Morphometric Study of the Anterior Thalamoperforating Arteries

Abstract

ObjectiveTo evaluate the morphometry of the anterior thalamoperforating arteries (ATPA).MethodsA microanatomical study was performed in 79 specimens from 42 formalin-fixed adult cadaver brains. The origins of the ATPAs were divided into anterior, middle, and posterior segments according to the crowding pattern. The morphometry of the ATPAs, including the premammillary artery (PMA), were examined under a surgical microscope.ResultsThe anterior and middle segments of the ATPAs arose at mean intervals of 1.75±1.62 mm and 5.86±2.05 mm from the internal carotid artery (ICA), and the interval between these segments was a mean of 3.17±1.64 mm. The posterior segment arose at a mean interval of 2.43±1.46 mm from the posterior cerebral artery (PCA), and the interval between the middle and posterior segments was a mean of 3.45±1.39 mm. The mean numbers of perforators were 2.66±1.19, 3.03±1.84, and 1.67±0.98 in the anterior, middle, and posterior segments, respectively. The PMA originated from the middle segment in 66% of cases. A perforator-free zone was located >2 mm from the ICA in 30.4% and >2 mm from the PCA in 67.1% of cases.ConclusionMost perforators arose from the anterior and middle segments, within the anterior two-thirds of the posterior communicating artery (PCoA). The safest perforator-free zone was located closest to the PCA. These anatomical findings may be helpful to verify safety when treating lesions around the PCoA and in the interpeduncular fossa.

A Ruptured Large Thrombosed True Posterior Communicating Artery Aneurysm Treated with Endovascular Treatment Three Times

“…The most common perfusion areas of ATPAs are the posterior hypothalamus, anterior thalamus, subthalamus, optic tract, tuber cinereum, mammillary body, posterior limb of the internal capsule, and cerebral peduncle. [9][10][11]13,14) The areas vary based on the development of adjacent arteries. For example, the anterior third of the internal capsule is generally supplied with ATPAs, whereas the anterior choroidal artery (AChA) supplies the posterior two-thirds; however, the ATPA supplies almost the entire internal capsule when the AChA is hypoplastic.…”

“…15) Damage of ATPAs can lead to amnesia, subcortical cognitive disturbances, endocrine dysfunction, visual field defects, vegetative disorders, hyperthermia, motor weakness, and sensory and personality changes. 13) The largest ATPA terminates between the mammillary bodies and the optic tract, such as the premammillary area, and the perforator is called the PMA or thalamotuberal artery. Rarely, the PMA originated from the P1 or P2 segment.…”

“…Some reports showed double or triple PMAs. 13,14,16) Gibo et al 14) reported fusion 3D-RA image of the ICAG and VAG was very useful to evaluate the complex anatomical structures around the aneurysm and identify the P1-P2 junction.…”

“…According to several cadaveric studies, the number of ATPAs was 1 to 14 (average, approximately 5-7). [9][10][11][12][13] Vicentelli et al 11) divided the PCoA perforators into inner and outer groups. The former consisted of 3-11 tiny branches supplying the hypothalamus and the latter consisted of 2-7 branches.…”

“…Saeki et al 9) reported that more branches arose on the anterior half of the PCoA in 54%, the posterior half in 25%, and equal halves in 21% of cases. Kim et al 13) examined 80 cadaveric PCoAs, dividing them into three parts, and found that the number of perforators arising from each part was 2.66, 3.03, and 1.67, respectively. Beumer et al 12) examined the length of the perforator-free zone (PFZ) of the PCoA, and 80% of the longest PFZs were located closer to the PCoA diameter around the aneurysm was 1.5 mm; therefore, we could not use a stent.…”