Abstract:

Objective: The Hounsfield unit (HU) is the most common value to assess the stone formation and a predictive factor for the management success. In this study, it was aimed to investigate the prediction of the hardness of the stone using systemic inflammatory response markers.Methods: 192 patients (61 female and 131 male) patients who underwent conventional percutaneous nephrolithotomy (PCNL) between 2015 and 2020 were reviewed retrospectively. Patients with malignancy and history of preoperative urinary tract infection were excluded from this study. Patients’ neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR) and HU of the kidney Stone, which was obtained from NCCT, were recorded to data.Results: The mean age was 47.2 ± 14.11 (11-82) years. The average HU value of the patients’ stones was 1135.47 ± 362.19 (348-2096). The location of the stones was grouped as pelvis (n:64, 33.3%), single calyx (n:14, 7.2%), two calyces (n:93, 48.4%) and staghorn (n:21, 10.9%). In subgroup analysis, when divided by stone location, a negative correlation was found between the HU and N/L ratio in the single calyceal stone group, and a positive correlation was found between the HU and N/L ratio for pelvis and staghorn stones. Among these correlations, only the positive correlation between the HU and N/L ratio in the pelvic stone group was statistically significant (r=0.318, p=0.03). Assuming an arbitrary cut-off value for HU below 1000, there was no significant correlation between NLR and HU (r=0.266, p=0.171). However, HU above 1000, there was a significant positive correlation between NLR and HU (r=0.145, p=0.045).Conclusion: The findings suggest that NLR could be used as a biomarker to choose appropriate management and be helpful to anticipate the hardness of kidney stones by predicting the HU value.

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