Feasibility of the "One-Finger Technique" for Identifying the Upper Left Ureter During Para-Aortic Lymphadenectomy

Inclusion Criteria: * Females aged 18-75 years; * Diagnosed with gynecological malignancies (e.g., cervical cancer, endometrial cancer, ovarian cancer) confirmed by histopathology or cytology; * Planned to receive open surgical treatment and have surgical indications for para-aortic lymphadenectomy according to guidelines; * ECOG performance status score: 0\~1; * Fully understand the purpose, nature, methods, and potential risks and benefits of this study, voluntarily participate in this study, and sign a written informed consent form. Exclusion Criteria: * Concurrently have malignant tumors in other systems; * Previous history of left kidney or ureter surgery, or known severe anatomical variations of the urinary system (such as duplex kidney, duplex ureter, pelvic ectopic kidney, etc.); * Severe intestinal adhesions caused by previous abdominal surgery for other reasons; * Previous history of pelvic/abdominal radiotherapy, or severe adhesions and unclear anatomical structures in the retroperitoneal space due to previous abdominal surgery or severe pelvic/abdominal infection; * Preoperative imaging (CT/MRI) indicates massive confluent lymph nodes in the retroperitoneum, or lymph nodes that have encased major blood vessels such as the left ureter, abdominal aorta, and inferior vena cava, where routine space dissection is expected to be impossible; * Presence of absolute contraindications for open surgery, such as severe cardiac, hepatic, or renal insufficiency, or coagulopathy; * Other conditions deemed unsuitable for enrollment by the investigator.