Fetoscopic urethral meatotomy in fetuses with lower urinary tract obstruction by congenital megalourethra

BACKGROUND

To describe the perinatal outcomes of fetoscopic urethral meatotomy (FUM) in fetuses with lower urinary tract obstruction (LUTO) by congenital megalourethra.

STUDY DESIGN

Between 2012 and 2020, 226 cases with LUTO were referred to our fetal surgery center in Queretaro, Mexico. We report the perinatal outcome of cases with LUTO by congenital megalourethra that were selected for FUM in an attempt to release the penile urethral obstruction.

RESULTS

Congenital megalourethra was diagnosed in 10 cases (4.4%) but only 3 cases (30%) with obstructive megalourethra and megacystis were selected for fetal surgery. Fetoscopic urethral metatotomy was successfully performed in all three cases at a median gestational age (GA) of 21.4 (18.0-26.7) weeks and with a median surgical time of 27 (12-43) min. A resolution of urethral dilatation and subsequent reduction of the penile length and normalization of both the bladder size and amniotic fluid were observed in all cases. The median GA at delivery was 35.2 (range: 30.6-38.0) weeks. There were no fetal deaths but one neonatal death (33%) secondary to renal failure and preterm delivery.

CONCLUSION

In fetuses with LUTO by congenital obstructive megalourethra, FUM is feasible and is associated with good perinatal outcomes.

Prenatal Diagnosis and Perinatal Outcomes of Congenital Megalourethra: A Multicenter Cohort Study and Systematic Review of the Literature

OBJECTIVES

The purpose of this study was to evaluate the prenatal findings and postnatal outcomes in fetuses with congenital megalourethra.

METHODS

This retrospective study reviewed our experience and the literature between 1989 and 2014. Prenatal findings were evaluated and compared with postnatal findings, including neonatal mortality and abnormal renal function (need for dialysis or renal transplantation).

RESULTS

Fifty fetuses with congenital megalourethra were analyzed, including 6 cases diagnosed in our centers. Most cases (n = 43 [86.0%]) were diagnosed in the second trimester. Only 1 case was diagnosed in the first trimester, whereas 6 cases (12.0%) were diagnosed in the third trimester. Thirty-five fetuses (70.0%) survived. Bilateral hydroureters were associated with perinatal death (P= .024). Among the survivors, 41.9% of the neonates had renal impairment. The following factors were associated with postnatal renal impairment: presence of severe oligohydramnios/anhydramnios (P = .033), bilateral hydronephrosis (P = .008), and earlier gestational age at delivery (P = .022).

CONCLUSIONS

In fetal megalourethra, bilateral hydroureters, bilateral hydronephrosis, and severe oligohydramnios/anhydramnios are associated with neonatal mortality and renal impairment.

Successful Fetoscopic Surgery to Release a Complete Obstruction of the Urethral Meatus in a Case of Congenital Megalourethra

We report the successful use of fetoscopy to treat a case of severe low urinary tract obstruction (LUTO) secondary to a congenital megalourethra. A second trimester male fetus presented at 21 weeks of gestation with massive dilatation of the penile urethra. In addition, bilateral hydronephrosis, an enlarged and hypertrophic bladder, with progressive oligohydramnios were found, suggesting poor prognosis. Extensive counselling was performed and, after the approval from the local ethics committee and informed consent, patients accepted fetal therapy by fetoscopy. The procedure consisted in fetoscopic identification of the tip of the penis and confirmation of the complete absence of the urethral meatus. Thereafter, under combined endoscopic and ultrasound guidance a perforation of the tip of the penis was performed with contact diode laser, until an opening into the urethra was achieved. After the operation, resolution of the cystic penile dilation, with reduction of the penile size, and normalization of the amniotic fluid volume were observed. The pregnancy continued uneventfully and a normal male infant was born at term at the local hospital. The baby was developing normally with normal renal function at 6 months of age. Our report demonstrates that fetoscopic decompression of a distal urethra obstruction can achieve neonatal survival in the rare event of congenital megalourethra.

Lower urinary tract obstruction in the fetus and neonate

This article summarizes the most recent literature regarding congenital lower urinary tract obstruction in the fetus and newborn. Lower urinary tract obstruction is a heterogeneous group of rare diagnoses that have significant potential for in utero mortality and long-term morbidity in survivors. The diagnosis and management of the most common causes are reviewed. In addition, the current state of prenatal intervention for congenital lower urinary tract obstruction is discussed.