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MP19-15 THE RELATIONSHIP BETWEEN HYPERURICEMIA AND URIC-ACID STONE FOR RENAL FUNCTION DETERIORATION: A POPULATION-BASED ANALYSIS
THE JOURNAL OF UROLOGYâ
Vol. 197, No. 4S, Supplement, Friday, May 12, 2017
e235
MP19-14 MECHANISTIC EVIDENCE THAT PAPILLARY PITS OCCUR SECONDARY TO DISLODGEMENT OF RANDALL’S PLAQUE ATTACHED STONES Michael S. Borofsky*, Minneapolis, MN; James C. Williams, Jr. Indianapolis, IN; Elaine M. Worcester, Chicago, IL; Casey A. Dauw, Ann Arbor, MI; Nadya E. York, Andrew P. Evan, James E. Lingeman, Indianapolis, IN INTRODUCTION AND OBJECTIVES: Renal papillary characteristics among stone formers are suspected to have associations with stone forming pathophysiologies. Papillary pitting (surface erosion) is one of the most common abnormalities encountered and is a component of both recently described papillary classification systems. To date, the mechanism by which pitting occurs is unclear. One hypothesis is that pits are sites where stones overgrowing Randall’s plaque (RP) became dislodged. We sought to examine this hypothesis using stone micro CT and high definition renal endoscopy. METHODS: Patients undergoing endoscopic stone removal had their procedures recorded and stones analyzed using micro CT. Patients with stones showing evidence of RP attachment were identified in a manner blinded to patient data. Corresponding surgical videos were reviewed independently by 2 urologists to characterize the RP/ renal stone interface and look for papillary pitting. RESULTS: RP attachments were identified on micro CT in 28 patients (Figure 1). 7.3 RP stones were removed per patient, the majority of whom were recurrent stone formers (93%) with history of prior stone treatment (75%) (Table 1). A majority of patients were categorized as idiopathic calcium oxalate stone formers (78.5%) and metabolic abnormalities on 24 hour urine chemistry were common (86.4%). Pits were identified prior to any stone manipulation on at least one papilla in all cases including 7 who had had no prior procedures (Figure 2). CONCLUSIONS: Stones growing over RP likely pull a piece of tissue away from the papilla when dislodged, leaving visible papillary pits. Identification of pits and incorporation into endoscopic characterization systems for stone formers may help improve patient classification.
Source of Funding: NIH DK056788
MP19-15 THE RELATIONSHIP BETWEEN HYPERURICEMIA AND URIC-ACID STONE FOR RENAL FUNCTION DETERIORATION: A POPULATION-BASED ANALYSIS Toshikazu Tanaka*, Shingo Hatakeyama, Yuriko Terayama, Fumitada Saitoh, Hisao Saitoh, Yasuhiro Hashimoto, Takuya Koie, Chikara Ohyama, Hirosaki, Japan INTRODUCTION AND OBJECTIVES: Although both hyperuricemia and uric-acid (UA) stone are potential risk factors for
THE JOURNAL OF UROLOGYâ
e236
Chronic Kidney Disease (CKD), it remains unclear which factor has much more worse effects on renal function. We accessed the influence of hyperuricemia on impaired renal function in patients with UA stone components in comparison with community-dwelling population. METHODS: Between 2010 and 2014, we treated 1793 consecutive patients with urolithiasis in our hospital, and identified stone components available 473 patients. Of those, 123 patients with UA stone were included in the present study. Age, sex, and serum UA concentration adjusted control subjects were selected from 3089 community-dwelling population in each group by propensityscore matching (2:1). Subjects were divided into two groups; hyperuricemia or non-hyperuricemia groups according to the serum UA concentrations (UA-low: < 7.0 or UA-high: ¼7.0 mg/mL). We compared renal function between the UA stone and control subjects in each group. The renal function was evaluated as estimated glomerular filtration rate (eGFR). The independent risk factor for impaired renal function were investigated by multivariate logistic regression analysis. RESULTS: We selected pair-matched 166 control subjects and 83 UA stone patients for serum UA-low group. Similarly, 68 control subjects and 34 UA stone patients for serum UA-high group. UA stone patients had significantly lower in eGFR (P<0.01) compared with control subjects regardless of serum UA concentrations. Multivariate logistic regression analysis revealed that age, past-history of cardiovascular disease, serum UA, and stone former were significant factors for stage 3 CKD. UA stone component had 3-fold chance to develop stage 3 CKD than serum UA concentration. CONCLUSIONS: Uric acid stone components may strongly influence on renal function deterioration than hyperuricemia.
Vol. 197, No. 4S, Supplement, Friday, May 12, 2017
the Gaussian distribution. Using scores from a previously introduced and validated papillary grading system, we sought to test if this is true. METHODS: We reduced papillary grading scores from patients who had undergone unilateral ureteroscopic stone treatment to 00 present00 or 00 absent00 for each variable in the grading system - pitting, plugging, loss of contour, and RP. From this we calculated the proportion of graded papillae in a given kidney involved. Probability density functions were generated and Shapiro-Wilks (SW) and AndersonDarling AD) tests of normality were applied. RESULTS: Our cohort included 42 patients (42 kidneys), all of whom had calcium stones - 28 calcium oxalate and 14 calcium phosphate - on subsequent analysis. The mean number of papilla graded per kidney was 5.97 (95% CI 5.40-6.55). The mean proportion of papillae with plugging was 51.7% (4.3), pitting was 20.1% (3.0), loss of contour was 22.7% (3.6), and RP was 33.7% (4.0). Probability density functions are shown in Figure 1. Unlike pitting, loss of contour, and RP, plugging is uniquely normally distributed (SW and AD tests p>0.01). CONCLUSIONS: Unlike pitting, loss of contour, and RP, plugging is uniquely normally distributed (SW and AD tests p>0.01), supporting that plugging is a random and independent process in individual papillae and plaque, pitting, and contour changes cannot be.
Source of Funding: none
Source of Funding: none
MP19-16 RENAL PAPILLARY PLUGGING IN CALCIUM STONE FORMERS MAY ARISE VIA RANDOM AND INDEPENDENT CRYSTALLIZATION EVENTS Melanie Adamsky*, Andrew Cohen, Glenn Gerber, Elaine Worcester, Frederic Coe, Chicago, IL INTRODUCTION AND OBJECTIVES: The causes of renal papillary abnormalities observed endoscopically within a single kidney are incompletely known. One testable theory is that plugging, and perhaps Randall’s plaque (RP), are random and independent events of crystallization whose risk is increased by local supersaturations. If so, their occurrence in the papillae of a kidney must follow
MP19-17 RENAL PAPILLARY MAPPING AND QUANTIFICATION OF RANDALL’S PLAQUE IN PEDIATRIC CALCIUM OXALATE STONE FORMERS Annie Darves-Bornoz*, John Thomas, Tracy Marien, Gabriel Fiscus, Douglass Clayton, Nicole Miller, Nashville, TN INTRODUCTION AND OBJECTIVES: Randall’s plaque (RP) with attached stones is recognized as a primary mechanism for stone formation in adult calcium oxalate stone formers (CaOx SF). The role of RP in pediatric stone pathogenesis is unknown, with no reported studies to date. The purpose of this study is to investigate renal papillary abnormalities and quantify RP in pediatric CaOx SF. METHODS: 8 pediatric CaOx SF underwent ureteroscopy for symptomatic urolithiasis. The collecting system was mapped using a digital ureteroscope. Video for each patient was then reviewed
Vol. 197, No. 4S, Supplement, Friday, May 12, 2017
e235
MP19-14 MECHANISTIC EVIDENCE THAT PAPILLARY PITS OCCUR SECONDARY TO DISLODGEMENT OF RANDALL’S PLAQUE ATTACHED STONES Michael S. Borofsky*, Minneapolis, MN; James C. Williams, Jr. Indianapolis, IN; Elaine M. Worcester, Chicago, IL; Casey A. Dauw, Ann Arbor, MI; Nadya E. York, Andrew P. Evan, James E. Lingeman, Indianapolis, IN INTRODUCTION AND OBJECTIVES: Renal papillary characteristics among stone formers are suspected to have associations with stone forming pathophysiologies. Papillary pitting (surface erosion) is one of the most common abnormalities encountered and is a component of both recently described papillary classification systems. To date, the mechanism by which pitting occurs is unclear. One hypothesis is that pits are sites where stones overgrowing Randall’s plaque (RP) became dislodged. We sought to examine this hypothesis using stone micro CT and high definition renal endoscopy. METHODS: Patients undergoing endoscopic stone removal had their procedures recorded and stones analyzed using micro CT. Patients with stones showing evidence of RP attachment were identified in a manner blinded to patient data. Corresponding surgical videos were reviewed independently by 2 urologists to characterize the RP/ renal stone interface and look for papillary pitting. RESULTS: RP attachments were identified on micro CT in 28 patients (Figure 1). 7.3 RP stones were removed per patient, the majority of whom were recurrent stone formers (93%) with history of prior stone treatment (75%) (Table 1). A majority of patients were categorized as idiopathic calcium oxalate stone formers (78.5%) and metabolic abnormalities on 24 hour urine chemistry were common (86.4%). Pits were identified prior to any stone manipulation on at least one papilla in all cases including 7 who had had no prior procedures (Figure 2). CONCLUSIONS: Stones growing over RP likely pull a piece of tissue away from the papilla when dislodged, leaving visible papillary pits. Identification of pits and incorporation into endoscopic characterization systems for stone formers may help improve patient classification.
Source of Funding: NIH DK056788
MP19-15 THE RELATIONSHIP BETWEEN HYPERURICEMIA AND URIC-ACID STONE FOR RENAL FUNCTION DETERIORATION: A POPULATION-BASED ANALYSIS Toshikazu Tanaka*, Shingo Hatakeyama, Yuriko Terayama, Fumitada Saitoh, Hisao Saitoh, Yasuhiro Hashimoto, Takuya Koie, Chikara Ohyama, Hirosaki, Japan INTRODUCTION AND OBJECTIVES: Although both hyperuricemia and uric-acid (UA) stone are potential risk factors for
THE JOURNAL OF UROLOGYâ
e236
Chronic Kidney Disease (CKD), it remains unclear which factor has much more worse effects on renal function. We accessed the influence of hyperuricemia on impaired renal function in patients with UA stone components in comparison with community-dwelling population. METHODS: Between 2010 and 2014, we treated 1793 consecutive patients with urolithiasis in our hospital, and identified stone components available 473 patients. Of those, 123 patients with UA stone were included in the present study. Age, sex, and serum UA concentration adjusted control subjects were selected from 3089 community-dwelling population in each group by propensityscore matching (2:1). Subjects were divided into two groups; hyperuricemia or non-hyperuricemia groups according to the serum UA concentrations (UA-low: < 7.0 or UA-high: ¼7.0 mg/mL). We compared renal function between the UA stone and control subjects in each group. The renal function was evaluated as estimated glomerular filtration rate (eGFR). The independent risk factor for impaired renal function were investigated by multivariate logistic regression analysis. RESULTS: We selected pair-matched 166 control subjects and 83 UA stone patients for serum UA-low group. Similarly, 68 control subjects and 34 UA stone patients for serum UA-high group. UA stone patients had significantly lower in eGFR (P<0.01) compared with control subjects regardless of serum UA concentrations. Multivariate logistic regression analysis revealed that age, past-history of cardiovascular disease, serum UA, and stone former were significant factors for stage 3 CKD. UA stone component had 3-fold chance to develop stage 3 CKD than serum UA concentration. CONCLUSIONS: Uric acid stone components may strongly influence on renal function deterioration than hyperuricemia.
Vol. 197, No. 4S, Supplement, Friday, May 12, 2017
the Gaussian distribution. Using scores from a previously introduced and validated papillary grading system, we sought to test if this is true. METHODS: We reduced papillary grading scores from patients who had undergone unilateral ureteroscopic stone treatment to 00 present00 or 00 absent00 for each variable in the grading system - pitting, plugging, loss of contour, and RP. From this we calculated the proportion of graded papillae in a given kidney involved. Probability density functions were generated and Shapiro-Wilks (SW) and AndersonDarling AD) tests of normality were applied. RESULTS: Our cohort included 42 patients (42 kidneys), all of whom had calcium stones - 28 calcium oxalate and 14 calcium phosphate - on subsequent analysis. The mean number of papilla graded per kidney was 5.97 (95% CI 5.40-6.55). The mean proportion of papillae with plugging was 51.7% (4.3), pitting was 20.1% (3.0), loss of contour was 22.7% (3.6), and RP was 33.7% (4.0). Probability density functions are shown in Figure 1. Unlike pitting, loss of contour, and RP, plugging is uniquely normally distributed (SW and AD tests p>0.01). CONCLUSIONS: Unlike pitting, loss of contour, and RP, plugging is uniquely normally distributed (SW and AD tests p>0.01), supporting that plugging is a random and independent process in individual papillae and plaque, pitting, and contour changes cannot be.
Source of Funding: none
Source of Funding: none
MP19-16 RENAL PAPILLARY PLUGGING IN CALCIUM STONE FORMERS MAY ARISE VIA RANDOM AND INDEPENDENT CRYSTALLIZATION EVENTS Melanie Adamsky*, Andrew Cohen, Glenn Gerber, Elaine Worcester, Frederic Coe, Chicago, IL INTRODUCTION AND OBJECTIVES: The causes of renal papillary abnormalities observed endoscopically within a single kidney are incompletely known. One testable theory is that plugging, and perhaps Randall’s plaque (RP), are random and independent events of crystallization whose risk is increased by local supersaturations. If so, their occurrence in the papillae of a kidney must follow
MP19-17 RENAL PAPILLARY MAPPING AND QUANTIFICATION OF RANDALL’S PLAQUE IN PEDIATRIC CALCIUM OXALATE STONE FORMERS Annie Darves-Bornoz*, John Thomas, Tracy Marien, Gabriel Fiscus, Douglass Clayton, Nicole Miller, Nashville, TN INTRODUCTION AND OBJECTIVES: Randall’s plaque (RP) with attached stones is recognized as a primary mechanism for stone formation in adult calcium oxalate stone formers (CaOx SF). The role of RP in pediatric stone pathogenesis is unknown, with no reported studies to date. The purpose of this study is to investigate renal papillary abnormalities and quantify RP in pediatric CaOx SF. METHODS: 8 pediatric CaOx SF underwent ureteroscopy for symptomatic urolithiasis. The collecting system was mapped using a digital ureteroscope. Video for each patient was then reviewed