Introduction: For left side colon cancer surgery, the roots of the inferior mesenteric artery and vein (IMA/IMV) are generally cut to perform the D3 lymph node dissection. In these cases, the extended resection of the colon would be required owing to the poor blood supply of the colon. In order to reduce the risk of distal bowel ischaemia and anastomosis leakage and preserve more normal sigmoid colon function, we aimed to introduce an innovative method to preserve the IMA/IMV and present its efficacy and safety. Materials and Methods: From January to February in 2019, two advanced colonic splenic flexure cancer (CSFC) patients received total laparoscopic left hemicolectomy with preservation of IMA/IMV combined with natural orifice specimen extraction surgery. The surgery followed the D3 lymph node dissection principle. Results: Two patients underwent a total laparoscopic surgery and no cases were converted to open or laparoscopic-assisted surgery. The mean time of operation was 148 min and mean blood loss was 50 ml. The harvested lymph nodes were 17 and 39 respective and the length of normal bowel both proximal and distal to the tumor more than 10 cm. The mean time of post-operative hospitalisation was 6 days. There were no cases of intra-or post-operative morbidity, or of bleeding owing to vessel injury. Conclusion: It is an efficient and safe technique to treat CSFC in a setting of surgeons experienced in laparoscopic colorectal surgery.