Fetal therapy for obstructive uropathy: Specific outcomes diagnosis

Purpose: Attempts to evaluate prenatal vesico-amniotic shunt therapy have been hampered by inconsistencies in patient selection, treatment and termination criteria, and outcomes measurement. Outcomes have generally been measured against those of patients with postnatally detected posterior urethral valves. The purpose of this report was to evaluate the influence of the underlying diagnosis on the clinical outcomes of fetuses undergoing evaluation for prenatal intervention for suspected obstructive uropathy. Furthermore, specific outcomes diagnosis was compared to the published natural history of these disorders to begin to establish a basis for measuring the efficacy of prenatal intervention. Materials and Methods: We retrospectively reviewed the outcomes of 55 consecutive patients undergoing prenatal evaluation using structured outcome measures stratified by specific diagnoses to provide a comparison to the reported natural history for each underlying disorder. Results: All fetuses had early onset of oligohydramnios/anhydramnios representing the worst end of the spectrum. Compared to postnatally diagnosed patients, prenatally diagnosed patients with posterior urethral valves had lower survival (60 versus 93%) but similar postnatal renal failure rates (31 versus 33%). Cases of prenatally detected but untreated posterior urethral valves had a 44% renal failure rate. In fetuses with the prune-belly syndrome survival (86 versus 72%) and renal function rates (17 versus 27% renal failure) compared favorably with the postnatal experience, although 55% of the cases had significant urethral obstruction. All patients with urethral atresia died. Conclusions: The underlying etiology of obstruction appears to have a marked influence on clinical outcome independently of treatment. When evaluated by specific diagnosis, intervention appears to provide outcomes in these high risk fetuses that are comparable to those for disease detected postnatally. Interpretation of series that do not distinguish cases by onset, severity and specific pathological process is problematic. Greater standardization of patient selection, treatment and outcome measurement, including the use of specific diagnoses, is necessary to allow an accurate assessment of the efficacy and proper role of fetal therapy.