Complications of retrograde intrarenal surgery classified by the modified Clavien grading system

Is fluoroless retrograde intrarenal surgery safe and feasible in uncomplicated ureteral and renal stones? A single-center large series study

INTRODUCTION

Aimed to investigate the feasibility and availability of fluoroless retrograde intrarenal surgery (fRIRS) in a large patient population.

METHODS

Patients who underwent fRIRS for ureteral or renal calculi in our center between June 2019 and June 2024 were reviewed. Demographic data, stone characteristics, operation time, perioperative-postoperative complications, perioperative complications, and stone-free rates of patients who underwent fRIRS for ureteral or renal calculi were evaluated. Claven-Dindo classification was used for complications. All procedures were performed under spinal or general anesthesia.

RESULTS

1079 patients were included in the study. Of the 1079 patients, 352 (32.6%) were female and 727 (67.4%) were male. The mean age was 47.33 ± 14.31 years. The mean size of the stones was 13.1 ± 6.33 mm3. Of the patients, 208 (19.27%) received general anesthesia and 871 (80.73%) received spinal anesthesia. The mean operation time was 37.14 ± 17.65 min. All patients received a Double J (DJ) stent postoperatively. The rate of complications was 8% overall. The complications observed in general were minor; postoperative colic pain and hematuria were observed in 36 (3.3%) patients and 26 (2.4%) patients, respectively. Stone-free rate was 86.4%.

CONCLUSION

The fRIRS is a safe and feasible method for the treatment of uncomplicated ureteral and renal calculi. In uncomplicated patients, it has similar complication and success rates to conventional methods and eliminates radiation exposure.

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.

Comparison of flexible and navigable suction ureteral access sheath with conventional ureteral access sheath for pediatric retrograde intrarenal surgery: a single-center propensity-matched analysis

The flexible and navigable suction ureteral access sheath (FANS-UAS) has increasingly been recognized as a potential game changer for retrograde intrarenal surgery (RIRS). While this innovative technology has demonstrated promising results in adult populations, there is a notable lack of evidence regarding its application in pediatric cases, particularly in comparison to conventional ureteral access sheaths (CUAS). This study aimed to perform a comparative analysis of pediatric kidney stone cases treated with RIRS using FANS-UAS and CUAS. We conducted a retrospective matched pair analysis, matching patients based on preoperative age, stone location, and stone size. After matching, data from 46 patients (23 in each group) were analyzed. The groups were comparable in terms of age, hydronephrosis degree, location and size of the stone (p = 0.543, p = 0.807, p = 0.840, and p = 0.577, respectively). Operation times were shorter in the FANS-UAS group (CUAS: 67.9 ± 21.0 min, FANS-UAS: 50.4 ± 21.1 min, p = 0.007). The initial stone-free rate (SFR) was 65.2% in the CUAS group and 91.3% in the FANS-UAS group, with a statistically significant difference (p = 0.032). However, no significant difference was found regarding the final SFR (p = 0.295). The number and duration of DJ-stents, were significantly higher in the CUAS group (p = 0.006 for both). The FANS-UAS group had a significantly fewer anesthesia sessions (p = 0.001). There were no significant differences in complication rates (p = 0.303). Our findings suggest that FANS-UAS offers significant advantages over CUAS in pediatric RIRS, including higher initial success rates, shorter operation times, reduced anesthesia requirements, and fewer treatment sessions, with comparable safety profiles.

Comparison of two negative pressure ureteral access sheaths combined with day-case flexible ureteroscopy for renal stones randomized trial

To compare the safety and effectiveness of the combination of intelligent intrarenal pressure control platforms and flexible end ureteral access sheath combined with flexible ureteroscopic lithotripsy (FURL) for the treatment of renal stones less than 2 cm with day case mode. From November 2023 to July 2024, a prospective, randomized, double-blind, parallel-controlled study was conducted to recruit 60 patients with upper urinary tract calculi measuring ≤ 2 cm in longest diameter. A total of 60 eligible patients were consecutively enrolled. Based on a pre-generated random number table and allocation scheme using SPSS 27.0, patients were assigned to either the intelligent pressure control group (IFURL, n = 30) or the head bending group (BFURL, n = 30). Blinding measures were implemented for patients, data collectors, statisticians, and analysts, with the allocation results disclosed to the surgeons prior to the start of the procedure in the operating room. The operation duration for IFURL and BFURL was 52.50 (48.00, 60.00) vs. 46.00 (36.00, 56.25), respectively (p = 0.047). Stone free rate (SFR) on the first postoperative day was 73.33% vs. 93.33% for IFURL and BFURL, respectively (p = 0.038). While, SFR was no significant difference between the two groups after two months(90.00% vs. 96.67%, p = 0.301). One patient in IFURL was readmitted after discharge due to fever 2 days post-discharge, and improved after 2 days of anti-infection treatment. One patient in BFURL was readmitted due to lumbar and abdominal pain from urine extravasation, which improved after 3 days of anti-infection treatment. SFR of one-month post-surgery for renal calculi ≤ 2 cm treated with intelligent pressure control and flexible UAS combined with FURL in day surgery mode was similar, with low infection-related complications and rehospitalization rates, showing no statistical difference. However, the overall hospitalization costs for the BFURL was lower than IFURL.

Microchannel percutaneous nephrolithotomy versus flexible ureteroscopic lithotripsy for the treatment of 1-2 cm high hardness single upper ureteral stones: a propensity score-matched study

The objective of this study was to compare the clinical efficacy and safety of microchannel percutaneous nephrolithotripsy (MPCNL) with flexible ureteroscopic lithotripsy (FURL) in the treatment of single upper ureteral stones with a diameter of 1-2 cm and high hardness. This study retrospectively analyzed 89 patients diagnosed with a single upper ureteral stone with a 1-2 cm diameter and a computed tomography value > 1000 Hounsfield units. A propensity score matching system matched this study with factors to minimize the effect of baseline differences between patients. Ultimately, 29 patients in each of the two groups were successfully matched. The stone-free rate was marginally higher in the MPCNL group than in the FURL group (93.10% vs. 86.21%), although the difference did not reach statistical significance (P = 0.666). Furthermore, the mean operative time in the MPCNL group, although slightly longer than that in the FURL group, did not demonstrate a statistically significant difference (P = 0.833). However, patients in the MPCNL group exhibited a significantly more substantial decrease in hemoglobin than those in the FURL group (P < 0.001) and a substantially more extended postoperative hospital stay (P < 0.001). Regarding perioperative complications, the incidence of moderate pain was higher in the MPCNL group than in the FURL group (P = 0.037). The difference in overall complication rates between the two groups did not reach statistical significance (P = 0.108). MPCNL and FURL are efficacious surgical procedures for treating single upper ureteral stones with a 1-2 cm diameter and high hardness.

Intelligent control of pressure based on ureteral access sheaths: renal pelvic pressure during flexible ureteroscope perfusion at different sites

OBJECTIVE

This study aimed to evaluate the accuracy and effectiveness of renal pelvic pressure (RPP) control during flexible ureteroscopic perfusion at various sites.

METHODS

Flexible ureteroscopy for the intelligent control of RPP was based on a ureteral access sheath (UAS) that integrated pressure measurement and suction functions (with automatic adjustment). Eleven consecutive patients with indurating nephrostomy tubes were enrolled. The nephrostomy tube was connected to a disposable invasive blood pressure sensor. The RPP was zeroed after the pressure stabilized. The flow rate and control value were set at 100 ml/min and - 5 mmHg, respectively. An 8.5 Fr flexible ureteroscope was irrigated at the renal pelvis, as well as the upper, middle, and lower calyces of the kidney for 1 min.

RESULTS

All 11 patients with upper urinary tract calculi underwent successful UAS placement. Pressures measured by the sheath and fistula during perfusion were - 5.07 ± 1.41 and - 4.89 ± 1.07 mmHg at the renal pelvis, -5.16 ± 1.36 and - 5.12 ± 1.32 mmHg at the upper calyces, -4.98 ± 0.87 and - 5.39 ± 1.01 mmHg at the middle calyces, as well as -4.95 ± 1.56 and - 5.64 ± 1.24 mmHg at the lower calyces, respectively. There were no significant differences in pressure between the sheath and fistula groups or in sheath and fistula pressures among parts. The RPP fluctuated; however, all values were within the safe limit of 20 mmHg.

CONCLUSION

The UAS-based pressure monitoring technology can accurately and reliably monitor and control RPP within a set range.

Does tilt-retrograde intrarenal surgery enhance stone clearance and offer better surgical ergonomics in patients with renal calculi? A prospective randomized control study

Introduction

Retrograde intrarenal surgery (RIRS) is the standard treatment for renal calculi. Direct visualization and fragmentation are its major advantages. The variable stone clearance rates and the ergonomic challenges faced by urologists are a few limitations. Table tilt enhances stone clearance and improves surgical ergonomics by facilitating better access to stones and reducing procedural strain.

Subjects and Methods

In this prospective study, patients with intrarenal calculi were randomized into standard lithotomy RIRS (S-RIRS) and table-tilted RIRS (T-RIRS) groups. Specified table tilts were suggested for each of the stone locations. The outcomes with regard to stone clearance, operative and lasing time, and ergonomics were studied.

Results

About 100 patients were studied, with 50 in each group. The overall operating time and lasing time in the T-RIRS group were less than that in the S-RIRS group (P < 0.001). The complication rates were the same in both groups. Most surgeons felt that the surgical ergonomics was better in the T-RIRS group (P < 0.001). When stone-free status was analyzed, seven patients in the S-RIRS group and one in the T-RIRS group had residual stones. The mean Borg category-ratio 10 (CR-10) scores in the S-RIRS and T-RIRS groups were 4.18 and 2.20, respectively (P < 0.001).

Conclusions

This is the first study to document the distinct advantages of T-RIRS and its benefits on surgical ergonomics. T-RIRS resulted in significantly shorter operative and lasing times, particularly for stones in lower calyces. Surgical ergonomics, assessed by the Borg CR-10 scale, were significantly better in the T-RIRS group. T-RIRS should become a standard of care for patients undergoing RIRS.

Lower Pole Stones Are Associated with Low Stone-Free Rates in Retrograde Intrarenal Surgery: A Myth or Fact? - A Matched Case-Control Study from the RIRSearch Group

INTRODUCTION

There are conflicting results in the literature regarding the efficacy of retrograde intrarenal surgery (RIRS) in lower pole stones. This study aimed to evaluate RIRS outcomes in lower pole stones by forming matched case-control groups.

METHODS

The data of 491 patients who were diagnosed with kidney stones and underwent RIRS were retrospectively included in the study. A total of 209 patients with lower pole stones (Group 1) and 282 patients with pelvic stones (Group 2) were matched at a 1:1 ratio in terms of stone burden, stone density, preoperative double-J stenting status, and a previous history of shock wave lithotripsy, yielding 159 patients in each group. A computed tomography scan was performed to evaluate the stone-free status. The primary outcome was stone-free status 1 month after RIRS.

RESULTS

After case-control matching, the median age was 49 years (interquartile range [IQR]: 40-58) in Group 1 and 50 years (IQR: 35-60) in Group 2 (p = 0.388). The median stone burden values of Group 1 and Group 2 were 415.3 mm3 (IQR: 176.1-858.2) and 503.3 mm3 (IQR: 282.5-864), respectively (p = 0.100). After RIRS, stone-free status was achieved by 126 of the 159 (79.2%) in Group 1 and 133 of the 159 (83.6%) patients in Group 2 (p = 0.387). The groups were similar in terms of perioperative complications (4.4% in Group 1 and 3.8% in Group 2, p = 0.777), postoperative complications (13.8% in Group 1 and 10.3% in Group 2, p = 0.393), and median operation time (60 min in both, p = 0.230). A longer median fluoroscopy time was noted in Group 1 compared to Group 2 (26 s and 3 s, respectively, p = 0.013).

CONCLUSIONS

Stone-free rates and complications were comparable between the patients with lower pole and pelvic stones after RIRS. However, lower pole stones are associated with longer fluoroscopy time. RIRS can be performed effectively for the treatment of lower pole stones.

Fluid absorption during flexible ureteroscopy with intelligent control of renal pelvic pressure: a randomized controlled trial

PURPOSE

To investigate fluid absorption and its influencing factors during flexible ureteroscopy with intelligent control of renal pelvic pressure (RPP).

METHODS

A total of 80 patients with upper urinary tract calculi underwent flexible ureteroscopy with intelligent control of RPP by pressure-measuring ureteral access sheath and were randomly divided into four groups. The RPP of Groups A, B, and C were set at - 5, 0 and 5 mmHg, respectively. Conventional flexible ureteroscopy with uncontrolled pressure served as control Group D. The perfusion flow rate was set at 100 ml/min in the four groups, with 20 patients in each group. The fluid absorption was measured by 1% ethanol every 10 min. Operation time, stone-free rate, and complications were recorded.

RESULT

Seventy-three patients were finally included in the RCT. The general and preoperative data of the patients were comparable between the groups. The fluid absorption of Groups A, B, and C was significantly less than that of Group D (P < 0.01). Fluid absorption and operation time were positively correlated, and the correlation coefficients R were 0.864, 0.896, 0.918, and 0.947, respectively (P < 0.01). The fluid absorption of patients with vomiting, fever and ureteral injury was greater than that of patients without complications in the four groups (P < 0.01). In different groups, fluid absorption was greater in patients with ureteral injury Post-Ureteroscopic Lesion Scale (PULS) 1-3 than in noninjured patients (P < 0.01).

CONCLUSION

Flexible ureteroscopy with intelligent control of RPP effectively reduces the absorption of perfusion fluid. Operation time and ureteral injury are also key factors affecting perfusion fluid absorption.

REGISTRATION NUMBER AND DATE

NCT05201599; August 11, 2021.

The Utility and Safety of Ureteral Access Sheath During Retrograde Intrarenal Surgery in Children

OBJECTIVE

To compare retrograde intrarenal surgery (RIRS) with and without ureteral access sheath (UAS) in different pediatric age groups.

METHODS

The data of RIRS for kidney stone in children were obtained from 9 institutions. Demographic characteristics of patients and stones, intraoperative and postoperative results were recorded. While analyzing the data, patients who underwent RIRS without UAS (group 1) (n = 195) and RIRS with UAS (group 2) (n = 194) were compared.

RESULTS

Group 1 was found to be young, thin, and short (P <.001, P = .021, P <.001), but there was no gender difference and similar symptoms were present except hematuria, which was predominant in group 2 (10.6% vs 17.3%, P <.001). Group 1 had smaller stone diameter (9.91 ± 4.46 vs 11.59 ± 4.85 mm, P = .001), shorter operation time (P = .040), less stenting (35.7% vs 72.7%, P = .003). Re-intervention rates and stone-free rates (SFR) were similar between groups (P = .5 and P = .374). However, group 1 had significantly high re-RIRS (P = .009). SFR had a positive correlation with smaller stone size and thulium fiber laser usage compared to holmium fiber laser (HFL) (P <.001 and P = .020), but multivariate analysis revealed only large stone size as a risk factor for residual fragments (P = .001).

CONCLUSION

RIRS can be performed safely in children with and without UAS. In children of smaller size or younger age (<5 years), limited use of UAS was observed. UAS may be of greater utility in stones larger than 1 cm, regardless of the age, and using smaller diameter UAS and ureteroscopes can decrease the complications.

Ureteroscopy for urolithiasis in bedridden patients: it is feasible and acceptable

PURPOSE

To investigate the safety of transurethral ureteroscopy (URS) for urolithiasis in bedridden patients and to identify bedridden patient-specific risk factors for postoperative complications.

METHODS

The patients who underwent URS for urolithiasis were divided into bedridden patients and good performance status (PS) patients, and the groups were compared regarding their clinical characteristics and postoperative complications. A multivariable logistic regression analysis was performed to evaluate independent predictors of postoperative febrile urinary tract infection (fUTI).

RESULTS

A total of 1626 patients were included, 276 in the bedridden patient group, and 1350 in the good PS patient group. The bedridden patient group had a significantly higher age and higher proportion of females and had multiple comorbidities. In 77 patients (27.9%), 88 postoperative complications developed for the bedridden patient group. Clavien-Dindo grade III or IV complications were observed in only 8 patients. No grade V complications were observed. The most common complication was fUTI. The frequency of fUTI with grade III or IV for the bedridden patient group (2.2%) was higher compared with the good PS patient group (0.5%), but the difference was not statistically significant (p = 0.13). Bedridden patient-specific risk factors for fUTI included female sex, diabetes mellitus, cerebrovascular comorbidities, lower extremity contracture, and prolonged operative time.

CONCLUSION

URS for urolithiasis is a feasible and acceptable procedure in bedridden patients, despite the moderate rate of postoperative complications. The identified risk factors provide a framework for risk stratification and individualized care in this unique patient population.

Analyzing global research trends and focal points in the utilization of laser techniques for the treatment of urolithiasis from 1978 to 2022: visualization and bibliometric analysis

Laser lithotripsy is gaining global prominence and is a dynamically progressing field marked by a continual influx of new and comprehensive research each year. Recently, there has been a noticeable shift toward the adoption of various kinds of lasers, such as holmium: yttrium-aluminum-garnet (Ho:YAG) and thulium fiber (TFL) lasers. Consequently, we aim to conduct a bibliometric analysis to analyze key areas of research activity within scientific publications that center on the utilization of laser techniques in urolithiasis. A search of the literature spanning from 1978 to 2022 was carried out on 25 December 2023 using the Scopus database to explore research related to the application of laser techniques for urolithiasis treatment. Visualization analysis was performed using VOSviewer software (version 1.6.20). We examined 962 publications that met the specified criteria, 791 (82.22%) of which were original articles. The analysis of the retrieved publications indicated a consistent increase in research output from 1978 to 2022; a particularly noteworthy surge occurred after 2003. In particular, the U.S. claimed the leading position as the most productive country, contributing 211 articles (21.93%). However, India had the highest research productivity according to the adjustment index of 19.08. In the European region, 324 publications (33.68% of the total) originated from 25 countries. The Journal of Endourology contributed the most between 1978 and 2022 (n = 96, 9.98%). The most cited paper examined the effectiveness of holmium: yttrium-aluminum-garnet (Ho:YAG) lasers, while a subsequent study focused on the use of a thulium fiber laser (TFL), an emerging laser technology that has gained increased recognition. Co-occurrence analysis revealed three distinct clusters focusing on the types of laser technology, minimally invasive approaches, and success rate/postoperative complications. This comprehensive investigation delves into the global landscape of laser use for the treatment of urolithiasis. This review supports the emerging clinical concept of using various types of laser technology for urolithiasis treatment. Moreover, the hot issues that researchers should focus on based on the findings of this study are the use of different types of laser lithotripsy in view of the surgical approach, success rate and complications.

Prospective Evaluation of Risk Factors Responsible for Infection Following Retrograde Intrarenal Surgery

OBJECTIVE

The study aimed to identify the various risk factors for infective complications following retrograde intrarenal surgery (RIRS).

MATERIALS AND METHODS

The study was conducted over one year, and the incidence of infectious complications after RIRS was calculated. Patients were divided into two groups based on the presence and absence of infective complications and were compared in terms of preoperative and operative characteristics. The complications were assessed and graded according to the Modified Clavien classification system (MCCS). The Fisher's exact test, Student's t-test, and Mann-Whitney U test were used for univariate analysis. Multivariate logistic regression analysis was used to identify independent risk factors for postoperative urinary tract infection (UTI).

RESULTS

Out of 165 patients in the study, 27 (16.7%) patients developed UTI within one month of undergoing RIRS. The most frequent complication was fever, which occurred in 13 (7.8%) patients. When stratified by MCCS, 13 were grade I, nine were grade II, four were grade III, and one was a grade IV complication. High stone burden, concomitant diabetes mellitus, and multiple renal stones were identified as substantial risk factors for postoperative UTI in univariate analysis. On multivariate analysis, preoperative UTI and prolonged operative time were found to have a significant association with postoperative UTI.

CONCLUSION

The present study demonstrated that preoperative UTI and prolonged operative time are independent factors responsible for postoperative UTI. Large stone burden, stone multiplicity, and diabetes mellitus contribute to a higher risk for UTI following RIRS.

Retrograde intrarenal surgery with central neuraxial blockade versus general anesthesia: A systematic review and meta-analysis

Objective

The aim of the article is to assess the impact of retrograde intrarenal surgery under central neuraxial blockade in comparison to general anesthesia (GA).

Material and Methodology

This systematic review was conducted following the guidelines set out by the preferred reporting items for systematic reviews and meta-analyses. We conducted a comprehensive search across major electronic databases, including various types of studies such as descriptive studies and full-text literature, all of which were incorporated into the current review from 2018 to 2023. We involved those studies, which included the comparative study of spinal anesthesia (SA), epidural anesthesia (EA), and combined spinal epidural anesthesia with GA.

Result

In our meta-analysis of 12 studies, it was found that anesthesia technique significantly affected operation time, with neuraxial anesthesia (NA) showing a mean difference of -2.28 (95% confidence interval (CI): -3.5 to -1.04, P = 0.003) compared to GA. However, there were no significant differences in rates of stone clearance, 24-h pain scores and length of hospital stay among patients administered with NA or GA for retrograde intrarenal surgery (RIRS).

Conclusion

On the basis of the outcomes of study, NA can serve as a viable alternative to GA for RIRS. Our analysis reveals no significant differences in rates of stone clearance, operation duration, 24-h pain scores, complication rates, and length of hospital stay between NA in addition to GA in the context of RIRS. This suggests that given the potential economic advantages, NA might be a preferable choice over GA, contingent on patient preferences, baseline characteristics, and stone burden.

Vacuum-assisted dedusting lithotripsy in the treatment of kidney and proximal ureteral stones less than 3 cm in size

PURPOSE

This study aimed to compare the outcomes of vacuum-assisted dedusting lithotripsy (VADL) using flexible vacuum-assisted ureteral access sheath (FV-UAS) versus traditional flexible ureteroscopic lithotripsy (fURL) in patients with kidney or proximal ureteral calculi less than 3 cm in size.

METHODS

A total of 371 patients who successfully underwent fURL treatment were enrolled. These patients were divided into traditional fURL group and VADL group. Outcomes of both groups were compared using 1:1 propensity score-matched analysis. Stratified analyses based on stone size and location were also conducted.

RESULTS

Finally, 103 well-matched patients in each group were identified. No septic shock or death occurred. The immediate stone-free rate (SFR) and follow-up SFR of VADL group were significantly higher (78.6% vs. 50.5%, p < 0.001; 94.2%% vs. 75.7%, p < 0.001). No difference was observed in postoperative fever rate (2.9% vs. 3.9%, p = 1.000) and duration of lithotripsy (37.7 ± 20.1 min vs. 40.3 ± 18.9 min, p = 0.235). For patients with stones ≤ 2 cm in size, the immediate SFR and follow-up SFR in VADL group were higher (86.7% vs. 60.6%, p < 0.001; 96.0% vs. 83.1%, p = 0.010). The same trend was observed in the 2-3 cm subgroup (57.1% vs. 28.1%, p = 0.023; 89.3% vs. 59.4%, p = 0.009). Although the in situ fragmentation strategy was employed more frequently in VADL group for lower pole stones, the SFR was still higher. Subgroup analyses did not reveal any significant differences in either infectious complications or duration of lithotripsy.

CONCLUSION

VADL technique can significantly improve the postoperative SFR for the patients with kidney or proximal ureteral stones less than 3 cm in size treated by flexible ureteroscope.

Is It a Good Strategy to Proceed a Retrograde Intrarenal Surgery Session Sheathless After Ureteral Access Sheath Insertion Failure? A RIRSearch Study

Objectives: To complement our previous findings regarding effect of ureteral access sheath (UAS) use, we checked RIRSearch database for patients who operated without using UAS. The aim of the study was to understand these new data better by comparing outcomes of retrograde intrarenal surgery (RIRS) that continued sheathless after a failed UAS insertion vs those planned and completed sheathless. Materials and Methods: Data of 195 patients who underwent sheathless RIRS for kidney and/or ureteral stones between 2011 and 2021 were retrieved from the database. Patients divided into two groups: cases who were planned and completed sheathless (n = 110, Group 1) and those who proceeded without UAS after insertion failure (n = 85, Group 2). After propensity score matching (PSM), each group consisted of 76 patients. Results: After PSM, stone-free rate for Group 1 (90.8%) was significantly higher than stone-free rate of Group 2 (76.3%) in sheathless RIRS (p = 0.02). Also postoperative complication rate was significantly lower in Group 1 (10.5%) than in Group 2 (27.6%) (p = 0.007). In Group 2, median operating time was longer (60 minutes, interquartile range [IQR]: 40-80) and more unplanned auxilliary procedure (22.4%) was needed than Group 1 (45 minutes, IQR: 40-50 and 3.9%) (both p = 0.001). Stone burden (odds ratio [OR]: 1.002, p = 0.019) and stone density (OR: 1.002, p = 0.003) were associated with high risk of residual stones after RIRS. Higher hydronephrosis grades were associated with increased stone-free rates (OR: 0.588 for residual stone risk, p = 0.024). Cases who completed sheathless by dusting all available stones, as planned preoperatively, were more likely to have stone-free status after RIRS than those who proceeded sheathless after UAS insertion failure (OR: 2.645, p = 0.024). Conclusions: Operation course after UAS insertion failure may be more challenging. In cases who performed without using UAS, surgeons who proceed with procedure sheathless after UAS insertion failure may more frequently run into complications and may fail achieving stone-free status compared with sheathless-planned cases.

Safety and efficacy of ureteroscopy for urolithiasis in octogenarians

OBJECTIVE

To examine the safety and efficacy of ureteroscopy (URS) for urolithiasis in octogenarians, and identify preoperative risk factors for the incidence of postoperative complications.

METHODS

The patients who underwent URS for urolithiasis were divided into octogenarians and younger patients (age: <80 years), and the groups were compared regarding their clinical characteristics, intraoperative and postoperative complications, and stone-free rate. The predictors of postoperative complications were evaluated using logistic regression models.

RESULTS

A total of 1207 patients were included, 166 in the octogenarian patient group and 1041 in the younger patient group. The proportion of female patients (p < 0.001), American Society of Anesthesiologists (ASA) score (p < 0.001), rate of preoperative pyelonephritis (p < 0.001), and diabetes mellitus (p = 0.003) were higher in the octogenarian group. No statistically significant differences were found between the two groups regarding stone size, location, and intraoperative complications. Postoperative complications, which reached a significant difference, were observed in 34 (20.5%) octogenarians and 117 (11.2%) younger patients (p = 0.002). However, age itself was not significantly associated with postoperative fever, the most frequent postoperative complication, in multivariate analysis. Female sex, ASA score of ≥3, history of diabetes mellitus, and prolonged operative time (≥120 min) were the significant predictors of fever. The stone-free rate in the octogenarian group was superior to that in the younger patient group (80.1% vs. 70.6%, respectively; p = 0.035).

CONCLUSION

Our results suggest that URS for urolithiasis can be safely and effectively applied to octogenarians in selected cases.

International Alliance of Urolithiasis guideline on retrograde intrarenal surgery

OBJECTIVES

To set out the second in a series of guidelines on the treatment of urolithiasis by the International Alliance of Urolithiasis that concerns retrograde intrarenal surgery (RIRS), with the aim of providing a clinical framework for urologists performing RIRS.

MATERIALS AND METHODS

After a comprehensive search of RIRS-related literature published between 1 January 1964 and 1 October 2021 from the PubMed database, systematic review and assessment were performed to inform a series of recommendations, which were graded using modified GRADE methodology. Additionally, quality of evidence was classified using a modification of the Oxford Centre for Evidence-Based Medicine Levels of Evidence system. Finally, related comments were provided.

RESULTS

A total of 36 recommendations were developed and graded that covered the following topics: indications and contraindications; preoperative imaging; preoperative ureteric stenting; preoperative medications; peri-operative antibiotics; management of antithrombotic therapy; anaesthesia; patient positioning; equipment; lithotripsy; exit strategy; and complications.

CONCLUSION

The series of recommendations regarding RIRS, along with the related commentary and supporting documentation, offered here should help provide safe and effective performance of RIRS.

Risk of Sepsis in Retrograde Intrarenal Surgery: A Systematic Review of the Literature

Context

Objective

Evidence acquisition

Evidence synthesis

Conclusions

Patient summary

Spinal versus general anesthesia in retrograde intrarenal surgery

AIM

The indications for retrograde intrarenal 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 outcomes of RIRS performed under SA versus general GA for renal stones.

MATERIALS AND METHODS

This was a retrospective, observational study in patients scheduled for RIRS in a single teaching hospital in Turkey. 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. Results were evaluated in terms of surgical outcome, intraoperative and postoperative complications. Patients were followed-up until day 90 from discharge.

RESULTS

The data of 502 patients, 252 in GA group and 250 in SA group, were evaluated. The stone-free rate was 81% in the GA group and 85% in the SA group (p = 0.12). No cases of conversion from SA to GA were recorded. Complication rates were similar in the 2 groups (19% vs 14.5%, p = 0.15).

CONCLUSIONS

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

Evaluation of the optimal duration for retrograde intrarenal stone surgery to prevent postoperative complications

OBJECTIVE

To evaluate retrograde intrarenal surgery (RIRS) outcomes and to determine the effect of operative time on complications of RIRS.

METHODS

Patients undergoing RIRS for renal stones were evaluated. These patients were divided into two groups according to the operation time (Group 1<60 minutes and Group 2>60 minutes). Peroperative outcomes such as fluoroscopy time, stone-free rates, complications and duration of hospitalization were compared.

RESULTS

Group 1 consisted of 264 patients and Group 2 consisted of 297 patients. SFR rates, duration of hospitalization, and postoperative urinary tract infection rates were similar in both groups. Fluoroscopy time was 7.8±7.3 (0-49) sec in group 1 and 13.1±9.8 (0-81) sec in group 2. Complications according to modified Clavien-Dindo classification system (MCDCS) were 13 and 32 patients (Grade 1), 31 and 63 patients (Grade 2), 1 and 1 patient (Grade 3) in group 1 and 2, respectively. There was statistical difference between the two groups in terms of duration of fluoroscopy time and the MCDCS. Although duration of hospitalization and UTI rates were higher in group 2, no statistical significance was observed among groups.

CONCLUSION

Limiting the operation time to 60 minutes in RIRS seems to be important in reducing postoperative complications.

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 611 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.

Suctioning Flexible Ureteroscopy with Automatic Control of Renal Pelvic Pressure versus Mini PCNL for the Treatment of 2-3-cm Kidney Stones in Patients with a Solitary Kidney

OBJECTIVE

The aim of the study was to compare the treatment outcomes between suctioning flexible ureteroscopic lithotomy (SF-URL) with automatic control of renal pelvic pressure and minimally invasive percutaneous nephrolithotomy (MPCNL) for the management of 2-3-cm renal stones in patients with a solitary kidney.

MATERIALS AND METHODS

A total of 127 patients with a solitary kidney who underwent SF-URL (n = 57) or MPCNL (n = 70) for large renal stones (>2 cm) between June 2015 and October 2020 were consecutively analyzed. The stone characteristics, operative times, stone-free rate (SFR), hospital stays, and incidences of complications were compared.

RESULTS

There was a significantly shorter operative time with MPCNL than with SF-URL (43.4 ± 18.9 min vs. 61.8 ± 21.1 min, p = 0.012). SFR at 30 days were 80.7% (46/57) and 90.0% (63/70) for SF-URL and MPCNL, respectively (p > 0.05). The SFR at the 3-month follow-up was comparable in both groups (91.2% vs. 95.7%, p > 0.05). The hemoglobin decline value, hospital stay, serum cystatin C, and percentage of patients requiring blood transfusions in the SF-URL group were obviously better than those in the MPCNL group: (0.8 ± 0.4) versus (3.9 ± 2.7) g/dL (p = 0.007), (3.6 ± 1.5) versus (6.9 ± 3.1) days (p = 0.013), (1.02 ± 0.48) versus (2.54 ± 0.69) mg/L (p = 0.011), and 0 (0.0%) versus 7 (10.0%) (p = 0.016), respectively. The percentages of patients with thrombosis and perirenal hematoma in the MPCNL group were higher than those in the SF-URL group, but the difference was not statistically significant (p > 0.05).

CONCLUSION

For the treatment of 2-3-cm renal stones in patients with a solitary kidney, both SF-URL and MPCNL are effective. MPCNL has the advantage of a shorter operation time. However, SF-URL is characterized by less bleeding, shorter hospital stay, and less damage to kidney function.

Super-mini percutaneous nephrolithotomy (SMP) vs retrograde intrarenal surgery (RIRS) in the management of renal calculi ≤ 2 cm: a propensity matched study

OBJECTIVE

To compare the effectiveness and safety of Super-Mini PCNL (SMP) and Retrograde Intrarenal Surgery (RIRS) in the management of renal calculi ≤ 2 cm.

PATIENTS AND METHODS

A prospective, inter-institutional, observational study of patients presenting with renal calculi ≤ 2 cm. Patients underwent either SMP (Group 1) or RIRS (Group 2) and were performed by 2 experienced high-volume surgeons.

RESULTS

Between September 2018 and April 2019, 593 patients underwent PCNL and 239 patients had RIRS in two tertiary centers. Among them, 149 patients were included for the final analysis after propensity-score matching out of which 75 patients underwent SMP in one center and 74 patients underwent RIRS in the other. The stone-free rate (SFR) was statistically significantly higher in Group 1 on POD-1 (98.66% vs. 89.19%; p = 0.015), and was still higher in Group 1 on POD-30 (98.66% vs. 93.24%, p = 0.092) SFR on both POD-1 and POD-30 for lower pole calculi was higher in Group 1 (100 vs. 82.61%, p = 0.047 and 100 vs 92.61% p = 0.171). The mean (SD) operative time was significantly shorter in Group 1 at 36.43 min (14.07) vs 51.15 (17.95) mins (p < 0.0001). The mean hemoglobin drop was significantly less in Group 1 (0.31 vs 0.53 gm%; p = 0.020). There were more Clavien-Dindo complications in Group 2 (p = 0.021). The mean VAS pain score was significantly less in Group 2 at 6 and 12 h postoperatively (2.52 vs 3.67, 1.85 vs 2.40, respectively: p < 0.0001), whereas the mean VAS pain score was significantly less in Group 1 at 24 h postoperatively (0.31 vs 1.01, p < 0.0001). The mean hospital stay was significantly shorter in Group 1 (28.37 vs 45.70 h; p < 0.0001).

CONCLUSION

SMP has significantly lower operative times, complication rates, shorter hospital stay, with higher stone-free rates compared to RIRS. SMP is associated with more early post-operative pain though.

Retrograde intrarenal surgery is a safe procedure in severe obese patients. Is it reality or prediction? A propensity score-matching analysis from RIRSearch study group

OBJECTIVE

The aim of the study was to assess whether severely obese patients have an increased risk of complications during and after retrograde intrarenal surgery.

MATERIALS AND METHODS

The data of 639 consecutive patients undergoing retrograde intrarenal surgery for the treatment of upper tract urinary stones were analyzed retrospectively. The patients were divided into two groups according to their body mass index numbers (Group 1, <35; Group 2, ≥35). The patients' demographics, stone characteristics, operative outcomes, and complication rates were compared between the groups. The primary objective was to examine whether the intraoperative and postoperative complication rates were higher in patients with a body mass index of ≥35 kg/m2.

RESULTS

After matching of confounding factors, Group 1 comprised 135 patients, and Group 2 comprised 47 patients. The baseline characteristics were similar between the groups. There were no significant differences between groups for intraoperative complication rates (11.8% and 12.8%, respectively; p=0.97). There was statistically significant difference in favor of Group 2 for postoperative complication rates (12.6% and 29.7%; respectively, p<0.01), overall complication rates (22.9% and 38.2%; respectively, p=0.02), mean operation time (56.15 minute vs 66.45 minute; respectively, p= 0.01) and length of stay (1.4 days vs 2.1 days; p=0.03). Stone free rates (75.5% vs 85.1%; respectively, p=0.17) did not differ between groups.

CONCLUSIONS

Retrograde intrarenal surgery is an efficient and feasible treatment option for upper urinary tract stones in severe obese patients. However, higher possibility of postoperative, especially infectious, complication rates should be taken into account in these patients.

Retrograde intrarenal surgery for the treatment of renal stones in patients with a solitary kidney: Does access sheath matter?

Background

Treating renal stones in patients with a solitary functioning kidney is challenging. The present study was aimed to assess the competence and safety of retrograde intrarenal surgery (RIRS) for the treatment of renal stones in a solitary kidney.

Methods

Between August of 2017 and August of 2019, 25 ensuing patients with a solitary kidney and renal calculi and who were treated with RIRS were prospectively enlisted in the study. All patients were assessed by non-contrast computed tomography before surgery. Stone-free status was determined if there were no residual fragments. The final stone-free rates (SFRs) were assessed 3 months after the last treatment session by plain X-ray KUB and ultrasonography. Patient demographics, perioperative and postoperative outcomes were prospectively evaluated. Serum creatinine levels and glomerular filtration rate (GFR) pre-procedure and during follow-up were correlated.

Results

Twenty-five patients underwent 26 procedures. The mean patient age was 42.81 ± 12.3 (range 22–67) years. The mean stone size was 18.23 ± 6.27 mm (range 9–25 mm) and the mean operative time was 46.15 ± 15.34 min (range 25–100 min). A ureteral access sheath (UAS) was used in five (19.2%) pre-stented patients. One patient (3.8%) required the second stage RIRS for residual stones. The SFR after the initial and final procedures, the SFR was 84% and 92%, respectively.

The mean serum creatinine levels were significantly reduced post-surgery compared to preoperative levels (1.76 ± 1.21 mg/dL; 1.37 ± 0.60 mg/dL; p value 0.001) while GFR not encounter any significant variation post-surgery (63.04 ± 33.16 ml/min) compared to preoperative rates (61.12 ± 34.76 ml/min, p value 0.502). Minor complications classified as Clavien I or II developed in 5 patients (20%). Clavien IIIb, a major complication, developed in one (4%) patient, which was caused by steinstrasse and necessitated emergency surgical intervention.

Conclusion

Renal stones in a solitary kidney can be managed using RIRS safely and effectively with and without the use of UAS, without compromising renal function.

Risk factors for infectious complications after retrograde intrarenal surgery - a systematic review and narrative synthesis

Introduction

Infectious complications are among the most frequent and significant complications in retrograde intrarenal lithotripsy. To date, review articles have covered complications after a ureteroscopy, but not after retrograde intrarenal surgery (RIRS), specifically. Because the complications and risk factors are different for a ureteroscopy and RIRS, we aimed to identify variables related to the occurrence of infectious complications post-RIRS.

Material and methods

This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. We included original studies that described 100 or more procedures published in 2014–2021. We extracted data and performed a narrative synthesis to explore and interpret differences between the studies.

Results

We selected 17 studies for analysis, including 10 from 2019–2021. Infectious complications after RIRS were observed in 2.8–7.5% of patients (mean 7.1%). We found seven independent risk factors associated with infectious complications after RIRS: long operative time, recent history of positive urine culture or urinary tract infection or antibiotic use, pyuria/nitrites, small caliber of ureteral access sheath, struvite stone, high irrigation rate, and comorbidities.

Conclusions

If an increased rate of infectious complications is found at a RIRS center, countermeasures should include restrictions on operative time and irrigation rate, and consideration of larger access sheaths, especially for patients with abnormal urine results or with struvite stones or with a history of urinary tract infection or co-morbidities.

Retrospective analysis of the factors affecting intraoperative and immediate postoperative complications of RIRS classified by the Clavien and Satava grading systems

BACKGROUND

To classify intraoperative and postoperative complications using the modified Clavien classification system(MCCS) and modified Satava classification system(SCS) and to evaluate the parameters associated with complications in patients undergoing retrograde intrarenal surgery(RIRS) for renal and proximal ureteral stones.

MATERIALS AND METHODS

We performed a retrospective analysis of 949 patients who underwent RIRS for renal stones and proximal ureteral stones at two institutions between March 2015 and June 2020. Intraoperative complications were assessed using SCS and postoperative complications were graded according to MCCS. Univariate and multivariate analyses were undertaken to determine predictive factors affecting complication rates.

RESULTS

The median stone size was determined as 13 mm (range 10-20 mm). The stone-free rate was 83.6% after the first intervention. Reprocedure was applied to 89 of the patients with residual stones and the final stone-free rate was 94.4% after reprocedure. According to SCS, the number of intraoperative events and complication incidences was 153(16.1%). MCCS revealed postoperative complications in 121(12.8%) patients. Major complications were observed in 18(1.9%) patients. The rate of complications was higher in patients with renal anomalies (9.9% vs 3.4%, p=0.001). Stone location, stone size, stone burden, stone number, stone density and residual fragments were determined to be associated with the development of complications (p<0.001,p<0.001,p<0.001, p<0.001,p=0.002 and p<0.001 respectively). In addition, the multivariate analysis revealed that only presence of residual fragments was a significant predictor of complication development for the patients with Grade≥3 complications according to MCCS (p=0.032). However, significant predictors were stone burden (p<0.001), stone density (p=0.002) and fluoroscopy time (p<0.001) for those with Grade≥2b complications according to SCS.

CONCLUSION

This study showed that abnormal kidney anatomy, operation time, stone burden and residual fragments were reliable predictors of complication development during and after RIRS. Appropriate preoperative management should be planned according to these predictors to prevent intraoperative and postoperative complications.

Massive retroperitoneal hematoma as an acute complication of retrograde intrarenal surgery: A case report

BACKGROUND

Retrograde intrarenal surgery (RIRS) has been proven to be a safe and effective treatment modality in large-scale quantitative studies. However, although its safety profile has been established, it also has a potential risk of life-threatening complications. We here describe our experience with a patient who developed a huge periureteral hematoma after RIRS with holmium laser lithotripsy.

CASE SUMMARY

A 73-year-old woman visited our center with a complaint of gross hematuria. An enhanced computed tomography (CT) scan revealed a 1.5-cm left renal pelvis stone with hydronephrosis. The patient underwent RIRS. During the surgery, a 12/14-Fr ureteral access sheath was applied and a 6-Fr ureteral catheter was indwelled thereafter. On postoperative day 1, she experienced aggravated left flank pain and left lower-quadrant tenderness without rebound tenderness. A follow-up CT scan was taken, which revealed a huge hematoma in the periureteral space, not in the perirenal space, with suspicious contrast medium extravasation. Immediate angiography was performed; however, it showed no evidence of active bleeding. She was conservatively managed with hydration and antibiotic and nonsteroidal anti-inflammatory drug therapy, and was discharged on postoperative day 7. However, she visited our outpatient department with recurrent left flank pain at 5 d from discharge. Ultrasonography confirmed that the double J-stent was intact. To rule out stent malfunction, the stent was changed. Decreased size of the hematoma was observed in the imaging studies, and conservative management for candiduria was performed for 1 wk.

CONCLUSION

Although RIRS is an effective and safe procedure for the management of renal stones, clinicians should be aware of its potential complications.

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.

Risk factors of febrile urinary tract infections following retrograde intrarenal surgery for renal stones

We aimed to evaluate the risk factors of febrile urinary tract infection (UTI) following retrograde intrarenal surgery (RIRS) for treating renal stones.We retrospectively reviewed the data of patients with 10 - 30 mm kidney stones who underwent RIRS from January 2014 to July 2017. Evaluation included age, gender, body mass index, stone size, stone location, and operative time. All surgeries were performed by a single surgeon and ureteral stenting was not done prior surgery. The risk factors of febrile UTI after RIRS were assessed by univariate and multivariate logistic regression analysis.A total of 150 patients were included in the present study, and 17 patients (11.3%) had febrile UTI after RIRS. Mean patient age was 56.64 ± 13.91 years, and both genders were evenly distributed. Mean stone size was 14.16 ± 5.89 mm. and mean operation time was 74.50 ± 42.56 minutes. According to univariate analysis, preoperative pyuria was associated with postoperative febrile UTI. Multivariate logistic regression analysis showed that preoperative pyuria was the only independent risk factor of infectious complications after RIRS (odds ratios 8.311, 95% confidence intervals 1.759 - 39.275, P = .008). Age, gender, body mass index, comorbidity, preoperative bacteriuria, presence of hydronephrosis, renal stone characteristics, and operative time were not associated with febrile UTI after RIRS.Preoperative pyuria was the only risk factor of infectious complications following RIRS. Therefore, careful management after RIRS is necessary especially when preoperative urinalysis shows pyuria.

Radiation exposure to the urology surgeon during retrograde intrarenal surgery

Retrograde intrarenal surgery is a common procedure that carries a risk of radiation exposure for urologists. This study aimed to measure the amount of radiation that urologists are exposed to during surgery, and to estimate how many procedures can be safely performed by one urologist per year. Variables that affect radiation exposure were also identified. Radiation exposure doses were measured for the eye, neck, chest, arms, and hands of a urologist who performed 226 retrograde intrarenal surgeries. To determine how many procedures could be safely performed per year, the Annual Permissible Occupational Exposure Radiation Dose Guidelines of the National Council on Radiation Protection and Measurements were consulted. Correlations between radiation exposure dose and the patient's age, sex, body mass index, stone number/burden/laterality/location/Hounsfield unit, and their renal calculi were calculated. The mean surgery and fluoroscopy durations were 83.2 and 5.13 min; the mean tube voltage and current were 68.88 kV and 2.48 mA, respectively. Cumulative radiation doses for the eye, neck, chest, right upper arm, left hand, and right hand were 65.53, 69.95, 131.79, 124.43, 165.66, and 126.64 mSv, respectively. Radiation reduction rates for lead collars and aprons were 97% and 98%, respectively. If the urologists wear only radiation shields and lead apron but do not wear safety glasses during RIRS, the recommended by the ICRP publication 103 is taken into consideration, our results showed that 517 RIRS can be performed per year safely. However, if no protective measures are taken, this number decreases to only 85 RIRS per year. At all measurement sites, significant correlations were observed between the radiation exposure dose and stone numbers and Hounsfield unit values. In conclusion, it is imperative that urologists wear protective gear. Greater effort should be made to reduce radiation exposure when renal calculi have a large number of stones or large Hounsfield unit values.

The Impact of Stone Density on Operative Complications of Retrograde Intrarenal Surgery: A Multicenter Study with Propensity Score Matching Analysis

Background: The aim of the study was to evaluate the impact of stone density on operative complication rates in retrograde intrarenal surgery (RIRS). Materials and Methods: A total of 473 consecutive patients undergoing RIRS for the treatment of upper tract urinary stones were included. To adjust for baseline confounders, one-to-one propensity score matching was performed. After matching, the patients were divided into two groups according to stone density (low density [LD] group, ≤970 Hounsfield unit [HU]; high density [HD] group, >970 HU). The patients' demographics, stone-related features, stone-free rates, and intraoperative and postoperative complication rates were compared between the groups. The primary objective was to evaluate whether the intraoperative and postoperative complication rates were higher in patients whose stone density was greater than 970 HU. Results: After propensity score matching, 170 of 210 LD and 170 of 263 HD patients undergoing RIRS were included. The baseline characteristics did not differ significantly between the groups. There were no significant differences between LD and HD patients with respect to intraoperative (5.9% and 8.8%, respectively; P = .29), postoperative (10.6% and 15.3%, respectively; P = .14), and overall complication rates (15.2% and 21.1%, respectively; P = .16). Stone-free status was achieved in 143 patients (84.1%) in the LD group and 148 patients (87%) in the HD group; the difference was not statistically significant (P = .27). Conclusion: Our results show that RIRS is a safe and effective minimally invasive procedure for the treatment of upper urinary tract stones, even in HD stones.

Flexible ureteroscopy in extreme elderly patients (80 years of age and older) is feasible and safe

PURPOSE

To compare the safety and efficacy of RIRS in patients ≥ 80 years to a younger population.

METHODS

We retrospectively compared the data from patients ≥ 80 years of age undergoing RIRS with the data of a group of patients from 18 and < 80 years. Perioperative outcomes, complications and emergency department visits were compared between two groups.

RESULTS

A total of 173 patients were included in the study. Mean age was 44 (27-79) and 81 years-old (80-94), for younger and elderly group, respectively. Elderly patients had higher ASA scores (≥ 3) (28.6% vs 75.8%; p = 0.0001) and Charlson comorbidity index (1.99 vs 7.86; p = 0.0001), more diabetes (p = 0.006) and respiratory comorbidities (p = 0.002). No statistical difference was found between two groups in stone size (p = 0.614) and number (p = 0.152). Operative time (74.48 vs 102.96 min; p = 0.0001) and duration of hospitalisation (1.7 vs 2.9 days; p = 0.001) were longer for the elderly. Intraoperative complication rate did not show differences between the two groups (p = 0.166). Postoperative complications rates were similar between the cohorts (7.7% vs 9.5%; p = 0.682). The success rates were 67.5% in the younger group and 71.4% in the elderly group (p = 0.584). No difference was seen in stone recurrence (p = 0.73). A higher rate of visits to the emergency department was found in younger cohort (23.6% vs 11.6%; p = 0.046), mostly duo to stent-related symptoms.

CONCLUSIONS

Despite the higher rate of comorbidity in the elderly group, RIRS was a safe procedure with similar complication rate and outcomes at an expense of higher operative time and hospital stay.

Is plasma sterilization the modality of choice of sterilization today for endourological procedures such as ureterorenoscopy and retrograde intrarenal surgery? A single-center retrospective evaluation of 198 patients

Introduction:

The prevalence of infective complications among patients undergoing Retrograde Intrarenal Surgery (RIRS) for renal stone is 1.7%-18%, including fever, Systemic Inflammatory Response Syndrome (SIRS) and sepsis. The infectious complications of RIRS can be minimised by strict aseptic precautions and plasma sterilization. The Sterrad Next Generation (Sterrad NX) System, a low-temperature sterilizer represents the next generation of low-temperature hydrogen peroxide gas plasma sterilizers. This study was conducted to evaluate the efficacy of plasma sterilization among patients undergoing ureterorenoscopy (URS) and RIRS. The primary endpoint of this study was incidence of septicemia or related complications. Till date, there is no study on the incidence of infection rate in RIRS in relation to a specific mode of sterilization.

Material and Methods:

This is a retrospective study comprising of 198 patients undergoing URS and/or RIRS. The parameters studied were incidence of post-operative fever, Systemic Inflammatory Response Syndrome (SIRS), pyelonephritis or septicemic shock.

Results:

Out of 198 patients, incidence of post-operative fever was 3.5%, SIRS was 1.7%, pyelonephritis was 0.7% and septicemic shock was 0%. This is statistically significantly low septicemia rate among patients undergoing URS and /or RIRS as compared to the available literature. No health hazards of plasma sterilization were noted. No damage to the endoscopes or instruments was noted.

Conclusion:

Sterrad NX based on hydrogen peroxide gas plasma (HPGP) technology is highly efficacious, safe and the modality for sterilization of instruments, including heat labile instruments such as semi rigid, flexible and chip on the tip endoscopes and other EndoUrology armamentarium.

Comparative analysis of retrograde intrarenal surgery and modified ultra-mini percutaneous nephrolithotomy in management of lower pole renal stones (1.5-3.5 cm)

Background

To compare the safety and efficacy of retrograde intrarenal surgery (RIRS) and modified Ultra-mini percutaneous nephrolithotomy (UMP) in semi-supine combined lithotomy position for the management of 1.5–3.5 cm lower pole renal stones (LPSs).

Methods

A total of 63 patients with 1.5–3.5 cm LPSs who underwent RIRS (n = 33) or modified UMP (n = 30) in diameter between January 2017 and January 2019 were analyzed retrospectively. Modified UMP was performed in semi-supine combined lithotomy position and a 9.5/11.5 F ureteral access sheath (UAS) was inserted during the procedure in order to maintain low pelvic pressure and to facilitate the removal of stone fragments. Base-line parameters, stone characteristics, illness condition, operation time, postoperative hemoglobin (Hb) drop, postoperative creatinine (Cr) elevation, length of hospital stay, length of postoperative hospital stay, stone-free rate (SFR) and complications were compared between the two groups.

Results

There were no significant differences between the two groups in base-line parameters, stone characteristics and illness condition. The mean operating time of RIRS group was longer than UMP group (95.61 ± 21.9 vs. 55.0 ± 16.1 min, p < 0.001). The mean postoperative Hb drop was less in RIRS group (7.42 ± 4.7 vs. 15.70 ± 9.8 g/L, p < 0.001). The length of hospital stay and postoperative hospital stay for RIRS were shorter than UMP (4.76 ± 1.1 vs. 5.83 ± 0.8 d, p < 0.001, 2.97 ± 0.9 vs. 4.07 ± 0.9 d, p < 0.001). The Early SFR was higher in UMP group (54.5 vs. 80.0%, p < 0.050) while SFR at 1-month and 3-months postoperatively was similar in both groups (p = 0.504, p = 0.675). There were no significant differences between the two groups in complications (p = 0.228).

Conclusion

For patients with 1.5–3.5 cm LPSs, both modified UMP and RIRS are safe and viable. The modified UMP technique was used in this study, application semi-supine combined lithotomy position and the retention of UAS can improve the surgical efficiency and maintain low pressure perfusion in the kidney, which resulted in superior treatment efficacy. Therefore, we highly recommend this technique for LPSs with heavy stone burdens.

Sheathless and fluoroscopy-free retrograde intrarenal surgery: An attractive way of renal stone management in high-volume stone centers

Objective

To evaluate the efficacy and safety of sheathless and fluoroscopy-free flexible ureterorenoscopic laser lithotripsy (FURSL) for treating renal stones.

Methods

Between May 2015 and May 2017, 135 patients with renal stones treated with sheathless and fluoroscopy-free FURSL were prospectively evaluated. Our technique involved a semi-rigid ureteroscopic assessment of the ureter, and the guidewire was left in situ to railroad the flexible ureteroscope. A holmium laser was used to fragment and dust the stones; fragments were neither grasped nor collected.

Results

The study population consisted of 135 patients including 85 males (62.96%) and 50 females (37.04%) with a mean age of 40.65 years (range: 3–70 years) were evaluated. The mean stone size was 17.23 mm (range: 8–41 mm). Complete stone-free status was achieved in 122 (90.37%) patients and clinically insignificant residual fragments (CIRF) in two (1.48%), while residual stones were still present in 11 (8.15%) patients. Postoperative complications occurred in 23 (17.4%) cases and were mostly minor, including fever in 17 (12.6%), pyelonephritis in four (3.0%), subcapsular hematoma in one (0.7%) and steinstrasse in one (0.7%). These complications were Clavien I-II, GI in 17 (12.6%) patients, GII in five (3.7%), and Clavien IIIb in one (0.7%). No major complications were observed. Stone size ≥2 cm, operative time ≥30 min, and lasing time ≥20 min were significantly associated with a higher rate of complications and lower stone-free rates upon univariate analysis (p<0.05).

Conclusion

Sheathless and fluoroscopy-free FURSL are effective and safe for renal stone management, especially for stones under 2 cm in diameter. This process is a feasible option for avoiding sheath complications, which can protect surgeons from the negative effects of radiation.

Does Previous Failed Shockwave Lithotripsy Treatment Have an Influence on Retrograde Intrarenal Surgery Outcome?

Background: The prevalence of urolithiasis is nearly 20% and patients with urolithiasis constitute an essential part of the patients referred to the urology clinic. Many parameters should be considered for the management of renal stones and authors recommend extracorporeal shockwave lithotripsy (SWL), retrograde intrarenal surgery (RIRS), and percutaneous nephrolithotripsy (PNL), as treatment options. Among these techniques, SWL does not require general anesthesia, has 89% success rate for renal pelvic stones: 83% for upper caliceal stones, 84% for middle caliceal stones, and 68% for lower caliceal stones. In this study, we aimed to investigate whether the previously failed SWL treatment affects RIRS outcome. Methods: Patients who underwent RIRS for kidney stones between January 2012 and December 2017 in Diskapi Yildirim Beyazit Training and Research Hospital were reviewed retrospectively. Patients treated with primary RIRS (186 patients) were classified as Group 1. The outcomes of these patients were compared with those of 186 patients who underwent RIRS after failed SWL treatment using matched-pair analysis, and these patients were classified as Group 2. Results: The procedure success was defined as the sum of the stone-free and clinically insignificant residual fragments (CIRFs); final success rates were 90.3% and 91.9%, respectively. If we compare the final success rates, there was no statistically significant difference between both groups (P = .584). Conclusions: As a result, there is no negative effect of the previous unsuccessful SWL treatment on the RIRS success. Patients with CIRF should be followed up more carefully in terms of becoming symptomatic.

Digital Videoscopic Retrograde Intrarenal Surgeries for Renal Stones: Time-to-Maximal Stone Length Ratio Analysis

PURPOSE

To investigate 100 consecutive cases of videoscopic retrograde intrarenal surgery (RIRS) by a single surgeon and to evaluate factors associated with stone-free status and the learning curve thereof.

MATERIALS AND METHODS

We analyzed the results of videoscopic RIRS in 100 patients who underwent primary treatment for renal stones from January 2015 to August 2016. Videoscopic RIRS were performed with URF-V and URF-V2 flexible video uteroscopes (Olympus) or a Flex-Xc flexible ureterorenoscope (KARL STORZ). Non-contrast computed tomography was taken at 3 months postoperatively to confirm the absence of stones. The stone characteristics included the location, maximal stone length (MSL), stone heterogeneity index (SHI), and mean stone density (MSD). Fragmentation efficacy was calculated as operative time (min) divided by removed MSL (mm), and was evaluated in the sequential order of operations.

RESULTS

The mean age of the total patient was 60.0±14.0 years. The mean MSL was 13.1±6.2 mm. The average MSD was 734.2±327.6 Hounsfield unit (HU) and the SHI was 241.0±120.0 HU. The mean operation time was 65.1±45.7 min considering each renal unit. The stone-free rate at 3 months post-surgery was 87%. The estimated cut-off of the time-to-MSL ratio below 5 min/mm was 50. Multivariate analyses indicated a lower MSD [odds ratio (OR): 0.998; 95% confidence interval (CI): 0.996-0.999; p=0.047) and the last 50 cases (OR: 5.408, 95% CI: 1.337-30.426; p=0.030) as independent predictors of stone-free status after videoscopic RIRS.

CONCLUSION

Low MSDs and the last 50 cases were significant predictors of stone-free rate in videoscopic RIRS.

Is retrograde intrarenal surgery the game changer in the management of upper tract calculi? A single-center single-surgeon experience of 131 cases

Introduction:

Success of any modality for stone disease needs to be evaluated in terms of Stone Free Rates (SFR), auxiliary procedures needed; complications and follow up. SFR in RIRS is subject to parameters like stone burden, location, number, hardness, composition; calyceal and ureter anatomy; use of ureteric access sheath (UAS); surgeon experience etc.

Methods:

The aim of this study is to evaluate the efficacy and safety of RIRS for managing upper tract stones. The objectives include evaluating SFR in RIRS in relation to stone burden, location and number. Other objectives include evaluating SFR after re RIRS in relation to stone burden, necessity of pre DJ stenting, use of UAS and post operative complication rate. 131 patients operated by single surgeon for single/multiple renal and/or upper ureteric stones were evaluated. Stone size > 3 mm on follow up CT KUB was considered as residual. Re RIRS was required for residual stones.

Results:

The overall SFR was 76%. SFR were statistically lower with stone burden > 1.5 cm, lower calyceal stones and single stones with stone burden > 1.5 cm. SFR was 90% after 2^nd RIRS and 98.5% after 3^rd RIRS procedure. No significant difference in SFR was noted between single v/s multiple stones, single calyx v/s multiple calyx stones and renal v/s upper ureteric stones. No major complication was noted.

Conclusion:

Larger stone burden and lower calyceal location are important factors deciding SFR in RIRS. With auxiliary procedure, RIRS is safe and effective compared to PCNL.