Fetoscopic laser surgery to decompress distal urethral obstruction caused by prolapsed ureterocele.

We report on the successful use of fetoscopic surgery to treat a case of prolapsed ureterocele in a female fetus. At 21 weeks' gestation, a double renal system with an intravesical ureterocele obstructing the bladder outlet was diagnosed, causing severe megacystis, bilateral hydronephrosis and progressive oligohydramnios. Ultrasound evaluation following referral to our center confirmed severe bilateral hydronephrosis with pelvic and calyceal dilatation, but amniotic fluid volume was normal and the ureterocele was not visualized in the bladder. Instead, a cystic mass within the external genitalia was observed, suggestive of a prolapsed ureterocele, causing intermittently severe obstruction of the urethra. The parents were counseled about the uncertain prognosis and fetal surgery to decompress the urinary system was proposed. The procedure involved firing a contact diode laser until perforation of the ureterocele was achieved. Following laser surgery, resolution of megacystis, reduction of hydronephrosis and normalization of amniotic fluid volume were observed. Our report demonstrates that fetoscopic decompression of a distal urethral obstruction is feasible in the rare event of congenital prolapsed ureterocele.