[Indications for using an intraluminal temporary bypass in operations on carotid arteries]

The review is dedicated to the most commonly used method of protecting the brain in carotid endarterectomy, i. e. using an intraluminal temporary bypass (ITB), also containing the information concerning the constructions of ITBs, various points of view regarding practical application thereof, as well as the methods of monitoring the functions of the brain in order to solve the problem concerning feasibility of using an ITB.

Mechanical Thrombectomy for Acute Ischemic Stroke

Background and Purpose— Mechanical thrombectomy is a promising new modality of interventional stroke treatment. The various devices differ with regard to where they apply force on the thrombus, taking a proximal approach such as aspiration devices or a distal approach such as basket-like devices. The study compares the in vivo effectiveness and thrombus–device interaction of these 2 approaches.

Methods— Angiography and embolization with a radioopaque whole blood thrombus was performed in 10 swine. Mechanical thrombectomy was performed in 20 cranial vessels using a proximal aspiration device (Vasco35) and a distal basket-like device (Catch) with and without proximal balloon occlusion. Fifty-six retrieval attempts were made.

Results— The proximal device allowed fast repeated application with a low risk of thromboembolic events (3%) and vasospasm, but it had a significantly lower success rate (39.4%) in retrieving thrombotic material than the distal device (DD) (82.6%; odds ratio, 7.3; 95% CI, 2.0 to 26.4). The compaction of the thrombus during retrieval with DD increased the risk of vessel wall irritation significantly ( P <0.01) and complicated retrieval into the guiding catheter. The number of embolic events was significantly higher with DD (26%; odds ratio, 11.3; 95% CI, 1.35 to 101.6) unless proximal balloon occlusion was used.

Conclusions— The proximal and the distal approaches to mechanical thrombectomy proved to be effective at achieving recanalization of cranial vessels. The proximal device is faster in application and allowed repeated attempts with a low complication rate. The DD is more successful at removing thrombotic material, but its method of application and attendant thrombus compaction increase the risk of thromboembolic events and vasospasms.

Multiple bur hole surgery for the treatment of moyamoya disease in children

OBJECT

The authors' aim in this study was to review their experience in the use of indirect revascularization alone in a series of 14 children with moyamoya disease, in which numerous bur holes and arachnoid openings were made over each affected hemisphere.

METHODS

Revascularization through multiple bur holes and arachnoid openings was performed in 14 children (mean age at diagnosis 6.5 years [range 3-15 years]) who suffered from progressive moyamoya disease. The authors performed surgery in a total of 24 hemispheres during 18 procedures. Ten children underwent bilateral multiple bur hole procedures, three underwent a unilateral procedure in the more severely affected hemisphere, and one child had previously undergone an encephaloduroarteriomyosynangiosis on the contralateral side. Ten to 24 bur holes were made in the frontotemporoparietooccipital area of each hemisphere, depending on the site and extent of the disease. Early postoperative perfusion magnetic resonance imaging studies, performed in the five most recent cases, showed restoration of cortical perfusion as early as 3 months, which was confirmed on subsequent angiography studies (performed between 8 and 12 months postoperatively) that showed excellent revascularization of the ischemic brain by external carotid artery collateral vessels. None of the children sustained further ischemic attacks postoperatively. Motor improvement was noted in those who had presented with paresis. A single seizure episode occurred in two patients at 2 weeks and 5 months after surgery; both children had presented with epilepsy. There were no postoperative deaths, and only one complication (an infected lumbar shunt in the patient who required cerebrospinal fluid [CSF] drainage). Five of the 18 procedures were complicated by subcutaneous CSF collections, which resolved with tapping and compressive head dressings; a transient lumbar drain was necessary in one case.

CONCLUSIONS

The results obtained in this series suggest that in children with moyamoya disease this simple technique is both effective and safe. Furthermore, it is effective as a sole treatment without supplementary revascularization procedures.

Carotid angioplasty and stenting: caveat emptor!

Carotid endarterectomy effectively reduces stroke in patients with TIA or minor stroke and a high-grade carotid stenosis. Carotid endarterectomy is also beneficial in male asymptomatic patients younger than 75 years with high-grade stenosis. Carotid stenting has not been as thoroughly evaluated as carotid endarterectomy in randomized trials. The few trials that have been performed up to now show either inferior results or suggest equivalence. Before accepting carotid stenting as a mainstream treatment for carotid stenosis, this therapy should be as critically evaluated as carotid endarterectomy was in the 1980s and 1990s.

Symptomatic non-atherosclerotic bilateral extracranial vertebral artery occlusion treated with extracranial to intracranial bypass: case report

Posterior fossa ischemia is not a very frequent situation. It is responsible for about 25% of all ischemic strokes, and the vast majority of the cases are related to atherosclerotic stenosis of the vertebral and/or basilar arteries. Acute ischemia can also occur in the setting of vertebral artery dissection, traumatic or spontaneous. Recently, blunt trauma has been increasingly recognized as a cause for craniocervical artery injury. The management options for both traumatic and atherosclerotic lesions of the posterior fossa are still under debate. We present a case of a delayed onset of hemodynamic ischemic symptoms due to bilateral vertebral artery occlusion probably related to remote trauma to the head and neck in a 55-year-old-man treated successfully with extracranial to intracranial bypass.

Granulocyte-colony-stimulating factor mobilizes bone marrow stem cells in patients with subacute ischemic stroke: the Stem cell Trial of recovery EnhanceMent after Stroke (STEMS) pilot randomized, controlled trial (ISRCTN 16784092)

BACKGROUND AND PURPOSE

Loss of motor function is common after stroke and leads to significant chronic disability. Stem cells are capable of self-renewal and of differentiating into multiple cell types, including neurones, glia, and vascular cells. We assessed the safety of granulocyte-colony-stimulating factor (G-CSF) after stroke and its effect on circulating CD34+ stem cells.

METHODS

We performed a 2-center, dose-escalation, double-blind, randomized, placebo-controlled pilot trial (ISRCTN 16784092) of G-CSF (6 blocks of 1 to 10 microg/kg SC, 1 or 5 daily doses) in 36 patients with recent ischemic stroke. Circulating CD34+ stem cells were measured by flow cytometry; blood counts and measures of safety and functional outcome were also monitored. All measures were made blinded to treatment.

RESULTS

Thirty-six patients, whose mean+/-SD age was 76+/-8 years and of whom 50% were male, were recruited. G-CSF (5 days of 10 microg/kg) increased CD34+ count in a dose-dependent manner, from 2.5 to 37.7 at day 5 (area under curve, P=0.005). A dose-dependent rise in white cell count (P<0.001) was also seen. There was no difference between treatment groups in the number of patients with serious adverse events: G-CSF, 7/24 (29%) versus placebo 3/12 (25%), or in their dependence (modified Rankin Scale, median 4, interquartile range, 3 to 5) at 90 days.

CONCLUSIONS

G-CSF is effective at mobilizing bone marrow CD34+ stem cells in patients with recent ischemic stroke. Administration is feasible and appears to be safe and well tolerated. The fate of mobilized cells and their effect on functional outcome remain to be determined.

Vascular fate of adipose tissue-derived adult stromal cells in the ischemic murine brain: A combined imaging-histological study

Increasing evidence indicates that fat tissue can provide a novel source of progenitor cells with therapeutic potential. Here, the fate of adipose tissue-derived stromal cells (ADSCs) transplanted into the mouse ischemic cortex was monitored in the long term using in vivo imaging, and subsequently characterized. The left middle cerebral artery (MCA) was occluded in C57BL/6J mice equipped with a closed cranial window chronically implanted over the left parietal cortex (n = 20). ADSCs expressing the green fluorescent protein (GFP) (approximately 18 x 10(3) cells in 0.5 microl) were transplanted into the ipsilateral cortex, 24 h after MCA occlusion. GFP+-ADSCs were monitored through the window using confocal fluorescence microscopy to assess their single fate in vivo. Co-localization of GFP with vascular, neuronal, glial or proliferation markers was investigated immunohistochemically. Repeated in vivo imaging revealed that GFP+-ADSCs migrated over 1 week toward the lesion, survived for at least 4 weeks, and exhibited a particular tropism for vessels. About 5% of the transplanted GFP+-ADSCs were scattered in the peri-ischemic area on histological sections. Immunohistochemistry evidenced that perivascular GFP+-ADSCs enfolded CD31-labeled endothelial cells, always outside their basal lamina, and occasionally expressed smooth muscle alpha-actin. Less than 1% GFP and BrdU co-labeling indicated a low proliferation rate of ADSCs. These results demonstrate that cerebral ischemia induces ADSCs survival, migration toward the lesion, especially toward microvessels, and occasional differentiation into smooth muscle cells.

p53 potentiates hippocampal neuronal death caused by global ischemia

Although p53 controls cell death after various stresses, its role in neuronal death after brain ischemia is poorly understood. To address this issue, we subjected p53-deficient (p53-/- and p53+/-) mice (backcrossed for 12 generations with C57BL/6 mice) and wild-type mice (p53+/+) to transient global ischemia by the three-vessel occlusion method. Despite similar severity of ischemia, as shown by anoxic depolarization and cortical blood flow, neuronal death in the hippocampal cornus ammonis (CA)1 region was much more extensive in p53+/+ than in p53-/- mice (surviving neuronal count, 9.3%+/-3.0% versus 61.3%+/-34.0% of nonischemic p53+/+ controls, respectively, P<0.0037). In p53+/- mice, a similar trend was also observed, though not statistically significant (43.5% of nonischemic p53+/+ controls). In p53+/+ mice, p53-like immunoreactivity in hippocampal CA1 neurons was enhanced at 12 h after ischemia, and messenger ribonucleic acid for Bax, a direct downstream target of p53, was also increased. These results indicate that p53 potentiates ischemic neuronal death in vivo and suggest that this molecule could be a therapeutic target in neuronal death after cerebral ischemia.

Hemichorea due to hemodynamic ischemia associated with extracranial carotid artery stenosis. Report of two cases

In this paper the authors describe two patients with recurrent hemiparesis and limb shaking that gradually progressed to hemichorea. Cerebral angiography confirmed severe unilateral internal carotid artery stenosis (95%) contralateral to the hemichorea. The cerebral blood flow, assessed using N-isopropyl-p-(iodine-123) iodoamphetamine single-photon emission computed tomography (SPECT), disclosed markedly decreased vascular reserves in both patients. After carotid endarterectomy was performed, the hemichorea gradually subsided and SPECT confirmed increased cerebral perfusion. The results in these cases indicate that surgical revascularization is effective for hemichorea due to cerebral ischemia with reduced vascular reserve.

Stepwise revascularization for prevention of postoperative hyperperfusion

Abrupt normalization of cerebral blood flow (CBF) after surgical procedures to improve excessive cerebral hypoperfusion can cause irreversible brain parenchymal damage. Such hyperperfusion, which is caused by inflow at normal blood pressure into maximally dilated fine vessels, is an important complication following carotid endarterectomy (CEA). Strict control of blood pressure in the perioperative period can prevent this complication except in a few patients, who have severe cerebral hypoperfusion and poor cerebrovascular reserve due to extremely severe stenosis of the ipsilateral or the bilateral carotid arteries, for which CEA is indicated. The requirement for improved CBF and the risk of postoperative hyperperfusion conflict in the pathogenesis of these patients. We tried to prevent abrupt improvement in perfusion by attempting gradual restoration of CBF. Superficial temporal artery-middle cerebral artery anastomosis was first performed to improve the poor cerebrovascular reserve by allowing insufficient blood flow. A few weeks later, CEA was performed to completely restore CBF. This surgical approach obtained good results without postoperative problems in four patients. The indications of this surgical management and efficacy of stepwise restoration of CBF to prevent postoperative hyperperfusion depend on careful preoperative evaluation of perfusion studies.

Early Carotid Endarterectomy after Ischemic Stroke: The Results of a Prospective Multicenter Italian Study

OBJECTIVES

To evaluate safety of early carotid endarterectomy (CEA) in patients with acute brain ischemia presenting to the emergency department stroke units (EDSU).

METHODS

The neurologists, neuroradiologists and vascular surgeons on duty in emergency departments enrolled 96 patients who underwent very early CEA according to a predefined protocol within two years. The protocol included evaluation of neurological status by National Institute of Health Stroke Scale (NIHSS), neuroimaging assessment, ultrasound of the carotid arteries and Transcranial Doppler. Patients with NIHSS>22 or whose neuroimaging showed brain infarct >2/3 of the middle cerebral artery territory were excluded. All eligible patients underwent CEA as soon as possible. Primary end points of the study were mortality, neurological morbidity by NIHSS and postoperative hemorrhagic conversion on neuroimaging. Statistical analysis was performed by univariate analysis.

RESULTS

The mean time elapsing between the onset of stroke and endarterectomy was 1.5 days (+/-2 days). The overall 30-day morbidity mortality rate was 7.3% (7/96). No neurological mortality occurred. On hospital discharge, three patients (3%) experienced worsening of the neurological deficit (NIHSS score 1 to 2, 1 to 3 and 9 to 10 respectively). Postoperative CT demonstrated there were no new cerebral infarcts nor hemorrhagic transformation. At hospital discharge 9/96 patients (9%) had no improvement in NHISS scores, 37 were asymptomatic and 45 showed a median decrease of 4.5 NIHSS points (range 1-18). By univariate analysis none of the considered variables influenced the clinical outcome.

CONCLUSION

Our protocol selected patients who can safely undergo very early (<1.5 days) surgery after acute brain ischemia. Large randomized multicenter prospective trials are warranted to compare very early CEA versus best medical therapy.

Administration of Ex Vivo-expanded Bone Marrow-derived Endothelial Progenitor Cells Attenuates Focal Cerebral Ischemia-reperfusion Injury in Rats

OBJECTIVE

This study aimed to examine early effects of ex vivo-expanded bone marrow-derived endothelial progenitor cells (EPCs) on focal cerebral ischemia-reperfusion injury.

METHODS

EPCs were obtained from mononuclear cells of autologous bone marrow of a rat. After culture on fibronectin-coated dishes for 10 to 14 days, 2.5 x 10 cells of EPCs were administered transarterially after 90 minute occlusion of the middle cerebral artery.

RESULTS

Administration of EPCs significantly reduced both the infarct volume and the scores of neurological deficits at 24 and 48 hours. EPCs administered 2 hours after insult did not reduce infarct volume, but attenuated neurological deficits at 24 hours. Administration of EPCs significantly reduced the number of myeloperoxidase-immunoreactive cells in the ischemic lesion at 24 hours and increased regional cortical blood flow at 48 hours. EPCs were observed in the ischemic hemisphere and around the endothelial layer of the pial arteries. Most of them expressed endothelial nitric oxide synthase.

CONCLUSION

Administration of ex vivo-expanded bone marrow-derived EPCs reduced infarct volume and neurological deficits in acute focal brain ischemia-reperfusion injury caused, at least in part, by attenuation of endothelial dysfunction.

Neuroprotection by PlGF gene-modified human mesenchymal stem cells after cerebral ischaemia

Intravenous delivery of mesenchymal stem cells (MSCs) prepared from adult bone marrow reduces infarction size and ameliorates functional deficits in rat cerebral ischaemia models. Placental growth factor (PlGF) is angiogenic to impaired non-neural tissue. To test the hypothesis that PlGF contributes to the therapeutic benefits of MSC delivery in cerebral ischaemia, we compared the efficacy of systemic delivery of human MSCs (hMSCs) and hMSCs transfected with a fibre-mutant F/RGD adenovirus vector with a PlGF gene (PlGF-hMSCs). A permanent middle cerebral artery occlusion (MCAO) was induced by intraluminal vascular occlusion with a microfilament. hMSCs and PlGF-hMSCs were intravenously injected into the rats 3 h after MCAO. Lesion size was assessed at 3 and 6 h, and 1, 3, 4 and 7 days using MR imaging and histology. Functional outcome was assessed using the limb placement test and the treadmill stress test. Both hMSCs and PlGF-hMSCs reduced lesion volume, induced angiogenesis and elicited functional improvement compared with the control sham group, but the effect was greater in the PlGF-hMSC group. Enzyme-linked immunosorbent assay of the infarcted hemisphere revealed an increase in PlGF in both hMSC groups, but a greater increase in the PlGF-hMSC group. These data support the hypothesis that PlGF contributes to neuroprotection and angiogenesis in cerebral ischaemia, and cellular delivery of PlGF to the brain can be achieved by intravenous delivery of hMSCs.

Magnetic resonance angiography and clinical evaluation of third nerve palsies and posterior communicating artery aneurysms

Object

The authors conducted a study to determine the utility of the clinical profile and magnetic resonance (MR) angiography in evaluating patients with isolated third cranial nerve palsies or posterior communicating artery (PCoA) aneurysms.

Methods

Three-dimensional time-of-flight MR angiography was performed in a consecutive series of patients with isolated acute third cranial nerve palsy not due to a ruptured aneurysm and in patients with unruptured PCoA aneurysms. A neuroradiologist, masked to the identities of the patients, interpreted reformatted maximum intensity projection (MIP) and source images of the PCoAs and aneurysms. The investigators assessed clinical features of oculomotor nerve dysfunction and focal head pain. Cases involving cranial third nerve palsy without aneurysms were classified as Group 1 (no case entailed catheter-based angiography), and cases involving PCoA aneurysms seen on MR angiography (42 cases confirmed by catheter-based angiography) were classified as Group 2.

The mean age of the 73 patients in Group 1 was 60.1 years and that of the 45 patients in Group 2 was 59.1 years (p = 0.37). The pattern and severity of oculomotor (p = 0.61) and lid (p = 0.83) dysfunction and pain frequency (p = 0.2) were similar for the 73 patients with vasculopathy in Group 1 and the 15 symptomatic patients in Group 2. Abnormal pupils were observed in 38% of the patients in Group 1 and 80% of those in Group 2 (p = 0.016). In cases of complete external third nerve palsy, nine of 22 in Group 1 and none of four in Group 2 had normal pupil function. For all patients, source imaging showed 206 PCoAs (85%) and MIP imaging demonstrated 120 PCoAs (49%). Of 48 aneurysms (three bilateral), MIP imaging showed 44 (92%) and source imaging showed 47 (98%). Only a 2-mm aneurysm seen on catheter-based angiography was missed by MR angiography. Symptomatic aneurysms were equal or greater than 4 mm in size.

Conclusions

Only the presence of complete external third nerve palsy and normal pupil function allowed ischemia to be clinically distinguished from a PCoA aneurysm in a patient with isolated third nerve palsy and no subarachnoid hemorrhage. When source image MR angiography demonstrates normal findings, catheter-based angiography need not be performed in these patients, even if pupil function is abnormal.

Changes in Brain Volume 2 Years after Extracranial-Intracranial Bypass Surgery: A Preliminary Subanalysis of the Japanese EC-IC Trial

BACKGROUND AND METHODS

We studied changes in brain volume on magnetic resonance imaging in 10 patients with and without extracranial-intracranial (EC-IC) bypass surgery who met the inclusion criteria for the Japanese EC-IC Bypass Trial, a multicenter, randomized, prospective study of patients with hemodynamic brain ischemia due to cerebral artery occlusive disease. We also examined the association of cerebral hemodynamics on single-photon emission computed tomography with the changes in brain volume.

RESULTS

The affected/unaffected ratio of the percent brain volume declined in patients without EC-IC bypass surgery (p < 0.02, n = 4), and the affected/unaffected percent regional cerebral blood flow ratio increased in patients with the surgery (p < 0.03, n = 6). Acetazolamide reactivity increased in the affected hemisphere of patients with surgery (p < 0.01). Two-year increase (decrease) in acetazolamide reactivity of the affected hemisphere showed a significant positive correlation with 2-year changes in the affected/unaffected percent brain volume ratio (R2 = 0.737, p = 0.0007).

CONCLUSIONS

Change in acetazolamide reactivity might be a good predictor for brain atrophy in cerebral artery occlusive disease.

Cerebral hyperperfusion after carotid endarterectomy is associated with preoperative hemodynamic impairment and intraoperative cerebral ischemia

The aim of this study was to investigate whether postoperative hyperperfusion is associated with preoperative cerebral hemodynamic impairment due to chronic ischemia and with acute cerebral ischemia during clamping of the internal carotid artery (ICA) during carotid endarterectomy (CEA). Transcranial cerebral oxygen saturation (SO2) was monitored intraoperatively using near-infrared spectroscopy in 89 patients undergoing CEA for ipsilateral ICA stenosis (>70%). Cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) to acetazolamide were also measured using single photon emission computed tomography (SPECT) before CEA. In addition, CBF was measured immediately after CEA and on the third postoperative day. Hyperperfusion (CBF increase>100% compared with preoperative values) was observed immediately after CEA in 10 of 18 patients (56%) with reduced preoperative CVR. Also, post-CEA hyperperfusion was observed in nine of 16 patients (56%) whose SO2 during clamping of the ICA decreased to less than 90% of the preclamping value. Logistic regression analysis showed that reduced preoperative CVR and reduced SO2 during ICA clamping were significant independent predictors of the development of hyperperfusion immediately after CEA. In fact, all patients with reduced preoperative CVR and reduced SO2 during ICA clamping developed post-CEA hyperperfusion, and two of these patients developed cerebral hyperperfusion syndrome. These data suggest that development of cerebral hyperperfusion after CEA is associated with preoperative hemodynamic impairment and intraoperative cerebral ischemia.

[Surgical treatment of the brain ischemic disease]

There were examined 825 patients, in whom affection of extracranial arteries was revealed, including 340 (41.2%) men and 485 (58.8%) women, 27 to 73 years old. Atherosclerotic stenosis and occlusion of extracranial arteries was diagnosed in 305 (40.0%), pathologic kinking of vessels on atherosclerosis and hypertonic disease background--in 196 (23.8%), pathological kinking, caused by aortoarteriitis and fibrose--muscular displasia--in 197 (23.9%), hypoplasia of arteries--in 54 (6.5%), aortoarteriitis--in 73 (8.8%) patients. Stages I-IV ischemia together with proven affection of extracranial arteries served as indication for surgical treatment of chronic cerebro-vascular insufficiency. Depending on character of the arteries affection 11 kinds of operative interventions were conducted, using complex intraoperative program of the brain defense. Total number of reconstructive operations performed was 967. In 752 (91.2%) patients immediate good and satisfactory results were noted. In the late period 450 patients were examined: good results were achieved in 64.9%, satisfactory--in 22%, in 30 (6.7%) improvement did not occur and 28 (6.2%) died. Introduction of the proposed complex examination and surgical treatment program have permitted to improve the results of treatment of the patients, suffering chronic brain ischemia.

Revascularização clínica e intervencionista no acidente vascular cerebral isquêmico agudo: opinião nacional

Este artigo apresenta as conclusões sobre revascularização clínica e intervencionista no acidente vascular cerebral isquêmico agudo, um dos temas discutidos na reunião "Opinião Nacional sobre o Tratamento do AVC". Tratou-se de reunião promovida e coordenada pela Sociedade Brasileira de Doenças Cerebrovasculares, com neurologistas especializados em doenças cerebrovasculares, que analisaram e discutiram as evidências e experiências atuais sobre o uso de trombólise e técnicas intervencionistas em pacientes com acidente vascular cerebral isquêmico agudo.

Cerebral Ischemia as a Presenting Feature of Intracranial Aneurysms: A Negative Prognostic Indicator in the Management of Aneurysms

OBJECTIVE

Cerebral ischemia (stroke) can be a presenting clinical feature of intracranial aneurysms and may herald poor prognosis.

METHODS

A retrospective review of admissions for aneurysms over a 6-year period revealed that 12 patients (5%) had stroke or stroke-like presentations among 236 patients with intracranial aneurysms. Patient demographics, characteristics of aneurysms, and management were analyzed.

RESULTS

Of 12 patients reviewed, nine had anterior circulation aneurysms. Two patients presented with subarachnoid hemorrhage and 10 with unruptured aneurysms. Eleven patients had stroke at the time of presentation, and five had a previous history of transient ischemic attacks. Ten patients had hypertension and eight were active smokers. The mean size of 10 aneurysms was 11.8 mm. Surgical extirpation of the aneurysms was performed in all cases. Four cases revealed thrombus in the aneurysm and one was atherosclerotic. The 6-month outcome was good in seven patients (58%) and fair in four patients (33%). One patient died. This outcome was significantly worse (P < 0.01) compared to that of good grade aneurysms in our database. Hypertension was a significant indicator of poor outcome (P < 0.02).

CONCLUSION

Ischemic episodes as a presenting feature of intracranial aneurysms could be indicators of poor prognosis. Routine evaluation of stroke patients for aneurysms may help in early diagnosis. In addition, surgical obliteration of aneurysms could prevent subsequent strokes and neurological deficits.

Cerebral blood oxygenation changes induced by bypass blood flow in moyamoya disease and non-moyamoya cerebral ischaemic disease

BACKGROUND

Superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis has been used to prevent stroke in patients with moyamoya disease (MD) and non-moyamoya ischaemic disease (non-MD). However, little is yet known regarding the difference between these groups of patients in the extent to which the bypass contributes to maintaining adequate cerebral blood oxygenation (CBO), or the temporal changes after surgery. In the present study, we evaluated the CBO changes induced by bypass blood flow in patients with MD and non-MD during the peri-operative periods employing optical spectroscopy.

METHODS

We investigated 13 patients who underwent STA-MCA anastomosis, including 5 MD and 8 non-MD patients. We evaluated the effects of STA blood flow on the CBO in the MCA territory on the anastomosis side, employing visual light spectroscopy during surgery and near infrared spectroscopy (NIRS) at one week after surgery.

FINDINGS

In 4 MD patients and one non-MD patient, the STA blood flow increased the oxyhaemoglobin and cortical oxygen saturation (CoSO2), indicating that the bypass supplied blood flow to the ischaemic brain; the CBO changes were observed more frequently in MD than in non-MD patients (p<0.02). The pre-anastomosis CoSO2 (65.4+/-5.4%) in MD was significantly lower than that (72.8+/-7.6%) in non-MD (p<0.05). Postoperative NIRS demonstrated that the bypass began to supply blood flow to the brain in 5 non-MD patients whose bypass did not supply blood flow during surgery.

CONCLUSIONS

Although MD has vessels of small diameter as compared to non-MD, the bypass begins to supply blood flow to the ischaemic brain earlier in MD than in non-MD after anastomosis. The fact that the CoSO2 in MD was lower than that in non-MD suggested that the perfusion pressure in MD was lower than that in non-MD, and this might account for the difference in the bypass blood supply after anastomosis between MD and non-MD. Our data suggest that, even if the bypass does not supply blood to the brain during surgery in non-MD, the bypass blood flow gradually increases after surgery.

Prospective study of symptomatic atherothrombotic intracranial stenoses: The GESICA Study

BACKGROUND

Symptomatic intracranial atherothrombotic stenoses (ICAS) are associated with high rates of cerebrovascular ischemic events.

OBJECTIVE

To conduct a prospective multicenter study to evaluate the natural history of ICAS and, in those patients refractory to medical treatment, the outcomes associated with intracranial angioplasty.

METHODS

Patients aged 18 to 80 were enrolled with symptoms attributed to a single ICAS of > or =50%. Optimal medical therapy of vascular risk factors and preventive antithrombotic therapy were at the discretion of the local investigator. Patients were eligible for intracranial angioplasty after experiencing recurrent stroke despite medical therapy. Neurologic and ultrasonographic examinations were performed at study inclusion, 3 months after enrollment, and every 6 months of follow-up thereafter, for 36 months.

RESULTS

One hundred two patients were included, with a mean age of 63.3 +/- 10.4 years. Intracranial artery stenoses involved the vertebral artery in 22.5%, the basilar artery in 25.5%, the middle cerebral artery in 26.5%, and the internal carotid artery in 25.5%. In 27.4% of the patients, the stenoses had clinical hemodynamic characteristics. During a mean follow-up of 23.4 months, 38.2% of the patients had a cerebrovascular event: ischemic stroke in 13.7% and TIA in 24.5%. Among patients with a hemodynamically significant stenosis, 60.7% had a recurrent stroke or TIA in the territory of the stenotic artery; this association was significant in univariate analysis. Twenty-eight patients underwent an endovascular procedure with a neurologic periprocedural complication rate of 14.2%. The overall vascular death rate was 8.8%.

CONCLUSIONS

Despite medical treatment, the 2-year recurrence rate of ischemic events in the territory of the stenotic artery was 38.2%. Cardiovascular events occurred in 18.6% of patients. Clinically significant hemodynamic stenoses were associated with stroke recurrence and may help identify a high risk subset of patients.