Flexible ureteroscopy with ultrasound guidance for the treatment of parapelvic renal cysts: A complementary approach for locating the cystic wall

BACKGROUND: Flexible ureteroscopic incision and drainage is a relatively new surgical method for treating parapelvic cysts. Considering that the intraoperative localization of the cyst may fail with a flexible ureteroscope, we use an innovative ultrasound-guided method to locate the cystic wall during flexible ureteroscopic surgery. METHODS: We retrospectively reviewed 17 consecutive cases of parapelvic renal cysts treated by ultrasound-guided flexible ureteroscopy between March 2017 and May 2020. The differences between the simple flexible ureteroscopic technique and ultrasound-guided flexible ureteroscopic technique were compared. The surgical procedures, postoperative complications, results and patient follow-ups were evaluated. RESULTS: The cyst wall was seen clearly in 10 patients with ureteroscopic vision. Another 7 patients underwent ultrasound-guided flexible ureteroscopic surgery since it was difficult to identify the cyst wall. The mean operative time was 25.9 ± 8.7 min and 37.1 ± 10.1 min for the conventional and modified techniques, respectively (P = 0.004); the mean time to search for cysts was 17.6 ± 5.8 min and 26.5 ± 8.4 min, respectively (P = 0.002); and the mean incision time was 7.1 ± 4.9 min and 12.1 ± 5.6 min, respectively (P = 0.000). All of the patients were followed-up for 12 months, and no serious complications or recurrence were observed. CONCLUSIONS: We demonstrated that it is feasible and safe to treat parapelvic renal cysts by ultrasound-guided flexible ureteroscopic incision and drainage. The small sample size and need for further studies were the limitations of our work. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12894-022-00960-6.