Tubeless mini-percutaneous nephrolithotomy versus retrograde intrarenal surgery for lower calyceal stones of ⩽2 cm: A prospective randomised controlled study

Percutaneous nephrolithotomy vs retrograde intrarenal surgery for renal stones: a Cochrane Review

OBJECTIVES

To assess the effects of percutaneous nephrolithotomy (PCNL) vs retrograde intrarenal surgery (RIRS) for the treatment of renal stones in adults.

METHODS

We performed a comprehensive search of the Cochrane Library, MEDLINE, Embase, three other databases, trials registries, other sources of the grey literature, and conference proceedings up to 23 March 2023. We applied no restrictions on publication language or status. Screening, data extraction, risk-of-bias assessment, and certainty of evidence (CoE) rating using the Grading of Recommendations Assessment, Development and Evaluations (GRADE) approach were done in duplicate by two independent reviewers. This co-publication focuses on the primary outcomes of this review only.

RESULTS

We included 42 trials that met the inclusion criteria. Stone-free rate (SFR): PCNL may improve SFRs (risk ratio [RR] 1.13, 95% confidence interval [CI] 1.08-1.18; I2 = 71%; 39 studies, 4088 participants; low CoE). Major complications: PCNL probably has little to no effect on major complications (RR 0.86, 95% CI 0.59-1.25; I2 = 15%; 34 studies, 3649; participants; moderate CoE) compared to RIRS. Need for secondary interventions: PCNL may reduce the need for secondary interventions (RR 0.31, 95% CI 0.17-0.55; I2 = 61%; 21 studies, 2005 participants; low CoE) compared to RIRS.

CONCLUSION

Despite shortcomings in most studies that lowered our certainty in the estimates of effect to mostly very low or low, we found that PCNL may improve SFRs and reduce the need for secondary interventions while not impacting major complications. Ureteric stricture rates may be similar compared to RIRS. We expect the findings of this review to be helpful for shared decision-making about management choices for individuals with renal stones.

The Saudi urological association guidelines on urolithiasis

Aims

The Saudi Urolithiasis Guidelines are a set of recommendations for diagnosing, evaluating, and treating urolithiasis in the Saudi population. These guidelines are based on the latest evidence and expert consensus to improve patient outcomes and optimize care delivery. They cover the various aspects of urolithiasis, including risk factors, diagnosis, medical and surgical treatments, and prevention strategies. By following these guidelines, health-care professionals can improve care quality for individuals with urolithiasis in Saudi Arabia.

Panel

The Saudi Urolithiasis Guidelines Panel consists of urologists specialized in endourology with expertise in urolithiasis and consultation with a guideline methodologist. All panelists involved in this document have submitted statements disclosing any potential conflicts of interest.

Methods

The Saudi Guidelines on Urolithiasis were developed by relying primarily on established international guidelines to adopt or adapt the most appropriate guidance for the Saudi context. When necessary, the panel modified the phrasing of recommendations from different sources to ensure consistency within the document. To address areas less well covered in existing guidelines, the panel conducted a directed literature search for high quality evidence published in English, including meta analyses, randomized controlled trials, and prospective nonrandomized comparative studies. The panel also searched for locally relevant studies containing information unique to the Saudi Arabian population. The recommendations are formulated with a direction and strength of recommendation based on GRADE terminology and interpretation while relying on existing summaries of evidence from the existing guidelines.

Percutaneous nephrolithotomy versus retrograde intrarenal surgery for treatment of renal stones in adults

BACKGROUND

Kidney stones (also called renal stones) can be a source of pain, obstruction, and infection. Depending on size, location, composition, and other patient factors, the treatment of kidney stones can involve observation, shock wave lithotripsy, retrograde intrarenal surgery (RIRS; i.e. ureteroscopic approaches), percutaneous nephrolithotomy (PCNL), or a combination of these approaches.

OBJECTIVES

To assess the effects of percutaneous nephrolithotomy (PCNL) versus retrograde intrarenal surgery (RIRS) for the treatment of renal stones in adults.

SEARCH METHODS

We performed a comprehensive search of the Cochrane Library, MEDLINE, Embase, Scopus, and two trials registries up to 23 March 2023. We applied no restrictions on publication language or status.

SELECTION CRITERIA

We included randomized controlled trials that evaluated PCNL (grouped by access size in French gauge [Fr] into three groups: ≥ 24 Fr [standard PCNL], 15-23 Fr [mini-PCNL and minimally invasive PCNL], and < 15 Fr [ultra-mini-, mini-micro-, super-mini-, and micro-PCNL]) versus RIRS.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies and extracted data from the included studies. Our primary outcomes were stone-free rate, major complications, and need for secondary interventions. Our main secondary outcomes were unplanned medical visits to emergency/urgent care or outpatient clinic, length of hospital stay, ureteral stricture or injury, and quality of life. We performed statistical analyses using a random-effects model. We rated the certainty of evidence using GRADE criteria. We adopted a minimally contextualized approach with predefined thresholds for minimal clinically important differences (MCIDs).

MAIN RESULTS

We included 42 trials assessing the effects of PCNL versus RIRS in 4571 randomized participants. Twenty-two studies were published as full-text articles, and 20 were published as abstract proceedings. The average size of stones ranged from 10.1 mm to 39.1 mm. Most studies did not report sources of funding or conflicts of interest. The main results for the most important outcomes are summarized below. Stone-free rate PCNL compared with RIRS may improve stone-free rates (risk ratio [RR] 1.13, 95% confidence interval [CI] 1.08 to 1.18; I2 = 71%; 39 studies, 4088 participants; low-certainty evidence). Based on 770 participants per 1000 being stone-free with RIRS, this corresponds to 100 more (62 more to 139 more) stone-free participants per 1000 with PCNL (an absolute difference of 10%, where the predefined MCID was 5%). Major complications PCNL compared with RIRS probably has little or no effect on major complications (RR 0.86, 95% CI 0.59 to 1.25; I2 = 15%; 34 studies, 3649 participants; moderate-certainty evidence). Based on 31 complications in the RIRS group, this corresponds to six fewer (13 fewer to six more) major complications per 1000 with PCNL (an absolute difference of 0.6%, where the predefined MCID was 2%). Need for secondary interventions PCNL compared with RIRS may reduce the need for secondary interventions (RR 0.31, 95% CI 0.17 to 0.55; I2 = 61%; 21 studies, 2005 participants; low-certainty evidence). Based on 222 secondary interventions in the RIRS group, this corresponds to 153 fewer (185 fewer to 100 fewer) secondary interventions per 1000 with PCNL (an absolute difference of 15.3%, where the predefined MCID was 5%). Unplanned medical visits No studies reported unplanned medical visits. Length of hospital stay PCNL compared with RIRS may extend length of hospital stay (mean difference 1.04 days more, 95% CI 0.27 more to 1.81 more; I2 = 100%; 26 studies, 2804 participants; low-certainty evidence). This effect size is greater than the predefined MCID of one day. Ureteral stricture or injury PCNL compared with RIRS may have little or no effect on the occurrence of ureteral strictures (RR 0.93, 95% CI 0.39 to 2.21; I2 = 0%; 13 studies, 1574 participants; low-certainty evidence). Based on 14 ureteral strictures in the RIRS group, this corresponds to one fewer (nine fewer to 17 more) ureteral strictures per 1000 with PCNL (an absolute difference of 0.1%, where the predefined MCID was 2%). Quality of life No studies reported quality of life.

AUTHORS' CONCLUSIONS

Based on a large body of evidence from 42 trials, we found that PCNL compared with RIRS may improve stone-free rates and may reduce the need for secondary interventions, but probably has little or no effect on major complications. PCNL compared with RIRS may have little or no effect on ureteral stricture rates and may increase length of hospital stay. We found no evidence on unplanned medical visits or participant quality of life. Because of the considerable shortcomings of the included trials, the evidence for most outcomes was of low certainty. Access size for PCNL was less than 24 Fr in most studies that provided this information. We expect the findings of this review to be helpful for shared decision-making about management choices for individuals with renal stones.

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.

Minimally invasive nephrolithotomy versus retrograde intrarenal surgery in surgical management of Lower calyceal stones: a systematic review with meta-analysis

OBJECTIVE

The efficacy and safety of minimally invasive nephrolithotomy (MPCNL) versus retrograde intrarenal surgery (RIRS) was assessed for lower calyceal (LC) stones.

METHODS

Our team conducted a systematic literature search up to December, 2022, using PUBMED, EMBASE and the Cochrane Library. The study was registered in PROSPERO, CRD 42021247197. Randomized controlled trials evaluating the efficacy and safety of MPCNL versus RIRS for LC stones were collected. Heterogeneity among the studies was assessed using the χ 2 test based on the Q and I2 tests. Pooled effect sizes were calculated using a fixed model if I2 is less than 50%; otherwise, a random-effects model was chosen. The primary outcomes were the 3-month stone-free rate (3SFR) and total complications, while the secondary outcomes were the operating time, hospital stay, haemoglobin reduction, bleeding, postoperative fever and complications with the Clavien-Dindo system. A subgroup analysis of 10-20 mm LC stones was also designed.

RESULTS

A total of 7 peer-reviewed trials comprising 711 patients were identified. No statistical differences were observed in the heterogeneity results of the 3SFR or total complications ( P >0.1, I2 < 50%). Compared with RIRS, MPCNL had an unfavourable safety profile, resulting in total complications [odds ratio (OR): 1.87 (95% CI: 1.05, 3.33); P =0.03], haemoglobin reduction [OR: 0.81 (95% CI: 0.15, 1.47); P =0.02] and complications with Grade I [OR: 5.52 (95% CI: 1.34, 22.83); P =0.02] but an improved efficacy and 3SFR [OR: 2.43 (95% CI: 1.48, 3.97); P =0.0004]. As for the 10-20 mm LC stones, compared with RIRS, MPCNL also had an unfavourable safety profile, resulting in total complications [OR: 2.47 (95% CI: 1.20, 5.07); P =0.01], complications with Grade I [OR: 4.97 (95% CI: 0.99, 25.01); P =0.05] and an increased hospital stay [OR: 2.46 (95% CI: 2.26, 2.66); P =0.00001] but an improved efficacy and 3SFR {OR: 3.10 (95% CI: 1.61, 5.99); P =0.0008]. The efficacy effect of MPCNL and safety effect of RIRS were nearly equal for both stones sized less than 20 mm (number needed to treat = 17, number needed to harm = 20) and stones sized 10-20 mm (number needed to treat = 20, number needed to harm = 13). No statistical difference was found between the MPCNL and RIRS groups for the rest of outcomes.

CONCLUSION

Both MPCNL and RIRS are safe and effective management methods. Moreover, compared with RIRS, MPCNL had an unfavourable safety profile but improved efficacy for LC stones of ≤20 mm or 10-20 mm, and the differences were statistically significant. The relative profit of efficacy of MPCNL was similar to the relative profit of safety of RIRS.

Comparison between standard, mini and ultra-mini percutaneous nephrolithotomy for single renal stones: a prospective study

PURPOSE

Based on the current trend of miniaturization of instruments used in percutaneous nephrolithotomy (PCNL), it is necessary to compare different PCNL modalities regarding their access sheath size used. Thus, the safety and efficacy among standard, mini and ultra-mini PCNL (s-PCNL, m-PCNL, um-PCNL) were compared.

METHODS

We performed a prospective, non-randomized trial between January 2018 and July 2020. Patients with stones classified as Guy's stone score grade I were included. The set-up for s-PCNL and m-PCNL included a 30 Fr and 22 Fr percutaneous tract, respectively. In both set-ups, an ultrasonic/ballistic lithotripter was utilized. In the case of um-PCNL, a 12 Fr percutaneous tract was established. A high-power laser was used for lithotripsy. Hemoglobin drop, complication rate, length of hospital stay (LOS), stone-free rate (SFR) and operation time were evaluated.

RESULTS

A total of 84 patients, 28 patients per method, were evaluated. Hemoglobin drop was higher in the s-PCNL group when compared to m-PCNL (p = 0.008) and um-PCNL groups (p < 0.001), while um-PCNL group had the slightest hemoglobin drop. LOS was similar between s-PCNL group and m-PCNL group, but um-PCNL group required shorter hospital stay than the other two modalities (p < 0.001). The complication and transfusion rates as well as SFR did not differ between groups. Operation time in the um-PCNL set-up was longer compared to s-PCNL (p < 0.001) and m-PCNL (p = 0.011), whereas s-PCNL and m-PCNL did not differ significantly.

CONCLUSION

m-PCNL showed less hemoglobin drop, but similar operation time and SFR when compared to s-PCNL. um-PCNL showed even less hemoglobin drop, but the operation time was longer compared to the two other modalities.

Infectious complications of endourological treatment of kidney stones: A meta-analysis of randomized clinical trials

OBJECTIVE

Endourological treatment is associated with a risk of postoperative febrile urinary tract infections and sepsis. The aim of this study was to review the reported rate of infectious complications in relation to the type and modality of the endourologic procedure.

METHODS

This systematic review was conducted in accordance with the PRISMA guidelines. Two electronic databases (PubMed and EMBASE) were searched. Out of 243 articles retrieved we included 49 studies after full-text evaluation.

RESULTS

Random-effects meta-analysis demonstrated that retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) were associated with not significantly different odds of getting fever (OR = 1.54, 95% CI: 0.99 to 2.39; p = 0.06) or sepsis (OR = 1.52, 95% CI: 0.37 to 6.20, p = 0.56). The odds of getting fever were not significantly different for mini PCNL compared to standard PCNL (OR = 1.11, 95% CI: 0.85 to 1.44; p = 0.45) and for tubeless PCNL compared to standard PCNL (OR = 1.34 95% CI: 0.61 to 2.91, p = 0.47). However, the odds for fever after PCNL with suctioning sheath were lower than the corresponding odds for standard PCNL (OR = 0.37, 95% CI: 0.20 to 0.70, p = 0.002). The odds of getting fever after PCNL with perioperative prophylaxis were not different from the corresponding odds after PCNL with perioperative prophylaxis plus a short oral antibiotic course (before or after the procedure) (OR = 1.31, 95% CI: 0.71 to 2.39, p = 0.38).

CONCLUSIONS

The type of endourological procedure does not appear to be decisive in the onset of infectious complications, although the prevention of high intrarenal pressure during the procedure could be crucial in defining the risk of infectious complications.   on behalf of U-merge Ltd. (Urology for emerging countries), London-Athens-Dubai.

Flexible ureterorenoscopy (RIRS) vs. Mini- percutaneous nephrolithotomy (MINI-PCNL) for renal stones 20–30 mm a prospective randomized study

Background

To evaluate the safety and efficacy of mini percutaneous nephrolithotomy (mini PCNL) and retrograde intrarenal surgery (RIRS) in treatment of kidney stones 20–30 mm.

Methods

A prospective randomized study of 70 patients who presented to the urology department with calyceal or renal pelvic stone of 20–30 mm between September 2017 and September 2019. Patients were randomly divided into two groups, Group A (Mini PCNL) consists of 35 patients who were treated with mini PCNL and Group B (RIRS) consists of 35 patients who were Achieving success of the technique was considered when the patient is stone-free or has radiologically insignificant residual fragments < 4 mm.

Results

The demographic data in this study were comparable in both groups. The stone size was 20.43 ± 2.2 mm in group A & 20.5 ± 2.1 in group B, with no statistical significance. Meanwhile, the operative time in group A was 59.71 ± 19.44 min and in group B was 80.43 ± 14.79 min with statistical significance difference (p value < 0.001), while Fluoroscopy time had a mean of 8.11 ± 2.05 min in group A & 5.8 ± 1.98 min in group B with statistically significant diffrence (p value < 0.001). The stone free rate (SFR) was 88.6% in mini PCNL and 82.9% in RIRS with no statistically significant difference (p value: 0.5).

Conclusion

RIRS and mini PCNL can be an effective and alternative option for treatment of renal stones 2–3 cm. Both techniques have relatively similar SFR but RIRS showed more operative time, on contrary Mini-PCNL has more operative and postoperative complications. A multicenter studies with larger numbers of patients will be more effective to confirm these results.

Initial Safety and Feasibility of Steerable Ureteroscopic Renal Evacuation (SURE), A Novel Approach for the Treatment of Urolithiasis

Background:

There is a need to reliably render urolithiasis patients completely stone free with minimal morbidity. We report on the initial safety and feasibility with steerable ureteroscopic renal evacuation (SURE) in a prospective study using basket extraction as a comparison.

Materials and Methods:

A pilot randomized controlled study was conducted comparing SURE with basket extraction postlaser lithotripsy. SURE is performed using the CVAC™ Aspiration System, a steerable catheter (with introducer). The safety and feasibility of steering CVAC throughout the collecting system under fluoroscopy and aspirating stone fragments as it was designed to do were evaluated. Fluoroscopy time, change in hemoglobin, adverse events through 30 days, total and proportion of stone volume removed at 1 day, intraoperative stone removal rate, and stone-free rate (SFR) at 30 days through CT were compared.

Results:

Seventeen patients were treated (n = 9 SURE, n = 8 Basket). Baseline demographics and stone parameters were not significantly different between groups. One adverse event occurred in each group (self-limiting ileus for SURE and urinary tract infection for Basket). No mucosal injury and no contrast extravasation were observed in either group. The CVAC catheter was steered throughout the collecting system and aspirated fragments. There was no significant difference in fluoroscopy time, procedure time, change in hemoglobin, or stone removal rate between groups. SURE removed more and a greater proportion of stone volume at day 1 vs baskets (202 mm³vs 91 mm³, p < 0.01 and 84% vs 56%, p = 0.022). SURE achieved 100% SFR at 30 days vs 75% for baskets, although this difference was not statistically significant (p = 0.20).

Conclusions:

This initial study suggests SURE is safe, feasible, and may be more effective in stone removal postlaser lithotripsy compared to basketing. More development is needed, and larger clinical studies are underway.

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.

Comparison of the outcomes of flexible ureteroscopy and mini-percutaneous nephrolithotomy for the treatment of kidney stones: a matched-pair analysis

OBJECTIVE

Mini-percutaneous nephrolithotomy is a recent advancement in the field of kidney stone treatment; however, its role has not been completely established. We aimed to compare the outcomes of initial Mini-percutaneous nephrolithotomy and flexible ureteroscopy.

METHODS

A retrospective review of consecutive mini-percutaneous procedures was performed. Inclusion criteria were as follows: all percutaneous nephrolithotomy procedures performed with an access sheath up to 24Fr, kidney stone burdens up to 1550 mm3; and the presence of postoperative computed tomography (for control). The data collected for Mini-percutaneous nephrolithotomy procedures were paired 1:2 with patients treated with flexible ureteroscopy for stones between 100 and 1550 mm3, and with postoperative computed tomography for control. A 14Fr Mini-percutaneous nephrolithotomy set was used. The stone-free rate was defined as the absence of fragments on the control computed tomography, whereas success was limited to 2-mm residual fragments. Statistical analysis was performed using SPSS version 19.

RESULTS

A total of 63 patients met the inclusion criteria (42 with flexible ureteroscopy and 21 with mini-percutaneous nephrolithotomy). Demographic data were comparable. The stone-free rate and success were similar between the groups (76.2 vs. 66.7%, p=0.42 and 90.5 vs. 85.7%, p=0.57). The complication rate was also similar (26.1 vs. 9.6%, p=0.188), but Mini-percutaneous nephrolithotomy had longer hospitalization and fluoroscopy time (p=0.001 in both).

CONCLUSIONS

Our initial study of Mini-percutaneous nephrolithotomy showed that it is a promising procedure, with outcomes similar to flexible ureteroscopy, but with higher inpatient numbers and fluoroscopy times. A larger study population size and better equipment may improve the outcomes of mini-percutaneous nephrolithotomy.

Size Distribution of Fragments by High-power Holmium Laser Lithotripsy in MiniPCNL with Suction

PURPOSE OF REVIEW

Data are lacking on distribution of size of fragments created with the laser lithotripsy, stone density, and composition. Dust (< 1 mm) and small fragments (1-3 mm) may be too small to be efficiently removed with forceps compared to larger fragments (> 3 mm). We aim to report the size distribution of fragments formed during holmium laser lithotripsy.

RECENT FINDINGS

One hundred ten patients with renal calculi < 3 cm underwent miniPCNL using ClearPetra sheath (Well Lead Medical Co., China) with controllable irrigation and suction system that minimizes fragment dispersion and maximizes fragment aspiration. Moses holmium laser (Lumenis INC, Israel) was used with predefined laser energy settings for lithotripsy. Proportion of fragment size < 1 mm was 46.36 ± 16.68%, 1-3 mm was 28.18 ± 10.01%, and > 3 mm was 25.19 ± 16.18% for the entire cohort. Complete stone clearance at 48 h was achieved in 77.3% cases. The remaining 22.7% patients had complete clearance at 1-month follow-up CT. In all the stone density, volume, and composition groups, majority of fragments created were either < 1 mm or 1-3 mm. Only 25% fragments were > 3 mm that would get aspirated out through the sheath with suction or could be retrieved with forceps. The combination of a high-power holmium laser and suction would help in complete stone clearance with effective aspiration of smaller stone fragments and dust simultaneously during lasing.

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.

Miniaturized percutaneous nephrolithotomy versus retrograde intrarenal surgery in the treatment of lower pole renal stones

OBJECTIVES

Miniaturization of percutaneous nephrolithotomy techniques have led to their increased consideration for lower pole renal stones that can prove more challenging to reach using retrograde intrarenal surgery. The objectives of the present study were to evaluate and compare the outcomes of miniaturized percutaneous nephrolithotomy (miniPCNL) and retrograde intrarenal surgery (RIRS) for the treatment of lower pole renal stones.

MATERIALS AND METHODS

A retrospective study was performed in two academic urology departments between January 2016 and June 2019. Patients presenting with one or multiple stones of the lower calyx and/or renal pelvis, between 10 and 40mm based on CT-scan treated by miniPCNL or RIRS were included.

RESULTS

In all, 115 miniPCNL and 118 RIRS procedures were included. The rate of patients with no significant residual fragment (stone free rate) after the first procedure was higher in the miniPCNL group (69% vs. 52% P=0.01), especially for stones>20mm (63% vs. 24% respectively, P<0.001) and stones with a density≥1000HU (69% vs. 42% respectively, P=0.009). The higher stone free rate of miniPCNL was confirmed in multivariate analysis, adjusting for stone size and number of stones, OR 4.02 (95% CI 2.08-8.11, P<0.0001). The overall postoperative complication rate was higher in the miniPCNL group than in the RIRS group (23% vs. 11%, P=0.01). A second intervention for the treatment of residual fragments was necessary for 9.6% of patients in the miniPCNL group versus 30.5% of patients in the RIRS group (P<0.001). Pre-stenting rate and duration of ureteral drainage (2 [1-8] vs. 25 days [7-37], P<0.001) were lower in the miniPCNL group.

CONCLUSIONS

The stone free rate was higher after miniPCNL, especially for stones>20mm and with a density>1000 HU, but was associated with a higher risk of postoperative complications and a longer hospital stay. RIRS resulted in fewer complications at the cost of a higher retreatment rate and longer ureteral stenting.

LEVEL OF EVIDENCE

3.

The best treatment approach for lower calyceal stones ≤ 20 mm in maximal diameter: mini percutaneous nephrolithotripsy, retrograde intrarenal surgery or shock wave lithotripsy. A systematic review and meta-analysis of the literature conducted by the European Section of Uro-Technology and Young Academic Urologists

INTRODUCTION

The highest in quality data in the literature which compared mini percutaneous nephrolithotripsy (mPCNL), retrograde intrarenal surgery (RIRS) and shock wave lithotripsy (SWL) for the management of lower pole stone (LPS) with a maximal diameter ≤20mm were investigated by means of systematic review (SR) and meta-analysis.

EVIDENCE ACQUISITION

A SR of the literature was conducted on PubMed®, Cochrane, SCOPUS® and EMBASE® in January 2020. The study complied with the PRISMA statement and recommendations of the EAU Guidelines office. Only randomized controlled trials (RCTs) comparing retrograde intrarenal surgery (RIRS), shock wave lithotripsy (SWL) and mini-percutaneous nephrolithotripsy (mPCNL) were selected for the meta-analysis. The endpoints were the efficacy of each modality, measured by stone-free rate (SFR), operative time and retreatment rate and the safety of each method, based on hospitalization time and complications. Subgroup analyses for stones with a maximal diameter <10mm and 10-20 mm were performed.

EVIDENCE SYNTHESIS

Twenty-one RCTs were included in the meta-analysis. mPCNL had the highest SFR and the lowest retreatment rate among the three modalities, while SWL had the lowest SFR and the highest retreatment rate. The operative and hospitalization time were shorter in the case of SWL, whereas they were similar in the case of mPCNL and RIRS. The highest complication rate was observed in mPCNL group, which accounted for 8.3-22.4%, while RIRS and SWL had similar complication rates, which ranged between 1.3-31.4% and 0-48.5%, respectively. Further classification of the complications according to Clavien-Dindo system revealed that SWL had lower grade II complication rates compared to mPCNL and RIRS. Regarding stones <10mm, SWL and RIRS had similar SFR, complication rate, operation and hospitalization time. SWL had higher retreatment rate.

CONCLUSIONS

For LPSs ≤20mm, mPCNL provides the highest SFR and the lowest retreatment rate. This modality has a higher complication rate and longer hospital stay in comparison to the other modalities. SWL provides the lowest SFR with the highest retreatment rate. RIRS has similar complication rate to SWL and could be preferred over SWL. For stones up to 10mm, SWL may provide a valid alternative. Despite a higher retreatment rate, its SFR is similar to RIRS.

Miniaturized Ambulatory Percutaneous Nephrolithotomy Versus Flexible Ureteroscopy in the Management of Lower Calyceal Renal Stones 10-20 mm: A Propensity Score Matching Analysis

OBJECTIVE

To evaluate the efficacy of ambulatory mini percutaneous nephrolithotomy (Mini-PCNL) and flexible ureteroscope (F-URS) in treating 10-20 mm lower calyceal stones using propensity score matching analysis (PSM).

PATIENTS AND METHODS

A retrospective analysis of 136 adult patients that underwent Mini-PCNL or F-URS for a single lower calyx calculus. Participants that underwent F-URS were allocated to Group I, while those who underwent Mini-PCNL were assigned to Group II. Patients were discharged on the same day and followed up by CT after 3 months. Both groups were matched by stone size and density using propensity stone matching (PSM) and the matched group were further compared.

RESULTS

Before matching, there were statistical differences in stone size (P = .02), preoperative hydronephrosis (P = .004), and Hounsfield Unit (P = .04) between both groups. A logistic regression model was created between independent variables such as stone size and density. The new groups following PSM were statistically similar in terms of age, BMI, stone size, and HFU (P = .43, P = .74, P = .49, P = .36). The stone-free rates after PSM was not significantly higher in the Mini-PCNL group than the F-URS group (91.7% vs 81.7%, respectively P = .1) while the operative time for the F-URS group was significantly shorter than the Mini-PCNL group 54 (49-64.3) minutes vs 68.2 (62-73.5) minutes, respectively, P = .045.

CONCLUSION

Ambulatory Mini-PCNL and F-URS have a comparable hospital stay, stone-free rates, and complication rates for treating lower calyceal stones 10-20 mm. Both techniques may be considered acceptable treatment options, with a prolonged operative time in Mini-PCNL.

Precision Stone Surgery: Current Status of Miniaturized Percutaneous Nephrolithotomy

PURPOSE OF REVIEW

Innovations in lasers and surgical technology have led to a renewed interest in the miniaturization of percutaneous nephrolithotomy (PCNL). We review the different approaches and evidence on the efficacy of mini-PCNL.

RECENT FINDINGS

Mini-PCNL encompasses a range of techniques using tract sizes from 4.8 to 22 F to treat renal stones. The most common device uses irrigation to passively extract stones out of the sheath. Super-mini-PCNL incorporates active suction. Ultra- and micro-techniques reduce the tract to smaller diameters. Laser fragmentation is the main lithotripsy modality. Studies demonstrate an association with reduced complications, hospital stay, and increased tubeless rate. Drawbacks include longer operative times while stone-free rates for larger stones may be sub-optimal. Mini-PCNL has advantages of less trauma and the avoidance of nephrostomy tubes. Ambulatory surgery is feasible in select patients. Advances in laser lithotripsy and active suction have the potential to improve stone clearance and treat larger stones.

Consultation on kidney stones, Copenhagen 2019: aspects of intracorporeal lithotripsy in flexible ureterorenoscopy

Purpose

To summarize current knowledge on intracorporeal laser lithotripsy in flexible ureterorenoscopy (fURS), regarding basics of laser lithotripsy, technical aspects, stone clearance, lithotripsy strategies, laser technologies, endoscopes, and safety.

Methods

A scoping review approach was applied to search literature in PubMed, EMBASE, and Web of Science. Consensus was reached through discussions at the Consultation on Kidney Stones held in September 2019 in Copenhagen, Denmark.

Results and conclusions

Lasers are widely used for lithotripsy during fURS. The Holmium laser is still the predominant technology, and specific settings for dusting and fragmenting have evolved, which has expanded the role of fURS in stone management. Pulse modulation can increase stone ablation efficacy, possibly by minimizing stone retropulsion. Thulium fibre laser was recently introduced, and this technology may improve laser lithotripsy efficiency. Small fibres give better irrigation, accessibility, and efficiency. To achieve optimal results, laser settings should be adjusted for the individual stone. There is no consensus whether the fragmentation and basketing strategy is preferable to the dusting strategy for increasing stone-free rate. On the contrary, different stone scenarios call for different lithotripsy approaches. Furthermore, for large stone burdens, all laser settings and lithotripsy strategies must be applied to achieve optimal results. Technology for removing dust from the kidney should be in focus in future research and development. Safety concerns about fURS laser lithotripsy include high intrarenal pressures and temperatures, and measures to reduce both those aspects must be taken to avoid complications. Technology to control these parameters should be targeted in further studies.

A clinical experience of thulium fibre laser in miniperc to dust with suction: a new horizon

PURPOSE

To report safety and efficacy of mini-PCNL with suction attached to sheath combined with high-power Thulium Fibre laser (TFL). The secondary aim was to evaluate optimal laser settings for maximum stone dusting.

MATERIALS AND METHODS

Prospective, single arm study was conducted from June 2019-December 2019 using miniPCNL with suction and TFL in 54 patients with renal stones < 3 cm. Stone fragments for each laser setting were independently retrieved and segregated according to size(< 1 mm,1-3 mm, > 3 mm) and weighed. Xray/CT scan imaging was performed in all patients within 48 h and 30 days to assess stone clearance. Optimal laser settings were evaluated for maximum dusting.

RESULTS

Mean stone size was 18.32 ± 6.37 mm, volume was 2337.75 ± 1996.84mm³ and stone density was 1300.55 ± 435.32 HU. Total operative time was 39.85 ± 20.52 min, laser time was 10.08 ± 7.41 min and stone fragmentation rate was 5.02 ± 3.93 mm³/s. The procedure was completely tubeless in 37.04%, nephrostomy tube in 37.04% and DJ stent placed in 25.92%. Postoperatively, three patients had urinary infection (Clavien 2). Complete stone clearance at 48 h was achieved in 35 (64.8%) cases. 19 patients (35.2%) who had residual fragments at 48 h, had 100% clearance at one month on CT/Xray KUB.

CONCLUSIONS

MiniPCNL using a nephrostomy sheath with suction along with high power Thulium Fibre Laser is safe and effective modality for lithotripsy. An initial laser setting of 0.2 J and 125-200 Hz was optimal for maximum dusting and simultaneous aspiration. Randomized comparative studies with other energy sources are being considered.

Minimally invasive percutaneous nephrolithotomy (PCNL): Techniques and outcomes

Minimally invasive percutaneous nephrolithotomy (PCNL) was introduced to decrease the morbidity of the standard PCNL (sPCNL). Thereafter, many modifications and techniques have been presented with the introduction of different miniaturized PCNL (mPCNL) techniques, such as micro-PCNL and ultra-mini-PCNL (UMP). As of present, none of the techniques has displaced the sPCNL. Nonetheless, mini-PCNL has continuously widening indications and has been proposed to have significant advantages over sPCNL. In the current review, each technique is presented while discussing the advantages and disadvantages of each approach. A comprehensive review of the current literature has been performed. Articles related to the topic were retrieved and critically analyzed. Less peri-operative bleeding and shorter hospital stay were the most important advantages advocated for mini-PCNL. Although the performance of mini-PCNL is safe, the utilization of micro-PCNL and UMP should be done with caution.

Comparison of the efficacy and safety of shockwave lithotripsy, retrograde intrarenal surgery, percutaneous nephrolithotomy, and minimally invasive percutaneous nephrolithotomy for lower-pole renal stones: A systematic review and network meta-analysis

BACKGROUND

Shock wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS), percutaneous nephrolithotomy (PCNL), and minimally invasive PCNL are currently therapeutic options for lower-pole renal stones (LPS). However, the optimal treatment for LPS remains unclear. A comprehensive evaluation of the efficacy and safety of each intervention is needed to inform clinical decision-making. This study aimed at assessing the efficacy and safety of different interventions for LPS.

METHODS

PubMed, Embase, ScienceDirect, ClinicalKey, Cochrane Library, ProQuest, Web of Science, and ClinicalTrials.gov were searched from inception to December 6th 2018. Only randomized controlled trials (RCTs) including the patients treated for LPS were included. The frequentist models of network meta-analysis were used to compare the effect sizes. The primary outcome was stone free rate, and the secondary outcomes were overall complication rate, major complication rate, retreatment rate, and auxiliary procedure rate.

RESULTS

This study included 13 RCTs comprising 1832 participants undergoing 6 different interventions, including RIRS, PCNL, Mini-PCNL, Micro-PCNL, SWL, and conservative observation. PCNL had the best stone free rate (odds ratio [OR] = 3.45, 95% confidence interval [CI] = 1.30-9.12), followed by Mini-PCNL (OR = 2.90, 95% CI = 1.13-7.46). Meta-regression did not find any association of the treatment effect with age, sex, and stone size. Although PCNL tended to exhibit a higher complication rate, the difference of complication rate among various interventions did not achieve a statistical significance. SWL was the less effective and associated with higher retreatment rate compared with PCNL, Mini-PNCL, and RIRS.

CONCLUSIONS

PCNL was associated with the best stone free rate for LPS regardless of age, sex, and stone size. Each treatment achieved a similar complication rate compared with the others. Future large-scale RCTs are warranted to identify the most beneficial management for renal stones at a more complicated location.

Safety and efficacy of Chinese minimally invasive percutaneous nephrolithotomy in the management of renal stones ≤ 2 cm: a single-center experience

Background

The goal for using smaller caliber instruments in PNL was to reduce the access-related complications and to decrease morbidity. The objective of this study was to evaluate the safety and efficacy of Chinese minimally invasive percutaneous nephrolithotomy (MIPNL) in the treatment of renal stones ≤ 20 mm.

Results

Sixty-seven patients completed the study protocol. The mean age was 41.10 ± 13.99 years (range 18–68 years). There were 43 (64%) male and 24 (36%) females. The mean stone size was ranged from 78.5 to 439.6 mm2 (mean ± SD 172.48 ± 69.54 mm2). The overall SFR was (82%). Twelve (18%) needed post-MIPNL auxiliary procedure, in the form of second MIPNL in 3 (4.5%) cases, SWL in 7 (10%), and RIRS in 2 (3%) cases. The intraoperative complication was present in four patients (5%) include bleeding necessitate blood transfusion in one patient (1.5%) and renal collecting system perforation 3 (4.5%). The postoperative complication was urine leakage 5 (7.5) and fever in 6 (9%) of patients.

Conclusion

Chinese MIPNL is safe and effective method for treatment of renal stone ≤ 20 mm size with satisfactory SFR and low complication rate when SWL failed or contraindicated. It is considered a feasible treatment alternative to standard PNL, in the absence of flexible URS or miniature nephroscope.

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

OBJECTIVE

The purpose of this study was to retrospectively assess the efficacy and safety of minimally invasive nephrolithotomy (MPCNL) versus retrograde intrarenal surgery (RIRS) in the management of upper urinary stones.

METHODS

A comprehensive literature review of articles that investigated the efficacy and safety of MPCNL and RIRS was conducted by systematically searching PubMed, EMBASE, and Cochrane Library in March 2019. Two reviewers searched the literature, independently extracted the data and evaluated the quality of the data according to the inclusion and exclusion criteria. A meta-analysis was performed by using Review Manager 5.3 software.

RESULTS

Eight randomized controlled trials (RCTs) involving 725 patients with upper urinary stones were analysed based on the inclusion criteria. While MPCNL has a better clinical efficacy than RIRS with respect to the stone-free rate (SFR) [RR = 1.11, 95% CI (1.05-1.17), p = 0.0005], MPCNL has a higher incidence of haematoma [RR = 3.09, 95% CI (1.44-6.66), p = 0.004] and longer hospitalization time [MD = 0.89 day, 95% CI (0.07-1.72), p = 0.04]. In addition, no significant difference in operative time [MD = 2.46 min, 95% CI (-17.99 to 22.92), p = 0.81] and postoperative pain score [MD = 0.74, 95% CI (-0.45 to 1.94), p = 0.22] were observed between the two methods. Overall, the evidence was insufficient to suggest a statistically significant difference in the adverse event profile for MPCNL compared with RIRS.

CONCLUSIONS

Our data suggest that MPCNL is an effective method for treating upper urinary stones, especially lower calyceal stones that are 1-2 cm in size. Compared to RIRS, MPCNL is associated with a longer hospital stay time and a higher incidence of haematoma. In addition, both methods have proven to be safe. Nevertheless, the findings should be further confirmed through well-designed prospective RCTs with a larger patient series.

Assessment of lower calyceal single-access percutaneous nephrolithotomy for staghorn stones: A single-surgeon and a single-center experience at KAMC, Riyadh

Introduction:

Percutaneous nephrolithotomy (PCNL) is still the mainstay and the treatment of choice for most complex renal stones. The success of PCNL is defined by achieving a stone-free rate (SFR). Lower calyceal access PCNL is established to be the safest percutaneous access to the renal system, but controversy is present when it comes to SFR in comparison to upper calyceal and middle calyceal accesses.

Aim:

We aim to prove that lower calyceal access PCNL is the safest PCNL access and has the same efficacy as upper calyceal access PCNL for staghorn stones.

Methodology:

All lower calyceal access PCNLs done from May 2012 to August 2017 were included in the study. Postoperative complications were reported using the modified Clavien Grading System.

Results:

Sixty-seven patients were included in the study. The mean age was found to be 49.39 years; most (36 [53.73%]) patients were male. The prevalence of diabetes, hypertension, dyslipidemia, and chronic kidney disease was 40.91%, 47.76%, 37.31%, and 20.00%, respectively. The mean hospital stay was 7.9 days; mean operative time was 138.52 min. The mean staghorn stone burden was 476.34 mm². About 80.59% (n = 54) of patients had complete stone resolution after the first session. Only 3 (4.47%) patients had complications and classified as Grade 2 on the modified Clavien Grading System and the remainder were classified as Grade 1, two patients needed postoperative blood transfusion, and one had a renal pelvis perforation.

Conclusion:

When it comes to safety and efficacy, the use of lower calyceal single-access PCNL has a very low complication rate compared to upper calyceal access PCNL, especially pneumothorax and bleeding.

Retrograde intrarenal surgery vs miniaturized percutaneous nephrolithotomy to treat lower pole renal stones 1.5-2.5 cm in diameter

AIM

To compare the outcomes of retrograde intrarenal surgery (RIRS) and miniaturized percutaneous nephrolithotomy (mini-PCNL) in treating lower pole (LP) renal stones with a diameter of 1.5-2.5 cm.

METHODS

A total of 216 patients who underwent mini-PCNL (n = 103) or RIRS n = 113) for LP stones with a diameter of 1.5-2.5 cm were enrolled between December 2015 and April 2017 at the Urology Department of Ningbo Urology and Nephrology Hospital.

RESULTS

Significant differences were found in the hospital stay (9.39 ± 4.01 vs 14.08 ± 5.26, P < 0.0001) and hospitalization costs (2624.5 ± 513.36 vs 3255.2 ± 976.5, P < 0.0001) between the RIRS and mini-PCNL groups. The mean operation time was not significantly different between the RIRS group (56.48 ± 24.77) and the mini-PCNL group (60.04 ± 30.38, P = 0.345). The stone-free rates at the first postoperative day (RIRS vs mini-PCNL: 90.2% vs 93.2%, P = 0.822) and the second month postoperatively (RIRS vs mini-PCNL: 93.8% vs 95.1%, P = 0.986) were not significantly different.

CONCLUSION

RIRS and mini-PCNL are both safe and effective methods for treating LP stones with a diameter of 1.5-2.5 cm. RIRS can be considered as an alternative to PCNL for the treatment for LP stones of 1.5-2.5 cm.

Research progress of percutaneous nephrolithotomy

Percutaneous nephrolithotomy (PCNL) is generally accepted as the gold standard treatment for the treatment of large kidney stones (> 2 cm). For nearly 40 years, with the continuous progress of technology and the constant updating of ideas, PCNL has made great progress. In this review, we discuss the current research progress, recent advancement and hot spot of the whole process of PCNL including anesthesia, position, puncture, dilation, lithotripsy approaches, perfusate, tube placement, hospitalization time, drug, treatment of residual stones, prognosis judgment and operation evaluation by summarizing the related research in this article.