Urolithiasis: The Most Risk for Nephrectomy in Nonrenal Tumor Patients

Background and Purpose: The existence of upper urinary tract calculus may cause complete loss of renal function, which eventually results in nephrectomy. Our purpose was to describe the prevalence and clinical characteristics of upper urinary tract calculus cases among a series of patients undergoing nephrectomy during a 10-year period. Patients and Methods: The data of 1059 patients undergoing nephrectomy between January 2001 and December 2010 in our center were reviewed. The prevalence and clinical characteristics of upper urinary tract calculi-derived nonfunctioning kidney were analyzed. Results: Among 1059 patients, 177 (16.7%) had nonfunctioning kidneys, which were second in number to renal tumor cases (801, 75.6%). Upper urinary tract calculi accounted for the greatest cause (101, 57.1%) in these nonfunctioning kidney cases. These patients were mainly screened by ultrasonography and the diagnosis confirmed by CT, intravenous urography, and nuclear renography. There were 44 (43.6%) patients with a single renal stone in the ureteropelvic junction, 36 (35.6%) with a single ureteral stone, and 21 (20.8%) with multiple unilateral renal and ureteral stones. The average size of the renal stones and ureteral stones were 15.6 +/- 8.8mm (4-50mm) and 13.4 +/- 4.0mm(4-21mm) in diameter, respectively. Prevalence of urolithiasis derived nonfunctioning kidney had not changed significantly over 10 years and even showed a slight increase. Most of the stones were more than 10mmin diameter. A nonfunctioning kidney was more likely to develop in females or patients with a low living standard. Conclusions: Upper urinary tract calculus (>10mm) and loss to follow-up are the greatest risk factors for a nonfunctioning kidney. A nonfunctioning kidney develops more easily in females or patients with a low living standard. A regular urinary system health examination is recommended. Routine follow-up of urolithiasis is also recommended for patients with a stone history to prevent renal dysfunction.