The Use of Apnea During Ureteroscopy

Feasibility of respiratory synchronization for laser lithotripsy using a robotic retrograde intrarenal surgery system Zamenix™ in an in-vitro model

OBJECTIVES

This study aims to investigate the improvement of stone fragmentation efficiency and safety in robotic-assisted retrograde intrarenal surgery (RIRS) that implements the respiratory motion synchronization using an in vitro model.

MATERIALS AND METHODS

Laser lithotripsy was performed in three groups: manual procedure (group M), robotic procedures without respiratory synchronization (group RNR), and robotic procedures with respiratory synchronization (group RR). The study assessed fragmentation time, laser time, number of mucosal contacts, and total energy used. Two surgeons having different experience of conventional RIRS (> 2500 and < 500) were participated.

RESULTS

In overall results of the two surgeons, the fragmentation time significantly decreased to 74.8% in group RNR (P = 0.012) and 65.0% in group RR (P = 0.001), compared to group M. The laser time was significantly shorter in group RR compared to the group M (P = 0.003). The number of mucosal contacts was significantly reduced to 37.4% in group RNR (P = 0.048) and it was 34.0% in group RR, compared to group M. The total energy significantly decreased in group RR compared to group M (P = 0.011). There were no significant differences between group RR and RNR across all outcomes in the overall results of the two surgeons. For less experienced surgeon, the fragmentation time was significantly shorter in group RR compared to group RNR (P = 0.013).

CONCLUSIONS

Robotic-assisted RIRS resulted in reduced fragmentation time, laser time, mucosal contacts, and total energy compared to manual RIRS during laser lithotripsy. The incorporation of respiratory synchronization in robotic-assisted RIRS reduced laser time compared to manual RIRS and shortened the fragmentation time compared to the robotic-assisted RIRS without respiratory synchronization, particularly for less experienced surgeon. These initial results demonstrated the feasibility of robotic-assisted RIRS with respiratory synchronization, highlighting its potential to improve procedural efficiency and safety.

General anaesthesia with gated or controlled mechanical ventilation and its influence on peri and post operative outcomes of retrograde intra renal surgery when using flexible and navigable suction access sheath, an EAU-endourology and Global FANS collaborative study group: a prospective study

BACKGROUND

Retrograde intrarenal surgery (RIRS) is a preferred treatment for renal stones, yet challenges such as kidney movement due to respiration hinder surgical precision and outcomes. The introduction of flexible and navigable suction ureteral access sheaths (FANS) and novel techniques like gated respiration aim to improve stone-free rates (SFR) and reduce complications. This study evaluates the impact of gated respiration on perioperative outcomes in RIRS with FANS.

METHODS

A prospective multicenter study enrolled 562 adult patients undergoing RIRS with FANS under general anesthesia. Patients were divided into two groups: non-gated respiration (Group 1) and gated respiration (Group 2). Stone-free status (SFS) was assessed at 30 days using NCCT scans. SFS was defined as follows: grade A, zero fragments; grade B, a single fragment ≤ 2 mm; grade C, a single fragment 2.1-4 mm; and grade D, single/multiple fragments > 4 mm. Procedural efficiency, perioperative complications, and surgeon-reported outcomes were compared.

RESULTS

Patients in Group 2 had significantly higher zero residual fragment (Grade A) rates (64.2% vs. 59%) and overall SFR (Grade A + B: 98.3% vs. 91.3%, p = 0.001). Gated respiration improved sheath navigation (91.2% vs. 85.1%, p = 0.038) and visibility during lithotripsy (p = 0.004), while reducing complications like mild bleeding due to sheath movement (3.1% vs. 11.2%, p < 0.001). Logistic regression identified gated respiration as a significant predictor of SFS (OR 6.26, 95% CI 2.28-22.6, p < 0.001).

CONCLUSION

Gated respiration synergistically enhances the efficacy of FANS in RIRS, improving SFR, procedural safety, and surgeon experience. This study highlights the importance of respiratory control as an adjunct to RIRS, emphasizing the need for interdisciplinary collaboration between surgical and anesthesiology teams.

Does tidal volume during mechanical ventilation affect pediatric retrograde intrarenal surgery outcomes?

PURPOSE

The aim of the study was to analyze the effect of tidal volume during mechanical ventilation (MV) on pediatric retrograde intrarenal surgery (RIRS) outcomes.

METHODS

The data of patients who underwent RIRS between January 2018 and January 2023 were retrospectively analyzed. Patients under the age of 18 who underwent RIRS and whose data were available were included in the study. Patients were divided into two groups, ≤ 7 ml/kg (Group 1) and > 7 ml/kg (Group 2), according to the tidal volume during MV. Demographic data, clinical characteristics, and perioperative and postoperative data of the patients were statistically compared in both groups.

RESULTS

A total of 83 patients were enrolled, with a mean age of 6.9 ± 4.5 (1-17) years and a mean stone size of 11.7 ± 5.4 (5-33) mm. There were 31 patients in Group 1 and 52 patients in Group 2. The demographic data and clinical characteristics of the patients in both groups were comparable. There was no statistically significant difference between the two groups regarding stone-related (side, size, density, number, and location) and surgical (access sheath and basket use, operation time, fluoroscopy time, or postoperative stenting rates, complication rates) parameters. In the first month, the stone-free rate was higher in Group 1 than in Group 2 (90.3% vs. 71.1%, p = 0.03). No high-grade or anesthesia-related complications were observed in any of the patients.

CONCLUSION

Reducing tidal volume in pediatric RIRS may improve the stone-free rate by facilitating laser targeting and increasing operative field stability and surgical comfort.

Predictive Modeling Is a Reliable Indicator in Determining Excessive Renal Mobility Single-Center Randomized Study

Purpose: Excessive kidney mobility is an underestimating challenge for surgeons during retrograde intrarenal surgery (RIRS) and extracorporeal shock wave lithotripsy (ESL). There is no technique approved as a gold standard procedure for reducing excessive kidney mobility. The study aimed to uncover predictive factors for determining excessive renal mobility by utilizing clinicodemographic characteristics and noncontrast computed tomography (NCCT) data. Materials and Methods: The patients were categorized into two groups based on the presence of excessive renal mobility. Patients were scanned with a 16-channel, multislice NCCT, and images were captured utilizing a 16 × 1.25 mm collimation, 5 mm slice thickness. Many parameters including the origin angle of the renal artery, renal artery, vein length, diameter, the area and length of the psoas muscle, and perirenal and pararenal fatty tissue were measured on the images and analyzed. The data were analyzed using multivariate logistic regression, and the receiver operating characteristic curve model and we used predictive modeling based on three significant parameters. Results: Between May 2023 and May 2024, a total of 140 patients with and without excessive renal mobility enrolled into study. After multivariate analysis, increasing renal vein length and renal artery origin angle results in higher renal motility (odds ratio [OR]: 0.982; 95% confidence interval [CI]: 0.966-0.998; p = 0.030 and OR: 0.973; 95% CI: 0.948-0.999; p = 0.044; respectively). It also observed that an increase in tidal volume led to a reduction in renal mobility (OR: 1.015; 95% CI: 1.007-1.024; p = 0.001). Predictive modeling was designed based on these outcomes. This predictive modeling accurately estimates the presence of excessive renal mobility with improved 59% specificity and 65% sensitivity (p < 0.001, area under the curve 0.757; CI: 0.671-0.843). Conclusion: Physicians may predict the presence of excessive renal mobility via the predictive modeling mentioned in the current article. They may perform manipulations to reduce kidney mobility prior to ESL and RIRS.

Clinical Outcomes and Safety Assessment of Flexible Ureteroscopy as an Outpatient Procedure: A Retrospective Single-Center Study

Nephrolithiasis, or kidney stone disease, is a significant global health issue in urology, requiring effective management strategies. The management of nephrolithiasis through flexible ureteroscopy (fURS) is increasingly gaining acceptance; however, it is associated with significant costs related to consumables, pharmacotherapy, specialized equipment, and general anesthesia (GA). Limited resources and the need to optimize the cost effectiveness ratio have driven the shift to day-case procedures, offering financial and operational benefits and improving patient satisfaction. This outpatient care approach addresses clinical and economic challenges. For same-day discharge, spinal anesthesia (SA) is essential for fURS, as GA does not permit safe immediate discharge. This retrospective study investigates the feasibility of same-day discharge following fURS procedures performed under SA. Analyzing data from 401 patients who underwent 414 fURS procedures between January 2020 and December 2023, this study aims to evaluate whether same-day discharge is a viable option compared to conventional fURS under GA. The primary objectives are to assess the outcomes, including efficacy, stone-free rate (SFR), pain management, and complication rates, in the context of same-day discharge. Additionally, this study seeks to identify patient and kidney stone characteristics that may influence the suitability of one-day fURS under SA. Outcomes will be measured using the Dindo-Clavien (D-C) classification and Visual Analog Scale (VAS) scores post-procedure.

The Effect of Anesthesia Type on the Stability of the Surgical View on the Monitor in Retrograde Intrarenal Surgery for Renal Stone: A Prospective Observational Trial

Background and Objectives: Retrograde intrarenal surgery (RIRS) is a minimally invasive technique for nephrolithiasis. RIRS is performed via a monitor screen displaying a magnified surgical site. Respiration can affect the stability of the surgical view during RIRS because the kidneys are close to the diaphragm. The purpose of this trial is to compare the effect of anesthesia type on the stability of the surgical view during RIRS between spinal anesthesia and general anesthesia. Materials and Methods: Patients were allocated to the general anesthesia group or spinal anesthesia group. During surgery, movement of the surgical field displayed on the monitor screen was graded by the first assistant on a 10-grade numeric rating scale (0-10). Next, it was also graded by the main surgeon. After surgery, we evaluated the discomfort with the anesthesia method for all patients. Results: Thirty-four patients were allocated to the general anesthesia group and 32 patients to the spinal anesthesia group. The average values of the two surgeons for surgical field oscillation grade showed vision on the monitor screen was more stable in the general anesthesia group than the spinal anesthesia group (3.3 ± 1.6 vs. 5.0 ± 1.6, p < 0.001). The degrees of the inconvenience of the surgery did not differ between the groups (0.7 ± 1.8 vs. 1.6 ± 2.6, p = 0.114), even though more patients reported inconvenience with a grade of 3 or more in the spinal anesthesia group (8.8% vs. 28.1%, p = 0.042). Conclusions: In terms of the visualization of the surgical site, general anesthesia might provide a more stable surgical view during RIRS compared to spinal anesthesia without increasing inconvenience induced by the type of anesthesia.

Sedation vs. general anesthesia in stone ureteroscopy: Comparison of efficacy and safety, a post COVID-19 report

INTRODUCTION

Ureterorenoscopy (URS) for ureteral or renal stones is traditionally performed under general anesthesia (GA). Sedation is an alternative to GA, allowing control of the level of consciousness, spontaneous ventilation, and faster recovery. Our aim was to compare sedation and GA for patients undergoing ureterorenoscopy. Endpoints were stone-free rate (SFR) and complication rates.

METHOD

Monocentric comparative retrospective study including all consecutive ureterorenoscopies for ureteral or renal stone. The inclusion period was dichotomized in two 6-months periods due to the COVID-19 pandemic: from January 1 to July 1, 2019 (URS under GA) and from January 1 to July 1, 2021 (URS under GA or sedation). Stone-free (SF) status was defined as the absence of stone or fragment>4mm after the first ureterorenoscopy. Complication rates were assessed according to the Satava (perioperative complications) and Clavien-Dindo (postoperative complications) classifications. Statistical analysis was performed by Chi-square test.

RESULTS

A total of 185 patients were included for a total of 206 ureterorenoscopies; 82 underwent ureterorenoscopy under GA and 103 under sedation. The median stone size was 10 [7-16] mm. In all, 150 (81%) patients had at least one intrarenal stone. The SFR was similar between the two groups (67% GA group, 69% sedation group, P=0.912). In the sedation group, the mean SFR in ureter was 83.7% vs. 92.5% in the GA group. In renal cavities, the mean SFR was 46.4% in the sedation group vs. 42.5% in the GA group. Satava grade I, IIa, and IIb complications were 5 (6%), 5 (6%), and 1 (1%) in the GA group and 6 (6%), 1 (1%), and 3 (3%) in the sedation group, respectively (P=0.214). The grade I, II, III, and IV Clavien complications were 6 (7%), 3 (4%), 0 (0%), and 2 (2%) in the GA group and 6 (6%), 4 (4%), 1 (1%), and 4 (4%) in the sedation group, respectively (P=0.928).

CONCLUSION

Our post COVID-19 study showed no difference in efficacy and safety between ureterorenoscopy under sedation and GA for patients with renal stones. Our results confirm the interest of the sedation procedure, particularly in the context of outpatient surgery.

LEVEL OF EVIDENCE: 4

Does High Ventilation Mode Affect the Success Rates of Retrograde Intrarenal Surgery? A Single-Blind Randomized, Prospective, Single-Center Study

Purpose: Retrograde intrarenal surgery (RIRS) has been accepted as a first-line therapeutic option for kidney stones <2 cm. Renal mobility might be a challenging situation for the surgeon targeting the laser, thereby limiting the renal mobility during surgery might affect the surgical success. The main objective of the present trial was to evaluate the effect of two different ventilation modes on the efficacy and safety of RIRS performed under general anesthesia. Materials and Methods: The patients undergoing RIRS from January 2023 to April 2023 were prospectively enrolled in the trial. In the standard ventilation (SV) mode, the tidal volume was 8 to 10 mL/kg with respirations per minute being 10-15, whereas in the high ventilation (HV) mode the tidal volume was reduced to 6 to 8 mL/kg with the frequency being increased to 15 to 18 respirations/minute. For the purposes of the trial and the randomization, the anesthesiologist was informed about the ventilation mode used, whereas the surgeon was blinded. The surgical success rates and the observed complications were compared between SV and HV modes. Results: A total of 144 patients were enrolled with the mean age 48.78 ± 14.16 years. The mean duration of operation was 62.9 ± 26.3 minutes in the SV group, whereas it was 58.4 ± 20.1 minutes in the HV group (p = 0.031). Fragmentation rate of the stones per minute was higher in the HV group with the difference being statistically significant (p = 0.003). In the preoperative period, while hematuria was seen at higher rates in the HV group, the difference was not statistically significant (p = 0.671). Stone-free rates (Grades A-B-C) and the rates of postoperative complications were comparable between the groups (p = 0.605 and p = 0.676, respectively). Conclusion: Using HV mode during the RIRS decreased the operative time and provided the surgeon with the ability to target the laser more effectively. Surgeons might prefer using the HV mode during RIRS in a mobile kidney to reduce their operative time and perform comfortable surgery. ClinicalTrials.gov: The trial is registered at ClinicalTrials.gov with the registration number of NCT05792670.

Outcomes of Retrograde Intrarenal Surgery Performed Under Neuraxial vs. General Anesthesia: An Updated Systematic Review and Meta-Analysis

Background

The current review aimed to assess if the outcomes of retrograde intrarenal surgery (RIRS) differ with neuraxial anesthesia (NA) or general anesthesia (GA).

Methods

The databases of PubMed, Embase, CENTRAL, ScienceDirect, and Google Scholar were searched up to 3rd December 2021 for randomized controlled trials (RCTs) and observational studies comparing outcomes of RIRS with NA or GA.

Results

Thirteen studies involving 2912 patients were included. Eight were RCTs while remaining were observational studies. Meta-analysis revealed that stone free status after RIRS did not differ with NA or GA (OR: 0.99 95% CI: 0.77, 1.26 I2 = 10% p = 0.91). Similarly, there was no difference in operation time (MD: -0.35 95% CI: -4.04, 3.34 I2 = 89% p = 0.85), 24 h pain scores (MD: -0.36 95% CI: -0.96, 0.23 I2 = 95% p = 0.23), length of hospital stay (MD: 0.01 95% CI: -0.06, 0.08 I2 = 35% p = 0.78), Clavien-Dindo grade I (OR: 0.74 95% CI: 0.52, 1.06 I2 = 13% p = 0.10), grade II (OR: 0.70 95% CI: 0.45, 1.07 I2 = 0% p = 0.10) and grade III/IV complication rates (OR: 0.78 95% CI: 0.45, 1.35 I2 = 0% p = 0.37) between NA and GA. Except for grade I complications, the results did not change on subgroup analysis based on study type and NA type.

Conclusion

Our results suggest that NA can be an alternative to GA for RIRS. There seem to be no difference in the stone-free rates, operation time, 24-h pain scores, complication rates, and length of hospital stay between NA and GA for RIRS. Considering the economic benefits, the use of NA may be preferred over GA while taking into account patient willingness, baseline patient characteristics, and stone burden.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42021295407.

Flexible Ureterorenoscopy under Spinal Anesthesia: Focus on Technique, Results, Complications, and Patients' Satisfaction from a Large Series

INTRODUCTION

Although spinal anesthesia (SA) may reduce postoperative morbidity, most urologists perform flexible ureterorenoscopy (fURS) under general anesthesia (GA). The objective of our study is to provide technical details, results, complications, and patients' satisfaction with fURS performed under exclusive SA.

METHODS

We analyzed all consecutive fURS performed under SA to treat renal stones from March 2011 to February 2017. Details of technique, operative time, outcomes, need for further treatments, complications, and patients' satisfaction were evaluated.

RESULTS

Two hundred thirty-four fURS under SA were considered. SA was performed through L2-L3 vertebral interspace in 64.1%. Patients were discharged the same day of surgery. Mean stone burden was 13.5 ± 6.6 mm and mean operative time 76.9 ± 34.6 min. Single-procedure SFR was 69.7%. Further treatments were performed in 22.8%. 96.6% had no anesthesia-related complications. No Clavien-Dindo grade ≥ IIIb complications were noticed. 99.6% of patients were satisfied with SA. No cases of conversion from SA to GA occurred.

CONCLUSION

fURS can be performed safely and efficiently under SA, taking into account a few details of the technique. Patients' satisfaction with SA is very high, and complications are rare. Although SA is usually adopted in unfit patients for GA, it may be considered as a viable alternative in fit patients.

Ergonomics and Surgeon Comfort During Flexible Ureteroscopy

The technological advancements of flexible ureteroscopy (FURS) and its accessories have resulted in broadening its indications to include the management of complex renal stones, with long operative time. The surgeon's understanding about the ergonomics of the ureteroscopes and their cognizance of the operation theatre layout helps to improve their performance, including the surgical outcomes. This paper will describe the ergonomics that are involved in conducting FURS which in turn will aid in developing a more conducive surgical environment for the surgeon during the procedure, based on scientific literature review and expert opinions in high-volume centres. Proper surgeon position, well-arranged operation theatre layout, monitor and pedal position, anaesthesia type, and surgical team are important factors to decrease musculoskeletal strains for surgeons and increase work efficiency. Different types of flexible ureteroscope have different characters and knowing these special characters leads to better ergonomics during surgery. Robotic-assisted FURS have shown good safety and ergonomics in clinical application.

Spinal versus general anesthesia during retrograde intra-renal surgery: A propensity score matching analysis

Background:

The indications for retrograde intra-renal surgery (RIRS) have greatly increased, however, there is still no consensus on the use of spinal anesthesia (SA) during this procedure. The aim of this study was to evaluate the comparability of surgical conditions and outcomes with RIRS performed under SA versus general anesthesia (GA) for renal stones.

Materials and methods:

This was a prospective, observational study in patients scheduled for RIRS in a single teaching hospital in Italy. Inclusion criteria were age >18 years and the presence of single or multiple renal stones. We recorded information concerning the site of lithiasis, the number of calculi, total stone burden, and the presence of concomitant ureteral stones or hydronephrosis. A propensity score-matched analysis was performed to evaluate the results in terms of surgical outcome, intraoperative and postoperative complications, and analgesia demand balanced for confounding factors. Patients were followed-up until day 90 from discharge.

Results:

We included 120 patients, the propensity score-matched cohort included 40 patients in the SA and 40 in the GA groups. The stone-free rate was 67.5% in the GA group and 70.0% in the SA group (p = 0.81). The use of auxiliary procedures within 90 days did not differ between groups (25.0% vs. 22.5%, p = 0.79). No cases of conversion from SA to GA were recorded. We did not find any differences in intraoperative bleedings, perforations, and abortions. Complication rates were similar in the 2 groups (10.0% in GA vs. 5.0% in SA, p = 0.64).

Conclusions:

In our cohort, RIRS performed under SA and GA was equivalent in terms of surgical results and complications.

Endoscopic management of upper tract urothelial carcinoma-tips and tricks

Ureteroscopic methods have been rapidly evolving in the last several decades. With advances in flexible devices, optics and laser technologies, the endourologic surgeon has now the tools to treat high-volume tumors, in difficult locations, with good oncologic outcome. This makes radical nephroureterectomy unnecessary in some cases. Endoscopy in the setting of UTUC will surely continue to evolve and become applicable to a wider selection of patients. In this review we describe the surgical technique and provide tips and tricks which we use in our practice of endoscopic retrograde treatment of upper-tract urothelial carcinoma.

Semirigid Ureteroscopy: Step by Step

This article aims to demonstrate a step-by-step technique of semirigid ureteroscopy (URS) for the treatment of ureteral stones, urothelial tumors, and ureteral stenosis. Operating room setup, camera settings, access to the bladder, and negotiation of the ureteral orifice, lasertripsy, basketing of the stone fragments, endoscopic treatment of ureteral tumors and ureteral stenosis, flexible URS at the end of semirigid URS, and Double-J stent placement are described step by step.

Influence of anesthesia methods on surgical outcomes and renal function in retrograde intrarenal stone surgery: a prospective, randomized controlled study

BACKGROUND

We analyzed the influence of anesthesia methods on surgical outcomes and renal function in retrograde intrarenal surgery (RIRS) in a prospective, randomized controlled study.

METHODS

Seventy patients who underwent RIRS from September 2015 to February 2017 were randomly allocated to general anesthesia (GA) or spinal anesthesia (SA) groups. Renal function was assessed using estimated glomerular filtration rate, and separate renal function was evaluated using nuclear medicine tests. Maneuverability and accessibility were evaluated after every surgery. All procedures were performed by a single experienced surgeon (SY Cho).

RESULTS

Stone-free rate was higher in the GA (92.3%, 36 of 39) than the SA (71.0%, 22 of 31) (P = 0.019) group. Pain score was higher in the GA than in the SA group on the first postoperative morning (P = 0.025), but pain scores of the two groups were similar before discharge (P = 0.560). There were no differences in the changes of serum creatinine level (P = 0.792) and changes of estimated glomerular filtration rate (P = 0.807). Differences of separate renal function between operative and contralateral site increased significantly in patients under GA than under SA at postoperative 3 months (P = 0.014). Maneuverability and accessibility were better in SA with sedation than GA (P < 0.001).

CONCLUSIONS

RIRS under SA showed advantages in renal function change using renogram at postoperative 3 months and in lower pain score on the first postoperative morning. Performance of operator under SA was worse than that under GA and significantly improved with sedation. RIRS under SA showed advantages in lower pain score at postoperative first day.

TRIAL REGISTRATION

Clinicaltrials.gov ID is NCT03957109, and registration date is 17th May 2019. This study was retrospectively registered.

Reducing kidney motion: optimizing anesthesia and combining respiratory support for retrograde intrarenal surgery: a pilot study

BACKGROUND

One of the greatest challenges presented with RIRS is the potential for movement of the stone within the operative field associated with diaphragm and chest respiratory excursions due to mechanical ventilation. To overcome this challenge, we propose in this pilot study a new general anesthesia technique combining high frequency jet ventilation (HFJV) with small volume mechanical ventilation (SVMV). Data regarding safety, feasibility and surgeons' impression was assessed.

METHODS

Patients undergoing RIRS for kidney stones from November 2017 to May 2018 were prospectively recruited to participate in the study. In each case after the beginning of general anesthesia (GA) with mechanical ventilation (MV) surgeons were asked to assess the mobility of the operative field and conditions for laser lithotripsy according to the developed questionnaire scale. The questionnaire consisted of 5 degrees of assessment of kidney mobility and each question was scored from 1 to 5, 1 being very mobile (extremely poor conditions for dusting) and 5 completely immobile (Ideal conditions for dusting). After the assessment GA was modified with combined respiratory support (CRS), reducing tidal volume and respiratory rate (small volume mechanical ventilation, SVMV) and applying in the same time transcatheter high frequency jet ventilation (HFJV) inside the closed circuit. After beginning of CRS, surgeons were once again asked to assess the mobility of the operative field and the conditions for laser lithotripsy. Main ventilation parameters were recorded and compared in both regimens.

RESULTS

A total of 38 patients were included in the study. The mean age was 49 (range 45-53) with a mean stone size of 10 mm (range 10-14) and Hounsfield unit of 1060 (range 930-1190). All patients underwent successful RIRS and no intraoperative complications occurred throughout the duration of the study. A statistically significant difference between ventilation parameters prior to and after CRS institution was detected in all cases, however their clinical impact was negligible. Despite this, assessment via the questionnaire scale point values varied significantly before and after the application of CRS and were 2.3 (2.1; 2.6) and 3.8 (3.7; 4.0) respectively (p < 0.001).

CONCLUSIONS

The novel combined respiratory approach consisting of HFJV and SVMV appears to provide better conditions for stone dusting through reduced respiratory kidney motion and is not associated with adverse health effects or complications.

TRIAL REGISTRATION

NCT03999255 , date of registration: 25th June 2019 (retrospectively registered).

Retrograde intrarenal surgery for stone disease under spinal anaesthesia, a minimally invasive technique. A retrospective analysis of 1,467 cases

INTRODUCTION AND OBJECTIVES

The aim of the present study was to compare RIRS procedures applied under general anaesthesia (GA) and spinal anaesthesia (SA) regarding success and complication rates.

MATERIALS AND METHODS

A retrospective evaluation was conducted with the data obtained from patients treated with RIRS under SA and GA at 2centres from October 2014 until January 2018. The SA and GA groups were evaluated according to the parameters of stone-free and complication rates, postoperative pain control and length of in-hospital stay. The stone-free rates from the RIRS procedures applied with SA were evaluated by the surgeons who participated in the study.

RESULTS

A total of 1361 patients were included in the study. A stone-free rate of 84.4% was obtained in the global results: 85.3% in the SA group and 83.5% in the GA group (P=.364). No statistically significant difference was determined regarding surgeons who practiced RIRS under SA with respect to success/complication rates and operating time (P=.676). Operating time was determined as 44.2±14.2 mins in the SA group and 49.7±19.1 mins in the GA group (P=.014).

CONCLUSIONS

The RIRS method can be applied safely, either under spinal anaesthesia, or under general anaesthesia. The success of RIRS under spinal anaesthesia has been shown as an independent factor regarding surgeon. It can be considered a good alternative to general anaesthesia.

Toward Respiratory-Gated Retrograde Intrarenal Surgery: A Prospective Controlled Randomized Study

INTRODUCTION

We set out to investigate whether general anesthesia with low ventilation (LV, respiratory rate ≤8/minute and tidal volume <500 mL) could reduce renal mobility and thereby facilitate improved retrograde intrarenal surgery (RIRS) compared with general anesthesia with standard ventilation (SV).

MATERIALS AND METHODS

All 60 consecutive patients who presented for RIRS in our department from September 1, 2017 to December 31, 2017 were prospectively randomized 1:1 into one group that was selected to receive SV and another that received LV. Significant factors influencing the study endpoints considered fragmentation rate (FR), removal rate (RR), processing rate (PR), and operating rate (OR), were statistically analyzed for the whole group as well as for comparison by level of surgeon expertise.

RESULTS

Univariate analysis revealed that LV was a significant factor in improving all endpoints. Some endpoints were also affected by the stone's volume, number, and density as well as the surgeon expertise. LV remained the single independent factor for FR, RR, and PR in the multivariate analysis. LV significantly improved all four of the fellows' endpoints (p < 0.05 for each) and positively influenced the expert's RR (p = 0.04), PR (p = 0.02) and OR (p = 0.04). The performance gap between the fellows and the experts narrowed under LV. The end-tidal CO₂ was significantly higher in the LV group (50 vs 36 mm Hg; p < 0.0001), however, without any clinical significance. The overall stone-free rate (97%) and complication rate (5%) were not significantly different between the two groups. The patient's anesthesia-related safety was not affected by the mode of ventilation as evidenced by no need to convert from LV to SV during the procedures.

CONCLUSIONS

LV during RIRS has a significant positive impact on the overall improvement of surgical performance and effectiveness. It does not negatively affect the patient's anesthesia-related safety and may contribute to considerably improving the performance of in-training endourologists.

Could spinal anesthesia be a choice for retrograde intrarenal surgery

Objective:

In this study, we aimed to compare cases of retrograde intrarenal surgery performed under spinal or general anesthesia through investigating relevant parameters for the first time in the literature.

Material and method:

In total, 86 patients with diagnosis of kidney stone who were treated by retrograde intrarenal surgery were included in this randomized controlled prospective study. In total, 43 of these operations were performed under spinal anesthesia (group I) and 43 were performed under general anesthesia (group II). The groups were compared in terms of demographic features, American Society of Anesthesiologists score, duration of operation, complication rates, postoperative visual analogue scale, postoperative hospitalization period, stone-free rates, and cost value ratios.

Results:

There were no significant differences between the two groups in terms of demographic findings, preoperative stone loads, postoperative stone-free rates, complication rates and postoperative hospitalization periods (p > 0.05). Postoperative visual analogue scale scores and cost value ratios were found statistically significantly lower in the spinal anesthesia group (group I) when compared with the general anesthesia group (group II; p < 0.001).

Conclusion:

Performing retrograde intrarenal surgery in the presence of spinal anesthesia is equally effective with general anesthesia. Spinal anesthesia also appears to be a more advantageous method due to statistically significantly lower mean postoperative pain scores and treatment cost value ratios.

Flexible ureteroscopy: technique, tips and tricks

During the last decades, the surgical management of kidney stones benefited of many technological advances and one of them is the development of flexible ureteroscopy (fURS). This tool, ancillary equipment such as graspers and baskets, and lithotripsy technique with Holmium:YAG laser underwent many improvements leading to a widening of its indications with diagnostic and therapeutic management of upper urinary tract pathologies such as urolithiasis and urothelial tumors. The objective of this review is to describe the surgical technique for fURS as well as tips and tricks for the treatment of renal stones.

Semi-rigid ureteroscopy: indications, tips, and tricks

Advances in ureteroscopic technology, alongside broadening treatment options have fuelled the rapid expansion of endourology. Semi-rigid ureteroscopy is a well-known procedure used globally for varying urological conditions, with high success rates. This article aims to provide ‘tips and tricks’ for the semi-rigid ureteroscopy procedure, and the management of commonly encountered pathology such as renal stones, ureteric strictures, and urothelial tumours.

RIRS in the elderly: Is it feasible and safe?

BACKGROUND

The aim of this study was to compare the safety and efficacy of RIRS in men ≥65 years to those <65 years.

MATERIALS AND METHODS

Patients who underwent RIRS were prospectively collected from March 2013 to March 2014 in 5 European centers. Perioperative outcomes and complications in elderly men were compared with men <65 years. Univariable and multivariable analyses were performed for factors predicting overall complications. The groups were compared using Mann-Whitney U test. Categorical variables were compared using chi-squared test and the Yates correction or the Fisher's exact test.

RESULTS

A total of 399 patients with renal stones were included, 308 (77.19%) were aged <65 years, 91 (22.8%) were aged ≥65 years. Elderly patients were more likely to have higher ASA scores (35.7% vs 92.3%; p < 001), Charlson Comorbidity Index (1.8 vs. 5.2, p < 0.001), hyperlipidemia (10.06% vs. 30.76%; p = 0,0005) and coronary heart disease (5.51% vs. 17.58; p = 0.005) compared to younger cohort. Perioperative outcomes (stone free rate, operative time and re-intervention rate) did not show differences between the two groups (p > 0.05). Surgical and medical complication rates were similar between the cohorts (14.28% vs 9.89%; p = 0.38). Multivariate analysis did not identify any predictive factors of complications among the two groups (p > 0.05).

CONCLUSIONS

In this study, elderly RIRS patients had comparable short term efficacy and perioperative complications to younger patients, despite a higher prevalence of comorbidity. Age itself should not be considered as a risk factor for the development of complications in patients undergoing RIRS for renal stone.