(UroToday.com) Dr. Margaret Knoedler and team conducted an intriguing study on the determined stone composition of calcium phosphate stones among fragmented stones and whole stones. Stone analysis is an important factor in treating stones as it helps determine the medical and surgical management of stone disease. The two common ways to collect stones are through urinary passage and surgical extraction. Once stones are collected, they are sent to lab for analysis. This study explored the difference between the physical state of the stones sent to laboratories; specifically, the team sought to determine if fragmented stones and whole stones provide the same stone analysis.
The study investigated 5,069 stone analyses from an IRB approved surgical database from a single institution between 1997 to 2021. The stones assessed in this study were primarily composed of 60% calcium phosphate. Univariate analysis with chi-square and independent T-test was used to analyze the findings from the laboratory reports.
Of the 5,069 stones specimens, there were 2,228 whole stones and 2,841 fragmented stones. There were 4,350 stones that contained any amount of calcium phosphate. In the whole stones, 17.7% (1,940) contained trace amounts of calcium phosphate and in fragmented stones there was 26% (2,410).
A total of 572 stones were primarily calcium phosphate stones. Of these stones, 190 were whole meaning only 8.5% of the 2,228 whole stones were primarily composed of calcium phosphate. There were 382 fragmented stones that were primarily composed of calcium phosphate, therefore, making up 13.4% of the 2,841 available fragmented stones.
Dr. Knoedler’s team concluded that for both the primary calcium phosphate group and any calcium phosphate group the percentages were higher and in favor of fragmented stones; this finding was unexpected as they hypothesized that both groups would yield similar results. Based on their findings, Dr. Knoedler suggests that repeat stone analyses for individual patients may help further characterize stone disease. During the discussion of the presentation, an audience member asked where the stones came from to which Dr. Knoedler explained that the stones were from a surgical database. The stones were from PCNL’s, ureteroscopies, and patients who passed stones after surgical intervention, as well as being from both primary and secondary procedures.
This study shows how crucial it is for accurate stone analyses. Fragmented stones provide a clearer understanding of one’s stone composition. The misrepresentation of a patient’s stone composition may result in suboptimal recommendations in lifestyle changes and other therapies. Therefore, as mentioned by Dr. Knoedler, repeat stone analyses and proper metabolic evaluations can greatly impact the decision making in regard to a patient’s care.
Presented by: Margaret A. Knoedler, MD, University of Wisconsin School of Medicine and Public Health
Written by: Seyed Amiryaghoub M. Lavasani, B.A., University of California Irvine, @amirlavasani_ on Twitter during the 39th World Congress of Endo urology and Uro-Technology (WCET), Oct 1 - 4, 2022, San Diego, California.