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

Risk factors of stone residual after retrograde intrarenal surgery: A prospective cohort study

BACKGROUND

Complete removal of renal stones is crucial for optimal patient outcomes, but recent studies have reported residual stones after retrograde intrarenal surgery (RIRS). This study aimed to identify the associated risk factors to improve patient management and treatment selection.

METHODS

This cohort study was conducted over 18 months at two hospitals and recruited adult patients with renal stones less than 3 cm. Preoperative assessment included medical history, physical examination, laboratory tests, and radiological imaging. Intraoperative and postoperative data collection and follow-up were conducted to evaluate surgical success and potential complications.

RESULTS

A total of 100 patients were included, with a mean age of 45.3 ± 10.7 years and a mean BMI of 26.2 ± 1.4 kg/m2. Approximately 19% of the patients had residual stones after the RIRS procedure. The RUSS score showed good diagnostic performance with an AUC of 0.843, and the optimal cut point was ⩾2.0 with a sensitivity of 52.6% and specificity of 95.1%. Independent predictors of residual stones were multiple sites (OR = 24.98; p = 0.002), multiple stones (OR = 13.62, p = 0.002), stone size of 21-30 mm (OR = 4.91, p = 0.038), lower calyx site (OR = 4.85, p = 0.033), and surgeon experience of fewer than 50 cases (OR = 6.82, p = 0.020).

CONCLUSIONS

This study identifies several factors associated with residual stones after RIRS for renal stones, including stone size, location, number, and surgeon experience. The study suggests that the RUSS score can be used as a reliable tool for predicting the likelihood of residual stones, which can help clinicians in patient selection and treatment planning.

Assessment of Factors Responsible for Stone-Free Status After Retrograde Intrarenal Surgery

Aim The study aimed to evaluate the predictive factors that determined stone-free rate (SFR) after retrograde intrarenal surgery (RIRS). Materials and methods This prospective study was conducted on 183 patients undergoing RIRS for renal stones. Patients were categorized into two groups, depending on stone-free status one month following the procedure. SFR was defined as the complete absence of stones or stones <4 mm. The parameters studied included patient demographics, presence of hydronephrosis, presence of preoperative double J-stent, abnormal renal anatomy, and stone characteristics (stone burden, stone number, stone density, stone location, lower pole infundibulopelvic angle, and lower pole renal infundibular length (RIL)). Univariate and multivariate analyses were performed to identify risk factors for residual stones. We assessed the predictive ability of the RIRS score and Resorlu-Unsal stone score (RUSS) for evaluating SFR utilizing receiver operating characteristic (ROC) analysis. Results 183 patients were included in the study with a median age of 51 years. 131 (71.6%) patients were declared stone-free after the procedure. The mean stone size and density were 16.9 SD±7.5 mm and 1038 SD±342 Hounsfield units (HU) respectively. Stone-free patients had lower stone size (14.3 mm vs. 23.6 mm, p<0.01) and stone density (970 HU vs. 1211 HU, p<0.01) compared to non-stone-free patients. Patients with residual stones had steeper lower pole renal infundibulopelvic angle (RIPA) (31.3° vs. 40.7°, p<0.01) and longer RIL (26.6 mm vs. 21.1 mm, p<0.01). Stone multiplicity (p<0.01), lower pole stone location (p<0.01), and renal malformations (p<0.01) were significant influencing factors for residual renal stones after RIRS. Multivariate analysis revealed stone size, stone density (HU), and stone location as independent predictors for SFR after RIRS. Among the scoring systems, the RIRS score had the highest diagnostic accuracy for SFR (area under the curve (AUC): -0.882, 95% CI-0.828-0.936). Conclusion Stone size, stone density (HU), and stone number are important predictors of SFR after RIRS. Lower pole stone location and abnormal renal anatomy play a substantial role in determining SFR after RIRS. In lower pole stones, a long RIL and acute RIPA negatively influence SFR. Additionally, the RIRS score was found to be a better predictor for SFR than the RUSS score.

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.

Updates in endourological management of urolithiasis

Urinary stone disease, or urolithiasis, is a very common disease with increasing prevalence and incidence. With the advancement of endoscopic techniques, the treatment outcomes of ureteroscopy (or transureteral lithotripsy) and percutaneous nephrolithotomy are continuously improving. In recent years, there have been many new developments in the field, including new endoscopy design, more effective auxiliary tools, improvement in treatment protocols, introduction of robotic technology, combining both ureteroscopy and percutaneous nephrolithotomy (endoscopic combined intrarenal surgery or transureteral lithotripsy-assisted percutaneous nephrolithotomy), improvement in laser technology, and so on. All these new inputs will further improve the treatment efficacy and safety of the procedures, thus benefiting our patients. In the present review, we briefly go through the main steps of ureteroscopy and percutaneous nephrolithotomy, with a concise description and application of these new advances.