Prognostic Factors for the Effectiveness of Extracorporeal Shock Wave Lithotripsy in Patients with Ureterolithiasis

The purpose of the work was to study prognostic factors for the effectiveness of extracorporeal shock wave lithotripsy in patients with ureterolithiasis. Materials and methods. The study included 53 patients with ureteral stones up to 2 cm in size. All patients underwent extracorporeal shock wave lithotripsy under ultrasound control, with a pulse rate of 90 per minute and a maximum number of pulses of 2000 per session. The outcome of treatment was evaluated by ultrasound on day 5 after the extracorporeal shock wave lithotripsy session. If there were stone fragments larger than 5 mm, a second extracorporeal shock wave lithotripsy session was performed. Treatment was considered effective in the absence of stone fragments in the urinary tract 4 weeks after extracorporeal shock wave lithotripsy. Results and discussion. The data were analyzed to identify clinical and radiological factors associated with treatment failure. As a result of the treatment, 46 (86.4%) patients were found to have no stones in the urinary tract (the condition is “stone free”), 9 (13.6%) had stone fragments larger than 5 mm 4 weeks after extracorporeal shock wave lithotripsy, and therefore contact ureterolithotripsy was performed. As complications, 7 (13.2%) patients had an exacerbation of chronic pyelonephritis, which required percutaneous nephrostomy. As the results showed, age, gender, body mass index, and Hausfield units did not differ significantly in terms of extracorporeal shock wave lithotripsy results. Factors that significantly affected the prognosis of extracorporeal shock wave lithotripsy success were the size of the stone and skin-stone distance. Body mass index did not significantly affect the outcome of lithotripsy in this study. The stone density index according to computed tomography data is considered by many authors to be a predictor of the effectiveness of fragmentation, but in our study this indicator was not a significant predictor of the effectiveness of extracorporeal shock wave lithotripsy, which allows us to think that there are other factors, namely the features of the internal structure of the stone, which determine its compliance with the shock wave. Conclusion. The size of the stone and the skin-stone distance are prognostic factors that affect the effectiveness of extracorporeal shock wave lithotripsy in patients with ureterolithiasis. Body mass index and stone density in Hausfield units did not significantly affect extracorporeal shock wave lithotripsy outcome in this study

Outcomes of fluoroscopy-free retrograde intrarenal surgery and predictive factors of stone-free

Objective: To evaluate the outcomes of flouroscopy-free retrograde intrarenal surgery (ffRIRS) and to investigate the factors that may affect stone-free rate. Materials and methods: The charts of patients who underwent ffRIRS between January 2017 and August 2019 were reviewed retrospectively. Patients with missing preoperative imaging and patients with kidney anomalies were excluded from the study. Age, gender, stone size, stone localization, stone density, laterality, operation time, stone-free rate, complications and auxiliary procedures were recorded and analyzed. Results: Study group involved 44 (43.1%) female and 58 (56.8%) male patients. Stone-free rate in a single-session ffRIRS were found to be correlated with stone localization (p = 0.003), stone volume (p = 0.004), and stone density (p = 0.009) but not with age (p = 0.950). Patients with multiple calyceal stones and a stone burden over 520 mm3 were found to be less stone-free. The complication rate in female gender (n = 7) was significantly higher compared to male (n = 1) (p = 0.011). No major complications such as ureteral injury or avulsion were observed. Overall, 13 patients (12.7%) needed auxiliary procedures. The operation time seemed to be affected by stone size and gender (p = 0.005; p = 0.044, respectively). Conclusions: Stone-free rate in ffRIRS were found to be affected by stone density, size, and localization. Patients with multiple caliceal stones and high stone burden (< 520 mm3) have been found to have low stone-free rate, so one can speculate that having fluoroscopy assistance in RIRS might help us to improve surgical success.

External validation of the T.O.HO. score as predictor of success after retrograde intrarenal surgery

Background To assess the effectiveness of T.O.HO. (Tallness, Occupied lesion, Houndsfield unit evaluation) score in predicting the retrograde intrarenal surgery (RIRS) success and to validate this scoring system. Methods The age, sex, previous stone surgery, hospitalization, surgery duration, postoperative complication, stone length, stone location, stone density, stone number, lateralization, presence of hydronephrosis, and presence of preoperative stent datas of 518 patients who underwent RIRS in our clinic between January 2013 and January 2021 were retrospectively assessed. The patients were divided into two groups as successful and unsuccessful. The T.O.HO scores of all patients were calculated. Results The success rate was 72.5%. Compared to the unsuccessful group, stone length and stone density were lower, surgery duration was shorter and there were less lower pole stones in the successful group (p<0.001). No significant difference was found between the two groups in terms of the other parameters. The T.O.HO. score was significantly lower in the successful group compared to the unsuccessful group (p<0.001). According to the multivariate logistic regression analysis, stone length (OR: 0.905; 95% Cl: 0.866-0.946; p<0.001), lower pole location (OR: 0.546; 95% Cl: 0.013-0.296; p<0.001), stone density (OR: 0.999; 95% Cl: 0.998-1; p=0.044) and the T.O.HO. score (OR: 0.684; 95%Cl: 0.554-0.844; p<0.001) were found as the independent risk factors for RIRS success. ROC curve analysis showed that the T.O.HO. score could predict the RIRS success with 7.5 cut-off point (AUC:0.799, CI: 0.76–0.839; p<0.001). Conclusion The T.O.HO. score can predict RIRS success with a high rate of accuracy.

The role of calcium metabolism disorders in the formation of different density calculi with calcium oxalate nephrolithiasis

Objective To investigate the relationship between calcium metabolism disorders, stone formation inhibitor levels and stone density in primary and recurrent calcium-oxalate nephrolithiasis.Material and Methods Sixty nine patients with urolithiasis were examined, their average age was 41,4 ± 9,5 years. Two main groups were distinguished: Group 1 – primary calcium-oxalate nephrolithiasis (PN), Group 2 – recurrent calcium-oxalate nephrolithiasis (RN). Then each group was divided into two subgroups – A and B according to stone density: 500–1000 HU and from 1000–1500 HU, respectively. Stone density was determined by computed tomography (CT). PTH (parathormone), PTHrP (parathyroid hormone related protein), vitamin D, total blood calcium (Ca), ionized blood Ca, total blood protein, Ca and urine pH were also examined. After the examination, patients underwent surgical removal of the stones.Results It was found that 41.9% of group 1 and 46.9% of group 2 patients had grade I obesity. Average creatinine level in group 2 was 9.7% higher than in group 1 (p < 0.05). Urea level in both groups was not statistically significantly different. Glomerular filtration rate (GFR) was comparable. Groups 2A and 2B had higher PTHrP values (77.61 and 76.98 pg/mL, respectively) combined with relatively high PTH levels (2A – 4.4 pg/mL and 2B – 5.1 pg/mL), relatively low osteopontin concentration (2A – 0.044 pg/ mL, 2B – 1.106 pg/mL), compared to those in group 1 (p < 0.05). Pairwise unidirectional differences between groups 1A and 2A, 1B and 2B were found to correlate positively with density values: for osteopontin: r = 0.992 (p < 0.05); for vitamin D: r = 0.831 (p < 0.05); for blood Ca2+ ions: r = 0.836 (p < 0.05); for urine pH: r = 0.863 (p < 0.05). There was a negative correlation with the daily concentration of urinary calcium ions with the density of concrements: r = -0.663; p < 0.05. The concentration of osteopontin was significantly higher in Group 1B and 2B patients, and it was significantly lower in patients with stones of < 1000 HU density. Higher values of osteopontin concentration were noted in groups 1B and 2B in relation to groups 1A (p < 0.05) and 2A (p < 0.05). The increase of blood Ca2+ ions in patients in groups 1B and 2B in relation to groups 1A (p < 0.05) and 2A (p < 0.05) was also accompanied by higher values of vitamin D.Conclusion Patients with denser stones showed high values of osteopontin and PTHrP in serum and low values of urinary calcium ions, which may lead to the formation of concrements on the matrix with an organic base. Determination of calcium metabolism makes it possible to predict recurrence of KSD in primary calcium oxalate nephrolithiasis and assess the severity of mineral metabolism disorders in recurrent calcium oxalate nephrolithiasis.

The factors that affecting shockwave lithotripsy treatment outcome of kidney stones

Bacground: We aimed to analyze combination of the schockwave lithotripy (SWL) success predictors. Methods: In this retrospective study, the outcomes of the patients with kidney stones treated with SWL were analyzed. Adult patients (≥18 years) with complete records with non-contrast computed tomography (NCCT), stone analysis, laboratory data were involved in the study. Patients who were with urinary system anomalies, who were receiving alpha-blocker and/or calcium channel blockers and whom with impaired kidney function were excluded. The effect of stone density, skin-to-stone distance (SSD), perirenal tissue density (PTD), subcutaneous tissue density (STD), stone size, stone burden, stone localization, infundibulopelvic angle (IA), as well as body mass index (BMI) and stone analysis results on the success of the treatment was evaluated. Results: SSD, PTD, STD, stone localization, IA, as well as body-mass index, did not have any association with SWL success. Stone size and stone burden had a significant association with treatment success (p = 0.0001), and the cut-off values determined for stone size and stone burden were 12.95 mm (p = 0.0006) and 121.38 mm2 (p = 0.004) respectively. Stone density also had a significant association with treatment success (p = 0.0001), and the cut-off value determined for stone density was 739 HU (Hounsfield Unit) (p = 0.001). Treatment success was significantly lower in cystine and calcium oxalate monohydrate stones compared to other stone types (p = 0.019). Conclusion: Significant markers that determine SWL effectiveness are stone size, stone burden, stone density and, besides, stone type.

Prospective Single-Center Study of SuperPulsed Thulium Fiber Laser in Retrograde Intrarenal Surgery: Initial Clinical Data

<b><i>Introduction:</i></b> The objective of this study was to present our clinical experience of using the thulium fiber laser in retrograde intrarenal surgery (RIRS). <b><i>Methods:</i></b> A prospective clinical study performed after the IRB approval (Sechenov University, Russia). Patients with stones &#x3c;30 mm were treated with SuperPulsed thulium fiber laser (SP TFL) (NTO IRE-Polus, Russia) through a 200-μm-diameter fiber. Stone size, density, the duration of the operation, and laser on time (LOT) were measured. Based on the surgeon’s feedback, retropulsion and intraoperative visibility were also assessed (Likert scale). Stone-free rates (SFRs) were assessed with a low-dose CT scan 90 days after the operation. <b><i>Results:</i></b> Between January 2018 and December 2019, 153 patients (mean age 54 ± 2.8 years) underwent RIRS with SP TFL (mean stone density 1,020 ± 382 HU). Median stone volume was 279.6 (139.4–615.8) mm³. Median LOT was 2.8 (IQR 1.6–6.6) min with median total energy for stone ablation 4.0 (IQR 2.1–7.17) kJ, median ablation speed was 1.7 (1.0–2.8) mm³/s, median ablation efficacy was 13.3 (7.3–20.9) J/mm³, and energy consumption was 170.3 (59.7–743.3) J/s. Overall, the SFR (at 3 months) was 89%. The overall complication rate was 8.4%. Retropulsion was present in 23 (15.1%) patients. Visibility was estimated as optimal in most patients, with poor visibility reported in only 13 (8.5%) patients. <b><i>Conclusion:</i></b> The SP TFL is a safe and efficient tool in lithotripsy, irrespective of the stone type and density. Retropulsion is minimal and visibility is maintained with SP TFL. Nonetheless, further clinical studies are needed to ensure optimal comparison with conventional holmium:YAG lithotripsy.

The relationship between the stone-free status after extracorporeal shockwave lithotripsy (ESWL) treatment in different patient and kidney stone characteristics: A single center experience in Saudi Arabia

Purpose: The objective was to unveil the relationship between different relevant patient and kidney stone characteristics and the stone-free status post extracorporeal shockwave lithotripsy (ESWL) treatment. Materials and methods: Kidney stones cases referred for ESWL from October 2019 to January 2020 were collected. A total of 225 adult patients who met the criteria of being new cases of single radio-opaque kidney stones measuring 5 to 20 mm were included. We were looking for disintegrated stones down to 4 mm or less as a marker for stone-free (SF) status. The studied parameters were gender, laterality (right or left kidney), location of the stone within the kidney, stone’s density measured in Hounsfield units (HU), stone’s size, and stone-to-skin distance (SSD). Results: Out of the 225 cases treated, only 175 (77.8%) became SF after or during the study timeframe. SF status was achieved after the first session in 131 cases (58.2%). The bivariate analysis of the factors associated with higher SF rates found to be statistically significant were left kidney ( p-value of < 0.01), low stone density ( p-value of < 0.01), short stone–skin distance ( p-value of < 0.01), and small stone size ( p-value of < 0.01). On the other hand, gender and stone location within the kidney showed no association with ESWL outcomes. Conclusion: Kidney laterality, SSD, stone density, and size are influencing parameters on ESWL outcomes and achievement of stone-free status.

External validation of the R.I.R.S. scoring system to predict stone-free rate after retrograde intrarenal surgery

Background The R.I.R.S. scoring system is defined as a novel and straightforward scoring system that uses the main parameters (kidney stone density, inferior pole stones, stone burden, and renal infundibular length) to identify most appropriate patients for retrograde intrarenal surgery (RIRS). We strived to evaluate the accuracy of the R.I.R.S. scoring system in predicting the stone-free rate (SFR) after RIRS. Methods In our medical center, we retrospectively analyzed charts of patients who had, between September 2018 and December 2019, been treated by RIRS for kidney stones. A total of 147 patients were enrolled in the study. Parameters were measured for each of the four specified variables. Results Stone-free status was achieved in 105 patients (71.43%), and 42 patients had one or more residual fragments (28.57%). Differences in stone characteristics, including renal infundibulopelvic angle, renal infundibular length, lower pole stone, kidney stone density, and stone burden were statistically significant in patients whether RIRS achieved stone-free status or not (P < 0.001, P: 0.005, P < 0.001, P < 0.001, P: 0.003, respectively). R.I.R.S. scores were significantly lower in patients treated successfully with RIRS than patients in which RIRS failed (P < 0.001). Binary logistic regression analyses revealed that R.I.R.S. scores were independent factors affecting RIRS success (P = 0.033). The area under the curve of the R.I.R.S. scoring system was 0.737. Conclusions Our study retrospectively validates that the R.I.R.S. scoring system is associated with SFR after RIRS in the treatment of renal stones, and can predict accurately.