Assessment of the regularity of hepatic arterio-portal anastomosis exploiting in vivo microscopy.
OBJECTIVE
To determine the regularity of hepatic arterio-portal anastomosis (i.e., does every branch of the portal system receive a tributary from the hepatic arterial system and, if so, does it occur at a constant level?).


METHODS
Ten male Wistar mice weighing 50 g each were divided into two groups. The first group underwent portal vein ligation, and the second group underwent ligation of the portal vein, aorta, and inferior vena cava simultaneously. Fluorescence and heparin were injected prior to ligation, via the jugular vein. The liver surface circulation was monitored, using in vivo microscopy before and after ligation.


RESULTS
Prior to ligation, two kinds of blood flow were noticed, fast and slow, regardless of the position of the examined site on the liver surface, in the distributing venules, terminal portal venules, and sinusoids. Following ligation, results were similar in both groups with four types of blood flow: (1) complete cessation of blood flow; (2) respiration-related blood movement; (3) slow blood flow, starting either in the distributing venules, terminal portal venules, or sinusoids; (4) fast blood flow, starting either in the distributing venules, or terminal portal venules or sinusoids.


CONCLUSIONS
The presence of two types of blood flow, before ligation, and the presence of four types of blood flow after ligation, starting at different levels, lead to the conclusion that arterio-portal anastomosis does not follow a regular pattern in the peripheral zone. That is to say, a 1-to-1 ratio does not exist, and, where it exists, it does not occur at a constant level of the vascular tree.
Mohamad
Rabie A
RA
Department of Radiology, Nippon Medical School, Tokyo 113-8603, Japan.
Murata
Satoru
S
Kumazaki
Tatsu
T
D000818:Animals; D001011:Aorta / Q000502:physiology / Q000601:surgery; D001163:Arteriovenous Anastomosis / Q000502:physiology*; D005456:Fluorescent Dyes; D006499:Hepatic Artery / Q000033:anatomy & histology / Q000502:physiology; D008026:Ligation; D008102:Liver Circulation / Q000502:physiology*; D008297:Male; D051379:Mice; D008833:Microcirculation / Q000502:physiology; D008853:Microscopy; D011168:Portal System / Q000502:physiology*; D011169:Portal Vein / Q000502:physiology / Q000601:surgery; D012039:Regional Blood Flow / Q000502:physiology; D012119:Respiration; D014682:Vena Cava, Inferior / Q000502:physiology / Q000601:surgery; D014699:Venules / Q000502:physiology
D005456:Fluorescent Dyes