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).
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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