Abstract:

Obstructive colorectal cancer is a common malignant bowel obstruction.Loop colostomy or colostomy following tumor resection may be the first choice for emergency surgery.The intestinal and systemic conditions of patients undergoing emergency surgery are often poor， and patients need to undergo multiple operations， which increase the surgical risk and economic burden and reduce the quality of life of patients.Poor intraoperative visual field may also affect the radical operation of emergency surgery.Transanal decompression tube （TDT） can rapidly decompress and drain the obstructed bowel， effectively relieve obstruction symptoms， and improve the success rate of primary radical resection.The TDT squeeze the tumor lightly， causing no spread of tumor cells， and is cheap， but the cavity of transanal decompression tube is small and easily blocked， and requires tedious flushing or regular replacement.Self-expanding metallic stents （SEMS） can relieve intestinal obstruction effectively， provide sufficient preoperative preparation time，complete preoperative examination， evaluate the tumor thoroughly， improve the patient’s nutritional status，and improve the patient’s tolerance to radical surgery， which might be used as an important treatment strategy choice for obstructive colorectal cancer.However， SEMS may squeeze the tumor， leading to the spread of tumor cells， increase the recurrence rate and metastasis rate， and reduce the survival rate.Moreover， intestinal wall edema still existed during the operation following SEMS， and the rate of ostomy after anastomosis was as high as 34%.We hypothesized that prolonging the interval between stent insertion and surgery to 2 months， with neoadjuvant chemotherapy administered during this interval （SEMS-neoadjuvant chemotherapy strategy）， would help improve outcomes.The SEMS-neoadjuvant chemotherapy strategy is a safe， effective，and well tolerated treatment approach with a high laparoscopic resection rate， low stoma formation rate and improvement in the overall survival for patients with left-sided colon cancer obstruction.The patient physical status is improved， the primary tumor is downstaged， and intestinal wall edema is relieved during the relatively longer interval between SEMS placement and surgery.The SEMS-neoadjuvant chemotherapy strategy may be one of the preferred therapeutic strategy for obstructive left colon cancer.

Key words: Colorectal neoplasms, Obstructive colorectal cancer, Emergency surgery, Transanal decompression tube, Self-expanding metallic stent, Neoadjuvant chemotherapy, Prognosis