What is the role of inflammatory markers in predicting spontaneous ureteral stone passage?

Purpose: To investigate the role of inflammatory markers in predicting the spontaneous passage of ureteral stones. Methods: We retrospectively reviewed 279 patients with ureteral stones sized 4–10 mm that were managed conservatively. The patients were divided into two groups: Group 1 consisted of 137 patients who passed the stone spontaneously; Group 2 comprised 142 patients without spontaneous stone passage. The groups were compared using the Mann-Whitney U and chi-square tests. In addition, univariate and multivariate analyses were performed to identify the significance of the parameters. Results: The mean age of the patients was 41.2 years. The patients in Group 1 had a significantly lower mean stone size, white blood cell count and neutrophil count. In addition, stone location, presence of hydronephrosis and history of urolithiasis were significantly different between the groups. Neutrophil percentage, neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio were insignificantly lower in Group 1. In a multivariate analysis, stone size, distal location and hydronephrosis status significantly predicted the spontaneous stone passage. However, inflammatory markers including white blood cell count, neutrophil count and neutrophil-to-lymphocyte ratio could not determine the likelihood of spontaneous stone passage. Conclusion: Our results suggest that inflammatory markers are no meaningful parameters for the prediction of spontaneous stone passage.

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.

A Systematic Review on Comparative Analyses between Ureteroscopic Lithotripsy and Shock-Wave Lithotripsy for Ureter Stone According to Stone Size

Background and Objectives: This systematic review and meta-analysis was conducted to analyze the treatment outcomes of shock wave lithotripsy (SWL) and ureteroscopic lithotripsy (URSL) according to the ureteral stone size. Materials and Methods: In this systematic review, relevant articles that compared SWL and URSL for treatment of ureteral stones were identified. Articles were selected from four English databases including Ovid-Medline, Ovid-EMBASE, the Cochrane Central Register of controlled Trials (Central), and Google Scholar. A quality assessment was carried out by our researchers independently using the Scottish Intercollegiate Guidelines Network (SIGN). A total of 1325 studies were identified, but after removing duplicates, there remained 733 studies. Of these studies, 439 were excluded, 294 were screened, and 18 met the study eligibility criteria. Results: In randomized control trial (RCT) studies, URSL showed significantly higher SFR than SWL (p < 0.01, OR= 0.40, 95% CI 0.30–0.55, I² = 29%). The same results were shown in sub-group analysis according to the size of the stone (<1 cm: p < 0.01, OR = 0.40, 95% CI 0.25–0.63; >1 cm: p < 0.01, OR = 0.38, 95% CI 0.19–0.74, I² = 55%; not specified: p < 0.01, OR = 0.43, 95% CI 0.25–0.72, I² = 70%). In the non-RCT studies, the effectiveness of the URSL was significantly superior to that of SWL (p < 0.01, OR = 0.33, 95% CI 0.21–0.52, I² = 83%). Retreatment rate was significantly lower in URSL than in SWL regardless of stone size (p < 0.01, OR = 10.22, 95% CI 6.76–15.43, I² = 54%). Conclusions: Meta-analysis results show that SFR was higher than SWL in URSL and that URSL was superior to SWL in retreatment rate. However, more randomized trials are required to identify definitive conclusions.

Laser lithotripsy using dusting technique (low energy, high frequency) for symptomatic upper urinary tract stones

Background A prospective study to assess the feasibility of stone dusting technique (low energy and high frequency) during laser lithotripsy in symptomatic upper urinary tract |(UUT) stones. Methods Sixty patients with symptomatic single or multiple UUT stones less than 3 cm in diameter were included. Patients with coagulation disorders and active UTIs were excluded. All patients were clinically evaluated and underwent non-contrast spiral CT (NCSCT) to detect stone site, size, number, Hounsfield unit. A rigid or flexible ureteroscope was used with stone dusting using the Ho: YAG laser at low-energy and high-frequency (0.5 J & 20 Hz) set. Operative and fluoroscopy time, total energy delivered, type of stent, hospitalization time, complications and its grade, and stone-free rate using NCSCT after 4 weeks were recorded. Results The mean stone size ± SD (range) was 1.55 ± 0.55 (0.5–3) cm; out of sixty patients (50 with single stone and 10 with multiple stones), fifty-five patients were stone-free at 4 weeks. Complications had occurred in 11 patients (eight with grade I, one with grade II, and two with grade IIIa) according to Clavien–Dindo grading of surgical complications. Stone size was the only parameter which correlated significantly with stone-free rate. No significant correlation was found between incidence of complications and other parameters (stone size, site, BMI, age and operative time). Conclusions Stone dusting technique is feasible, safe and effective in management of UUT stones.

Twinkle artifact in renal ultrasound, is it a solid point for the diagnosis of renal stone in children?

Background: Twinkle artifact, also known as color Doppler comet-tail artifact, occurs behind very strong, granular, and irregular reflecting interfaces such as crystals, stones, or calcification. This is visualized as a random mixture of red and blue pixels in the high-frequency shift spectrum located deep to the interface. Study results have suggested that the sonographic twinkling artifact may aid in the detection of renal stones with a variety of reference standard imaging modalities, including abdominal radiography, excretory urography, gray-scale sonography, and CT. Material and methods: Our retrospective observational study included children who had undergone abdomen/renal ultrasound for kidneys stones in our radiology department between 2013 and 2019. Presence of the twinkle artifact, and stone numbers and sizes were documented. CT examinations done <3 months prior to or after US were retrospectively assessed to confirm the presence of kidney stones as a reference standard. Results: Thirty-three abdominal renal US scans of 33 patients (21 males, 12 females) fulfilled the entry criteria. The interval between the US and CT was <3 months for all patients. The median overall age of the patients was 4 years (IQR: 3.125, range: 1– 165 months), The median number of days between the US and CT was 13 (IQR: 26, range: 0–81 days). US detected 33 hyperechoic foci suspected to be stones; 26 were confirmed as true positive (i.e. showed the twinkle artifact and were seen in CT), 4 were false positive (showed the twinkle artifact but were not seen in CT), and 3 were false negative (did not show the twinkle artifact but were seen in CT). The overall median stone size was 2 mm in the right kidney, and 5 mm in the left kidney (IQR: 6,11 mm), respectively. Twinkle artifact sensitivity was found to be 89.7% (95% CI 39.574%–90%). The twinkle artifact was assessed in all true-positive stones, determining a relatively high PPV of 26/29 (86.7%) for the twinkle artifact. The twinkle artifact was not dependent on stone size. Specificity for the twinkle artifact could not be calculated due to a lack of true negatives. Conclusion: The twinkle artifact is a sensitive US tool for detecting pediatric kidney and ureter stones, but with a small risk of false positive findings.

Immobilization of Providencia stuartii Cells in Pumice Stone and Its Application for N-Acetylglucosamine Production

Research background. Shrimp shells contain chitin that can further be processed into N-acetylglucosamine which has been extensively used to treat joint damage. Providencia stuartii isolated form previous research has strong chitinolytic activity and may be utilized in the form of immobilized cells to be used in repeated fermentation. Pumice is a porous and rigid stone that offers superior mechanical strength, making it suitable to be used for immobilization process. Experimental approach. The research used experimental method to conduct the submerged fermentation process with different pumice stone size and pumice stone:growth medium ratio (m/V). The fermentation was carried out for 4 days at 37 C and pH of 7.0. The optimum pumice stone size and pumice stone:growth medium ratio (m/V) were used to determine the optimum fermentation cycle to produce N-acetylglucosamine. Results and conclusions. Pumice stones of 1.0×1.0×1.0 cm and pumice stone:growth medium ratio (m/V) of 1:5 were found to be the optimum conditions which successfully immobilized (89.99±1.65) % cells and produced (331.37±7.34) g/L N-acetylglucosamine. The highest N-acetylglucosamine concentration of (322.97±2.46) g/L was obtained in the first fermentation cycle which then decreased and remained stable throughout the last three cycles of fermentation. Novelty and scientific contribution. P. stuartii was a strong chitinolytic bacteria previously isolated from rotten shrimp shells and was used for the first time in immobilized form to produce N-acetylglucosamine. The findings in this research showed potential use of P. stuartii cells immobilized in pumice stone for continuous production of N-acetylglucosamine using fermentation method.

Factors related to the spontaneous passage of common bile duct stones through the papilla: a single-center retrospective cohort study

Objective Common bile duct (CBD) stones can spontaneously pass through the papilla. This study explored factors associated with stone passage by comparing differences in the clinical features of stones retained in the CBD and excreted stones. Methods Data were retrospectively collected for all patients who were hospitalized in our center between March 2016 and May 2021 with clinical, laboratory, or imaging evidence of CBD stones. All patients underwent endoscopic retrograde cholangiopancreatography (ERCP) and were classified into two groups: group A (stones extracted by ERCP, n = 86) and group B (stones discharged before ERCP, n = 15). Demographic data, biochemical and radiological findings were compared between the groups. Results Stone size (0.82 vs. 0.33 cm), and levels of total bilirubin (58.2 vs. 28.8 μmol/L), gamma-glutamyl transpeptidase (416.7 vs. 193.9 U/L), alkaline phosphatase (191.9 vs. 123.1 U/L), carbohydrate antigen 19-9 (603.7 vs. 37.2 U/mL), and α-L-fucosidase (37.4 vs. 22.6 U/L) were significantly higher in group A than in group B. Logistic regression analyses showed that stone size was the only factor significantly associated with spontaneous passage of CBD stones. Conclusions CBD stones less than 0.33 cm in size may be self-expelled through the papilla.

Intraductal Fragmentation in Sialolithiasis Using Pneumatic Lithotripsy: Initial Experience and Results

Objective To report initial experience in using a pneumatic lithotripter to treat salivary stones. Study Design Level IV retrospective study. Setting University hospital and tertiary referral center. Methods A pneumatic lithotripter was used to treat salivary stones after these were diagnosed. Probes with diameters of 0.7 mm were used. Total fragmentation was intended in all stones. Stone fragments were removed using several instruments in serial sialendoscopies to achieve complete stone clearance. Results A total of 62 patients with 77 stones were treated. Forty-three submandibular stones were treated in 34 patients, and 34 parotid stones were treated in 28 patients. An operating pressure of 2.5 bar and a single frequency mode were used. Complete fragmentation was achieved in all but one of the treated stones in both glands (98.7%). Among the patients, 90.32% became stone free and 100% symptom free. Multiple stones were treated in 24.19% of the patients, and multimodal therapy was also carried out in 24.19%. All of the glands were preserved. Conclusions The pneumatic lithotripter proved to be effective in the treatment of sialolithiasis. Stone size, location, and the gland involved were important clinical factors. The device was sufficient to achieve success without any increased risk for complications in the patients or damage to the sialendoscopes.

Do we have a limit for retrograde intrarenal surgery for solitary kidney stone?

Objective: The management of urolithiasis in patients with a solitary kidney is challenging for urologists. This study aimed to evaluate the safety of retrograde intrarenal surgery (RIRS) in the treatment of stones in patients with solitary kidney and to reply to the question if there is any limit for this surgery. Methods: Between January 2016 and December 2019, we enrolled 52 patients who had a solitary kidney and underwent RIRS. We collected data on preoperative patient characteristics, stone dimensions, and postoperative outcomes. Stone size, duration of operation, duration of fluoroscopy, type of anesthesia, and degree of surgical complication were evaluated retrospectively. Surgeries performed in less and more than 60 minutes and with and without complications were compared. Results: A total of 52 patients with a kidney stone and a solitary kidney were evaluated. The mean stone size was 14 ± 0.4 cm and surgical success rate was 87.3%. In our study, 13 patients (24.5%) had grade 1 minor complications, and none required a blood transfusion. The mean operation time was 51.9 ± 17.3 minutes. The postoperative creatinine value increased in 6 patients. The duration of operation in the group with complications was significantly higher than that in the group without complications. In patients who underwent an operation lasting ≥ 60 minutes, stone size, fluoroscopy time, and complication rate were significantly higher than in patients who underwent an operation lasting ≤ 60 minutes. Conclusion: Our opinion is to be careful in patients with a solitary kidney with a big stone and we recommend assigning these procedure to experienced hands for not exceeding 60 minutes in one session.