Introduction
The changes experienced by the therapeutic method of HCC remain unprecedented over the past decade. LLR has become the main treatment for HCC since it first reported in 1991 with the development of endoscopic technology. Although the therapic technology of HCC has been improved continuously, its mortality is still high. Metastasis is the major lethal factor for postoperative patients of HCC. For metastasis, extrahepatic metastasis takes up 14.0-25.5%[1].The lung is the second common metastasis organ after LLR and OLR[2], meanwhile, the PM is accounting for 30-50% of extrahepatic metastasis cases [3, 4].And it is difficult to detect PM early, other than regular imageological examination. Therefore, pulmonary metastasis impacts the postoperative survival rate of HCC[2]. Through clinical comparison, there were more patients with pulmonary metastasis after LLR than OLR. The purpose of this study was to explore the effect factors of LLR and OLR for postoperative pulmonary metastasis.