Complications of prenatal vesicoamniotic shunt placement

Fetal lower urinary tract obstruction

The authors present an overview of the prenatal diagnosis, evaluation, contemporary intervention, and antenatal management of lower urinary tract obstruction. They review early experimental models that confirmed the relation between urinary tract obstruction and renal fibrocystic dysplasia and that early in utero relief of the obstruction could prevent irreversible renal injury. Subsequent studies of the electrolyte and protein concentrations in fetal urine from human cases established prognostic threshold values and helped to develop an algorithm to select candidates for antenatal therapy. Although shunting has improved survival, long-term morbidities remain a significant challenge.

Fetal interventions for obstructive uropathy

Obstructive uropathy is a significant source of morbidity and mortality in the neonate and infant, despite advances in postnatal management. Diagnosis is typically made early in the second trimester on the basis of sonographic measurements. In utero therapy holds promise for improved outcomes by preventing progressive urinary tract damage and permitting drainage of urine into the amniotic space to minimize the pulmonary sequelae of oligohydramnios. Multiple studies with animal models have showed the benefits of midgestational intervention, but large prospective, randomized studies have not yet been performed to confirm these findings in humans. Standardization of the diagnostic evaluation allows for refined patient selection, resulting in improved postnatal outcomes after fetal vesicoamniotic shunting. Research into the role of specific growth factors and immunoproteins in renal development and function may further improve patient selection and outcome. This article reviews diagnosis, technique, and outcomes for fetal treatment of obstructive uropathy.