Minimally invasive percutaneous nephrolithotomy with multiple mini tracts in a single session in treating staghorn calculi

International Alliance of Urolithiasis (IAU) guideline on staghorn calculi management

BACKGROUND

The stone burden based management strategy reported in the guidelines published by different associations is well known for a long time. Staghorn calculi, representing the largest burden and most complex stones, is one of the most challenging cases to practicing urologists in clinical practice. The International Alliance of Urolithiasis (IAU) has released a series of guidelines on the management of urolithiasis.

PURPOSE

To develop a series of recommendations for the contemporary management management of staghorn calculi and to provide a clinical framework for urologists treating patients with these complex stones.

METHODS

A comprehensive literature search for articles published in English between 01/01/1976 and 31/12/2022 in the PubMed, OVID, Embase and Medline database is performed. A series of recommendations are developed and individually graded following the review of literature and panel discussion.

RESULTS

The definition, pathogenesis, pathophysiology, preoperative evaluation, intraoperative treatment strategies and procedural advice, early postoperative management, follow up and prevention of stone recurrence are summarized in the present document.

CONCLUSION

A series of recommendations regarding the management of staghorn calculi, along with related commentary and supporting documentation offered in the present guideline is intended to provide a clinical framework for the practicing urologists in the management of staghorn calculi.

A comparison of S.T.O.N.E nephrolithometry scoring system, Guy's stone score, and Seoul National University Renal Stone Complexity (S-ReSC) in predicting mini-PCNL stone-free rate

The main goal of the study is to evaluate the three stone scoring systems (S.T.O.N.E nephrolithometry scoring system (STONE), Guy's stone score (GSS) and Seoul National University Renal Stone Complexity (S-ReSC)) for the stone-free rate (SFR) of mini-PCNL. We retrospectively analyzed 72 patients who received mini-PCNL from February 2018 to October 2020. The SFR, complication rates, hospitalization days and recurrence rates were analyzed using three stone scoring systems. The result showed statistical significance in the association between scoring system and stone-free (STONE: OR 95%CI 0.409 (0.221-0.759), p = 0.0045; S-ReSC OR 95%CI 0.633 (0.401-0.999), p = 0.0497), but not GSS (OR 95%CI 0.776 (0.397-1.516), p = 0.4581). After adjusting the potential confounding factors, the area under curve (AUC) of STONE, GSS, and S-ReSC was 0.86, 0.78, and 0.81, respectively, and Akaike information criterion (AIC) of STONE, GSS, and S-ReSC was 64.65, 74.89, and 69.92, respectively. The accuracy rate of STONE, GSS, and S-ReSC was 0.81, 0.75, and 0.79, respectively. There was no statistically difference of predicting stone recurrence (p = 0.46, 0.53, 0.86), complications (p = 0.74, 0.51, 0.16) and hospitalization days (p = 0.77, 0.86, 0.87) in STONE, GSS, and S-ReSC, respectively. In conclusion, both the STONE and S-ReSC stone scoring systems are viable for predicting the SFR following mini-PCNL, especially after variable adjustment with the STONE system demonstrating superiority over S-ReSC.

Mini-versus standard percutaneous nephrolithotomy in pediatric population: A randomized controlled trial

INTRODUCTION

Mini PCNL has gained popularity in adult patients due to reduction in the complication rate with comparable stone free rate. There is paucity of level 1 evidence regarding the benefit of mini PCNL in the pediatric group.

OBJECTIVE

We performed a randomised study to compare mini PCNL (mPCNL) with standard PCNL (sPCNL) for the management of renal calculi in patients less than 18 years of age in terms of safety, efficacy, and stone-free rate (SFR).

MATERIALS AND METHODS

A randomised controlled trial was performed on 50 children who underwent PCNL from June 2015 to March 2021, who were divided into two groups. Group I had 25 patients managed with mPCNL (sheath size 16.5 Fr) and Group II had 25 patients who underwent sPCNL (sheath size 26 Fr). Primary outcomes including stone free rates (SFR) and hemoglobin drop and secondary outcomes like operative time, complications, pain score, need of analgesia, incidence of nephrostomy site leak, hospital stay in days were compared between the two groups.

RESULTS

The mean age of patients in groups I and II was 9.4 ± 2.6 and 10.4 ± 2.26 years, respectively (p = 0.15). The mean stone sizes in both groups I and II were 18.6 ± 2.56 and 20.2 ± 3.58 mm, respectively (p > 0.05). The stone free rate for group I was 88% and for group II, 92% (p = 0.64). The average drop in hemoglobin was higher in group II compared to group I (1.1 ± 0.31 g/dl and 1.7 ± 0.23 g/dl respectively; p < 0.0001), however the mean blood transfusion rate was not significantly different in both groups. The operating time was shorter in group II compared to group I (p-value - 0.0030). The pain scores were lesser for the group I. Grade I complications were higher in group II as compared to group I (p-0.047); however, grade II complications were comparable in both groups. The mean hospital stay was not significantly different in both groups.

DISCUSSION

This study confirms the role of mini PCNL in pediatric patients with renal stones. The stone clearance rate of mini PCNL is equivalent to standard PCNL, with lesser blood loss and postoperative complications, however with longer operative time during mPCNL. The small number of the participants in both arms is a limitation of this study and may also reflect fewer children with urolithiasis being treated surgically even in a tertiary care referral centre.

CONCLUSIONS

Mini-PCNL offers equivalent stone free outcome with lower complications rate compared to the standard PCNL for all types of renal stones.

Miniaturization in percutaneous nephrolithotomy: What is new?

Objective

To summarize recent advancements in mini-percutaneous nephrolithotomy (mini-PCNL) in surgical technique, stone removal strategy, lithotripsy, and surgical model from the current literature.

Methods

We conducted a narrative review of relevant English-language articles up to October 2022 using the PubMed and Web of Science databases. The following keywords were used in the search: "percutaneous nephrolithotomy", "minimally invasive percutaneous nephrolithotomy", "mini-PCNL", "mini-perc", "mPCNL", and "miniaturization".

Results

A series of new progress has been made in many aspects of mini-PCNL, such as further reduction of tract size-needle perc and further improvement of robotic-assisted PCNL-artificial intelligence-powered robotic devices.

Conclusion

Many studies and trials have been conducted to reduce morbidity and increase the safety and effectiveness of mini-PCNL. It is crucial to realize that miniaturization of PCNL requires not only a smaller percutaneous tract size, but also an adjustment strategically in renal access, stone removal, lithotripsy, and surgical model in general. More large-scale prospective research needs to be carried out to further validate and optimize the safety and effectiveness of mini-PCNL.

Comparison of postoperative outcomes of mini percutaneous nephrolithotomy and standard percutaneous nephrolithotomy: a meta-analysis

Our study was aimed to evaluate the postoperative outcomes of Mini Percutaneous Nephrolithotomy (Mini-PCNL) and Standard Percutaneous Nephrolithotomy (Standard-PCNL) to determine the optimum option for patients with renal calculi. For publications published between January 2010 and April 2021, a comprehensive search of the PubMed, Cochrane Library, Web of Science, and EMBASE databases was done. The literatures were chosen based on the criteria for inclusion and exclusion. After the data were retrieved and the quality was assessed, the meta-analysis was performed using Review Manager Software (RevMan 5.4.1, Cochrane Collaboration, Oxford, UK). We selected 20 trials with a total of 4953 people out of 322 studies. There were 2567 patients treated with Mini-PCNL and 2386 patients treated with Standard-PCNL. Meta-analysis results showed no difference in stone-free rates (SFR, P = 0.93), fever (P = 0.83), and postoperative pain (VAS score) (P = 0.21) between Mini-PCNL and Standard-PCNL. Patients in the Mini-PCNL group experienced shorter hospital stay (P < 0.0001), less hemoglobin drop (P < 0.00001), less blood transfusion (P < 0.00001), higher postoperative tubeless (P = 0.0002), and fewer complications including bleeding (P = 0.01), perforation (P = 0.03), and leakage (P = 0.01). Compared with Standard-PCNL, operative time was longer in the Mini-PCNL group (P = 0.0005). Mini-PCNL had a shorter hospital stay, less hemoglobin drop, less blood transfusion, greater postoperative tubeless, fewer complications, and a longer operational time when compared to Standard-PCNL. SFR, fever, and postoperative pain were similar in both of them. Mini-PCNL may be a superior option for patients with proper size renal calculi.

Mini Versus Standard Percutaneous Nephrolithotomy for the Management of Renal Stone Disease: Systematic Review and Meta-analysis of Randomized Controlled Trials

CONTEXT

Mini percutaneous nephrolithotomy (mPNL) involves the creation of a smaller access tract compared with standard PNL (sPNL). Smaller tract sizes could lead to decreased blood loss, pain, and need for blood transfusion. Previous studies on this topic have reported variable findings and were of poor quality.

OBJECTIVE

To compare the safety and efficacy of mPNL with those of sPNL for the management of patients with renal stone disease by conducting a systematic review and meta-analysis.

EVIDENCE ACQUISITION

Systematic literature search was performed to identify relevant randomized controlled trials (RCTs) for the review. The primary outcomes for the study were stone-free rate (SFR) and blood transfusion rate. The secondary outcomes were complication rates, fever, fall in hemoglobin, operative time, length of stay (LOS), need for auxiliary procedure, and visual analog scale (VAS) score at 24 h. We followed Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines, and the study protocol was registered with PROSPERO in priori (CRD42021252444).

EVIDENCE SYNTHESIS

In this review, 16 RCTs with 3961 patients were included. SFR was comparable between the two groups (risk ratio [RR] 1.01 [0.99, 1.04], p = 0.30), whereas the need for transfusion was lower with mPNL (RR 0.54 [0.37, 0.78], p = 0.001). Fall in hemoglobin (mean difference [MD] -0.67 [-0.93, -0.41], p = 0.000) and LOS (MD -0.59 [-0.81, -0.37], p = 0.000) were shorter with mPNL. Operative time was significantly shorter with sPNL (MD 8.28 [3.96, 12.59], p = 0.000). Complications were lower with mPNL (RR 0.89 [0.79, 0.97], p = 0.01). The need for auxiliary procedures (RR 0.77 [0.58, 1.03], p = 0.08) and VAS at 24 h (MD -0.79 [-1.63, 0.05], p = 0.06) were similar in the two groups.

CONCLUSIONS

Mini PNL has similar efficacy to sPNL in terms of SFRs. However, mPNL has a superior safety profile with fewer overall complications and a reduced need for blood transfusion.

PATIENT SUMMARY

In this study, we conducted a meta-analysis comparing mini and standard percutaneous nephrolithotomy (PNL) for the management of patients with renal stone disease. We showed that mini and standard PNL are associated with similar stone-free rates. Overall complications and the need for blood transfusion were lower with mini PNL.

Is There Still a Place for Percutaneous Nephrolithotomy in Current Times?

Background: Percutaneous nephrolithotomy (PCNL) and its miniaturized modifications are usually considered the standard surgical options for large (>20 mm) staghorn and infected stones. Moreover, PCNL is a viable alternative to retrograde intrarenal surgery (RIRS) for smaller stones (<20 mm) in the presence of anatomical malformations or inaccessible lower pole stones. However, due to the advancements in laser and scope technology, RIRS is expanding its indications with the potential benefits of lower complications and a shorter hospital stay. Methods: A literature search using the PUBMED database from inception to June 2022 was performed to explore the current role of PCNL in endourology. The analysis involved a narrative synthesis. Results: PCNL confirmed its role in the treatment of large and complex stones; moreover, miniaturized PCNL has become more competitive, gaining space among classic indications of flexible ureteroscopy. Conclusions: considering all the evaluated subgroups, we can conclude that PCNL is an old fascinating procedure and is here to stay.

One-stage efficacy of single tract minimally invasive ECIRS in the improved prone frog split-leg position for staghorn stones

OBJECTIVE

To explore the feasibility, safety, and effectiveness of single tract minimally invasive endoscopic combined intrarenal surgery (stmECIRS) in the improved prone frog split-leg position for staghorn stones.

METHOD

A total of 83 patients with staghorn stones were retrospectively reviewed between January 2018 and June 2021. According to surgical procedure and position, patients were divided into a group of single tract minimally invasive percutaneous nephroscopy (stmPNL) in the prone position and a group of stmECIRS in the improved prone frog split-leg position (turned to the prone position after preset the flexible ureteroscope sheath in lithotomy position, meanwhile, bend both hips and knees to be frog abduction). Demographic characteristics, laboratory tests, stone characters, surgical information, stone-free rate (SFR), and perioperative complications were observed and analyzed.

RESULTS

There were no significant differences in demographic characteristics, changes level of Scr and Hb, stone size, radiation density, length of hospital stay, and operation time between the two groups. One-stage SFR in the stmECIRS group was significantly higher than that in the stmPNL group (84.4% vs. 57.9%) (P = 0.007), only 2 patients required blood transfusion after surgery (P = 0.862), and other postoperative complications were not statistically significant (P = 0.345).

CONCLUSIONS

StmECIRS in improved prone frog split-leg position has a higher one-stage SFR than stmPNL for staghorn renal stones, and without complications increased, which is a safe, efficient and feasible treatment.

Mini Percutaneous Kidney Stone Removal: Applicable Technologies

Percutaneous nephrolithotomy (PCNL) remains the treatment of choice for large and complex renal stones. The technological advances over the past several decades gave birth to different varieties of minimally invasive PCNLs, including the mini-PCNL, ultra-mini PCNL, super mini-PCNL, and micro-PCNL, with indications being extended to stones even larger than 20 mm. This article provides an update of all these available techniques of miniaturized PCNL along with its anatomic and physiologic impact. This should assist urologists in providing a personalized approach to the patient based on various patient- and stone-related factors to provide the best of all available technology for treatment.

Pooled-analysis of efficacy and safety of minimally invasive versus standard percutaneous nephrolithotomy

BACKGROUND

This study aimed to assess the efficacy and safety of minimally invasive percutaneous nephrolithotomy (MPCNL) versus standard percutaneous nephrolithotomy in patients with renal and upper ureteric stones.

METHODS

We conducted a pooled analysis on randomized controlled trials (RCTs). The eligible RCTs were selected from the following databases: MEDLINE, Embase, Web of Science, and the Cochrane Library. The reference lists of retrieved studies were also investigated.

RESULTS

Our analysis included 10 RCTs with 1612 patients. Pooled data from 10 RCTs revealed the following: stone-free rate (odds ratio = 1.46, 95% confidence interval (CI) [1.12,1.88], P = .004), operative time (mean difference [MD]  = 4.10, 95% CI [-1.37,9.56], P = .14), length of hospital stay (MD = -15.31, 95% CI [-29.43,-1.19], P = .03), hemoglobin decrease (MD = -0.86, 95% CI [-1.19,-0.53], P < .00001), postoperative fever (MD = 0.83, 95% CI [0.49,1.40], P = .49), and urine leakage (MD = 0.59, 95% CI [0.25,1.37], P = .22). Besides, we performed sub-group analysis based on vacuum suction effect and multiple kidney stones. For vacuum suction effect, it revealed the following: stone-free rate in vacuum suction group (P = .007) and in non-vacuum suction group (P = .19). Operative time in vacuum suction group (P = .89), non-vacuum suction group (P = .16). Postoperative fever in vacuum suction group (P = .49), non-vacuum suction group (P = .85).

CONCLUSION

This pooled analysis indicated that MPCNL was a safe and effective method for treating renal stones compared with standard percutaneous nephrolithotomy. Besides, the vacuum suction effect in MPCNL played a more important role. When it comes to multiple or staghorn stones, the longer operative time in MPCNL could not be ignored.

European Association of Urology Section of Urolithiasis and International Alliance of Urolithiasis Joint Consensus on Percutaneous Nephrolithotomy

CONTEXT

Although percutaneous nephrolithotomy (PCNL) has been performed for decades and has gone through many refinements, there are still concerns regarding its more widespread utilization because of the long learning curve and the potential risk of severe complications. Many technical details are not included in the guidelines because of their nature and research protocol.

OBJECTIVE

To achieve an expert consensus viewpoint on PCNL indications, preoperative patient preparation, surgical strategy, management and prevention of severe complications, postoperative management, and follow-up.

EVIDENCE ACQUISITION

An international panel of experts from the Urolithiasis Section of the European Association of Urology, International Alliance of Urolithiasis, and other urology associations was enrolled, and a prospectively conducted study, incorporating literature review, discussion on research gaps (RGs), and questionnaires and following data analysis, was performed to reach a consensus on PCNL.

EVIDENCE SYNTHESIS

The expert panel consisted of 36 specialists in PCNL from 20 countries all around the world. A consensus on PCNL was developed. The expert panel was not as large as expected, and the discussion on RGs did not bring in more supportive evidence in the present consensus.

CONCLUSIONS

Adequate preoperative preparation, especially elimination of urinary tract infection prior to PCNL, accurate puncture with guidance of fluoroscopy and/or ultrasonography or a combination, keeping a low intrarenal pressure, and shortening of operation time during PCNL are important technical requirements to ensure safety and efficiency in PCNL.

PATIENT SUMMARY

Percutaneous nephrolithotomy (PCNL) has been a well-established procedure for the management of upper urinary tract stones. However, according to an expert panel consensus, core technical aspects, as well as the urologist's experience, are critical to the safety and effectiveness of PCNL.

Does Miniaturization Actually Decrease Bleeding After Percutaneous Nephrolithotomy? A Single-Center Randomized Trial

Introduction: Miniaturization of percutaneous nephrolithotomy (mPCNL) was proposed to decrease postoperative bleeding, as there is decreased parenchymal injury compared with standard percutaneous nephrolithotomy (SPCNL). Published randomized controlled trials (RCTs) evaluating bleeding after mPCNL have shown conflicting results. Hence, the evidence to say that mPCNL offers less postoperative bleeding is not robust. Materials and Methods: Prospective RCT was done by comparing mPCNL and SPCNL for treatment of renal stones of size 1 to 3 cm. Patients with active urinary tract infection, renal malformation, uncorrected coagulopathy, and raised serum creatinine (>1.5 mg/dL) were excluded. Blood loss was evaluated by measuring fall in hemoglobin and hematocrit on postoperative day 1. Postoperative pain was evaluated by visual analogue scale (VAS) score at 6, 24, and 48 hours. Results: A total of 60 patients (30 in each arm) were enrolled during the study period. All the baseline preoperative variables were comparable in both the groups. The SPCNL group had a significantly higher drop in hematocrit level as compared with mPCNL (4.6 ± 3.1% vs 3.1 ± 2.1%, p = 0.02). The mean fall in hemoglobin was higher in SPCNL as compared with mPCNL (1.61 ± 0.9 gm% vs 1.21 ± 0.7 gm%, p = 0.07), but it was not significant. Blood transfusion (BT) rate was comparable in both the groups (one patient in each group). The mPCNL group had significantly less VAS scores at 6 hours (3.27 ± 1.20 vs 4.40 ± 1.52, p = 0.002) and 24 hours (2.10 ± 0.54 vs 2.83 ± 1.05, p = 0.001) after surgery. Postoperative complications and hospital stay were comparable in both the arms. Conclusion: mPCNL is associated with less postoperative bleeding and pain than SPCNL. However, the small tract size does not prevent against the clinically significant bleeding requiring BT.

Comparison of standard- and mini-percutaneous nephrolithotomy for staghorn stones

Objectives: To compare the outcomes of standard- and mini-percutaneous nephrolithotomy (PCNL) for the treatment of staghorn stones.

Patients and Methods: The data of consecutive adult patients who underwent PCNL for the treatment of staghorn stones, between July 2015 and December 2019 from three hospitals, were retrospectively reviewed. All cases were performed in a prone position under fluoroscopic guidance. The nephrostomy tracts were dilatated to 30 F in standard-PCNL and to 18–20 F in mini-PCNL. Stones were fragmented with pneumatic lithotripsy in both groups. Fragments were removed with forceps in the standard-PCNL, while they were evacuated through the sheath using the vacuum clearance effect in mini-PCNL. A ureteric stent was inserted after mini-PCNL, while a nephrostomy tube was inserted after standard-PCNL.

Results: The study included 153 patients; 70 underwent standard-PCNL and 83 underwent mini-PCNL. The stone-free rates of PCNL monotherapy were comparable for both groups (83% for mini-PCNL and 88.6% for standard-PCNL, P = 0.339). The incidence (12% vs 24.3%, P = 0.048) and severity of complications were significantly lesser with mini-PCNL (P = 0.031). Standard-PCNL was associated with increased rate of blood transfusion (12.9% vs 2.4%, P = 0.013) and a significant decrease in haemoglobin (P = 0.018). Hospital stay was significantly longer for standard-PCNL than mini-PCNL (median stay of 6 vs 3 days, P < 0.001).

Conclusions: The efficacy of mini-PCNL was comparable to standard-PCNL in the treatment of staghorn stones. The advantages of mini-PCNL included a lesser incidence and severity of complications, and shorter hospital stay.

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.

Multitract percutaneous nephrolithotomy in the management of staghorn stones

Background

Staghorn stones are difficult to manage with a risk of significant renal impairment and urosepsis. Percutaneous nephrolithotomy is the first-line treatment for staghorn stones. Often, multiple access tracts are needed to render the patient stone-free. PCNL has been combined with SWL, flexible URS (ECIRS), and mini-PCNL to access residual fragments without the need of additional tracts. However, in a country with limited access to technology and a restraint on resources, multitract PCNL still is the preferred option. The aim of this study was to assess the safety and efficacy of multitract PCNL in such an environment.

Methods

We analyzed data on sixty-five patients with staghorn calculus who underwent multitract PCNL for a staghorn calculus. Data included demographics, stone parameters, intraoperative parameters, complications and clinical outcomes. Hb-drop and creatinine changes were assessed pre- and post-OP. Complications were graded according to the modified Clavien-Dindo classification.

Results

In a total of 65 patients [47 males (72%)], 154 percutaneous access tracts were used in 66 renal units. The number of tracts varied between 2 and 4 in a single renal unit. The stone-free rate was 85%. 20% of patients developed grade I, 14% grade II, and 3% grade III b complications. There were no grade IV and V complications.

Conclusion

Multitract PCNL is safe and efficient, with a good stone-free rate and an acceptable complication rate. When auxiliary combination treatments are not available, multitract standard PCNL remains an option.

Consultation on kidney stones, Copenhagen 2019: lithotripsy in percutaneous nephrolithotomy

PURPOSE

To evaluate the balance between existing evidence and expert opinions on the safety and efficacy of new technological improvements in lithotripsy techniques for percutaneous nephrolithotomy (PCNL).

METHODS

A scoping review approach was applied to search literature in Pubmed, Embase, and Web of Science. Consensus by key opinion leaders was reached at a 2-day meeting entitled "Consultation on Kidney Stones: Aspects of Intracorporeal Lithotripsy" held in Copenhagen, Denmark, in September 2019.

RESULTS

New-generation dual-mode single-probe lithotripsy devices have shown favourable results compared with use of ballistic or ultrasonic lithotripters only. However, ballistic and ultrasonic lithotripters are also highly effective and safe and have been the backbone of PCNL for many years. Compared with standard PCNL, it seems that mini PCNL is associated with fewer bleeding complications and shorter hospital admissions, but also with longer operating room (OR) time and higher intrarenal pressure. Use of laser lithotripsy combined with suction in mini PCNL is a promising alternative that may improve such PCNL by shortening OR times. Furthermore, supine PCNL is a good alternative, especially in cases with complex renal stones and large proximal ureteric stones; in addition, it facilitates endoscopic combined intrarenal surgery (ECIRS).

CONCLUSION

Recent technological improvements in PCNL techniques are promising, but there is a lack of high-level evidence on safety and efficacy. Different techniques suit different types of stones and patients. The evolution of diverse methods has given urologists the possibility of a personalized stone approach, in other words, the right approach for the right patient.

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.

Standard versus Mini-Percutaneous Nephrolithotomy for Renal Stones: A Meta-Analysis

Objective:

To compare the standard percutaneous nephrolithotomy and mini-percutaneous nephrolithotomy in order to determine the optimal tract size for patients with renal stones.

Methods:

A systematic search of Web of Science, EMBASE, Cochrane Library, and PubMed databases was conducted for articles published through 20 August 2019, reporting on a comparison of the standard percutaneous nephrolithotomy and mini-percutaneous nephrolithotomy using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

Results:

Of 763 studies, 14 were considered for the evidence synthesis. A total of 1980 cases were included. Of these patients, 897 cases underwent standard percutaneous nephrolithotomy, and 1083 cases underwent mini-percutaneous nephrolithotomy. Stone-free rates were 87.6% (786 of 897 patients) for standard percutaneous nephrolithotomy and 87.8% (951 of 1083 patients) for mini-percutaneous nephrolithotomy ( p = 0.57). Tract sizes of 30F and 22–26F in standard percutaneous nephrolithotomy group shorten operation time compared with mini-percutaneous nephrolithotomy ( p = 0.02; p = 0.004; respectively). Leakage ( p = 0.04), bleeding ( p = 0.01), blood transfusion ( p < 0.00001), and renal pelvis perforation ( p = 0.02) were more common in standard percutaneous nephrolithotomy group than in mini-percutaneous nephrolithotomy group. Subgroup analysis showed only blood transfusion for 30F and 22–26F standard percutaneous nephrolithotomy group was more common than mini-percutaneous nephrolithotomy ( p < 0.0001, p = 0.005, respectively).

Conclusion:

Standard percutaneous nephrolithotomy was associated with higher leakage, bleeding, blood transfusion, and renal pelvis perforation, but had a shorter operation time. Tract size of 30F improved the stone-free rate compared with mini-percutaneous nephrolithotomy, but led to more complications. Tract size of 22–26F was no better than 30F or mini-percutaneous nephrolithotomy.

Enhanced super-mini-PCNL (eSMP): low renal pelvic pressure and high stone removal efficiency in a prospective randomized controlled trial

OBJECTIVE

In the present prospective randomized controlled trial (RCT), enhanced-SMP (eSMP) and conventional Chinese mini-PCNL (mPCNL) were compared to test the low renal pelvic pressure (RPP) and high stone removal efficiency in eSMP.

MATERIALS AND METHODS

Hundred patients with 2-5 cm renal calculus were enrolled. Renal pelvic pressure, operation time, lithotripsy time, removed stone volume, and complications were compared between eSMP and mPCNL statistically.

RESULTS

There was no significant difference in removed stone volume between mPCNL and eSMP (8.09 ± 3.36 vs. 7.88 ± 3.07 mm³, t = 0.320, p = 0.750), lithotripsy time in mPCNL was longer than eSMP (49.6 ± 19.5 vs. 34.9 ± 14.2 min, t = 4.152, p < 0.001), thus stone removal efficiency was higher in eSMP (13.71 ± 1.18 vs. 9.82 ± 1.24 mm³/h, t = 15.499, p < 0.001). Intra-operative RPP in mPCNL was higher than eSMP (17.72 ± 3.33 vs. 12.03 ± 2.37 mmHg, t = 9.524, p < 0.001); accumulated time of backflow status (RPP > 30 mmHg) in mPCNL was longer than eSMP (23.3 ± 16.9 vs. 3.7 ± 4.2 s, t = 7.710, p < 0.001). There was no significant difference in postoperative fever rate between mPCNL and eSMP (12.77% vs. 4.34%, χ² = 2.095, p = 0.148), nor final stone-free rate (87.2% vs. 91.3%, χ² = 0.401, p = 0.526). Hospital stay in eSMP was shorter than mPCNL (2.54 ± 0.72 vs. 3.00 ± 0.88, t = 2.724, p = 0.008).

CONCLUSION

Enhanced SMP (eSMP) was safe and effective in the management of 2-5 cm renal calculus. It can keep a lower renal pelvic pressure and a higher stone removal efficiency when compared to conventional Chinese mini-PCNL.

CLINICAL TRIAL REGISTRATION

NC03206515.

RIRS with Vacuum-Assisted Ureteral Access Sheath versus MPCNL for the Treatment of 2-4 cm Renal Stone

OBJECTIVE

Comparison of outcomes between RIRS with vacuum-assisted ureteral access sheath (V-UAS) and MPCNL in the treatment of renal stone.

MATERIALS AND METHODS

28 patients with 2-4 cm renal stone were treated using RIRS with 14/16 F V-UAS. The outcomes were compared to those who underwent MPCNL with 16 F Amplatz sheath using a matched-pair analysis in a 1 : 2 scenario. Matching criteria included stone size, location and laterality, gender, age, BMI, and degree of hydronephrosis. Patients' demographics, perioperative and postoperative characteristics, complications, stone-free rate (SFR), and auxiliary procedures were compared.

RESULTS

Mean operative times for the RIRS and MPCNL groups were 72.4 ± 21.3 minutes and 67.4 ± 25 minutes (P = 0.042). Postoperative pain was significantly less in the RIRS group. The initial SFR was 50% for the RIRS group and 73.2% for the MPCNL group (P = 0.035). The final SFR at postoperative three months improved to 89.3% for the RIRS group and 92.9% for the MPCNL group (P = 0.681). The auxiliary procedure rates were higher in the RIRS group (42.9% vs. 25%, P = 0.095). The overall complication rate in the RIRS group was lower, but the significant difference was not found.

CONCLUSION

In the treatment of 2-4 cm renal stone, using V-UAS in RIRS can improve surgical efficiency with lower postoperative early pain scores. Comparing with MPCNL, its initial SFR was more depressed, and there is still a trend towards requiring more auxiliary procedures to achieve comparable final SFR.

Multitract percutaneous nephrolithotomy in staghorn calculus

Staghorn calculi are branched stones which occupy a majority portion of the pelvicaliceal system. An untreated staghorn calculus over time can damage the kidney and deteriorate its function and/or cause life threatening sepsis. Total stone clearance is an important goal in order to eradicate any infective focus, relieve obstruction, prevent recurrence and preserve the kidney function. Percutaneous nephrolithotomy (PCNL) is currently the accepted first-line treatment option for staghorn calculi. The options available are single-tract PCNL with an auxiliary procedure like shockwave lithotripsy, single-tract PCNL with flexible nephroscopy, or multitract PCNL. Each has its own pros and cons. But the ultimate goal of treatment for any patient with staghorn calculi should be safety, cost-effectiveness, and to achieve total stone clearance. With this article, we review the management of staghorn calculi with multiple percutaneous (“multitract”) access, its advantages and disadvantages and its current position by studying the various published materials across the globe.

The efficacy and safety of miniaturized percutaneous nephrolithotomy versus standard percutaneous nephrolithotomy: A systematic review and meta-analysis of randomized controlled trials

Purpose

Our aim was to assess the efficacy and safety of miniaturized percutaneous nephrolithotomy (mPCNL) versus standard PCNL (sPCNL) to provide higher-level evidence.

Materials and Methods

Eligible randomized controlled trials were identified from electronic databases. The data analysis was performed by the Cochrane Collaboration's software RevMan 5.3.

Results

A total of 1,219 patients from 9 articles published between 2004 and 2019 were included. Compared with those who received sPCNL, patients who received mPCNL experienced a higher stone-free rate (SFR) (odds ratio [OR], 1.43; 95% confidence interval [CI], 1.03–1.99; p=0.03), lower transfusion rates (OR, 0.33; 95% CI, 0.17–0.63; p=0.0007), and lower drops in hemoglobin (mean difference [MD], −0.72; 95% CI, −1.04 to −0.40; p<0.00001), but the operative time seemed to be significantly longer (MD, 10.98; 95% CI, 3.64–18.32; p=0.003). Of note, there was no significant difference between the two groups regarding the SFR (p=0.09) for renal calculi ≥2 cm. In addition, the meta-analysis results showed no significant differences between the groups regarding urine leakage (p=0.60), postoperative fever (p=0.71), impaired ventilation (p=0.97), or total complications (p=0.29) with no heterogeneity between trials. These results remain unaffected with regard to renal calculi ≥2 cm.

Conclusions

Our findings suggested that mPCNL had a higher SFR than sPCNL and there was no significant difference between the two groups for renal stones ≥2 cm. Besides, mPCNL tended to be associated with significantly less bleeding and a lower transfusion rate, but the duration of the procedure seemed to be significantly longer.

Mini PCNL Over Standard PCNL: What Makes it Better?

The incidence of small- and medium-size renal stones is rising. Stone clearance, bleeding, urine leak, and infectious complications are major concerns for urologists. They can choose the best technique from a list of armamentarium available. Minimally invasive approach like percutaneous nephrolithotomy (PCNL) has significantly influenced renal stone management since 1976. Miniaturization of the instruments innovate more effective and safer alternatives for urolithasis management. The outcome of mini-PCNL is explored and compared with standard PCNL in this review. Original research articles were reviewed using a systematic approach (keyword electronic database search). Duplicates were excluded in each step and 19 original articles out of 156 hits were analyzed. Mini-PCNL has significantly less bleeding complications and hospital stay. There were no significant difference in stone free rate between mini-PCNL and standard PCNL. The stone-free rate and complications rates were less dependent on the technique of puncture, tract dilatation, and energy used to fragment stones. The total operative time became slightly longer in mini-PCNL attributed to the sheath size and stone fragments retrieval. We found that mini-PCNL is as effective as standard PCNL with fewer complications. Stone burden is the key factor responsible for overall stone-free rate. However, the recommendation is limited by quality of study and the sample sizes.

Contemporary best practice in the management of staghorn calculi

Staghorn calculi are complex renal stones that occupy the majority of the renal collecting system. These stones are associated with high morbidity and can lead to recurrent urinary tract infections, urosepsis, renal deterioration, and death if left untreated. Managing patients with staghorn calculi can be challenging. Fortunately, advances in technology and endourology techniques have enabled urologists to effectively treat these stones with minimal morbidity to the patient. This article describes the contemporary best practices in the initial evaluation, management, and follow up of patients with staghorn calculi to help the practicing urologist navigate this complex condition.

Updates in endourological management of urolithiasis

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

Guide sheath-assisted ureteroscope lithotripsy for upper ureteral calculi: An observational study on 81 cases

The present study assessed the clinical efficacy of guide sheath-assisted ureteroscope lithotripsy in the treatment of upper ureteral calculi. A total of 81 patients with upper ureteral calculi underwent ureteroscope lithotripsy assisted by a guide sheath between January 2012 and June 2014; of these, 63 patients were successfully treated with simple rigid ureteroscope lithotripsy assisted by a ureteral access sheath, and 18 patients were successfully treated with rigid and flexible ureteroscope lithotripsy assisted by a guide sheath. At 1 day after the surgery, ultrasound examination of kidneys, ureters and bladder, and urinary system computed tomography were used to re-check for residual stones, and 69 patients had stones with a diameter of <2 mm in the renal pelvis, while 12 had stones of 2-4 mm in diameter. The operation time was 30-115 min (average, 56.0±4.8 min); all patients underwent a successful surgical procedure. A total of 7 patients had an elevated temperature 37.4-39.1°C (mean temperature, 37.7±0.3°C) after the surgery, but no other major complications were noted. After 1 month, the residual stones were completely discharged, so that the stone clearance rate was 100%. All patients were followed up for 3-12 months and no associated complications occurred. Overall, ureteroscope lithotripsy assisted by a guide sheath for the treatment of upper ureteral calculi had the benefit of water injection and reflux functions, as well as enhanced vision, reduced pressure within the renal pelvis, good discharge of stones as well as an improved efficiency and success rate compared with simple ureteroscopic lithotripsy.

Endourologic strategies for a minimally invasive management of urinary tract stones in patients with urinary diversion

Objective

To present our experience in minimally invasive management of urinary tract stones in patients with urinary diversion.

Materials and Methods

We retrospectively reviewed 26 patients with urinary tract stones after cystectomy and urinary diversion. The types of urinary diversion were ileal conduit, colon conduit, ileal orthotopic neobladder in 19, 4, and 3 patients, respectively. At postoperative days 2, a plain KUB and urinary ultrasonography were performed in order to assess stone fragmentation or hydronephrosis. According to postoperative imaging, stone free rate (SFR) was defined as complete absence of fragments or residual stones less than 4mm.

Results

19 patients were treated with minimally invasive percutaneous lithotripsy (MPCNL) and 2 patients required second-look MPCNL. Anterograde flexible ureteroscopy was performed in 2 patients, while in 2 patients a combined anterograde and retrograde approach was required. Three reservoir stones were treated by transurethral neo-bladder lithotripsy. Postoperative significant complications occurred in 2 patients (7.7%). The highest percentage of stone composition was struvite, as a result of chronic urinary tract infection (UTI). SFR was 88.5% (23 of 26).

Conclusions

Our experience showed that MPCNL is a safe and effective treatment modality with little morbidity for renal and upper ureteral stones in patients with urinary diversion. For middle and lower ureteral stones, an anterograde approach could be also considered as a first line treatment, but a combined anterograde and retrograde approach was required when the anterograde access alone cannot provide acceptable results.

Miniaturised percutaneous nephrolithotomy: Its role in the treatment of urolithiasis and our experience

Miniaturized percutaneous nephrolithotomy (PCNL) procedures have gained increased popularity in recent years. They aim to reduce percutaneous tract size in order to lower complication rates, while maintaining high stone-free rates. Recently, miniaturized PCNL techniques have further expanded, and can currently be classified into mini-PCNL, minimally invasive PCNL (MIP), Chinese mini-PCNL (MPCNL), ultra-mini-PCNL (UMP), micro-PCNL, mini-micro-PCNL, and super-mini-PCNL (SMP). However, despite its minimally-invasive nature, its potential superiority in terms of safety and efficacy when compared to conventional PCNL is still under debate. The aim of this review is to summarise different available modalities of miniaturized PCNL, details of instruments involved, and their corresponding safety and efficacy. In particular, this article highlights the role of the SMP and our experience with this novel technique in management of urolithiasis. Overall, miniaturized PCNL techniques appear to be safe and effective alternatives to conventional PCNL for both adult and pediatric patients. Well-designed, randomized studies are required to further investigate and identify specific roles of miniaturized PCNL techniques before considering them as standard rather than alternative procedures to conventional PCNL.

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.

Mini vs standard percutaneous nephrolithotomy for renal stones: a comparative study

To compare the outcome of mini-percutaneous nephrolithotomy (Mini-PNL) versus standard-PNL for renal stones. Retrospective study was performed between March 2010 and May 2013 for patients treated by Mini-PNL or standard-PNL through 18 and 30 Fr tracts, respectively, using pneumatic lithotripsy. Semirigid ureteroscope (8.5/11.5 Fr) was used for Mini-PNL and 24 Fr nephroscope for standard-PNL. Both groups were compared in stone free rate(SFR), complications and operative time using Student-t, Mann-Whitney, Chi square or Fisher's exact tests as appropriate in addition to logistic regression analysis. P < 0.05 was considered statistically significant. Mini-PNL (378) and standard-PNL (151) were nearly comparable in patients and stones criteria including stone burden (3.77 ± 2.21 vs 3.77 ± 2.43 cm²; respectively). There was no significant difference in number of tracts or supracostal puncture. Mini-PNL had longer operative time (68.6 ± 29.09 vs 60.49 ± 11.38 min; p = 0.434), significantly shorter hospital stay (2.43 ± 1.46 vs 4.29 ± 1.28 days) and significantly higher rate of tubeless PNL (75.1 vs 4.6%). Complications were significantly higher in standard-PNL (7.9 vs 20.5%; p < 0.001). SFR was significantly lower in Mini-PNL (89.9 vs 96%; p = 0.022). This significant difference was found with multiple stones and large stone burden (> 2 cm²), but the SFR was comparable between both groups with single stone or stone burden ≤ 2 cm. Logistic regression analysis confirmed significantly higher complications and SFR with standard-PNL but with significantly shorter operative time. Mini-PNL has significantly lower SFR when compared to standard-PNL (but clinically comparable) with markedly reduced complications and hospital stay. Most of cases can be performed tubeless. The significant difference in SFR was found with multiple stones or large stone burden (> 2 cm²), but not with single stones or stone burden ≤ 2 cm².

Ultra-mini-percutaneous nephrolithotomy (PCNL) versus standard PCNL: A randomised clinical trial

Objective

To assess the effectiveness and advantages of ultra-mini-percutaneous nephrolithotomy (UM-PCNL) versus standard PCNL (S-PCNL), as one of the most important differences between the various PCNL techniques is the size of the renal access, which contributes to the broad spectrum of complications and outcomes.

Patients and methods

This clinical randomised trial was conducted in 2016. In all, 70 patients with renal or upper ureteric stones of 10–20 mm in diameter, who were candidates for PCNL, were divided equally into two groups. Group A, underwent UM-PCNL using a 9.8-F ureteroscope through a 16-F sheath; and Group B, underwent S-PCNL using a 24-F nephroscope through a 30-F sheath. The stones were fragmented by pneumatic lithotripsy. Any perioperative complications and need for analgesia were recorded, and postoperative pain was assessed in both groups using a visual analogue scale (VAS).

Results

There were statistically significant differences in postoperative haemoglobin values, haemoglobin drop, transfusion rate, duration of hospitalisation and postoperative VAS pain score between the groups (P < 0.05). There were no significant differences in operation time, need for auxiliary procedures or stone-free rate.

Conclusion

A minimally invasive UM-PCNL using a 9.8-F ureteroscope can play an important role in the treatment of symptomatic renal and upper ureteric stones of <20 mm in diameter with lesser blood loss, duration of hospitalisation, need of transfusion, and postoperative pain compared with S-PCNL.

Small-calibre percutaneous nephrolithotomy (SC-PCNL). Therapeutic decision algorithm

INTRODUCTION

The progressive reduction in the calibre of the tract in percutaneous kidney surgery to the point of miniaturisation has expanded its use to smaller stones that until now have been treated with extracorporeal shock wave lithotripsy (ESWL) and retrograde intrarenal surgery (RIRS).

OBJECTIVE

To provide an update on the various techniques of small-calibre nephrolithotomy (SC-PCNL) analyse their efficacy, safety and indications and determine their degree of implantation at this time.

MATERIAL AND METHODS

We performed a review in PubMed of Spanish and English medical literature on the various techniques of SC-PCNL.

RESULTS

The use of SC-PCNL has reduced the morbidity associated with standard PCNL, particularly bleeding, and has enabled tubeless nephrolithotomy with greater safety. There are various techniques with blurred terminology (Miniperc, Microperc, Mini-microperc, Ultraminiperc), which differ in terms of gauge employed and in certain technical aspects that require their indications be specified. Currently, SC-PCNL competes with techniques that are less invasive than standard PCNL such as ESWL and the RIRS in treating small stones, but the role of SC-PCNL is still not sufficiently understood and continues to be the subject of debate.

CONCLUSIONS

The indications for PCNL are expanding to small stone sizes due to the miniaturisation of the technique. PCNL competes in this field with ESWL and RIRS. Larder studies are needed to establish the specific indications for PCNL in treating nephrolithiasis.

[S2k guidelines on diagnostics, therapy and metaphylaxis of urolithiasis (AWMF 043/025) : Compendium]

Every tenth German citizen will suffer from at least one urinary calculus during the lifetime. The diagnostics, treatment and follow-up treatment of urolithiasis are, therefore, part of the daily routine practice for all urologists in hospitals and private practices as well as in many other disciplines, such as general practitioners, internists, nephrologists and pediatricians. Although the diagnostics and therapy have experienced substantial alterations over the last 10 years, the possibilities of metabolic diagnostics and secondary prevention for patients at risk are, unfortunately and unjustly, in many places very poorly represented. The present S2k guidelines, which for the first time were established in an interdisciplinary consensus process, represent the current practical recommendations and, whenever possible, use tables and algorithms in order to facilitate easy reference in the routine daily work. Last but not least, this greatly simplifies the measures for metaphylaxis.

Treatment for residual stones using flexible ureteroscopy and holmium laser lithotripsy after the management of complex calculi with single-tract percutaneous nephrolithotomy

This study validated the effectiveness and safety of the treatment for residual stones using flexible ureteroscopy (fURS) and holmium laser (0.6-1.2 J, 20-30 Hz) lithotripsy via a fiber with a 200-μm core diameter and 0.22 numerical aperture (NA) after the management of complex calculi with single-tract percutaneous nephrolithotomy (PCNL). Between January 2014 and June 2016, 27 consecutive patients with complex calculi underwent fURS and holmium laser lithotripsy after a planned single-tract PCNL. Among the 27 patients with complex calculi, 9 had full staghorn calculi, 7 had partial staghorn calculi, and 11 had multiple calculi. After the first single-tract PCNL session, the mean stone size and mean stone surface area were 18.0 ± 10.7 mm and 181.9 ± 172.2 mm², respectively. Treatment for residual stones with fURS and holmium laser lithotripsy was successfully completed and was performed without intraoperative complications. The mean operative time of the fURS procedure was 69.1 ± 23.6 min, and the mean hospital stay was 5.3 ± 2.4 days. The mean decrease in the hemoglobin level was 7.3 ± 6.5 g/l. After the fURS procedure, the overall stone-free rate was 88.9%. The overall postoperative complication rate was 14.8% (Clavien grade I 11.1%; Clavien grade II 3.7%). The current approach tested here combines the advantages of both PCNL and fURS and effectively manages complex calculi with a high stone-free rate (SFR) (88.9%). This approach also reduced the number of treatment sessions, the number of percutaneous access tracts, and the blood loss and potential morbidity associated with multiple tracts.

Management of symptomatic caliceal diverticular calculi: Minimally invasive percutaneous nephrolithotomy versus flexible ureterorenoscopy

Objective

To retrospectively evaluate appropriate treatment for patients with symptomatic caliceal diverticular calculi, by comparing the therapeutic outcomes for those undergoing minimally invasive percutaneous nephrolithotomy (MPCNL) and flexible ureterorenoscopy (F-URS).

Methods

From March 2009 to May 2014, 36 consecutive patients with caliceal diverticular calculi were divided into 2 groups: 21 patients underwent MPCNL, and 15 were treated by F-URS. All procedures were performed by one surgical group, which ensured relatively constant parameters. Patient characteristics, operative time, hospital stay after surgery, stone-free rate, symptomatic improvement rate, complications, diverticular obliteration, and stone composition were analyzed retrospectively in the 2 groups.

Results

Patient preoperative variables were comparable between the two groups, with no significant difference (P > 0.05). Mean operative time was 136.9 ± 22.8 min in the MPCNL group and 117.3 ± 24.3 min in the F-URS group (P = 0.019). Hospital stay was significantly longer in the MPCNL group than in the F-URS group (9.4 ± 3.1 vs. 6.9 ± 2.1 days, P = 0.010). The stone-free rates after MPCNL and F-URS were 90.5% (19/21) and 60.0% (9/15), respectively (P = 0.046). Additionally, 71.4% (15/21) of patients in the MPCNL group and 46.7% (7/15) of patients in the F-URS group had symptomatic improvement at the 6-month follow-up (P = 0.175); the rates of complications in the 2 groups were 19.0% (4/21) and 13.3% (2/15), respectively (P = 0.650). Complete diverticular obliteration was achieved in 16 (76.2%) cases in the MPCNL group and 5 (33.3%) cases in the F-URS group (P = 0.017). The distributions of calcium oxalate and hydroxyapatite in the stones were 66.7% (14/21) and 33.3% (7/21), respectively, in the MPCNL group; however, the distributions in the F-URS group were 46.7% (7/15) and 53.3% (8/15), respectively (P = 0.310).

Conclusion

MPCNL is an effective method for the treatment of caliceal diverticular calculi. However, F-URS is an alternative technique in selected patients with a patent infundibulum, despite lower stone-free rates than with MPCNL. Fulguration of the diverticular lining with a high-power holmium laser and permitting the cavity to collapse are useful to increase the chance of diverticular obliteration.

Randomized Study of Ureteral Catheter vs Double-J Stent in Tubeless Minimally Invasive Percutaneous Nephrolithotomy Patients

OBJECTIVE

To prospectively analyze and compare the outcomes of using externalized ureteral catheter (EUC) vs Double-J ureteral stent (DJ) in tubeless minimally invasive percutaneous nephrolithotomy (MPCNL).

PATIENTS AND METHODS

A total of 109 patients underwent tubeless MPCNL in our institute and have been enrolled into this study. Fifty-six and 53 patients had EUC and DJ positioning at the conclusion of the procedure, respectively. The two approaches have been compared for operative time, intraoperative blood loss, postoperative visual analogue pain scale (VAS) score, analgesic requirement, stent-related symptoms, hospital stay, degree of vesicoureteral reflux (VUR) on the operative side, and complications according to the modified Clavien system.

RESULTS

There were no statistically significant differences between the two groups regarding the mean operative times, mean VAS scores, analgesic requirements, mean hemoglobin drop, mean hospital stay, and overall complication rate. However, compared with DJ group, EUC group presented fewer postoperative stent-related symptoms and less occurrence of severe VUR (p < 0.05).

CONCLUSION

Positioning EUC in tubeless MPCNL is a safe alternative to DJ in patients with renal or upper ureteral calculi. EUC provides several benefits: obviated the need of a second endoscopic procedure, reduced stent-related discomfort, and lowered the occurrence of severe VUR.

Safety and efficacy of minimally invasive percutaneous nephrolithotomy in the treatment of patients with medullary sponge kidney

The purpose of this study was to review the safety and efficacy of the minimally invasive percutaneous nephrolithotomy in the treatment of medullary sponge kidney patients with complex renal calculi. Sixteen medullary sponge kidney patients with complex renal calculi underwent minimally invasive percutaneous nephrolithotomy procedures in our center were entered into this retrospective study. The data analyzed included patients' demographics, stone burden, operative time, operative blood loss, length of hospital stay, complications according to the modified Clavien system, and stone-free rate. All the patients in this study had complex renal stones that included 14 multiple stones and 3 partial staghorn calculi. The mean stone surface area was 779.5 ± 421.1 mm(2). Preoperative urinary tract infection was noted in 5 (31.2 %) patients. Minimally invasive percutaneous nephrolithotomy was successfully completed in 15 renal units in 14 patients. Two patients failed the procedure. The mean operative time was 87.3 ± 32.3 min. Mean hemoglobin drop was 25.3 ± 16.5 g/L. An initial stone-free rate of 60 % was achieved after the procedure, and the final stone-free rate was 86.6 % after auxiliary second look and/or shock-wave lithotripsy. Clavien grade I and II complications occurred in 3 (21.4 %) patients including the one (7.1 %) patient who required transfusion. All the complications were managed conservatively. No major complications occurred. This retrospective analysis confirmed that minimally invasive percutaneous nephrolithotomy was a safe alternative treatment for the medullary sponge kidney patients with complex renal calculi. This procedure provided an acceptable stone-free rate and low incidence of high-grade complications. Stone-free rate further could be further improved with auxiliary procedures.

Recent advancement or less invasive treatment of percutaneous nephrolithotomy

Since its initial introduction in 1976, percutaneous nephrolithotomy (PCNL) has been widely performed for the management of large renal stones and currently is recommended for staghorn calculi, kidney stones larger than 2 cm, and shock wave lithotripsy-resistant lower pole stones greater than 1 cm. However, except for open and laparoscopic surgery, PCNL is the most invasive of the minimally invasive stone surgery techniques. Over the years, technical and instrumental advances have been made in PCNL to reduce morbidity and improve effectiveness. A thorough review of the recent literature identified five major areas of progress for the advancement of PCNL: patient positioning, method of percutaneous access, development of lithotriptors, miniaturized access tracts, and postoperative nephrostomy tube management. This review provides an overview of recent advancements in PCNL and the outcomes of each area of progress and notes how much we achieve with less invasive PCNL. This information may allow us to consider the future role and future developments of 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.

Comparing Bleeding Complications of Double and Single Access Totally Tubeless PCNL: Is It Safe to Obtain More Accesses?

PURPOSE

To assess bleeding complications in totally tubeless double-access percutaneous nephrolithotomy (PCNL) and compare it with the single-access method.

METHODS

One hundred and seven patients with large or scattered renal stones were enrolled in this cohort study. Totally tubeless PCNL with one access (group A, 70 cases) or two accesses (group B, 37 cases) was done and bleeding was assessed by measuring the hemoglobin drop of the patients, blood transfusion rate and need for performing angioembolization.

RESULTS

The mean (SD) hemoglobin drops in groups A and B were 1.97 (1.24) and 2.31 (1.24), respectively; p = 0.176. Blood transfusion rates in two groups were 7.1 and 10.8% (p = 0.716), respectively. None of our patients required angioembolization. The average hemoglobin drop and blood transfusion rate with double tracts were approximately near to those in single tract group and in acceptable ranges. The average hospital stay in groups A and B were 3.1 and 3.2 days (p = 0.074), respectively. There was no leakage from puncture site/s and stone free rates in the two groups were 85.7 and 97.3% (p = 0.093).

CONCLUSION

Totally tubeless double-access PCNL is feasible and bleeding complications are comparable to single access totally tubeless PCNL making it an effective strategy to achieve more stone free rates.

Mini percutaneous nephrolithotomy in the treatment of renal and upper ureteral stones: Lessons learned from a review of the literature

The aim of this review is to present the most recent data regarding the indications of mini percutaneous nephrolithotomy (PCNL), the results and the complications of the method. Medline was searched from 1997 to January 2014, restricted to English language. The Medline search used a strategy including medical subject headings and free-text protocols. PCNL is a well-established treatment option for patients with large and complex renal calculi. In order to decrease morbidity associated with larger instruments like blood loss, postoperative pain and potential renal damage, a modification of the technique of standard PCNL has been developed. This is performed with a miniature endoscope via a small percutaneous tract (11–20 F) and was named as minimally invasive or mini-PCNL. This method was initially described as an alternative percutaneous approach to large renal stones in a pediatric patient population. Furthermore, it has become a treatment option for adults as well, and it is used as a treatment for calculi of various sizes and locations. However, the terminology has not been standardized yet, and the procedure lacks a clear definition. Nevertheless, mini-PCNL can achieve comparable stone-free rates to the conventional method, even for large stones. It is a safe procedure, and no major complications are reported. Although less invasiveness has not been clearly demonstrated so far, mini-PCNL is usually related to less blood loss and shorter hospital stay than the standard method.

Percutaneous-based management of Staghorn calculi in solitary kidney: combined mini percutaneous nephrolithotomy versus retrograde intrarenal surgery

INTRODUCTION

Mini percutaneous nephrolithotomy (mini-PCNL) and retrograde intrarenal surgery (RIRS) are well-established techniques with little morbidity. The combined use of standard PCNL and the mini-PCNL or the RIRS technique was evaluated and compared to investigate their own role in the management of staghorn calculi in solitary kidney.

MATERIALS AND METHODS

23 patients received combined standard PCNL and mini-PCNL (group 1), and 22 patients received combined standard PCNL and RIRS (group 2). The treatment results and complications were evaluated and compared.

RESULTS

The mean operation time was 128.8 ± 9.1 min in group 1 and 109.8 ± 10.7 min in group 2 (p < 0.001). The decrease in hemoglobin level in group 1 was significantly higher than that in group 2 (3.5 ± 0.6 vs. 2.1 ± 0.5 g/dl, p < 0.001). The final stone-free rate was significantly higher (p = 0.038) in group 2 (90.9%) than in group 1 (65.2%).

CONCLUSIONS

Combined standard PCNL and RIRS technique can extract the majority of staghorn calculi quickly by PCNL with EMS Lithoclast, and RIRS used simultaneously can reduce the need for multiple tracts and therefore reduce blood loss and potential morbidity related to multiple tracts, shorten the operation time and achieve a high stone-free rate.