[Postoperative outcome of residual pyelocaliceal stones]

The purpose of this paper is to investigate the outcome of postoperative residual stones and their influence to the renal function. We followed up 65 patients (73 kidneys) with residual stones after conventional operation. The follow-up period was on an average 11 years and 9 months. 50 of 73 kidneys were infected before surgery. The most frequently cultured organisms was Proteus mirabilis. Urinary infection persisted in 34 of 50 kidneys after surgery. The residual stones smaller than 5 mm existed in 10 kidneys, of which 7 became sterile. The stones between 5 and 10 mm existed in 18 kidneys, of which 7 (38.9%) became sterile, but in 22 kidneys with stones larger than 10 mm, the infection was not eliminated but in 2 kidneys. Conversely, postoperative infection was never found in 23 kidneys being sterile before operation. Residual stones increased in size in 39 kidneys, did not change in 19 kidneys, diminished in 3 kidneys, fell to the ureter requiring surgery in 7 kidneys and the spontaneous passage of stones was observed in 4 kidneys. In comparing the stone increase group with that of stone stable, the former had a high frequency of stones larger than 5 mm, of postoperative urinary infection and of many stone forming factors. We studied the change of renal function only by IVP in 71 kidneys. Thirty-two kidneys with residual stones and infection showed moderate or severe deterioration of renal function in a large majority of cases. Conversely, in 24 of 34 kidneys without infection, the renal function was stable and only 6 kidneys showed moderate or severe deterioration of renal function.