Stone free rate and clinical complications in patients submitted to retrograde intrarenal surgery (RIRS): Our experience in 571 consecutive cases

Enhancing lithotripsy efficiency in retrograde intrarenal surgery via a flexible kidney-fixed position: findings from a prospective cohort study

Retrograde intrarenal surgery (RIRS) is recognized as an effective intervention for renal stones measuring less than 20 mm. This study aims to assess the efficacy and safety of a novel flexible kidney-fixed position compared to the conventional lithotomy position, focusing on lithotripsy efficiency and stone-free rates (SFR). A total of 100 patients undergoing unilateral RIRS between January 2023 and September 2024 were randomly allocated to either the conventional lithotomy position group or the kidney-fixed position group. Comparative analyses were conducted on demographic data, stone characteristics, intraoperative parameters, kidney movement metrics, and postoperative complications. A total of 97 patients successfully completed the study, with 47 participants assigned to the conventional lithotomy group and 49 to the kidney-fixed group. The kidney-fixed position was associated with a significant reduction in kidney movement (4.00 mm compared to 15.30 mm, p < 0.001) and a decrease in operative time (48.35 min versus 71.72 min, p < 0.001). Additionally, the SFR for stones measuring ≤ 4 mm was significantly higher in the kidney-fixed group (91.84% compared to 68.09%, p = 0.020). The implementation of a flexible kidney-fixed position markedly improves the efficacy of lithotripsy during RIRS, resulting in reduced operative time and an elevated SFR without a corresponding increase in postoperative complications. This technique holds promise for advancing the surgical management of renal calculi, warranting further investigation to substantiate these findings and assess long-term outcomes.

Cumulative sum analysis of the learning curve for retrograde intrarenal stone surgery in newbie surgeons

INTRODUCTION

This study investigated the learning curve of retrograde intrarenal surgery (RIRS) in patients with medium-sized stones using cumulative sum analysis (CUSUM) to evaluate the competence and proficiency of three new surgeons during their first RIRS procedures.

MATERIALS AND METHODS

We conducted a retrospective review of 227 patients from 2019 to 2022 at a single institution. The patients were divided into four groups based on the operating surgeon: tutor surgeon (85 patients), newbie surgeon A (21 patients), newbie surgeon B (85 patients), and newbie surgeon C (36 patients). Patients had one or multiple stones with the largest stone diameter fell within the range of 10-30 mm. Fragmentation efficacy was calculated as "removed stone volume (mm3) divided by operative time (minutes)." CUSUM analysis monitored changes in fragmentation efficacy and validated surgical outcomes.

RESULTS

No statistically significant differences were observed in the total stone volume, maximum stone size, or total operation time between the three newbie surgeons and the tutor surgeon. The mean fragmentation efficacy value was comparable among the newbie surgeons, but significantly different from that of the tutor surgeon. The minimum acceptable fragmentation efficacy level was set at 25.12 mL/min, based on the tutor's average value. The CUSUM curves for the three surgeons initially remained relatively flat until Cases 12-15, after which they increased and eventually plateaued. Stone-free rates and postoperative complications did not differ significantly among the surgeons.

CONCLUSION

Learning curve analysis for the three newbie surgeons indicated that approximately 12-15 cases were required to reach a plateau.

Active stone removal is a safe option for ocotogenarians and nonagenarians with nephrolithiasis

PURPOSE

To assess the contemporary in-hospital management of octogenarians and nonagenarians with renal calculi.

MATERIAL AND METHODS

A multicentric retrospective evaluation of patients aged ≥ 80 years hospitalized with kidney stones between 01/2000 and 12/2019. Stone and patient related data were collected, including stone size and location, geriatric status and comorbidities. Surgical treatment patterns and outcome were assessed.

RESULTS

A total of 299 patients (57% female) with kidney stones were analyzed. Mean age was 84.7 years. Patients were largely multimorbid (ASA ≥ 3 in 70%) and about 25% were classified as frail. Active stone treatment was performed in 65% and 35% were treated with urinary diversion (stent or nephrostomy). Prognostic factors for receiving an active stone treatment were age < 90 years, male sex, stone size and quantity, and performance status. Mean overall survival was 23.7 months and when stratified to treatment mean survival were 21 months after urinary diversion, 28 months after URS, 29 months after PCNL and 45 months after SWL.

CONCLUSION

Age, frailty and performance-status as well as stone size and quantity are predictors for active stone treatment. Octogenarians and nonagenarians, who are considered fit for surgery, tend to live long enough to profit from active stone treatment.

External validation of Resorlu-Unsal stone score in predicting outcomes after retrograde intrarenal surgery. Experience from a single institution

Objective: Pre-operative assessment of renal stones is essential in selecting treatment options and achieving high success rates for retrograde intrarenal surgery (RIRS). Several nephrolithometric scoring systems have been developed using pre-operative clinical data and stone characteristics. Resorlu-Unsal stone score (RUSS) is composed of four different parameters, and each of them adds 1 point to the final score. One point is added in patients with stone size > 20 mm, lower calyceal stones and infundibulo-pelvic angle < 45°, stone number > 1, and abnormal anatomy, respec-tively. RUSS categorizes patients into four distinct groups and aims to predict stone-free rates (SFR) after RIRS. We externally validated RUSS and evaluated its predictive accuracy.Materials and Methods: We performed a retrospective analysis of patients who underwent RIRS for renal stones between January 2020 and December 2021. Patient age, pre-operative hydronephrosis, stone size, stone density as Hounsfield Unit(HU), operative time and RUSS were investigated as potential preoperative predictive factors for stone-free status. RUSS was applied to all patients, and the nomogram was externally vali-dated. Area under the curve (AUC) was used for clinical validity assessment.Results: The present study included a total of 79 patients. Mean patient age was 55.1 ± 15.4 years with a mean stone size was 14.2 ± 4.4 mm. Overall, 62/79 (78.4%) patients were stone free after the initial treatment. After applying RUSS, 36 (45.6%), 29 (36.7%), 10 (12.6%), and 4 (5.1%) patients had a score of 0, 1, 2, and 3, respectively. On multivariate logistic regression RUSS (OR = 0.220; 95%CI: 0.086-0.567; p = 0.002) was identified as the only predictor of postoperative stone-free status.Conclusions: RUSS is a user-friendly scoring system that may predict postoperative stone-free rate after RIRS with great effi-cacy and accuracy.

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.