[A study of the indication for conservative surgery in adult hydronephrosis based on presurgery post-contrast computed tomography (CT) finding].

BACKGROUND AND OBJECT The cases with adult hydronephrosis are usually performed either conservative surgery or nephrectomy according to the grade of residual renal function. The residual renal function of adult hydronephrosis are usually suspected with analysis of concentration and/or clearance of the renal urine content after percutaneous nephrostomy. However, percutaneous nephrostomy is invasive and risky. On the other hand, post-contrast computed tomography (CT) is non-invasive. We studied whether post-contrast CT is available for the assessment of residual renal function of adult hydronephrosis and also studied the indication for conservative surgery of adult hydronephrosis on post-contrast CT. MATERIALS AND METHODS Conservative surgery or nephrectomy was performed in 14 patients with adult hydronephrosis in the duration from April, 1986 to March, 1995. All of 14 patients (14 kidneys) hydronephrosis were retrospectively studied of the character in the indication for conservative surgery by post-contrast CT before surgery. RESULTS The indication for conservative surgery of adult hydronephrosis on post-contrast CT are (1) well enhanced renal parenchyma exist round the kidney, even if it is very thin, and (2) excretion of contrast medium to renal calyx are showed. CONCLUSION It was concluded that post-contrast CT might be useful for the assessment of residual renal function of adult hydronephrosis.