Extra-intracranial Arterial Bypass Research Articles

Moya-Moya-Syndrom und Schwangerschaft

Background: Moyamoya (puff of smoke) is the Japanese name for a cerebral angiographic picture of bilateral intracranial carotid artery occlusion associated with telangiectatic vessels in the region of the basal ganglia. In childhood the condition usually presents as hemiplegia of sudden onset and epileptic seizures; adults more commonly develop intraventricular hemorrhage. The disease occurs mainly in females. The incidence is about 0.07% in Japan. Case report: A 25-year-old primigravida with moyamoya disease developed sudden intraventricular hemorrhage and loss of consciousness at 24 weeks' gestation. She underwent bilateral ventricular drainage and anticoagulation during a 3-week period in the intensive care unit. A healthy girl was delivered by cesarean section at 34 weeks' gestation. Extra-intracranial arterial bypass surgery was performed some months after delivery. Ten months later the patient shows only mild neurologic deficits. Conclusion: This suggests that prompt diagnostic measures and aggressive treatment can lead to acceptable maternal and neonatal outcome in pregnant patients with moyamoya disease.

Neurological improvement in chronic ischemic stroke following surgical brain revascularization.

50 patients suffering from completed ischemic stroke in the carotid territory for at least two months (17 mild, 31 moderate, 2 severe strokes) underwent extra-intracranial arterial bypass surgery. Neurological improvement was obtained in 43 cases; it persisted in time in 40 cases. Quantitative evaluation of motor performance in 21 patients showed that the degree of improvement was highly significant. Several factors strongly indicate a causal relation between surgical revascularization and neurological restoration. The positive surgical result is strictly dependent on correct patient selection and, in particular: i) on the documentation of local hemodynamic insufficiency; ii) on the occurrence of transient neurological (and to a certain extent EEG) improvement following hyperbaric oxygenation. The latter can also provide reliable information on the minimum degree of improvement to be expected from surgery.

Surgical treatment of cerebrovascular occlusive disease. A follow-up study.

This prospective open study of 124 patients [80% with completed stroke (CS), 16% with TIAS, 4% with PRIND] consecutively admitted between 1976 and 1981 investigates the rates of reinfarction after surgical treatment (extra-intracranial arterial bypass, EIAB and/or carotid thrombendarterectomy, TEA). 34% of patients had unilateral carotid stenosis, 26% unilateral internal carotid artery occlusion, 17% had occlusion of one and stenosis of the contralateral internal carotid artery, 14% bilateral carotid stenosis. Combined surgical morbidity and mortality was 5% after 158 operations in 124 patients; 7 of the 8 complications occurred in patients with CS. Of the 120 survivors in the immediate postoperative period, after a mean follow-up period of 5.7 years ranging from 3-8 years, an infarct occurred in 5.8%, i.e., 1% per year; 3 of them occurred ipsilaterally, 2 contralaterally to the first infarct, two remained unknown. Among all 99 patients with CS, the reinfarction rate was 5% (1% per year); in CS patients with a minimal follow-up of 5 years, the annual reinfarction rate was 2%. Of fifty-three patients with completed stroke after EIAB with a mean follow-up of 4.6 years, 3.8% suffered reinfarction (0.8% per year). Among 26 patients with CS and unilateral carotid occlusion after a mean follow-up of 4.7 years, the reinfarction rate was 3.9% (0.8% per year). Among 46 patients with carotid occlusion with or without further stenotic or occlusive lesions, the reinfarction rate was 2.2%.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of extra-intracranial arterial bypass on cerebral blood flow and oxygen metabolism in humans.

Twelve patients, eleven with a carotid obstruction and one with an occlusion of the middle cerebral artery, were studied before and after a successful unilateral extra-intracranial arterial by-pass, (EIAB) using PET and the 15-0 steady-state technique to measure regional cerebral blood flow (CBF), oxygen extraction fraction and oxygen metabolic rate (CMRO2). In the whole group of patients, both CBF and CMRO2 increased significantly on both cerebral hemispheres after EIAB, returning toward control levels defined in age-matched subjects. Mean oxygen extraction fraction, on the other hand, was not affected. Individually, three different effects of EIAB emerged: 1) Alleviation of a state of long standing unilateral "misery-perfusion", as reported earlier; 2) parallel increase of CBF and CMRO2 bilaterally, which appeared due to improvement of a hemodynamic depression of metabolism, the precise mechanism of which remains obscure; 3) Complex, unexpected changes in the CBF-CMRO2 couple again resulting in increases in CMRO2. This metabolic improvement afforded by EIAB in our patients has not been reported before; it suggests that long-standing hemodynamic failure may induce a metabolic depression that is still potentially reversible by surgical revascularization.

Extra-intracranial bypass surgery for vertebrobasilar insufficiency due to obstructive vertebral artery and vertebral-basilar artery junction disease.

This report is on 19 patients with vertebrobasilar insufficiency in whom direct extra-intracranial arterial bypass surgery to the posterior circulation was performed. In all patients preoperative angiography had demonstrated vascular lesions of haemodynamic significance of either one or both vertebral arteries (VA) or within the vertebral-basilar artery junction (VABAJ). The bypass procedure was performed between the occipital artery (OA) and - depending on the localization of the obstructive vascular lesion - the posterior inferior cerebellar artery (PICA), the VA or the anterior inferior cerebellar artery (AICA). A modification of the operative technique is presented with using a paramedian approach. The clinical results of this series support the concept that a patent extra-intracranial graft to the posterior circulation may have a protective effect by preventing further ischaemic events.

Long-term follow-up in 257 ICA occlusion: comparison between EIAB-treated and untreated patients.

The purpose of this paper is to estimate the real value of the Extra-Intracranial Arterial Bypass (EIAB) in preventing or reducing further and more catastrophic ischaemic events in patients suffering from an Internal Carotid Artery (ICA) occlusion. 257 patients, suffering from ICA occlusion, are considered retrospectively: 122 of them submitted to EIAB and 135 medically treated or untreated. In both groups, homogeneous by sex, age, neurological grading distribution and length of follow-up, the following parameters were considered: the incidence of ischaemic recurrences during the follow-up period; the characters of the recurrences with particular reference to the fatal stroke; the rate of ischaemic events per year. The comparison between the outcome in surgically treated patients and in "untreated" ones indicates that the EIAB can be effective in preventing or reducing the ischaemic recurrences and the frequency of fatal stroke in TIA-, RIND, or stroke-patients suffering from ICA occlusion.

Angiographic technique in extra-intracranial arterial bypass for cerebral ischemia.

Angiography is indispensable for the selection of appropriate candidates for extra-intracranial arterial bypass (E.I.A.B.). It allows the visualization of ICA and/or MCA occlusion or inaccessible stenosis which are considered indications for E.I.A.B. Complete angiographic study also gives information about other vascular lesions and the morphology of ECA and its branches as well as collateral circulation. Moreover angiography evaluates the result of bypass. The methods of the preoperative and postoperative angiography are described.

Extra-intracranial arterial bypass in typical carotid reversible ischaemic deficits: long-term follow-up in 100 patients.

The long-term follow-up of 100 consecutive patients who suffered from a reversible ischaemic attack (RIA) in the carotid territory and were submitted to extra-intracranial arterial bypass (EIAB) surgery in seven Italian Neurosurgical Centres is reported. The preoperative angiographic and clinical features, and the surgical complications are reported. The follow-up ranged from two to seven years with a mean of thirty-five months. In this period in the territory served by the bypass only two completed strokes and six RIAs occurred. Four patients died, only one for cerebral ischaemic problems. The results of the present series have been compared with those of the literature: they appeared consistent with other surgical series and clearly better than those of medical treated patients. The EIAB can then be considered a good therapeutic choice for the treatment of RIAs in carotid territory.

Bilateral occlusive carotid disease: simultaneous or staged operation?

In a series of 231 carotid operations in 202 patients, 8 patients were operated on bilaterally by staged (group A), and 15 patients by simultaneous procedures (group B). Additionally 4 patients had a combined external carotid desobliteration plus extra-intracranial arterial bypass (group C), 3 of them in a simultaneous operation. Patients of the groups A and C had an uneventful recovery throughout. An additional group A patient, however, died during the staging interval due to an ischemic cerebral infarction at the not-yet-operated side. In group B one patient died after myocardial reinfarction and 4 showed other complications: diffuse hematoma of the neck, temporary palsy of the hypoglossal nerve, temporary left brainstem deficit and respiratory failure. Nevertheless, it is concluded that simultaneous bilateral carotid reconstruction offers specific benefits i.e. no risky interval, no second anesthesia and a reduced hospitalization period, and can therefore be recommended in selected cases.

Frequency changes of sensorimotor EEG rhythm after revascularization surgery

In a group of 26 patients undergoing extra-intracranial arterial bypass surgery (EIAB), the frequency of sensorimotor rhythms was measured shortly before and 7 days after EIAB surgery. Bipolar EEG recording from both central regions was used for calculation of power spectra and measurement of peak frequency to determine the dominant frequency of the sensorimotor rhythm. Preoperative hemispheric comparisons displayed a statistically significant frequency decreased (−0.47 Hz) on the ischaemic side, only in the group (15 patients) with cortical infarction. The hand pressure, measured electronically, showed a tendency to decrease in the early postoperative stage. Measurement of the frequency, however, showed a significant decrease of −0.35 Hz on the operated side, only in the group with cortical infarction, whereas no frequency decrease was found in the other group. This unilateral postoperative frequency decrease in patients with cortical infarction is interpreted as a temporary deterioration of brain function.

The influence of skull defects and reperfusion after extra-intracranial arterial bypass surgery on the sensorimotor EEG rhythm.

Twelve patients with small burr hole skull defects after extra-intracranial arterial bypass surgery were studied. The amplitude and frequency of the sensorimotor rhythm were measured 7 days and 1, 2, 4, and 6 months after surgery in follow-up EEGs from the central region. Seven patients showed a frequency decrease (compared with preoperative measurement) on the operated side 7 days and/or 1 month after surgery. There was no case of frequency decrease 6 months after surgery; four patients displayed a late frequency increase. Ipsilateral amplitude enhancement was never found 7 days postoperatively, but after 6 months in nine patients. Such physical factors as burr holes and bone replacement can only partially explain the amplitude enhancement, and cannot explain the frequency decrease. It may be assumed that temporary clamping of the middle cerebral artery and/or reperfusion of an ischaemic area result in a brief deterioration of brain function, as indicated by frequency slowing and delayed amplitude enhancement; related observations were made in patients with cerebrovascular disorders and mild to moderate neurological deficit about 20 days after the onset and correlated with clinical recovery.

Angiographic aspects of extra-intracranial arterial bypass (EIAB) for cerebral arterial occlusive disease.

Fifty extra-intracranial arterial anastomoses were performed in 48 patients. The importance of a precise angiographic study in the pre- and post-operative period is emphasized. The different angiographic patterns of the anastomosis, its variation in time, the possible cause of failure, and the role played by the EIAB on the cerebral blood flow are described and discussed. The problems of extension and time of the postoperative angiographic examination, are also discussed.

Evaluation of patients undergoing extra-intracranial arterial bypass surgery based on CT-scanning and neurophysiological studies.

In order to evaluate short-term effects of extra-intracranial arterial bypass procedure (EIAB) on cerebral function, we performed neurophysiological studies, combined with CT-evaluation, on 17 patients undergoing EIAB, pre- and postoperatively. CT helps to define, on a morphological basis, the extent of ischemic brain damage, and is, in some cases, a valuable tool in preoperatively assessing chances for a recovery. EEG shows, 2 weeks after surgery, in 50% of the patients after completed stroke, worsening of ischemic lesions as a result of reduced intraoperative cerebral perfusion and/or temporary occlusion of the recipient cortical vessel.

Some thoughts on extra-intracranial arterial by-pass techniques.

The author recalls the different possible techniques of extra-intracranial bypass that may be used to revascularise an ischaemic brain.

Late False Aneurysm of the Carotid Artery

A patient with a rapidly enlarging symptomatic false aneurysm of the internal carotid artery 30 years after nonoperative treatment of a penetrating neck injury is presented. Preoperative compression of the aneurysm precipitated transient cerebral ischemic attacks. Complete interruption of the right internal carotid artery inflow during aneurysmectomy was considered to be fraught with great danger. An extra-intracranial arterial bypass was therefore performed, and then aneurysmorrhaphy was easily performed and saphenous vein graft interposition accomplished. The importance of early definitive treatment of arterial injuries is emphasized. The bypass used allowed additional cerebral blood flow when complete occlusion of the carotid artery was contraindicated.

Surgical Results of Extra-intracranial Arterial Bypass for Ischemic Brain during the Recent Five Years

Surgical Results of Extra-intracranial Arterial Bypass for Ischemic Brain during the Recent Five Years

Results of microsurgical extra-intracranial arterial bypass in the treatment of cerebral ischemia.

The authors report the operative and follow-up results (3 months to 9 years) of 86 consecutive extra-intracranial bypass operations on 84 patients with cerebral ischemia, emphasizing both the prophylactic role of the operation in preventing further catastrophic cerebral ischemia, and the low morbidity and mortality of the operation.

Results of microsurgical extra-intracranial arterial bypass in the treatment of cerebral ischemia

Results of microsurgical extra-intracranial arterial bypass in the treatment of cerebral ischemia

Narrowing and occlusion of arteries by intracranial tumors. Review of the literature and report of 25 cases.

The intracranial arterial obstructions (narrowing or occlusion) found with intracranial tumors are rarely reported. Our 25 cases and those of the literature enable us to draw a statistical view of these facts. Meningiomas and gliomas are often concerned, and they principally involve the main arteries at the base of the brain. The practical interest in such pathology concerns: the risk of a fall in blood pressure during general anesthesia which may result in occlusion of a narrowed artery; the need to estimate the pathological state of one or several arteries passing by a tumor which must be removed; and the possibility of providing an extra-intracranial arterial bypass if necessary.

Clinical experience with extra-intracranial arterial anastomosis in 65 cases.

Clinical results of an extra-intracranial arterial bypass (EIAB) procedure for cerebral ischemia are assessed in 65 patients. The 5-year-study suggests that the EIAB procedure has a protective effect against further clinically significant cerebrovascular accidents in properly selected patients. Correlation with angiography and regional cerebral blood flow (rCBF) studies are discussed. It is felt that rCBF measurements offer the best diagnostic test to determine which patients are suitable for surgery by revealing if an ischemic or relative ischemic focus is present. The surgical procedure is contraindicated in acute cerebral ischemia and when the rCBF study reveals general reduction of cerebral blood flow as opposed to a localized ischemic focus.