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

Endourological Management of Renal Stones: A Systematic Review, Bayesian Network Meta-analysis and Meta-regression

OBJECTIVE

To compare stone-free rates (SFRs), operative times, and transfusion rates of various endoscopic techniques for kidney stone management.

METHODS

A systematic review was performed, identifying studies comparing the different endoscopic techniques in patients with renal stones. Studies were grouped by location and size of stones (lower pole, 1-2cm, and >2 cm). Data were extracted to build a Bayesian network modeling the comparisons. Meta-regression adjusted for variations in stone-free definitions. Odds ratios (OR) with 95% credible intervals were reported.

RESULTS

A total of 40 studies were included for analysis, providing a total population of 6696 patients. For lower pole stones, both percutaneous nephrolithotomy (PCNL) (OR 2.0 [1.2, 3.3]) and mini-PCNL (OR 2.3 [1.5, 3.6]) showed increased SFRs when compared to retrograde intrarenal surgery (RIRS), while micro-PCNL exhibited a non-significant difference (OR 0.94 [0.39,2.3]). For stones between 1-2cm, mini-PCNL showed an increased SFR (OR 2.5 [1.5,4.1]) when compared to RIRS; however, there was no significant difference in SFR among the rest of the interventions when compared to RIRS. For stones larger than 2 cm, PCNL, mini-PCNL, and ultramini-PCNL resulted in higher SFRs compared to RIRS.

CONCLUSION

For 1-2cm upper pole/interpolar stones, percutaneous approaches except mini-PCNL did not achieve superior SFRs compared to RIRS. For >2 cm stones and lower pole stones, all percutaneous methods, except micro-PCNL, exhibited higher stone clearance than RIRS.

Can suction technology be a potential game changer that reshapes pediatric endourological interventions? Results from a scoping review

PURPOSE

To systematically review the use of suction/vacuum-assisted retrograde intrarenal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) in children/adolescents with kidney stones.

METHODS

The PICOS model (Patient Intervention Comparison Outcome Study type) was used to frame and answer the clinical question; P: children and adolescent men with kidney stones; I: use of suction during PCNL or RIRS; C: no suction devices or none; O: complications and stone-free rate (SFR); S: prospective and retrospective studies; case reports. The literature search was performed on 14th May 2024 using Embase, PubMed, and Scopus. Only English papers were accepted.

RESULTS

Ten articles were included. There were 9 papers on mini-PCNL and the remaining one compared mini-PCNL with RIRS. PCNL studies found excellent SFR (73-100%) with zero transfusion rate and a low rate of infectious complications (fever up to 9.6% and sepsis rate of 1%). Among these studies, there was a case report on the use of shock pulse lithotripter with complete stone clearance.

CONCLUSIONS

Our review shows that there is little data on the use of suction/vacuum-assisted mini-PCNL/RIRS in kidney stone children/adolescents. However, these preliminary data demonstrated that vacuum-assisted mini-PCNL had excellent SFR with a low rate of complications.

International Alliance of Urolithiasis (IAU) consensus on miniaturized percutaneous nephrolithotomy

Over the past three decades, there has been increasing interest in miniaturized percutaneous nephrolithotomy (mPCNL) techniques featuring smaller tracts as they offer potential solutions to mitigate complications associated with standard PCNL (sPCNL). However, despite this growing acceptance and recognition of its benefits, unresolved controversies and acknowledged limitations continue to impede widespread adoption due to a lack of consensus on optimal perioperative management strategies and procedural tips and tricks. In response to these challenges, an international panel comprising experts from the International Alliance of Urolithiasis (IAU) took on the task of compiling an expert consensus document on mPCNL procedures aimed at providing urologists with a comprehensive clinical framework for practice. This endeavor involved conducting a systematic literature review to identify research gaps (RGs), which formed the foundation for developing a structured questionnaire survey. Subsequently, a two-round modified Delphi survey was implemented, culminating in a group meeting to generate final evidence-based comments. All 64 experts completed the second-round survey, resulting in a response rate of 100.0%. Fifty-eight key questions were raised focusing on mPCNLs within 4 main domains, including general information (13 questions), preoperative work-up (13 questions), procedural tips and tricks (19 questions), and postoperative evaluation and follow-up (13 questions). Additionally, 9 questions evaluated the experts' experience with PCNLs. Consensus was reached on 30 questions after the second-round survey, while professional statements for the remaining 28 key questions were provided after discussion in an online panel meeting. mPCNL, characterized by a tract smaller than 18 Fr and an innovative lithotripsy technique, has firmly established itself as a viable and effective approach for managing upper urinary tract stones in both adults and pediatrics. It offers several advantages over sPCNL including reduced bleeding, fewer requirements for nephrostomy tubes, decreased pain, and shorter hospital stays. The series of detailed techniques presented here serve as a comprehensive guide for urologists, aiming to improve their procedural understanding and optimize patient outcomes.

A new alternative to percutaneous nephrolithotomy: A case report

INTRODUCTION

Percutaneous nephrolithotomy (PCNL) is a common procedure for kidney stone removal, involving a small incision in the back and insertion of a nephroscope to extract the stones. Recent advancements include super-mini PCNL, employing smaller instruments for less invasive access to the kidney. However, conventional PCNL often requires tract dilation, which can lead to potential complications.

CASE PRESENTATION

This case report presents the successful application of our surgical technique using the basic principles of PCNL with the aid of a pediatric trocar cystostomy and ultrasound guidance as a new alternative for super-mini PCNL, offering safer access with reduced bleeding risk and shorter recovery. The surgery was performed on a 55-year-old female with bilateral kidney stones, with the stone in the left kidney being larger than the one in the right kidney. The procedure was completed within 60 min without significant postoperative complications.

DISCUSSION

Our new alternative for PCNL offers benefits such as reduced invasiveness, shorter recovery time, decreased risk of complications, and minimal changes in postoperative hemoglobin levels. This new alternative can be performed in developing country hospitals that do not have the expensive PCNL equipment.

CONCLUSION

This new alternative of PCNL with pediatric trocar cystostomy proves to be effective and safe.

Super-mini PCNL (SMP) with suction versus standard PCNL for the management of renal calculi of 1.5 cm-3 cm: a randomized controlled study from a university teaching hospital

PURPOSE

To assess the safety and efficacy of super-mini PCNL (SMP, 14 Fr) when compared to standard PCNL (sPCNL, 24-30 Fr) in the management of renal calculi of size ranging from 1.5 to 3 cm.

METHODS

From February 2021 to January 2022, a total of 100 patients were randomized to either SMP group or sPCNL group in a 1:1 ratio (50 in each group) using computer-generated simple randomization. Demographic data, stone characteristics, operative times, perioperative complications, blood transfusions, postoperative drop in haemoglobin, postoperative pain, duration of hospital stay and stone-free rates were compared between the two groups.

RESULTS

Mean stone volume (2.41 cm2 vs 2.61 cm2) and stone-free rates (98% vs 94%, p = 0.14) were similar in both the SMP and sPCNL groups, respectively. The SMP group had significantly longer mean operative times (51.62 ± 10.17 min vs 35.6 ± 6.8 min, p = 0.03). Intraoperative calyceal injury (1/50 vs 7/50, p = 0.42) and mean postoperative drop in haemoglobin (0.8 ± 0.7 g/dl vs 1.2 ± 0.81, p = 0.21) were lower in the SMP group, but not statistically significant. SMP group showed significantly lower mean postoperative pain VAS scores (5.4 ± 0.7 vs 5.9 ± 0.9, p = 0.03) and mean duration of hospital stay (28.38 ± 3.6 h vs 39.84 ± 3.7 h, p = 0.0001). Complications up to Clavien grade 2 were comparable, with grade ≥ 3 complications higher in the standard group, but not statistically significant.

CONCLUSION

Super-mini PCNL is equally effective as standard PCNL in treating renal calculi up to 3 cm, with significantly reduced postoperative pain and duration of hospital stay and lower risk of Clavien grade ≥ 3 complications, although with higher operative times.

A retrospective comparison of Sun's tip-flexible semirigid ureterorenoscopy, super-mini percutaneous nephrolithotomy and flexible ureteroscopy applied to treat upper urinary tract calculi

BACKGROUND

This retrospective study was conducted to compare the safety and efficacy of Sun's tip-flexible semirigid ureterorenoscopy (tf-URS), super-mini percutaneous nephrolithotomy (SMP) and flexible ureteroscopy (FURS) in treating upper urinary tract calculi, including upper ureteral or renal calculi.

METHODS

We included patients with upper ureteral calculi or renal calculi 1.0-2.0 cm in size, who underwent tf-URS, SMP or FURS, respectively. The indicators reflecting safety and efficacy were compared among the three surgical techniques.

RESULTS

SMP presented with higher single stone crushing success rate, but longer operation time and postoperative hospital stay, more blood loss, and higher postoperative pain score compared with FURS and tf-URS (P < 0.05). The hospitalization cost of tf-URS group was lower than that of SMP and FURS groups (P < 0.05). The incidence of postoperative fever in tf-URS group was significantly higher than that in SMP group (P < 0.05). No significant difference was found in mucosal injury, perirenal hematoma, and stone-free rate at 3 months after surgery (P > 0.05).

CONCLUSIONS

tf-URS and FURS have the advantages in minimal invasion, hospitalization cost, patient comfort, and hospital stay while SMP has higher stone-free rate. These three surgical techniques are safe, reliable and complementary, which should be selected according to the actual situation.

Suction in Percutaneous Nephrolithotripsy: Evolution, Development, and Outcomes from Experimental and Clinical studies. Results from a Systematic Review

CONTEXT

Controversy exists regarding the therapeutic benefit of suction use during percutaneous nephrolithotripsy (PCNL).

OBJECTIVE

To review and highlight the options available in the use of suction for PCNL, and to discuss their strengths and limitations.

EVIDENCE ACQUISITION

A systematic literature search was performed using Scopus, EMBASE, and PubMed. Thirty four studies were included. There was one ex vivo study. Among clinical studies, 24 used a vacuum/suctioning sheath and nine a handpiece suction device/direct-in-scope suction. The suction technique was employed in standard, mini-PCNL, supermini-PCNL, and enhanced supermini‑PCNL techniques.

EVIDENCE SYNTHESIS

Handpiece suction devices demonstrated better safety and efficiency in treating large stones than nonsuction PCNL and in a much shorter time. Trilogy and ShockPulse-SE were equally effective, safe, and versatile for standard PCNL and mini-PCNL. The heavier handpiece makes Trilogy less ergonomically friendly. Laser suction handpiece devices can potentiate laser lithotripsy by allowing for better laser control with simultaneous suction of small fragments and dust. Integrated suction-based sheaths are available in reusable and disposable forms for mini-PCNL only. Mini-PCNL with suction reported superior outcomes for operative time and stone-free rate to mini-PCNL. This also helped minimize infectious complications by a combination of intrarenal pressure reduction and faster aspiration of irrigation fluid reducing the risk of sepsis, enhance intraoperative vision, and improve lithotripsy efficiency, which makes it a very attractive evolution for PCNL.

CONCLUSIONS

Suction devices in PCNL are reforming the way PCNL is being done. Adding suction to mini-PCNL reduces infectious complications and improves the stone-free rate. Our review shows that despite the limited evidence, suction techniques appear to improve PCNL outcomes.

PATIENT SUMMARY

In this review, we looked at the intra- and perioperative outcomes of percutaneous nephrolithotripsy (PCNL) with the addition of suction. With better stone fragmentation and fewer postoperative infections, this technology is very useful particularly for mini-PCNL.

Vacuum-assisted access sheath in supine mini-percutaneous nephrolithotomy (mini-PCNL)

INTRODUCTION

The vacuum-assisted access sheath is a new device for the treatment of kidney stones with percutaneous nephrolithotomy (PCNL).

OBJECTIVE

Our aim was to compare the stone-free rate (SFR) and complications between standard mini percutaneous nephrolithotomy (Mini-PCNL) and vacuum-assisted PCNL (Va-PCNL).

METHODS

Retrospective study of patients undergoing Mini-PCNL and Va-PCNL from January 2018 to June 2022. Va-PCNL was performed with a disposable sheath (ClearPetra®) with continuous high-flow irrigation and vacuum fluid dynamics for easier stone fragment removal. Baseline patient characteristics, surgical outcomes, perioperative and postoperative data were collected. We compared SFR and complications.

RESULTS

A total of 136 patients were identified, 57 (41,9%) underwent Va-PCNL and 79 (58,15%) Mini-PCNL. Mean operative time was significantly shorter in the Va-PCNL group (95 min.) than in Mini-PCNL (146 min; P = ,001) group. The tubeless technique was performed more frequently in Va-PCNL group (61,4% vs. 34,2%; P = ,002). We did not observe any differences in postoperative complications. The mean hospital stay was significantly lower in Va-PCNL with 1,7 ± 1,9 days per patient compared with 2,7 ± 1,5 days in the Mini-PCNL group (P = ,001). There were no differences in SFR at 3 months between Va-PCNL (71,9%) and Mini-PCNL (71,8%; P =v ,848).

CONCLUSION

Patients treated with Va-PCNL had comparable results to Mini-PCNL, showing equal SFR with similar infectious complications rates. Potential benefits of Va-PCNL include shorter operative time and postoperative stay.

Percutaneous management of upper tract stones: from mini to maxi percutaneous nephrolithotomy

PURPOSE OF REVIEW

Percutaneous nephrolithotomy (PCNL) continues as the gold standard for the surgical management of large renal stones. This short review is intended to highlight recent publications on PCNL of all tract sizes, from mini to standard.

RECENT FINDINGS

Literature on PCNL in the last 2 years has focused on several main themes - decreasing complications, improving postoperative pain control, and new technology to improve outcomes. Mini-PCNL continues to prove effective and safe, with a new vacuum sheath showing promise of improving stone-free rates and decreasing infections. In terms of infections, preoperative midstream urine culture continues to be a poor indicator of postoperative infection. One of the biggest changes to PCNL practice is the reintroduction of tranexamic acid, which has shown to significantly decrease bleeding and improve outcomes. In terms of postoperative pain control, local blocks are effective and low risk.

SUMMARY

There are many options for surgeons when it comes to PCNL from sheath size to pain management to preoperative medication to decrease bleeding. Future research will continue to highlight, which advances are the most beneficial.

Efficacy and safety of super-mini percutaneous nephrolithotomy in the treatment of urinary calculi: a systematic review and meta-analysis

BACKGROUND

Super-mini-percutaneous nephrolithotomy (SMP) is feasible and safe in adults and children with moderate-size renal calculi, but the use of SMP to remove larger calculi has yet to be determined. This study aimed to review the efficacy (stone-free rate, SFR) and safety of SMP in treating urinary calculi.

METHODS

PubMed, the Cochrane Library, and Embase were searched for eligible studies published up to May 2021. The primary outcome was the SFR. The secondary outcomes were the complications (using the Clavien-Dindo grading system), pain score, hospitalization days, and mean hemoglobin decline. All analyses were performed using the random-effects model. Nine studies (2433 patients with SMP and 2178 controls) were included.

RESULTS

SMP was not associated with an improved SFR in patients with calculi (RR = 1.05, 95%CI: 0.99-1.11). There were no differences in the occurrence of Clavien-Dindo I (RR = 0.95, 95%CI: 0.67-1.35) and Clavien-Dindo II (RR = 0.91, 95%CI: 0.58-1.42) complications between SMP and the control procedures. There were more Clavien-Dindo III complications with SMP than with the control procedures (RR = 0.71, 95%CI: 0.55-0.91), but none of the individual complications significantly differed between the two groups. Clavien-Dindo I fever appeared to be higher with SMP than with the control procedure (RR = 0.64, 95%CI: 0.50-0.83).

CONCLUSION

In terms of efficacy, there were no differences between SMP and other procedures in treating urinary calculi. Clavien-Dindo I fever and Clavien-Dindo III complications might be more frequent with SMP than other procedures.

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.

Super-Mini Percutaneous Nephrolithotomy for Nephrolithiasis: A Systematic Review and Meta-Analysis

We aimed to conduct a systematic review and meta-analysis to summarize the current evidence regarding the role of super-mini percutaneous nephrolithotomy (SMP), which refers to a 7-Fr nephroscope placed through a tract sized 10-14 Fr, in treating renal stones and compare its outcomes with the standard mini-percutaneous nephrolithotomy (PCNL) techniques. A systematic literature search was conducted on the Medline database via PubMed and SCOPUS until May 2022 to retrieve the relevant studies. The titles and abstracts of unique records were screened for eligibility, followed by the full-text screening of potentially eligible abstracts. Data extraction was performed by two independent reviewers. The risk of bias assessment was conducted based on the study design. Open Meta (Analyst) and Review Manager 5.4 were used to perform all analyses. A total of 14 studies (n = 4,323 patients) were included, with two randomized controlled trials, one single-arm trial, and 11 cohort studies. The stone-free rate (SFR) of SMP was 91.4%. The pooled analysis showed no significant difference between SFR in mini-PCNL (mean difference (MD) = 1.03, 95% confidence interval (CI) = (0.99, 1.06), p = 0.12) and flexible ureteroscopy (MD = 0.84, 95% CI = (0.4, 1.76), p = 0.65]. On the other hand, SMP had a better SFR rate when compared with retrograde intrarenal surgery (MD = 1.3, 95% CI = (1.01, 1.66), p = 0.04). The pooled mean operative time of SMP was 49.44 minutes (95% CI = (41, 57.88), p < 0.001), which was longer than mini-PCNL (MD = 1.92, p < 0.001) and shorter than ureteroscopy (MD = -17.17, p < 0.00001). In the SMP group, the postoperative complications included fever (>38°C), pain, and hematuria, with an incidence of 7.6%, 2.3%, and 3.4%, respectively. The mean length of hospital stay after SMP was 2.4 days (95% CI = (2.17, 2.7), p < 0.001). The current evidence suggests that SMP is a safe and effective technique in the management of renal stones in both children and adults.

International Alliance of Urolithiasis (IAU) Guideline on percutaneous nephrolithotomy

The International Alliance of Urolithiasis (IAU) would like to release the latest guideline on percutaneous nephrolithotomy (PCNL) and to provide a clinical framework for surgeons performing PCNLs. These recommendations were collected and appraised from a systematic review and assessment of the literature covering all aspects of PCNLs from the PubMed database between January 1, 1976, and July 31, 2021. Each generated recommendation was graded using a modified GRADE methodology. The quality of the evidence was graded using a classification system modified from the Oxford Center for Evidence-Based Medicine Levels of Evidence. Forty-seven recommendations were summarized and graded, which covered the following issues, indications and contraindications, stone complexity evaluation, preoperative imaging, antibiotic strategy, management of antithrombotic therapy, anesthesia, position, puncture, tracts, dilation, lithotripsy, intraoperative evaluation of residual stones, exit strategy, postoperative imaging and stone-free status evaluation, complications. The present guideline on PCNL was the first in the IAU series of urolithiasis management guidelines. The recommendations, tips and tricks across the PCNL procedures would provide adequate guidance for urologists performing PCNLs to ensure safety and efficiency in PCNLs.

Ultrasound-Guided Mini Percutaneous Nephrolithotomy with Suction Sheath

The mini percutaneous nephrolithotomy (PCNL) is a mainstay in the treatment of kidney calculi, particularly in case of >2 cm kidney stones, large lower pole stones, large impacted proximal ureteral stones, and residual stones after failed extracorporeal shockwave lithotripsy or retrograde intrarenal surgery. An accurate renal access represents a fundamental part of the procedure, modalities to guide the percutaneous tract preparation include ultrasound, fluoroscopy, or their combination. Both ultrasound and fluoroscopy offer several advantages and some limitations. The combined utilization of ultrasound and fluoroscopy is less adopted nowadays; however, this strategy has its merits particularly in cases where the puncture can be problematic with one imaging modality alone. Ultrasound can easily identify the posterior renal calix and surrounding visceral structures, although some situations such as obese patients, undilated collecting system or complex stones may represent a challenge. Intracaliceal blood clots and air may reflect ultrasound, reducing significantly the image quality. Therefore, the assessment of the intrarenal anatomy, the stone identification, and the ability of guiding the needle during access may decrease significantly, particularly in cases with complex stones, when multiple tracts are required. In these cases, fluoroscopy could determine the relationship between the angle and depth of the puncture needle and the target calices by rotating the C-arm to help the needle puncture and tract dilation. Therefore, the benefits of dual guidance would be beneficial during PCNL. In addition to an improved accuracy of puncture and dilation, the combined approach improves the detection of residual stones, facilitating the achievement of a stone-free state. Herein we describe our experience with this technique, describing surgical steps and troubleshooting tips of mini-PCNL in the accompanying video. Further high-quality studies are needed to demonstrate the advantages of combined utilization of ultrasound and fluoroscopy during PCNL and its optimal indications.

Intrarenal pressures during percutaneous nephrolithotomy: a porcine kidney model

BACKGROUND

Increased intrarenal pressure during endoscopic lithotripsy is associated with increased adverse outcomes. The objective of this study was to evaluate the effect of various devices on IRP during percutaneous intrarenal surgery in ex vivo porcine kidney models.

METHODS

Whole intact porcine urinary tracts were harvested. Intrarenal pressure was measured using cystometrometry software. Intrarenal pressure during PCNL was recorded using variations of percutaneous access sheath size, irrigation height of 100 cm and 60 cm, use of a ureteric catheter and use of suction. The primary outcome was absolute IRP measurements. Secondary outcomes were comparisons of IRP between techniques.

RESULTS

Using a 30 Fr vs 26 Fr access sheath and 26 Fr nephroscope the mean pressure at an irrigation height of 60 cm was significantly lower than 100 cm (p = 0.0013 vs p < 0.0001, respectively). Pressure's during mini-PCNL were significantly higher than conventional PCNL in all variations. Using the 16.5 Fr access sheath and 12 Fr nephroscope produced a significantly lower pressure at a 60 cm irrigation height than 100 cm (p = 0.0010). IRP was significantly lower with a ureteric catheter in place vs no ureteric catheter at 100 cm (p = 0.0015) and at 60 cm (p = 0.0040).

CONCLUSIONS

Using standard PCNL tract sizes intrarenal pressure varied significantly depending on the height of the irrigation fluid. Mini-PCNL is at higher risk of pathological pressure, however, the use of a ureteric catheter significantly decreased pressure. To maintain safe IRP during PCNL urologists should be aware of these significant variations.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Role of Intrarenal Pressure in Modern Day Endourology (Mini-PCNL and Flexible URS): a Systematic Review of Literature

PURPOSE OF REVIEW

To review the latest evidence about intrarenal pressures (IRPs) generated during flexible ureteroscopy (fURS) and mini percutaneous nephrolithotomy (mPCNL) and present tools and techniques to maintain decreased values.

RECENT FINDING

fURS and PCNL constitute the primary means of stone treatment. New flexible ureterorenoscopes with small diameter and miniaturized PCNL instruments achieve optimal stone-free rates (SFRs) while decreasing invasiveness and morbidity. Nevertheless, endourologists must remain cognizant regarding the dangers of increased IRPs to avoid complications. Current research presents essential information for urologists regarding this topic. During fURS, using a ureteral access sheath (UAS), we avoid extremely high IRPs with all irrigation types. During mPCNL, pressure remains low, mainly using the purging effect or a vacuum-assisted sheath. Devices of intraoperative IRP measurement and intelligent pressure control have proven their feasibility, accuracy and efficacy. These will have an increasing role to play in the future management of stone disease.

Double-sheath vacuum suction versus vacuum-assisted sheath minimally invasive percutaneous nephrolithotomy for management of large renal stones: single-center experience

PURPOSE

To compare double-sheath vacuum suction minimally invasive percutaneous nephrolithotomy (DS-mini-PCNL) with vacuum-assisted mini-PCNL (VS-mini-PCNL) and to better define the potential benefits of DS-mini-PCNL.

METHODS

Between July 2019 and May 2020, 117 patients with large radiopaque renal stones underwent mini-PCNL. Of these, 63 underwent DS-mini-PCNL and 54 underwent VS-mini-PCNL. For VS-mini-PCNL, a F20 Y-shaped sheath was used and the oblique arm of the sheath was connected to the vacuum suction. For DS-mini-PCNL, the oblique arm of a F20 Y-shaped sheath (the outer sheath) and a F16 Y-shaped sheath (the inner sheath) was connected to the perfusion inflow and the vacuum suction, respectively. A 550-μm holmium-YAG laser was used for stone fragmentation.

RESULTS

Compared with VS-mini-PCNL group, DS-mini-PCNL group had significantly shorter operative time (35.78 ± 7.77 min vs. 44.56 ± 13.19 min; P = 0.000) and significantly lower fever rate (1.6% vs. 11.1%; P = 0.048). It was not significantly different between the two groups despite the higher initial stone-free rate seen for DS-mini-PCNL group relative to VS-mini-PCNL group (87.7% vs. 81.5%, P = 0.346). Auxiliary procedure rates were 4.8% (three patients) in DS-mini-PCNL group and 16.7% (nine patients) in VS-mini-PCNL group, with a significant difference (P = 0.034). The difference in the final stone-free rate between the two groups was rendered insignificant (93.8% vs. 89.1%, P = 0.510).

CONCLUSIONS

DS-mini-PCNL is a safe and effective modality for large renal stones, which could increase the efficiency of stone extraction and decrease infectious complications compared with VS-mini-PCNL.

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.