Real-Time Blood Flow Assessment Using ICG Fluorescence Imaging During Hepatobiliary and Pancreatic Surgery with Consideration of Vascular Reconstruction

Abstract

Background/objectives: Indocyanine green (ICG) fluorescence imaging is widely utilized for visualizing hepatic tumors, hepatic segmentation, and biliary anatomy, improving the safety and curability of cancer surgery. However, its application for perfusion assessment in hepatobiliary and pancreatic (HBP) surgery has been less explored.

Methods: This study evaluated outcomes of patients undergoing HBP surgery with vascular reconstruction from April 2022 to August 2024. During surgery, ICG (1.25-5 mg/body) was administered intravenously to assess the need and quality of vascular reconstruction via fluorescence imaging.

Results: Among 30 patients undergoing hepatectomies and/or pancreatectomies, ICG fluorescence imaging was used in 16 cases (53%) to evaluate organ and vascular perfusion. In two hepatectomy cases with consideration of reconstruction of the middle hepatic veins, sufficient fluorescence intensities in drainage areas led to the avoidance of middle hepatic vein reconstruction. In 14 cases requiring vascular reconstruction, fluorescence imaging visualized smooth blood flow through anastomotic sites in 11 cases, while insufficient signals were observed in 3 cases. Despite this, re-do anastomoses were not indicated because the fluorescence signals in the targeted organs were adequate. Postoperative contrast-enhanced computed tomography confirmed satisfactory blood perfusion in all cases.

Conclusions: Real-time blood flow assessment using ICG fluorescence imaging provides valuable information for intraoperative decision-making in HBP surgeries that require vascular reconstruction of major vessels, such as hepatic arteries, veins, and the portal system.

Keywords: hepatobiliary and pancreatic surgery; indocyanine green fluorescence imaging; real-time blood flow assessment; vascular reconstruction.

Figure 1

A case of reconstruction avoidance, using LIGHTVISION® (Patient no. 2). The metastatic liver tumor is located near the MHV ((A), arrow). Mild hepatic congestion was observed during ICG fluorescence imaging (B), but no hepatic congestion was seen in the contrast-enhanced CT after surgery (C). Supplementary Video S1 demonstrated the operative movie in patient no. 2.

Figure 2

A case of insufficient fluorescence imaging, using LIGHTVISION® (Patient no. 5). Hepatic congestion was observed before the reconstruction ((A), circled area). The fluorescence signal at the reconstructed vessel site was insufficient ((B), arrow). Hepatic congestion improved after reconstruction ((C), circled area). Supplementary Video S2 demonstrated the operative movie in patient no. 5.

Figure 3

A case of sufficient and insufficient fluorescence imaging, using LIGHTVISION® (Patient no. 12). The time-series changes in ICG fluorescence signals were observed before ICG administration and at 10, 15, 20, and 30 s after administration (A). The ICG fluorescence signal in the reconstructed vessels was sufficient in the SMV ((A), arrow) but insufficient in the SpV ((A), short arrow). Blood flow in the SMV was clearly observed on contrast-enhanced CT ((B), circled area), whereas no blood flow was observed in the SpV ((C), arrow).

Figure 3

A case of sufficient and insufficient fluorescence imaging, using LIGHTVISION® (Patient no. 12). The time-series changes in ICG fluorescence signals were observed before ICG administration and at 10, 15, 20, and 30 s after administration (A). The ICG fluorescence signal in the reconstructed vessels was sufficient in the SMV ((A), arrow) but insufficient in the SpV ((A), short arrow). Blood flow in the SMV was clearly observed on contrast-enhanced CT ((B), circled area), whereas no blood flow was observed in the SpV ((C), arrow).

Figure 4

A case of sufficient fluorescence imaging with postoperative thrombosis, using LIGHTVISION® (Patient no. 15). The ICG fluorescence signal in the reconstructed vessel was sufficient (A). Blood flow was observed in the reconstructed vessel on contrast-enhanced CT on postoperative day 3 ((B), circled area), but no blood flow was observed on postoperative day 19 ((C), circled area).