Table 3: Follow-up of prenatally diagnosed dilatation of the upper urinary tract

 

 

 

 

1.-2.Dayoflife	-------- ►	Ultrasound	-------- ►	No dilatation
	Dilatation	-+-------	3. -5. Day of life
				repeated ultrasound
			I
Bilateral			Unilateral		No dilatation
I	, ultrasound control
3. -5. Day of life VCUG (urethral valves?)		2. -3. Week VCUG (reflux)
	r
			4. -6. Week Scintigraphy IVP (optional)

TREATMENT

UPJ-stenosis

Symptomatic UPJ-stenosis requires surgical correction, whereas asymptomatic unilateral UPJ-stenosis can be subjected to surveillance depending on the grade of obstruction and split renal function. If function does not improve within 3-6 months in patients with a renal function of less than 10% on the affected side, nephrectomy should be considered, especially when symptoms occur (e.g. UTI, hypertension, flank pain). Patients with a function of less than 40% should undergo pyeloplasty. If the partial function is greater than 40%, operative intervention is indicated only if new symptoms occur or function drops more than 10% with time. Sonography should be performed every 4 weeks. Renal function scintigraphy must be repeated within 1 year. Children with a pre-operative partial function below 45% show enhanced growth and an improved overall renal function post-operatively.

Megaureter

According to the official international classification, megaureters are subdivided into primary and secondary, obstructive and/or refluxive and non-refluxive, non-obstructive. Treatment of the refluxive megaureter is dealt with in the section on vesicoureteral reflux (VUR). The diagnostic evaluation is the same as in unilateral hydronephrosis. The degree of obstruction and the split renal function is determined by renal scintigraphy and IVU.

In view of equivalent results of surveillance, surgical intervention based only on the excretory urogram is now rare. With spontaneous remission rates of up to 85% in primary obstructive megaureters, high drainage by means of Sober's or ring-ureterocutaneostomy is no longer justified.

Operative ureterocystoneostomy according to Cohen, Politano-Leadbetter or the Psoas-Hitch-technique can be considered as an operative measure. Indications for surgical treatment of megaureter are recurrent infections under prophylactic antibiotic medication, deterioration of split renal function, reflux persisting for more than 1 year under prophylaxis and significant obstruction.

Ureterocele

Orthotopic ureterocele is a rare finding in children, exclusively observed in females and mostly associated with a single kidney system. It seldom requires surgical intervention, mostly due to complications (e.g. lithiasis). Diagnostic evaluation follows the scheme 'Unilateral hydronephrosis'. VCUG is mandatory prior to a planned operation. An excretory urogram and cystourethroscopy provide additional information on specific questions. Ectopic ureterocele is dealt with in the section 'Obstructive pathology of renal duplication' (see chapter 9).

Retrocaval ureter

A retrocaval ureter is not an anomaly of the ureter but of the vena cava. Diagnostic evaluation follows the scheme 'Unilateral hydronephrosis' (including excretory urogram). In this rare condition, the ureter is divided, its course corrected and end-to-end anastomosis is performed.

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.