Patient-Specific Functional Liver Segments based on Centerline Classification of the Hepatic and Portal Veins

Abstract Couinaud's liver segment classification has served as the standard basis for liver surgery planning for nearly seven decades. While providing a systematic framework by dividing the liver into eight segments, its reliance on fixed planar boundaries may not always align with individual liver anatomical variations. In this study, we propose a new method for classifying liver functional segments. By integrating patient-specific liver morphology, 3D vascular system, and user-defined landmarks, our approach offers greater flexibility in classifying the liver while respecting individual anatomical variations. We conducted a comprehensive assessment of our method, comparing it with two widely used liver classification techniques: conventional plane-based and portal vein-based classifications. Our results demonstrate that our method's flexibility extends beyond conventional software. By enabling the inclusion of both hepatic and portal veins, including peripheral branches, our approach deviates from the classical Couinaud classification. Importantly, our findings indicate that our approach not only overcomes the limitations of traditional methods but also provides a more precise and surgery-ready definition of liver segments, particularly in complex cases involving segments 5 and 8. Furthermore, feedback from liver surgery specialists highlights its potential benefits, including improved visualization in complex cases and better assessment of vascular perfusion territories.