Subxiphoid VATS for Giant Mediastinal Teratoma

Inclusion Criteria: * Age: 10 - 70 years old, gender unrestricted; Preoperative enhanced CT or MRI confirms anterior mediastinal mass with the maximum diameter ≥ 7 cm; Intraoperative frozen section pathology confirms teratoma (mature or immature type); American Society of Anesthesiologists (ASA) classification grade I - III, with acceptable cardiopulmonary function for single-lung ventilation; No severe thoracic deformity or severe adhesion in the posterior mediastinum (assessed by preoperative imaging); Patients voluntarily sign the informed consent form, understanding the purpose and potential risks of the study. Exclusion Criteria: * Tumors invading major blood vessels (such as the innominate vein, superior vena cava, or aorta) or the pericardium require combined vascular/pericardial resection and reconstruction; Tumors crossing the midline and encasing the trachea or esophagus require multidisciplinary joint surgery; Previous mediastinal surgery or radiotherapy history, leading to local anatomical structure disorder; Coagulation dysfunction (INR \> 1.5 or platelet count \< 50×10⁹/L); Severe immune deficiency (such as HIV infection, long-term glucocorticoid treatment); Pregnant or lactating women; Concurrent other malignant tumors (metastatic lesions need to be excluded); Severe cardiopulmonary diseases (such as COPD GOLD Ⅲ-Ⅳ grade, NYHA cardiac function Ⅲ-Ⅳ grade); Mental illness or cognitive impairment that cannot cooperate with postoperative follow-up; Participated in other clinical trials that may interfere with the results of this study.