Role of Indocyanine Green Angiography to Assess Intra-operative Bowel Vascularity and its Association with Post-operative Outcome in Robot-assisted Rectal Resection: a Prospective Indian Cohort Study

Adequate intestinal perfusion is one of the critical factors influencing anastomotic leak (AL) in colorectal surgery. The use of indocyanine green fluoroscence angiography (ICG-FA) intra-operatively to ensure optimal perfusion is being increasingly used. This prospective study aimed to assess the role of ICG-FA in robot-assisted surgery for rectal cancer. This was a prospective cohort study carried out between July 2019 and July 2023, comprising patients undergoing elective robot-assisted rectal resection. The primary objective was to determine the role of ICG-FA in assessing bowel vascularity and in deciding the transection point of the bowel. The secondary objective was to assess the effect of ICG-FA on the post-operative outcomes, and also the effect of the various variables on the ICG staining grade. A total of 50 patients were included. Sixty percent of the patients received pre-operative radiotherapy, including short-course radiotherapy (SCRT) and long-course concurrent chemoradiation (LCRT). A change in transection line based on a less than normal ICG-FA grade was done in 11 patients (22%). Post-operatively, AL was present in 8 patients, out of whom 5 underwent re-operation. Administration of pre-operative RT was the only factor significantly associated with post-operative AL (p < 0.05). The present study showed that a change in the transection point based on the intra-operative ICG-FA was made in 22% of the patients. ICG-FA could hence be used as a potential adjunct to the operative surgeon in assessing the bowel vascularity in a minimally invasive approach like robotic or laparoscopic surgery.