Abstract: Objective To explore the left colic artery（LCA）during laparoscopic radical resection of rectal cancer Efficacy and risk factors of postoperative anastomotic leakage in patients with inferior mesenteric artery（IMA）type 3 rectal cancer.Methods 102 patients with IMA3 rectal cancer were divided into the study group（52 cases）and the control group（50 cases）according to different surgical treatment methods.The study group was treated with LCA in laparoscopic radical resection of rectal cancer，while the control group was treated with LCA without laparoscopic radical resection of rectal cancer，and the clinical efficacy of the two groups was compared.Results The operation time of the study group and the control group were（149.2±25.）minutes and（145.8±22.5）minutes，and the hospitalization time was（11.8±2.4）days and（12.2±2.8）days，respectively.The number of lymph node dissections was（14.6±2.5）The sum of（14.8±2.6）pieces of IMA root lymph node dissection was（3.2±1.3）and（3.0±1.5），respectively.The 1-year overall survival rate was 88.1% and 83.3%，respectively.The recurrence or metastasis rate were respectively.For 14.3% and 11.9%，there was no significant difference between the two groups（P>0.05），and the anal exhaust time was（35.6±5.4）hours and（45.3±8.6）hours，respectively.The incidence of postoperative anastomotic leakage was 1.9% and 14.0%，respectively.The difference between the two groups was statistically significant（P<0.05）.The incidence of intestinal obstruction，urinary retention and urinary tract infection were 9.6% and 12.0%，1.9% and 4.0%，5.8% and 8.0%，respectively.Preoperative life quality was（56.2±9.2）and（56.5±10.5），and postoperative life quality was（78.8±12.2）and（78.4±12.0），respectively，with no statistically significant difference between the two groups（P>0.05）.Conclusions〖WTBZ〗〓In the case of clinical safety and efficacy，the retention of LCA in laparoscopic radical resection of the rectum can effectively reduce the incidence of postoperative anastomotic leakage in patients with IMA3.Therefore，in the future clinical work，these patients should be paid attention to.

Key words: Laparoscopic, radical resection of rectal cancer, inferior mesenteric artery, left colic artery, anastomotic leakage, influencing factors