A revised classification of the temporal branches of the posterior cerebral artery.

Purpose: Understanding the vascular variability of the inferior temporal occipital regions is essential for microsurgical approaches to this cerebral zone. To this end, we carried out a microanatomical study of the inferior temporal cortical branches of the posterior cerebral artery (PCA) in order to define their vascularisation territories.

Methods: We studied 40 cerebral hemispheres (20 brains) under an operating microscope. Three brains were fixed in Winkler's solution with latex arterial perfusion and the other 17 brains were fixed in formaldehyde solution.

Results: Our revised classification was based on the following findings. First, the anterior hippocampal artery was always associated with the anterior temporal artery, with the two sharing the vascularisation of the anterior part of the inferior temporal lobe. Second, the middle hippocampal and middle temporal arteries were never present together. Third, the presence of an anterior temporal artery always involved the presence of a posterior temporal artery. Hence, we classified the temporal branches of the PCA into three new patterns. The first pattern includes the anterior and posterior temporal arteries without the anterior hippocampal artery. The second pattern includes the anterior hippocampal artery and anterior and posterior temporal arteries. The third pattern includes the common temporal artery. The first pattern was found most frequently (n = 23, 57.5%), followed by the second (n = 9, 22.5%) and third patterns (n = 8, 20%).

Conclusions: We propose a revised classification of the inferior temporal branches of the PCA that takes into account their vascularisation territories.