Casey A. Dauw

Contemporary Practice Patterns of Flexible Ureteroscopy for Treating Renal Stones: Results of a Worldwide Survey.

INTRODUCTION Flexible ureteroscopy (fURS) is increasingly used in the treatment of renal stones. However, wide variations exist in technique, use, and indications. To better inform our knowledge about the contemporary state of fURS for treating renal stones, we conducted a survey of endourologists worldwide. METHODS An anonymous online questionnaire assessing fURS treatment of renal stones, consisting of 36 items, was sent to members of the Endourology Society in October 2014. Responses were collected through the SurveyMonkey system over a 3-month period. RESULTS Questionnaires were answered by 414 surgeons from 44 countries (response rate 20.7%). U.S. surgeons accounted for 34.4% of all respondents. fURS was routinely performed in 80.0% of institutions, with 40.0% of surgeons performing >100 cases/year. Respondents considered fURS to be first-line therapy for patients with renal stones <2 cm and lower pole calculi. A substantial minority (11.3%) preferred fURS as a primary treatment modality for renal stones >2 cm. Basket displacement for lower pole stones was routinely performed by 55.8%. Ureteral access sheaths (UAS) were preferred for every case by 58.3%. Respondents frequently utilized high-power lasers and dusting techniques. Criteria for determining stone-free rate were defined as zero fragments or residual fragment (RF) <1, <2, <3, and <4 mm by 30.9%, 8.9%, 31.5%, 15.8%, and 11.2% of respondents, respectively. CONCLUSION The overwhelming majority of endourologists surveyed consider fURS as a first-line treatment modality for renal stones, especially those <2 cm. Use of UAS, high-power holmium lasers, and dusting technique has become popular among practitioners. When defining stone free after fURS, the majority of endourologists used a zero fragment or RF <2 mm definition.

Provider Variation in the Quality of Metabolic Stone Management

PURPOSE Urinary stone disease is a chronic condition for which secondary prevention (dietary and medical therapy guided by 24-hour urine collection results) has an important role. Assessing the response to these interventions with followup testing is recommended and yet to our knowledge provider compliance with these guidelines is unknown. MATERIALS AND METHODS Using Litholink® files from 1995 to 2013 we identified adults with urinary stone disease who underwent metabolic evaluation and the providers who ordered the evaluation. By focusing on patients with an abnormality on the initial collection we determined the proportion who underwent a followup test within 6 months of the initial test. Multilevel modeling was done to quantify variation in followup testing among providers after accounting for various patient and provider factors. RESULTS A total of 208,125 patients had an abnormality on the initial collection, of whom only 33,413 (16.1%) performed a repeat collection within 6 months. While most variation in followup testing was attributable to the patient, the provider contribution was nontrivial (18.0%). The specialty of the ordering provider was important. Patients who saw a urologist had 24% lower odds of repeat testing compared to those who saw a primary care physician (OR 0.76, 95% CI 0.67-0.86, p <0.001). CONCLUSIONS Followup testing is uncommon in patients with an abnormal initial 24-hour urine collection. Given the observed provider variation, efforts to educate providers on the value of followup testing are likely to have salutary effects on patients with metabolic stone disease.

Expulsive Therapy Versus Early Endoscopic Stone Removal in Patients with Acute Renal Colic: A Comparison of Indirect Costs

PURPOSE While medical expulsive therapy is associated with lower health care expenditures compared to early endoscopic stone removal in patients with renal colic, little is known about the effect of medical expulsive therapy on indirect costs. MATERIALS AND METHODS Using a previously validated claims based algorithm we identified a cohort of patients with acute renal colic. After determining the up-front treatment type (ie an initial course of medical expulsive therapy vs early endoscopic stone removal) we compared differences in rates of short-term disability filing. We used propensity score matching to account for differences between treatment groups such that patients treated with medical expulsive therapy vs early endoscopic stone removal were similar with regard to measured characteristics. RESULTS In total, 257 (35.8%) and 461 (64.2%) patients were treated with medical expulsive therapy or early endoscopic stone removal, respectively. There were no differences between treatment groups after propensity score matching. In the matched cohort the patients treated with medical expulsive therapy had a 6% predicted probability of filing a claim for short-term disability compared to 16.5% in the early endoscopic stone removal cohort (p <0.0001). Among the patients who filed for short-term disability those prescribed medical expulsive therapy had on average 1 fewer day of disability than those treated surgically (0.9 vs 1.8 days, p <0.001). CONCLUSIONS An initial trial of medical expulsive therapy is associated with significantly lower indirect costs to the patient compared to early endoscopic stone removal. These findings have implications for providers when counseling patients with acute renal colic.

Comparison of Perioperative Outcomes Between Holmium Laser Enucleation of the Prostate and Robot-Assisted Simple Prostatectomy

OBJECTIVES To compare perioperative outcomes for patients undergoing holmium laser enucleation of the prostate (HoLEP) and robotic-assisted simple prostatectomy (RSP) for benign prostatic hypertrophy (BPH). METHODS Patient demographics and perioperative outcomes were compared between 600 patients undergoing HoLEP and 32 patients undergoing RSP at two separate academic institutions between 2008 and 2015. RESULTS Patients undergoing HoLEP and RSP had comparable ages (71 vs 71, p = 0.96) and baseline American Urological Association Symptom Scores (20 vs 24, p = 0.21). There was no difference in mean specimen weight (96 g vs 110 g, p = 0.15). Mean operative time was reduced in the HoLEP cohort (103 minutes vs 274 minutes, p < 0.001). Patients undergoing HoLEP had lesser decreases in hemoglobin, decreased transfusions rates, shorter hospital stays, and decreased mean duration of catheterization. There was no difference in the rate of complications Clavien grade 3 or greater (p = 0.33). CONCLUSIONS HoLEP and RSP are both efficacious treatments for large gland BPH. In expert hands, HoLEP appears to have a favorable perioperative profile. Further studies are necessary to compare long-term efficacy, cost, and learning curve influences, especially as minimally invasive approaches become more widespread.

Randomized Controlled Trial Comparing Three Different Modalities of Lithotrites for Intracorporeal Lithotripsy in Percutaneous Nephrolithotomy

PURPOSE To compare the efficiency (stone fragmentation and removal time) and complications of three models of intracorporeal lithotripters in percutaneous nephrolithotomy (PCNL). MATERIALS AND METHODS Prospective, randomized controlled trial at nine centers in North America from 2009 to 2016. Patients were randomized to one of three lithotripter devices: the Cyberwand, a dual-probe ultrasonic device; the Swiss Lithoclast Select, a combination pneumatic and ultrasonic device; and the StoneBreaker, a portable pneumatic device powered by CO2 cartridges. Since the StoneBreaker lacks an ultrasonic component, it was used with the LUS-II ultrasonic lithotripter to allow fair comparison with combination devices. RESULTS Two hundred seventy patients were enrolled, 69 were excluded after randomization. Two hundred one patients completed the study: 71 in the Cyberwand group, 66 in the Lithoclast Select group, and 64 in the StoneBreaker group. The baseline patient characteristics of the three groups were similar. Mean stone surface area was smaller in the StoneBreaker group at 407.8 mm2 vs 577.5 mm2 (Lithoclast Select) and 627.9 mm2 (Cyberwand). The stone clearance rate was slowest in the StoneBreaker group at 24.0 mm2/min vs 28.9 mm2/min and 32.3 mm2/min in the Lithoclast Select and Cyberwand groups, respectively. After statistically adjusting for the smaller mean stone in the StoneBreaker group, there was no difference in the stone clearance rate among the three groups (p = 0.249). Secondary outcomes, including complications and stone-free rates, were similar between the groups. CONCLUSIONS The Cyberwand, Lithoclast Select, and the StoneBreaker lithotripters have similar adjusted stone clearance rates in PCNL for stones >2 cm. The safety and efficacy of these devices are comparable.

Factors Associated with Preventive Pharmacological Therapy Adherence among Patients with Kidney Stones

OBJECTIVE To determine adherence patterns for thiazide diuretics, alkali citrate therapy, and allopurinol, collectively referred to as preventive pharmacological therapy (PPT), among patients with kidney stones. METHODS Using medical claims data, we identified adults diagnosed with kidney stones between 2002 and 2006. Through National Drug Codes, we determined those with one or more prescription fills for a PPT agent. We measured adherence to PPT (as determined by the proportion of days covered formula) within the first 6 months of starting therapy and performed multivariate analysis to evaluate patient factors associated with PPT adherence. RESULTS Among 7980 adults with kidney stones who were prescribed PPT, less than one third (30.2%) were adherent to their regimen (indicated by proportion of days covered  ≥ 80%). Among those on monotherapy, rates of adherence differed by the type of PPT agent prescribed: 42.5% for thiazides, 40.0% for allopurinol, and 13.4% for citrate therapy. Factors that were independently associated with lower odds of PPT adherence included combination therapy receipt, female gender, less generous health insurance, and residence in the South or Northeast. In contrast, older patients and those with salaried employment had a higher probability of PPT adherence. CONCLUSION Adherence to PPT is low. These findings help providers identify patients where PPT adherence will be problematic. Moreover, they suggest possible targets for quality improvement efforts in the secondary prevention of kidney stones.

Geographic Variation in the Quality of Secondary Prevention for Nephrolithiasis.

OBJECTIVE To examine the variation in the quality of secondary prevention for nephrolithiasis across health care markets. METHODS Using analytical files from Litholink Corporation (2003-2012), we identified adults with nephrolithiasis and abnormal urine biochemistries on 24-hour urine collection. After assigning all patients to a hospital referral region (HRR), we determined the proportion of patients in each HRR who underwent on-treatment follow-up testing (our measure of quality). We then fitted multivariate hierarchical regression models to quantify the amount of variation in this proportion across HRRs. Finally, we examined for associations between a patients odds of on-treatment follow-up testing and the supply of primary care and specialist physicians in an HRR. RESULTS The mean rate on-treatment follow-up testing was exceedingly low at only 11.9%. This rate has been stable over time. There was fourfold variation in this rate across HRRs from as little as 6.6% to as high as 23.4%. Those HRRs with higher on-treatment follow-up testing rates tended to have a wealthier and more educated population (P = .01). Receipt of on-treatment follow-up testing was not associated with the number of specialists per capita. CONCLUSION Wide geographic variation exists in the quality of secondary prevention for patients with nephrolithiasis. Given that current guidelines recommend on-treatment follow-up testing, efforts to increase its uptake are needed.

Integration and utilization of modern technologies in nephrolithiasis research

Nephrolithiasis, or stones, is one of the oldest urological diseases, with descriptions and treatment strategies dating back to ancient times. Despite the enormous number of patients affected by stones, a surprising lack of conceptual understanding of many aspects of this disease still exists. This lack of understanding includes mechanisms of stone formation and retention, the clinical relevance of different stone compositions and that of formation patterns and associated pathological features to the overall course of the condition. Fortunately, a number of new tools are available to assist in answering such questions. New renal endoscopes enable kidney visualization in much higher definition than was previously possible, while micro-CT imaging is the optimal technique for assessment of stone microstructure and mineral composition in a nondestructive fashion. Together, these tools have the potential to provide novel insights into the aetiology of stone formation that might unlock new prevention and treatment strategies, and enable more effective management of patients with nephrolithiasis.

Intraoperative Management of an Incidentally Identified Ectopic Ureter Inserting Into the Prostate of a Patient Undergoing Radical Prostatectomy for Prostate Cancer: A Case Report

AbstractCongenital variations in urinary tract anatomy present unique surgical challenges when they present without prior knowledge. Ectopic ureters occur as a rare anatomic variation of the urinary tract and are often associated with duplicated renal collecting systems. While the condition is uncommon, even more atypical is its discovery and subsequent diagnosis during surgical intervention for treatment of localized prostate cancer.We describe the intraoperative management of a unique case of bilateral ectopic ureters, with a right-sided ureter inserting into the prostate of a 54-year-old male undergoing robotic-assisted radical prostatectomy. While unknown at the time of surgery, this right-sided ureter was associated with a nonfunctioning right upper renal moiety of a duplex renal collecting system. This aberration was discovered intraoperatively and confirmed with imaging, and a robotic-assisted radical prostatectomy with right distal ureterectomy was performed.

Follow-Up Care after ED Visits for Kidney Stones—A Missed Opportunity

Introduction: Followup care after an emergency department visit for kidney stones may help reduce emergency department revisits and increase use of stone prevention strategies. To test these hypotheses we analyzed medical claims from working age adults with kidney stones. Methods: Using data from MarketScan® (2003 to 2006) we identified patients with an emergency department visit for kidney stones. We then determined which patients had an outpatient visit within 90 days of emergency department discharge. Finally, we used multivariable logistic regression to evaluate the association between receipt of followup care and emergency department revisit as well as use of stone prevention strategies (24-hour urine testing and preventive pharmacological therapy prescription). Results: Only 48.0% (33,741) of patients seen in the emergency department for kidney stones received followup care, of which 68.3% was with a urologist. While followup care was not associated with fewer emergency department revisits, patients who received it were more likely to undergo 24-hour urine testing (predicted probability 2.2% vs 0.9%, p <0.001) and be prescribed preventive pharmacological therapy (predicted probability 10.6% vs 8.9%, p <0.001) compared to those who did not receive care. Among patients who received followup care, use of stone prevention strategies was higher when the care was delivered by a urologist (predicted probability 13.7% vs 12.3%, p=0.001). Conclusions: More than half of patients seen acutely in the emergency department for kidney stones do not receive followup care. Given that followup care is associated with greater use of stone prevention strategies, efforts to enhance linkages across health care settings are needed to provide higher quality care for patients with urinary stone disease.