Total tubeless versus standard percutaneous nephrolithotomy: a meta-analysis

Management of urinary stones: state of the art and future perspectives by experts in stone disease

AIM

To present state of the art on the management of urinary stones from a panel of globally recognized urolithiasis experts who met during the Experts in Stone Disease Congress in Valencia in January 2024. Options of treatment: The surgical treatment modalities of renal and ureteral stones are well defined by the guidelines of international societies, although for some index cases more alternative options are possible. For 1.5 cm renal stones, both m-PCNL and RIRS have proven to be valid treatment alternatives with comparable stone-free rates. The m-PCNL has proven to be more cost effective and requires a shorter operative time, while the RIRS has demonstrated lower morbidity in terms of blood loss and shorter recovery times. SWL has proven to be less effective at least for lower calyceal stones but has the highest safety profile. For a 6mm obstructing stone of the pelviureteric junction (PUJ) stone, SWL should be the first choice for a stone less than 1 cm, due to less invasiveness and lower risk of complications although it has a lower stone free-rate. RIRS has advantages in certain conditions such as anticoagulant treatment, obesity, or body deformity. Technical issues of the surgical procedures for stone removal: In patients receiving antithrombotic therapy, SWL, PCN and open surgery are at elevated risk of hemorrhage or perinephric hematoma. URS, is associated with less morbidity in these cases. An individualized combined evaluation of risks of bleeding and thromboembolism should determine the perioperative thromboprophylactic strategy. Pre-interventional urine culture and antibiotic therapy are mandatory although UTI treatment is becoming more challenging due to increasing resistance to routinely applied antibiotics. The use of an intrarenal urine culture and stone culture is recommended to adapt antibiotic therapy in case of postoperative infectious complications. Measurements of temperature and pressure during RIRS are vital for ensuring patient safety and optimizing surgical outcomes although techniques of measurements and methods for data analysis are still to be refined. Ureteral stents were improved by the development of new biomaterials, new coatings, and new stent designs. Topics of current research are the development of drug eluting and bioresorbable stents. Complications of endoscopic treatment: PCNL is considered the most invasive surgical option. Fever and sepsis were observed in 11 and 0.5% and need for transfusion and embolization for bleeding in 7 and 0.4%. Major complications, as colonic, splenic, liver, gall bladder and bowel injuries are quite rare but are associated with significant morbidity. Ureteroscopy causes less complications, although some of them can be severe. They depend on high pressure in the urinary tract (sepsis or renal bleeding) or application of excessive force to the urinary tract (ureteral avulsion or stricture). Diagnostic work up:  Genetic testing consents the diagnosis of monogenetic conditions causing stones. It should be carried out in children and in selected adults. In adults, monogenetic diseases can be diagnosed by systematic genetic testing in no more than 4%, when cystinuria, APRT deficiency, and xanthinuria are excluded. A reliable stone analysis by infrared spectroscopy or X-ray diffraction is mandatory and should be associated to examination of the stone under a stereomicroscope. The analysis of digital images of stones by deep convolutional neural networks in dry laboratory or during endoscopic examination could allow the classification of stones based on their color and texture. Scanning electron microscopy (SEM) in association with energy dispersive spectrometry (EDS) is another fundamental research tool for the study of kidney stones. The combination of metagenomic analysis using Next Generation Sequencing (NGS) techniques and the enhanced quantitative urine culture (EQUC) protocol can be used to evaluate the urobiome of renal stone formers. Twenty-four hour urine analysis has a place during patient evaluation together with repeated measurements of urinary pH with a digital pH meter. Urinary supersaturation is the most comprehensive physicochemical risk factor employed in urolithiasis research. Urinary macromolecules can act as both promoters or inhibitors of stone formation depending on the chemical composition of urine in which they are operating. At the moment, there are no clinical applications of macromolecules in stone management or prophylaxis. Patients should be evaluated for the association with systemic pathologies.

PROPHYLAXIS

Personalized medicine and public health interventions are complementary to prevent stone recurrence. Personalized medicine addresses a small part of stone patients with a high risk of recurrence and systemic complications requiring specific dietary and pharmacological treatment to prevent stone recurrence and complications of associated systemic diseases. The more numerous subjects who form one or a few stones during their entire lifespan should be treated by modifications of diet and lifestyle. Primary prevention by public health interventions is advisable to reduce prevalence of stones in the general population. Renal stone formers at "high-risk" for recurrence need early diagnosis to start specific treatment. Stone analysis allows the identification of most "high-risk" patients forming non-calcium stones: infection stones (struvite), uric acid and urates, cystine and other rare stones (dihydroxyadenine, xanthine). Patients at "high-risk" forming calcium stones require a more difficult diagnosis by clinical and laboratory evaluation. Particularly, patients with cystinuria and primary hyperoxaluria should be actively searched.

FUTURE RESEARCH

Application of Artificial Intelligence are promising for automated identification of ureteral stones on CT imaging, prediction of stone composition and 24-hour urinary risk factors by demographics and clinical parameters, assessment of stone composition by evaluation of endoscopic images and prediction of outcomes of stone treatments. The synergy between urologists, nephrologists, and scientists in basic kidney stone research will enhance the depth and breadth of investigations, leading to a more comprehensive understanding of kidney stone formation.

Comparison of standard percutaneous nephrolithotomy and total tubeless percutaneous nephrolithotomy in the supine position

PURPOSE

To compare the efficacy, safety and advantages of the total tubeless (TT) percutaneous nephrolithotomy (PCNL) and standard PCNL in the supine position.

METHODS

This study was carried out at İzmir Tepecik Health Application and Research Center. A total of 87 patients were examined. Forty-three patients who underwent TT procedure were defined as Group 1, and 44 patients who underwent standard procedure with a nephrostomy tube were defined as Group 2. Two techniques were evaluated with demographic data and outcome parameters. Univariate regression analyses were performed in these data sets for the parameters that predicted the TT procedure.

RESULTS

The demographic data of the groups and all characteristics of the stones were similar. When the results were examined, the stone-free rates detected by non-contrast computed tomography (CT) in the postoperative 1st month were similar between the groups. Complication rates and secondary intervention rates were similar. Operation and fluoroscopy times were shorter in group 1, which were not statistically significant. Postoperative hemoglobin decreased, and creatinine values were similar. In Group 1, mean postoperative visual analog scale (VAS) scores and the percentage of VAS reporting > 5 points for pain level measurement were lower and statistically significant. In the univariate analysis of the factors predicting the TT procedure, no significant results were found in any parameter.

CONCLUSION

Performing TT PCNL in the supine position in selected patients reduces postoperative pain without affecting the complication rates as in prone PCNL. Our study is the first to compare TT and standard PCNL in supine position.

Totally tubeless, tubeless, and tubed percutaneous nephrolithotomy for treating kidney stones

BACKGROUND

Percutaneous nephrolithotomy (PNL) is the standard of care for removing large kidney stones (> 2 cm). Once the procedure is complete, different exiting strategies exist to manage the percutaneous tract opening, including placement of an external nephrostomy tube, placement of an internal ureteral stent, or no external or internal tube. The decision to place or not place a tube is handled differently among clinicians and may affect patient outcomes.

OBJECTIVES

To assess the effects of tubeless PNL (with ureteral stenting), totally tubeless PNL (without ureteral stenting or nephrostomy), and standard PNL (nephrostomy only) for the treatment of kidney stones in adults.

SEARCH METHODS

We performed a systematic literature search in multiple biomedical databases (CENTRAL, MEDLINE, Embase, Web of Science), as well as in two clinical trial registries. We also handsearched reference lists of relevant publications and conference proceedings. We applied no language restrictions. The latest search update was conducted in September 2022.

SELECTION CRITERIA

We included randomized controlled and quasi-randomized controlled trials of adult patients who received tubeless, totally tubeless, or standard PNL for treating kidney stones. We defined tubeless PNL as no nephrostomy tube, but ureteral stenting, while totally tubeless PNL meant no nephrostomy tube or ureteral stenting. Both interventions were compared to standard PNL with placement of a nephrostomy tube (only). We considered access tubes of any sizes. We only considered unilateral PNL with single-tract access. There were no exclusions on stone composition, size, or location.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the literature, extracted data, assessed risk of bias, and rated the certainty of evidence using GRADE. Primary outcomes were severe adverse events and postoperative pain, and secondary outcomes were operating time, length of hospital stay, and stone-free rate. We used the random-effects model for meta-analysis.

MAIN RESULTS

We included 10 studies in the review. Participant age varied among studies, ranging from 20 to 60 years. Detailed information on stone characteristics was rarely presented. Tubeless PNL versus standard PNL We are very uncertain whether there is a difference in severe adverse events (SAEs) between tubeless PNL and standard PNL (risk ratio (RR) 1.53, 95% confidence interval (CI) 0.14 to 16.46; I2 = 42%; 2 studies, 46 participants; very low-certainty evidence). Tubeless PNL may have little to no effect on pain on postoperative day one (mean difference (MD) 0.56 lower, 95% CI 1.34 lower to 0.21 higher; I2 = 84%; 4 studies, 186 participants; low-certainty evidence), and probably results in little to no difference in operating room time (MD 0.40 longer (in minutes), 95% CI 4.82 shorter to 5.62 longer; I2 = 0%; 3 studies, 81 participants; moderate-certainty evidence). Tubeless PNL may reduce length of hospital stay (MD 0.90 shorter, 95% CI 1.45 shorter to 0.35 shorter; I2 = 84%; 6 studies, 238 participants; low-certainty evidence). We are very uncertain of the effect of tubeless PNL on blood transfusions (RR 0.64, 95% CI 0.16 to 2.52; I2 = 0%; 4 studies, 161 participants; very low-certainty evidence), sepsis or fever (RR 0.50, 95% CI 0.05 to 4.75; I2 = not applicable; 2 studies, 82 participants; very low-certainty evidence), or readmissions (RR 1.00, 95% CI 0.07 to 14.21; I2 = not applicable, 1 study, 24 participants; very low-certainty evidence). Totally tubeless versus standard PNL Totally tubeless PNL may result in lower SAE rates (RR 0.49, 95% CI 0.19 to 1.25; I2 = 0%; 2 studies, 174 participants; low-certainty evidence) and pain on postoperative day one (MD 3.60 lower, 95% CI 4.24 lower to 2.96 lower; I2 = Not applicable; 1 study, 50 participants; low-certainty evidence). Totally tubeless PNL may result in little to no difference in operating room time (MD 6.23 shorter (in minutes), 95% CI 14.29 shorter to 1.84 longer; I2 = 72%; 2 studies, 174 participants; moderate-certainty evidence) and sepsis or fever (RR 0.33, 95% CI 0.01 to 7.97; I2 = not applicable; 1 study, 90 participants; low-certainty evidence). Totally tubeless PNL likely shortens the length of hospital stay (MD 1.55 shorter, 95% CI 1.82 shorter to 1.29 shorter; I2 = 0%; 4 studies, 274 participants; moderate-certainty evidence). We are very uncertain of the effect of totally tubeless PNL on blood transfusions (RR 0.62, 95% CI 0.26 to 1.48; I2 = 0%; 4 studies, 274 participants; very low-certainty evidence) or readmissions (RR not estimable, 95% CI not estimable; I2 = not applicable; 1 study, 50 participants; very low-certainty evidence). We found no studies comparing tubeless mini versus standard mini-PNL or totally tubeless mini versus standard mini-PNL.

AUTHORS' CONCLUSIONS

When comparing tubeless to standard PNL with regard to the predefined primary outcomes of this review, there may be little difference in early postoperative pain, while we are very uncertain of the effect on SAEs. People treated with tubeless PNL may benefit from a reduced length of stay compared to standard PNL. When comparing totally tubeless to standard PNL, early postoperative pain and severe adverse events may be reduced with totally tubeless PNL. The certainty of evidence by outcome was mostly very low (range: moderate to very low) for the comparison of tubeless to standard PNL and low (range: moderate to very low) for the comparison of totally tubeless to standard PNL. The most common reasons for downgrading the certainty of the evidence were study limitations, inconsistency, and imprecision. We did not find randomized trial evidence for other comparisons. Overall, further and higher-quality studies are needed to inform clinical practice.

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.

A prospective, single-centered, cohort study comparing the treatment of renal stones by following PCNL types: Standard, tubeless & totally tubeless

Introduction

Renal stones are a frequent cause of morbidity globally. The number of lumbotomies performed for benign lithiasis has been greatly decreased with the usage of Percutaneous Nephrolithotomy (PCNL). Further development is aimed at reducing tract size, leading to numerous advanced minimally invasive PCNL procedures like mini-PERC, ultra-mini-PERC, and micro-PERC. The aim of this study was to evaluate whether tubeless or totally tubeless PCNL is the safest and most efficient, less morbid management technique for renal stones compared to the standard PCNL with a nephrostomy tube.

Methodology

This is a comparative, prospective, single-centered, cohort study that took place between August 2015 and January 2018 in the Urology department of Benazir Bhutto Hospital in Rawalpindi, Pakistan. 218 patients having single/multiple stones of variable sizes were enrolled in the study. Participants were stratified into three groups; Group A: Standard PCNL treatment; Group B: Tubeless PCNL treatment; Group C Totally Tubeless treatment. Mean operation time (±SD) and stone-free rates were our primary outcomes. The rate of complications during and post-operative complications were our secondary outcomes.

Results

A total of 181 patients were included in our study. A decreasing trend can be seen in mean operation time as we move from Group A to Group C (p = 0.000). The rate of problems during operation in each group was highest (45.8%) in Group A, much lesser problems in Group C (13.3%), and least problems in Group B (8.1%) (p = 0.000). The postoperative complication rate was again the highest in Group A (30.5%), low in Group C (8.3%), and extremely low in Group B (1.6%)

Conclusion

Tubeless PCNL proved to be the safest and most effective when compared to standard and totally tubeless PCNL procedures. It also showed the highest stone-free rates and least ‘unsatisfactory’ results amongst all the groups. Conclusively, it should be performed in routine preferably.

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In terms of safety and efficacy, tubeless PCNL outperformed both regular and completely tubeless PCNL.

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The Tubeless PCNL is much superior than other techniques of PCNL.

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Aftercare and difficulties during surgery are virtually nonexistent with tubeless PCNL.

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Stone-free rates were also the highest and the least “unsatisfactory” across all groups. Finally, it's best if it's done on a regular basis.

Innovations in urolithiasis management

PURPOSE OF REVIEW

This review provides a forecast about ongoing developments in the management of urolithiasis with a potential to challenge the current standard of care. We therefore emphasized innovative technology, which might be considered still experimental in the daily clinic or needs further clinical validation, but harbors the great potential to become a game changer for future stone management.

RECENT FINDINGS

Especially in the endoscopic stone treatment, we observed a multitude of groundbreaking technical innovations, which changed our treatment algorithms over the last decades. Some of this technology already found its way into daily practice. Others like artificial intelligence, burst wave lithotripsy, smart laser systems or gene therapy may not be standardized yet, but have the potential to further revolutionize current practice. Besides those technical features, we included innovations in prevention and diagnostics, as well as patient expectations and patient satisfaction into the analysis. A proper metaphylaxis and patient communication seems to be essential for a long-lasting treatment success.

SUMMARY

The combination of technical innovations, improved stone metaphylaxis and proper patient communication presents the cornerstone of future kidney stone management.

The feasibility of multiple-tract mini-percutaneous nephrolithotomy as an overnight surgery for the treatment of complex kidney stones

To demonstrate the feasibility of applying multiple-tract percutaneous nephrolithotomy (PCNL) as an overnight surgery for treatment of complex kidney stones. We reviewed a prospectively collected database of all multiple-tract PCNL planned as overnight surgery performed by a single surgeon since 2018. A clinical pathway including the removal of nephrostomy tube and discharge on the morning after surgery was carried out. A definition for tube removal was outlined. Ability to adhere to the pathway and achieving the described parameters and whether any resulting complications occurred were determined. A total of 136 consecutive patients were enrolled with mean stone burden of 960.5 mm² and 5.1 cm. Mean operative time was 71.7 ± 30.7 min. The average hemoglobin drop was 17.6 ± 12.2 g/L, and the incidence of drop > 25 g/L was 21.9%. Overall, 125 patients (91.9%) but 11 patients were discharge on postoperative day 1. One case required readmission. Among the 11 patients, 7 patients (5.1%) underwent a delayed tube removal (≥ 2 days) and 4 patients underwent complications after next-day nephrostomy tube removal, including renal colic (2 cases), hydrothorax (1 case), and fever (1 case). Postoperative fever or severe hematuria was the major reason for delayed nephrostomy tube removal. The total complication rate was 8.8% (n = 12). Multiple-tract PCNL as an overnight surgery can be safely performed by experienced surgeons in most patients. An early nephrostomy tube removal could be achieved in nearly 95% patients.