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MP20-18 PROGRESS TOWARDS A PRACTICAL PROTOCOL TO MINIMIZE RENAL INJURY IN EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY
THE JOURNAL OF UROLOGYâ
e202
euthanized, kidneys explanted and dissected to separate cortex and medulla. Total RNA was isolated and microarray analysis was conducted on the renal cortical and medullary tissues using the Illumina bead array reader TM. Gene ontology (GO) analysis and the pathway analysis of the genes were carried out using DAVID (Database for Annotation, Visualization of Integrated Discovery) enrichment analysis tool. Immunohistochemistry and RT-PCR were used to confirm expressions of selected gene products. RESULTS: Administration of HLP led to calcium oxalate crystal deposition in the kidneys. Deposits ranged from few scattered crystals to heavy deposit in the cortical tubules. Apocynin treatment resulted in near complete absence of crystals, despite showing similar urinary oxalate. Genes encoding for alpha-1 and alpha-2-microglobulin, fibronectin, CD 44, osteonectin, fetuin B, osteopontin, and matrix-gla protein, were up-regulated in both cortex and medulla. On the other hand, genes encoding for inter-alpha-inhibitor 1, 3 and 4, calgranulin B, coagulation factor-2 (prothrombin), and Tamm-Horsfall protein were down-regulated in both cortex and medulla. HLP-fed rats receiving apocynin had a significant reversal in gene expression profiles, those that were upregulated came down while those that were down-regulated stepped up. CONCLUSIONS: Calcium oxalate crystal deposition in the kidneys alters gene expression and production of all the known crystallization modulators. Apparently reactive oxygen species and NADPH oxidase are involved in regulation of MM gene expression. Clearly, there are two distinct kinds of MMs, some are down-regulated while the others are up-regulated during hyperoxaluria and crystal deposition in the kidneys. Source of Funding: NIH grant #RO1-DK078602
MP20-16 INTERIM RESULTS OF A RANDOMIZED TRIAL COMPARING NARROW VERSUS WIDE FOCAL ZONES FOR SHOCK WAVE LITHOTRIPSY OF RENAL CALCULI R. J. D'. A. Honey, Tarek Alzahrani*, Daniela Ghiculete, Kenneth T. Pace, Toronto, Canada INTRODUCTION AND OBJECTIVES: The Modulith SLK-F2 electromagnatic lithotripter (Storz Medical) is the first lithotripter on the market with a unique design that allows for a dual focus system with the option of either a narrow (6x28 mm) or wide (9x50 mm) focal zone. Ex vivo data shows that disintegration capacity and renal vascular injury are independent of the focal diameter of the SW generator at the same peak pressure and disintegration power. The objective of this study is to compare the single-treatment success rates of narrow and wide focal zones for the shock wave lithotripsy (SWL) of renal stones. METHODS: 118 patients with a previously untreated radioopaque solitary stone located within the renal collecting system, measuring 5 to 15 mm in greatest diameter, were randomized to receive narrow or wide focus lithotripsy. Patients were followed with KUB x-rays and renal ultrasound at 2 and 12 weeks post lithotripsy to assess stone free status. Urinary markers indicating the degree of renal cellular damage (microalbumin and Beta-2 macroglobulin) were measured preand post-SWL, 24 hours post-SWL and 7 days post-treatment. Primary outcome was single-treatment success rate, defined as stone-free or adequate fragmentation (sand and asymptomatic fragments <¼4mm) at 3 months post-treatment. RESULTS: 61 (51.7%) patients were randomized to narrow focus lithotripsy versus 57 (48.3%) patients wide focus. The groups were similar in baseline characteristics including (age, gender, BMI, stone size and density and skin to stone distance). The overall success rates were not significantly different at 2 weeks post treatment (Narrow: 72.1% vs Wide: 61.4%; P ¼ 0.216) nor at 3 months (Narrow: 68.3% vs Wide: 58.9%; P ¼ 0.292). The overall complication rates was also comparable in the two groups (Narrow: 24.6% vs Wide: 17.5%; P ¼ 0.349) including similar rates of perinephric hematoma (Narrow: 3.3% vs Wide: 3.5%; P ¼ 0.945). The microalbumin-to-creatinine ratio was
Vol. 191, No. 4S, Supplement, Saturday, May 17, 2014
significantly different between the two groups (p¼0.019), but that difference was gone within 24 hours after the treatment. CONCLUSIONS: Interim results indicated that single-treatment success rate and complications are comparable when using the narrow or wide focus of the Modulith SLX-F2. There was a difference in renal injury as measured bymicroalbumin to creatinine ratio (with lower values in the narrow focal zone group), but these differences disappeared within 24h of treatment. We are continuing to recruit patients to a pre-planned sample size of 300. Source of Funding: none
MP20-17 THE ACOUSTIC SHADOW WIDTH IS A MORE ACCURATE PREDICTOR OF TRUE STONE SIZE DURING ULTRASOUND Franklin Lee*, seattle, WA; Barbrina Dunmire, Seattle, WA; Jonathan Harper, Bryan Cunitz, Ryan Hsi, Michael Bailey, Mathew Sorensen, seattle, WA INTRODUCTION AND OBJECTIVES: While ultrasound is readily available, relatively less expensive than CT, and does not produce ionizing radiation; it is known to overestimate and inaccurately measure stone size. We explored the use of measuring the acoustic shadow behind kidney stones as a better predictor of true stone size. METHODS: 45 calcium oxalate monohydrate kidney stones ranging from 1-10 mm were imaged in a water bath using a researchbased ultrasound system with a C5-2 transducer. Stones were imaged at depths of 6, 10, and 14 cm. Under B-mode ultrasound, the width of both the stone and stone acoustic shadow was measured at each depth for every stone. Three blinded reviewers (2 urologists and an ultrasonagropher) independently performed each measurement. A linear mixed-effect model was used to account for within-stone correlations, and compare stone and shadow measurements for each size, depth, and user. Subgroup analysis was performed to determine the percentage of stones that were over-classified as greater than 5 mm when true stone size was less than 5 mm. RESULTS: Stone size was consistently overestimated when directly measuring stone width. Average overestimation was 1.10.8 mm, 1.91.0 mm, 2.71.4 mm at 6, 10, 14 cm depths, respectively. Overestimation increased with increasing depth (p<0.01). The acoustic shadow technique resulted in an overestimation of 0.20.8 mm, 0.01.1 mm, and 0.21.2 mm at 6, 10, 14 cm depths, respectively. The acoustic shadow technique was a better predictor of true stone size at all depths and sizes compared to measuring the stone width (p<0.001 at each depth). Subgroup analysis demonstrated that over-classification occurred in 15/60 (25%) when the stone was measured and 4/60 (7%) when measuring the posterior acoustic shadow. CONCLUSIONS: There is consistent overestimation using the stone width under B-mode ultrasound, with increasing overestimation with increasing depth. Use of the acoustic shadow width significantly reduces overestimation and decreases over-classification by 18% for stones less than 5 mm. Source of Funding: NIH DK43881 and DK092197, and NSBRI through NASA NCC 9-58.
MP20-18 PROGRESS TOWARDS A PRACTICAL PROTOCOL TO MINIMIZE RENAL INJURY IN EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY Bret Connors*, Andrew Evan, Rajash Handa, Philip Blomgren, Cynthia Johnson, James McAteer, James Lingeman, Indianapolis, IN INTRODUCTION AND OBJECTIVES: Previous studies with our juvenile pig model have shown that a clinical dose of 2000 shock waves (SWs) (Dornier HM-3, 24 kV, 120 SWs/min) produces a lesion measuring z3-5% of the functional renal volume (FRV) of that
THE JOURNAL OF UROLOGYâ
Vol. 191, No. 4S, Supplement, Saturday, May 17, 2014
kidney. We have also demonstrated that this injury can be significantly reduced (to z0.4% FRV) when the SWs are delivered at a slow SW-rate or when a priming dose of low-energy SWs is followed by a 3-4 minute pause (BJU Int 104:1004, 2009; BJU Int 110:E1041, 2012). Although such protocols are effective at reducing injury, few urologists have the flexibility to adopt procedures that increase the length of time devoted to treatment. Hence, we sought to identify a treatment protocol that would initiate significant protection against SW injury while limiting any increase in treatment time. To explore this idea we asked if using a pause-less protocol featuring only 300 priming dose SWs would initiate significant protection against injury. METHODS: Seven-week old juvenile pigs were treated with 300 SWs at 12 kV (120 SWs/min) delivered to a lower pole calyx using a HM-3 lithotripter. After a time pause of only 10 seconds to reset the power level, 2000 SWs at 24 kV were delivered to that same kidney. Four hours after the end of shock wave lithotripsy (SWL) the kidneys were perfusion fixed and then processed to quantitate the size of the parenchymal lesion. RESULTS: Pigs (n¼6) treated using a pause-less protocol including 300 low-energy priming dose SWs had a lesion measuring 0.770.55% FRV (mean SE). This lesion is smaller (and approaching significance) than the lesion size of 3.311.06% FRV seen when giving a clinical dose of 2000 SWs at 24 kV. CONCLUSIONS: While these data are preliminary, they indicate that treatment using a pause-less protocol including 300 lowenergy priming dose SWs shows promise as a protocol that provides both injury protection and a short treatment length. This information can be used to help formulate a practical SWL treatment protocol that can insure patient safety and can be easily adopted in the urology clinic. Source of Funding: NIH grant PO1 DK43881
MP20-19 SHOCKWAVE LITHOTRIPSY WITH RENOPROTECTIVE PAUSE IS ASSOCIATED WITH RENOVASCULAR VASOCONSTRICTION IN HUMANS Franklin Lee*, Ryan Hsi, Mathew Sorensen, Marla Paun, Seattle, WA; Barbrina Dunmire, Seattle, WA; Ziyue Liu, Bloomington, IN; Michael Bailey, Jonathan Harper, Seattle, WA INTRODUCTION AND OBJECTIVES: During shockwave lithotripsy (SWL), pre-treatment with low-energy shocks followed by a 3minute pause mitigates renal injury in an animal model. In the same model, the pause is associated with an increase in resistive index (RI), suggesting that renal vasoconstriction leads to protection from kidney injury. The purpose of our study was to investigate whether this association is observed in humans. METHODS: Patients were prospectively recruited from two hospitals. All underwent SWL of renal stones with a Dornier Compact S lithotripter at 1 Hz and received an initial 250 shocks at the lowest power setting followed by a 2 minute pause. Treatment power was then ramped up after the pause while maintaining the 1 Hz shock frequency with the total shocks delivered at the discretion of the operating surgeon. RIs were measured using ultrasound at baseline after induction, during the pause at 250 shocks, after 750 shocks, 1500 shocks, and at the end of the procedure. A linear mixed-effects model was used to compare RI at the different timepoints and to account for additional covariates including age, gender, laterality, and body mass index (BMI).
e203
RESULTS: 15 patients (4 female, 11 male) were enrolled with mean age of 61 15 years and average BMI of 29 5 kg/m2. Average stone size was 10.4 7.7 mm with average treatment time of 45 9.7 minutes. Average RI pretreatment, after 250 shocks, 750 shocks, 1500 shocks, and post-treatment were 0.680.06, 0.710.07, 0.730.06, 0.750.07 and 0.750.06, respectively. RI was found to be significantly higher post-treatment compared to pre-treatment (p<0.001) with a significant rise starting after 250 shocks (p¼0.04). After 750 shocks, the RI stabilized and did not increase further (p¼0.17). Age, gender, BMI, and treatment side, did not significantly affect RI. CONCLUSIONS: The SWL protocol with a renoprotective pause is associated with a rise in RI in humans occurring around 250 shocks into treatment. This suggests that allowing 4 to 5 minutes for renovascular vasoconstriction to develop may be beneficial. Monitoring for a rise in RI during SWL is possible and may provide real-time feedback as to when the kidney is protected. Source of Funding: NIH DK43881 and DK092197, and NSBRI through NASA NCC 9-58.
MP20-20 C-REACTIVE PROTEIN: IS IT THE END OF UNMERITED MEDICAL EXPULSIVE THERAPY? Altaf Khan*, Manjunath Shetty, Mangalore, India INTRODUCTION AND OBJECTIVES: C-Reactive Protein (CRP) is an acute phase reactant protein which is elevated in infections such as pyelonephritis. It was first used by the authors as marker of expulsive rate of single small (5-7mm) lower ureteric calculi. This is the continuation of the same study with inclusion of total white cell count and ESR and their association with the expulsive rate of small ureteric calculi. METHODS: A total of 500 patients with 5-7mm lower ureteric calculi with mild symptoms were included in the study during the period from Nov 2009-Oct 2013. All patients were investigated according to strict investigation protocol which included total count, ESR, CRP, S. Creat and NCCT abdomen and pelvis. Patients were subjected for medical treatment with alpha blockers (tamsulosin 0.4mg in patients >40yrs and alfuzosin 10mg in <40 yrs age group), diuretics and analgesics whenever required. Of the 500 patients, 239 had a CRP of <20, 157 had between 21-40 and 104 had CRP >40mg/L. Average stone size was comparable for all groups. RESULTS: Patients were followed up after 3 weeks of medical treatment. Patients were assessed for symptom relief, investigated with NCCT abdomen and pelvis. Of the 239 patients with CRP <20mg/L 202 (84.51%) had passed the stone on follow up. Of 157 patients with CRP between 20-40, 69(43.94%) had passed the stone. But of 104 patients with CRP >40 only 11(10.57%) had passed the stone. Patients with non expulsion of stone were subjected for Ureterorenoscopy and intracorporeal lithotripsy. It was found that there was no correlation between total wbc count and also ESR with expulsion rate of lower ureteric calculi. CONCLUSIONS: If we are racing towards evidence based urology then here we have a marker which may probably help us do away with un necessary medical expulsive therapy by predicting spontaneous passage rate of small lower ureteric calculi. Medical expulsive therapy can be discarded if the CRP is on the higher side. Source of Funding: none
e202
euthanized, kidneys explanted and dissected to separate cortex and medulla. Total RNA was isolated and microarray analysis was conducted on the renal cortical and medullary tissues using the Illumina bead array reader TM. Gene ontology (GO) analysis and the pathway analysis of the genes were carried out using DAVID (Database for Annotation, Visualization of Integrated Discovery) enrichment analysis tool. Immunohistochemistry and RT-PCR were used to confirm expressions of selected gene products. RESULTS: Administration of HLP led to calcium oxalate crystal deposition in the kidneys. Deposits ranged from few scattered crystals to heavy deposit in the cortical tubules. Apocynin treatment resulted in near complete absence of crystals, despite showing similar urinary oxalate. Genes encoding for alpha-1 and alpha-2-microglobulin, fibronectin, CD 44, osteonectin, fetuin B, osteopontin, and matrix-gla protein, were up-regulated in both cortex and medulla. On the other hand, genes encoding for inter-alpha-inhibitor 1, 3 and 4, calgranulin B, coagulation factor-2 (prothrombin), and Tamm-Horsfall protein were down-regulated in both cortex and medulla. HLP-fed rats receiving apocynin had a significant reversal in gene expression profiles, those that were upregulated came down while those that were down-regulated stepped up. CONCLUSIONS: Calcium oxalate crystal deposition in the kidneys alters gene expression and production of all the known crystallization modulators. Apparently reactive oxygen species and NADPH oxidase are involved in regulation of MM gene expression. Clearly, there are two distinct kinds of MMs, some are down-regulated while the others are up-regulated during hyperoxaluria and crystal deposition in the kidneys. Source of Funding: NIH grant #RO1-DK078602
MP20-16 INTERIM RESULTS OF A RANDOMIZED TRIAL COMPARING NARROW VERSUS WIDE FOCAL ZONES FOR SHOCK WAVE LITHOTRIPSY OF RENAL CALCULI R. J. D'. A. Honey, Tarek Alzahrani*, Daniela Ghiculete, Kenneth T. Pace, Toronto, Canada INTRODUCTION AND OBJECTIVES: The Modulith SLK-F2 electromagnatic lithotripter (Storz Medical) is the first lithotripter on the market with a unique design that allows for a dual focus system with the option of either a narrow (6x28 mm) or wide (9x50 mm) focal zone. Ex vivo data shows that disintegration capacity and renal vascular injury are independent of the focal diameter of the SW generator at the same peak pressure and disintegration power. The objective of this study is to compare the single-treatment success rates of narrow and wide focal zones for the shock wave lithotripsy (SWL) of renal stones. METHODS: 118 patients with a previously untreated radioopaque solitary stone located within the renal collecting system, measuring 5 to 15 mm in greatest diameter, were randomized to receive narrow or wide focus lithotripsy. Patients were followed with KUB x-rays and renal ultrasound at 2 and 12 weeks post lithotripsy to assess stone free status. Urinary markers indicating the degree of renal cellular damage (microalbumin and Beta-2 macroglobulin) were measured preand post-SWL, 24 hours post-SWL and 7 days post-treatment. Primary outcome was single-treatment success rate, defined as stone-free or adequate fragmentation (sand and asymptomatic fragments <¼4mm) at 3 months post-treatment. RESULTS: 61 (51.7%) patients were randomized to narrow focus lithotripsy versus 57 (48.3%) patients wide focus. The groups were similar in baseline characteristics including (age, gender, BMI, stone size and density and skin to stone distance). The overall success rates were not significantly different at 2 weeks post treatment (Narrow: 72.1% vs Wide: 61.4%; P ¼ 0.216) nor at 3 months (Narrow: 68.3% vs Wide: 58.9%; P ¼ 0.292). The overall complication rates was also comparable in the two groups (Narrow: 24.6% vs Wide: 17.5%; P ¼ 0.349) including similar rates of perinephric hematoma (Narrow: 3.3% vs Wide: 3.5%; P ¼ 0.945). The microalbumin-to-creatinine ratio was
Vol. 191, No. 4S, Supplement, Saturday, May 17, 2014
significantly different between the two groups (p¼0.019), but that difference was gone within 24 hours after the treatment. CONCLUSIONS: Interim results indicated that single-treatment success rate and complications are comparable when using the narrow or wide focus of the Modulith SLX-F2. There was a difference in renal injury as measured bymicroalbumin to creatinine ratio (with lower values in the narrow focal zone group), but these differences disappeared within 24h of treatment. We are continuing to recruit patients to a pre-planned sample size of 300. Source of Funding: none
MP20-17 THE ACOUSTIC SHADOW WIDTH IS A MORE ACCURATE PREDICTOR OF TRUE STONE SIZE DURING ULTRASOUND Franklin Lee*, seattle, WA; Barbrina Dunmire, Seattle, WA; Jonathan Harper, Bryan Cunitz, Ryan Hsi, Michael Bailey, Mathew Sorensen, seattle, WA INTRODUCTION AND OBJECTIVES: While ultrasound is readily available, relatively less expensive than CT, and does not produce ionizing radiation; it is known to overestimate and inaccurately measure stone size. We explored the use of measuring the acoustic shadow behind kidney stones as a better predictor of true stone size. METHODS: 45 calcium oxalate monohydrate kidney stones ranging from 1-10 mm were imaged in a water bath using a researchbased ultrasound system with a C5-2 transducer. Stones were imaged at depths of 6, 10, and 14 cm. Under B-mode ultrasound, the width of both the stone and stone acoustic shadow was measured at each depth for every stone. Three blinded reviewers (2 urologists and an ultrasonagropher) independently performed each measurement. A linear mixed-effect model was used to account for within-stone correlations, and compare stone and shadow measurements for each size, depth, and user. Subgroup analysis was performed to determine the percentage of stones that were over-classified as greater than 5 mm when true stone size was less than 5 mm. RESULTS: Stone size was consistently overestimated when directly measuring stone width. Average overestimation was 1.10.8 mm, 1.91.0 mm, 2.71.4 mm at 6, 10, 14 cm depths, respectively. Overestimation increased with increasing depth (p<0.01). The acoustic shadow technique resulted in an overestimation of 0.20.8 mm, 0.01.1 mm, and 0.21.2 mm at 6, 10, 14 cm depths, respectively. The acoustic shadow technique was a better predictor of true stone size at all depths and sizes compared to measuring the stone width (p<0.001 at each depth). Subgroup analysis demonstrated that over-classification occurred in 15/60 (25%) when the stone was measured and 4/60 (7%) when measuring the posterior acoustic shadow. CONCLUSIONS: There is consistent overestimation using the stone width under B-mode ultrasound, with increasing overestimation with increasing depth. Use of the acoustic shadow width significantly reduces overestimation and decreases over-classification by 18% for stones less than 5 mm. Source of Funding: NIH DK43881 and DK092197, and NSBRI through NASA NCC 9-58.
MP20-18 PROGRESS TOWARDS A PRACTICAL PROTOCOL TO MINIMIZE RENAL INJURY IN EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY Bret Connors*, Andrew Evan, Rajash Handa, Philip Blomgren, Cynthia Johnson, James McAteer, James Lingeman, Indianapolis, IN INTRODUCTION AND OBJECTIVES: Previous studies with our juvenile pig model have shown that a clinical dose of 2000 shock waves (SWs) (Dornier HM-3, 24 kV, 120 SWs/min) produces a lesion measuring z3-5% of the functional renal volume (FRV) of that
THE JOURNAL OF UROLOGYâ
Vol. 191, No. 4S, Supplement, Saturday, May 17, 2014
kidney. We have also demonstrated that this injury can be significantly reduced (to z0.4% FRV) when the SWs are delivered at a slow SW-rate or when a priming dose of low-energy SWs is followed by a 3-4 minute pause (BJU Int 104:1004, 2009; BJU Int 110:E1041, 2012). Although such protocols are effective at reducing injury, few urologists have the flexibility to adopt procedures that increase the length of time devoted to treatment. Hence, we sought to identify a treatment protocol that would initiate significant protection against SW injury while limiting any increase in treatment time. To explore this idea we asked if using a pause-less protocol featuring only 300 priming dose SWs would initiate significant protection against injury. METHODS: Seven-week old juvenile pigs were treated with 300 SWs at 12 kV (120 SWs/min) delivered to a lower pole calyx using a HM-3 lithotripter. After a time pause of only 10 seconds to reset the power level, 2000 SWs at 24 kV were delivered to that same kidney. Four hours after the end of shock wave lithotripsy (SWL) the kidneys were perfusion fixed and then processed to quantitate the size of the parenchymal lesion. RESULTS: Pigs (n¼6) treated using a pause-less protocol including 300 low-energy priming dose SWs had a lesion measuring 0.770.55% FRV (mean SE). This lesion is smaller (and approaching significance) than the lesion size of 3.311.06% FRV seen when giving a clinical dose of 2000 SWs at 24 kV. CONCLUSIONS: While these data are preliminary, they indicate that treatment using a pause-less protocol including 300 lowenergy priming dose SWs shows promise as a protocol that provides both injury protection and a short treatment length. This information can be used to help formulate a practical SWL treatment protocol that can insure patient safety and can be easily adopted in the urology clinic. Source of Funding: NIH grant PO1 DK43881
MP20-19 SHOCKWAVE LITHOTRIPSY WITH RENOPROTECTIVE PAUSE IS ASSOCIATED WITH RENOVASCULAR VASOCONSTRICTION IN HUMANS Franklin Lee*, Ryan Hsi, Mathew Sorensen, Marla Paun, Seattle, WA; Barbrina Dunmire, Seattle, WA; Ziyue Liu, Bloomington, IN; Michael Bailey, Jonathan Harper, Seattle, WA INTRODUCTION AND OBJECTIVES: During shockwave lithotripsy (SWL), pre-treatment with low-energy shocks followed by a 3minute pause mitigates renal injury in an animal model. In the same model, the pause is associated with an increase in resistive index (RI), suggesting that renal vasoconstriction leads to protection from kidney injury. The purpose of our study was to investigate whether this association is observed in humans. METHODS: Patients were prospectively recruited from two hospitals. All underwent SWL of renal stones with a Dornier Compact S lithotripter at 1 Hz and received an initial 250 shocks at the lowest power setting followed by a 2 minute pause. Treatment power was then ramped up after the pause while maintaining the 1 Hz shock frequency with the total shocks delivered at the discretion of the operating surgeon. RIs were measured using ultrasound at baseline after induction, during the pause at 250 shocks, after 750 shocks, 1500 shocks, and at the end of the procedure. A linear mixed-effects model was used to compare RI at the different timepoints and to account for additional covariates including age, gender, laterality, and body mass index (BMI).
e203
RESULTS: 15 patients (4 female, 11 male) were enrolled with mean age of 61 15 years and average BMI of 29 5 kg/m2. Average stone size was 10.4 7.7 mm with average treatment time of 45 9.7 minutes. Average RI pretreatment, after 250 shocks, 750 shocks, 1500 shocks, and post-treatment were 0.680.06, 0.710.07, 0.730.06, 0.750.07 and 0.750.06, respectively. RI was found to be significantly higher post-treatment compared to pre-treatment (p<0.001) with a significant rise starting after 250 shocks (p¼0.04). After 750 shocks, the RI stabilized and did not increase further (p¼0.17). Age, gender, BMI, and treatment side, did not significantly affect RI. CONCLUSIONS: The SWL protocol with a renoprotective pause is associated with a rise in RI in humans occurring around 250 shocks into treatment. This suggests that allowing 4 to 5 minutes for renovascular vasoconstriction to develop may be beneficial. Monitoring for a rise in RI during SWL is possible and may provide real-time feedback as to when the kidney is protected. Source of Funding: NIH DK43881 and DK092197, and NSBRI through NASA NCC 9-58.
MP20-20 C-REACTIVE PROTEIN: IS IT THE END OF UNMERITED MEDICAL EXPULSIVE THERAPY? Altaf Khan*, Manjunath Shetty, Mangalore, India INTRODUCTION AND OBJECTIVES: C-Reactive Protein (CRP) is an acute phase reactant protein which is elevated in infections such as pyelonephritis. It was first used by the authors as marker of expulsive rate of single small (5-7mm) lower ureteric calculi. This is the continuation of the same study with inclusion of total white cell count and ESR and their association with the expulsive rate of small ureteric calculi. METHODS: A total of 500 patients with 5-7mm lower ureteric calculi with mild symptoms were included in the study during the period from Nov 2009-Oct 2013. All patients were investigated according to strict investigation protocol which included total count, ESR, CRP, S. Creat and NCCT abdomen and pelvis. Patients were subjected for medical treatment with alpha blockers (tamsulosin 0.4mg in patients >40yrs and alfuzosin 10mg in <40 yrs age group), diuretics and analgesics whenever required. Of the 500 patients, 239 had a CRP of <20, 157 had between 21-40 and 104 had CRP >40mg/L. Average stone size was comparable for all groups. RESULTS: Patients were followed up after 3 weeks of medical treatment. Patients were assessed for symptom relief, investigated with NCCT abdomen and pelvis. Of the 239 patients with CRP <20mg/L 202 (84.51%) had passed the stone on follow up. Of 157 patients with CRP between 20-40, 69(43.94%) had passed the stone. But of 104 patients with CRP >40 only 11(10.57%) had passed the stone. Patients with non expulsion of stone were subjected for Ureterorenoscopy and intracorporeal lithotripsy. It was found that there was no correlation between total wbc count and also ESR with expulsion rate of lower ureteric calculi. CONCLUSIONS: If we are racing towards evidence based urology then here we have a marker which may probably help us do away with un necessary medical expulsive therapy by predicting spontaneous passage rate of small lower ureteric calculi. Medical expulsive therapy can be discarded if the CRP is on the higher side. Source of Funding: none