ICG fluorescence imaging for quantitative evaluation of colonic perfusion in laparoscopic colorectal surgery.

BACKGROUND: Fluorescence technology with indocyanine green (ICG) provides a real-time assessment of intestinal perfusion. However, a subjective evaluation of fluorescence intensity based on the surgeon's visual judgement is a major limitation. This study evaluated the quantitative assessment of ICG fluorescence imaging in determining the transection line of the proximal colon during laparoscopic colorectal surgery.

METHODS: This is a retrospective analysis of a prospectively maintained database of 112 patients who underwent laparoscopic surgery for left-sided colorectal cancers. After distal transection of the bowel, the specimen was extracted extracorporeally and then the proximal colon was divided within the well-perfused area based on the ICG fluorescence imaging. We evaluated whether quantitative assessment of intestinal perfusion by measuring ICG intensity could predict postoperative outcomes: F max , T max , T 1/2, and Slope were calculated.

RESULTS: Anastomotic leakage (AL) occurred in 5 cases (4.5%). Based on the fluorescence imaging, the surgical team opted for further proximal change of the transection line up to an "adequate" fluorescent portion in 18 cases (16.1%). Among the 18 patients, AL occurred in 4 patients (4/18: 22.2%), whereas it occurred in only 1 case (1/94: 1.0%) in the good perfusion patients who did not need proximal change of the transection line. The F max of the AL group was less than 52.0 in all 5 cases (5/5), whereas that of the non-AL group was in only 8 cases (8/107): with an F max cutoff value of 52.0, the sensitivity and specificity for the prediction of AL were 100 and 92.5%, respectively. Regarding postoperative bowel movement recovery, the T max of the early flatus group or early defecation group was significantly lower than that of the late flatus group or late defecation group, respectively.

CONCLUSIONS: ICG fluorescence imaging is useful for assessing anastomotic perfusion in colorectal surgery, which can result in more precise operative decisions tailored for an individual patient.