The usefulness of the Hounsfield unit and stone heterogeneity variation in predicting the shockwave lithotripsy outcome.

PURPOSE This study aimed to evaluate the use of stone density variation coefficient (SDVC) as an indicator of stone heterogeneity and previously reported parameters for predicting extracorporeal shock wave lithotripsy (ESWL) outcome in urinary calculi. Moreover, a new formula that could be used to predict ESWL success was suggested. METHODS A total of 850 patients, who underwent the first session of ESWL for urinary stones between 2015 and 2020, were examined, and 220 eligible patients were included in the study. Stone density variation coefficient and other parameters associated with stone attenuation values and stone size parameters were studied as potential predictors based on noncontrast com- puted tomography (NCCT). Extracorporeal shock wave lithotripsy success was considered after 3 months by radiography or NCCT. Logistic regression analysis was performed to determine the factors contributing to treatment success. RESULTS For the 220 patients, ESWL success rate was 39.5%. The receiver operating characteristic analysis showed that SDVC (AUC=0.82; 95% confidence interval [CI]: 0.76-0.87; P < .001), mean stone density (AUC=0.81; 95% CI:0.75-0.87; P < .001), maximum stone density (AUC=0.70; 95% CI: 0.63-0.78; P < .001), stone volume (AUC=0.70; 95% CI: 0.62-0.77; P < .001), and major diam- eter (AUC=0.67; 95% CI: 0.59-0.74; P < .001) had significant prediction accuracy from high to low. Additionally, SDVC was found to be successful in predicting ESWL success, especially for patients with high mean stone density (OR = 10; 95% CI: 3.55-28.57; P < .001). The logistic regres- sion model, in which the "stone disintegration probability" (SDP) formula was found, correctly predicted ESWL success with a single session by 79.1%. CONCLUSION In conclusion, size and attenuation values were predictors of treatment success, and the best predictor was SDVC. Evaluation of SDP formula prior to ESWL could predict treatment outcomes and facilitate the decisions regarding treatment strategies.

Percutaneous nephrolithotomy in pediatric patients: is computerized tomography a must?

The aim of this study was to retrospectively evaluate the results of pediatric percutaneous nephrolithotomy (PNL) cases, and discuss the results and necessity of non-contrast computerized tomography (CT) in these cases. In all, 48 pediatric patients who underwent PNL were retrospectively evaluated. Before PNL, either intravenous urography or CT was performed. In all patients, we evaluated the PNL time, scopy time with stone burden, and complications. During the PNL procedure, we switched to open surgery in two cases: in one because of renal pelvis perforation and in the other because of transcolonic access. In one patient who was scheduled to undergo PNL, we performed open surgery, primarily because we detected a retrorenal colon with CT. The stone burden in 45 patients who underwent PNL was 445 ± 225 mm(2), the PNL time was 51 ± 23 min, and the scopy time was 6.1 ± 2.7 min. We removed nephrostomy tubes 1-4 days after the procedure. In two patients, 24 h after removal of nephrostomy tubes, we inserted double J stents because of prolonged urine extravasation from the tract. In all, 34 of the 45 patients were stone-free, 5 patients had clinically insignificant stone fragments, and 6 patients had residual stones. PNL is a safe and effective method in the treatment of pediatric patients with kidney stones. Clinical experience is the most important factor in obtaining stone-free results. CT should be performed in all pediatric patients in order to prevent colon perforation.

Body mass index, body fat percentage, and the effect of body fat mass on SWL success.

OBJECTIVES: In the present study, we investigated the effects of the Body Mass Index (BMI), the Body Fat Percentage (BFP), and the Body Fat Mass (BFM) on success of SWL, prospectively. PATIENTS AND METHODS: The BMI, BFP, BFM values of patients, who were treated by SWL due to upper urinary system stone disease (pelvis renalis, upper ureter, kidney lower and upper calices) between January and December 2005 in our hospital's urolithiasis center, were measured. Patients with stones smaller than 5 mm or larger than 20 mm and patients who had a stone localized somewhere other than in the upper urinary system, were not included in the study. Patients evaluated to be clinically successful according to the SWL were put in group 1, and the other patients who were not successful were included in group 2. RESULTS: About 158 (97 male, 61 female) patients aged between 16 and 92 (mean 36.69 (+/-13.22) years), put on SWL therapy due to presence of upper urinary system stone disease, were included in the study. While the mean BMI was 23.97 +/- 0.4 in group 1 and 25.98 +/- 0.5 (P = 0.02) in group 2, BFP was 23.85 +/- 0.8 in group 1 and 29.19 +/- 1.1 (P = 0.001) in group 2, and BFM was determined to be 16.74 +/- 0.7 and 21.19 +/- 1.01 (P = 0.001) in group 2. Regarding all the parameters (BMI, BFP, BFM), the statistical analyses carried out between the groups showed significant differences. CONCLUSION: BFP and BFM parameters are also important factors along with the BMI in providing a successful SWL treatment. All the parameters should be considered regarding the success of the treatment and the patients should be informed.