Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju, Korea.
Department of Urology, Saint Paul Hospital, Hanoi, Vietnam.
Investig Clin Urol. 2024 Sep;65(5):511-517. doi: 10.4111/icu.20240275.
To investigate the variability in urinary stone composition analysis due to sampling and suggest potential solutions.
We collected 1,135 stone fragments from 149 instances that had undergone a stone removal at Hanoi Medical University Hospital from January 2022 to August 2022. Each fragment was ground into fine powder and divided into separate specimens if the amount was abundant. For composition analyzing every specimen, Fourier transform infrared spectroscopy was performed. The composition of a given fragment was the average of its belonging specimens. The variability in composition was assessed on the fragment level (i.e., between fragments of an instance). We defined an instance as "significantly variable" if the maximum difference in any composition across its belonging fragments was equal to or greater than a given threshold.
On average, there were 7.6±3.3 stone fragments per instance and 2.3±0.5 specimens per fragment. We found that the variability could be substantial on the fragment level. Eighty-nine (69.5%) and 70 (54.7%) out of 128 multiple-component instances were significantly variable if the threshold was set at 20% and 30%, respectively. The variability of an instance on the fragment level was correlated with the size of fragment and the number of components.
Our study demonstrated the significant variability in urinary stone composition and showed that it correlated with the size and the impurity of samples. Mapping denotation while sampling and analyzing as well as reporting the composition of individual fragments could be valuable to reduce potential variability.
研究由于采样导致的尿石成分分析的可变性，并提出潜在的解决方案。
我们从 2022 年 1 月至 2022 年 8 月在河内医科大学附属医院进行的 149 例结石清除术中共收集了 1135 个结石碎片。如果数量充足，每个碎片都被研磨成细粉并分成单独的标本。对于每个标本的成分分析，我们都进行了傅里叶变换红外光谱分析。给定碎片的成分是其所属标本的平均值。通过在碎片水平（即一个实例中不同碎片之间）评估成分的可变性。如果给定碎片的任何成分之间的最大差异等于或大于给定阈值，则我们将该实例定义为“明显可变”。
平均每个实例有 7.6±3.3 个结石碎片，每个碎片有 2.3±0.5 个标本。我们发现，在碎片水平上，这种可变性可能很大。如果阈值设定为 20%和 30%，则 128 个多成分实例中有 89 个（69.5%）和 70 个（54.7%）明显可变。实例在碎片水平上的可变性与碎片的大小和成分的数量有关。
我们的研究表明尿石成分分析存在显著的可变性，并表明其与样本的大小和杂质有关。在采样和分析时映射标记以及报告单个碎片的成分可能有助于减少潜在的可变性。
