[Research progress on early diagnosis and prevention of anastomotic leak after rectal cancer surgery].

Anastomotic leak is a common and serious complication after anterior rectal resection. Despite the continuous advancement of anastomotic instruments and surgical techniques, the incidence of anastomotic leak has not decreased significantly compared with the past. As more studies on the early diagnosis of anastomotic leak are published, postoperative risk factors of anastomotic leak, such as fever, time to first bowel movement, CT, C-reactive protein (CRP) and procalcitonin (PCT), matrix metalloproteinase-9, and other cytokines and biomarkers (IL-6, TNF-α, lactate, pH, urinary neopterin/creatinine ratio), provide a reference for surgeons to assess the risk and increase the possibility of early diagnosis of anastomotic leak. Nevertheless, preventing the occurrence of anastomotic leak is still the ultimate goal. For the prevention of anastomotic leak, intraoperative ICG fluorescence imaging technology provides a simple and safe objective method for surgeons to evaluate anastomotic perfusion. The diversion stoma may reduce the incidence of anastomotic leak. More and more evidence shows that drainage through the anal canal can reduce the incidence of anastomotic leak after rectal cancer, but whether different types of drainage catheters can clearly reduce the incidence of anastomotic leak still needs more evidence. In addition, there has not yet been a unified opinion on the retention time and location of the drainage catheter. At present, the research of anastomotic leak has not adopted a unified definition and the heterogeneity among related studies is still great. We still look forward to more high-quality multi-center large prospective and randomized controlled studies.