A new spectrum of neonatal urethral pathologies in the era of early vesicoamniotic shunting?

Purpose: Intrauterine vesicoamniotic shunting (VAS) was shown to affect survival of male fetuses with megacystis in suspected lower urinary tract obstruction (LUTO). Data on postnatal management are largely lacking. We aim to describe the pathologies diagnosed in children born after vesicoamniotic shunt placement in early pregnancy for megacystis.

Methods: All newborns with previous intrauterine VAS treated in our institution were analyzed retrospectively. We evaluated the clinical spectrum of urethral pathologies. We also compared patients who received a shunt before the 17th gestational week with those who received it later.

Results: Between 2014 and 2023, 26 patients (all male) with a history of VAS for suspected LUTO were treated in our institution postnatally. Five fetuses with dislocated shunts underwent re-implantation in utero. Overall, premature birth before the 38th week of gestation was observed in 14 patients. Seven patients received a Harrison^® shunt whereas 19 received a Somatex^® shunt. Twelve patients required surgical shunt removal under general anesthesia due to shunt migration/embedding. Posterior urethral valves were found in 10/26 patients, 10/26 patients showed a urethral hypoplasia [Fig. 1] and two patients had urethral duplications. In two patients, we identified a prune belly syndrome. One patient had posterior and anterior urethral valves. One patient had a high grade bilateral vesicoureteral reflux without LUTO. The 11 patients shunted early (before 17GW) showed a trend towards a higher proportion of urethral hypoplasia in the early shunt group (54% vs. 26%) without statistical significance.

Conclusion: In our observation, patients treated with VAS had a noticeable high proportion of complex urethral pathologies such as urethral hypoplasia. These data should be taken into consideration for prenatal counselling of parents and planning of postnatal management.