Comparison of the Prone Split-Leg Position with the Traditional Prone Position in Percutaneous Nephrolithotomy: A Propensity Score-Matching Study

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.

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.

Endoscopic combined intrarenal surgery in prone split-leg and inclined supine positions to treat renal cast and multiple calyx stones

This Invited Commentary discusses the following article:

Mulay A, Mane D, Mhaske S, Shah AS, Krishnappa D, Sabale V. Supine versus prone percutaneous nephrolithotomy for renal calculi: Our experience. Curr Urol 2022;16 (1):25-29. doi: 10.1097/CU9.0000000000000076.