Analyzing the human liver vascular architecture by combining vascular corrosion casting and micro‐CT scanning: a feasibility study

Abstract

Although a full understanding of the hepatic circulation is one of the keys to successfully perform liver surgery and to elucidate liver pathology, relatively little is known about the functional organization of the liver vasculature. Therefore, we materialized and visualized the human hepatic vasculature at different scales, and performed a morphological analysis by combining vascular corrosion casting with novel micro-computer tomography (CT) and image analysis techniques. A human liver vascular corrosion cast was obtained by simultaneous resin injection in the hepatic artery (HA) and portal vein (PV). A high resolution (110 lm) micro-CT scan of the total cast allowed gathering detailed macrovascular data. Subsequently, a mesocirculation sample (starting at generation 5; 88 9 68 9 80 mm³) and a microcirculation sample (terminal vessels including sinusoids; 2.0 9 1.5 9 1.7 mm³) were dissected and imaged at a 71-lm and 2.6-lm resolution, respectively. Segmentations and 3D reconstructions allowed quantifying the macro-and mesoscale branching topology, and geometrical features of HA, PV and hepatic venous trees up to 13 generations (radii ranging from 13.2 mm to 80 lm; lengths from 74.4 mm to 0.74 mm), as well as microvascular characteristics (mean sinusoidal radius of 6.63 lm). Combining corrosion casting and micro-CT imaging allows quantifying the branching topology and geometrical features of hepatic trees using a multiscale approach from the macro-down to the microcirculation. This may lead to novel insights into liver circulation, such as internal blood flow distributions and anatomical consequences of pathologies (e.g. cirrhosis).

Simulation Model of Microsphere Distribution for Selective Internal Radiation Therapy Agrees With Observations

“…The mean diameters of the various artery generations (g) exponentially decreased with each artery generation, in agreement with Debbaut et al (12):…”

“…Furthermore, Debbaut et al (12) demonstrated that the branching pattern of the artery tree is highly variable and that a dichotomous bifurcation model in which a parent artery is divided into two daughter arteries is an overly simplified version of a native hepatic artery tree. In fact, the estimated number of arteries in human livers is 100-fold higher than the number of arteries in a dichotomous bifurcation model because of parent artery division into three or more daughter arteries and the existence of small side branches that are almost perpendicular to the parent artery (12). In addition, the terminal ending of the artery tree is a complex structure, in contrast to the portal vein system where the terminal portal veins straightforwardly continue with the sinusoids into the hepatic lobule.…”

“…A C C E P T E D ACCEPTED MANUSCRIPT 5 of vessel diameter ranged from 0.13 to 0.21 across vessel generations, resulting in considerable variation in artery architecture and thus in the potential for variation in circulatory characteristics within artery generations (12). Furthermore, Debbaut et al (12) demonstrated that the branching pattern of the artery tree is highly variable and that a dichotomous bifurcation model in which a parent artery is divided into two daughter arteries is an overly simplified version of a native hepatic artery tree.…”

Porcine liver vascular bed in Biodur E20 corrosion casts

“…The only exception is a human liver discarded for transplantation that was casted using Batson's 17 [6,7]. Batson's 17 appeared to be suitable for CT scanning, but the quality of the microvessel bed replica has only been demonstrated on a small-volume sample.…”

“…The most commonly used resins (Table 1) are methyl methacrylates such as Mercox [2] or modified Batson's 17 [5,6]. Methyl methacrylates are generally capillary-passable and alcohol non-resistant.…”