Surgical or conservative treatment of congenital hydronephrosis. Ten years' experience

Controversy exists concerning the ideal management of hydronephrosis diagnosed in the perinatal period. Different opinions depend on the absence of an accurate tool and of well-defined cut-off values for each test. For these reasons we retrospectively evaluated our management protocol.

Two-hundred and seventy-two patients with single system hydronephrosis were evaluated. Patients with bilateral hydronephrosis or with other renal or ureteral abnormalities were excluded. Diagnosis and grading of hydronephrosis were done by ultrasound. Before 1995, grade II or greater hydronephrosis was also evaluated with diuretic intravenous urography, but in cases studied afterwards, a functional evaluation of the obstruction was reached with well tempered diuretic renogram. Indications for surgery were considered: recurrent urinary tract infections, grade IV hydronephrosis, obstructive drainage pattern and differential renal function less than 40%. Patients managed non-operatively received serial re-evaluation with US-scan, urine test and functional tests if necessary.

Hydronephrosis was on the right side in 98 cases (36%), and on the left side in the other 174 (64%). There were 129 grade I hydronephrosis (47%), 46 grade II (17%), 57 grade III (21%), 40 grade IV (15%). Fifty-seven (21%) cases of hydronephrosis underwent surgery: 49 (86%) showing obstructive pattern at functional tests, 40 (70%) presenting a differential renal function less than 40%, 5 (8%) because recurrent urinary tract infections, 40 (70%) affected by grade IV hydronephrosis. No children received nephrectomy. Average postoperative follow-up was 2.8 years: pelvic dilatation improved or remained unchanged but the obstructive pattern at functional tests always disappeared after surgery. The average follow up in the observational group of 163 patients (60%) was 4.1 years. In 149 (91%) pelvic dilatation improved, but in 14 (9%) it remained unchanged.

The ideal management of congenital hydronephrosis is still debated since the natural history of these disease is not still completely understood and there is no accurate tool to assess these renal units. We believe that grade IV hydronephrosis always need surgery as well as those ones with recurrent urinary tract infections, longer drainage time or a differential renal function less than 40%. On the other hand grade I hydronephrosis never need surgery. Mild grade hydronephrosis can be safely managed non-operatively with a meticulous follow-up and undergoing surgery only when signs of deterioration occur.