Assessing Perfusion of Transection Margins In Colorectal Surgery Using Oxygen Saturation Imaging (OSI): Is OSI Comparable To Indocyanine Green (ICG)?

Purpose/Background: Confirming perfusion to the anastomosis is a crucial step in colorectal surgery to prevent anastomotic leak. Indocyanine green (ICG) is widely used to evaluate perfusion to the anastomosis but may not be feasible in settings of ICG contrast allergy or supply shortage. Oxygen saturation imaging (OSI) is a multispectral imaging-based system that offers real-time assessment of tissue oxygen saturation (StO₂) without the need for ICG contrast injection. Studies comparing ICG and OSI in colorectal surgery are limited.

Methods/Interventions: A retrospective case series was performed at a single academic tertiary referral center. Patients undergoing colorectal surgery requiring an anastomosis underwent perfusion assessment of a segment of bowel before transection and creation of an anastomosis using OSI and ICG. OSI was performed laparoscopically and endoscopically using the FUJIFILM Eluxeo Vision System. This device was granted Breakthrough Device Designation by the FDA in 2020. Cases where a demarcation line (DL) was apparent between perfused and less-perfused bowel were included. StO2 levels in the perfused and less-perfused sides were measured postoperatively. OSI was used endoscopically to evaluate intraluminal mucosal perfusion proximal and distal to the staple line when feasible

Results/Outcomes: A total of 19 patients underwent colorectal surgery between 7/2023-5/2025. Indications for surgery included colon cancer (37%), diverticulitis (32%), rectal cancer (21%), Crohn's disease (5%), and large unresectable colon polyps (5%). Procedures performed included right hemicolectomy (37%), sigmoidectomy (32%), low anterior resection with a diverting loop ileostomy (21%) and without (11%). DL were identified in 19 patients using laparoscopic OSI and in 17 using ICG. One did not receive ICG due to allergy, and ICG failed to show DL in another due to venous backflow. Serosal StO2 data was available in 18 patients. The average StO2 of perfused bowel and less-perfused bowel was 77.1% (SD 10.6) and 42.1% (SD 17.7) respectively P< 0.001. Endoscopic OSI was used to measure mucosal StO2 in 10 patients who underwent sigmoidectomy or LAR. Anastomotic mucosal StO₂ was available in 7 patients (proximal and distal). Mean proximal StO2 56.4% (range 13.0% to 73.0%) compared to mean distal StO2 56.6% (range 31.0% to 71.5%).

Conclusion/Discussion: OSI is comparable to ICG for visual assessment of bowel perfusion in colorectal surgery. OSI provides quantitative analysis of tissue oxygenation without need for ICG contrast injection. OSI can be used in settings where ICG cannot be used, such as iodine allergy or ICG supply shortage. In the future, OSI technology can be used in conjunction with ICG angiography to assess perfusion of the tissues