<p><strong>PURPOSE: </strong>Shockwave lithotripsy (SWL) and ureteroscopy (URS) are the most commonly performed surgeries for kidney and ureteral stones, but the comparative effectiveness of these interventions at the population level is unclear. The purpose of our study was to compare retreatment for SWL and URS.</p>

<p><strong>MATERIALS AND METHODS: </strong>A retrospective cohort study using all-payer claims data for all patients who underwent SWL or URS from 1997-2016 at 74 hospitals in South Carolina was performed. The primary outcome measure was subsequent SWL or URS within 6 months of initial surgery. Pseudorandomized trials of URS versus SWL were performed for each year, applying propensity scores to balance hospital and patient characteristics. Discrete time failure models were fit using propensity-score weighted logistic regression.</p>

<p><strong>RESULTS: </strong>Overall, 136,152 URS and SWL surgeries were performed on 95,227 unique patients with retreatment representing 9% of all surgeries. 74,251 index surgeries were SWL (59.9%) and 49,743 were URS (40.1%). SWL was associated with a 20% increased odds of retreatment (OR 1.20, 95% CI 1.13, 1.26). The probability of retreatment was 7.5% for URS and 10.4% for SWL. SWL had the greatest risk for retreatment at months 2 (OR 1.85, 95% CI 1.64, 2.10) and 3 (OR 1.76, 95% CI: 1.50, 2.06). Initial SWL patients were more likely to have SWL for retreatment (84.6%) than were patients who had initial URS to have URS (29.3%).</p>

<p><strong>CONCLUSIONS: </strong>Compared to URS, SWL was associated with increased odds of retreatment. These results have implications for shared decision-making and value-based surgical treatment of nephrolithiasis.</p>

<p>Numerous medications can predispose patients to stone formation. Some induce metabolic changes that alter urine chemistries, such as topiramate, which can cause a mixed renal tubular acidosis. Others or their breakdown products form stones composed of the drugs themselves, like those that are renally excreted and become supersaturated in the urine in a favorable environment. Like all stones, they can cause obstruction and infection.</p>

<p>Here we present a case of ampicillin stone formation in an 11-year-old girl during a pelvic reconstructive procedure, which required ureteral stenting to prevent obstruction from an institutional guideline's perioperative antimicrobial dosing. While there are many reports of amoxicillin and ampicillin crystalluria, there is only one account in the literature of an adult with resultant ureteral obstruction requiring intervention. Our case is the first report, to our knowledge, in a child, and highlights the potential for significant crystal formation and if unrecognized, complete urinary obstruction. Since ampicillin is a commonly administered perioperatively, awareness of ampicillin stone formation during surgery is important.</p>

<p><b>OBJECTIVE: </b>To inform the development of strategies to improve adherence to guidelines, we sought to identify characteristics of pediatric patients with nephrolithiasis associated with completing 24-hour urine analyses.</p><p><b>MATERIALS AND METHODS: </b>We performed a retrospective cohort study of patients with nephrolithiasis aged 3 to 18 years treated in a large pediatric healthcare system from May 2012 to May 2017. Multivariable Cox models were fit to estimate the association between patient characteristics and completion of a 24-hour urine analysis.</p><p><b>RESULTS: </b>Among 623 patients, 317 (50.9%) completed a 24-hour urine collection. Median age was 14.4 years (IQR 10.5, 16.3). In adjusted analyses, age at diagnosis (HR 1.03; 95% CI 1.01-1.07), renal colic on presentation (HR 1.72; 95% CI 1.15-2.58), and family history of nephrolithiasis (HR 1.50; 95% CI 1.17-1.93) were associated with an increased likelihood of completion of a 24-hour urine. Public/government assistance insurance (HR 0.68; 95% CI 0.48-0.96) was associated with decreased likelihood of completing a 24-hour urine.</p><p><b>CONCLUSIONS: </b>Patients who had prior painful experiences with stones (renal colic), and potential better understanding of nephrolithiasis (family history, older age on presentation) were more likely to complete a 24-hour urine. Those patients with public insurance/government assistance were less likely to complete a 24-hour urine. These results can be used to develop strategies to improve pediatric patients' adherence to completing 24-hour urine collections.</p>

<p>Once considered rare, pediatric nephrolithiasis has become a critical field of study in the last decade due to the rapid increase in incidence. Understanding the changing epidemiology and lifelong implications of pediatric stone disease is critically important to effectively manage the individual patient as well as identify risk factors for childhood onset that could be modified. Determining the role of diagnostic imaging in children is a unique challenge as limiting radiation and imaging stewardship should be priorities. Approaches to management have also changed, as technology continues to evolve and both medical and surgical options expand.</p>

<p>We report successful percutaneous nephrolithotomy (PCNL) in an 8-week-old, 4.12 kg infant with a combined stone burden of &gt; 2 cm in a solitary kidney. The patient was born with thoracolumbar myelomeningocele and had developed recurrent urinary tract infections. Her size precluded retrograde intrarenal surgery and shockwave lithotripsy would be unlikely to clear the stone burden. Stone analysis revealed hydroxyapatite and carbonate apatite stones, and metabolic work up revealed hypercalciuria for which chlorothiazide was started. To our knowledge, this is the youngest patient to undergo PCNL reported in the literature.</p>