Anatomy of hepatic arteriolo‐portal venular shunts evaluated by 3D micro‐CT imaging

Abstract

The liver differs from other organs in that two vascular systems deliver its blood -the hepatic artery and the portal vein. However, how the two systems interact is not fully understood. We therefore studied the microvascular geometry of rat liver hepatic artery and portal vein injected with the contrast polymer Microfil â .Intact isolated rat livers were imaged by micro-CT and anatomic evidence for hepatic arteriolo-portal venular shunts occurring between hepatic artery and portal vein branches was found. Simulations were performed to rule out the possibility of the observed shunts being artifacts resulting from image blurring. In addition, in the case of specimens where only the portal vein was injected, only the portal vein was opacified, whereas in hepatic artery injections, both the hepatic artery and portal vein were opacified. We conclude that mixing of the hepatic artery and portal vein blood can occur proximal to the sinusoidal level, and that the hepatic arteriolo-portal venular shunts may function as a one-way valve-like mechanism, allowing flow only from the hepatic artery to the portal vein (and not the other way around).

Quantitative analysis of hepatic macro‐ and microvascular alterations during cirrhogenesis in the rat

“…; Van Steenkiste, ; Debbaut, ; Kline et al. ). In addition, cirrhosis is considered the principal cause of intrahepatic portosystemic shunts (Lutz et al.…”

“…In contrast, new vessels may originate to support the blood supply and venous drainage of the regenerative nodules. The resulting neovasculature is primarily located in the fibrotic regions and bypasses functional liver tissue, thereby aggravating the liver insufficiency (Hano & Takasaki, 2003;Vanheule et al 2008;Van Steenkiste, 2010;Debbaut, 2013;Kline et al 2014). In addition, cirrhosis is considered the principal cause of intrahepatic portosystemic shunts (Lutz et al 2004), although the majority of portosystemic shunts observed in PHT are extrahepatic.…”

New methods for objective angiogenesis evaluation of rat nerves using microcomputed tomography scanning and conventional photography

“…Histomorphometric analyses are used to describe angiogenesis, but are limited in the ability to identify the three‐dimensional (3D) interconnectivity of the vasculature in serial histological sections (Kline et al, ; Perrien et al, ) and focuses on representing superficial blood flow (Zagorchev et al, ). Connectivity defines the maximal number of branches that may be cut without separating the structure (Zagorchev et al, ).…”

“…As technology continues evolving, modern micro‐CT systems are more commonly available and are capable of generating very small voxels with short scan acquisition times allowing both ex vivo and in vivo scanning (Zagorchev et al, ). Moreover, due to voxels as small as 1 μm, the vascular system in rat and even mice could now be visualized (Deshpande et al, ; Kline et al, ; Lee, Barbe, Scalia, & Goldfinger, ; Perrien et al, ). As perfusion with a radiopaque contrast agent is the only requirement to delineate the vascular tree, a close‐meshed network of smaller vessels, contrast enhanced micro‐CT can become a powerful tool in quantifying angiogenesis (Perrien et al, ).…”

Nodule-in-Nodule Imaging Pattern in Hepatocellular Carcinoma Treated by Transarterial Chemoembolization – a Multiparametric Magnetic Resonance Imaging Study

“…There is continued interest for its various procedures and chemotherapeutic agents used despite potential risks and complications [6]. After the successful occlusion of the arterial blood flow of the malignant nodule, the portal blood regurgitation into the adjacent sinusoid vessels may favor tumor remnants, thus reducing the efficacy of TACE [7,8].…”