The Effect of Individual Stone Dimensions on Stone Passage Rates
Objective: The aim of this study is to determine the relationship between each of the three dimensions of a ureteric stone and the passage rateand to identify ureteric stones with an oval/elongated shape and determine whether the stone passage rate was most closely related to any of thethree stone dimensions.Materials and Methods: A retrospective study of all patients who had a computed tomography scan with renal colic protocol at our hospitalbetween January 1, 2016 and June 30, 2017. The maximum axial diameter, axial width, maximum coronal length and location of all stones wererecorded. Patients were followed up for at least six months to ensure that the stones had been expelled or surgically removed.Results: Ninety patients spontaneously passed their ureteric calculus, and 80 patients received surgery in this study. If the patients who receivedsurgery within three days of diagnosis were excluded, the spontaneous stone passage rate was 81.1%. Of the 90 patients with spontaneous stonepassage, 38.9%, 15.6% and 6.7% patients had stones with at least a 1.0, 1.5 and 2.0 mm difference between the maximum axial and coronaldimensions, respectively. Within the subset of calculi that passed within 90 days, these elongated calculi required between 3 and 6 less median daysto pass than the more rounded calculi, although this was not statistically significant.Conclusion: This study showed that in isolation, the individual dimension of a ureteric calculus did not significantly affect the time required to passthe calculus spontaneously. Elongated-shaped calculi were not common in this study.