New quantitative blood flow assessment of gastric conduit with indocyanine green fluorescence in oesophagectomy: prospective cohort study

BACKGROUND: Anastomotic leakage (AL) remains a critical complication following oesophagectomy, with inadequate perfusion of the conduit identified as a major contributing factor. Although indocyanine green (ICG) fluorescence angiography has been used intraoperatively to assess conduit blood flow, the clinical utility of objective ICG fluorescence indicators for anastomotic site determination has not been well established. This study investigated the association between ICG fluorescence intensity, measured using a new quantitative blood flow assessment technique, and the incidence of AL in patients undergoing gastric conduit reconstruction. METHODS: Prospective analysis of patients who underwent subtotal oesophagectomy with gastric conduit reconstruction between July 2023 and May 2024. Intraoperative real-time perfusion was assessed using the SPY-PHI imaging system in conjunction with SPY-QP software. Quantitative fluorescence intensity measurements were obtained at the terminal branch of the right gastroepiploic artery and the planned anastomotic site. RESULTS: Of 100 included patients, AL occurred in nine patients. Although there was no significant difference in ICG enhancement time between the AL and non-AL groups, fluorescence intensity at both the end of the right gastroepiploic artery (75 versus 101%; P = 0.004) and the anastomotic line (67 versus 90%; P = 0.009) was significantly lower in patients who developed AL. Multivariable analysis identified tumour location in the upper oesophagus and fluorescence intensity ≤ 90% at the anastomotic site as independent predictors of AL, with odds ratios of 6.99 (P = 0.023; 95% confidence interval (c.i.) 1.31 to 37.30) and 12.50 (P = 0.004; 95% c.i. 2.15 to 72.9), respectively. CONCLUSION: Quantitative ICG fluorescence intensity assessment facilitates objective intraoperative evaluation of gastric conduit perfusion and may support optimal anastomotic site selection, potentially reducing AL risk.