Current Practice Patterns in the Management of Upper Urinary Tract Calculi in the North Central United States

Extracorporeal shock wave lithotripsy: Prematurely falling out of favour? A 7 year retrospective study from an Australian high-volume centre

Objectives

The aim of this study is to audit 7 years of data with a 3 year follow up from a high-volume stone centre performing extracorporeal shock wave lithotripsy (ESWL) to evaluate efficacy in stone clearance compared to existing knowledge and understand reasons for this performance.

Methods

Patients who received ESWL treatment for renal or proximal ureteric stones at a single centre between January 2012 and January 2019 (to allow minimum 3 year follow up) were retrieved. A retrospective analysis was performed cross referencing for stone size, location, treatment and need for further procedures. Ethical approval was granted through Metro North HHS HREC, Queensland, Australia.

Results

A total of 1930 patients met inclusion criteria. Fifty-seven percent (n = 1100) underwent left-sided ESWL, compared to 43% (n = 830) on the right. Stone size and location were both statistically significant to treatment outcome. Small stones (<1 cm) had an overall clearance rate of 81.9%, medium stones (1-2 cm) had a clearance rate of 60.6% and stones (>2 cm) had a clearance rate of 31.3%. Small stones in an upper calyx had the highest clearance rate (87.5%, n = 120). Allowing for two procedures, 89% of stones were treated successfully.

Conclusion

ESWL remains a legitimate option for the treatment of small and medium sized renal calculi. ESWL stone clearance rates at our centre are higher than published elsewhere and serve as proof to its efficacy. X-ray imaging on the day of the procedure, heavy consultant input and frequent intra-operative imaging are cited as key reasons for success. Further research is warranted to elucidate factors affecting stone clearance rate and to enable more standardised outcomes. Further investment may be required into ESWL provisions in most Australian states and especially in Queensland to enable its continued use in contrast to developing endourological techniques.

Use of artificial stones in training and laboratory studies, have we found the right material? Outcomes of a systematic review from the European School of Urology

Objective

In this review, we investigated the current literature to find out which artificial stones (AS) are available in endourology, and in which experimental and training schemes they are used.

Materials and Methods

A systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Twenty-one out of 346 studies met our inclusion criteria and are presented in the current review. The inclusion criteria were the existence of AS and their use for laboratory and training studies.

Results

There is a wide variety of materials used for the creation of AS. BegoStone powder (BEGO USA, Lincoln, Rhode Island) and plaster of Paris™ were used in most of the studies. In addition, Ultracal-30 (U. S. Gypsum, Chicago, IL) was also used. Other materials that were used as phantoms were AS created from plaster (Limbs and Things, UK), standardized artificial polygonal stone material (Chaton 1028, PP13, Jet 280; Swarovski), model stones consisting of spheres of activated aluminum (BASF SE, Ludwigshafen am Rhein, Deutschland), Orthoprint (Zhermack, Badia Polesine, Italy), and a combination of plaster of Paris, Portland cement, and Velmix (calcium sulfate powder). Many experimental settings have been conducted with the use of AS. Our research demonstrated nine studies regarding testing and comparison of holmium: yttrium-aluminum-garnet laser devices, techniques, and settings. Six studies were about extracorporeal shock wave lithotripsy testing and settings. Three experiments looked into treatment with percutaneous nephrolithotomy. Additionally, one study each investigated imaging perioperatively for endourological interventions, stone bacterial burden, and obstructive uropathy.

Conclusion

AS have been used in a plethora of laboratory experimental studies. Independent of their similarity to real urinary tract stones, they present a tremendous potential for testing and training for endourological interventions.

Comparison of super-mini versus mini percutaneous nephrolithotomy for the treatment of upper urinary tract stones in children: a single centre experience

PURPOSE

The efficacy and safety of super-mini percutaneous nephrolithotomy (SMP, 14 Fr) was compared with mini percutaneous nephrolithotomy (MPCNL, 16 Fr) for the treatment of upper urinary tract stones in children (< 14 years old).

METHODS

Clinical data of 133 paediatric patients with upper urinary tract stones treated with SMP or MPCNL between May 2012 and May 2019 were retrospectively analysed. The patients were divided into the SMP and MPCNL groups. Age, height, weight, stone size, operation time, stone-free rate (SFR), postoperative complications, tubeless rate, and length of postoperative hospital stay (LOS) were compared.

RESULTS

There were 66 patients (49.6%) in the SMP and 67 patients (50.4%) in the MPCNL group. No significant difference in the median age, weight, height and operation time, and SFR existed between the patients of the two groups. Larger stones were removed via SMP compared to those removed with MPCNL (2.0 vs. 1.5 cm, P = 0.001). LOS for SMP patients was significantly lower than that for the MPCNL patients (2 and 6 days, respectively, P < 0.0001). The tubeless rate for SMP was significantly higher than that for MPCNL (100% vs. 0%, P < 0.0001). Total complication rate of MPCNL was significantly higher than that of SMP (25.3% vs. 7.5%, P = 0.006). No patient required blood transfusion, and septicaemia, and other serious complications did not occur.

CONCLUSION

SMP is more effective than MPCNL for treating middle-sized upper urinary tract stones in children, and is associated with a shorter LOS and a higher tubeless rate.

Fluoroscopy-use during ureterorenoscopy: are urologists concerned about radiation exposure? A nationwide survey in Belgium and The Netherlands

INTRODUCTION

To evaluate the use and awareness of radiation during URS among Belgian and Dutch urologists.

MATERIAL AND METHODS

An online questionnaire was send to all members of the Belgian and Dutch Association of Urology.

RESULTS

170 urologists finished the complete questionnaire. 10% of the respondents are not familiar with the ALARA-principle. 29% starts with a KUB and 48% makes an XRPG at the beginning of the procedure. 85% uses fluoroscopy to place a wire or ureteral access sheet, 18% during stone treatment, 59% to screen for missed stones or calyces, 90% to place a JJ-stent or ureter-catheter and 23% to check for extravasation. 82% do not document radiation data. 51% does not wear a dosimeter during fluoroscopy. Almost all wear a lead apron during fluoroscopy, 47% uses additional thyroid shields and only 4% uses lead glasses. 88% intentionally reduces fluoroscopy time, 75% reduces the exposed area with a diaphragm, 72% brings the radiation source close to the patient and 44% uses pulsed fluoroscopy.

CONCLUSION

There is a wide variety in the use and awareness of radiation during URS. To further reduce radiation and its negative effect for patients and medical staff, awareness about radiation safety should increase among urologists.

Obstructive Kidney Disease

Obstructive kidney disease is a common urologic diagnosis and includes kidney stones, polycystic kidney disease, and renal artery stenosis. Kidney stones are a common emergency department admission in the United States. Men are affected more than women. Polycystic kidney disease is a genetic renal disease that may not reveal symptoms until an individual reaches age 30 years. Renal artery stenosis contributes to decreased perfusion to the kidneys, which contributes to hypertension and end-stage renal disease.

Limited sensitivity and size over measurements of ultrasound affect medical decisions for ureteral stone compared to non-contrasted computed tomography

PURPOSE

To evaluate the limited sensitivity and size over measurements of ultrasound (US) for ureteral stone, and demonstrate how this influenced medical decisions.

PATIENTS AND METHODS

Retrospectively, we analyzed the data of patients with ureterolithiasis estimated by US and non-contrasted computed tomography (NCCT) within 48 h at our institution from January 1st 2014 to June 1st 2017. Stone size was grouped by the longest axis diameter on NCCT: < 5, 5-10, and > 10 mm. Then, US and NCCT results were compared for the sensitivity and measurements.

RESULTS

A total of 614 cases of ureterolithiasis were visible on NCCT. The sensitivity of US for ureterolithiasis < 5, 5-10, and > 10 mm were 63.49, 79.06, and 84.67%, respectively (P = 0.001). US overestimated the size in 63.49 and 50.54% of patients with ureterolithiasis < 5 and 5-10 mm compared to NCCT, respectively (P < 0.001). Under the assumptions that patients with ureteral stone < 5, 5-10, and > 10 mm would be simply observed, received medical expulsive therapy (MET), and surgical interventions, 20.94 and 15.33% of patients with stone sized 5-10 and > 10 mm might be improperly observed due to negative US reports. Besides, 63.49 and 50.54% of cases with stone < 5 and 5-10 mm might receive more aggressive interventions ascribed to over measurements of US.

CONCLUSIONS

Limited sensitivity and size over measurements of US might significantly influence medical decisions for ureteral stone. Inaccurate evaluation of US should be taken in consideration for appropriate counseling options.

Conversion from Cystine to Noncystine Stones: Incidence and Associated Factors

PURPOSE

Patients with cystinuria are often treated with medical alkalization and shock wave lithotripsy, although each treatment is hypothesized to increase the risk of calcium phosphate stones. We performed a multicenter retrospective review to evaluate whether stones of another composition develop in patients with cystinuria and with what frequency.

MATERIALS AND METHODS

We retrospectively reviewed the records of a multi-institutional cohort of patients with cystinuria. We assessed medications, stone analyses, 24-hour urinalyses and types of procedures. We compared patients who formed only cystine stones vs those with noncystine stones.

RESULTS

We identified 125 patients from a total of 5 institutions who were followed a mean of 5.2 years (range 0 to 26). Stones with noncystine components were submitted by 37 patients (29.6%). Potassium citrate medication was not associated with a noncystine composition (p = 0.1877). Regarding surgical management 18 patients (13%) underwent at least 1 shock wave lithotripsy session (range 0 to 9) and 79 (63%) underwent percutaneous nephrolithotomy at least once (range 0 to 10). When stratified based on pure cystine vs converted stones, the average total number of shock wave lithotripsy and percutaneous nephrolithotomy procedures was higher in the group with cystine and subsequent noncystine stone compositions (0.94 vs 0.10, p <0.0001, and 1.7 vs 1.5, p = 0.0053, respectively). On logistic regression male gender (OR 3.1, p = 0.0280) and the number of shock wave lithotripsy sessions (OR 3.0, p = 0.0170) were associated with an increased likelihood of the development of stones with a noncystine composition.

CONCLUSIONS

Stones with noncystine components develop in more than 25% of patients with cystinuria, underscoring the importance of continued stone analysis. In this study prior shock wave lithotripsy was associated with conversion to a noncystine stone composition while urinary alkalization therapy was not associated.

Italian endourological panorama: results from a national survey

Introduction

The purpose of this survey was to explore the dissemination of flexible ureteroscopy (fURS), shockwave lithotripsy (SWL) and percutaneous nephrolithotomy (PCNL) in the Italian urological community and to know the real availability of the complex endourological armamentarium all over the country.

Materials and methods

An online questionnaire characterizing the case volume/year of upper urinary tract stone treatment and the availability of flexible ureteroscopes (FUs) armamentarium was sent to all urological Italian centers.

Results

The survey was sent to 294 urological centers and 146 responded (49.7%). The case volume/year of fURS was the following: <20 cases in 20 centers (13.7%); 20-50 cases in 40 centers (27.4%), >50- <100 cases in 55 centers (37.8%) and >100 cases in 28 centers (19.2%). The case volume/year of SWL was the following: <50 cases in 18 centers (12.3%); >50- <200 cases in 56 centers (36.4%) and >200 cases in 35 centers (24%). In 37 centers (25.3%) SWL was not utilized at all. The case volume/year of PCNL was the following: <10 cases in 20 centers (14%); >10 - <30 cases in 55 centers (30%), >30- < 50 cases in 33 centers(23%), >50- <100 cases in 13 centers (9%) and >100 procedures in 2 centers (1%). However, 24 centers (16%) did not perform any PCNL procedure.Four centers (3%) did not have any FU at the moment of the survey. The availability of FUs was as follows: 1 FU in 21 (14%) centers, 2 FUs in 61 (42%) centers, 3 FUs in 29 (20%) centers, 4 FUs in 13 (9%) centers and ≥5 FUs in 16 (9%) centers. Only 82 (56%) centers had all of their FUs in working condition.

Conclusions

This survey succeeded in providing a complete overview on the Italian endourological panorama.

The Accuracy and Prognostic Value of Point-of-care Ultrasound for Nephrolithiasis in the Emergency Department: A Systematic Review and Meta-analysis

INTRODUCTION

Point-of-care ultrasound (POCUS) has been suggested as an initial investigation in the management of renal colic. Our objectives were: 1) to determine the accuracy of POCUS for the diagnosis of nephrolithiasis and 2) to assess its prognostic value in the management of renal colic.

METHODS

The review protocol was registered to the PROSPERO database (CRD42016035331). An electronic database search of MEDLINE, Embase, and PubMed was conducted utilizing subject headings, keywords, and synonyms that address our research question. Bibliographies of included studies and narrative reviews were manually examined. Studies of adult emergency department patients with renal colic symptoms were included. Any degree of hydronephrosis was considered a positive POCUS finding. Accepted criterion standards were computed tomography evidence of renal stone or hydronephrosis, direct stone visualization, or surgical findings. Screening of abstracts, quality assessment with the QUADAS-2 instrument, and data extraction were performed by two reviewers, with discrepancies resolved by consensus with a third reviewer. Test performance was assessed by pooled sensitivity and specificity, calculated likelihood ratios, and a summary receiver operator curve (SROC). The secondary objective of prognostic value was reported as a narrative summary.

RESULTS

The electronic search yielded 627 unique titles. After relevance screening, 26 papers underwent full-text review, and nine articles met all inclusion criteria. Of these, five high-quality studies (N = 1,773) were included in the meta-analysis for diagnostic accuracy and the remaining yielded data on prognostic value. The pooled results for sensitivity and specificity were 70.2% (95% confidence interval [CI] = 67.1%-73.2%) and 75.4% (95% CI = 72.5%-78.2%), respectively. The calculated positive and negative likelihood ratios were 2.85 and 0.39. The SROC generated did not show evidence of a threshold effect. Two of the studies in the meta-analysis found that the finding of moderate or greater hydronephrosis yielded a specificity of 94.4% (95% CI = 92.7%-95.8%). Four studies examining prognostic value noted a higher likelihood of a large stone when positive POCUS findings were present. The largest randomized trial showed lower cumulative radiation exposure and no increase in adverse events in those who received POCUS investigation as the initial renal colic investigation.

CONCLUSION

Point-of-care ultrasound has modest diagnostic accuracy for diagnosing nephrolithiasis. The finding of moderate or severe hydronephrosis is highly specific for the presence of any stone, and the presence of any hydronephrosis is suggestive of a larger (>5 mm) stone in those presenting with renal colic.

Persistence of Open Stone Surgery in the United States in the 21st Century

INTRODUCTION

In the era of minimally invasive surgery, endoscopic and percutaneous interventions for urinary tract stones have become a mainstay, and the need for open stone surgery (OSS) has decreased. We sought to determine the contemporary incidence of OSS among urologists in the United States.

METHODS

Case logs submitted for certification to the American Board of Urology from 2005 to 2015 were queried for Current Procedural Terminology codes relevant to OSS. Cases were analyzed for the associated practice type, practice area population, geographic region, provider subspecialty, and certifying status of the reporting urologist.

RESULTS

A total of 334 cases of OSS were identified, with 73.4% performed by urologists self-identified as generalists. The most common subspecialists performing OSS were endourologists (12.3%). Most cases were done in the private practice setting (80.4%), and in practice areas with populations exceeding 1,000,000 (43.2%). OSS was more commonly reported by urologists applying for recertification than initial certification. Thirty open stone cases were reported each year on average, and there was no decrease in stone cases over time based on linear regression analysis (R² = 0.06). OSS was most commonly performed in the Western Section of the American Urological Association (AUA) (25.1%) and least commonly performed in the Northeastern Section (1.5%). A chi-square analysis was performed, and the Western Section had a significantly higher number of OSSs than expected as its urologists represent only 17% of the total AUA membership (p < 0.01). The Northeastern Section comprises 7% of the AUA membership but only performed 1.5% of OSSs that were significantly lower than expected (p < 0.001).

CONCLUSIONS

Domestic performance of OSS remains stable. It is unclear as to whether the majority of these cases could be served by less-invasive technologies or whether the volume represents a true nadir. Future work may be warranted to assess attitudes, training, and feasibility of minimally invasive stone management in areas where OSS is most common.

Burden of Urolithiasis: Trends in Prevalence, Treatments, and Costs

CONTEXT

The recent evolution of management options for urolithiasis has presented a unique dilemma for the modern urologist. A comprehensive understanding of epidemiological trends along with current provider preferences in treating urinary stones would be beneficial.

OBJECTIVE

To review trends in the prevalence, treatments, and costs of urolithiasis worldwide.

EVIDENCE ACQUISITION

A literature review was performed using the MEDLINE database, the Cochrane Library Central search facility, Web of Science, and Google Scholar between 1986 and 2016. Keywords used for the search were "urolithiasis" and "prevalence; treatment; and cost".

EVIDENCE SYNTHESIS

The incidence and prevalence of urinary stones are rising around the world, including regions that have historically had low rates of urolithiasis. Common theories explaining this trend involve climate warming, dietary changes, and obesity. Shockwave lithotripsy (SWL) has been the preferred mode of treatment since its introduction in the 1980s. However, ureteroscopy (URS) has become increasingly popular for small stones regardless of location because of lower recurrence rates and costs. Developing countries have been slower to adopt URS technology and continue to use percutaneous nephrolithotomy at a steady rate.

CONCLUSIONS

URS has recently challenged SWL as the treatment modality preferred for small upper urinary tract stones. In some cases it is less expensive but still highly effective. As the burden of stone disease increases worldwide, appropriate selection of stone removal therapies will continue to play an important role and will thus require further investigation.

PATIENT SUMMARY

Urinary stones are becoming more prevalent. Recent advances in technology have improved the management of this disease and have decreased costs.

Miniperc vs Shockwave Lithotripsy for Average-Sized, Radiopaque Lower Pole Calculi: A Prospective Randomized Study

Introduction: To detect safety and feasibility of miniperc and extracorporeal shockwave lithotripsy (SWL) for treatment of average-sized (1-2 cm), radiopaque lower pole calculi in a prospective randomized manner. Patients and Methods: In the period from January 2014 to June 2015, 150 patients were attached to this study with single lower pole radiopaque stone ranging from 10 to 20 mm. Patients were divided randomly into two groups using computer-generated randomization in an equal manner. First group patients were subjected to miniperc procedure, while second group patients underwent SWL. Patient's characters, stones' characters, fluoroscopic time, operative time, blood transfusion, hospital stay, retreatment, auxiliary procedure (AP), and complications using modified Clavien grading are tabulated and analyzed. Results: This study included two equal groups with 75 patients in each group. With regard to age (37.75 ± 11.25 vs 40.55 ± 10.55), body mass index (26.92 ± 2.26 vs 27.29 ± 2.87), and stone size (1.55 ± 0.28 vs 1.57 ± 0.26), there was no significant statistical difference in both groups. Stone-free rate (SFR) (76% vs 96%), operative time (44.81 ± 7.06 vs 93.37 ± 12.29 minutes), fluoroscopy time (53 ± 2.45 vs 180 ± 7.31 seconds), hospital stay (5.72 ± 1.01 vs 45.19 ± 8.48 hour), and blood transfusion were significantly more in the miniperc group. Retreatment rate (45.3% vs 2.7%) and AP (24% vs 4%) were significantly greater in the SWL group. Conclusion: SWL is less invasive than percutaneous stone removal, but it is also less effective for lower pole radiopaque calculi. Miniperc has better SFR and lower auxiliary and retreatment rates; however, it resulted in more drawbacks.

Accuracy of ultrasonography for renal stone detection and size determination: is it good enough for management decisions?

OBJECTIVES

To determine the sensitivity and specificity of ultrasonography (US) for detecting renal calculi and to assess the accuracy of US for determining the size of calculi and how this can affect counselling decisions.

MATERIALS AND METHODS

We retrospectively identified all patients at our institution with a diagnosis of nephrolithiasis who underwent US followed by non-contrast computed tomography (CT) within 60 days. Data on patient characteristics, stone size (maximum axial diameter) and stone location were collected. The sensitivity, specificity and size accuracy of US was determined using CT as the standard.

RESULTS

A total of 552 US and CT examinations met the inclusion criteria. Overall, the sensitivity and specificity of US was 54 and 91%, respectively. There was a significant association between sensitivity of US and stone size (P < 0.001), but not with stone location (P = 0.58). US significantly overestimated the size of stones in the 0-10 mm range (P < 0.001). Assuming patients with stones 0-4 mm in size will be selected for observation and those with stones ≥5 mm could be counselled on the alternative of intervention, we found that in 14% (54/384) of cases where CT would suggest observation, US would lead to a recommendation for intervention. By contrast, when CT results would suggest intervention as management, US would suggest observation in 39% (65/168) of cases. An average of 22% (119/552) of patients could be inappropriately counselled. Stones classified as 5-10 mm according to US had the highest probability (43% [41/96]) of having their management recommendation changed when CT was performed. The use of plain abdominal film of kidney, ureter and bladder and US increases sensitivity (78%), but 37% (13/35) of patients may still be counselled inappropriately to undergo observation.

CONCLUSIONS

Using US to guide clinical decision-making for residual or asymptomatic calculi is limited by low sensitivity and inability to size the stone accurately. As a result, one in five patients may be inappropriately counselled when using US alone.

Use of drug therapy in the management of symptomatic ureteric stones in hospitalised adults: a multicentre, placebo-controlled, randomised controlled trial and cost-effectiveness analysis of a calcium channel blocker (nifedipine) and an alpha-blocker (tamsulosin) (the SUSPEND trial)

BACKGROUND

Ureteric colic, the term used to describe the pain felt when a stone passes down the ureter from the kidney to the bladder, is a frequent reason for people to seek emergency health care. Treatment with the muscle-relaxant drugs tamsulosin hydrochloride (Petyme, TEVA UK Ltd) and nifedipine (Coracten(®), UCB Pharma Ltd) as medical expulsive therapy (MET) is increasingly being used to improve the likelihood of spontaneous stone passage and lessen the need for interventional procedures. However, there remains considerable uncertainty around the effectiveness of these drugs for routine use.

OBJECTIVES

To determine whether or not treatment with either tamsulosin 400 µg or nifedipine 30 mg for up to 4 weeks increases the rate of spontaneous stone passage for people with ureteric colic compared with placebo, and whether or not it is cost-effective for the UK NHS.

DESIGN

A pragmatic, randomised controlled trial comparing two active drugs, tamsulosin and nifedipine, against placebo. Participants, clinicians and trial staff were blinded to treatment allocation. A cost-utility analysis was performed using data gathered during trial participation.

SETTING

Urology departments in 24 UK NHS hospitals.

PARTICIPANTS

Adults aged between 18 and 65 years admitted as an emergency with a single ureteric stone measuring ≤ 10 mm, localised by computerised tomography, who were able to take trial medications and complete trial procedures.

INTERVENTIONS

Eligible participants were randomised 1 : 1 : 1 to take tamsulosin 400 µg, nifedipine 30 mg or placebo once daily for up to 4 weeks to make the following comparisons: tamsulosin or nifedipine (MET) versus placebo and tamsulosin versus nifedipine.

MAIN OUTCOME MEASURES

The primary effectiveness outcome was the proportion of participants who spontaneously passed their stone. This was defined as the lack of need for active intervention for ureteric stones at up to 4 weeks after randomisation. This was determined from 4- and 12-week case-report forms completed by research staff, and from the 4-week participant self-reported questionnaire. The primary economic outcome was the incremental cost per quality-adjusted life-year (QALY) gained over 12 weeks. We estimated costs from NHS sources and calculated QALYs from participant completion of the European Quality of Life-5 Dimensions health status questionnaire 3-level response (EQ-5D-3L™) at baseline, 4 weeks and 12 weeks.

RESULTS

Primary outcome analysis included 97% of the 1167 participants randomised (378/391 tamsulosin, 379/387 nifedipine and 379/399 placebo participants). The proportion of participants who spontaneously passed their stone did not differ between MET and placebo [odds ratio (OR) 1.04, 95% confidence interval (CI) 0.77 to 1.43; absolute difference 0.8%, 95% CI -4.1% to 5.7%] or between tamsulosin and nifedipine [OR 1.06, 95% CI 0.74 to 1.53; absolute difference 1%, 95% CI -4.6% to 6.6%]. There was no evidence of a difference in QALYs gained or in cost between the trial groups, which means that the use of MET would be very unlikely to be considered cost-effective. These findings were unchanged by extensive sensitivity analyses around predictors of stone passage, including sex, stone size and stone location.

CONCLUSIONS

Tamsulosin and nifedipine did not increase the likelihood of stone passage over 4 weeks for people with ureteric colic, and use of these drugs is very unlikely to be cost-effective for the NHS. Further work is required to investigate the phenomenon of large, high-quality trials showing smaller effect size than meta-analysis of several small, lower-quality studies.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN69423238. European Clinical Trials Database (EudraCT) number 2010-019469-26.

FUNDING

This project was funded by the National Institute for Health Research Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 19, No. 63. See the NIHR Journals Library website for further project information.

Economic impact of urinary stones

Kidney stones have been rising in prevalence in the United States and worldwide, and represent a significant cost burden. Cost effectiveness research in this area may enable improvements in treatment efficiency that can benefit patients, providers and the healthcare system. There has been limited research in the cost effectiveness of surgical interventions for stone disease, despite the diverse treatment approaches that are available. Medical expulsive therapy (MET) has been shown to improve rates of stone passage for ureteral stones, and there is evidence that this practice should be liberalized from the standpoint of both clinical and cost effectiveness. While conservative treatment following a primary stone event appears to be cost effective, the economic impact of medical therapy for recurrent stone formers requires clarification despite its clinical efficacy. Future study regarding the cost effectiveness of prevention and interventions for stone disease are likely to improve both the quality and efficiency of care.

Assessing the Magnitude of Effect of Bone Structures on Shockwave Lithotripsy Fragmentation: Results from an In Vitro Study

INTRODUCTION

Several anatomic and clinical factors have been implicated in the failure rates of shock wave lithotripsy (SWL), including the attenuating effects of bony structures. We designed an in vitro model that incorporates the lumbar spine, including vertebral bodies and transverse processes along the pathway of shockwaves, to mimic the clinical scenario during SWL of upper ureteral stones. We hypothesized that the presence of bone structures in the SWL pathway significantly affects the fragmentation rate.

MATERIALS AND METHODS

An ordnance gelatin (OG) model was conceptualized and created to allow a pig's lumbar spine to be embedded within it. Artificial urinary calculi weighing 2 ± 0.1 g (1.2-cm diameter) were prepared using BegoStone plaster. The trial was divided into two arms: group 1 models had OG only and served as the control and group 2 models had the bone embedded in the gelatin with stone wells placed above the transverse processes. Twenty-four stones per group were subjected to SWL using the STORZ MODULITH SLX-F2 lithotripter, using the same treatment parameters. Fragments were sieved through 2- and 4-mm filters, and the fragmentation coefficients (FC) were calculated. The Mann-Whitney test was used to compare FC between the two groups.

RESULTS

The mean fragmentation rate of group 1 was statistically significantly higher compared with group 2 using a 4-mm sieve (43% vs 0.62%, p < 0.001) and the 2-mm filter (18% vs 0.52%, p < 0.001).

CONCLUSIONS

The presence of bone structures dramatically reduces the fragmentation rate of phantom stones using an OG in vitro model. The OG model is inexpensive and simple to use to simulate clinical situations during SWL.

Cost Analysis of Flexible Ureteroscope Repairs: Evaluation of 655 Procedures in a Community-Based Practice

INTRODUCTION

The frequency of flexible ureteroscopy has increased with the introduction of improved instrumentation. Ureteroscopes allow increased endoscopic access to the ureter and kidney. However, maintenance and repair of scopes may increase the total procedure expense.

METHODS

In 3 years (8/2011-7/2014), 655 flexible ureteroscopies were performed at a single-specialty, urology, ambulatory surgery center. Procedures were performed by 26 board-certified urologists using four Olympus URF P5 flexible ureteroscopes. The instruments were handled by a single team and sterilized through the STERIS System E1. Repairs were performed by the manufacturer on an as needed basis. Patient records were reviewed to determine the preoperative diagnosis, operative time, location and size of the stone, and use of laser or ureteral sheath. The occurrence, nature of flexible ureteroscope damage, and cost of repairs were evaluated.

RESULTS

Of the ureteroscopies performed, 78% was for the treatment of calculi (50.1% in the kidney). Mean stone size was 8.5 ± 0.2 mm, with larger stones (11 mm) located in the kidney. The flexible ureteroscope was advanced over a guidewire (88% of cases); a laser fiber was introduced in 70%, and a ureteral sheath was used in 13.4%. Mean procedure time was 40 minutes. The most common reasons for ureteroscope repair were cloudy lens (16 repairs) and broken optic fibers (9 repairs). There were 31 repairs during the study period (average 21 cases per repair). Flexible ureteroscopes were out of service for an average of 11 days per repair (range 3-20). The total cost of repairs was $233,150 or ∼$7521 per repair. The average repair cost per flexible ureteroscopy performed was $355.

CONCLUSIONS

Expenses associated with instrument repair can significantly impact a procedure's net revenue, thus efforts should be made to minimize instrument breakage. The expense of repairing a flexible ureteroscope per procedure can be significant and needs to be considered when pricing this procedure.

Comparative effectiveness and safety of various treatment procedures for lower pole renal calculi: a systematic review and network meta-analysis

OBJECTIVE

To compare the effectiveness of various treatments used for lower pole renal calculi.

METHODS

We searched PubMed, EMBASE, CINAHL, the Cochrane Collaboration's Database of Systematic Reviews, the Cochrane Collaboration Central Register of Controlled Clinical Trials as well as ClinicalTrials.gov for reports up to 1 April 2014. The search was supplemented with abstract reports from various urology conferences. All randomised, 'blinded' clinical studies including patients treated for lower pole renal calculi of <20 mm were included for review. Two authors independently reviewed 5 194 articles, and identified and selected 13 trials for analysis. Network meta-analysis was performed to generate comparative statistics, while quality was assessed with the Jadad composite scale and risk of bias.

RESULTS

All treatment methods examined: percutaneous nephrolithotomy (PNL), ureterorenoscopy (URS) and extracorporeal shockwave lithotripsy (SWL) with an adjuvant therapy (such as inversion, hydration and forced diuresis) were more effective than SWL therapy alone, with risk ratios (95% confidence intervals) of being stone free of: PNL 2.19 (1.62-2.96); URS 1.23 (1.03-1.48); and SWL with an adjuvant therapy 1.30 (1.03-1.63). However, patients treated with the other treatment methods also had a higher risk of adverse events (AEs) compared with SWL, but there was no evidence of a convincing difference between the various techniques and AEs.

CONCLUSION

In stones of <10 mm, SWL with an adjuvant therapy appears to have better stone clearance, lower risk of AEs, and need for further treatment. PNL was most effective treating larger stones, after considering both effectiveness and safety of treatment. These should be considered by both physicians and patients alike when considering the choice of treatment and in the revision of clinical practice guidelines.

Fragmentation of urinary calculi in vitro by burst wave lithotripsy

PURPOSE

We developed a new method of lithotripsy that uses short, broadly focused bursts of ultrasound rather than shock waves to fragment stones. We investigated the characteristics of stone comminution by burst wave lithotripsy in vitro.

MATERIALS AND METHODS

Artificial and natural stones (mean ± SD size 8.2 ± 3.0 mm, range 5 to 15) were treated with ultrasound bursts using a focused transducer in a water bath. Stones were exposed to bursts with focal pressure amplitude of 6.5 MPa or less at a 200 Hz burst repetition rate until completely fragmented. Ultrasound frequencies of 170, 285 and 800 kHz were applied using 3 transducers, respectively. Time to fragmentation for each stone type was recorded and fragment size distribution was measured by sieving.

RESULTS

Stones exposed to ultrasound bursts were fragmented at focal pressure amplitudes of 2.8 MPa or greater at 170 kHz. Fractures appeared along the stone surface, resulting in fragments that separated at the surface nearest to the transducer until the stone was disintegrated. All natural and artificial stones were fragmented at the highest focal pressure of 6.5 MPa with a mean treatment duration of 36 seconds for uric acid stones to 14.7 minutes for cystine stones. At a frequency of 170 kHz the largest artificial stone fragments were less than 4 mm. Exposure at 285 and 800 kHz produced only fragments less than 2 mm and less than 1 mm, respectively.

CONCLUSIONS

Stone comminution with burst wave lithotripsy is feasible as a potential noninvasive treatment method for nephrolithiasis. Adjusting the fundamental ultrasound frequency allows for stone fragment size to be controlled.

A prospective, multi-institutional study of flexible ureteroscopy for proximal ureteral stones smaller than 2 cm

PURPOSE

Flexible ureteroscopy is rapidly becoming a first line therapy for many patients with renal and ureteral stones. However, current understanding of treatment outcomes in patients with isolated proximal ureteral stones is limited. Therefore, we performed a prospective, multi-institutional study of ureteroscopic management of proximal ureteral stones smaller than 2 cm to better define clinical outcomes associated with this approach.

MATERIALS AND METHODS

Adult patients with proximal ureteral calculi smaller than 2 cm were prospectively identified. Patients with concomitant ipsilateral renal calculi or prior ureteral stenting were excluded from study. Flexible ureteroscopy, holmium laser lithotripsy and ureteral stent placement was performed. Ureteral access sheath use, laser settings and other details of perioperative and postoperative management were based on individual surgeon preference. Stone clearance was determined by the results of renal ultrasound and plain x-ray of the kidneys, ureters and bladder 4 to 6 weeks postoperatively.

RESULTS

Of 71 patients 44 (62%) were male and 27 (38%) were female. Mean age was 48.2 years. ASA(®) score was 1 in 12 cases (16%), 2 in 41 (58%), 3 in 16 (23%) and 4 in 2 (3%). Mean body mass index was 31.8 kg/m(2), mean stone size was 7.4 mm (range 5 to 15) and mean operative time was 60.3 minutes (range 15 to 148). Intraoperative complications occurred in 2 patients (2.8%), including mild ureteral trauma. Postoperative complications developed in 6 patients (8.7%), including urinary tract infection in 3, urinary retention in 2 and flash pulmonary edema in 1. The stone-free rate was 95% and for stones smaller than 1 cm it was 100%.

CONCLUSIONS

Flexible ureteroscopy is associated with excellent clinical outcomes and acceptable morbidity when applied to patients with proximal ureteral stones smaller than 2 cm.

Tubeless percutaneous nephrolithotomy: outcomes with expanded indications

INTRODUCTION

Tubeless PCNL has been utilized to shorten hospital stay and improve patient postoperative pain control. Prior studies have excluded those patients with significant bleeding or other complications. Our objective was to evaluate the utility of tubeless PCNL in all patients irrespective of intraoperative outcome.

MATERIALS AND METHODS

A retrospective review of the charts of patients who underwent PCNL at our institute was performed. Patients were assigned to one endourologist Who routinely performed tubeless PCNL and to a second endourologist who routinely left a small-bore pigtail nephrostomy. Preoperative demographics operative and postoperative outcomes were compared.

RESULTS

Out of 159 patients included, 83 patients had tubeless PCNL while 76 patients had standard PCNL. There was no difference between groups regarding age, gender, ASA score, number, maximum diameter of stones, number of calyces involved, Stone density (HU), laterality and use of preoperative narcotics. While staghorn stones were more common in patients who underwent standard PCNL (p = 0.008). Tubeless patients had less number of access tracts (p ≤ 0.001), shorter hospital stay (1.7 vs. 3.0 days, p = 0.001) when compared to standard PCNL group. Multivariable analysis controlling for confounding factors including staghorn calculi and number of accesses confirmed that tubeless PCNL was associated with shorter hospital stay and less postoperative pain. There was no significant difference in complication rates between the two groups.

CONCLUSION

Our report confirms the previous reports of shorter hospital stay, less pain and analgesia as compared to standard PCNL, and establishes its safety irrespective of bleeding, perforation, extravasation or other intraoperative issues that have previously been utilized as exclusionary criteria for this approach.

The surgical management of kidney stone disease: a population based time series analysis

PURPOSE

We evaluate population based trends in the use of extracorporeal shock wave lithotripsy, ureteroscopy and percutaneous nephrolithotomy during the last 20 years, as well as assess the re-treatment rate and morbidity from treatment over time.

MATERIALS AND METHODS

Using administrative databases in the province of Ontario, Canada, a population based cross-sectional time series analysis was performed between July 1, 1991 and December 31, 2010. All extracorporeal shock wave lithotripsy, ureteroscopy and percutaneous nephrolithotomy procedures were identified, along with all hospital readmissions and emergency department visits within 7 days of treatment. The primary outcome was treatment use, and secondary outcomes were the need for ancillary treatment and hospital readmission or emergency department visit after treatment. Exponential smoothing and autoregressive integrated moving average (ARIMA) models were used to assess trends over time.

RESULTS

We identified 194,781 kidney stone treatments performed during the study period. Time series modeling revealed a significant increase in the use of ureteroscopy over time (25% to 59% of all procedures, p <0.0001) and a reciprocal decrease in the use of extracorporeal shock wave lithotripsy (69% to 34% of all procedures, p <0.0001). A corresponding significant decrease in the need for ancillary treatment over time (23% to 15%, p <0.0001) and increase in the need for hospital readmission (7% to 11%, p <0.0001) or emergency department visit (7% to 11%, p=0.0024) after treatment were also demonstrated.

CONCLUSIONS

Our population based study demonstrates a shift in the treatment paradigm with increased use of ureteroscopy over time and a reciprocal decrease in the use of extracorporeal shock wave lithotripsy. We also observed a corresponding decrease in ancillary treatment and increase in posttreatment morbidity over time.

Alpha-blockers as medical expulsive therapy for ureteral stones

BACKGROUND

Urinary stone disease is one of the most common reasons for patients visiting a urology practice, affecting about 5% to 10% of the population. Annual costs for stone disease have rapidly increased over the years and most patients with ureteral colic or other symptoms seek medical care. Stone size and location are important predictors of stone passage. In most cases medical expulsive therapy is an appropriate treatment modality and most studies have been performed with alpha-blockers. Alpha-blockers tend to decrease intra-ureteral pressure and increase fluid passage which might increase stone passage. Faster stone expulsion will decrease the rate of complications, the need for invasive interventions and eventually decrease healthcare costs. A study on the effect of alpha-blockers as medical expulsive therapy in ureteral stones is therefore warranted.

OBJECTIVES

This review aimed to answer the following question: does medical treatment with alpha-blockers compared to other pharmacotherapy or placebo impact on stone clearance rate, in adult patients presenting with symptoms of ureteral stones less than 10 mm confirmed by imaging? Other clinically relevant outcomes such as stone expulsion time, hospitalisation, pain scores, analgesic use and adverse effects have also been explored.

SEARCH METHODS

We searched the Cochrane Renal Group's Specialised Register to 9 July 2012 through contact with the Trials Search Co-ordinator using search terms relevant to this review. Studies contained in the Specialised Register are identified through search strategies specifically designed for CENTRAL, MEDLINE and EMBASE, handsearching conference proceedings, and searching the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

Randomised controlled trials (RCTs), comparing alpha-blockers with other pharmacotherapy or placebo on ureteral stone passage in adult patients were included.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. Summary estimates of effect were obtained using a random-effects model, and results were expressed as risk ratios (RR) and their 95% confidence intervals (CI) for dichotomous outcomes, and mean difference (MD) and 95% CI for continuous outcomes. Reporting bias was investigated using funnel plots. Subgroup analysis was used to explore possible sources of heterogeneity. Sensitivity analysis was performed removing studies of poor methodological quality.

MAIN RESULTS

Thirty-two studies (5864 participants) were included. The stone-free rates were significantly higher in the alpha-blocker group (RR 1.48, 95% CI 1.33 to 1.64) when compared to standard therapy. Stone expulsion time was 2.91 days shorter with the use of alpha-blockers (MD -2.91, 95% CI -4.00 to -1.81). Use of alpha-blockers reduced the number of pain episodes (MD -0.48, 95% CI -0.94 to -0.01), the need for analgesic medication (diclofenac) (MD -38.17 mg, 95% CI -74.93 to -1.41) and hospitalisation (RR 0.35, 95% CI 0.13 to 0.97). Patients using alpha-blockers were more likely to experience adverse effects when compared to standard therapy (RR 2.74, 95% CI 1.38 to 5.45) or placebo (RR 2.73, 95% CI 1.50 to 4.96). Most adverse effects were mild of origin and did not lead to cessation of therapy, and several studies reported no adverse events in either the treatment or control group.In 7/32 studies patients and doctors were both blinded. In the other studies blinding was not described in the methods or no blinding had taken place. Two studies described incomplete data and only one study showed a relatively high number of patients who withdrew from the study. These factors limited the methodological strength of the evidence found.

AUTHORS' CONCLUSIONS

The use of alpha-blockers in patients with ureteral stones results in a higher stone-free rate and a shorter time to stone expulsion. Alpha-blockers should therefore be offered as part of medical expulsive therapy as one of the primary treatment modalities.

Contemporary volume-outcome relationships for percutaneous nephrolithotomy: results from the Nationwide Inpatient Sample

INTRODUCTION/OBJECTIVE

We sought to examine the contemporary relationship between case volume and outcome for percutaneous nephrolithotomy (PCNL) using a publically available administrative database.

METHODS

A weighted sample of 7785 patients was obtained from the 2010 Healthcare Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (NIS). ICD-9-CM diagnostic codes were used to identify patients with urolithiasis (592.0, 592.1, and 592.9) who underwent percutaneous nephrostomy with fragmentation (5504). Charlson Comorbidity Indices (CCI) were calculated based on diagnostic codes for all patients. Hospital case volume was quartile classified and we then compared key outcomes (the complication rate, transfusion rate, length of stay [LOS], and in-hospital mortality rate) by volume quartile. We then performed multivariate analysis to examine the effect of CCI, annual volume, and age on key outcomes.

RESULTS

The overall complication rate was 17% in the weighted sample. In univariate analysis, statistically significant variation in the complication rate, CCI, transfusion rate, and in-hospital mortality was noted with regard to the hospital volume. The complication rate and transfusion rates varied by case volume, but in a nonlinear fashion, wherein rates were highest at the lowest and highest volume centers. CCI was strongly predictive (p<0.001) of complications and LOS in the multivariate analysis. Case volume was only predictive (p=0.042) of LOS in the multivariate analysis.

CONCLUSION

Annual case volume of the treating center was associated with shorter LOS after PCNL, but case volume was not independently predictive of complication or transfusion in multivariate analysis. CCI was a strong independent predictor of complication and LOS.

Management of 1-2 cm renal stones

INTRODUCTION

The preferred treatment of >1cm stone is shockwave lithotripsy (SWL), while that of stone <2 cm is percutaneous nephrolithotomy (PCNL), but treatment of 1-2 cm renal stones is a controversial issue. We searched the literature to present a comprehensive review on this group.

MATERIAL AND METHODS

Pubmed search of literature was done using the appropriate key words. We separately discussed the literature in lower polar and non lower polar stone groups.

RESULTS

For non lower polar renal stones of 1-2 cm, SWL is preferred approach, while for the lower polar stones; literature favors the use of PCNL. Retrograde intrarenal surgery (RIRS) is emerging as a promising technique for these calculi.

CONCLUSIONS

Treatment of renal stone disease depends on stone and patient related, as well as on renal anatomical factors. Treatment should be individualized according to site of stone and available expertise.

Laparoscopic management of pediatric renal and ureteric stones

OBJECTIVE

To assess the feasibility of laparoscopy in the treatment of pediatric urolithiasis, we report our experience with the transperitoneal laparoscopic removal of stones.

METHOD

Renal pelvic stones of size ≥1 cm on ultrasound were included for laparoscopic pyelolithotomy while smaller stones were managed with shock-wave lithotripsy monotherapy. Intrarenal stones, calyceal stones, complete staghorn stones, multiple stones and kidneys with intrarenal pelvis were excluded. Ureteric stones included for laparoscopic ureterolithotomy were of size ≥1 cm in the upper, mid or lower ureter, and smaller stones not responding to non-operative treatment.

RESULTS

A total of 22 procedures were performed: 12 pyelolithotomies, and 8 lower and 2 upper ureterolithotomies. Complete removal of calculi was accomplished in 21 (95.45%) procedures. Complications associated with laparoscopic lithotomy included urinoma (4.54%), failure (4.54%) and omental prolapse (4.54%).

CONCLUSION

Laparoscopic lithotomy is safe and feasible in pediatric urolithiasis with pyelic and ureteric stones, with minimal complications and failure rate.

Isolated upper pole access in percutaneous nephrolithotomy: a large-scale analysis from the CROES percutaneous nephrolithotomy global study

PURPOSE

We analyzed the indications for and outcomes of percutaneous nephrolithotomy using upper pole access.

MATERIALS AND METHODS

Between 2007 and 2009 prospective data were collected by the Clinical Research Office of the Endourological Society (CROES) from consecutive patients at 96 centers globally. Data on 4,494 patients were included in this analysis. Patients were divided into upper and lower pole access groups based on the location of percutaneous renal access. Preoperative characteristics and outcomes were compared between the 2 groups by univariate and multivariate tests.

RESULTS

The upper pole access group had more staghorn stones (21.7% vs 15.5%, p <0.001) and a greater stone burden (mean ± SD 476 ± 390.5 vs 442 ± 344.9 mm(2), p = 0.091). Mean operative time was 92.4 ± 46.1 and 75.1 ± 41.3 minutes in the upper and lower pole groups, respectively (p <0.001). The stone-free rate was lower in the upper pole access group (77.1% vs 81.6%, p = 0.030). The overall complication rate was higher in the upper pole group with a higher incidence of hydrothorax (5.8% vs 1.5%) but a lower incidence of pelvic perforation (1.8% vs 3.2%). Mean hospital stay was longer in the upper pole group (p = 0.048). Success and complication rates were similar in upper pole access subgroups, defined as definitive (staghorn and isolated upper calyceal stones) and elective (pelvic, middle calyceal and lower pole stones) indications.

CONCLUSIONS

Isolated upper pole access is indicated in a select group of patients with complex stones. Upper calyceal and staghorn stones are more commonly managed by upper pole access, which is associated with a higher complication rate and longer hospital stay as well as a lower stone-free rate due to procedure complexity.

Cost-effectiveness treatment strategies for stone disease for the practicing urologist

Kidney stone disease is rising in prevalence in the United States and abroad, and the cost burden of this condition is substantial. Although cost-effectiveness considerations are typically made by policymakers, individual practitioners have become increasingly involved in these discussions, to affect the rising costs of care and to assert control of treatment options. This article reviews existing literature regarding the cost-effectiveness of medical and surgical treatments for stone disease and identifies areas in which additional investigation is needed.

Treating renal calculi 1-2 cm in diameter with minipercutaneous or retrograde intrarenal surgery: a prospective comparative study

OBJECTIVE

To plan a prospective comparative case-control designed study aiming to compare minipercutaneous (miniperc) and retrograde intrarenal surgery (RIRS) for a renal calculus of size 1-2 cm.

PATIENTS AND METHODS

A total of 64 cases (32 in each arm) underwent miniperc and RIRS during the study period from March 2009 to April 2011. The primary and secondary outcome objective was stone-free rate and retreatment rate, complications, operation duration, patient visual pain scores, analgesic requirement, haemoglobin drop and hospital stay, respectively.

RESULTS

Miniperc and RIRS had stone clearance rates of 100% and 96.88%, respectively. In the RIRS group, one patient required retreatment at 1 month. Hospital stay (0.24) and intra-operative (0.99) and postoperative complications (0.60) were similar in both groups. Operation duration (P = 0.003) was lower in the miniperc group. Haemoglobin drop (P < 0.001), patient pain and visual analogue scale score (each P < 0.001) at 6, 24 and 48 h, as well as analgesic requirement (P < 0.003), were all lower in the RIRS group.

CONCLUSIONS

The stone clearances in both modalities are high and complications are low. RIRS requires a larger operation duration, although it is associated with favourable pain scores and a lower haemoglobin drop.

Factors influencing urologist treatment preference in surgical management of stone disease

OBJECTIVE

To assess the surgeon factors influencing the surgical treatment decisions for symptomatic stone disease. The factors influencing the selection of shock wave lithotripsy (SWL), ureteroscopy, or percutaneous nephrolithotomy to treat symptomatic stone disease are not well studied.

METHODS

Electronic surveys were sent to urologists with American Medical Association membership. Information on training, practice, and ideal treatment of common stone scenarios was obtained and statistically analyzed.

RESULTS

In November 2009, 600 surveys were sent and 180 were completed. High-volume SWL practices (>100 cases annually) were more common in community practice (P < .01), and high-volume ureteroscopy and percutaneous nephrolithotomy practices were more common in academic practice (P = .03). Community practice was associated with SWL selection for proximal urolithiasis and upper pole nephrolithiasis (P < .005). An increasing time since urologic training was associated with SWL selection for proximal urolithiasis and upper pole nephrolithiasis (P < .01). Urologists reporting shock wave lithotriptor ownership were 3-4 times more likely to select SWL for urolithiasis or nephrolithiasis compared with urologists who did not own a lithotripter (P < .01). Routine concern for stent pain and rigid ureteroscope preference (vs flexible) were associated with SWL selection (P < .03).

CONCLUSION

Surgeon factors significantly affected urolithiasis treatment selection. SWL was associated with community urology practice, increasing time since training, shock wave lithotriptor ownership, concern for stent pain, and ureteroscope preference.

Renal colic and urolithiasis practice patterns in Canada: a survey of Canadian Urological Association members

BACKGROUND

We describe the practice variability of CUA (Canadian Urological Association) members and factors which predict these patterns for common stone scenarios.

METHODS

We asked 308 English- and 52 French-speaking CUA members to complete online surveys in their respective languages. We collected demographic information on fellowship training, shock wave lithotripsy (SWL) access, academic setting and whether they are at a hospital with regionalized surgical services. Respondents indicated their actual as well as ideal treatment for scenarios of renal, proximal and distal ureteric calculi.

RESULTS

In total, 131 urologists responded (36% response rate), all of whom treated urolithiasis. Of this number, 17% had endourology fellowship training, 76% had access to SWL, 42% were at an academic institution and 66% were at institutions with regionalized surgical services. Actual and ideal treatment modalities selected for symptomatic, distal and proximal ureteric stones (4, 8, 14 mm) were consistent with published guidelines. There were discrepancies between the use of ureteroscopy and SWL in actual versus ideal scenarios. Actual and ideal practices were congruent for proximal ureteric stones and asymptomatic renal calculi. In multivariate analysis, respondents were less likely to perform ureteroscopy on proximal 4- and 8-mm stones if they were at a hospital with regionalized surgical services (OR: 0.097; 95% CI: 0.01-0.76, p = 0.03 and OR: 0.330; 95% CI: 0.13-0.83, p = 0.02).

INTERPRETATION

There is clinical variability in the management of urolithiasis in Canada; however, management approaches fall within published guidelines. Type of hospital and access to operating room resources may affect treatment modality selection.

Percutaneous nephrolithotomy for 1-2 cm lower-pole renal calculi

Objectives:

The most appropriate management of patients with lower-pole calyceal (LC) stones remains controversial. In this review we discuss the role of percutaneous nephrolithotomy (PCNL) in the management of LC stones 1–2 cm in maximum dimension.

Materials and Methods:

A detailed literature review was performed to summarize the recent technical developments and controversies in PCNL. The results of PCNL for 1-2 cm LC calculi were reviewed.

Results:

PCNL is increasingly employed as a primary modality in the treatment of LC calculi. It has a high success rate and acceptably low percentage of major complications in experienced hands. Supine position is found to be as safe and effective as prone position. Urologist-acquired access is associated with fewer access-related complications and better stone-free rates. Ultrasound is increasingly employed as an imaging modality for obtaining access. There have been increasing reports of tubeless PCNL in the literature. Most patients undergoing tubeless PCNL do not need hemostatic agents as an adjuvant for hemostasis. Non-contrast computed tomography does not yield statistically valuable increase in the diagnosis of significant residual stones compared with that of plain X-ray and linear tomography. Comprehensive metabolic evaluation and aggressive medical management can control new stone recurrences and growth of residual fragments following PCNL.

Conclusions:

PCNL is a highly effective procedure with consistently high stone-free rates when compared with extracorporeal shockwave lithotripsy or retrograde intrarenal surgery. The results also do not depend on anatomic factors and stone size. It is associated with low morbidity in experienced hands.