Intracranial and extracranial circulations in the dog: Anatomic and angiographic studies

Abstract

NINE FIGURESThe dog has been a frequent subject f o r laboratory studies of the cerebral circulation. A detailed description of this circulation was lacking before the work of Ellenberger and Baum (1891) and Tandler (1899). Bouclcaert and Heymans ( ' 3 5 ) added some information as a result of dissections of portions of the cerebral circulation in the course of their physiologic studies. More recently, Jewel1 ('52) gave a detailed anatomic description of the blood vessels of the head of the dog, showing the numerous anastomoses between external and internal carotid systems already known to physiologists. I n the process of conducting experiments on the production of infarcts in the brains of dogs, we realized there was a significant lack of information on the radiologic anatomy of the cerebral blood vessels. Localization of affected vessels was uncertain when seen in roentgenograms of the skull, and this problem could not be solved by referring to the literature.To overcome this deficit, angiograms were done in the living animal. Dissections were then performed after injec-

Experimental regional cerebral ischemia in the middle cerebral artery territory in primates. Part 1: Angio-anatomy and description of an experimental model with selective embolization of the internal carotid artery bifurcation.

“…10 -" Conversely in the subhuman primates, the ICA is very well developed and the maxillocarotid anastomoses could hardly be identified in this study. The pattern of the arterial branching and the relative sizes of the ophthalmic and posterior communicating arteries to the ICA are similar to those of the human brain.…”

“…However, these ECA-ICA anastomoses are not so well developed in subhuman primates as they are in the lower species such as cats and dogs. Moreover, the maxillocarotid anastomotic arteries, which are prominent in cats and dogs, 8 ' 10 could not be clearly demonstrated in monkeys and baboons.…”

“…9 ' 10 The origin of this vessel is located somewhere between 3.5 and 5.0 mm (average 4.0 mm) proximal to the center of the ICA bifurcation (table 1). A group of hypothalamic perforators branch off from this vessel and from its junction to the ICA.…”

Blood flows in the maxillocarotid anastomoses and internal carotid artery of conscious dogs

“…It is therefore concluded that this anastomosis is unlikely to be functionally important in normal conscious dogs. Although this study provides no information about the functional significance of the ascending pharyngeal-internal carotid anastomosis, Jewel (1952) and others (Gillilan, 1976; Torre et al, 1959) concluded that in dogs this anastomosis is of little or no functional significance. Hence, it seems justified to ignore this anastomosis too.…”

“…Anatomic evidence for other anastomoses between the external carotid and intracranial circulations in dogs was described in detail by Jewel1 (1952) and Gillilan (1976). Angiographic studies of these anastomoses were reported by de la Torre et al (1959). However, these studies provided only qualitative descriptions of the anastomoses and none was carried out in conscious dogs.…”