Does indocyanine green improve the evaluation of perfusion during laparoscopic colorectal surgery with extracorporeal anastomosis

BACKGROUND: There has been recent interest in indocyanine green (ICG) to assess anastomotic perfusion in colorectal surgery. We describe our experience using ICG when performing laparoscopic segmental colorectal resections with extracorporeal anastomotic technique and a highly standardized approach for clinically assessing blood flow. METHODS: We recruited 20 consecutive patients to undergo segmental laparoscopic resection and determined an appropriate point to transect mesentery proximally confirming pulsatile arterial flow at this level. Once confirmed, we did a further perfusion study using ICG to ascertain if this would change intraoperative decision-making. RESULTS: Twenty segmental colonic resections were assessed in nine female and 11 male patients aged 26-91 years. ICG administration was safe with no adverse outcomes documented. ICG demonstrated anastomotic perfusion in all cases. We observed no cases wherewith pulsatile blood flow at the cut edge of the mesentery, ICG showed inadequate perfusion at this level. We did find in 25% of cases ICG showed perfusion beyond the cut edge of the mesentery to a distance of up to 2.5 cm. CONCLUSION: ICG perfusion is safe and straightforward to carry out. However, when pulsatile arterial bleeding is demonstrated clinically it does not add anything to assessment of perfusion in our study. Furthermore, in 25% of cases perfusion can be demonstrated beyond the cut edge of the mesentery up to a distance of 2.5 cm. This raises the possibility that an organ well perfused with ICG may have less than ideal blood flow when assessing for this with a view to constructing an anastomosis.