Circulation-corrected indocyanine green infusion stabilizes blood concentration and improves intersegmental plane identification in thoracoscopic segmentectomy

Abstract This study aimed to improve fluorescence stability during thoracoscopic segmentectomy by controlling the blood concentration of indocyanine green (ICG) through circulatory correction. In this single-centre, prospective, non-randomized study, ICG was infused at a fixed rate (Group C) or at a rate adjusted to cardiac output measured with a minimally invasive haemodynamic monitor (Group F); the primary endpoint was successful marking of all required intersegmental planes. Twenty-nine patients were analysed per group. Marking succeeded more often in Group F (93.1% vs. 58.6%, p = 0.005). Median blood concentrations and fluorescence intensities were similar between groups, but variability differed: the variances of peak blood concentration, fluorescence intensity at the end of marking and time to fluorescence were all significantly smaller in Group F, and fluorescence also appeared earlier (28 vs. 38 s, p = 0.01). Group allocation remained associated with success after adjustment for adhesion grade, segmentectomy type and sex (odds ratio 12.76, p = 0.005). Cardiac output-adjusted infusion was associated with more stable fluorescence and a higher marking success rate. Because cardiac output adjustment also entailed a faster infusion rate, the relative contributions of individualized correction and faster delivery could not be fully separated. Trial registration : UMIN-CTR no. UMIN000047255 Date of registration 1 April 2022.