Endoarterectomy of common carotid artery in SHR as a model for neurosurgical approach.

When SHR develop hypertension, accelerated vascular noncollagenous and collagenous protein synthesis (adaptive metabolic change, Yamori, 1974) results in the hypertrophy and hyperplasia of the media (adaptive structural change, Folkow, 1958) and in arteriosclerosis due to the increased collagen. As such a thickened arterial wall can be a suitable experimental model for sclerotic arteries in aged man, vascular systems of aged SHR were utilized as model for microvascular surgery using microsurgical technique (Ohtsubo et al: Jap Heart J 16: 309, 1975). The most popular surgical therapy for the occlusion of the intracranial arteries at present is the anastomosis between superficial temporal artery and middle cerebral artery (STA-MCA). However, by this technique, only the cortical branches of MCA are perfused and blood supply into the deep perforating arteries can not be expected. As the predilection sites of occlusion in MCA is the MI portion, thromboendoarterectomy directly applied to this MI portion appears to be more beneficial therapy after the occlusion of MCA. However, there is no report of successful thromboendoarterectomy at such a small artery, the external diameter of which is 2 to 3mm. Therefore, thickened cervical carotid arteries of SHR were used as the model of the M1 portion of MCA and endoarterectomy was attempted to obtain the basic information about sufficient conditions necessary for successful surgical removal of thrombi in such a small artery without causing further obstruction after the operation.