Introduction: Parametrial endometriosis could often involve the ureter and periureteral tissue causing hydronephrosis and distortion of the normal ureteral course and position. The treatment in the case of hydronephrosis could be ureterolysis (with or without the positioning of a stent) or a ureteral resection. Materials and methods: This is the case of left parametrial endometriosis with hydronephrosis in a young woman. The preoperative work-up showed a deep infiltrating endometriosis of the left parametria, the left uterosacral ligament, and the left ureter which caused hydronephrosis. The patient was symptomatic (dysmenorrhea, dysuria, and pelvic pain). In this video, we focused on ureterolysis: all the endometriotic tissues were removed, the ureter was completely released, and the decision was to place a stent in the ureter without ureteral resection. Results: The post-operative course was normal, the stent was changed after 1 week (from mono-J to double-J) and removed 1 month after surgery. Follow-up at 3 and 8 months after stent removal was normal, and renal function was normal. The last follow-up, after 13 months, showed no hydronephrosis, no signs of deep infiltrating endometriosis, and normal renal function. The patient continues with oral contraception. Conclusion: Ureterolysis could be an effective alternative to ureteral resection in cases of deep infiltrating endometriosis even when the ureter is involved with hydronephrosis.
