BERKELEY, CA (UroToday.com) - While the diagnostic work-up of a patient complaining of renal colic is well established, with respect to follow-up, there remains debate about the best therapeutic protocol.
The general implementation into everyday practice of very sensitive imaging techniques, such as ultrasound and non-contrast computer tomography, has simplified the diagnosis of ureteral stones irrespective of size and radiodensity. However, how we identify those patients to whom we should offer active treatment, either by extracorporeal shockwave lithotripsy or ureteroscopy, versus how we decide which patients should simply be monitored, is still a question that remains to be answered.
There is a general consensus that stone size is the main criterion for treatment decisions and latest guidelines report that calculi <4mm are likely to pass spontaneously and consequently active surveillance may be applied. However, stones >7mm have limited possibilities. In many cases we observe that patients with very small stones are finally operated and patients with large calculi are stone-free after some days or weeks. That means that other factors, apart from size, are also associated with ureteral calculi natural course and this is probably a synergetic action that finally determines stone expulsion or not.
Based on the above observations, we conducted this study aiming to identify parameters that might predict spontaneous passage in a time period of 1 month after the first acute episode of renal colic. The study design had 2 objectives: 1) evaluating patients with stones <15mm (overall analysis) and 2) patients with stones sized 4-10mm (subgroup analysis). As we have reported, stone size and white blood cell (WBC) count during the acute phase were the only parameters found to be statistically significant in the overall analysis in contrast to stone location and side location that were not. Similarly, in the subgroup analysis, WBC count and left-side were the only statistically significant factors.
Our results are adding valuable information to the currently published knowledge because an easily assayed laboratory parameter seems to facilitate treatment decision and its addition to treatment algorithms would enable a more precise prediction of which stones have the potential to pass spontaneously. Undoubtedly relying on WBC count alone would be impractical, and we believe that it would more efficiently used in addition with other proven significant parameters.
What are the pathological pathways through which serum WBCs are increased during a renal colic and, furthermore, what is the pathological and clinical background by which WBC may predict and assist spontaneous passage? We believe that our current results should stimulate studies evaluating the changes and processes taking place at the level of ureteral epithelium and musculature which may then provide answers in the preceding questions. The in-depth definition of the pathophysiology of a renal colic may reveal valuable clinical information that will assist with or even alter the concept of how we evaluate and treat ureteral calculi.
Written by:
Stavros Sfoungaristos,1* Adamantios Kavouras,1 and Petros Perimenis1 as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.
1University Hospital of Patras, Urology Department, Greece
Predictors for spontaneous stone passage in patients with renal colic secondary to ureteral calculi - Abstract
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