Selective lenticulostriate occlusion in the primate. A highly focal cerebral ischemia model.

Abstract

SUMMARY A highly reliable model for the study of focal cerebral ischemia has been developed using a retro-orbital approach to occlude the lateral lenticulostriate arteries of the baboon. An infarction of the caudate, putamen and the anterior limb of the internal capsule has consistently been produced. Reliability has been attained because the anatomical variations of the lenticulostriate arteries of each animal can be fully appraised, permitting selective vessel occlusion. A well-defined clinical and radiographic lesion has also resulted from this procedure which was clinically well tolerated by all animals. Selective lenticulostriate occlusion provides a new approach to the study of focal cerebral ischemia in the sub-human primate, and serves for the evaluation of proposed therapies for treatment of focal cerebral ischemia.Stroke, Vol 12, No 5, 1981 AN IMPORTANT GOAL in the study of focal cerebral ischemia is a lower animal model with a lesion that resembles a stroke in man and permits its careful study. 1-2 If the model is to be used for the evaluation of a proposed therapy for focal cerebral ischemia, it must be highly reproducible. When subhuman primates are used, an even higher level of reproducibility is necessary to minimize the number of observations and, therefore, the number of valuable animals required to be studied, in order to draw a conclusion of significance. We report a technique for creating a highly reliable focal cerebral ischemic lesion in the baboon that fulfills these requirements as well as providing a unique opportunity to study the primate microcirculation. This technique depends upon selective occlusion of only the penetrating, lateral lenticulostriate (LLS) arteries. This is a fundamentally different approach from previous primate focal ischemia models which have all involved middle cerebral artery occlusion. ProcedureNine baboons (Papio cynocephalus/anubis) weighing between 8 and 10 kg were anesthetized with ketamine hydrochloride (Ketalar*) 5.0 mg/kg I.M. and pancuronium bromide (Pavulonf) .05 mg/kg. The animals were then intubated and ventilated on a respirator as guided by frequent blood gas determinations. Femoral arterial and venous catheters were inserted for monitoring arterial pressure and for the delivery of normal saline solution.• In order to expose the origins of the LLS arteries without brain retractions, we used a modified retroorbital approach. 8 The animals' heads were secured in a stereotaxic frame $ and the sagittal plane tilted 10°t oward the side of the surgery. After the skin about the right eye and temple was shaved and surgically prepared, a curvilinear incision was made around the lateral half of the orbit just cranial to the zygoma for approximately 1W inches. The temporalis and masseter muscles were incised and retracted away from the lateral orbital wall. Subperiosteal dissection was then extended into the lateral orbit. To provide additional space for exposure of the apex of the orbit, the posterior chamber of the eye was entered with a 22 gauge needle, ...

Experimental Model of Lacunar Infarction in the Gyrencephalic Brain of the Miniature Pig

“…This high reproducibility is possible because the individual anatomical variations of the AchA can be appraised, thus allowing selective occlusion of the perforating brain vessels such as the functional end artery. 16 In contrast, the middle cerebral artery occlusion model involves leptomeningeal anastomoses, which are undoubtedly responsible for the repeated observations of significant distal blood flow and for the variations in the size of the resulting infarction. 12 Neurophysiological changes were assessed by MMEP monitoring, which can record pyramidal tract function in real time 17 based on the concept that the AchA provides blood flow to the IC region.…”

A Modified Transorbital Baboon Model of Reperfused Stroke

“…To address this issue, several models of primate stroke have been reported, dating back to the early 1970s (Table 3). 18,[22][23][24][25][26][27][28][29][30][31][32][33][34] Most of these are based on occlusion of the MCA in either macaques or baboons and use several techniques, including the following: intraluminal M1 embolization, 26,31,35 extraluminal M1 ligation, 25 lenticulostriate interruption, 28 -30 and either permanent or temporary M1 clipping. 22,23,27,[32][33][34] Unfortunately, the vast majority of the reports before 1980 involved qualitative assessments of neurological dysfunction and infarct volume, making assessment of their utility difficult.…”

“…48 While these other models have added much to the understanding of primate vascular anatomy, they have generally been considered inferior for a variety of reasons. The use of electric coagulation to create occlusion of the lenticulostriate arteries 29 or the posterior choroidal artery 46 was associated with potential damage to adjacent cerebral tissue. The unpredictable localization of embolic material within MCA branches resulted in variable deep or cortical infarcts.…”

Experimental acute thrombotic stroke in baboons.

“…12 -30 From prior carmine gelatine perfusion experiments, the extent of cerebral infarction following proximal MCA ligation or electrocoagulation-induced occlusion has been localized to the lenticulostriate and perforating vessels. 27 - 28 In those experiments the patency of the lenticulostriate or perforating arteries was not examined.…”

“…Although the principal blood supply to the posterior lateral portion of the corpus striatum in the baboon is derived from the lenticulostriate arteries, variability in the distribution of the lenticulostriate arteries and anatomic variants with regard to their origin in the baboon have been described. 27 The actual site of placement of the silastic balloon device about the MCA in this model is, therefore, important in determining the functional outcome after its inflation.…”