Distribution of ureteral stones and factors affecting their location and expulsion in patients with renal colic.
OBJECTIVE
To evaluate the distribution of ureteral stones and to determine their characteristics and expulsion rate based on their location.


METHODS
We retrospectively reviewed computed tomography (CT) findings of 246 patients who visited our Emergency Department (ED) for renal colic caused by unilateral ureteral stones between January 2013 and April 2014. Histograms were constructed to plot the distribution of stones based on initial CT findings. Data from 144 of the 246 patients who underwent medical expulsive therapy (MET) for 2 weeks were analyzed to evaluate the factors responsible for the stone distribution and expulsion.


RESULTS
The upper ureter and ureterovesical junction (UVJ) were 2 peak locations at which stones initially lodged. Stones lodged at the upper ureter and ureteropelvic junction (group A) had a larger longitudinal diameter (4.21 mm vs. 3.56 mm, p=0.004) compared to those lodged at the lower ureter and UVJ (group B). The expulsion rate was 75.6% and 94.9% in groups A and B, respectively. There was no significant difference in the time interval from initiation of renal colic to arrival at the ED between groups A and B (p=0.422). Stone diameter was a significant predictor of MET failure (odds ratio [OR], 1.795; p=0.005) but the initial stone location was not (OR, 0.299; p=0.082).


CONCLUSIONS
The upper ureter and UVJ are 2 peak sites at which stones lodge. For stone size 10 mm or less, initial stone lodge site is not a significant predictor of MET failure in patients who have no previous history of active stone treatment in the ureter.
Department of Urology, Konyang University College of Medicine, Daejeon, Korea.
Young Joon
YJ
Moon
Department of Urology, Konyang University College of Medicine, Daejeon, Korea.
Hong-Wook
HW
Kim
Department of Urology, Konyang University College of Medicine, Daejeon, Korea.
Jin Bum
JB
Kim
Department of Urology, Konyang University College of Medicine, Daejeon, Korea.
Hyung Joon
HJ
Kim
Department of Urology, Konyang University College of Medicine, Daejeon, Korea.
Young-Seop
YS
Chang
D000328:Adult; D005260:Female; D006801:Humans; D007682:Kidney Pelvis / Q000473:pathology; D008297:Male; D008875:Middle Aged; D056844:Renal Colic / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology*; D012189:Retrospective Studies; D013449:Sulfonamides / Q000627:therapeutic use; D000077409:Tamsulosin; D014057:Tomography, X-Ray Computed; D017211:Treatment Failure; D014513:Ureter / Q000473:pathology; D014514:Ureteral Calculi / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology*; D064804:Urological Agents / Q000627:therapeutic use
D013449:Sulfonamides; D064804:Urological Agents; D000077409:Tamsulosin
Pharmaceutical adjuvants; Renal colic; Ureteral obstruction; Ureterolithiasis