Showing papers on "Cerebral Revascularization published in 1980"

Elective extracranial-intracranial arterial bypass in the treatment of inoperable giant aneurysms of the internal carotid artery.

Abstract: Thirteen patients with giant aneurysms of the internal carotid artery (ICA) were treated with ICA ligation and an extracranial-intracranial arterial bypass. A method for establishing a proper superficial temporal artery to middle cerebral artery pressure gradient while maintaining partial flow through the ICA is presented. This procedure allows the anastomosis to become established before full occlusion of the cervical ICA. None of these patients suffered any immediate or delayed ischemic or rebleed complications over an average follow-up period of 18 months.

Subclavian to middle cerebral artery saphenous vein bypass graft

Abstract: ✓ A variation of an extracranial-intracranial arterial bypass is presented. The subclavian artery is used as the donor vessel and the saphenous vein as the graft; thus, a bypass to a cortical branch of the middle cerebral artery can be accomplished. The advantage of this modification is that the saphenous vein, when tunneled subcutaneously behind the ear, is positioned in a straight line from the donor to the recipient vessel. Since the vein lies in the axis of head rotation, turning of the head causes little displacement of the graft, as opposed to a graft from the common carotid artery to the middle cerebral artery. An additional advantage over the superficial temporal artery to middle cerebral artery bypass is the large flow obtained immediately after anastomosis.

The "bonnet bypass". Case report.

Abstract: A saphenous vein bypass graft from the contralateral superficial temporal artery to the ipsilateral middle cerebral artery was performed in a patient who required occlusion of his left common carotid artery. This procedure was used because of the unavailability of an ipsilateral donor artery. The bypass is working well 8 months postoperatively.

Experimental cerebral ischemia.

Abstract: The basic concepts of the pathology and pathophysiology of cerebral ischemia are presented. Special emphasis is given to the changes that occur in the microcirculation and in autoregulation because of their primary role in the pathogenesis of cerebral infarction. The effects of adrenal steroids, barbiturates, and cerebral revascularization are reviewed.

Arterial occlusion following anastomosis of the superficial temporal artery to middle cerebral artery.

Abstract: Symptoms of cerebral ischemia following superficial temporal artery (STA) to middle cerebral artery (MCA) anastomosis are uncommon and are usually related to impaired flow through the anastomosis or occlusion of the cortical receptor artery. In this report, 3 patients are described who developed symptoms of cerebral ischemia after surgery despite a widely patent anastomosis. In each patient, postoperative angiography revealed occlusion of a previously demonstrated high-grade stenosis of the intracranial internal carotid artery (ICA) or MCA. Occlusion of the stenotic artery was probably related to decreased velocity of blood flow through the narrowed vessel resulting from alterations in flow patterns following anastomosis.

Fatal subdural bleeding following superficial temporal-middle cerebral artery anastomosis. Case report

Abstract: This report describes a sudden death during convalescence from superficial temporal artery-middle cerebral artery bypass surgery. Artificial arterial anastomosis introduces the danger of a high-pressure subdural hemorrhage in an unnatural location.

In answer to the question: "As compared to what?" A progress report on the EC/IC bypass study.

Abstract: THE DEVASTATION of a major stroke for an individual and his family needs no elaboration for the readers of this journal. To reduce the incidence of this common catastrophe is the goal and preoccupation of many physicians and surgeons. Into the scientific appraisal of therapeutic measures a new element has entered — modern methodology. There is a growing demand by critical members of our profession for convincing accreditation of measures purported to be effective in stroke prevention. As a result medical, and also surgical, means of stroke prophylaxis have been submitted to this type of enquiry by clinical trials. Pitfalls in design, execution and analysis have been encountered in most studies to date, resulting in criticism and cynicism directed at these trials. Both are welcome as they will lead to improvement in methods for further studies. Critics and cynics can hamper, very seriously, the success of an attempt to validate a therapy because if their voices are authoritative they may persuade practitioners and the public that clinical judgement based on experience, well-remembered anecdotes of happy or unfortunate outcomes, or long series of uncontrolled studies with apparently reduced morbidity and mortality are adequate evidence of effective treatment and preferable to \"experimenting on people.\" Trie development of microsurgery followed the pioneering studies of Donaghey and Yasargil who demonstrated that the blood supply of the scalp could be successfully grafted onto that of the brain with safety and patency in humans as well as in the laboratory. 1-* Subsequently, such surgery has been done frequently enough to convince the most critical that it is a procedure of low morbidity and mortality and a large number of neurosurgeons now can perform EC/IC anastomosis with skill and operative success. Patency rates are high and cerebral blood flow studies often demonstrate quantitative improvement in regional cerebral blood flow. Proposed Indications for EC/IC Anastomosis As a sequel to this technical advance there are several potential clinical applications. The first is the prevention of stroke resulting from deliberate surgical occlusion of cerebral arteries. A number of instances are known where a preliminary bypass has permitted deliberate ligation of middle cerebral or internal carotid arteries in dealing with giant aneurysms or tumors at the base of the brain. These observations have demonstrated that despite the small size of the anastomosis between branches of the superficial temporal artery and the middle cerebral artery sufficient blood can be supplied to prevent …

Effect of omental transposition to the brain on protein synthesis in experimental cerebral ischaemia.

Abstract: Occlusion of the middle cerebral artery severely affects the uptake of labelled leucine into various subcellular fractions from rabbit brain. Previous transposition of pedicled omentum to the cerebral surface maintains to a large extent the protein synthetic activity of the brain following arterial occlusion. The role of the transposed omentum in providing an effective collateral circulation and minimizing the occurrence of irreversible ischaemic lesions is stressed.

Ischaemic intermittent claudication of the masticatory muscles: two case reports.

Abstract: Intermittent claudication of the masticatory muscles is an unusual symptom sometimes described in association with temporal arteritis. We describe here two cases where this symptom was due to insufficient blood supply to the masticatory muscles caused by atherosclerotic changes of carotid vessels. In one of our cases surgical revascularization was followed by the disappearance of this symptom.

Experimental Cerebral Revascularization Studied by 85Kr Clearance and Fluorescein Angiography After 24 Hours of Permanent Occlusion of the Middle Cerebral Artery in Dogs

Abstract: In spite of encouraging clinical results,1,17 the definitive role of extra-intracranial bypass in the prevention and treatment of ischemic cerebrovascular disease needs to be further substantiated. Still required are information from clinical cooperative controlled studies and further experimental analysis of the metabolic and hemodynamic changes as well as of the circulatory patterns that follow revascularization in acute and chronic ischemia.

Hemorrhagic Infarction after Microsurgical Cerebral Revascularization

Abstract: Since the early days of carotid surgery, clinicians have feared that acute revascularization of ischemic brain may result in hemorrhagic infarction. We have recently encountered such a complication after an extracranial-intracranial (EC-IC) bypass graft. Only two similar cases have been reported in the literature.22,28

Medical versus Surgical Treatment of Patients with Cerebrovascular Insufficiency

Abstract: Report on a series of patients suffering from cerebrovascular insufficiency caused by stenosis and/or occlusion of one or several major cerebral vessels. The patients were divided in two groups, one b

Cerebral revascularisation in stroke prophylaxis.

Abstract: Over 700 cerebral vascular operations have been undertaken on the Surgical Unit of St Bartholomew's Hospital, London, for stroke prophylaxis, the majority being carotid endarterectomies. One of the unique features of the latter procedure is the marked instability of postoperative blood pressure. The relation of this change to interference with carotid baroreceptor function was studied by per-operative carotid sinus nerve recording. It was possible to relate nerve activity to the postend-arterectomy changes in the mechanical properties of the vessel wall in the region of the carotid sinus. Postoperative hypotensive episodes could be reversed by the injection of local anaesthetic alongside the carotid sinus nerve through a cannula left in situ at operation. The complications of 425 carotid endarterectomies were analysed by computer and specific risk factors were found to be hypertension, the presence of contralateral internal carotid artery disease, and the presence of lower limb vascular disease. The carotid angiograms of 200 patients were studied with respect to the extent of the disease at the origin of the internal carotid arteries. The operative complication rate was found to be closely related to the severity of this disease, all severe complications occurring in patients with severe bilateral internal carotid artery stenosis or occlusion. This finding has led to the introduction of the term the `reperfusion syndrome', and the mechanism of the complication is still under study. Seventy-nine extraintracranial revascularising procedures have been undertaken and this operation has been shown to carry a very low morbidity. The postoperative incidence of recurrent transitory ischaemic attacks (TIAs) and strokes is low, but the longest follow-up period is still only 4 years. The value of the procedure for TIAs and strokes is under study, as is its place in the treatment of patients with dementia.

Brain tissue pO2 and pCO2 levels before and after cerebral revascularization.

Abstract: Microvascular surgical techniques have made possible the improvement of cerebral blood flow, as demonstrated by angiography and by regional cerebral blood flow research. In this study, simultaneous mass spectrometer determinations of brain tissue and blood PO2, and pCO2, levels were used to evaluate the effectiveness of common carotid-supraclinoid carotid anastomoses (CC-SCA) in dogs. With blood pCO2 maintained at a constant level, the baseline brain tissue pO2 and pCO2 levels were recorded. During the CC-SCA procedure, which involved brain retraction and temporary vascular occlusion, brain tissue pO2 levels fell to 40% of baseline and pCO2 levels rose by 35%. Following restoration of flow via the anastomosis, the brain tissue pO2 and pCO2 levels agina reached baseline.

New Approaches in Cerebral Revascularization

Abstract: With the development of microvascular surgery and improved angiographic techniques the interest of neurologists and neurosurgeons in cerebral vascular disease has increased. These advances have confronted us with patients having complicated vascular lesions requiring innovative surgical approaches. In this paper we will discuss our approach to three such problems.