Introduction: Redo pyeloplasty can be difficult due to scar tissue or fibrosis. Ureteral reconstruction with a buccal mucosal graft is performed safely and successfully, but most reports of ureteral reconstruction using a buccal mucosal graft are of robotassisted surgery, with few reports of laparoscopic-assisted surgery. A case of laparoscopic-assisted redo pyeloplasty using a buccal mucosal graft is presented. Case presentation: A 53-year-old woman was diagnosed with ureteropelvic junction obstruction, and a double-J stent was placed to relieve backache. She visited our hospital 6 months after double-J stent placement. Three months later, laparoscopic pyeloplasty was performed. At 2 months postoperatively, anatomic stenosis occurred. Holmium laser endoureterotomy and balloon dilation were performed; however, the anatomic stenosis recurred, and laparoscopic redo pyeloplasty with a buccal mucosal graft was performed. After redo pyeloplasty, obstruction was improved, and her symptoms disappeared. Conclusion: This is the first case of using a buccal mucosal graft for laparoscopic pyeloplasty in Japan.

Background/Aim: We evaluated the efficacy and safety of tolvaptan for autosomal dominant polycystic kidney disease (ADPKD) in real-world practice. Patients and Methods: We retrospectively reviewed the cases of 27 patients who had been diagnosed with ADPKD between January 2014 and December 2022. Among them, 14 patients received tolvaptan (60 mg/day; morning: 45 mg, night: 15 mg) after being admitted for 2 days. In the outpatient clinic, blood and urine samples were taken monthly. Results: The mean age, pretreatment estimated glomerular filtration rate (eGFR), treatment duration, and total kidney volume were 60 years, 45.6 ml/min/1.73 m2, 2.8 years, and 2,390 ml, respectively. One month later, the patients' renal dysfunction had worsened slightly, and their serum sodium concentrations had significantly increased. After one year, the mean reduction in the eGFR was -5.5 ml/min/1.73 m 2 . Moreover, at 3 years the patients' renal function was stable. No hepatic dysfunction or electrolyte abnormalities were noted, although discontinuation occurred in two cases. Tolvaptan treatment is considered to be safe. Conclusion: Tolvaptan was effective against ADPKD in a real-world setting. Moreover, the safety of tolvaptan was confirmed.