Purpose: We investigated the characteristics and diagnosis of primary asymptomatic ureteral calculi.
Materials and methods: During a period of 12 years asymptomatic ureteral stones were prospectively investigated at the Urological Stone Center. We studied mode of diagnosis, stone size, localization, composition, hydronephrosis grade and patient characteristics.
Results: Between 1995 and 2006 a total of 40 patients with asymptomatic ureteral stones were identified among 3,711 patients with ureteral stones (1.1%). Mean age of the 33 male and 7 female asymptomatic patients was 58.3 years (range 28.1 to 87.1). Localization of stones was 19 proximal, 3 mid and 18 in the distal ureter. Mean stone size was 10.0 mm (+/-6). Mode of diagnosis of asymptomatic calculi was randomly diagnosed hydronephrosis in 10 patients (25%), microscopic hematuria in 8 (20%), randomly diagnosed stone on other than urological x-ray examination in 13 (32.5%) and stone diagnosed during followup after previous nephrolithiasis in 9 patients (22.5%). Primary therapy was extracorporeal shock wave lithotripsy in 35 patients (87.5%), ureterorenoscopic lithotripsy in 4 (10%), spontaneous stone passage before scheduled treatment in 1 and open ureteroneocystostomy in 1 patient.
Conclusions: De novo asymptomatic ureteral calculi do exist. Characteristics of this small group of patients with ureterolithiasis have not been described thus far. Diagnosis is usually made during routine health care examinations, during the evaluation of nonurological diseases and during followup of patients who previously had nephrolithiasis. A large proportion of patients exhibit some degree of hydronephrosis as a sign of silent obstruction.