Fetal surgery for posterior urethral valves: Long-term postnatal outcomes

Objective. Fetal intervention for obstructive uropathy was first performed at the University of California, San Francisco in 1981. Indications for tre atment were bilateral hydronephrosis with oligohydramnios. Preintervention criteria included fetal urinary electrolytes with beta -microglobulin level s, karyotyping, and detailed sonography specifically looking for renal cort ical cysts. We reviewed the outcomes of children who underwent fetal interv ention with specific long-term follow-up in patients who were found postnat ally to have posterior urethral valves. Methods. A retrospective review of the University of California, San Franci sco fetal surgery database was performed for patients with a prenatal diagn osis of obstructive uropathy. Medical records from 1981 to 1999 were review ed. Long-term follow-up was documented if the cause of the urinary tract ob struction was posterior urethral valves. We collected data points, focusing on time and type of intervention, fetal urinary electrolytes, appearance o f fetal kidneys, present renal function, length of follow-up, and present s tatus of the urinary tract. Results. Forty patients were evaluated for fetal intervention; 36 fetuses u nderwent surgery during this time period. Postnatal confirmation of posteri or urethral valves was demonstrated in 14 patients. All patients had favora ble fetal urinary electrolytes. Mean gestational age at intervention was 22 .5 weeks. The procedures performed included creation of cutaneous ureterost omies in 1, fetal bladder marsupialization in 2, in utero ablation of valve s in 2, and placement of vesicoamniotic catheter in 9. Six deaths occurred before term delivery with premature labor and the newborns succumbing to re spiratory failure. One pregnancy was terminated electively because of shunt failure and declining appearance of fetal lungs and kidney. The remaining 8 living patients had a mean follow-up of 11.6 years. Chronic renal disease with abnormal serum creatinine was present in 5 patients. Two patients hav e undergone renal transplantation, and 1 is awaiting organ donation. Five o f the 8 living patients have had urinary diversion with vesicostomy, cutane ous ureterostomy, or augmentation cystoplasty with later reconstruction. Conclusions. Fetal intervention for posterior urethral valves carries a con siderable risk to the fetus with fetal mortality rate of 43%. The long-term outcomes indicate that intervention may not change the prognosis of renal function or be a predictor for possible urinary diversion. Despite all of t hese patients' having favorable urinary electrolytes, this did not seem to have any implication postnatally. When counseling families about fetal inte rvention, efforts should be focused on that intervention may assist in deli vering the fetus to term and that the sequelae of posterior urethral valves may not be preventable. Fetal surgery for obstructive uropathy should be p erformed only for the carefully selected patient who has severe oligohydram nios and "normal"-appearing kidneys.