Due to many vascular branches on the supra-hepatic vena cava (SHVC) and infra-hepatic vena cava (IHVC), in the whole procedures of preparation of liver donation, preparation of hepatic vena cava (HVC) is the most key and troublesome step. Magnetic Spiderman (MS) is a novel surgical instrument, designed and created to solve the vital problems of preparation of liver donation's HVC. Therefore, the aim of this study is to evaluate the feasibility and security of MS when using it prepare the liver donation's HVC.

From January 1 2020 to June 30 2020, after inclusion and exclusion, donors' livers will be divided to MS group and manual (MA) group. In MS group, MS grips the SHVC and IHVC, respectively. MS's magnets are adsorbed on the wall of the basin and MS can pull the HVC accordingly. By changing the position of MS on the wall of the basin, the attending can expose the surgical field that make the operation convenient. In MA group, assistants use vessel forceps to pull the HVC according to the attending's requirements. In both groups, right adrenal vein, phrenic veins and other branches of the HVC are isolated and ligated, then SHVC and IHVC where MS's clamps gripped are cut off. After preparation, the SHVC and IHVC remain at least 1.5 cm. Excess diaphragms are removed. Outcomes of two groups are compared.

Inclusion Criteria:

• all patients receiving donation after cardiac death in the First Affiliated Hospital, School of Medicine, Xi'an Jiaotong University.

Exclusion Criteria:

• patients whose age<18, or >60
• patients who do not have intact clinical data
• patients who are inability to participate in follow-up
• patients who undergo split liver transplantation