163 Archivio Italiano di Urologia e Andrologia 2018; 90, 3 ORIGINAL PAPER Role of the gonadal vessels on the stone lodgment in the proximal ureter: Direct observation during laparoscopic ureterolithotomy Mohammad Hadi Radfar 1 , Reza Valipour 2 , Behzad Narouie 3 , Mehdi Sotoudeh 1 , Hamid Pakmanesh 4 1 Department of Urology, Shahid Labbafinejad Medical Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran; 2 Department of Urology, Tehran Medical Sciences Branch, Islamic Azad University, Tehran, Iran; 3 Department of Urology, Zahedan University of Medical Sciences, Zahedan, Iran; 4 Department of Urology, Shahid Bahonar Hospital, Kerman University of Medical Sciences (KMU), Kerman, Iran. Introduction: Previous radiological studies revealed that stones lodge more frequently in the ureterovesical junction (UVJ) as well as the proximal ureter. Factors that prevent stone passage from the proximal ureter are not well studied. Aim: To explore the site of the lodged stones in the proximal ureter with direct observation during laparoscopic ureterolithotomy. Materials and methods: Between November 2014 and February 2015, we included 26 patients including 18 men and 8 women with stones larger than 10 millimeters in the proximal ureter who were candidate for laparoscopic ureterolithotomy. We prospectively recorded the site of the lodged stones in the ureter during laparoscopic ureterolithotomy in relation with the sites of ureteral stenosis as well as the gonadal vessels. Results: Among 26 patients with ureteral stone, in 19 cases stone was found close to the gonadal vein compared with seven cases that stone was in other locations of the ureter (p = 0.02). The characteristics of patients and stones were not different in cases that the stone was close to gonadal vessels compared with other locations. Conclusions: This study showed that most of the stones lodged in the proximal ureter were in close proximity with gonadal vessels. Gonadal vessels may be an extrinsic cause of ureteral narrowing. KEY WORDS: Ureter; Urolithiasis; Laparoscopy; Pathophysiology; Gonadal vessels. Submitted 11 December 2017; Accepted 12 January 2018 Summary No conflict of interest declared. ureteral calculus revealed that stones lodge more fre- quently in two sites: UVJ and proximal ureter. UVJ is known unanimously as the narrowest part of the ureter (8); however, we have not a clear response to the question that why large stones that pass the UPJ, lodge in the prox- imal ureter. Ureteroscopy (TUL) or Shock wave lithotripsy (SWL) or are the first line treatment for more ureteral stones (9). For large stone burden or when previous options have failed, laparoscopic ureterolithotomy is a less invasive technique with excellent success rate (10). In this study, we prospectively investigated the location of the lodged stones in the proximal ureter under direct laparoscopic vision in patients who were candidate for laparoscopic ureterolithotomy. To the best of our knowledge, this is the first study that report intraoperative data of lodged ureteral stones in relation with the gonadal vessels. MATERIALS AND METHODS We prospectively evaluated patients who undergo laparo- scopic transperitoneal ureterolithotomy for upper ureteral stones. Between November 2014 and February 2015, we included 26 patients. The inclusion criteria was stones larg- er than 10 millimeters in the proximal ureter (from ureteropelvic junction to the iliac vessels) in the non- enhanced spiral abdominopelvic computed tomography scan (CT-Scan), that failed to response with Shock Wave lithotripsy (SWL). We excluded patients who had previous- ly underwent open stone surgery. A negative urine culture and normal coagulation tests was attained. The studied variables were patient demographic data including age, gender, height, weight, body mass index as well as stone characteristics including size, number and laterality and data of previous interventions. Urology and Nephrology Research Center Board of ethical approval approved the study. All procedures were in accordance with the ethi- cal standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Surgical technique After induction of the general anesthesia, we inserted a DOI: 10.4081/aiua.2018.3.163 INTRODUCTION Ureteral stone is a common presentation of the urinary tract stone disease that usually is associated with an excru- ciating pain (1). Most of urinary tract stones pass sponta- neously; however, some stones lodge in the ureter and require intervention (2, 3). Anecdotally, three constric- tions in the ureter are told to be the potential site of stone impaction including ureteropelvic junction (UPJ), the cross- ing of the ureter over iliac vessels and the ureterovesical junction (UVJ) (4). In contrast with this theory, data of clinical studies did not show increased rate of stone lodg- ment at the level of the iliac vessels (5-7). In addition, UPJ is not a frequent location for lodged stones. Actually, stud- ies that reviewed imaging of the patients with impacted