Verification of surgical factors affecting the efficiency of stone extraction with one-surgeon basketing technique using a f-URSL simulation model.

PURPOSE: Stone extraction is an important treatment option when performing flexible ureteroscopic lithotripsy (f-URSL) for upper urinary stones. We used a f-URSL simulator model to investigate surgical factors affecting the efficacy of stone extraction with the one-surgeon basketing technique. MATERIALS AND METHODS: This simulator-based study involved eight urologists and eight residents. These participants each performed two tasks, with Flexor (Cook Medical) and Navigator (Boston Scientific) ureteral access sheaths, with and without the M-arm (MC Medical) single-use basket holder, and with models representing both left and right kidneys. The two tasks were to touch each renal calix with the ureteroscope, and to extract stones. As outcomes, we recorded the number of times that the ureteroscope became stuck during insertion, the number of times a stone was dropped during removal, the number of times the basket forceps were opened and closed, and the time required to accomplish each task. RESULTS: The ureteroscope became stuck significantly more often when Navigator was used compared with Flexor overall, and for both urologists and residents (all p<0.01). Stones were dropped significantly more often on the ipsilateral side (kidney on the same side as the operator's hand) than on the contralateral side overall (p=0.01), and the basket forceps were opened and closed significantly more often on the ipsilateral side than on the contralateral side both overall and by residents (all p<0.01). CONCLUSIONS: The efficiency of stone extraction during f-URSL with the one-surgeon basketing technique was affected by differences in ureteral access sheath and the kidney side.

Effect of perioperative tamsulosin on successful ureteral access sheath placement and stent-related symptom relief: A double-blinded, randomized, placebo-controlled study.

PURPOSE: This study investigated the effect of administering tamsulosin before surgery on the successful insertion of a 12/14 French (F) ureteral access sheath (UAS) during the procedure, as well as the impact of preoperative and postoperative tamsulosin use on symptoms related to the ureteral stent. MATERIALS AND METHODS: This study was a randomized, single-center, double-blinded, placebo-controlled trial involving 200 patients who underwent unilateral retrograde intrarenal surgery. Patients received either tamsulosin (0.4 mg) or placebo 1 week before surgery until stent removal. Patients were randomly assigned to one of four groups. Group 1 received tamsulosin throughout the study period. Group 2 received tamsulosin before surgery and placebo after surgery. Group 3 received placebo before surgery and tamsulosin after surgery. Group 4 received placebo before and after surgery. The USSQ (Ureteral Stent Symptom Questionnaire) was completed between postoperative days 7 and 14 immediately before stent removal. RESULTS: A total of 160 patients were included in this analysis. Their mean age was 55.0±11.0 years, and 48 patients (30.0%) were female. In the group that received preoperative tamsulosin, the success rate of 12/14F UAS deployment was significantly higher than that of the preoperative placebo group (88.0 vs. 75.3%, p=0.038). Preoperative and postoperative tamsulosin did not significantly alleviate symptoms related to the ureteral stent. CONCLUSIONS: Our results revealed that preoperative administration of tamsulosin improved the success of larger-sized UAS, whereas preoperative and postoperative tamsulosin use did not significantly alleviate symptoms related to ureteral stents.

[Progress in Surgical Treatment of Upper Urinary Tract Stones in Children].

The incidence of urinary calculi in children has been increasing annually,and most of the cases are upper urinary tract stones.At present,surgery is the main way to treat upper urinary tract stones in children.With the gradual development of minimally invasive techniques in surgery,percutaneous nephrolithotomy,retrograde intrarenal surgery,and extracorporeal shock wave lithotripsy have become the main methods for treating upper urinary tract stones in children.We reviewed the current progress in surgical treatment of upper urinary tract stones in children and provided prospects for future treatment options.

FIRE Stones: impact of forced diuresis on the residual fragment rate after flexible ureteroscopy for destruction of kidney stones with laser-protocol for a randomized controlled two-parallel group multicenter trial with blinding evaluation.

BACKGROUND: Lithiasis is a common and recurrent disease. Flexible ureteroscopy (fURS) is the cornerstone of laser treatment of kidney stones. Kidney stones destruction requires its laser pulverization into small fragments in order to remove them through the ureter or improve their spontaneous expulsion along the urinary tract. However, most of the time, all the micro-fragments and dust created cannot be extracted using our surgical tools and may stay intra-renally at the end of the procedure. Adjuvant treatments (such as forced diuresis, inversion or mechanical pressure) were previously described to improve the expulsion of stone fragments after extra-corporeal shock wave lithotripsy. Nevertheless, the impact of adjuvant treatment after fURS remains unclear and mainly theoretical. OBJECTIVE: The primary objective is to show that the injection of 40 mg of furosemide in slow intravenous during 10 min, after the procedure, increases the stone-free rate 3 months after a fURS for destruction of kidney stones with laser. METHODS/DESIGN: The study will be a two-parallel group randomized, controlled, multicentric trial with a blinding evaluation. Nine French departments of urology will participate. Patients will be randomized in 2 groups: the experimental group (injection of 40 mg of furosemide at the end of the surgery) and a control one (usual care). Patients will be followed up for 3 months (± 2 weeks) after the surgery. Then, we will perform a low dose abdomino-pelvic CT scan. The primary outcome is the stone-free rate at 3 months. A centralized review of the images will be performed by two specialized radiologists, in a blind and crossed way to allow a homogenization of the results. The secondary outcomes will include the rate of early post-operative urinary tract infection (UTI), the evaluation of post-operative pain, and the safety of the use of furosemide in patients treated by fURS for renal stone laser destruction. As secondary objectives, it is also planned to look at the effect of the prescription of an alpha-blocker as usual treatment on stone-free rate and to assess the agreement between the imaging analysis of the urologist and the specialized radiologist. DISCUSSION: Lithiasis is a public health problem. It affects about 10% of the general population. This prevalence is increasing (multiplied by 3 in 40 years), partly due to changes in the population's eating habits over the years. The lithiasis patient is a patient with a chronic disease requiring annual follow-up and who may suffer from multiple recurrences, with a recurrence rate at 5 years of 50%. Recurrences are partly due to residual fragments left in the kidneys at the end of the operation. Other risk factors for recurrence include dietary hygiene and the presence of an associated metabolic disease. The metabolic blood and urine tests recommended by the Association Française d'Urologie (AFU) can be used to manage these last two problems. As far as residual fragments are concerned, their presence leads to an early recurrence of stones because they form the bed for a new aggregation of crystals in the kidneys. Being able to reduce the rate of residual fragments in patients with the use of furosemide at the end of the intervention therefore seems essential in the management of recurrences in our patients. This will also improve our patients' quality of life. Indeed, lithiasis disease leads to chronic pain associated with acute pain that motivates consultations to the emergency for specialized management. This study is the first to evaluate the impact of forced diuresis with the use of furosemide on the stone-free rate after a fURS for destruction of kidney stone with laser. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05916963 , first received: 22 June 2023. EU Clinical Trials Register EudraCT Number: 2022-502890-40-00.

Endourological society fellowship program: a real contribution to improve surgical outcomes of stone patients treated with ureteroscopy.

PURPOSE: We assessed the impact of the one-year endourological society fellowship program (ESFP) on the achievement of optimal surgical outcomes (OSO) in stone patients treated with ureteroscopy (URS). MATERIALS AND METHODS: We identified 303 stone patients treated with URS from January 2018 to June 2022 by five experienced surgeons (ES). Of those, two attended ESFP. OSO was defined as the presence of residual fragments ≤ 4 mm at 1-month post-operative imaging (Ultrasound + X - Ray or CT scan). Descriptive statistics explored patients' characteristics and the rate of OSO according to the attendance of ESFP. Uni- and multivariate logistic regression analyses (UVA and MVA) tested the impact of stone characteristics, surgical data, ESFP, and imaging technique on the rate of OSO. The LOWESS curve explored the graphical association between stone size and the multivariable-adjusted probability of OSO in the two groups of surgeons. RESULTS: Of 303 patients, 208 (69%) were treated by the two surgeons who attended ESFP. OSO was achieved in 66% and 52% of patients treated by ES with and without ESFP, respectively (p = 0.01). At UVA, ESFP (OR = 1.78; 95% CI = 1.09-2.90), stone diameter (OR = 0.92; 95% CI = 0.88-0.96), stone location (kidney vs. ureter; OR = 0.34; 95% CI = 0.21-0.58), imaging technique (CT scan vs. Ultrasound + X-Ray; OR = 0.28; 95% CI = 0.16-0.47) predicted OSO achievement (all p < 0.05). At MVA analyses, ESFP was associated with OSO (OR = 2.24; 95% CI = 1.29-3.88; p < 0.05), along with the other aforementioned variables. The LOWESS curve showed that the greater the stone size, the greater the difference in OSO in the two groups of surgeons. CONCLUSIONS: ESFP positively affects OSO achievement after URS, especially in patients with a high stone burden.

Impact of previously failed extracorporeal shock wave lithotripsy on ureterorenoscopy outcomes in upper urinary tract stones: a prospective comparative study.

OBJECTIVE: We sought to prospectively evaluate the impact of previously failed SWL on subsequent URS outcomes in the treatment of upper urinary tract stones. MATERIALS AND METHODS: Between May 2021 and May 2023, one hundred thirty-six patients with proximal ureteral stones < 1.5 cm and renal stones < 2.5 cm who were candidates for URS were prospectively assigned to a non-SWL group, which included patients without a history of failed SWL before URS, and a post-SWL group, which included patients with a history of failed SWL before URS. The success rate was the primary outcome. The perioperative data of the two groups were compared. RESULTS: The stone-free rate was 83.3% in the post-SWL group versus 81.3% in the non-SWL group, and 8.3% in the post-SWL group versus 9.4% in the non-SWL group had clinically insignificant residual fragments. There was no significant difference in the stone-free rate or success rate between the groups. No significant differences in intraoperative fluoroscopy time, operative time, intraoperative stone appearance, perioperative complications, or the presence of embedded fragments in the ureteral mucosa were detected between the two groups. CONCLUSION: Compared with patients who underwent primary URS, patients who underwent salvage URS for upper urinary tract stones had similar stone-free rates, success rates, operative times, fluoroscopy times, and complication rates without any significant differences.

Intraoperative computed tomography for detection of residual stones in endourology procedures: systematic review and meta-analysis

ABSTRACT Background: Success rates in endourological procedures, notably percutaneous nephrolithotomy (PCNL) and ureteroscopy (URS), have demonstrated suboptimal outcomes, leading to more reinterventions and radiation exposure. Recently, the use of intraoperative computed tomography (ICT) scans has been hypothesized as a promising solution for improving outcomes in endourology procedures. With this considered, we conducted a comprehensive systematic review and meta-analysis encompassing all available studies that evaluate the impact of the use of intraoperative CT scans on surgical outcomes compared to conventional fluoroscopic-guided procedures. Methods: This systematic review was conducted in accordance with PRISMA guidelines. Multiple databases were systematically searched up to December of 2023. This study aimed to directly compare the use of an ICT scan with the standard non-ICT-guided procedure. The primary endpoint of interest was success rate, and the secondary endpoints were complications and reintervention rates, while radiation exposure was also evaluated. Data extraction and quality assessment were performed following Cochrane recommendations. Data was presented as an Odds ratio with 95%CI across trials and a random-effects model was selected for pooling of data. Results: A comprehensive search yielded 533 studies, resulting in the selection of 3 cohorts including 327 patients (103 ICT vs 224 in non-ICT). Primary outcome was significantly higher in the experimental group versus the control group (84.5% vs 41.4% respectively, 307 patients; 95% CI [3.61, 12.72]; p<0.00001; I2=0). Reintervention rates also decreased from 32.6% in the control to 12.6% in the ICT group (OR 0.34; 95%CI [0.12,0.94]; p =0.04; I2= 48%), whereas complication rates did not exhibit significant differences. Radiation exposure was also significantly reduced in two of the included studies. Conclusion: This meta-analysis highlights a favorable outcome with intraoperative CT scan use in PCNL procedures, showing a considerable increase in SFR when compared to standard fluoroscopy and nephroscopy. Despite limited studies, our synthesis underscores the potential of ICT scans to significantly reduce residual stones and their consequences for endourology patients, as reinterventions and follow-up ionizing radiation studies.

Comparison of conventional (basketing + dusting) and Moses (pop-dusting) holmium lasers during flexible ureteroscopy in the treatment of renal stones between 2 and 3 cm: a randomized clinical trial.

To investigate the feasibility of conventional (basketing + dusting) and Moses (pop-dusting) holmium lasers during flexible ureteroscopy (FURS) in the treatment of 2-3 cm renal calculi and to compare the efficiency and safety of the two methods, a total of 230 patients with 2-3 cm kidney stones who underwent FURS were randomly divided into the conventional group and the Moses group. The mode of lithotripsy in the conventional group was fragmentation and dusting. The mode of lithotripsy in the Moses group was dusting and pop-dusting. Clinical and perioperative variables and complications were compared between the two cohorts. Multivariate analyses of factors contributing to the stone-free rate (SFR) and operation time were performed. No statistically significant differences were found in the demographics, renal stone-related data, SFR, or complications between the cohorts. The laser energy was higher in the Moses cohort than in the conventional cohort (119.3 ± 15.2 vs. 92.8 ± 15.1 kJ; P < 0.001), and the operation time was shorter in the Moses cohort than in the conventional cohort (99.5 ± 18.9 vs. 105.3 ± 13.7 min; P = 0.009). When there was isolated stone, the operation time was shorter in the Moses cohort than in the conventional cohort (99.6 ± 17.5 vs. 111.4 ± 10.7 min; P < 0.001), while there was no significant difference between the two cohorts when there were multiple stones (99.5 ± 20 vs. 101.2 ± 14 min; P = 0.415). Multivariate analyses found that an increase in stone volume can decrease the SFR and prolong the operation time, and use of a Moses laser can shorten the operation time. Both holmium laser modes during FURS can effectively treat 2-3 cm renal calculi. The Moses mode is recommended as the first choice for the treatment of isolated 2-3 cm renal stones. When treating multiple stones, the efficiency of these two laser modalities is the same. TRIAL REGISTRATION: ChiCTR2200056091.

Surgical Stone Trends from 2013 to 2021 in the US Medicare Population: Before and after the COVID-19 Pandemic.

Introduction and Objective: In early 2020, as the SARS-Cov-2 (COVID-19) pandemic progressed, many institutions limited nonurgent surgical care. This coincided with a decade-long trend of increasing percutaneous nephrolithotomy (PCNL) and ureteroscopy (URS) and decreasing shock wave lithotripsy (SWL) for surgical management of urolithiasis. Herein, we evaluate temporal stone surgery rates and surgeon volumes in the Medicare population and suggest how COVID-19 contributed to them. Methods: Retrospective analysis was conducted using the "Medicare Physician & Other Practitioners" database containing data from January 2013 to December 2021. Adult patients who underwent stone surgery were included. We evaluated surgeon characteristics and changes in case volumes over time adjusted for population. Results: In 2013, urologists performed 68,910 stone surgeries: SWL 42,903 (62%); URS 25,321 (37%); PCNL 686 (1%). Over the next 8 years, there was an average annual increase in URS (+13%) and PCNL (+13%) and decrease in SWL (-2%). In 2020, there was a 14% reduction in all stone cases: SWL (-25%); URS (-6%); PCNL (-8%). By 2021, case volumes recovered to pre-2020 levels, though SWL remained low: SWL 33,974 (34%); URS 64,541 (64%); PCNL 1764 (2%). From 2013 to 2021, the number of urologists performing SWL decreased (1718 to 1361) while URS and PCNL providers doubled (1,347 to 2,914 and 28 to 76, respectively). Conclusions: From 2013 to 2021, there was an increase in URS and PCNL and a decrease in SWL in the US Medicare population. The COVID-19 pandemic was associated with a decline in stone surgeries, particularly SWL. By 2021, PCNL and URS case numbers increased significantly with a smaller increase in SWL.

Vulnerability to Financial Toxicity From Stone Surgery.

PURPOSE: Financial toxicity has been described in stone formers however little is understood regarding its causes and how it may relate to stone surgery. We therefore aimed to longitudinally describe markers of financial strain in stone formers from the preoperative to postoperative time points. MATERIALS AND METHODS: A prospective cohort study was conducted from January 2022 to April 2023. Patients were enrolled in the waiting area prior to undergoing elective ureteroscopy or percutaneous nephrolithotomy. Participants completed the Commonwealth Fund's Biennial Health Insurance Survey at this time point and at 30 days postop. Items were pre-selected from the survey to capture markers of financial strain due to healthcare costs. RESULTS: One hundred nine participants were enrolled. Participants were a majority white (70%), college educated (62%), and privately ensured (72%). Despite these traditionally protective sociodemographic features, 42% of patients reported some marker of financial strain at the preoperative timepoint. Patients with Medicaid reported even higher financial stress (67%). Furthermore, 46% of patients did not know their deductible amount. Response rate was low at 30 days postop (35%) but suggested some patients were experiencing new financial strains. CONCLUSIONS: This paper shows that a significant proportion of stone patients are already displaying markers of financial strain from healthcare bills even prior to surgery as well as poor understanding of the costs they may incur. This makes them vulnerable to experiencing financial toxicity postoperatively and emphasizes the importance of understanding all contributing factors when developing future strategies to intervene in financial toxicity.

Being all-seeing gymnast within kidney cavity: analysis of the optical and flexibility characteristics trends of 61 flexible ureteroscopes over four decades.

The purpose of this review is to analyze the trend in optical features and flexibility changes of flexible ureteroscopes over the past decades, and determine the correlation of individual parameters with release period as well as with dimensional parameters. Flexible ureteroscopes mentioned in the literature or those commercially available were searched. To minimize the search bias, the instruments were grouped by release date time-periods of < 2000 year, 2000-2009, 2010-2019, and 2020 onwards. The final review included only those instrument models for which data on minimum and maximum depth of field, field of view, direction of view, and deflection degree had been determined. The correlation among features investigated as well as with release period was also determined. 61 models of flexible ureteroscopes (27 fibreoptic and 34 digital scopes) were included. Among the different features investigated among fiberoptic endoscopes, minimum depth of field positively and negatively correlated with channel size and field of view, respectively, whereas maximum depth of view and field of view positively correlated with overall shaft and deflection degree, respectively. Up and down deflection strongly correlated with each other and both were negatively proportional to the distal tip size. For the digital endoscopes, minimum depth of field negatively and positively correlated with distal tip size and working length, respectively. Maximum depth of field positively correlated with field of view, whereas the latter was negatively proportional to the overall shaft. As for the fiberoptic counterparts, up and down deflection strongly correlated with each other. Field of view, up and down deflection of fiberoptic flexible ureteroscopes, were significantly increased among fiberoptic and digital endoscopes over decades. As flexible ureteroscopy technology has evolved, there has been a trend towards increasing field of view with up and down deflection. Given the importance of scope ergonomics, one aspect of this popularity is the improvement of optical characteristics and deflection degree, which significantly correlates with the release period.

The Significance of Stone Culture in the Incidence of Sepsis: Results from a Prospective, Multicenter Study on Infections Post Flexible UreteroreNescopy (I-FUN) and Laser Lithotripsy for Renal Stones.

Objective: Sepsis is the most serious complication of flexible ureteroscopy (F-URS) and laser lithotripsy. We assessed the influence of positive stone culture (SC) on major infectious complications (sepsis, septic shock). Methods: This prospective study enrolled adult patients deemed suitable for F-URS and laser lithotripsy from nine centers (January 2022-August 2023). Inclusion criteria were as follows: kidney stone(s), preoperative midstream urine culture (MSUC), stone(s) assessed at computed tomography scan, and SC. Exclusion criteria were as follows: bilateral procedures, ureteral stones, and children. Group 1 included patients with sterile SC. Group 2 included patients with positive SC. Data are presented as median (interquartile range). A multivariable logistic regression analysis was performed to evaluate factors associated with having a positive SC. Results: In total, 293 patients were included. Median age was 51.0 (24) years. There were 167 (57.0%) males. Group 2 included 32 (2.5%) patients. Group 2 patients were significantly older [75.0 (14) vs 51.0 (23) years, p = 0.02]. Stone features were similar. Major infectious complications were higher in Group 2 (15.6% vs 0.4%). One patient died because of sepsis in Group 2. Two out of 6 (33.3%) patients with major infectious complications had the same pathogen in MSUC and SC. In the multivariable regression analysis, diabetes (OR 3.23), symptomatic urinary infections within 3 months before operation (OR 4.82) and preoperative stent/nephrostomy (OR 2.92) were factors significantly associated with higher odds of positive SC. Conclusions: Patients with positive SC have a higher incidence of major infectious complications after F-URS lithotripsy. SC should be performed whenever feasible because there is a poor correlation between MSUC and SC.

Can Machine Learning Correctly Predict Outcomes of Flexible Ureteroscopy with Laser Lithotripsy for Kidney Stone Disease? Results from a Large Endourology University Centre.

Background and objective: The integration of machine learning (ML) in health care has garnered significant attention because of its unprecedented opportunities to enhance patient care and outcomes. In this study, we trained ML algorithms for automated prediction of outcomes of ureteroscopic laser lithotripsy (URSL) on the basis of preoperative characteristics. Methods: Data were retrieved for patients treated with ureteroscopy for urolithiasis by a single experienced surgeon over a 7-yr period. Sixteen ML classification algorithms were trained to investigate correlation between preoperative characteristics and postoperative outcomes. The outcomes assessed were primary stone-free status (SFS, defined as the presence of only stone fragments <2 mm on endoscopic visualisation and at 3-mo imaging) and postoperative complications. An ensemble model was constructed from the best-performing algorithms for prediction of complications and for prediction of SFS. Simultaneous prediction of postoperative characteristics was then investigated using a multitask neural network, and explainable artificial intelligence (AI) was used to demonstrate the predictive power of the best models. Key findings and limitations: An ensemble ML model achieved accuracy of 93% and precision of 87% for prediction of SFS. Complications were mainly associated with a preoperative positive urine culture (1.44). Logistic regression revealed that SFS was impacted by the total stone burden (0.34), the presence of a preoperative stent (0.106), a positive preoperative urine culture (0.14), and stone location (0.09). Explainable AI results emphasised the key features and their contributions to the output. Conclusions and clinical implications: Technological advances are helping urologists to overcome the classic limits of ureteroscopy, namely stone size and the risk of complications. ML represents an excellent aid for correct prediction of outcomes after training on pre-existing data sets. Our ML model achieved accuracy of >90% for prediction of SFS and complications, and represents a basis for the development of an accessible predictive model for endourologists and patients in the URSL setting. Patient summary: We tested the ability of artificial intelligence to predict treatment outcomes for patients with kidney stones. We trained 16 different machine learning tools with data before surgery, such as patient age and the stone characteristics. Our final model was >90% accurate in predicting stone-free status after surgery and the occurrence of complications.

Outcomes and considerations for retrograde intrarenal surgery (RIRS) in the setting of multiple and large renal stones (>15 mm) in children: Findings from multicentre and real-world setting.

Purpose: The aim of this study is to evaluate the outcomes of retrograde intra renal surgery (RIRS) in the setting of large or multiple stones in children (<18 years). Materials and Methods: Retrospective analysis was performed of paediatric RIRS cases at nine centres worldwide over a 6-year period. Patients were divided into two groups: Group 1 had a single stone <15 mm. Group 2 had either multiple stones, maximum stone diameter of >15 mm, or both. Outcomes included stone free rate (SFR) and complications within 30 days. Results: In total, 344 patients were included with 197 and 147 in Groups 1 and 2, respectively. Ureteric access sheaths were more frequently used in Group 2 (39.5% vs. 56.8%, p = 0.021). The operation time was significantly longer in Group 2 (p < 0.001). SFR after a single procedure was 84.7% in Group 1 and 63.7% in Group 2. Overall complication rates in Groups 1 and 2 were 7.6% and 33.3%, respectively. The most frequently reported complication in both groups was post-operative fever (4.4% vs. 14%, p = 0.004). The rate of Clavien I/II complications in groups 1 and 2 was 6% and 25.1%, respectively (p < 0.05). The rate of Clavien ≥ III complications in groups 1 and 2 was 1.6% and 8.1%, respectively (p < 0.05). On multivariate analysis, total operation time, stone size and multiplicity were significant predictors of residual fragments. Conclusions: RIRS can be performed in paediatric cases with large and multiple stone burdens, but the complication rate is significantly higher when compared to smaller stones.

Development and Initial Evaluation of a Cost-Effective Force Sensor for Ureteroscopic Application.

Purpose: Retrograde intrarenal surgery is the gold-standard treatment for most kidney stones. During ureteroscopy, ureteral access sheath insertion at forces greater than 8.0 Newtons (N) risks high-grade ureteral injury. To monitor force, our institution utilizes a unique, Bluetooth-equipped device (i.e., the University of California-Irvine Force Sensor). Given the unique nature of the force sensor, we sought to develop an inexpensive and accessible force sensor based on Boyle's law and the specific amount of force required to compress an occluded 1.0 mL syringe. Materials and Methods: We evaluated three brands of 1.0 mL syringes. After setting the plunger at 1.0 mL, the syringe was occluded, and the syringe plunger was compressed. The syringe volume was recorded when the applied force on the plunger reached 4.0 N, 6.0 N, and 8.0 N. Multiple trials were performed to assess reliability and reproducibility. A method for applying this clinically was also developed. Results: The precise force thresholds identified for a 1.0 mL Luer-Lok™ Syringe (Becton Dickinson, Franklin Lakes, NJ) were 0.30 mL for 4.00 N, 0.20 mL for 6.00 N, and 0.15 mL for 8.00 N. The 1.0 mL Tuberculin Syringe and 1.0 mL Luer Slip Syringe were less precise, but compression from 1.0 to 0.40 mL, 0.25 mL, and 0.20 mL corresponded to force sensor readings that did not exceed 4.00 N, 6.00 N, and 8.00 N, respectively. Conclusions: Based on volume changes, 4.00 N, 6.00 N, and 8.00 N of force can be reliably and reproducibly achieved using an occluded 1.0 mL syringe.

Parapelvic Renal Cyst Treatment with Flexible Ureteroscopy: Single Centre Experience.

BACKGROUND: This study aimed to assess the feasibility, safety, and efficacy of an endoscopic parapelvic renal cyst (PRC) incision using flexible ureterorenoscopy (fURS). MATERIAL AND METHODS: We retrospectively reviewed data concerning 16 patients in whom PRC incisions had been performed using fURS between January 2016 and January 2022. Two patients were excluded from the study owing to a lack of follow-up information. The cysts of all the patients were evaluated preoperatively by computed tomography. The patients' age, gender, cyst size, presenting symptoms, postoperative complications, and pre- and post-treatment visual analogue scale (VAS) scores were evaluated. Surgical success was defined as a reduction of more than half of the cyst size in the sixth postoperative month. RESULTS: A total of 14 patients were included in this study. The patients' mean age was 52.6 ± 8.8 years, and the mean cyst size was 69.1 ± 15.5 mm. Twelve (85.7%) patients presented with flank pain. Clavien-Dindo grade 1 complications were observed in two patients (14.3%), and grade 2 complications were observed in one (7.1%). The median VAS scores were significantly lower after treatment than before in patients who presented with flank pain (2 (1-2.8) vs 8 (7-8), respectively; p = 0.002). Surgical success rate was detected in 11 patients (78.6%) six months after the treatment. CONCLUSIONS: Endoscopic incision of the PRC is a feasible treatment modality with high success rates and low complication rates. However, multicentre studies with larger populations and longer follow-ups are needed to evaluate the lasting effects.

Application Analysis of Low-Pressure Perfusion Combined with Occluder in Holmium Laser Lithotripsy for Patients with Middle and Upper Ureteral Calculi.

BACKGROUND: Ureteroscopic holmium laser lithotripsy has become one of the main methods of treating ureteral calculi. However, in the treatment of middle and upper ureteral calculi, ureteroscopy is difficult to operate owing to the high location of calculi. Thus, how to improve the treatment effect and reduce the stone migration has become the focus in clinical settings. On this basis, we evaluated the application effect of low-pressure perfusion combined with occluder in holmium laser lithotripsy for patients with middle and upper ureteral calculi. METHODS: This retrospective study selected 107 patients with middle and upper ureteral calculi who underwent low-pressure perfusion combined with ureteroscopic holmium laser lithotripsy from January 2021 to December 2022. We excluded 7 patients who did not meet the criteria, and ultimately included 100 patients. According to whether the occluder was used during the surgery, 100 patients were divided into groups A (n = 52, occluder) and B (n = 48, without occluder). The stone-migration rate during surgery, stone-clearance rate at 3 months after surgery, perioperative indicators, postoperative complication rate, and postoperative quality of life between the two groups were compared. RESULTS: The stone-migration rate in group A was significantly lower than that in group B, with statistically significant difference (p < 0.05). Both groups had no significant difference in stone-clearance rate at 3 months after surgery (p > 0.05). Group A had a significantly lower index of EuroQol (EQ) Five Dimensions Questionnaire and significantly higher score of EQ-Visual Analogue Scale than group B (all p < 0.001). CONCLUSIONS: Compared with the simple application of low-pressure perfusion, the combined application of low-pressure perfusion and occluder in ureteroscopic holmium laser lithotripsy can effectively reduce the stone migration and improve the postoperative quality of life.