Purpose This Guideline is intended to provide a clinical framework for the surgical management of patients with kidney and/or ureteral stones. The summary presented herein represents Part I of the ...two-part series dedicated to Surgical Management of Stones: American Urological Association/Endourological Society Guideline. Please refer to Part II for an in-depth discussion of patients presenting with ureteral or renal stones. Materials and Methods A systematic review of the literature (search dates 1/1/1985 to 5/31/15) was conducted to identify peer-reviewed studies relevant to the surgical management of stones. The review yielded an evidence base of 1,911 articles after application of inclusion/exclusion criteria. These publications were used to create the Guideline statements. Evidence-based statements of Strong, Moderate, or Conditional Recommendation were developed based on benefits and risks/burdens to patients. Additional directives are provided as Clinical Principles and Expert Opinions when insufficient evidence existed. Results The Panel identified 12 adult Index Patients to represent the most common cases seen in clinical practice. Three additional Index Patients were also created to describe pediatric and pregnant patients with such stones. With these patients in mind, Guideline statements were developed to aid the clinician in identifying optimal management. Conclusions Proper treatment selection, which is directed by patient- and stone-specific factors, remains the greatest predictor of successful treatment outcomes. This Guideline is intended for use in conjunction with the individual patient’s treatment goals. In all cases, patient preferences and personal goals should be considered when choosing a management strategy.
Abstract Context Percutaneous nephrolithotomy (PCNL) is the surgical standard for treating large or complex renal stones. Since its inception, the technique of PCNL has undergone many modifications. ...Objective To perform a collaborative review on the latest evidence related to outcomes and innovations in the practice of PCNL since 2000. Evidence acquisition A literature review was performed using the PubMed database between 2000 and July 2015, restricted to human species, adults, and the English language. The Medline search used a strategy including the following keywords: percutaneous nephrolithotomy, PNL, advances, trends, technique , and the Medical Subject Headings term percutaneous nephrostomy. Evidence synthesis Population-based studies have now provided a wealth of information regarding patient outcomes following PCNL. The complexity of the stone treated can be quantified using a variety of validated nephrolithometry classification systems. Increasing familiarity with the supine approach to PCNL has enabled simultaneous combined retrograde and antegrade surgery. Advances such as endoscopic guided percutaneous access may help urologists achieve access with less morbidity. Increasing miniaturization of equipment has led to the development of mini, micro, and ultramini techniques. The tubeless method of PCNL is now accepted practice with good evidence of safety in appropriately selected patients. Conclusions Modern-day PCNL allows personalized stone management tailored to individual patient and surgeon factors. Future studies should continue to refine methods to assess complexity and safety and to determine consensus on the use of miniaturized PCNL. Patient summary Modern-day percutaneous nephrolithotomy has transformed from an operation traditionally undertaken in one position, using one access method with one set of instrumentation and one surgeon, to one with a variety of options at each step.
Purpose This Guideline is intended to provide a clinical framework for the surgical management of patients with kidney and/or ureteral stones. The summary presented herein represents Part II of the ...two-part series dedicated to Surgical Management of Stones: American Urological Association/Endourological Society Guideline. Please refer to Part I for introductory information and a discussion of pre-operative imaging and special cases. Materials and Methods A systematic review of the literature (search dates 1/1/1985 to 5/31/2015) was conducted to identify peer-reviewed studies relevant to the surgical management of stones. The review yielded an evidence base of 1,911 articles after application of inclusion/exclusion criteria. These publications were used to create the Guideline statements. Evidence-based statements of Strong, Moderate, or Conditional Recommendation were developed based on benefits and risks/burdens to patients. Additional directives are provided as Clinical Principles and Expert Opinions when insufficient evidence existed. Results The Panel identified 12 adult Index Patients to represent the most common cases seen in clinical practice. Three additional Index Patients were also created to describe the more commonly encountered special cases, including pediatric and pregnant patients. With these patients in mind, Guideline statements were developed to aid the clinician in identifying optimal management. Conclusions Proper treatment selection, which is directed by patient- and stone-specific factors, remains the greatest predictor of successful treatment outcomes. This Guideline is intended for use in conjunction with the individual patient’s treatment goals. In all cases, patient preferences and personal goals should be considered when choosing a management strategy.
Purpose This technology assessment addresses the optimal use of imaging in the evaluation and treatment of patients with suspected or documented ureteral stones. Materials and Methods A comprehensive ...literature search addressing 4 guiding questions was performed for full text in English articles published between January 1990 and July 2011. The search focused on major subtopics associated with the imaging of ureteral calculi, and included specific imaging modalities used in the diagnosis and management of ureteral calculous disease such as unenhanced (noncontrast) computerized tomography, conventional radiography, ultrasound, excretory urography, magnetic resonance imaging and nuclear medicine studies. Protocols (in the form of decision tree algorithms) were developed based on this literature review and in some instances on panel opinion. The 4 questions addressed were 1) What imaging study should be performed for suspected ureteral calculous disease? 2) What information should be obtained? 3) After diagnosis of a ureteral calculus, what followup imaging should be used? 4) After treatment of a ureteral calculus, what followup imaging studies should be obtained? Results Based on these protocols, noncontrast computerized tomography is recommended to establish the diagnosis in most cases, with a low energy protocol advocated if body habitus is favorable. Conventional radiography and ultrasound are endorsed for monitoring the passage of most radiopaque stones as well as for most patients undergoing stone removal. Other studies may be indicated based on imaging findings, and patient, stone and clinical factors. Conclusions The protocols generated assist the clinician in establishing the diagnosis of ureteral calculous disease, monitoring stone passage and following patients after treatment. The protocols take into account not only clinical effectiveness but also cost-effectiveness and risk/harm associated with the various imaging modalities.
Percutaneous nephrolithotomy is a common surgical treatment for large and complex stones within the intrarenal collecting system. A wide variety of complications can result from this procedure, ...including bleeding, injury to surrounding structures, infection, positioning-related injuries, thromboembolic disease, and even death. Knowledge of the different types of complications can be useful in order to prevent, diagnose, and treat these problems if they occur. This review describes the diversity of complications with the goal of improving their avoidance and treatment.
Purpose The purpose of this guideline is to provide a clinical framework for the diagnosis, prevention and follow-up of adult patients with kidney stones based on the best available published ...literature. Materials and Methods The primary source of evidence for this guideline was the systematic review conducted by the Agency for Healthcare Research and Quality on recurrent nephrolithiasis in adults. To augment and broaden the body of evidence in the AHRQ report, the AUA conducted supplementary searches for articles published from 2007 through 2012 that were systematically reviewed using a methodology developed a priori . In total, these sources yielded 46 studies that were used to form evidence-based guideline statements. In the absence of sufficient evidence, additional statements were developed as Clinical Principles and Expert Opinions. Results Guideline statements were created to inform clinicians regarding the use of a screening evaluation for first-time and recurrent stone formers, the appropriate initiation of a metabolic evaluation in select patients and recommendations for the initiation and follow-up of medication and/or dietary measures in specific patients. Conclusions A variety of medications and dietary measures have been evaluated with greater or less rigor for their efficacy in reducing recurrence rates in stone formers. The guideline statements offered in this document provide a simple, evidence-based approach to identify high-risk or interested stone-forming patients for whom medical and dietary therapy based on metabolic testing and close follow-up is likely to be effective in reducing stone recurrence.
To more clearly define the efficiency and potential benefits of variable pulse-width laser technology for ureteroscopic lithotripsy, we performed comparative in vitro evaluations assessing stone ...comminution, laser fiber tip degradation, and stone retropulsion.
All experiments were conducted using a Swiss LaserClast Holmium:YAG laser (Electro Medical Systems, Nyon, Switzerland) with adjustable pulse duration (300 µs-1500 µs). To assess comminution efficiency and fiber tip degradation, a "dusting" model was employed; the laser fiber tip was moved by a 3-dimensional positioning system in a spiral motion across a flat BegoStone surface submerged in water. Comminution efficiency was measured as the loss of stone mass while fiber tip degradation was measured simultaneously. The same laser and fiber were used in a pendulum model to measure stone retropulsion with a high-speed resolution camera.
In our dusting model, comminution was significantly greater at high energy (2 J/5 Hz). At the high energy setting, comminution was significantly greater with long pulse duration than short pulse, although this difference was not seen at the high frequency setting (1 J/10 Hz). Tip degradation was increased at high energy settings and was even more pronounced with short pulse duration than long pulse. Short pulse duration caused far more retropulsion than the long pulse setting.
In an in vitro dusting model, a longer laser pulse duration provides effective stone comminution with the advantage of reducing laser fiber tip degradation and stone retropulsion.
Ureteroscopic laser lithotripsy requires irrigation for adequate visualization and temperature control during treatment of ureteral stones. However, there are little data on how different irrigation ...and laser settings affect the ureteral wall and surrounding tissues. This effect has become an important consideration with the advent of high-powered lasers. We therefore evaluated the effect of laser settings and irrigation flow on ureteral temperature in an in vitro setting.
To mimic ureteroscopic laser lithotripsy, we simulated clinically relevant irrigation flow rates and fired a Holmium:Yttrium-aluminum-garnet (Ho:YAG) laser while monitoring "intraureteral" temperature. The probe tip of a thermometer was placed 1 mm from the tip of a 200 μm laser fiber, which was fired for 60 seconds at 0.2 J/50 Hz, 0.6 J/6 Hz, 0.8 J/8 Hz, 1 J/10 Hz, and 1 J/20 Hz within a tubing system that allowed for specified room temperature flow rates (100, 50, and 0 mL/minute). We recorded temperatures every 5 seconds. The maximum temperature was noted, and each laser/flow trial was duplicated. Averaged maximum temperatures were compared using analysis of variance across irrigation settings.
At 100 cc/minute, only the 1 J/20 Hz laser setting produced a significantly higher maximum temperature (p < 0.01), although this finding was not clinically significant at a maximum of 30.7°C. At a lower irrigation rate of 50 cc/minute, the 1 J/20 Hz setting was again the only significantly higher maximum temperature (p < 0.05), although this temperature crossed the toxic threshold at a maximum of 43.4°C. With no flow, all maximum temperatures reached over 43°C, with 0.8 J/8 Hz, 1 J/10 Hz, and 1 J/20 Hz each statistically higher than the lower-energy settings (p < 0.05). The maximum temperature at 1 J/20 Hz with no irrigation was over 100°C.
Despite increasing laser settings, adequate irrigation can maintain relatively stable temperatures within an in vitro ureteral system. As irrigation rates decrease, even lower power laser settings produce a clinically significant increase in maximum temperature, potentially causing ureteral tissue injury.
Objectives
To set out the second in a series of guidelines on the treatment of urolithiasis by the International Alliance of Urolithiasis that concerns retrograde intrarenal surgery (RIRS), with the ...aim of providing a clinical framework for urologists performing RIRS.
Materials and Methods
After a comprehensive search of RIRS‐related literature published between 1 January 1964 and 1 October 2021 from the PubMed database, systematic review and assessment were performed to inform a series of recommendations, which were graded using modified GRADE methodology. Additionally, quality of evidence was classified using a modification of the Oxford Centre for Evidence‐Based Medicine Levels of Evidence system. Finally, related comments were provided.
Results
A total of 36 recommendations were developed and graded that covered the following topics: indications and contraindications; preoperative imaging; preoperative ureteric stenting; preoperative medications; peri‐operative antibiotics; management of antithrombotic therapy; anaesthesia; patient positioning; equipment; lithotripsy; exit strategy; and complications.
Conclusion
The series of recommendations regarding RIRS, along with the related commentary and supporting documentation, offered here should help provide safe and effective performance of RIRS.
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