue in the left lower pole of the kidney was found, reflective of a duplicated collecting system.
On day 1 of life, the patient underwent examination under anesthesia, which revealed a 6 × 5 cm bladder template that was reducible into the abdomen, without significant polyps, and a malleable pelvis. Left retrograde pyelogram and renal ultrasound findings were consistent with a complete duplicated left collecting system with 2 left ureteral orifices very close together below the trigone, and hydroureteronephrosis of the left upper pole. Multisequence, multiplanar magnetic resonance imaging (MRI) was performed the day before exstrophy closure, confirming these renal anomaly findings (Fig. 2).
On day 7 of life, the patient underwent closure in the modern staged repair of exstrophy (MSRE) fashion with bilateral anterior innominate osteotomies. Utilizing intraoperative 3-Dimensional (3-D) MRI BrainLAB (Munich, Germany) imaging, the bladder was incised and dissected down to the urogenital diaphragm and the levator hiatus. Upon further dissection, an ectopic upper pole ureter from the left kidney was found to insert distally on the urethral plate (Fig. 3). A left common sheath ureteral reimplantation (UR) was performed using Politano-Leadbetter technique. The bladder was then closed and the urethral mucosa was closed over a 12-French sound. An umbilicoplasty was also undertaken. The pubic bones were brought together and secured using a nylon stitch. The bifid clitoral hood was joined in the midline and a monsplasty was performed. Per institutional practice, an external fixator and immobilization was applied for 4 weeks to allow healing. Surgical wounds healed nicely and the patient was discharged without any complications. Follow-up renal ultrasound at 1 month was unremarkable, with future imaging every 6 months, and examination under anesthesia with cystoscopy at 1 year to evaluate bladder capacity and anatomical sequelae.
Bladder exstrophy is a spectrum of anomalies involving the urinary genital, musculoskeletal, and gastrointestinal tract. Associated urinary tract anomalies are not uncommon. Stec et al reported that renal anomalies are present in 2.8% of children born with CBE. The most common renal malformation seen in the CBE population is a duplicated collecting system (1.3%), with a proportion of 1:77 among the exstrophy population, a 1.6-fold increase over the incidence in the general population. Other findings include an absent or hypoplastic kidney (0.6%), pelvic kidney (0.4%), multicystic dysplastic kidney (0.2%), and ureteropelvic junction obstruction (0.2%).