Right colon has complicated anatomy which is surrounded by important organs. The variations of vessels are more frequent than in left colon, which contribute to the difficulty of surgery. Among the variations, Henle's trunk is more obvious that makes it the commonest cause of bleeding during operation. Several veins can be found to conjoin the Henle's trunk, among which ASPDV and REGV are the two common tributaries while RCV,MCV,SRCV may vary from people to people. As a result, a better understanding of the anatomical classification of Henle's trunk is a must during operation. However, existing studies of Henle's trunk are very rare and often single-centered with minimal samples.In order to achieve better surgical outcome and reduce operative complications, the investigators design this study to investigate the anatomical classification of Henle's trunk and the surgical outcome of each type.

Inclusion Criteria:

1. Patients who undergoing laparoscopic right hemi-colectomy with D3 lymphadenectomy
2. Pathology: adenocarcinoma or high-grade intraepithelial neoplasia proven by colonoscopic biopsy.
3. Localization: tumor located between cecum and proximal 1/3 portion of transverse colon.
4. Patients have to be aware of the aim of the trial, and have signed the informed consent.

Exclusion Criteria:

1. History of any gastrointestinal surgery.
2. Patients with ileus, perforation, bleeding and any other conditions required of emergent surgery.

This study is a prospective study，and based on the number of branches, the anticipant populations of this study is 500.