In 33 patients with pelviureteric obstruction the renal parenchymal area was measured from excretory urography films and split renal function determined with computerized 99mTc-DTPA-renography. All patients had pelviureteroplasty performed during childhood. For this study, excretory urographs and DTPA-renographs performed in 7 patients preoperatively and in all the 33 patients 10 months to 15 years postoperatively, were analyzed. The parenchymal area of both hydronephrotic and healthy contralateral kidneys showed good correlation with split DTPA clearance. The percentile parenchymal area of the hydronephrotic kidneys also had good correlation to their percentile split DTPA-clearance. The planimetric measurement of kidney parenchymal area and DTPA renography are useful alternative methods when evaluating split renal function, severity of hydronephrosis and the result of pelviureteroplasty.

The renographies of 23 children, treated by means of dismembered pyeloplasty for unilateral pelviureteric obstruction, were analysed. Computerised 99mTc-DTPA renography was performed on each patient both preoperatively and on one or several occasions postoperatively. Of the 13 hydronephrotic kidneys, which had normal glomerular function preoperatively, 12 had also normal postoperative function. In a large proportion of those hydronephrotic kidneys which had reduced glomerular function preoperatively, the function improved after pelviureteroplasty. The improvement was most pronounced in the group of kidneys with severely reduced preoperative glomerular function. The effect of pelviureteroplasty on the washout of DTPA was examined in 13 patients who had diuretic renograms performed both preoperatively and postoperatively. Improved drainage of the hydronephrotic kidney after pyeloplasty was noticed in all these cases.

A series of 161 hydronephrotic kidneys from a 30-year period in 147 children is reported. The left kidney was affected more frequently than the right and the condition was more common in the male than in the female child. In infants, abdominal mass was a common mode of presentation. In older children, loin or abdominal pain, haematuria and urinary tract infection were typical findings. The principles of treatment have changed: during 3 decades there has been a definite shift from nephrectomy to dismembered pyeloplasty, mostly according to Anderson-Hynes technique or its modifications. The results of the dismembered pyeloplasties were good or excellent as contrasted with often unsatisfactory results of the non-dismembered pyeloplasties. There were 1 early and 1 late death in the series; both of these patients were uraemic already preoperatively. The key to good results is the dismembered pyeloplasty with postoperative nephrostomy drainage and applying a stent for the anastomosis, combined with strict control of postoperative pyelonephritis.

The excretory urographies of 26 patients with unilateral pelviureteric obstruction were analysed retrospectively. All patients had had dismembered pyeloplasty performed at the age of 9 months to 15 years 2 months. Planimetric parenchymal area measurements of each kidney were made from urographies performed preoperatively and at different stages of the follow-up period, the latest follow-ups being effected 3 to 14 years postoperatively. The postoperative parenchymal growth of the hydronephrotic kidneys was very good, especially in patients operated on in early childhood. The mean parenchymal growth rate in per cent of the hydronephrotic kidney exceeded the mean parenchymal growth rate in per cent, of its mate during the first postoperative year. During the long-term follow-up there was no further parenchymal "catch-up" growth of the hydronephrotic kidney as compared to the contralateral kidney. Planimetric measurement of kidney parenchymal area is proposed as a useful quantitative method for the preoperative and postoperative evaluation of hydronephrosis in children.