Abstract: Department of Gastrointestinal Surgery， the Affiliated Shanghai Shuguang Hospital of Shanghai University of Traditional Chinese MedicineObjectiveTo compare the application effect of right laparoscope site versus central laparoscope site on clearing peripheral lymph node of inferior mesenteric arterial root in laparoscopic radical resection of rectal cancer. 
MethodsThe clinical data of 25 patients underwent laparoscopic radical resection of rectal cancer between January 2017 and May 2017 at the Affiliated Shanghai Shuguang Hospital of Shanghai University of Traditional Chinese Medicine were analyzed retrospectively. The right laparoscope site （laparoscope inserted through the right superior trocar） and central laparoscope site（laparoscope inserted through the superior umbilical trocar） were applied respectively when the peripheral lymph nodes of inferior mesenteric arterial root were dissected. There were 13 cases in the right laparoscope site group and 12 cases in the central laparoscope site group. The exposure effect of surgical field， the operation time， the time from the first incision on the mesentery to accomplish the D3 lymph node dissection， the blood loss， the number of dissected lymph nodes， the conversion rate， the postoperative hospital stay and the early postoperative complications were compared between both groups. All the operations were performed by the same surgical team. 
ResultsThe right laparoscope site was easier to expose the inferior mesenteric artery and nerve. There was no conversion. The mean time from the first incision on the mesentery to accomplish the D3 lymph node dissection were （280±59）min and（331±61）min for the right laparoscope site group and the central laparoscope site group， and there was statistically significant difference（P=0045）. The mean operation time were （1403±167）min and （1464±169）min， the mean blood loss were （596±176）ml and （633±144）ml， the mean numbers of dissected lymph nodes were 184±38 and 162±31， the postoperative hospital stay were （82±22） days and （83±21）days， and the early postoperative complication rates were 77％（1/13） and 167％（2/12）， with no statistically significant differences between both groups（P＞005）. 
ConclusionThe right laparoscope site has advantages for exposure of surgical field， lymph node dissection of inferior mesenteric arterial root， preservation of branches of inferior mesenteric artery and protection of inferior mesenteric nerve plexus.

Key words: Laparoscope')">">Laparoscope, Rectal cancer, Inferior mesenteric artery, Lymph node dissection