Intra-operative Transanal Near Infrared Imaging of Colorectal Anastomotic Perfusion: a Feasibility Study

Aim: Anastomotic dehiscence is a devastating complication. Inadequate blood supply is felt to be the prevailing cause. This study describes the use of near infrared imaging to evaluate transanally anastomotic tissue perfusion following low anterior resection.

Method: Twenty patients undergoing low anterior resection for benign and malignant disease were studied. After completing the anastomosis, indocyanine green (ICG) was injected via a peripheral intravenous catheter. An endoscopic near infrared imaging system (Pinpoint, Novadaq, Canada) was then used transanally to visualize mucosal perfusion of the colon, rectum and the anastomotic staple line.

Results: All patients underwent a technically successful ICG angiogram. The angiogram was abnormal in four patients. Two of these had a protective loop ileostomy and showed no sign of anastomotic breakdown. The other two patients were found on CT scan to have a peri-anastomotic collection consistent with anastomotic leakage. Both were managed conservatively with resolution.

Conclusion: This study confirms that transanal ICG angiography is feasible and provides imaging of mucosal and anastomotic blood flow. The technique warrants further study in a larger group of patients to assess its ability to identify defects in tissue perfusion that may lead to anastomotic breakdown.