Randall's plaques have been long thought to be precursors for kidney stone formation, but how their presence impacts future stone recurrence is not known. The aim of this study was to determine whether patients with endoscopically visible plaques were more likely to have subsequent stone events compared to those without. The presence of Randall's plaque in adult patients was prospectively assessed during endoscopic cases as part of the Registry for Stones of the Kidney and Ureter (ReSKU). In each case, the visible Randall's plaque burden was scored by the attending surgeon as "none," "minimal," or "many." Data regarding stone composition, 24-hour urine tests, and subsequent stone events on follow up were collected. Stone events were defined as patient-reported stone passage or any primary operation for kidney stones; second-look or staged operations were not counted as separate stone events. We identified 673 subjects with a Randall's plaque assessment, of which 78 had "none," 306 had "minimal," and 289 had "many." Despite having no significant differences in initial stone burden, subjects with visible Randall's plaque ("minimal" or "many") had a higher relative risk of stone recurrences after surgery compared to those without (RRR 1.711 (1.121-2.611), p = 0.01). Interestingly, no significant differences in 24-hour urine analytes were observed. Subjects with visible plaque were more likely to have calcium-based stones (84% vs. 58%, p < 0.001). The presence of endoscopically visible Randall's plaque is associated with an increased risk of stone recurrence independent of urine composition.

You have accessJournal of UrologyStone Disease: Medical & Dietary Therapy (MP26)1 May 2024MP26-14 IS HYPEROXALURIA IN PATIENTS WITH URINARY STONE DISEASE ASSOCIATED WITH WORSENING RENAL FUNCTION? Maria C. Velasquez Escobar, Wilson Sui, Pablo Suarez, Heiko Yang, Justin S. Ahn, David Bayne, Tom Chi, and Marshall L. Stoller Maria C. Velasquez EscobarMaria C. Velasquez Escobar , Wilson SuiWilson Sui , Pablo SuarezPablo Suarez , Heiko YangHeiko Yang , Justin S. AhnJustin S. Ahn , David BayneDavid Bayne , Tom ChiTom Chi , and Marshall L. StollerMarshall L. Stoller View All Author Informationhttps://doi.org/10.1097/01.JU.0001009408.66023.77.14AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: It is well known that hyperoxaluria is associated with urinary supersaturation of calcium oxalate and crystal formation, causing urolithiasis and biomineralization. Recent studies have suggested an association between idiopathic and enteric hyperoxaluria with worsening renal functioning over time; a subset of patients will present with acute or chronic renal failure that may progress to end-stage renal disease. The goal of this study was to assess if persistent hyperoxaluria associated with urinary stone disease has been a neglected cause of chronic kidney disease. METHODS: The Registry for Stones of the Kidney and Ureter (ReSKU) was queried for all patients who underwent 24-hour urine studies from 2016 to 2023 and had an initial urinary oxalate ≥40mg/day. Demographic, disease specific and stone recurrence data were abstracted from the medical record. Patients were categorized into resolved hyperoxaluria if their last urinary oxalate was <40mg/day. The closest serum creatinine measurement to the initial 24-hour urine was abstracted in addition to the last one in the patient's medical record. The estimated glomerular filtration rate (eGFR) was calculated at each timepoint using the chronic kidney disease epidemiology collaboration (CKD-EPI) equation. RESULTS: 333 patients met our inclusion criteria with a mean initial oxalate of 56±31 mg/day. The median follow up was 6 months (IQR 1-23 months). The mean difference in serum creatinine was 0.03±0.23 mg/dL. 155 (47%) patients underwent multiple 24-hour urines; of these patients, 52%, had persistently elevated urinary oxalate (<40mg/day) on their last available 24-hour urine. Only 10% of our cohort had enteric hyperoxaluria. There was no difference between age, gender, race or etiology of hyperoxaluria between those patients with corrected and those with persistently elevated urinary oxalate. There were no differences in advancing chronic kidney disease (stage 1 to 2) between those with normalized and persistent hyperoxaluria (5.6% vs 13.1%, p=0.136). CONCLUSIONS: There is no difference in progression to chronic kidney disease in patients with idiopathic and enteric hyperoxaluria who exhibit persistently elevated oxalate levels compared to those with normalized levels. Source of Funding: N/A © 2024 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 211Issue 5SMay 2024Page: e419 Advertisement Copyright & Permissions© 2024 by American Urological Association Education and Research, Inc.Metrics Author Information Maria C. Velasquez Escobar More articles by this author Wilson Sui More articles by this author Pablo Suarez More articles by this author Heiko Yang More articles by this author Justin S. Ahn More articles by this author David Bayne More articles by this author Tom Chi More articles by this author Marshall L. Stoller More articles by this author Expand All Advertisement PDF downloadLoading ...

You have accessJournal of UrologyCME1 Apr 2023MP10-08 PHENOTYPING PATIENTS WITH NEPHROLITHIASIS: CAN WE PREDICT ABNORMAL 24-HOUR URINE PARAMETERS BASED ON INITIAL STONE PRESENTATION? Kevin Chang, Wilson Sui, Heiko Yang, Kevin Shee, Rei Unno, Ukrit Rompsaithong, Marshall Stoller, and Tom Chi Kevin ChangKevin Chang More articles by this author , Wilson SuiWilson Sui More articles by this author , Heiko YangHeiko Yang More articles by this author , Kevin SheeKevin Shee More articles by this author , Rei UnnoRei Unno More articles by this author , Ukrit RompsaithongUkrit Rompsaithong More articles by this author , Marshall StollerMarshall Stoller More articles by this author , and Tom ChiTom Chi More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003225.08AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The American Urologic Association defines high risk stone formers as those with medical conditions predisposing to stone formation, solitary kidneys, repeated stone episodes or those who present with multiple stones initially. How the initial radiographic stone configuration is related to 24-hour urine test outcomes is unknown. We hypothesized that those with small, unilateral stones may have different 24-hour urine parameters than those with bilateral or larger stone burdens. METHODS: The Registry for Stones of the Kidney and Ureter (ReSKU) database was queried for all patients who underwent 24-hour urine testing between 2015 and 2022. In addition to demographic characteristics and medical history, the initial presenting stone characteristics were identified and characterized according to laterality, stone count, overall stone burden and location. These patients were then categorized by presenting phenotype, and their 24-hour urine characteristics were compared using ANOVA for continuous variables and chi-square for categorical variables. RESULTS: 511 patients met our inclusion criteria and were categorized into one of six phenotypes - based on laterality, stone size and number of stones (Figure 1). The mean age for the entire cohort was 55 years, 51% male and for 90% of patients this was their first stone. In comparing the 24-hour urinary analytes as continuous variables across all six phenotypes, there were no differences. Rates of abnormal urinary analytes were tabulated (Figure 1) and no significant differences in rates of hypovolemia (≤2L, p = 0.725), hypercalciuria (>250mmol/day for males, >200mmol/day for females, p = 0.372), hyperoxaluria (>40mg/day, p = 0.746) or hypocitraturia (<450mmol/day for males, <550mmol/day for females, p = 0.422) or hyperuricosuria (>0.8 mmol/day for males, >0.750mmol/day for females, p = 0.659) were noted. CONCLUSIONS: There was no difference when comparing values of 24-hour urine analytes based on initial stone configuration, including stone multiplicity and/or volume, which calls into question the utility of recommending 24-hour testing for high volume stone formers. Further research should focus on novel methods to identify patients at high risk for stone recurrence or metabolic abnormalities. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e117 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Kevin Chang More articles by this author Wilson Sui More articles by this author Heiko Yang More articles by this author Kevin Shee More articles by this author Rei Unno More articles by this author Ukrit Rompsaithong More articles by this author Marshall Stoller More articles by this author Tom Chi More articles by this author Expand All Advertisement PDF downloadLoading ...

You have accessJournal of UrologyCME1 Apr 2023MP05-02 TISSUE-RESIDENT MACROPHAGES ARE ASSOCIATED WITH RANDALL'S PLAQUES Heiko Yang, Hanbing Song, Tom Chi, Marshall Stoller, Sunita Ho, and Franklin W. Huang Heiko YangHeiko Yang More articles by this author , Hanbing SongHanbing Song More articles by this author , Tom ChiTom Chi More articles by this author , Marshall StollerMarshall Stoller More articles by this author , Sunita HoSunita Ho More articles by this author , and Franklin W. HuangFranklin W. Huang More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003216.02AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The cellular and molecular mechanisms involved in Randall’s plaque formation are poorly understood. Macrophages are closely associated with Randall’s plaques and are hypothesized to be an effector cell type, but their role in biomineralization remains unclear. The objective of this study was to better understand the origin and nature of Randall’s plaque-associated macrophages using single nucleus RNA sequencing (snRNAseq). METHODS: Randall’s plaque and renal papillary tissues were collected from adult patients undergoing stone surgery. Randall’s plaque tissue was obtained from endoscopic biopsies while whole renal papilla tissue were obtained from fresh nephrectomy specimens. snRNAseq was performed using the 10X Genomics platform. Additional tissue was used for immunohistologic staining. Analysis was conducted using R Studio and Seurat. Intercellular molecular interactions were predicted using CellphoneDB. RESULTS: A total of 34,468 nuclei from 24 patients (9 targeted Randall’s plaque biopsies) were included in the final analytic dataset. Myeloid cells were annotated using commonly expressed markers. We identified a macrophage population enriched in Randall’s plaque tissue consistent with previously described tissue-resident macrophages. Chemokine signaling was predicted to originate from epithelial cells in the loop of Henle rather than vascular endothelial cells. In addition to expressing both M1 and M2 polarization markers, which was confirmed with immunofluorescent staining (Figure 1), these macrophages expressed multiple isoforms of collagen and had ligand-receptor interactions with fibroblasts in fibrosis-promoting pathways. CONCLUSIONS: Tissue-resident macrophages, rather than monocyte-derived macrophages, are associated with Randall’s plaques and may contribute to collagen deposition and fibrosis. Further investigation is required to determine whether these cells play a causative role in Randall’s plaque formation. Source of Funding: California Urology Foundation (HY), UCSF Department of Medicine (FWH) © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e43 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Heiko Yang More articles by this author Hanbing Song More articles by this author Tom Chi More articles by this author Marshall Stoller More articles by this author Sunita Ho More articles by this author Franklin W. Huang More articles by this author Expand All Advertisement PDF downloadLoading ...

You have accessJournal of UrologyCME1 Apr 2023MP21-13 LOWER SOCIOECONOMIC STATUS IS ASSOCIATED WITH HIGHER URINARY SODIUM: IMPLICATIONS FOR DIETARY STONE GUIDANCE IN UNDERSERVED COMMUNITIES Wilson Sui, Kevin Chang, Heiko Yang, Kevin Shee, Reuben Sarwal, Rei Unno, Ukrit Rompsaithong, David Bayne, Marshall Stoller, and Tom Chi Wilson SuiWilson Sui More articles by this author , Kevin ChangKevin Chang More articles by this author , Heiko YangHeiko Yang More articles by this author , Kevin SheeKevin Shee More articles by this author , Reuben SarwalReuben Sarwal More articles by this author , Rei UnnoRei Unno More articles by this author , Ukrit RompsaithongUkrit Rompsaithong More articles by this author , David BayneDavid Bayne More articles by this author , Marshall StollerMarshall Stoller More articles by this author , and Tom ChiTom Chi More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003246.13AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Lower socioeconomic status (SES) is associated with higher stone burden at presentation, requiring more frequent and invasive procedures. Unhealthy dietary patterns and impaired access to healthy food in low-income communities are thought to exacerbate this problem. To investigate whether the relationship between SES, diet and stone disease is reflected in 24-hour urine composition, we investigated the associations between 24-hour urine parameters and median income by home zip code in stone patients. METHODS: The Registry for Stones of the Kidney and Ureter was queried for all adult subjects who underwent a 24-hour urine test between 2015 and 2022. A similar number of subjects who were prospectively followed but did not complete 24-hour urine testing were also evaluated. Demographic data including home zip code and clinical characteristics were abstracted for analysis. We then used publicly available zip-code level data from the U.S. Census Bureau to stratify patients into quintiles by median income and 24-hour urine parameters were compared. A multivariable linear regression model was created to identify significant independent predictors among demographic and past medical history characteristics. RESULTS: Of 1,224 subjects who met inclusion criteria, 635 (52%) had undergone 24-hour urine testing. Compared to those in the top quintile, individuals in the bottom quintile of income were younger, more likely to be non-white and had a higher proportion of diabetes (16% vs 9%, p = 0.014), chronic kidney disease (6.2% vs 2.4%, p = 0.038) and chronic obstructive pulmonary disease (5% vs 1.6%, p=0.036). These patients were also less likely to have 24-hour urine testing (42% versus 52%, p=0.004). On comparison of 24-hour urine data, individuals in the bottom quintile of income had higher mean urinary sodium and on multivariable linear regression controlling for demographic and clinical characteristics, lower income remained significantly associated with increased urinary sodium (β = 5.2 ± 2.3, p=0.025). CONCLUSIONS: Lower SES is associated with higher levels of urinary sodium. In addition to reinforcing the need for more epidemiologic investigation and public health intervention, this finding highlights SES as a consideration for tailoring dietary modifications. Source of Funding: none © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e291 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Wilson Sui More articles by this author Kevin Chang More articles by this author Heiko Yang More articles by this author Kevin Shee More articles by this author Reuben Sarwal More articles by this author Rei Unno More articles by this author Ukrit Rompsaithong More articles by this author David Bayne More articles by this author Marshall Stoller More articles by this author Tom Chi More articles by this author Expand All Advertisement PDF downloadLoading ...

You have accessJournal of UrologyCME1 May 2022PD50-08 PRACTICE PATTERNS IN THE SURGICAL MANAGEMENT OF UROLITHIASIS: DATA FROM THE AUA QUALITY (AQUA) REGISTRY Amy Showen, Justin Ahn, Raymond Fang, Cody Weiss, William Meeks, Matthew Cooperberg, David Bayne, and Tom Chi Amy ShowenAmy Showen More articles by this author , Justin AhnJustin Ahn More articles by this author , Raymond FangRaymond Fang More articles by this author , Cody WeissCody Weiss More articles by this author , William MeeksWilliam Meeks More articles by this author , Matthew CooperbergMatthew Cooperberg More articles by this author , David BayneDavid Bayne More articles by this author , and Tom ChiTom Chi More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000002621.08AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Surgical management of urolithiasis is common, yet little national level data exists regarding current practice patterns. This study aimed to determine (1) practice rates for ureteroscopy (URS), shockwave lithotripsy (SWL), and percutaneous nephrolithotomy (PCNL), (2) secondary procedure rates, and (3) the impact of patient, provider, and practice characteristics on surgical practice patterns utilizing a urology-specific national database. METHODS: The AUA Quality (AQUA) Registry extracts patient data from participating urology practices from local electronic health records. Current Procedural Terminology and International Statistical Classification of Diseases 9/10 codes between January 1, 2014 and December 31, 2020 were used to identify urolithiasis procedures. Provider and practice characteristics were collected from the AUA Census. Patient, provider, and practice characteristics associated with primary and secondary procedures were evaluated using generalized linear models. RESULTS: 137,477 individuals with stone disease were treated surgically by 1,805 providers at 186 practices across the United States. 78,334 (56.9%) underwent URS, 52,645 (38%) underwent SWL, 6,209 (4.5%) underwent PCNL, and 288 (0.002%) underwent other open or laparoscopic surgical procedures. Of the 137,477 individuals treated surgically, 40,968 (29.8%) patients had a secondary procedure performed within one year of initial surgery, including 19,000 (24.3%), 19,191 (36.5%), and 2682 (43.2%) of those who underwent URS, SWL, and PCNL as their primary procedure, respectively. Patient, provider, and practice markers for poorer access to medical care were associated with undergoing PCNL or open/laparoscopic stone surgery (Table 1). CONCLUSIONS: This national representation of practicing urologists demonstrates that while URS is the most common surgical stone procedure performed, more invasive surgery is associated with characteristics that may be a proxy for more complex stone disease or poorer access to medical care. AQUA data should be used by urologists to benchmark and improve practice patterns. Source of Funding: University of California, San Francisco Resident Research Grant © 2022 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 207Issue Supplement 5May 2022Page: e838 Advertisement Copyright & Permissions© 2022 by American Urological Association Education and Research, Inc.MetricsAuthor Information Amy Showen More articles by this author Justin Ahn More articles by this author Raymond Fang More articles by this author Cody Weiss More articles by this author William Meeks More articles by this author Matthew Cooperberg More articles by this author David Bayne More articles by this author Tom Chi More articles by this author Expand All Advertisement PDF downloadLoading ...

You have accessJournal of UrologyStone Disease: Basic Research & Pathophysiology (MP07)1 Sep 2021MP07-16 FATTY ACID BINDING PROTEIN 4 ATTENUATES MACROPHAGE AND TUBULAR CELLS CRYSTAL PHAGOCYTOSIS TO DRIVE RENAL CALCIUM OXALATE STONE DEVELOPMENT Kazumi Taguchi, Rei Unno, Teruaki Sugino, Kengo Kawase, Heiko Yang, Shuzo Hamamoto, Atsushi Okada, Marshall Stoller, Takahiro Yasui, and Tom Chi Kazumi TaguchiKazumi Taguchi , Rei UnnoRei Unno , Teruaki SuginoTeruaki Sugino , Kengo KawaseKengo Kawase , Heiko YangHeiko Yang , Shuzo HamamotoShuzo Hamamoto , Atsushi OkadaAtsushi Okada , Marshall StollerMarshall Stoller , Takahiro YasuiTakahiro Yasui , and Tom ChiTom Chi View All Author Informationhttps://doi.org/10.1097/JU.0000000000001980.16AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Urolithiasis is a significant source of morbidity, and its incidence has increased significantly over the last decades. This rise has been linked with concurrent increasing rates of obesity and hyperlipidemia. We previously reported that fatty acid binding protein (FABP) 4, a regulator of lipid metabolism, was associated with Randall's plaques formation utilizing a transcriptomics approach in patients with urolithiasis. In this study, we elucidate the role of FABP4 function in renal calcium oxalate stone development with a transgenic mouse and gene-manipulated cell line. METHODS: 1)We compared renal and urinary crystal development between the Fabp4 knockout (KO) and wildtype (WT) mice using a nephrocalcinosis model mouse administered glyoxylate for 6 days. We further performed an RNA-sequence to analyze the gene expression patterns and pathways between the WT and KO mice to investigate the role of Fabp4 on urolithiasis. 2)An in vitro study using murine renal tubular cells (RTC) was conducted to examine calcium oxalate crystallization via Fabp4. We compared the control group with the Fabp4 knockdown group after 6 hours exposure of calcium oxalate monohydrate (COM). RESULTS: 1)The Fabp4 KO mice had significantly larger amounts of renal crystal deposits and urinary crystal than the WT mice. Additionally, the gene expression level of Ccl2 was lower in the Fabp4 KO mice than in the WT mice (figure 1A). The RNA-sequence result demonstrated that there were 16 genes commonly differentiated (>2-fold) before and after renal crystal development in the Fabp4 KO mice compared with the WT mice. These genes were associated with downregulation of antioxidant activity, IgA binding, and Toll-like receptor binding; cell-cell adhesion and neutrophil aggregation; and IgA immunoglobulin complex in Gene Ontology analysis.2)In the Fabp4 knockdown RTC, COM crystal endocytosis rate was significantly lower than the control. Gene expression levels of Ccl2 and Tumor necrosis factor were higher in the Fabp4 knockdown RTC than those of the control (figure 1B). CONCLUSIONS: We have found that Fabp4 deficiency suppresses macrophage function and crystal endocytosis in renal tubular stones, leading to stone development. These data support a causal role for FABP4 in driving urinary stone formation. Source of Funding: None © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e145-e146 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Kazumi Taguchi More articles by this author Rei Unno More articles by this author Teruaki Sugino More articles by this author Kengo Kawase More articles by this author Heiko Yang More articles by this author Shuzo Hamamoto More articles by this author Atsushi Okada More articles by this author Marshall Stoller More articles by this author Takahiro Yasui More articles by this author Tom Chi More articles by this author Expand All Advertisement Loading ...

You have accessJournal of UrologyGeneral & Epidemiological Trends & Socioeconomics: Quality Improvement & Patient Safety IV (MP83)1 Apr 2020MP83-05 RESULTS FROM MULTI-INSTITUTIONAL IMPLEMENTATION OF A NEAR-MISS RESIDENT CONFERENCE Justin Ahn*, Bruce Dalkin, Hunter Wessells, Marshall Stoller, Tom Chi, and Mathew Sorensen Justin Ahn*Justin Ahn* More articles by this author , Bruce DalkinBruce Dalkin More articles by this author , Hunter WessellsHunter Wessells More articles by this author , Marshall StollerMarshall Stoller More articles by this author , Tom ChiTom Chi More articles by this author , and Mathew SorensenMathew Sorensen More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000975.05AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Clinical errors almost resulting in adverse patient events, also known as near misses, are common and can serve as warning signs of unsafe practices. They are routinely underreported and rarely openly discussed. Present day morbidity & mortality conferences (M&M) serve as the primary forum for discussing patient complications, but they are typically conducted in department-wide settings that may be intimidating for learners, require extensive preparation by the presenters, and focus on high acuity events. A novel resident-centered conference was introduced to focus on the discussion of near-miss clinical events. METHODS: A near-miss quality improvement (QI) conference was implemented at the urology residency programs of University of Washington and University of California San Francisco. The conference is held for one hour in a roundtable setting with residents only except for a chosen faculty moderator. Each resident is asked to present one personal near-miss case in 2 minutes, followed by 3 minutes for group discussion. No formal slides or presentations are required and cases discussed are separate from those discussed at M&M. Case summaries are transcribed and participants receive post session surveys. RESULTS: Thirty-three near-miss cases were recorded and categorized from both institutions over multiple sessions (Figure 1). The top 3 types of cases were: near wrong surgery or patient; surgical error/misjudgment; and communication problems with patients. Twenty resident survey responses were received with 95% of respondents in favor of continuing the conference on a recurring basis at a median interval of every 3 months. The most common words used to describe the conference were categorized as educational (40%), therapeutic (25%), and enjoyable (20%). CONCLUSIONS: A novel near-miss QI conference was well received by residents at 2 academic Urology training programs and shows great educational potential to help prevent adverse events across peers. Through our experience we confirmed that creating a supportive non-accusatory environment is critical to conference success. Future goals will focus on expanding this conference to other training programs and specialties, while also creating a centralized case database to collaborate and share lessons learned. Source of Funding: none © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e1257-e1257 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Justin Ahn* More articles by this author Bruce Dalkin More articles by this author Hunter Wessells More articles by this author Marshall Stoller More articles by this author Tom Chi More articles by this author Mathew Sorensen More articles by this author Expand All Advertisement PDF downloadLoading ...

INTRODUCTION AND OBJECTIVE: Prior studies have shown significant differences in glomerular filtration rate (GFR) between stone formers and non-stone formers. There is evidence that nephrolithiasis is a risk factor for chronic kidney disease (CKD). The role of kidney function in kidney stone formation however largely remains unexplored. The objective of this study is to investigate differences in kidney function decline between stone formers and non-stone formers over time. METHODS: A retrospective study was undertaken using de-identified patient data at our tertiary care center. Serum creatinine values of adults (age ≥ 18) were used to calculate GFR using the CKD-EPI creatinine equation. The primary outcome was change in GFR per year using an adjusted linear model. An adjusted cox-model was used to calculate the average risk of stone formation associated with GFR decline in stone formers based on date of initial nephrolithiasis diagnosis. Our secondary outcome was GFR change post stone formation stratified by surgical versus non-surgical intervention. RESULTS: Complete data for analysis was obtained from 3,450 stone formers and 112,072 non-stone formers after review of medical record data between 2010 and 2019. Stone formers had an overall GFR decline of 2.8 cc/min per year (p-value < 0.001) compared to a decline of 0.04 cc/min per year (p-value = 0.38) in non-stone forming patients. A fully adjusted cox-model indicated, on average, each 1 cc/min decline in GFR was associated with an increased risk of stone development in the following 2 years by 3.7%. Stone formers who underwent surgical intervention (PNL, URS, or SWL) had stable GFR post-operatively at 1 year. Patients who did not undergo surgical intervention had GFR decline of 0.82 cc/min CI [-1.56, -0.08] at 1 year (p-value = 0.03). CONCLUSIONS: A decline in GFR is associated with risk of kidney stone presentation up to 2 years prior to a stone event. This suggests that upstream changes in the renal papilla which affect GFR also may be contributing to mineralization. Kidney function decline could be used as a possible predictive tool for risk of stone formation. Additionally, surgical intervention is associated with preservation of GFR within one year after stone event. Clinically, unexplained GFR decline should increase suspicion for nephrolithiasis and appropriate evaluation and treatment should be considered.Source of Funding: none

You have accessJournal of UrologyStone Disease: Surgical Therapy V (PD34)1 Apr 2020PD34-12 RELATIONSHIP BETWEEN PREOPERATIVE URINE CULTURE AND COMPLICATION RATE IN A HIGH VOLUME STONE CENTER David Bayne*, Justin Ahn, Weiguo Hu, Bo Xiao, Boxing Su, Marshall Stoller, Tom Chi, and Jianxing Li David Bayne*David Bayne* More articles by this author , Justin AhnJustin Ahn More articles by this author , Weiguo HuWeiguo Hu More articles by this author , Bo XiaoBo Xiao More articles by this author , Boxing SuBoxing Su More articles by this author , Marshall StollerMarshall Stoller More articles by this author , Tom ChiTom Chi More articles by this author , and Jianxing LiJianxing Li More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000905.012AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: We have previously demonstrated that higher rates of struvite and infection stones exist in Chinese compared to North American nephrolithiasis patients. These high quality cross-cultural data create a unique opportunity to study the natural history of infectious stones. We hypothesized that positive urine culture prior to surgery for urolithiasis will predict for perioperative surgical complications, regardless of preoperative treatment status. Using an international stone registry we investigated the complication rate after surgery for kidney stones comparing patients with positive urine cultures and urine cultures with no growth prior to surgery. METHODS: Prospectively collected data from the Registry for Stones of the Kidney and Ureter (ReSKU) composed of patients from one high volume stone center in China and one in the United States between September 2015 to October 2019 were investigated to evaluate preoperative urine culture data and post operativecomplication rates. Included were all consecutive patients presented for treatment at a tertiary referral stone center. Excluded were patients missing data on preoperative urine culture or treatment status. Statistical analysis was performed in R version 3.5. RESULTS: For this prospective cohort study, a total of 1588 patient records were included. Of these records, complete culture and complication data were available for 241 patients. All positive urine cultures (n=109) were treated prior to surgery. In total there were a total of 11 complications (Clavien-Dindo 1-5) Univariate analysis revealed that having a positive urine culture prior to surgery was associated with a postoperative Clavien-Dindocomplication (p=0.025, OR 5.81). CONCLUSIONS: Despite treatment for preoperative positive urine cultures, a positive preoperative culture was still associated with the presence of post-operative infectious complications in stone surgery. Although rates are low overall, in high risk patients a post treatment test of cure prior to stone surgery and extended postoperative antibiotics may be prudent toincrease patient safety for stone surgery. Source of Funding: NIH2018P20DK © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e716-e716 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information David Bayne* More articles by this author Justin Ahn More articles by this author Weiguo Hu More articles by this author Bo Xiao More articles by this author Boxing Su More articles by this author Marshall Stoller More articles by this author Tom Chi More articles by this author Jianxing Li More articles by this author Expand All Advertisement PDF downloadLoading ...

INTRODUCTION AND OBJECTIVE: Supracostal renal access for endourologic intervention is frequently useful for obtaining access to the upper, mid, and rarely the lower kidney. Upper pole access in particular can afford optimal access to the collecting system and ureter due to renal orientation. However supracostal and upper pole punctures are classically associated with higher rates of pulmonary complications. The ribs can also interfere with imaging and instrumentation. Because of these limitations, there is a tendency towards lower pole punctures in the global urologic community. Ultrasound has become increasingly popular for percutaneous renal access and can potentially address the aforementioned limitations. We illustrate our technique for ultrasound guided supracostal renal access. METHODS: We compiled intraoperative video and ultrasound imaging from a prone percutaneous nephrolithotomy case to illustrate the specific steps and technical considerations for supracostal renal access using ultrasound exclusively. We chose a male patient with a partial staghorn stone who provided consent for filming and use of his patient data. RESULTS: The patient was brought to the operating room and underwent initial survey ultrasound of his right kidney to identify renal and adjacent anatomy, and to choose a puncture site. Through specific maneuvers and positioning of the probe, we were able to identify critical adjacent organs as well as an optimal percutaneous window into a mid renal calyx in the 10th intercostal space. Under ultrasound guidance, we percutaneously accessed this target calyx and dilated a tract using a Seldinger technique to facilitate placement of a 24-French renal access sheath. The patient’s lithotripsy and post-operative course were routine. CONCLUSIONS: A supracostal approach can provide optimal renal access, and its distinct challenges can be overcome with specific ultrasound technique. The ability to visualize anatomy and adjacent structures in real time is invaluable to reducing surgical risk and optimizing clinical outcomes. Appropriate training makes ultrasound guided access readily achievable by urologists, and overtime it can complement fluoroscopy if not replace it as one’s skill set advances. Source of Funding: none

You have accessJournal of UrologySurgical Technology & Simulation: Training & Skills Assessment II (MP35)1 Apr 2019MP35-06 ASSESSING THE UROLOGIC TRAINEE'S LEARNING CURVE FOR ULTRASOUND GUIDED RENAL PUNCTURES DURING PERCUTANEOUS NEPHROLITHOTOMY Manuel Armas-Phan*, David Tzou, David Bayne, Scott Wiener, Adam Gadzinski, Ian Metzler, Kelly Walker, Marshall Stoller, and Tom Chi Manuel Armas-Phan*Manuel Armas-Phan* More articles by this author , David TzouDavid Tzou More articles by this author , David BayneDavid Bayne More articles by this author , Scott WienerScott Wiener More articles by this author , Adam GadzinskiAdam Gadzinski More articles by this author , Ian MetzlerIan Metzler More articles by this author , Kelly WalkerKelly Walker More articles by this author , Marshall StollerMarshall Stoller More articles by this author , and Tom ChiTom Chi More articles by this author View All Author Informationhttps://doi.org/10.1097/01.JU.0000555996.87122.1dAboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVES: Ultrasound (US) use during percutaneous nephrolithomy (PCNL) is becoming increasingly adopted by American urologists. Evaluation of attending physician's learning curve in adopting an US-guided renal puncture & dilation previously has been undertaken. Wide-spread adoption is expected as exposure to ultrasound directed renal puncture during urologic training increases, but how to effectively obtain mastery during training will require investigation. The aim of our study was to evaluate the urologic trainee's learning curve in successfully obtaining renal access under US-guidance. METHODS: Patients undergoing US-guided PCNL at a single academic urology training program between 5/2016 & 3/2018 were evaluated including cases where a resident attempted tract access. The primary endpoint measured was success of the trainee in obtaining ultrasound-guided renal access. A failed attempt was defined by the attending physician successfully obtaining renal access instead, or any use of fluoroscopy. RESULTS: 65 US-guided renal punctures were performed. Renal punctures were attempted by junior residents (PGY-2 & 3), senior residents (PGY-4), & chief residents (PGY-6) on 18, 32, & 15 cases, respectively. There were no differences in patient characteristics. PGY-4 performed the most puncture attempts. There were no differences in successful attempts between junior, senior, & chief residents. Consecutive US-guided renal access attempts were followed for 3 residents (AG n=9; IM n=8; KW n=7). The proportions of successful attempts for the 1st, 2nd, & 3rd tertile of cases were 100%, 100%, & 33%, for AG (P > 0.10), 100%, 33%, & 50% for IM (P > 0.10), & 66%, 66%, 0%, for KW (P > 0.10). CONCLUSIONS: US-guided renal access can be performed successfully by residents at any level of urology training. At our institution, most US-guided puncture attempts are performed as a PGY-4 though the puncture success rate was constant across all years. More US renal punctures as a junior resident may improve success rates as a PGY-4 & PGY-6. Learning can be further enhanced through surgical skill simulations. Future investigations will address these questions. Source of Funding: NIH P20-DK-116193, NIH R21-DK-109433, NIH TL1-TR-001871, Urology Care Foundation Student Fellowship San Francisco, CA© 2019 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 201Issue Supplement 4April 2019Page: e506-e507 Advertisement Copyright & Permissions© 2019 by American Urological Association Education and Research, Inc.MetricsAuthor Information Manuel Armas-Phan* More articles by this author David Tzou More articles by this author David Bayne More articles by this author Scott Wiener More articles by this author Adam Gadzinski More articles by this author Ian Metzler More articles by this author Kelly Walker More articles by this author Marshall Stoller More articles by this author Tom Chi More articles by this author Expand All Advertisement PDF downloadLoading ...

radio-lucent stone).The calculated followup cost was $23 for nurse led telephone clinics and $68 for face-to-face outpatient consultant reviews.The patients on the nurse-led pathway knew that a recurrence of symptoms or stone growth/recurrence or their personal preference would prompt a repeat clinic consultation.RESULTS: A total of 227 patients (39-49 annually) were referred to the virtual stone clinic for follow-up and surveillance of kidney stones with a mean age of 57 (range: 16-94) and a male:female ratio of 5:4.Of these 2 (1%) declined a virtual follow-up and preferred a face-to-face consultation.Over a mean follow-up of 1.1 years (range 6 months e 2 years), 63 (28%) have been discharged, 114 (50%) continue to be in the virtual clinic, 7 (4%) missed their follow-up and 41 (18%) returned to face-to-face clinical consultation due to recurrence of symptoms or stone growth/recurrence.The imaging modality was with plain KUB XR in 79% and USS in 21% with 34 (15%) patients having more than one follow-up.Based on our model, the overall cost of follow-up reduced by a third from $17,750 to $5,920 over the study period.CONCLUSIONS: Majority of patients were happy for a virtual nurse led telephone clinic follow-up and half of them continue to be followed this way.Based on the clinical needs, this allowed some patients to be either discharged or returned for a face-to-face clinical consultation.This model not only provided a safe follow-up but also allowed to lower the cost by a third which helps to optimise healthcare resources and reduce the overall cost of treatment.

You have accessJournal of UrologyImaging/Radiology: Uroradiology III (MP80)1 Apr 2019MP80-16 PERCUTANEOUS RENAL TRACT DILATION CAN BE SAFELY GUIDED UNDER ULTRASOUND IMAGING Manuel Armas-Phan*, David Tzou, David Bayne, Scott Wiener, Tim Liang, Marshall Stoller, and Tom Chi Manuel Armas-Phan*Manuel Armas-Phan* More articles by this author , David TzouDavid Tzou More articles by this author , David BayneDavid Bayne More articles by this author , Scott WienerScott Wiener More articles by this author , Tim LiangTim Liang More articles by this author , Marshall StollerMarshall Stoller More articles by this author , and Tom ChiTom Chi More articles by this author View All Author Informationhttps://doi.org/10.1097/01.JU.0000557415.42088.d7AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVES: Reducing radiation exposure to patients & staff during medical procedures is a growing area of importance. Ultrasound (US)-guided percutaneous nephrolithotomy (PCNL) is becoming increasingly adopted by American urologists. The aim of this study was to compare the clinical outcomes between fluoroscopic & non-fluoroscopic guided tract dilation for PCNL. METHODS: A prospective cohort study enrolled successive patients undergoing PCNL between 7/2015 & 3/2018. Included were those with a successful US-guided renal puncture. Patients were divided based on whether tract dilation was performed with fluoroscopy or not. The outcomes of interest were complications, EBL, & stone clearance. Differences were compared using Welch's t-test, Fisher's exact test, and regression modeling with Stata v15.1. RESULTS: 177 patients underwent PCNL including those with successful US-guided renal puncture. 38 & 139 underwent renal tract dilation with & without fluoroscopic guidance, respectively. There were no differences in age, gender, BMI, presence of hydronephrosis, stone size, procedure laterality, number of dilated tracts, & calyx puncture location. There was a larger proportion of modified dorsal lithotomy positions (49% v. 24%) & a shorter operative time (117min v. 138min) among non-fluoroscopic tract dilations. With multivariate regression analysis, only modified dorsal lithotomy remained statistically significantly different between the two groups. There were no differences in postoperative stone clearance, complications, or intraoperative EBL. For the entire cohort, a 5-unit increase in BMI had 30% greater odds of more severe Clavien-Dindo complications (p < 0.05) & 5mm decrease in the stone burden had 10% greater odds of achieving stone clearance (p < 0.05). No variables were predictive of EBL. CONCLUSIONS: Renal tract dilation can be safely performed in the absence of fluoroscopic guidance. Compared to using fluoroscopy, our study demonstrated that ultrasound-guided dilations can be safely performed without higher complication or bleeding rates. This can be performed using a variety of surgical positions, & future studies centered on improving dilation techniques could be of impactful clinical value. Source of Funding: NIH P20-DK-116193, NIH R21-DK-109433, NIH TL1-TR-001871, & Urology Care Foundation Medical Student Fellowship San Francisco, CA© 2019 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 201Issue Supplement 4April 2019Page: e1168-e1168 Advertisement Copyright & Permissions© 2019 by American Urological Association Education and Research, Inc.MetricsAuthor Information Manuel Armas-Phan* More articles by this author David Tzou More articles by this author David Bayne More articles by this author Scott Wiener More articles by this author Tim Liang More articles by this author Marshall Stoller More articles by this author Tom Chi More articles by this author Expand All Advertisement PDF downloadLoading ...

You have accessJournal of UrologyStone Disease: Surgical Therapy VI (MP79)1 Apr 2019MP79-02 PCNL: A SAFE ALTERNATIVE TO GUIDELINE RECOMMENDATIONS FOR STONES LESS THAN 1CM David Bayne*, Manuel Armas-Phan, Scott Wiener, Weiguo Hu, Bo Xiao, Boxing Su, Wenjie Bai, Marshall Stoller, Tom Chi, and Jianxing Li David Bayne*David Bayne* More articles by this author , Manuel Armas-PhanManuel Armas-Phan More articles by this author , Scott WienerScott Wiener More articles by this author , Weiguo HuWeiguo Hu More articles by this author , Bo XiaoBo Xiao More articles by this author , Boxing SuBoxing Su More articles by this author , Wenjie BaiWenjie Bai More articles by this author , Marshall StollerMarshall Stoller More articles by this author , Tom ChiTom Chi More articles by this author , and Jianxing LiJianxing Li More articles by this author View All Author Informationhttps://doi.org/10.1097/01.JU.0000557354.14401.c2AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVES: AUA guidelines recommend shockwave lithotripsy (SWL) or ureteroscopy (URS) for symptomatic lower pole renal stones < 10mm and non-lower pole renal stones < 20mm. We hypothesize that percutaneous nephrolithotomy (PCNL) can be performed safely in patients with stones < 10mm with minimal risk of complication and higher stone free rate compared to URS or SWL. Using an international stone registry we investigated the stone free and complication rates after PCNL for stones < 10mm relative to URS and/or SWL, and to determine international practice pattern differences in PCNL utilization. METHODS: Prospectively collected international data from the Registry for Stones of the Kidney and Ureter (ReSKU) composed of patients from the United States and China between September 2015 to July 2018 were investigated to evaluate characteristics of surgical patients treated for stones <10mm. Data on patient age, gender, BMI, stone location, delay to surgery, complication and transfusion rates, and stone clearance efficiency were analyzed. Univariate analysis was performed using Fisher's Exact test and Welch Two Sample t-test. Multivariate analysis was performed using logistic regression. Statistical analysis was performed in R version 3.3.3. RESULTS: A total of 2329 surgical stone procedures were undertaken; 303 procedures for stones < 10mm were identified. Multivariate analysis revealed that older age (p=0.028, OR 0.97 per year) was associated with lower likelihood of PCNL for stones < 10mm. Surgery performed in China was associated with higher rate of PCNL for stones < 10mm (p=0.002, OR 5.26). There were no differences in complication or transfusion rates. Stone clearance was higher in patients undergoing PCNL (93% vs 82%; p=0.103) but this was not statistically significant. CONCLUSIONS: When controlling for other variables, PCNL for stones <10mm is more commonly performed in younger patients and in China. There is no difference in complications or transfusion rates when comparing patients undergoing PCNL versus URS or SWL. International differences in surgical practice patterns may be explained by availability and comfort performing flexible ureteroscopy. In centers with a high volume of PCNL procedures, using this approach for small stones can be performed safely with no difference in complication rates relative to other procedures. Source of Funding: NIH grant P20-DK-116193 San Francisco, CA; Bejing, China, People’s Republic of; San Francisco, CA; Bejing, China, People’s Republic of© 2019 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 201Issue Supplement 4April 2019Page: e1152-e1152 Advertisement Copyright & Permissions© 2019 by American Urological Association Education and Research, Inc.MetricsAuthor Information David Bayne* More articles by this author Manuel Armas-Phan More articles by this author Scott Wiener More articles by this author Weiguo Hu More articles by this author Bo Xiao More articles by this author Boxing Su More articles by this author Wenjie Bai More articles by this author Marshall Stoller More articles by this author Tom Chi More articles by this author Jianxing Li More articles by this author Expand All Advertisement PDF downloadLoading ...

You have accessJournal of UrologyStone Disease: Medical & Dietary Therapy (MP12)1 Apr 2019MP12-13 THE CYSTINURIC DIET’S IMPACT ON SYMPTOMATIC STONE EPISODES Manuel Armas-Phan*, David Bayne, Scott Wiener, Tim Liang, Jeremy Goodman, Marshall Stoller, and Tom Chi Manuel Armas-Phan*Manuel Armas-Phan* More articles by this author , David BayneDavid Bayne More articles by this author , Scott WienerScott Wiener More articles by this author , Tim LiangTim Liang More articles by this author , Jeremy GoodmanJeremy Goodman More articles by this author , Marshall StollerMarshall Stoller More articles by this author , and Tom ChiTom Chi More articles by this author View All Author Informationhttps://doi.org/10.1097/01.JU.0000555206.36732.a6AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVES: Cystinurics suffer from impaired reabsorption of dibasic amino acids & recurrent calculi with lengthy periods of quiescence interrupted by periods with multiple frequent symptomatic stone episodes. How diet impacts these two different time periods remains unclear. Literature suggests protein, methionine, & sodium consumption can alter quantitative urinary cystine levels. This study aimed to determine the impact of dietary input associated with symptomatic stones in need of surgery. METHODS: Cystinuric patients were recruited for a food frequency & activity questionnaire (NutritionQuest) from an ongoing single site randomized control trial evaluating a novel medical intervention for cystinuria. All patients enrolled in the trial were contacted & respondents were divided into two groups defined as those who had undergone stone surgery within the last 2 years or not. Differences were compared using Wilcoxon rank-sum & Fisher's exact tests on Stata v15.1. RESULTS: 15 patients completed the questionnaire, of whom 6 had undergone stone surgery within 2 years of study enrollment. There were no differences between the groups with respect to age, gender, race, education, or BMI. 6 patients reported recent symptoms, 4 of which culminated in recent stone surgery. There were no differences in caloric, carbohydrate, & fat intake. Those who had recently undergone stone surgery consumed more daily protein (65.9g v. 50.7g), cysteine precursors (serine & methionine: 3.0g v 2.4g & 1.5 v 1.1g, respectively), & cysteine (0.9g v 0.7g) but these differences were not statistically significant (P < 0.10). Cystinurics with recent stone surgery consumed more sodium (3.2g v 2.2g) (p < 0.05) & had an increased oxalic acid consumption (230mg v. 150mg) (p < 0.01). There were no differences in water intake (2.4L v. 2.2L). CONCLUSIONS: To the best of our knowledge, this is the first attempt to assess diet's role in culminating in symptomatic cystine stone disease requiring surgical intervention. Interestingly, cystinurics who recently experienced stone surgery consumed more protein, minerals, & oxalic acid suggesting that consumption of these dietary components may tip cystinuric patients from quiescent periods to times where surgery is required. Future investigations utilizing this questionnaire will be performed to refine relationships between dietary inputs & cystinuric outcomes. Source of Funding: NIH P20-DK-100863, P20-DK-116193, R01-FD-005716, NIH TL1-TR-001871, & Urology Care Foundation Medical Student Fellowship San Francisco, CA© 2019 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 201Issue Supplement 4April 2019Page: e173-e174 Advertisement Copyright & Permissions© 2019 by American Urological Association Education and Research, Inc.MetricsAuthor Information Manuel Armas-Phan* More articles by this author David Bayne More articles by this author Scott Wiener More articles by this author Tim Liang More articles by this author Jeremy Goodman More articles by this author Marshall Stoller More articles by this author Tom Chi More articles by this author Expand All Advertisement PDF downloadLoading ...