What is a precise anatomic resection of the liver? Proposal of a new evaluation method in the era of fluorescence navigation surgery.

Abstract

Indocyanine green (ICG) fluorescence navigation has been adapted for anatomic liver resection (AR) but an objective method for evaluation of its validity is required. This pilot study aimed to propose a new method to evaluate the accuracy of parenchymal division along the plane between hepatic segments and estimate the real-time navigation efficacy for AR by the Medical Imaging Projection System (MIPS), which continuously demonstrates the transection plane using projection mapping with ICG fluorescence. Ten patients who underwent open AR using liver segmentation with ICG fluorescence technique between August 2016 and July 2019 were included: six patients under MIPS guidance (MIPS group), while four using only conventional ICG fluorescence technique before parenchymal resection (non-MIPS group). Densitometry of the captured fluorescence image was performed to evaluate the fluorescence area ratio of each transection plane. The accurate fluorescence area ratio was calculated by subtracting the fluorescence area rate on the resected side from that on the remnant side. The accurate fluorescence area ratio of the MIPS group and the non-MIPS group was 23.0±12.6% and 5.6±9.5%, respectively (P=.038). Based on the results of our new method, real-time navigation using the MIPS may facilitate performing AR along the plane between hepatic segments.