Improvement in Renal Function and Symptoms of Patients Treated with Laparoscopic Pyeloplasty for Ureteropelvic Junction Obstruction with Less Than 20% Split Renal Function

Introduction: To evaluate the efficacy of laparoscopic pyeloplasty (LPP) for lower functioning kidney, we investigated the outcome of this procedure for patients with ureteropelvic junction obstruction with decreased renal function, defined as less than 20% split renal function. Patients and Methods: Between October 1998 and June 2015, we performed transperitoneal dismembered LPP in 224 patients. Among them, 15 patients with less than 20% split renal function were included in this study. Patient characteristics, perioperative split renal functions, complications, and surgical outcomes were retrospectively investigated. Results: Fourteen of 15 patients had preoperative symptoms, including flank pain in 13 patients and gross hematuria in 1 patient. Preoperative 99mTc-mercaptoacetyltriglycine (MAG3) renogram revealed no response to diuretic injection and median split renal function was 16.5%. Median operative time and blood loss were 170 minutes and 20 mL, respectively. There were no complications during the perioperative period. Postoperative MAG3 renogram at 6 and 12 months after the operation revealed significantly increased split renal function (median: 23.8% and 23.7%, p = 0.001 and 0.008, respectively) and response to diuretic injection in all patients. Preoperative symptoms disappeared and no recurrence was seen during the follow-up period for all patients except for one who experienced flank pain again 4 months after the surgery. He subsequently underwent open pyeloplasty, and flank pain disappeared soon after. Conclusions: LPP for patients with low split renal function and flank pain significantly improved symptoms and split renal functions. Although the long-term clinical effects of LPP are unknown, we recommend performing LPP before considering nephrectomy for patients with lower functioning kidney.