Miniperc: what is its current status?

Comparative efficacy between retrograde intrarenal surgery with vacuum-assisted ureteral access sheath and minimally invasive percutaneous nephrolithotomy for 1-2 cm infectious upper ureteral stones: a prospective, randomized controlled study

Objective

To observe the efficacy and safety of retrograde intrarenal surgery combined with vacuum-assisted ureteral access sheath (V-UAS) and minimally invasive percutaneous nephrolithotomy (MPCNL) in patients with 1-2 cm infectious upper ureteral stone.

Patients and methods

A total of 173 patients with 1-2 cm infectious upper ureteral stone were prospectively randomized into two groups. Eighty-six in the V-UAS group and 87 cases as control in the MPCNL group. The SFRs at different times (Postoperative 1 day, 2nd week and 4th week) was considered as the primary outcome of the study. The secondary end points were operative time, postoperative hospital stay and operative complications.

Results

There was no obvious difference between two groups in patients' demographics and preoperative clinical characteristics (all P > 0.05). Postoperative data showed that the SFR at postoperative 1 day in the V-UAS group was significantly lower than that in the MPCNL group (73.2% vs. 86.2%, P = 0.034). However, there was no statistical significance between two groups in SFRs during postoperative 2 weeks and 4 weeks (All P > 0.05). The levels of WBC, CRP and PCT were all significant lower in the V-UAS group than those in the MPCNL group at the postoperative 24 h and 48 h (all P < 0.05). Postoperative complications included fever (≥38.5°C), bleeding, pain and urosepsis. In terms of the rates of fever, pain and urosepsis, MPCNL group were all significantly higher than those in the V-UAS group (10.3 vs. 2.4%, P = 0.031; 14.9 vs. 2.4%, P = 0.003; 4.6 vs. 0.0%, P = 0.044; respectively). No significant difference was found between two groups in bleeding. Meanwhile, postoperative hospital stay in the V-UAS group was more shorten than that in the MPCNL group (3.7 vs. 5.9 days, P < 0.001).

Conclusions

Our study showed that RIRS with V-UAS, a new partnership to treat 1-2 cm infectious upper ureteral stones, was satisfying as it achieved a high SFR rate and a low rate of infectious complications. This method was safe and reproducible in clinical practice.

Single-center experience of micro-perc in the treatment of children with 1.0-2.0 cm sized kidney stones in the Galdakao-modified supine Valdivia position

OBJECTIVE

We aimed to explore the applicability and safety of micro-percutaneous nephrolithotomy (micro-perc) in the treatment of children with kidney stones in the Galdakao-modified supine Valdivia (GMSV) position under the guidance of whole-course ultrasound.

MATERIALS AND METHODS

Patients were aged < 18 years in the GMSV position who underwent micro-perc for kidney stones under ultrasound guidance between August 2020 and May 2022 at our institution were reviewed retrospectively.

RESULTS

A total of 23 patients, 15 males and 8 females, received micro-perc. The average stone size was 1.6 cm (range 1.1-2.0 cm). Among them, 12 patients had left kidney stones, 10 patients had right kidney stones, and 1 patient had bilateral kidney stones. The mean operative time was 55.3 min (range 35-86 min). The mean hospital stay was 2.9 days (range 2-4 days). The mean hemoglobin decrease was 1.7 g/L (range 0.9-3.2 g/L). A total of 17 patients had complete stone clearance at 48 h postoperatively. A total of 22 patients had complete stone clearance at 2 weeks postoperatively.

CONCLUSION

Our results demonstrate that micro-perc under ultrasound guidance is a safe and effective method for the treatment of children with kidney stones in the GMSV position. Further research is warranted to confirm these results.

Comparison Between Percutaneous Nephrolithotomy and Retrograde Flexible Nephrolithotripsy in Obese Patients with 2 - 4 cm Renal Stones

Background: Nowadays, because of remarkable advancements in retrograde intrarenal surgery (RIRS), modest attention toward this procedure as the second or alternative choice for renal stones treatment has been drawn. Objectives: In the present study, we compared RIRS and percutaneous nephrolithotomy (PCNL) outcomes in treating obese patients with 2 - 4 cm renal stones. Methods: Eighty-two patients who underwent PCNL (n = 40) and RIRS (n = 42) between June 2015 and December 2018 at the Department of Urology of Sina Hospital were enrolled in our retrospective cohort study. Results: After the first surgery session, stone-free rates for the RIRS group were 92.9% and for the PCNL group was 95% (P value = 0.52). The mean operation time for the RIRS and PCNL groups were 71.6 ± 11 and 93.3 ± 12.2, respectively (P < 0.001). The hospitalization stay for all of the PCNL group was more than 1 day (mean = 2.5 days); however, that for the majority of the RIRS group was less than 1 day (P < 0.001). The analgesic use in the RIRS group was significantly lower than in the PCNL group (9.0 ± 5.5, 61.8 ± 13.6, respectively; P < 0.001). The overall complication rates were higher in the RIRS group. However, none of them were statically significant (P > 0.05). Conclusions: According to satisfactory outcomes obtained in the RIRS groups, it can be concluded that RIRS can be applied as an alternative or even the first choice in obese patients with 2 - 4 cm renal stones.

Mini-Percutaneous Nephrolithotomy With an Endoscopic Surgical Monitoring System for the Management of Renal Stones: A Retrospective Evaluation

Purpose

To compare the outcomes and postoperative quality of life of patients with renal calculi who underwent standard percutaneous nephrolithotomy (sPNL), mini-invasive percutaneous nephrolithotomy (mPNL) or mPNL with an endoscopic surgical monitoring system (ESMS) using a retrospective clinical trial.

Methods

Eighty-six adult patients with renal stones who were treated with sPNL were retrospectively compared to ninety-two patients who were treated with mPNL between July 2014 and December 2017. Next, further studies were retrospectively conducted using a matched paired method. The ninety-two patients treated with mPNL were divided into two groups based on whether the endoscopic surgical monitoring system (ESMS) was used (ESMS-mPNL vs. non-ESMS-mPNL). The ESMS used strain gauge transducers to measure the inflow and outflow of irrigation solution. Bleeding and fluid absorption during endoscopic surgery could be accurately calculated by computer program in ESMS.

Results

The fluoroscopy time, complication rate, stone-free status and clinically insignificant residual fragment (CIRF) rate were not significantly different between the two groups (sPNL vs. mPNL). The mPNL group had a significantly longer operation time than the sPNL group, and the mPNL group exhibited a markedly reduced 12-h postoperative visual analogue pain scale (VAS) score, mean hospitalization time, and return to work time, had slightly reduced haemoglobin loss, and underwent more tubeless operations. Moreover, among the 92 patients who underwent mPNL, the operation time (P = 0.090), complication rate (P = 0.996), stone-free status (P = 0.731), CIRF rates (P = 0.125) and number of tubeless operations (P = 0.760) were not significantly different between the two subgroups (non-ESMS-mPNL vs. ESMS-mPNL); however, the patients in the ESMS-mPNL group had significantly longer irrigation times than those in the non-ESMS-mPNL subgroup, along with marked reductions in irrigation fluid, blood loss, haemoglobin loss, 12 h postoperative VAS score, mean hospitalization time, and return to work time.

Conclusions

mPNL is less painful than sPNL in patients undergoing treatment for 20–40 mm renal stones. Similar stone-free rates were achieved by the two procedures, but mPNL was superior to sPNL in terms of blood loss, discomfort, hospitalization time and return to work time. We think that ESMS-mPNL is less painful for patients and more efficacious than non-ESMS-mPNL, and ESMS-mPNL achieves a stone-free rate that is similar to non-ESMS-mPNL in patients receiving treatment for 20–40 mm kidney stones.

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.

Comparison of vacuum-assisted sheaths and normal sheaths in minimally invasive percutaneous nephrolithotomy: a systematic review and meta-analysis

BACKGROUND

A systematic review and meta-analysis was conducted to compare the safety and efficacy of vacuum-assisted sheaths and conventional sheaths in minimally invasive percutaneous nephrolithotomy (MPCNL) in the treatment of nephrolithiasis.

METHODS

PubMed, Web of Science, Embase, EBSCO, and Cochrane Library databases (updated March 2021) were used to search for studies assessing the effect of vacuum-assisted sheaths in patients who underwent MPCNL. The search strategy and study selection processes were implemented in accordance with the PRISMA statement.

RESULT

Three randomized controlled trials and two case-controlled trials that satisfied the inclusion criteria were enrolled in this meta-analysis. Overall, the stone-free rate (SFR) in patients who underwent vacuum-assisted sheaths was significantly higher than that in patients who underwent conventional sheaths (RR 1.23, 95% CI 1.04, 1.46, P = 0.02), with significant heterogeneity among the studies (I² = 72%, P = 0.03). In terms of the outcome of complications, vacuum-assisted sheath could bring a benefit to the postoperative infection rate (RR 0.48, 95% CI 0.33, 0.70, P < 0.00001) with insignificant heterogeneity among the studies (I² = 0%, P = 0.68). There was no significant difference in the blood transfusion rate (RR 0.35, 95% CI 0.07, 1.73, P = 0.17), with significant heterogeneity (I² = 66%, P = 0.35). Three studies contained operative time data, and the results indicated that the vacuum-assisted sheath led to a shorter operative time (MD = - 15.74; 95% CI - 1944, - 12.04, P < 0.00001) with insignificant heterogeneity (I² = 0%, P = 0.91).

CONCLUSION

The application of a vacuum-assisted sheath in MPCNL improves the safety and efficiency compared to the conventional sheath. A vacuum-assisted sheath significantly increases the SFR while reducing operative time and postoperative infection.

Intraoperative and postoperative surgical complications after ureteroscopy, retrograde intrarenal surgery, and percutaneous nephrolithotomy: a systematic review

INTRODUCTION

Retrograde ureteroscopy (URS), intra-renal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) represent routine interventions for the treatment of ureteral and renal stones, although at times associated with serious adverse events. Of note, the evidence on perioperative complications after these procedures remains sparse and controversial. Moreover, there is a lack of standardized reporting of adverse events using uniform systems. The aim of the present study was to systematically review of the available evidence on URS/RIRS and PCNL for the surgical treatment of urinary stone, assessing the incidence of intra- and postoperative events, classified according to the modified Clavien-Dindo scale.

EVIDENCE ACQUISITION

A systematic review of the literature was performed according to PRISMA recommendations and was conducted on intra- and postoperative complications, as well as on their management, following URS, RIRS and PCNL procedures, particularly focusing on major events.

EVIDENCE SYNTHESIS

Overall, 26 studies (13 on URS/RIRS and 11 on PCNL) met the inclusion criteria and were evaluated. The highest intraoperative complication rate was 11.5% and 8.5% for RIRS and PCNL, respectively. Major complication rate following URS/RIRS and PCNL ranged between 0.3-31.7% and 2-17.1%, respectively. The most frequent adverse events were obstructive pyelonephritis or urinary leakage requiring the placement of a double J stent or a drainage. Among PCNLs series, life-threatening adverse events have also been reported, including bleeding requiring renal angioembolization and urothorax.

CONCLUSIONS

Despite the inclusion of series using a standardized reporting system, the complication rate after URS/RIRS/PCNL remains extensively heterogeneous in the literature; in addition, a non-negligible proportion of studies did not characterize the adverse events nor report the actual management strategy to solve them. Future research is needed to standardize the classification and reporting of surgical complications after endourological procedures (taking into consideration the surgeon's experience and skills), aiming to improve patient counseling and potentially the strategy for their prevention.

A systematic review and meta-analysis of minimally invasive vs. standard percutaneous nephrolithotomy in the surgical management of renal stones

The present study aimed to assess current evidence on the effectiveness and safety of minimally invasive vs. standard percutaneous nephrolithotomy (PCNL) in the management of renal stones. A systematic search of electronic databases, which included PubMed, EMBASE and the Cochrane Library up to May 2019 was performed. Using Review Manager statistical software (version 5.3), primary outcomes, including stone-free rates (SFRs), were evaluated. Meanwhile, analysis was also performed to compare secondary outcomes, such as peri- and postoperative complications and operative data. Fourteen studies involving 1,611 patients with renal stones were analyzed based on the inclusion criteria. On the basis of the present analysis, mini percutaneous nephrolithotomy (MPCNL) was proven to have non-inferior clinical efficacy with respect to the SFR compared with PCNL [odds ratio (OR)=1.10; 95% confidence interval (CI), 0.84-1.44; P=0.48]. In addition, the meta-analysis showed that MPCNL had a significantly lower hemoglobin decrease [mean difference (MD)=-0.68; 95% CI, -1.05 to -0.31; P=0.0003] and fewer blood transfusions (OR=0.36; 95% CI, 0.18-0.71; P=0.003) compared with PCNL. Moreover, the MPCNL group had a shorter inpatient stay (MD=-0.81; 95% CI, -1.55 to -0.08; P=0.03) compared with the PCNL group. However, the overall evidence was insufficient to suggest a statistically significant difference in the adverse event profile for MPCNL compared with PCNL. The present meta-analysis indicates that MPCNL is an effective method for treating renal stones. Compared with PCNL, MPCNL not only has similarly high SFRs but is also associated with less blood loss, fewer blood transfusions, more favorable recovery time and shorter inpatient stays. However, the findings of the present study should be further confirmed by well-designed prospective randomized controlled trials with a larger patient series.

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.

The "all-seeing needle" micro-PCNL versus flexible ureterorenoscopy for lower calyceal stones of ≤ 2 cm

The objectives of the study are to compare the safety and efficacy of "all-seeing needle" optical puncture system micro-percutaneous nephrolithotomy (micro-PCNL) and flexible ureterorenoscopy (FURS) for the treatment of lower calyceal stones of ≤ 2 cm and to determine the advantages and disadvantages of each. 116 patients in total with lower calyceal stones of ≤ 2 cm were randomly divided into two equal groups, "all-seeing needle" optical puncture system micro-PCNL and FURS. In both groups, holmium laser was utilized for lithotripsy. The perioperative parameters were compared between the two groups. Compared to the "all-seeing needle" micro-PCNL group, the mean operative time was significantly longer in the FURS group (P = 0.000). However, there was no significant difference between the two groups with respect to mean hemoglobin reduction (P = 0.087), complications (P = 0.731) and LOS (P = 0.856). The overall SFR of the "all-seeing needle" micro-PCNL group and FURS group was 84.5% (49/58) and 79.3% (46/58), respectively, without any significant difference between the groups (P = 0.469). For treating lower calyceal stones of ≤ 2 cm, the "all-seeing needle" micro-PCNL group had shorter operative time than FURS, while no significant differences between the two groups with respect to mean hemoglobin reduction, complications, LOS and SFR were found.

Evaluation of the effect of Bernoulli maneuver on operative time during mini-percutaneous nephrolithotomy: A prospective randomized study

PURPOSE

To evaluate the effect of 'Bernoulli maneuver' (bringing the access sheath to horizontal plane) on operative time and stone free rates in patients undergoing mini-percutaneous nephrolithotomy (PCNL).

MATERIALS AND METHODS

All consecutive patients with a solitary kidney stone undergoing a mini-PCNL between 2015 and 2016 were included into this study. Patients were randomized either to standard prone or control (C) group patients or to tilted prone with 'Bernoulli maneuver' group (B) patients. Pre-, intra-, and postoperative characteristics of these 2 groups were recorded and analyzed.

RESULTS

A total of 67 patients were included in the study. Of these, 40 patients were randomized to group C and 27 to group B. The mean (95% confidence limits) stone size (mm) in group C and B was 14 (13, 15) and 13 (11, 14), respectively (p=0.26). Nephroscopy time was shorter in Bernoulli group (35 minutes vs. 23 minutes, p=1.5·10^-5, and Bayes factor BF₁₀=2,340, and Cohen standardized effect size d_st=1.2). The difference made it up 12 minutes (with 95% confidence interval from 8 to 18 minutes). There were no statistically significant differences between groups regarding white blood cell, creatinine level and stone-free status defined by computed tomography on the first postoperative day.

CONCLUSIONS

In our study the 'Bernoulli maneuver' led to a shorter nephroscopy time in mini-PCNL. This maneuver can significantly reduce nephroscopy time and save significant amount of operative time, especially in tertiary referral centers with high-volume mini-PCNL procedures.

Miniperc vs Shockwave Lithotripsy for Average-Sized, Radiopaque Lower Pole Calculi: A Prospective Randomized Study

Introduction: To detect safety and feasibility of miniperc and extracorporeal shockwave lithotripsy (SWL) for treatment of average-sized (1-2 cm), radiopaque lower pole calculi in a prospective randomized manner. Patients and Methods: In the period from January 2014 to June 2015, 150 patients were attached to this study with single lower pole radiopaque stone ranging from 10 to 20 mm. Patients were divided randomly into two groups using computer-generated randomization in an equal manner. First group patients were subjected to miniperc procedure, while second group patients underwent SWL. Patient's characters, stones' characters, fluoroscopic time, operative time, blood transfusion, hospital stay, retreatment, auxiliary procedure (AP), and complications using modified Clavien grading are tabulated and analyzed. Results: This study included two equal groups with 75 patients in each group. With regard to age (37.75 ± 11.25 vs 40.55 ± 10.55), body mass index (26.92 ± 2.26 vs 27.29 ± 2.87), and stone size (1.55 ± 0.28 vs 1.57 ± 0.26), there was no significant statistical difference in both groups. Stone-free rate (SFR) (76% vs 96%), operative time (44.81 ± 7.06 vs 93.37 ± 12.29 minutes), fluoroscopy time (53 ± 2.45 vs 180 ± 7.31 seconds), hospital stay (5.72 ± 1.01 vs 45.19 ± 8.48 hour), and blood transfusion were significantly more in the miniperc group. Retreatment rate (45.3% vs 2.7%) and AP (24% vs 4%) were significantly greater in the SWL group. Conclusion: SWL is less invasive than percutaneous stone removal, but it is also less effective for lower pole radiopaque calculi. Miniperc has better SFR and lower auxiliary and retreatment rates; however, it resulted in more drawbacks.

Micropercutaneous nephrolithotripsy: initial experience

INTRODUCTION

For small renal calculi (< 2 cm) the currently available treatment options include extracorporeal shockwave lithotripsy (ESWL), retrograde intrarenal surgery (RIRS) and standard/mini percutaneous nephrolithotomy (PNL). A new method, microperc, has therefore been developed, in which a smaller tract size and smaller instruments were used.

AIM

To present our clinical experiences with micropercutaneous nephrolithotripsy (microperc) in the treatment of small renal calculi.

MATERIAL AND METHODS

We retrospectively evaluated patients with small renal calculi who underwent microperc between February and June 2013. A 4.8 Fr 'all-seeing needle' was used to achieve percutaneous renal access with the C-arm fluoroscopy guidance in the prone position. Holmium: YAG laser 272 µm fiber was used for stone fragmentation.

RESULTS

A total of 20 patients underwent the microperc procedure. The mean age of the patients was 46.5 ±13.8 years. The mean stone size was 13 ±3 mm. The stone-free rate (SFR) was 90% (18/20). Two patients had clinically significant residual fragments (≥ 4 mm). The mean operation and fluoroscopy times were 107.5 ±37 min and 45 ±40 s respectively. The mean postoperative drop in hemoglobin was 1.2 ±0.9 g/dl, and 1 patient required blood transfusion. The patients were discharged after an average hospitalization of 1.4 ±0.8 days. Two complications, urinary tract infection and blood loss requiring blood transfusion, were observed in 2 patients postoperatively.

CONCLUSIONS

We suggest that microperc should be considered for the treatment of small renal stones.

Mini-percutaneous Nephrolithotomy vs Retrograde Intrarenal Surgery for Renal Stones Larger Than 10 mm: A Prospective Randomized Controlled Trial

OBJECTIVE

To compare miniaturized percutaneous nephrolithotomy (mini-PCNL) and retrograde intrarenal surgery (RIRS) in the management of renal stones >10 mm in a single session.

METHODS

Seventy patients presenting with renal stones >10 mm were randomized to a mini-PCNL or an RIRS group in a ratio of 1:1. Randomization was performed by a biostatistician and opened to the surgeon at the time of the patient's admission on the day before surgery. Patient and stone characteristics, perioperative outcomes, and complications were compared between the 2 groups. The primary end point of "stone-free" which was defined as no residual stone or stones <2 mm on computed tomography within 3 months postoperatively.

RESULTS

Thirty-five patients (mini-PCNL) and 33 (RIRS) were included in the final analysis. Mini-PCNL and RIRS had a stone-free rate of 85.7% and 97.0%, respectively (P = .199). Operation time (P = .148), hemoglobin decline (P = .323), and hospital stay (P = .728) were similar between the 2 groups. Pain visual analog score at 1 hour postoperatively (P = .029) and analgesic requirement (P = .050) were higher in the RIRS group. Two patients in the mini-PCNL group and 1 in the RIRS group had minor pelvic or ureter perforation. One patient in each of the 2 groups had hypertension and urinary tract infection.

CONCLUSION

Mini-PCNL and RIRS are safe and feasible surgical options to manage renal stones >10 mm. RIRS produced a slightly higher stone-free rate, but more immediate postoperative pain and higher analgesic requirement compared with mini-PCNL.

Minimally invasive versus standard percutaneous nephrolithotomy: a meta-analysis

The aim of the study was to objectively analyze the outcomes for minimally invasive percutaneous nephrolithotomy (MPCNL) vs standard percutaneous nephrolithotomy (PCNL) by systematic review and meta-analysis of published data. A systematic literature review was performed in November 2014 using the PUBMED, EMBASE and Cochrane Library databases to identify relevant studies. Only comparative studies investigating MPCNL vs PCNL were included. Effect sizes were estimated by pooled odds ratio (ORs) and mean differences (MDs). The analyzed outcomes were stone-free rate (SFR), blood loss, pain assessment, operative time, hospital stay and complications. We identified 8 trials with a total 749 patients. 353 patients were treated with MPCNL and 396 with PCNL. Meta-analysis of the data showed that there was no difference in SFR between MPCNL and PCNL (OR 1.06, 95% CI 0.71-1.58). Patients in the MPCNL group experienced less drop in hemoglobin (MD: -4.67 g/L, 95% CI -7.29 to -2.04), a lower incidence of blood transfusion (OR 0.18, 95% CI 0.06-0.54), less pain (visual analog score) (MD: -0.53, 95% CI -0.94 to -0.13) and shorter hospitalization (MD: -1.32 days, 95% CI -2.15 to -0.50). Operative time was longer in the MPCNL group (MD: 15.54 min, 95% CI 4.25-26.83). Postoperative fever and pyelocalyceal perforation did not differ between the groups (p = 0.38 and 0.44, respectively). Current evidence suggested that MPCNL was a safe and effective procedure with an SFR comparable to that of PCNL. MPCNL resulted in less bleeding, fewer transfusion, less pain and shorter hospitalization. Well-designed multicentric/international randomized, controlled trials are still needed.

Extracorporeal shock wave lithotripsy versus retrograde intrarenal surgery for treatment for renal stones 1-2 cm: a meta-analysis

This study is to evaluate the efficacy and safety of extracorporeal shock wave lithotripsy (ESWL) versus retrograde intrarenal surgery (RIRS) for the treatment for renal calculi 1-2 cm. PubMed, Embase, the Cochrane Central Register of Controlled Trials, and the Chinese Biomedical Literature Database were researched and hand-searched for relevant congress abstracts and journals about RIRS and ESWL for the treatment for 1- to 2-cm renal stones. The retrieval time ended in September 2014. The related trials met the inclusion criteria were included in the meta-analysis. Two reviewers independently assessed the quality of all included studies, and meta-analysis was performed with RevMan 5.2. Seven literatures were retrieved, including 983 patients. The meta-analysis results showed that, compared to RIRS group, the patients in ESWL group had the following features:(1) the stone-free rate [relative risk (RR) 0.86; 95% confidence interval (CI) 0.77-0.95, P = 0.005] was significantly different between two groups; (2) The retreatment rate of RIRS group was lower (RR 8.12; 95% CI 4.77-13.83, P < 0.00); (3) The complications were not significantly different between two groups (Grade I RR 1.06; 95% CI 0.67-1.69, P = 0.80; Grade II RR 0.75; 95% CI 0.29-1.91, P = 0.54; Grade III RR 0.86; 95% CI 0.26-2.86, P = 0.80). Compared to ESWL, our results showed that RIRS provided significantly higher stone-free rate and lower retreatment rate and without increase in the incidence of complications. However, further randomized trials are needed to confirm these findings.

Outcomes in a large series of minipercs: analysis of consecutive 318 patients

BACKGROUND AND PURPOSE

The purpose of this study is to evaluate the outcomes of miniperc at our center.

PATIENTS AND METHODS

This is a retrospective review of consecutive 318 minipercs done in a single tertiary urological center. The Miniperc system used was either Wolf (Richard Wolf) 14F with 20F Amplaz sheath or Storz (Karl Storz) nephroscope 12F with 15/18F sheath or 16.5/19.5F sheath. Data about the demography of patients, comorbidities, stone size, number and size of the tract, size of nephroscope, energy source used, total operative time, exit strategy, hospital stay, clearance of stones, total analgesic requirement, visual analogue pain score at 6 and 24 hours, hemoglobin drop and complications were analyzed by the chi-square test and analysis of variance test.

RESULTS

The average age of patients, stone size, operative time, hemoglobin drop and hospital stay were 41.9±17.0 years, 15.26±6.35 mm, 60±19 minutes,1.0±0.6 g/dL and 2.8±1 day, respectively. Complete clearance rate was 98.7%. Fourteen (4.4%) patients had Clavien-Dindo level 1 complications and 1 (0.31%) patient had Clavien-Dindo level 2 complications. The size of the stone treated by miniperc did not affect the hemoglobin drop (p-value=0.26) or hospital stay (p-value=0.924). There is no significant increase in hemoglobin drop (p-value=0.064) or hospital stay (p-value=0.627) with increasing number of miniperc tracts. An increase in operative time is associated with the increase in hemoglobin drop (p-value=0.041). Different energy sources did not significantly affect the operative time (p-value=0.184). Placement of only ureteral catheter is associated with less analgesic requirement (p-value=0.000).

CONCLUSIONS

Miniperc is a safe alternative to standard percutaneous nephrolithotomy. In carefully selected patients, the best exit strategy would be a tubeless procedure with ureteral catheter drainage.

Percutaneous nephrolithotomy and ureteroscopy in children: evolutions

The increasing incidence of pediatric stone disease has coincided with significant advances in technology and equipment, resulting in drastic improvements in management. Miniaturization of both ureteroscopes and percutaneous nephrolithotomy (PCNL) equipment has facilitated access to the entirety of the urinary tract and has made ureteroscopy a first-line therapy option along with shock-wave lithotripsy for kidney and ureteral stones. Advances in PCNL have decreased patient morbidity while preserving stone clearance rates. In this review, the advances in operative approach for ureteroscopy and PCNL in children and its applicability to current surgical management of pediatric stone disease are discussed.

A prospective, randomized comparison of shock wave lithotripsy, retrograde intrarenal surgery and miniperc for treatment of 1 to 2 cm radiolucent lower calyceal renal calculi: a single center experience

PURPOSE

A prospective, randomized comparison of shock wave lithotripsy, retrograde intrarenal surgery and miniperc for the treatment of 1 to 2 cm radiolucent lower calyceal renal calculi was done to evaluate the safety and efficacy of these procedures.

MATERIALS AND METHODS

Patients with a single 1 to 2 cm radiolucent lower calyceal renal stone who underwent treatment between January 2012 and May 2013 were included in study. They were randomized to shock wave lithotripsy, retrograde intrarenal surgery and miniperc groups. Patient demographic profiles, success and re-treatment rates, auxiliary procedures and complications were analyzed.

RESULTS

A total of 45 patients were enrolled in each of the shock wave lithotripsy, retrograde intrarenal surgery and miniperc groups. Three, 2 and 4 patients, respectively, were excluded from final analysis due to a matrix stone diagnosis. Mean procedure and fluoroscopy times were significantly greater in the miniperc group than in the other groups. Hospital stay (3.1 days vs 3.1 hours and 1.3 days, p = 0.01) and the blood transfusion rate (13.3% vs 0% and 0%, p = 0.03) were significantly higher for miniperc vs shock wave lithotripsy and retrograde intrarenal surgery, respectively. The re-treatment rate (63.4% vs 2.1% and 2.2%, p <0.001) and the auxiliary procedure rate (20.2% vs 8.8% and 6.6%, p = 0.02) were significantly greater for shock wave lithotripsy than for retrograde intrarenal surgery and miniperc, respectively. The 3-month stone-free rate of shock wave lithotripsy, retrograde intrarenal surgery and miniperc was 73.8% (31 of 42 patients), 86.1% (37 of 43) and 95.1% (39 of 41), respectively (p = 0.01).

CONCLUSIONS

Miniperc and retrograde intrarenal surgery were more effective than shock wave lithotripsy to treat 1 to 2 cm radiolucent lower calyceal renal calculi in terms of a better stone-free rate, and lesser auxiliary and re-treatment rates. However, miniperc resulted in more complications, greater operative time and radiation exposure, and a longer hospital stay.