Thymic tumors are uncommon, constituting about 20 percent of the cases with mediastinal masses; however, they are seen more often in China. Complete resection of the tumor is the best treatment for those without invasion and resection followed by radiotherapy or chemotherapy are for those with invasion or metastasis. The five-year survival rate of thymoma is 85 percent in those patients without invasion and 50 percent in those with invasive tumor.

Patients with superior vena caval obstruction and superior vena caval syndrome may be treated with surgery, radio­therapy and/or chemotherapy. Surgical intervention with vascular reconstruction included methods using autograft, venous homograft, or artificial graft. Venous replacement with autograft gave the best result but it is not always feasible to obtain a large, expandable autogenous vein for use. The use of the venous hemograft would obviate the problem of graft availability, but the late patency rate for such grafts is only 10 to 37 percent. The common causes of occlusion of such venous grafts are intimal thickening, disruption of the media, and perivascular fibrosis due to its antigenicity. Synthetic grafts thrombose easily because of their surface properties. Gore-Tex is possibly an exception and has been used for innominate vein replacement with success. The patency rate of Gore-Tex graft in animal studies is 83 percent and in human clinical trials, 62 percent. The survival rate of 13 patients with mediastinal-pulmonary malignant tumor who had resections of their tumor and superior vena cava followed by Gore-Tex reconstruction was 27 percent at three years. Cialis Jelly

Invasive thymoma with superior vena caval syndrome is rare. Only four cases had been reported in the English literature. Dartevelle et al reported good results in treating one patient with en bloc resection of the tumor and a segment of superior vena cava and innominate vein followed by venous reconstruction.® In the report of Mendez- Fernandez et al, thymoma invaded the left innominate vein without obstruction, and en-bloc restriction of the tumor and a segment of the innominate vein was performed followed by reconstruction of the innominate vein with a ringed Gore-Tex graft. The result at six months was satisfac­tory. In the case of Arai et al, the thymoma involved the left innominate vein causing complete occlusion. En-bloc resection of the tumor and the left innominate vein was done, followed by reconstruction of the superior vena cava and right innominate vein with autogenous venous graft. Postoperative radiotherapy was not given, but the venous graft remained patent, lanabe et al reported the long-term follow-up of one patient with thymoma who was treated with reconstruction of superior vena cava and Teflon patch angioplasty; the graft remained patent for more than ten years. These gratifying results in the literature and of our own experience seemed to justify the notion that invasive thymoma with superior vena caval obstruction should be treated aggressively.