Caroticotympanic artery: anatomically a normal branch or a variation of the internal carotid artery?

Most investigators consider the caroticotympanic artery to be a normal branch of the petrous portion of the internal carotid artery, although some authors disagree. The present study was conducted on forty human temporal bones removed from adult cadavers of both sexes. Twenty pieces were injected and dissected under a surgical microscope, 10 pieces were injected and submitted to corrosion, and 10 were injected and diaphanized in order to observe the frequency of the caroticotympanic artery in the petrous portion of the internal carotid artery. The caroticotympanic artery was not observed in any of the pieces submitted to microdissection and was observed in only 1 of the pieces (10%) submitted to corrosion and also in 1 of the diaphanized pieces (10%). In both cases, only one artery was present. Based on the present results showing that the rate of occurrence of the caroticotympanic artery was very low by the three techniques utilized (microdissection 0%; corrosion 10%; diaphanization 10%), it is possible to conclude that, anatomically, the artery should be considered as a variation and not as a normal branch of the petrous portion of the internal carotid artery, in agreement with most literature reports. Copyright 2000 S. Karger AG, Basel