Abstract:

Objective To evaluate the efficacy and safety of external anal sphincter injection of botulinum toxin in modified Bacon surgery for low rectal cancer. Methods Clinical medical records of eligible patients with low rectal cancer admitted to our hospital from June 2016 to October 2019 were retrospectively analyzed. Among them，43 patients underwent modified Bacon combined with botulinum toxin，and 36 patients underwent modified Bacon. The operative time，intraoperative blood loss，postoperative first exhaust time，length of hospital stay， postoperative incidence of complications such as abdominal pelvic infection，respiratory tract infection，intestinal obstruction，external intestinal necrosis，anal stenosis，and postoperative LARS score and LARS grading were compared between the two groups. Results Both groups of patients completed the operation successfully，without intraoperative or postoperative death. The differences in gender，age，BMI，anesthesia ASA score，tumor diameter， distance from tumor to anal margin and tumor stage between the two groups are meaningless（P > 0.05）. There were no significant differences in operative time，intraoperative blood loss，postoperative first exhaust time and hospital stay between the two groups（P > 0.05）. The difference in the incidence of postoperative complications such as abdominal pelvic infection，respiratory tract infection and intestinal obstruction between the two groups is meaningless（P > 0.05）. There was no statistical difference in LARS score and LARS grading between the two groups. The incidence of external intestinal necrosis and anal stenosis in botulinum toxin group was lower than that in modified B group（P < 0.05）. Conclusions For patients with low rectal cancer who will undergo modified Bacon operation，preoperative injection of botulinum toxin into the external anal sphincter can effectively reduce the incidence of postoperative colon ischemic necrosis and anal stricture，and has the same effect as conventional surgery in intraoperative and postoperative complications and anal function recovery. 

Key words:

botulinum toxin, low rectal cancer, modified Bacon operation