[Problem of the carbon dioxide embolism during the procedure of transanal total mesorectal excision]

Carbon dioxide embolization is a special complication of laparoscopic colorectal surgery. It is rarely reported in conventional laparoscopic colorectal surgery, and has not been well recognized by surgeons. Transanal total mesorectal excision (taTME) is an increasingly popular sphincter-preserving surgery for low rectal cancer in recent years. Although the number of cases worldwide is not large, carbon dioxide embolization after operation has been reported successively. Once serious carbon dioxide embolization occurs, the mortality is extremely high. The main related factors of carbon dioxide embolization in taTME include high pressure of pneumoperitoneum, narrow space, abundant blood supply of prostate and vaginal wall, Trendelenburg position, etc. The key of prevention and treatment is to pay attention to the control of related risk factors, identify the early signs of carbon dioxide embolism, and take active and effective symptomatic treatment. Reducing the pressure of pneumoperitoneum perfusion can reduce the occurrence of CO2 embolism. Transesophageal echocardiography is the most sensitive way to monitor intravenously CO2, but it is difficult to carry out in clinical practice. The sudden decrease of end expiratory CO2 partial pressure is an important sign of early detection of CO2 embolism. If there is a suspicious lacuna in the operation, it is possible to reduce or stop the pneumoperitoneum when it is unable to distinguish between normal tissue gap or vascular lumen. If the "bubble sign" is observed, CO2 may enter the vein. The risk of venous embolism should be considered.