Showing papers on "Cerebral Revascularization published in 2007"

Deep hypothermic circulatory arrest for complex cerebral aneurysms: Lessons learned

Abstract: OBJECTIVE Deep hypothermic circulatory arrest is a useful adjunct for treating complex aneurysms. Decreased cerebral metabolism and resultant ischemic tolerance create an environment suitable for devascularizing high-risk lesions. However, the advent of modern imaging modalities, innovative cerebral revascularization strategies, and the emergence of endovascular stenting and coiling limit the number of aneurysms requiring this surgical intervention. We present 66 patients with intracranial aneurysms who underwent surgical clipping under deep hypothermic arrest and attempt to identify patients well-suited for this procedure. METHODS This study was conducted during a 15-year period and examined patients with aneurysms of the anterior and posterior cerebral circulation. Demographics, aneurysm characteristics, and surgical factors were evaluated as predictors of functional outcome. RESULTS Patient age and the duration of cardiac arrest were independent predictors of early clinical outcome (P < 0.05). Our experience suggests that the ideal patient is younger than 60 years old and harbors few medical comorbidities. Individuals with large aneurysms of the anterior communicating artery, internal carotid artery bifurcation, posterior inferior cerebellar artery, midbasilar, or vertebral arteries and with an absence of thrombosis and calcium may be most likely to experience favorable outcomes. Circulatory arrest should not exceed 30 minutes. Postoperative computed tomographic scanning and timely anesthetic emergence allow for early detection of hemorrhage. Complete dissection of the aneurysm before bypass and avoiding extreme hypothermia yield a low incidence of life-threatening postoperative hematomas. CONCLUSION Hypothermic circulatory arrest is a useful technique for neuroprotection during the clipping of complex cerebral aneurysms. This procedure, however, has several associated risks. Patient factors, pathoanatomic characteristics, and surgical parameters may be used to guide patient selection.

Complete occlusion of extracranial internal carotid artery: clinical features, pathophysiology, diagnosis and management

Abstract: A complete occlusion of the internal carotid artery (ICA) is an important cause of cerebrovascular disease. A never-symptomatic ICA occlusion has a relatively benign course, whereas symptomatic occlusion increases future risk of strokes. Ultrasonography, magnetic resonance imaging and contrast angiography are useful diagnostic tests, and functional imaging of the brain (eg, with positron emission tomography) helps to understand haemodynamic factors involved in the pathophysiology of brain ischaemia. Recently, there has been a resurgence of interest in the role of extracranial-intracranial bypass surgery for the treatment of completely occluded ICA. With advances in the measurement of cerebral haemodynamics, it may be possible to identify high-risk patients who could benefit from the bypass surgery.

Symptomatic hyperperfusion after superficial temporal artery–middle cerebral artery anastomosis in a child with moyamoya disease

Abstract: Surgical revascularization for moyamoya disease prevents cerebral ischemic attacks by improving cerebral blood flow (CBF). It is undetermined, however, how rapid increase in CBF affects ischemic brain at acute stage, especially in children. A 4-year-old girl with moyamoya disease underwent right superficial temporal artery–middle cerebral artery (STA–MCA) anastomosis. She suffered temporary left facial palsy 5 days after surgery. Postoperative N-isopropyl-p-[123I]iodoamphetamine single-photon emission computed tomography (123I-IMP-SPECT) revealed focal intense increase in CBF at the sites of anastomosis. Magnetic resonance imaging/angiography showed the apparently patent STA–MCA anastomosis as a thick high signal without ischemic changes. Her symptom improved 9 days after surgery, and single-photon emission computed tomography (SPECT) 2 months later showed normalization of CBF. Surgical revascularization completely relieved the transient ischemic attack on her left hand that was seen before surgery. We demonstrated, for the first time, that delayed focal neurological deficit after STA–MCA anastomosis can be caused by focal hyperperfusion in childhood moyamoya disease.

Emergency revascularization for acute main-trunk occlusion in the anterior circulation

Abstract: We report the surgical results in patients with acute cerebral main-trunk occlusion in the anterior circulation. Between April 2004 and March 2005, 26 patients were surgically treated within 24h after the onset. The occlusion occurred in the internal carotid artery in 10 patients, in the middle cerebral artery in 15, and in the anterior cerebral artery in 1. We investigated the clinical characteristics and surgical treatment and evaluated the outcome using the modified Rankin Scale (mRS). Nine patients underwent anastomosis, 14 had an embolectomy, and 3 had a carotid endarterectomy. In all the patients, revascularization was achieved, and neurological improvement was obtained. At 6months after the onset, eight (30.8%) patients showed a good recovery (defined as grade 1 on the mRS), seven (26.9%) were rated as grade 2, eight (30.8%) were grade 3, and three (11.5%) were grade 4. Manual muscle test on admission was significantly different between the good outcome and the poor outcome groups at 6months after onset. None of the patients experienced any complications related to the surgery. Early surgical revascularization can be an effective and safe treatment modality in appropriately selected patients with acute cerebral main-trunk occlusion in the anterior circulation.

Rapid intracranial clot removal with a new device: the alligator retriever.

Abstract: BACKGROUND AND PURPOSE: Despite availability of an approved drug to treat acute cerebral ischemia, most patients with stroke do not realize a good outcome. A method that would rapidly increase or restore cerebral perfusion before irreversible cell death should improve patient outcomes. MATERIALS AND METHODS: We recently had the opportunity to treat 6 middle-aged-to-elderly patients who presented with signs and symptoms of acute cerebral ischemia, by mechanically removing their (predominantly) middle cerebral artery clots by using a new retrieval device that had been previously approved by the US Food and Drug Administration for intravascular retrieval of foreign bodies. During a 2-month period, the 6 patients were treated in 5 separate institutions. No patient had an unsuccessful attempt at clot removal. The cases were collected by personal communication with each operator. RESULTS: In all instances, use of the device resulted in rapid clot removal. Each patient had a large improvement in National Institutes of Health Stroke Scale score. Two of the 6 patients had experienced failure of another clot retrieval device, and 3 patients required no systemic thrombolytics, reducing the likelihood of one of the most feared complications of stroke therapy, intracranial hemorrhage. SUMMARY: We believe that use of this device may result in improved outcomes for patients with acute ischemic stroke. In our limited experience, it provided a rapid, safe, and effective means for achieving revascularization.

Extracranial-intracranial bypass surgery to reduce the risk of haemodynamic stroke in cerebroocclusive atherosclerotic disease of the anterior cerebral circulation - a systematic review.

Abstract: Background and purpose Selected patients with acute or continual ischaemic symptoms from occlusions or inaccessible stenotic lesions of the internal carotid artery or middle cerebral artery have been considered candidates for an extracranial-intracranial (EC-IC) bypass procedure. Hitherto, no effectiveness of this surgical therapeutic option for various patient subgroups could be found in a large international randomized trial, and therefore various guidelines give negative recommendations for its usefulness. The aim of the present report was to analyze clinical effectiveness of EC-IC bypass for cerebral revascularization in haemodynamic subgroups of patients with advanced occlusive cerebrovascular disease in the anterior cerebral circulation. Material and methods A computerized database search from November 1985 to November 2001 was performed. Language restriction was done for English, French and German. Reports dealing with EC-IC bypass surgery for cerebral revascularization in case of advanced cerebrovascular disease in the anterior cerebral circulation were reviewed when appropriate. Studies were included if they contained valuable data on clinical state, pre- and postoperative haemodynamic state, surgical outcome and follow-up. Results The postoperative outcome related to death or stroke depended mainly on preoperative haemodynamic subgroups (CBF/CBV; OEF). The final functional status was worse the more the CBF/CBV ratio and OEF increased. Perioperative risk for death (0.6%) or stroke (2%) during the first month after surgery was similar to the death or stroke rate during the following 2 to 12 months after surgery. The overall risk profile for subsequent death or stroke of surgically treated patients is significantly better within the first 12 months than that of conservatively treated patients (1.3% vs. 3.6% per year). Neurological function was improved over the preoperative state in 84% of the patients and was unchanged in 6%. Postoperatively, modified Rankin scale score was 0-1 in 90% of patients and 2 in 1% of patients. Long-term patency was excellent, with 1% failure rate per year following the first year after surgery. Conclusion Neurological function and subsequent stroke attributable to haemodynamic insufficiency in patients with symptomatic carotid occlusion or severe stenosis are improved significantly by EC-IC bypass surgery if the brain area corresponding to the impaired neurological function remains viable. The haemodynamic parameters observed for patients who experience improved neurological function or diminished stroke risk profile after EC-IC-bypass surgery contain both significantly elevated OEF and CBF/CBV. Therefore haemodynamic profile represents an important indicator for EC-IC bypass surgery and gives a good rationale for new trials conducted in a subgroup of patients selected on the basis of their haemodynamic profile.

Long term evaluation of brain perfusion with magnetic resonance in high flow extracranial-intracranial saphenous graft bypass.

Abstract: Assessment was made of the cerebral vascular haemodynamic parameters in patients with a high-flow extra-intracranial (EC-IC) bypass performed for therapeutic occlusion of the internal carotid artery (ICA). Sixteen patients with ICA occlusion and EC-IC bypass (time interval from surgery 1–6 years) underwent MRI. Perfusion-weighted magnetic resonance imaging (PW-MRI) sequences were performed without the use of an arterial input function. The relative cerebral blood volume (rCBV), mean transit time (MTT) and relative cerebral blood flow (rCBF) were evaluated in all patients at the level of the basal ganglia, centrum semiovale and cortex in both hemispheres. Statistically significant differences (P<0.005) were observed in the haemodynamic parameters, indicating increased rCBV in the basal ganglia and decreased rCBF and rCBV in the cortex of the hemisphere supplied by the graft with respect to the contralateral. Patients with occlusion of the ICA and high flow EC-IC bypass do have altered vascular haemodynamic status between the hemispheres. In particular, rCBF is impaired in the surgical hemisphere at the level of the cortex. These patients should be followed-up to rule out chronic ischemia.

Rapid revascularization after therapeutic parent artery occlusion for a large intracavernous carotid artery aneurysm.

Abstract: A 21-year-old woman presented with an unruptured large intracavernous aneurysm, which was spontaneously revascularized via unusual collateral pathways a short time after extracranial-intracranial bypass and surgical ligation of the proximal internal carotid artery. The patient had been treated for a large basilar trunk aneurysm with intraaneurysmal embolization using Guglielmi detachable coils, and an intracavernous carotid artery aneurysm treated conservatively. Two years later, the patient presented with right abducens nerve palsy, and was referred to our hospital. She had small nevi in the right forehead and eyelid. Cerebral angiography revealed enlargement of the intracavernous aneurysm. Superficial temporal artery-middle cerebral artery bypass followed by surgical carotid artery ligation were performed, and good patency of bypass and disappearance of the aneurysm were confirmed by intraoperative angiography. However, follow-up magnetic resonance angiography and cerebral angiography on the 20th postoperative day revealed revascularization of the internal carotid artery and the intracavernous carotid artery aneurysm via unusual collateral pathways. Subsequently, the recurrent aneurysm and the recanalized internal carotid artery were occluded by endovascular procedures. Histological examination of the nevus showed lack of properly organized vascular structures, and the diagnosis was angiodysplasia. The early development of unusual collateral pathway, and aneurysm formation at a young age might be related to the angiodysplasia. Revascularization is possible within a short time even in cases of intracavernous carotid artery aneurysm successfully treated with surgical ligation of the parent artery.

Treatment of carotid artery disease: stenting or surgery.

Abstract: Carotid endarterectomy (CEA) is the only form of cerebral revascularization for which Level 1 evidence of effectiveness has been reported. Recent studies demonstrate the feasibility of carotid artery stenting (CAS) as an alternative to CEA. Its popularity is due to the perceived advantages of a less invasive treatment for carotid occlusive disease. Two randomized trials have reported no difference in the composite stroke, death, and myocardial infarction rate between CAS and CEA. However, these trials were not powered to identify superiority between the two procedures. A trial sponsored by the National Institutes of Health is currently underway to make that determination. The lead-in phase of this trial noted low complication rates with CAS. These results have encouraged the US Food and Drug Administration to approve the use of CAS in patients with neurologic symptoms (ie, ipsilateral stroke, transient ischemic attacks, and amaurosis fugax) in association with severe medical co-morbidities. Patients with carotid restenosis after previous CEA, anatomically inaccessible lesions above C2, and radiation-induced stenoses may also benefit from preferential treatment with CAS. The National Institutes of Health have now expanded the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST) to include asymptomatic patients, and resulting data will help to clarify the role of CAS in this subset as well.

Multimodale Therapie zerebraler Aneurysmen. Klinische, technische und angiographische Kriterien in der Entscheidungsfindung

Abstract: Multimodality Treatment of Cerebral Aneurysms. Several therapeutic options are available for the treatment of intracranial aneurysms. Among these, reconstructive procedures allow for selective obliteration of the aneurysm without compromising parent artery patency. Selective aneurysm occlusion can be achieved by either microsurgical clipping or endosaccular coil embolization. In anatomically feasible lesions, coils can be deployed inside the aneurysm sac without adjunctive measures, whereas in broad-necked, anatomically unfeasible aneurysms, coil protrusion into the parent artery can be avoided by the use of so-called neck-bridging devices. In contradistinction, deconstructive procedures achieve permanent aneurysm obliteration by therapeutic proximal occlusion of the parent artery and the aneurysm itself. Among the deconstructive techniques, proximal artery occlusion without bypass protection, proximal artery occlusion following a cerebral revascularization procedure, and so-called flow modification techniques are available. Reconstructive and deconstructive therapeutic measures as outlined in this manuscript should be available at centers involved in the treatment of intracranial aneurysms. Multimodality treatment by combined microsurgical and endovascular approaches allow for the safe management of difficult aneurysms with low procedural morbidity rates. J Neurol Neurochir Psychiatr 2007; 8 (3): 16–26.

Surgery of the pretransversal vertebral artery: indications and results.

Abstract: Aim. The aim of this study was to evaluate our results with elective vertebral arteries surgery, to emphasize the indications of such revascularization and to compare it with previous larger studies. Methods. The medical records of all patients who underwent a pretransversal vertebral artery (VA) revascularization between 1990 and 2004 at our University Hospital were retrospectively reviewed. Results. Forty patients, with a mean age of 60.5 years, met the criteria for VA surgery and accounted for 4.2% of the vascular surgeries involving the brain. Seventeen (42.5%) patients presented with vertebrobasilar insufficiency of hemodynamic origin, 16 (40%) with embolism, and 7 (17.5%) had no neurological symptoms. Direct vertebrocarotid reimplantation was the main procedure performed. No death or stroke occurred preoperatively or during the perioperative period. Mean follow-up was 31 months. Overall survival was 86.9% at 3 years and the primary patency rate was 97.5% at 3 years. Conclusion. Our study confirms the good results achieved by the pretransversal conventional VA surgery. This surgery remains few in number despite the fact that about 25% of ischemic strokes occur in the vertebrobasilar region. Vertebrobasilar signs should be better recognized to avoid performing this type of procedure merely based on imaging criteria.

Subarachnoid hemorrhage caused by a dissecting carotid artery aneurysm

Abstract: Dissecting aneurysms of the carotid artery as a cause of subarachnoid hemorrhage are rare. However, the association of arterial dissection with the etiology of some aneurysms of the dorsal or anterior wall of the carotid artery, carotid trunk or "blister-like" aneurysms has increased the interest in the description of dissecting aneurysms, as they are difficult to treat and require non-habitual surgical techniques. We present the case of a patient that presented with a poor grade subarachnoid hemorrhage secondary to a right carotid artery dissecting aneurysm characterised in angiography by a carotid artery stenosis accompanied by a post-stenotic dilatation and the finding of a saccular aneurysm that increased in size in the follow-up study. A carotid occlusion test showed an asymmetry in the opacification of the venous phase indicating the need for a revascularization procedure prior to arterial sacrifice. A high flow EC-IC bypass was performed using a saphenous vein graft prior to right carotid artery occlusion without morbidity. Eight months after the procedure the patient is free of neurological deficit. Control image studies demonstrate the resolution of the carotid lesion and the bypass permeability. We discuss the difficulties in the diagnosis of these aneurysms, their clinical and imaging characteristics and the problems related to their treatment as they often require arterial sacrifice with or without prior cerebral revascularization.

A case of spontaneous fusiform aneurysm in a middle cerebral artery branch which causes rapidly thrombosed formation in a short period

Abstract: A 61-year-old man presented with the complaint of headache. Investigations revealed a fusiform middle cerebral artery aneurysm at the M2 part. The formation of the aneurysm rapidly developed to a partially thrombosed aneurysm in the course of four months. As regards the treatment of the aneurysm, at first we tried surgery with a superficial temporal artery middle cerebral artery bypass (STA-MCA bypass) and trapping of the aneurysm. However, during the procedure, it was difficult to control bleeding from the temporal muscle, bone flap, and subdural space. Because of this, we finished the STA-MCA bypass without trapping of the aneurysm and then, four days later, we confirmed bypass patency and treated the aneurysm using endovascular coil embolization. Based on both surgical and interventional investigations in this case and a review of the reported literature, the authors propose that there are two mechanisms causing the middle cerebral artery fusiform aneurysm to develop thrombosed formation rapidly: (i) Peripheral middle cerebral artery branches demand less blood flow than other major trunk arteries. (ii) Bypass flow maintains perfusion to the distal branches. On the other hand, this flow alteration caused by surgical vascular bypass may promote the development of the aneurysm to thrombosed formation. The treatment of a fusiform middle cerebral artery aneurysm at the M2 part is also discussed.

Ns01 is there a resurgence of cerebral revascularization

Abstract: Since the publication in 1985 of the EC-IC bypass study group, which demonstrated failure of EC-IC bypass surgery to reduce stroke rate, there has been a dramatic reduction in the number of EC/IC bypass surgeries performed globally. However there have been ongoing concerns amongst neurosurgeons that the EC-IC bypass operation still has a role, at least in selected groups of patients. These groups include, patients with Moya Moya disease, those requiring arterial sacrifice (particularly when trial occlusion demonstrates symptomatic cerebral ischaemia), and in certain patients with cerebral ischaemia in whom medical management has failed and there is a demonstrable reversible ischaemic deficit. Over the past decade there has been de-skilling of the neurosurgical community in cerebrovascular procedures. Even those neurosurgeons who have maintained a high cerebrovascular case-load rarely perform EC-IC bypass surgeries. The technical demands of the procedure are such that it is difficult to maintain skill proficiency with a low case-load. Nevertheless a few cerebrovascular surgeons at large institutions have recently noted an increase in referral of patients requiring EC-IC bypass. Current multicentre studies are underway to re-evaluate its role. It would seem likely that a modest increase in the demand for this surgery will occur.