Ligation of Carotid and Vertebral Arteries in Monkeys

Abstract

The mortality resulting from ligation of the common carotid artery in man varies from 7 to 90%, depending on the condition for which the ligation was done, and the age of the patient. The value of pre-ligation compression of the carotid artery to establish collateral circulation, is not definitely established. This work was primarily undertaken to determine the effect of pre-ligation compression of the common carotid in monkeys. Dogs and rabbits seldom develop symptoms after ligation of a common carotid artery, whereas we hoped that monkeys, whose cranial blood supply is quite similar to that of man, would react in a way comparable to man. However, we were unable to cause paralysis or death in monkeys by ligation of a common carotid artery, or by simultaneous unilateral ligation of vertebral, internal, external and common carotid arteries. The ligations were continued in an effort to determine how much alteration of cranial blood supply the monkey would tolerate, and what changes in the brain were produced. 1. The rhesus monkey is unaffected by ligation of a common carotid artery, and in more than one-half of the procedures, will be unaffected by simultaneous ligation of the common, internal and external carotid and vertebral arteries. In no instance did hemiplegia result; in one there was weakness of the opposite side; and in 2, transient ataxia 2. If, in addition to the ligation of the main cervical vessels on one side, the common carotid artery on the other side is ligated, the animals will die, even though the second ligation is done 9 months to a year after the first. The survival of the animals following the first ligation is due to the adequate blood supply obtained from the vessels of the opposite side, as demonstrated by the injection of ink, or of barium solution into the common carotid of one side, and its equal distribution in the superficial vessels of both hemispheres.