Minimally invasive percutaneous nephrolithotomy versus retrograde intrarenal surgery in surgical management of upper urinary stones - A systematic review with meta-analysis

Optimal parameter settings of thulium fiber laser for ureteral stone lithotripsy: a comparative study in two different testing environments

This study aims to identify optimal parameters for using Thulium fiber lasers (TFL) in ureteral stone lithotripsy to ensure laser safety and maximize efficacy. Our goal is to improve the outcomes of single-use semi-rigid ureteroscopy for treating stones located in the proximal ureter. A clinically relevant thermal testing device was designed to investigate heating effects during TFL stone fragmentation. The device was utilized to identify safe power thresholds for TFL at various irrigation rates. Three other devices were used to assess varying pulse energy effects on stone fragmentation efficiency, dusting, retropulsion, and depth of tissue vaporization. Comparative experiments in fresh porcine renal units were performed to validate the efficacy and safety of optimal TFL parameters for semi-rigid ureteroscopy in proximal ureteral stone procedures. Our study found that the improved device generated a higher thermal effect. Furthermore, the safe power threshold for laser lithotripsy increased as the irrigation rate was raised. At an irrigation rate of 40 ml/min, it is safe to use an average power of less than 30 watts. Although increasing pulse energy has a progressively lower effect on fragmentation and dust removal efficiency, it did lead to a linear increase in stone displacement and tissue vaporization depth. Thermal testing showed 20 W (53.87 ± 2.67 °C) indicating potential urothelial damage. In our study of laser lithotripsy for proximal ureteral stones, the group treated with 0.3 J pulses had several advantages compared to the 0.8 J group: Fewer large fragments (> 4 mm): 0 vs. 1.67 fragments (1-2.25), p = 0.002, a lower number of collateral tissue injuries: 0.50 (0-1.25) vs. 2.67 (2-4), p = 0.011, and lower stone retropulsion grading: 0.83 (0.75-1) vs. 1.67 (1-2), p = 0.046. There was no significant difference in operating time between the groups (443.33 ± 78.30 s vs. 463.17 ± 75.15 s, p = 0.664). These findings suggest that TFL irradiation generates a greater thermal effect compared to non-irradiated stones. Furthermore, the thermal effect during laser lithotripsy is influenced by both power and irrigation flow rate. Our study suggests that using a power below 15 W with an irrigation flow rate of 20 ml/min is safe. Moreover, a pulse energy of 0.3 J appears to be optimal for achieving the best overall stone fragmentation effect.

Efficacy and safety of minimally invasive percutaneous nephrolithotomy versus retrograde intrarenal surgery in the treatment of upper urinary tract stones (> 1 cm): a systematic review and meta-analysis of 18 randomized controlled trials

BACKGROUND

The advantages and disadvantages of retrograde intrarenal surgery (RIRS) and minimally invasive percutaneous nephrolithotomy (mPCNL) for treatment of upper urinary tract calculi have not been conclusively determined.

METHODS

In this meta-analysis, We comprehensively evaluated the performance of the two surgical approaches in treatment of upper urinary calculi. We searched the Pubmed, Embase, Cochrane and Web of science databases for randomized controlled trial (RCT) articles on RIRS and mPCNL upto December 2022. Data were extracted by two independent reviewers and subjected to the meta-analysis using the Stata 15.1 software (StataSE, USA).

RESULTS

A total of 18 eligible RCTs involving 1733 patients were included in this study. The meta-analysis revealed that mPCNL of 1-2 cm or 2-3 cm stones had a higher stone clearance rate (RR:1.08, 95%CI (1.03, 1.14), p = 0.002) and shorter operation time (WMD : -10.85 min, 95%CI (-16.76, -4.94), p<0.001). However, it was associated with more hospital stay time (WMD :1.01 day, 95%CI(0.53, 1.5), p<0.001), hemoglobin drops (WMD :0.27 g/dl, 95%CI (0.14, 0.41), p<0.001), blood transfusion rate (RR:5.04, 95%CI(1.62, 15.65), p = 0.005), pain visual analogue score (WMD:0.75, 95%CI (0.04, 1.46), p = 0.037), hospital costs (SMD :-0.97, 95%CI (-1.19, -0.76), p<0.001) and major complications (RR:1.89, 95%CI(1.01, 3.53), p = 0.045).

CONCLUSION

Therefore, in terms of surgical effects and operation time, mPCNL is superior to RIRS, but is inferior with regards to other perioperative parameters. These factors should be fully considered in clinical decision making.

Mini-percutaneous nephrolithotomy versus retrograde intrarenal surgery for the treatment of 10-20-mm kidney stones in patients with ileal conduit: a comparative study

BACKGROUND

Both mini-percutaneous nephrolithotomy (mPNL) and retrograde intrarenal surgery (RIRS) are two major strategies for the endourological management of kidney stones. In the current study, we aimed to compare the efficacy and safety of mPNL and RIRS for the treatment of 10-20 mm kidney stones in patients with ileal conduit.

METHODS

Patients with a history of bladder cancer and ileal conduit who had undergone mPNL or RIRS for unilateral kidney stones 10-20 mm in size between January 2015 and June 2022 were retrospectively included. Baseline characteristics and perioperative outcomes were analyzed and compared between mPNL and RIRS.

RESULTS

The failure rate of the initial surgery was 2.5% and 18.9% for mPNL and RIRS, respectively (P=0.025). In total, 39 and 30 patients were finally included in the mPNL and RIRS groups. One-session stone-free rate (SFR) was higher in the mPNL group than the RIRS group (97.4% vs. 66.7%, P=0.002). However, there was no statistically significant difference between the two groups with regard to operation time, postoperative hospitalization, complications according to Clavien-Dindo classification, as well as the change in hemoglobin, creatinine, procalcitonin, and pain Visual Analogue Scale Score before and after the surgery. Moreover, Results were consistent across subgroup analyses in patients stratified by years (2015-2018 and 2019-2022).

CONCLUSIONS

Both mPNL and RIRS were feasible and safe for the treatment of 10-20 mm kidney stones in patients with ileal conduit. However, mPNL achieved superior SFR outcomes with a similar incidence of complications, and it might be a sensible alternative for selected patients.

Outcomes in Lower Pole Kidney Stone Management Using Mini-Percutaneous Nephrolithotomy Compared With Retrograde Intra Renal Surgery: A Randomized Controlled Trial

Background Because of the anatomical properties of the inferior calyx, lower pole stones are difficult to remove through the ureter, even if the stones are fragmented. Retrograde intra-renal surgery (RIRS) is typically employed to treat the smaller lower pole stones (1.0-2.0 cm) while percutaneous nephrolithotomy (PCNL) is primarily used to treat the larger diameter stones or when RIRS has failed to clear the stones. This study was conducted to compare mini-PCNL and RIRS for the management of lower pole kidney stones in terms of stone clearance. Material and methods This randomized control trial was conducted in the Department of Urology, Shaikh Zayed Hospital, Lahore from October 2020 to December 2022. A total of 150 patients between the ages of 18 and 80 years with a kidney stone size of 10-20 mm at the lower pole were included. Patients with positive urine culture, anatomical abnormalities, uncontrolled diabetes (hemoglobin{Hb}A1c >9%), and undergone previous renal surgery were excluded. Group A patients were treated with mini-PCNL, while group B patients were managed with RIRS. Follow-up visits were planned four weeks postoperatively with CT KUB (computed tomography of kidneys, ureters, and bladder) plain to assess stone clearance. Results The mean age in group A was 43.27 ± 13.86 years, while in group B was 45.32 ± 14.14 years. Out of 150 patients, 102 (68.0%) were males and 48 (32.0%) were females. Mean size of the stone was 15.30 ± 2.21 mm. Stone clearance after mini-PCNL was found in 69 (92.0%) patients and after RIRS in 59 (78.67%) patients (p-value = 0.021). Mean hospital stay after RIRS was 1.1 ± 0.09 days, while it was 2.3 ± 0.64 days after mini-PCNL (p-value < 0.001). Two (2.67%) patients in the mini-PCNL group developed bleeding postoperatively. The stone clearance rate in older patients (51 to 80 years) was significantly higher in the mini-PCNL group than RIRS group. Similarly, the stone clearance rate in female patients and in patients with larger stones (16 to 20 mm) was found to be higher in mini-PCNL group as compared to the RIRS group. Conclusion This study concluded that both mini-PCNL and RIRS are safe and efficient techniques for treating lower pole kidney stones with a size of 11-15 mm. However, mini-PCNL has a higher stone clearance rate compared to RIRS in the treatment of stones larger than 15 mm in size. This study further suggested that patients treated with mini-PCNL had a longer hospital stay compared to patients treated with RIRS.

Could retrograde intrarenal surgery be a safe and effective alternative to mini-percutaneous nephrolithotomy ın the management of relatively large (20-30 mm) stones? A critical evaluation

PURPOSE

To compare the outcomes of mini-percutaneous nephrolithotomy (mPCNL) and retrograde intrarenal surgery (RIRS) in patients with renal stones sizing 2-3 cm.

METHODS

A total of 566 patients from 6 institutions who underwent mPCNL (n = 440) and RIRS (n = 126) procedures were enrolled in our study. The retrospective patient cohort was reviewed and compared. Binary logistic regression analysis was performed to determine factors predicting success in the RIRS group.

RESULTS

The stone-free rates were 91.1 and 77% for the mPCNL and RIRS groups, respectively (p < 0.001). The auxiliary procedure rates were 4.5 and 39.7% in the mPCNL and RIRS groups, respectively (p < 0.001). Mean values of hemoglobin decrease, fluoroscopy time, and hospitalization time were significantly higher in the mPCNL group (p < 0.001). While the Clavien grade 1-2 complication rates were 10.9 and 34.1% (p < 0.001) in two groups, these values were 2.7 and 1.6% (p = 0.539), respectively, for Clavien grade 3-4 complication rates. Although three patients in the mPCNL group received blood transfusions, none of the patients in the RIRS groups were transfused. The stone location and stone density parameters were found to be the independent predictive factors for RIRS success.

CONCLUSIONS

mPCNL provided a higher stone-free rate, less need for the auxiliary procedure, and lower complication rates compared to RIRS in patients with 2-3 cm stones. Blood loss, radiation exposure, and a hospital stay of mPCNL can be significantly reduced with the RIRS technique in selected patients.

Retrograde Intrarenal Surgery Versus Miniaturized Percutaneous Nephrolithotomy for Kidney Stones >1cm: A Systematic Review and Meta-analysis of Randomized Trials

CONTEXT

Although miniaturized percutaneous nephrolithotomy (mPCNL) and retrograde intrarenal surgery (RIRS) are both options for treating >1cm kidney stones, controversies exist on whether one is more effective and safer than the other.

OBJECTIVE

To systematically appraise randomized trials comparing the effectiveness and safety of mPCNL and RIRS for treating >1cm kidney stones.

EVIDENCE ACQUISITION

A systematic search on PubMed/Medline, Web of Science, Embase, and ClinicalTrials.gov was conducted in August 2020 following the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA). Randomized trials comparing mPCNL and RIRS for >1cm kidney stones, and reporting stone-free rate (SFR), hemoglobin drop, transfusion rate, length of hospital stay (LOS), and/or complications, were included.

EVIDENCE SYNTHESIS

Eight studies compared mPCNL and RIRS, but one was not included due to its high risk of bias. SFR was higher for mPCNL (RR: 1.06 [95% coefficient interval {CI}, 1.01-1.10], p=0.008). Hemoglobin drop was higher for mPCNL (mean difference [MD]: 0.35 [95% CI, 0.05-0.65] g/dl, p=0.02); however, transfusion rates were similar (p=0.44). Complication rate was similar between mPCNL and RIRS (p=0.39), and the LOS was higher for mPCNL (MD: 1.11 [95% CI, 0.06-2.16] d, p=0.04). A subgroup analysis of lower pole stones showed that SFR was higher for mPCNL (RR: 1.09 [95% CI, 1.00-1.19], p=0.05).

CONCLUSIONS

Both approaches are effective and safe. Among these approaches, mPCNL has a higher SFR than RIRS for overall >1cm renal and lower pole stones, but longer LOS, and a higher hemoglobin drop that does not translate into higher transfusion rates. Complications are comparable.

PATIENT SUMMARY

Randomized trials have evaluated whether miniaturized percutaneous nephrolithotomy (mPCNL) or retrograde intrarenal surgery is more effective and safer for treating >1cm stones. After comparing the stone-free rate, hemoglobin drop, transfusion rate, length of hospital stay, and complications between both the approaches, mPCNL was found to be slightly more effective, but both were equally safe.

Flexible ureteroscopy versus miniaturized percutaneous nephrolithotomy for renal stones of 1-2 cm

Technological advances and innovation in endourology have significantly reduced the indications of extracorporeal shockwave lithotripsy in the management of moderate-sized renal stones. In the last decade, we have witnessed a trend towards the use of finer scopes for percutaneous procedures instead of standard percutaneous nephrolithotomy (PCNL) (≥22 Fr). Miniaturized PCNL (mPCNL), i.e. miniPCNL (12–20 Fr), ultra-miniPCNL (11–13 Fr), mini-microPCNL (8 Fr), and microPCNL (<5 Fr), is increasingly being used. Concomitant developments in laser technology have provided a safe and effective stone fragmentation modality for use via flexible ureteroscopes (fURS). Technological advances in the design of fURS have improved not only the optics (fiber optic to chip-on-the-tip technology digital image) but also the ergonomics. Both the endourological techniques are extremely effective and safe, as shown in a multitude of good-quality studies. There are some differences in stone-free rate and complications. mPCNL in general has a higher stone-free rate, albeit with a slightly higher incidence of hemorrhagic complications. fURS often requires longer stenting time and longer period to achieve stone clearance, whereas mPCNL often needs ureteral catheter for only 24 hours and has a higher first day stone-free rate. fURS is a 1 day procedure compared to mPCNL, which requires patients to stay hospitalized for 2–3 days. It is therefore important to tailor the indications of these two procedures to the individual patient’s needs.

Comparison of Mini-Percutaneous Nephrolithotomy and Retrograde Intrarenal Surgery for Renal Pelvic Stones of 2-3 cm

Backgrounds: Mini-percutaneous nephrolithotomy (M-PCNL) and retrograde intrarenal surgery (RIRS) are commonly used methods for the treatment of kidney stones. The aim of our study is to compare the effectiveness and safety of M-PCNL and RIRS for the treatment of renal pelvic stones with a diameter of 2-3 cm. Materials and Methods: The study included 250 patients, who underwent surgery for renal pelvic stones. M-PCNL and RIRS were performed on 130 and 120 patients, respectively. Age, gender, body mass index of the patients, stone size, the side of surgery, operative times, history of extracorporeal shock-wave lithotripsy, Hounsfield unit (HU) values, the length of hospital stay, stone-free rate (SFR), complication rates according to the modified Clavien system, postoperative hemoglobin loss, postoperative transfusion rates, postoperative narcotic analgesic use, and the number of secondary interventions were recorded. SFR in the postoperative first and third months were calculated. A chi-square test, Student's t-test, and the Wilcoxon test were used for statistical analyses. Results: No statistically significant differences were found in the demographic data, stone size, complication rates defined according to the modified Clavien system, HU values, and postoperative transfusion rates between the patient groups (P > .05). The success rate was statistically significantly higher regarding the postoperative first-month SFR in the M-PCNL group (P < .05). The postoperative third-month SFR after secondary interventions were similar between the groups. The examination of the postoperative hemoglobin loss and narcotic analgesic use and the length of hospital stay revealed superior results in the RIRS group (P < .05). Conclusion: M-PCNL and RIRS are effective and safe methods for the treatment of renal pelvic stones. M-PCNL is advantageous because of high SFR in the postoperative first month and the low need for secondary interventions, whereas RIRS has been found more advantageous in terms of the length of hospital stay, use of narcotic analgesics, and postoperative hemoglobin loss. Further studies on patients with multiple caliceal stones and on patients with a greater stone burden are needed.