2306 P40 PROVIDES VALUABLE FUNCTIONAL INFORMATION BEFORE AND AFTER SURGERY FOR PROBLEMATIC UPJ OBSTRUCTION PATIENTS WITH A NORMAL PREOPERATIVE T1/2

Abstract

You have accessJournal of UrologyImaging/Radiology: Uroradiology1 Apr 20112306 P40 PROVIDES VALUABLE FUNCTIONAL INFORMATION BEFORE AND AFTER SURGERY FOR PROBLEMATIC UPJ OBSTRUCTION PATIENTS WITH A NORMAL PREOPERATIVE T1/2 Shelly X. Bian, Judy M. Choi, MD Wesley A. Mayer, MD Alvin Goh, andMD Richard E. LinkMD, PhD Shelly X. BianShelly X. Bian Houston, TX More articles by this author , Judy M. ChoiJudy M. Choi Houston, TX More articles by this author , Wesley A. MayerWesley A. Mayer Houston, TX More articles by this author , Alvin GohAlvin Goh Houston, TX More articles by this author , and Richard E. LinkRichard E. Link Houston, TX More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.2552AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Evaluating patients for UPJ obstruction involves integrating both clinical symptoms and imaging findings. Renal scanning can provide important functional information to help identify patients who would benefit from surgical correction. T1/2 (time from diuretic administration to 50% clearance of tracer) > 20 min is the gold standard for obstruction, and improvement in T1/2 after pyeloplasty indicates resolution. However, many patients present preoperatively with symptoms but a normal T1/2 (<20min) and many continue to show a delayed T1/2 despite complete resolution of symptoms postoperatively. Our goal was to explore alternative analyses of renal scans that may augment T1/2 in diagnosing clinically significant UPJO. METHODS We retrospectively reviewed records of 96 consecutive adult patients undergoing laparoscopic or robotic-assisted pyeloplasty for UPJ obstruction from 2005 to 2010 by a single surgeon. 95% were symptomatic and 5% had unilateral decreased function by imaging. Pre and postoperative MAG3 lasix-washout renal scan images were available for review in 22 patients with primary unilateral UPJ obstruction and two kidneys. We assessed five parameters: differential renal function (DRF), time from diuretic administration to 50% clearance (T1/2), time from maximum tracer uptake to 50% clearance (M1/2), percent clearance at 20 minutes (P20) and percent clearance at 40 minutes (P40). The contralateral kidney served as a control and a paired T-test was used for analysis. RESULTS Preoperatively, 10 patients (46%) had a T1/2 > 20 min, 6 > 10 min (27%) and 6 < 10 min (27%). Three measures were significantly different between the affected and control kidney: T1/2, P20, and P40. In the affected kidney with a preoperative T1/2 > 20 min, both T1/2 and P40 decreased significantly after surgery. In the problematic subset of 12 patients with a “normal” preoperative T1/2 (<20min), P40 was still significantly different between the affected and control kidney (24% v. 9%, p=0.002) and decreased significantly before and after corrective pyeloplasty (24% to 16%, p=0.036). DRF did not show significant improvement postoperatively (p>0.05) and all parameters for the unaffected kidney did not show significant change before and after pyeloplasty (p>0.05) as expected. CONCLUSIONS P40 appears to be a useful alternative renal scan marker for assessing UPJ obstruction. Even in the problematic patient with symptoms but a normal preoperative T1/2, P40 provided valuable functional information both before and after surgical correction. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e924-e925 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Shelly X. Bian Houston, TX More articles by this author Judy M. Choi Houston, TX More articles by this author Wesley A. Mayer Houston, TX More articles by this author Alvin Goh Houston, TX More articles by this author Richard E. Link Houston, TX More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...