Methods: The patients who got rectal carcinoma are divided into two groups. Both groups will receive the radical resection of rectal carcinoma. We preserve the left colic artery and resect the No. 253 lymph node specifically in Group A and divide at the root of the inferior mesenteric artery in Group B, We insert a trocar into the arterial arcade at the proximal site of the anastomosis and measure the blood pressure of the arterial arcade in the operation, which can reflect the blood supply of the anastomosis. Besides, We will measure the length of the colon from the anastomosis to the level of the root of the IMA. Expecting Results：The blood pressure of the arterial arcade in Group A will be higher than that in Group B. And the patients in Group A will have less chance to get anastomotic fistula. Expecting Conclusions: Preserving the LCA and resecting the No. 253 lymph node specifically in the radical resection of rectal carcinoma can improve the blood supply of the anastomosis and decrease the incidence of anastomotic fistula, and won't affect the harvest of the No. 253 lymph node.
To evaluate the influence to the blood supply of the anastomosis and the harvest of the No. 253 lymph nodes in different surgical methods--- preserving the left colic artery (LCA) and resect the No. 253 lymph node specifically in the radical resection of rectal carcinoma or dividing at the root of the inferior mesenteric artery (IMA) in the radical resection of rectal carcinoma.