Definition of the anterior choroidal artery territory in rats using intraluminal occluding technique

This manuscript delineates the territory of the anterior choroidal artery ( AChA) in rats, as defined by the induction of an AChA infarction. By advanc ing a 0.24-mm surgical suture up the internal carotid artery (ICA) to a poi nt 0.5-2 mm proximal to the middle cerebral artery (MCA) origin, the AChA c ould be occluded and a reliable AChA distribution infarction was produced i n 62% (23/37) of animals. The infarct volume, as defined by TTC staining, w as 55+/-7 mm(3). Maps of the infarction, generated by measuring the entire area of overlapping coronal slices, demonstrated that the internal capsule was always damaged. Other areas that might be affected included the hippoca mpus, thalamus, amygdaloid complex, piriform cortex, dorsal caudatoputamen, and lateral ventricular wall. Positioning the coated suture proximal to th e AChA produced a much smaller infarct involving the medial and lateral hyp othalamus, preoptic region, optic chiasm, and marginal region of the intern al capsule near to the lateral hypothalamus exempt from AChA territory dama ge. A causative relationship between AChA occlusion and a deep cerebral inf arct centered on the internal capsule was further established by: (1) ident ifying the AChA on the non-ischemic side with colored silicone perfusion, a nd subsequent similar delineation on the ischemic side, and (2) delineating infarction in the silicone perfused AChA region using hematoxylin and eosi n staining and the TUNEL method. The AChA usually originated from the ICA ( 91% of cases), 1.75+/-0.12 mm proximal to the MCA bifurcation. Approximatel y 27% of the AChAs had periamygdaloid branch(es) on its initial segment. (C ) 2000 Elsevier Science B.V. All rights reserved.