Nonoperative management of neonatal moderate to severe bilateral hydronephrosis

Purpose: The natural history of prenatally diagnosed bilateral ureteropelvic junction hydronephrosis is unknown. No definite recommendations exist regarding management, and many authors recommend unilateral or bilateral pyeloplasty. We present the results of nonoperative management of bilateral hydronephrosis. Materials and Methods: A total of 16 patients (32 kidneys) with prenatally diagnosed moderate to severe bilateral hydronephrosis were followed nonoperatively. Pyeloplasty was performed only for evidence of deterioration of function and only unilateral surgery was performed when necessary. Results: Of the 32 kidneys 31 had moderate or severe hydronephrosis and 4 (12.5%) required pyeloplasty during a mean followup of 36 months. Hydronephrosis spontaneously resolved or improved in 78% of those observed nonoperatively. Of the 25 kidneys followed nonoperatively for at least 2 years 80% demonstrated improvement. While initial drainage half-time was more than 20 minutes in 55% of kidneys, 78% of unoperated kidneys had a final half-time of less than 20 minutes. Of the 10 kidneys with bilateral severe hydronephrosis 3 (30%) required pyeloplasty. All children had normal glomerular filtration rate for age at the latest followup. Only 1 child has persistent bilateral severe hydronephrosis at age 1 year. Conclusions: Initial nonoperative observation appears to be safe in all cases of moderate to severe bilateral neonatal hydronephrosis. Spontaneous improvement can be expected in most kidneys by 2 years. Only a few children require unilateral pyeloplasty and bilateral operation can be avoided in most cases.