ABSTRACT
A striking similarity has been found between the distribution of occlusions in various cerebral arteries and the statistical regularity of the pathways of balloon drifting freely in the blood stream. Based on the assumption that the course of a balloon is determined by the same hydrodynamic laws as that of an embolus of similar size, it is concluded that the majority of occlusions of the cerebral arteries are of embolic origin. Emboli, then, might also be an explanation for most of the TIAs.
Subject(s)
Catheterization , Cerebral Angiography/methods , Intracranial Embolism and Thrombosis/diagnostic imaging , Arterial Occlusive Diseases/diagnostic imaging , Cerebral Arteries , Humans , Intracranial Embolism and Thrombosis/physiopathologyABSTRACT
In 31 of 51 patients with stenosis of the distal segments of the internal carotid artery, the first symptom was a transient ischemic attack. In spite of the high incidence of angiographically proved emboli, 46 patients remained in good neurological condition. Aspirin was given to all patients. In 4 patients a total occlusion developed, causing severe neurological deficit. This indicates that the danger of occlusion is significantly higher than that of embolization. External carotid-internal carotid artery bypass was carried out in 23 patients; occlusion developed during the postoperative observation period in 4 patients without any neurological consequences. It can be concluded that an EC/IC bypass operation is the method of choice in treating patients with severe distal stenosis or recent mural thrombi.
Subject(s)
Carotid Artery Diseases/diagnosis , Adult , Aged , Carotid Artery Diseases/surgery , Carotid Artery Thrombosis/diagnosis , Carotid Artery Thrombosis/etiology , Carotid Artery, External/surgery , Carotid Artery, Internal/diagnostic imaging , Carotid Artery, Internal/surgery , Cerebral Angiography , Constriction, Pathologic , Female , Humans , Male , Middle AgedSubject(s)
Arterial Occlusive Diseases/surgery , Moyamoya Disease/surgery , Adult , Arteriosclerosis/surgery , Basal Ganglia/blood supply , Carotid Artery, Internal/surgery , Cerebral Angiography , Cerebral Arteries/surgery , Diseases in Twins , Female , Humans , Ischemic Attack, Transient/surgery , Moyamoya Disease/geneticsABSTRACT
We find that the media and adventitia of adult human cerebral arteries contain elastic fibers forming a dense, coherent network, similar to that found in muscular arteries of the same size in other organs. The external elastic layer in the adult human is masked for the currently employed staining methods. By treatment with 90% formic acid before fixation, the original staining character of elastic tissue can be restored. The light microscopic and scanning electron microscopic features of this network of elastic fibers are presented.
Subject(s)
Cerebral Arteries/pathology , Elastic Tissue/pathology , Adolescent , Adult , Aged , Amino Acids , Basilar Artery/ultrastructure , Cerebral Arteries/ultrastructure , Child , Circle of Willis/pathology , Elastic Tissue/ultrastructure , Humans , Lysine , Middle AgedABSTRACT
Besides apical medial gaps, lateral and circular medial gaps can be found occasionally at the branching sites of human intracranial arteries, supporting Forbus's idea (1930) of their mechanism of formation and contradicting those put forward by later workers. The large medial gaps situated just distal to the branching sites, considered by Stehbens (1963) to be degenerative in origin, may result from enlargement of congenital multiple apical gaps. Degeneration of the internal elastic layer in the area of medial gaps consists in enlargement and partial fusion of its "physiologic" windows. In contrast to the prevailing opinion, human intracranial arteries do have a well-developed external elastic layer whose density gradually decreases with increasing lengths of the medial gaps. The fundus of a mature aneurysm generally contains no continuous elastic membrane or fiber and relatively little granular elastic material. The equilibrium between partial degeneration and steady reformation of adventitial collagen fibers makes possible the growth of an aneurysm. The thickening of the aneurysmal intima appears to be in causal relationship with the stagnation zones existing in larger aneurysms. In special cases small islets of the arterial media can get into the fundus of an aneurysm, whose spindle-like smooth muscle cells, arranged in a parallel manner, may dissociate themselves from each other and be transformed into spider-like cells.
Subject(s)
Intracranial Aneurysm/pathology , Cerebral Arteries/pathology , Collagen/metabolism , Elastic Tissue/pathology , Humans , Muscle, Smooth, Vascular/pathology , Rupture, SpontaneousABSTRACT
The present paper summarizes our experiences with intraoperative fluorescein angiography in 50 external carotid artery-internal carotid artery bypass operations. This technique has provided precise localization of the ischemic lesion and aided in selecting the sites and direction of the anastomoses to be performed, as well as in checking the patency of the anastomoses and the area supplied by them. A comparison of X-ray angiography with fluorescein angiography indicates the reliability of the latter in the estimation of the area supplied by the anastomosis.
