www.kjurology.org DOI:10.4111/kju.2010.51.6.434 Case Report Successful Endourologic Management of Lower Pole Moiety Ureteropelvic Junction Obstruction in a Partially Duplicated Collecting System Eugene Hwang, Young Ho Kim, Seung Woo Yang, Chang Shik Youn, Seung Mo Youk, Chong Koo Sul, Jae Sung Lim Department of Urology, Chungnam National University School of Medicine, Daejeon, Korea We present two cases of symptomatic lower pole moiety ureteropelvic junction ob- struction (UPJO) in a partially duplicated collecting system that were successfully treated with minimally invasive endourologic procedures. In the first case, we per- formed retrograde endopyelotomy with the AcuciseⓇ ureteral cutting balloon device, and in the latter case, we performed percutaneous nephrolithotomy and antegrade en- dopyelotomy because of the presence of multiple renal stones. Subsequent intravenous pyelography confirmed marked resolution of the obstruction, and both patients re- mained asymptomatic during 1 year of follow-up. Key Words: Minimally invasive surgical procedures; Nephrolithiasis This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Article History: received 25 March, 2010 accepted 28 April, 2010 Corresponding Author: Jae Sung Lim Department of Urology, Chungnam National University School of Medicine, 33, Munhwa-ro, Jung-gu, Daejeon 301-721, Korea TEL: +82-42-280-7779 FAX: +82-42-257-0966 E-mail: uro17@cnu.ac.kr Although complete or incomplete ureteral duplication is one of the most common congenital malformations of the urinary tract, ureteral duplication with concomitant lower pole ureteropelvic junction obstruction (UPJO) is unusual, and the simultaneous presence of multiple renal stones is rare. 　Until recently, the standard treatment of UPJO in a du- plex renal system was open pyeloureterostomy. However, minimally invasive endoscopic surgery is preferred in se- lected patients. We describe our experience with the suc- cessful management of UPJO in a partially duplicated col- lecting system in both a retrograde and an antegrade fashion. CASE REPORTS Case report 1 A 32-year-old man was referred with dull, aching right flank pain for 3 years. The patient was evaluated by ab- dominal computerized tomography, which revealed in- complete duplication of the right urinary system with low- er pole moiety hydronephrosis. No extraluminal crossing vessels were detected. Retrograde pyelography showed UPJO with moderate hydronephrosis of the lower pole moi- Korean Journal of Urology Ⓒ The Korean Urological Association, 2010 ety (Fig. 1). An endopyelotomy with the AcuciseⓇ (Applied Medical) ureteral cutting balloon device was planned. FIG. 1. Preoperative retrograde pyelography showing lower pole ureteropelvic junction obstruction with normal upper pole moiety. 434 Korean J Urol 2010;51:434-437