Abstract: Objective： To summarize the experience of flexible ureteroscopic holmium laser resection in treatment of renal pelvic carcinoma and to evaluate its value in treatment of renal pelvic carcinoma. Methods: The clinical data of 6 patients with renal pelvic carcinoma treated in Peking University Third Hospital from January 2015 to January 2017 were retrospectively analyzed. The 6 patients were treated by the same experienced urologist and by flexible ureteroscopic holmium laser resection of renal pelvic tumors under general anesthesia. Regarding the intensity of the holmium laser, 10-30 W was generally used with settings of 0.5-1.5 J and 10-20 Hz. In general, a 200 μm end-firing holmium laser fiber was used. Narrow-band imaging (NBI) technique was applicated to search for tumors and check whether the excision was satisfactory. Routine “second flexible ureteroscopy” was performed after 4-6 weeks, and suspected lesions were referred for a biopy, then vaporized and cauterized. The ureteroscopy was examined every 6 months after operation, and color Doppler ultrasound, computed tomography urography (CTU) or magnetic resonance urography (MRU) were performed at the same time. The urine tumor cells were examined for 3 days before the operation, and the urine tumor markers, such as urinary nuclear matrix protein 22 (NMP22) were tested. For cases with high-risk urothelial carcinoma and normal renal function, and 6 cycles of systemic adjuvant chemotherapy were performed after operation. Results: All of the cases were successfully treated. The data were as follows: the operation time 77.5 min (45-115 min), the blood loss 10 mL (5-20 mL), and hospital stay after surgery 3 days (2-5 days). After 13-34 months’ follow-up, two patients had recurrent tumor recurrence and underwent resection operation. Two patients received systemic adjuvant chemotherapy after operation. Case 5 was histopathologically high grade urothelial carcinoma, and 6 cycles of systemic chemotherapy were given after operation. Local recurrence occurred during chemotherapy, and then endoscopic operation was performed, and no recurrence occurred in the follow-up for 12 months after reoperation. In case 6, the pathology was low grade urothelial carcinoma, but the case was multiple tumors in the right renal calyx and the lower calyx. Then 6 cycles of systemic chemotherapy were given, and no recurrence was found in the follow-up for 13 months. Conclusion: Transurethral flexible ureteroscopic holmium laser resection is relatively safe for the treatment of renal pelvic carcinoma. It is suitable for special cases of solitary kidney and renal dysfunction, as well as for patients with low risk urinary tract epithelial tumors, but the recurrence rate is high, and the indications need to be strictly controlled. Patients with high-risk urothelial carcinoma who underwent endoscopic resection are advised to receive systemic adjuvant gemcitabine and cisplatin (GC) regimen after surgery, in order to increase the overall survival rate. Systemic chemotherapy combined with endoscopic operation may become a new treatment for upper tract urothelial carcinoma (UTUC).

Key words: Ureteroscopy, Holmium laser, Renal pelvic carcinoma