Objective: Surgical treatment of complex mediastinal tumors is still a challenging common problem, summarizing the authors from October 2002 to October 20013, a total of 12 patients with complex mediastinal tumors were admitted and discharged with good results after surgical cure, the preliminary experience is reported as follows. Clinical data: In this group, there were 12 cases, 7 males and 5 females; age 14-81 years old, average 43 years old; 11 cases of anterior mediastinal tumors (5 cases of malignant thymus stay, 3 cases of thymic carcinoma, 2 cases of teratoma combined with thymic cyst, 1 case of metastatic anterior mediastinal tumor after breast cancer surgery; 5 cases of severe superior vena cava syndrome combined before surgery.) The preoperative CT and MRI examinations suggested complete obstruction of the superior vena cava in 3 cases and suspected partial obstruction in 2 cases. Surgical methods: general anesthesia, median sternotomy into the chest, resection of tumor with bilateral innominate vein and superior vena cava + artificial vessel graft in 5 cases; resection of tumor + superior vena cava angioplasty in 2 cases; resection of tumor + innominate vein angioplasty in 2 cases; repair of main pulmonary artery of thoracic adenocarcinoma under extracorporeal circulation and parallel circulation in 1 case; there was another case of huge isolated fibroma weighing 4 kg, which could not be removed after freeing the whole piece, so it was cut into four pieces and removed. In another case, a huge isolated fibrous tumor weighing 4 kg could not be removed in its entirety after freeing, and was removed in four pieces. In one case, the tumor involved the chest wall, and after resection of the whole piece, chest wall reconstruction was performed with a porous titanium plate. The artificial blood vessel graft was given anticoagulation therapy with Warfarin after the drainage tube was removed after surgery, while no special anticoagulation therapy was used for angioplasty. Results All 12 patients in this group were discharged with no operative mortality and no serious complications. Postoperative ultrasound examination of superior vena cava blood flow was usually free of obstruction, and postoperative follow-up ranged from 9 months to 141 months, with a mean follow-up of 47 months; one patient with malignant thymoma died of respiratory failure complicated by myasthenia gravis 5 months after surgery, while the rest of the patients survived in good health. 1. Accurate determination of whether the tumor invades the superior vena cava and its branches and the extent of invasion before surgery is very important for the formulation of the correct surgical plan. For patients with anterior superior mediastinum tumor, preoperative CT, MRI or angiography should be used to determine whether the superior vena cava and its branches are invaded or not. For patients with large tumor and close relationship with the above mentioned vessels, even if there is no sufficient evidence of vascular invasion, preoperative artificial vessels of different caliber should be prepared in case of emergency. 2.For patients without distant metastasis, if the tumor only invades the superior vena cava and its branch vessels, the tumor should be removed together with the involved vessels and treated with artificial vessel graft or angioplasty at the same time, which can achieve good results. For patients with small tumor involvement, the authors use to free the tumor surrounding area first and deal with the vascular involvement last. The advantage is that after the tumor is removed, it is easy to reveal the operation field and facilitate the operation of angioplasty. There are various methods of angioplasty for superior vena cava and its branches, but the general principle is to determine the scope of vascular resection and the method of angioplasty according to the extent of tumor invasion. The general principle is to determine the scope of vascular resection and the method of angioplasty according to the extent of tumor invasion and to simplify the operation as much as possible. For those whose invasion of superior vena cava is less than 1/3 circumference and often less than 2 cm in length, the superior vena cava is partially blocked by heart auricular clamp, wedge-shaped resection of the involved vessels, and direct transverse continuous suture with 6/0 Prolene thread; while for those whose tumor has seriously invaded superior vena cava or unnamed vein, resulting in venous return obstruction, artificial vessel graft is necessary to completely resect the tumor. 4. For huge tumor resection, it is necessary to consider not only the surgical field exposure, but also the compression of heart and lung by tumor, which may cause cardiopulmonary insufficiency and endanger life. Therefore, the surgical position should be patient safety first and the compression should be lifted as soon as possible during operation. Cystic tumor can be considered to be incised first and some of the cystic fluid can be sucked out to decompress; if it is a solid tumor, it is difficult to be removed quickly, it should be incised in time and removed in pieces for safety.