5.3.5 Bilateral hydronephrosis

Bilateral hydronephrosis and megaureter are very rare in girls and require an individual approach, which cannot be dealt with by an algorithm. In boys, the most frequent cause is infravesical obstruction by urethral valves. The obstruction may result in the formation of a trabecular bladder with secondary megaureters and hydronephrosis. After sonography, a VCUG should be carried out without delay. If no pathological findings are discovered, further evaluation follows the 'Unilateral hydronephrosis' scheme. In cases of reflux, diagnostic evaluation follows the 'Reflux' scheme (see chapter 7). In cases of infravesical obstruction with urinary retention, a suprapubic catheter should be inserted immediately and an antegrade VCUG carried out later. Sonography and serum creatine controls should be monitored daily. If sonographic findings improve and serum creatinine falls below 0.6 mg/dL, endoscopic valve resection should be planned between the first and sixth month of life (depending on the baby's size and weight). Endoscopy should take place when the traumatization of the urethra can be minimized. In case of early endoscopic treatment, a stent can be placed in the urethra (6-8 ch) pre-operatively. If there is no improvement of sonographic findings and the serum creatinine does not fall below 0.6 mg/dL, supravesical diversion is necessary and delayed reconstructuion 6 to 9 months later should be planned.

Immediate supravesical diversion is indicated (rarely) in a septic patient with a gross bilateral dolichomegaureter and renal impairment, or in a gross bilateral dolichomegaureter and renal insufficiency that does not respond or continues to deteriorate. The endoscopic cold valve ablation (transurethral or suprapubic) is then performed according to the development of patient conditions and the possibility of spontaneous voiding. A VCUG and a radiological imaging of the diverted upper urinary tract should be carried out pre-operatively.

Table 4: Management of prenatally diagnosed hydronephrosis I

Split renal function < 15% ► Percutaneous nephrostomy

Recovery No recovery

Reconstruction Nephrectomy

Table 5: Management of prenatally diagnosed hydronephrosis II

Split renal function 15 - 40% ► Observation by ultrasound

Repeated scintigraphy 3^rd month of life

Function < 40% Function > 40%

Reconstruction Observation

Table 6: Management of prenatally diagnosed hydronephrosis III

Split renal function: a.p. diameter < 15 mm a.p. diameter > 15 mm

> 40%

Ultrasound every 3 months Ultrasound every month

Scintigraphy every 6 months Scintigraphy every 3 months

Function decreases < 40%

Reconstruction