Search

We previously reported a patient with cerebral proliferative angiopathy (CPA) who showed cerebral ischemia in resting and acetazolamide-stressed N-isopropyl-p-[ 123 I] iodoamphetamine single-photon emission computed tomography ( 123 I-IMP-SPECT). At onset, the patient was treated conservatively. However, during the 2 years following initial onset, his hemiparesis and aphasia had gradually aggravated and his IQ scores were markedly decreased. MRI revealed progressive vascular proliferation and brain atrophy. 123 I-IMP-SPECT showed more severely impaired cerebral blood flow (CBF) and cerebrovascular reactivity over the affected hemisphere. We performed an indirect revascularization to augment CBF; however, his neurological deficits were not improved and new arteriovenous shunts via extracranial-intracranial bypass were developed, followed by an asymptomatic small intracerebral hemorrhage. There are no reports on CPA patients who have shown cerebral hemorrhage after indirect revascularization. Treatments for CPA are still challenging and controversial. Cases with severe stenosis of the proximal arteries may benefit from indirect revascularization. But indirect bypass should not be indicated for such patients without main arterial stenosis, even if they have persistent ischemia., (Copyright © 2018. Published by Elsevier Inc.)

Background: The interval between the onset of cerebral vessel occlusion and recanalization has been shown to be an independent predictor of poor outcomes. However, endovascular recanalization of symptomatic cerebral vessel occlusion in the subacute period has not been well documented. We investigated the safety and efficacy of subacute recanalization of occluded cerebral vessels in patients with ischemic stroke or transient ischemic attacks (TIAs)., Methods: Between 2014 and 2015, 98 patients were admitted to the emergency room for ischemic stroke or TIA with a small infarct core, which was defined as modest early ischemic change on non-contrast CT or overt diffusion-perfusion mismatch. All patients underwent pre-transfemoral cerebral angiography and post-endovascular treatment. The patients were classified according to acute (onset-to-groin puncture time ≤6 hours) or subacute (onset-to-groin puncture time >6 hours) recanalization. Using propensity score analysis, recipients of acute and subacute recanalization underwent 1:1 matching., Results: Following 1:1 propensity score matching, 32 patients who underwent acute and 32 who underwent subacute intra-arterial thrombolysis were matched. There were no significant differences in National Institutes of Health Stroke Scale at discharge, modified Rankin scale (mRS), the proportion of patients with an mRS value of 0-2, mortality at discharge, intracerebral bleeding, postprocedural infarct extension, newly detected infarction, and hyperintense acute reperfusion marker on follow-up images between the acute and subacute recanalization groups., Conclusions: In selected patients with clinically unstable cerebral artery occlusions, a diffusion-perfusion mismatch and small CT lesions, subacute and acute recanalization has comparable safety and efficacy rates., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Stroke is one of the leading causes of death in the world, but its underlying mechanisms remain unclear. Both conventional protein kinase C (cPKC)γ and ubiquitin C-terminal hydrolase L1 (UCHL1) are neuron-specific proteins. In the models of 1-hr middle cerebral artery occlusion (MCAO)/24-hr reperfusion in mice and 1-hr oxygen-glucose deprivation (OGD)/24-hr reoxygenation in cortical neurons, we found that cPKCγ gene knockout remarkably aggravated ischaemic injuries and simultaneously increased the levels of cleaved (Cl)-caspase-3 and LC3-I proteolysis product LC3-II, and the ratio of TUNEL-positive cells to total neurons. Moreover, cPKCγ gene knockout could increase UCHL1 protein expression via elevating its mRNA level regulated by the nuclear factor κB inhibitor alpha (IκB-α)/nuclear factor κB (NF-κB) pathway in cortical neurons. Both inhibitor and shRNA of UCHL1 significantly reduced the ratio of LC3-II/total LC3, which contributed to neuronal survival after ischaemic stroke, but did not alter the level of Cl-caspase-3. In addition, UCHL1 shRNA reversed the effect of cPKCγ on the phosphorylation levels of mTOR and ERK rather than that of AMPK and GSK-3β. In conclusion, our results suggest that cPKCγ activation alleviates ischaemic injuries of mice and cortical neurons through inhibiting UCHL1 expression, which may negatively regulate autophagy through ERK-mTOR pathway., (© 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Primary neuroprotective properties of new inhibitor of Na⁺/⁺ exchanger (compound RU-1355) were established on the model of 60-min focal ischemia of the left middle cerebral artery followed by 24-h reperfusion in rats. Compound RU-1355 significantly (by 34%) decreased neurological symptoms, reduced (1.67 times) the growth of neuron-specific enolase level in serum, decreased (2.3 times) the size of the necrotic zone, and reduced by 59% (p <0.05) the degree of cerebral edema According to the results of morphometric, immunoassay, and neurological assessments of brain damage, compound RU-1355 is superior on ave- rage by 43.5% (p < 0.05) in comparison to selective NHE1 inhibitor zoniporide.

Rodent models of focal cerebral ischemia that do not require craniotomy have been developed by intraluminal suture middle cerebral artery occlusion (MCAo). Mouse MCAo models have been widely used and extended to genetic studies of cell death or recovery mechanisms. Therefore, we compared surgery-related parameters and techniques between such rats and mice. In rodent MCAo models, has to be considered body temperature during the operative period, as well as the need for the use of a standardized tip in terms of the outer diameter of probes. Induction of focal cerebral ischemia was measured by neurological dysfunction parameters. Our methods could induce stable moderate-severity ischemic brain injury models and histological alteration at 24 hr after MCAo surgery. Moreover approximately 80% (rats) and 85% (mice) survival ratios were shown indicating with model engineering success. Finally, we described and compared major parameters between rats and mice, including probe size, thread insert length, operation and occlusion periods, and differences in the procedures.

The present study retrospectively analyzed the database of the Japanese Registry of Neuroendovascular Therapy 1 and 2 (JR-NET1&2) to determine annual trends, including adverse events and clinical outcomes at 30 days after undergoing neuroendovascular therapy. JR-NET1&2 are surveys that targeted all patients in Japan who underwent neuroendovascular therapy delivered by physicians certified by the Japanese Society of Neuroendovascular Therapy (JSNET) between 2005 and 2009. Medical information about the patients was anonymized and retrospectively registered via a website. Data from 32,608 patients were analyzed. The number of treated patients constantly increased from 5,040 in 2005 to 7,406 in 2009 and the rate of octogenarians increased from 7.0% in 2005 to 10.4% in 2009. The proportion of procedures remained relatively constant, but ratios of angioplasty slightly increased from 32.8% in 2005 to 33.7% in 2009. Procedural complications were associated more frequently with acute stroke (9.6%), ruptured aneurysms (7.4%), intracranial artery disease (ICAD) (5.4%), and arteriovenous malformation (AVM, 5.2%). The number of patients requiring neuroendovascular treatment in Japan is increasing and the outcomes of such therapy are clinically acceptable. Details of each type of treatment will be investigated in sub-analyses of the database.

Cerebral artery bypass surgery makes it possible to improve or replace cerebral circulation by bringing blood flow from extracranial arteries into the cerebral arteries or by creating new flow routes between cerebral arteries. Cerebral artery bypass operations play an important role in the treatment of the rare moyamoya disease causing cerebral artery stenosis and disturbances of the cerebral circulation and in the treatment of cerebral aneurysms that are unamenable to treatment with traditional microsurgical or endovascular techniques. Compared with conservative therapy, bypass surgery does, however, not seem beneficial in the prevention of strokes and hemodynamic disturbances of the cerebral circulation associated with atherosclerotic occlusion of the carotid artery.

Acute ischemic stroke affects 3.3 of 100,000 children per year. The causes of AIS in children can be broadly divided into the following 6 categories: cardiac disese, sickle cell disease, moyamoya, arterial dissection, other arteriopathies, and other causes. Approximately 24% of the cases are classified as idiopathic. Magnetic resonance imaging (MRI) and cerebral angiography play an important role in the determining the causes of an AIS in children. Medical approaches, including anticoagulation, anti-inflammatories, and antiplatelet therapies, surgical revascularization and endovascular approaches may have a role in the management of AIS in children., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background: Although most neurovascular diseases can be treated either by microsurgical or endovascular means, a subset of patients may require a combined approach. Patient transfer from the operating room (OR) to the angiosuite has been a fundamental drawback of this type of approach., Objective: The purpose of this study is to report our clinical experience performing combined surgical and endovascular procedures for neurovascular diseases in the hybrid OR., Methods: 29 patients with neurovascular diseases underwent combined endovascular and surgical procedures in a single session: 16 were scheduled combined treatment and 13 were emergency combined procedures. Of the emergency cases, three were rescue surgeries after endovascular complications. Three patients had ruptured intracranial aneurysms, eight had unruptured intracranial aneurysms, eight had arteriovenous malformations and eight had arteriovenous fistulae; two patients had either a spinal tumor or dural arteriovenous fistulae., Results: All combined procedures were performed in a single session without changing the patient's surgical position. In cases of ruptured arteriovenous malformations or aneurysms with hematoma, an emergency embolization was performed to assist the surgical procedure. Combined superficial temporal artery-middle cerebral artery (STA-MCA) bypass followed by endovascular parent artery trapping were successfully performed for complex large or giant aneurysms. There were two periprocedural ischemic complications. Of the three patients who underwent surgical rescue after endovascular complications, two remained intact and one died despite immediate surgical procedures., Conclusion: A combined endovascular and surgical approach conducted in a hybrid OR provides a new strategy for the treatment of complex neurovascular diseases.

Albeit no direct anatomical information can be obtained, neurosonological methods provide real-time determination of velocity, and spectral waveform of blood flow in basal intracranial arteries adds significant benefit to the care of the patients with neurovascular diseases. Several features, such as relative simplicity in terms of interpretation and performance, significantly low cost, totally non-invasiveness, portability, and excellent temporal resolution, make neurosonology increasingly popular tool for evaluation, planning, and monitoring of treatment, and for determining prognosis in various neurovascular diseases. Usefulness of transcranial Doppler in diagnosing/monitoring subarachnoid hemorrhage related vasospasm and sickle cell vasculopathy is already well known. Utility in diagnosis of intracranial arterial stenosis, acute occlusion and recanalization, intracranial hemodynamic effect of the cervical arterial pathologies, intracranial pressure increase, and cerebral circulatory arrest are also well established. Neurosonological determination of vasomotor reactivity, cerebral autoregulation, neurovascular coupling, and micro-embolic signals detection are useful in the assessment of stroke risk, diagnosis of right-to-left shunting, and monitoring during surgery and interventional procedures. Transcranial Doppler is also an evolving ultrasound method with a therapeutic potential such as augmentation of clot lysis and cerebral delivery of thrombolytic or neuroprotective agent loaded nanobubbles in neurovascular diseases. The aim of this study is to give an overview of current usage of the different ultrasound modalities in different neurovascular diseases., (© 2012 The Author Journal of Neurochemistry © International Society for Neurochemistry.)

The study included 148 patients with different combinations of multifocal atherosclerosis. The inclusion criteria were clinical manifestations of chronic cerebrovascular insufficiency concomitant with diseases of other arterial basins. The treatment strategies were chosen based on the results of examination by non-invasive methods for vascular visualization. Contrast agents were used only for curative purposes. The patients were divided into 2 groups depending on surgical strategy. Patients of group 1 underwent one-step reconstruction of several affected basins, those in group 2 step-by-step revascularization of different arterial basins with the use of X-ray endovascular interventions. The former approach was applied at the initial stage of the work. It creating a high risk of complications, the latter approach was preferred in the subsequent period. The incidence of complications in group 2 was 4.05% and the lethality rate 1.49%. These values were significantly higher in patients of group 1.

Purpose: Surgical outcome after microvascular decompression (MVD) for primary trigeminal neuralgia (TN) has been demonstrated as being related to the characteristics of the neurovascular compression (NVC), especially to the degree of compression exerted on the root. Therefore, preoperative determination of the NVC features could be of great value to the neurosurgeon, for evaluation of conflicting nature, exact localization, direction and degree of compression. This study deals with the predictive value of MRI in detecting and assessing features of vascular compression in 100 consecutive patients who underwent MVD for TN., Methods: The study included 100 consecutive patients with primary TN who were submitted to a preoperative 3D MRI 1.5 T with T2 high-resolution, TOF-MRA, and T1-Gadolinium. Image analysis was performed by an independent observer blinded to the operative findings and compared with surgical data., Findings: In 88 cases, image analysis showed NVC features that coincided with surgical findings. There were no false-positive results. Among 12 patients that did not show NVC at image analysis, nine did not have NVC at intraoperative observation, resulting in three false-negative cases. MRI sensitivity was 96.7% (88/91) and specificity 100% (9/9). Image analysis correctly identified compressible vessel in 80 of the 91 cases and degree of compression in 77 of the 91 cases. Kappa-coefficient predicting degree of root compression was 0.746, 0.767, and 0.86, respectively, for Grades I (simple contact), II (distortion), and III (marked indentation; p < 0.01)., Conclusion: 3D T2 high-resolution in combination with 3D TOF-MRA and 3D T1-Gadolinium proved to be reliable in detecting NVC and in predicting the degree of the root compression.

Background: Use of cadaveric cryopreserved saphenous vein grafts (CSVGs) has been described for peripheral vascular and coronary revascularization. The aim of this study is to recognize CSVGs as a potential alternative to autologous conduits for extracranial-intracranial (EC-IC) bypass in patients without available or suitable saphenous vein graft or radial artery. We report the short-term patency rate of CSVGs in EC-IC bypass., Methods: We present our preliminary experience in 10 patients using CSVG for cerebral revascularization. Data regarding operative indications, patient demographics, and bypass patency were collected., Results: The average age was 56 years old with equal sex distribution. The indications for the procedure were giant aneurysms in 7 patients, medically refractory vertebrobasilar ischemia in 2, and a skull base tumor in 1. ABO/Rh blood group compatible CSVG was used in each case. Postoperative angiography demonstrated patency in all cases. Quantitative magnetic resonance angiography was performed in 8 patients, demonstrating a mean bypass flow of 109 mL/min +/- 19 mL/min (mean +/- SE)., Conclusions: Use of CSVG for EC-IC bypass has not previously been reported. In our series, the short-term patency rate was 100%, better than that found in cardiac and peripheral vascular series, possibly because of the higher flow in EC-IC bypasses. Our preliminary experience suggests that CSVGs may be an option in patients without available autologous conduits, although longer follow-up is needed to assess long-term patency.

The p75 neurotrophin receptor (p75(NTR)) is involved in neuronal functions ranging from induction of apoptosis and growth inhibition to the promotion of survival. p75(NTR) expression is induced in the central nervous system (CNS) by a range of pathological conditions, where it seems to have a role in neuronal death and axonal growth inhibition. The cellular mechanisms driving p75(NTR) expression in cell lines and primary neurons is Sp1 dependent (Ramos et al. [2007] J. Neurosci. 27:1498). In this study, we analyzed the spatiotemporal profile of p75(NTR) expression after an ischemic lesion induced by cortical devascularization (CD). Our results show that p75(NTR) expression occurs in isolated neurons of the ischemic lesion site. The p75(NTR+) neurons presented morphological alterations and active caspase-3 staining. Some p75(NTR+) neurons were also positive for sortilin. The peak of p75(NTR) expression was localized 3 days postlesion (3DPL) in the penumbra. Sp1 transcription factor nuclear localization was observed in p75(NTR+) neurons. The overall level of Sp1 expression was increased until 14DPL on the ipsilateral hemisphere. With primary cortical neurons, we demonstrated that p75(NTR) expression is induced by excitotoxic stress and correlated with increased Sp1 abundance. We conclude that p75(NTR) expression is localized in selected neurons of the ischemic lesion and that these neurons are probably condemned to apoptotic cell death. In primary neuronal culture, it is clear that excitotoxicity and Sp1 are involved in induction of p75(NTR) expression, although, in vivo, some additional mechanisms are likely to be involved in the control of p75(NTR) expression in specific neurons in vivo., ((c) 2009 Wiley-Liss, Inc.)

Among the relatively few surgeons to be awarded the Nobel Prize was Alexis Carrel, a French surgeon and pioneer in revascularization surgery at the turn of the 20th century. The authors trace the humble beginnings of cerebral revascularization surgery through to the major developments that helped shape the modern practice of cerebral bypass surgery. They discuss the cornerstone studies in the development of this technique, including the Extracranial/Intracranial Bypass Study initiated in 1977. Recent innovations, including modern techniques to monitor cerebral blood flow, microanastomosis techniques, and ongoing trials that play an important role in the evolution of this field are also evaluated.

The surgical and endovascular treatment of cerebrovascular disorders (CVDs) in children, such as cerebral arteriovenous malformations, cavernous malformations, and moyamoya disease, have become commonplace and routine in many centers. As in the adult population, these procedures carry the risk of intraoperative cerebral ischemia. Therefore, similar strategies used to reduce the risk of cerebral ischemia in adults should be used in children. Unfortunately, there are no published studies on the intraoperative use of available techniques to identify, prevent, or potentially reverse cerebral ischemia. The goal of this article is to review the neurophysiologic techniques that may be useful and applicable in the surgical and endovascular treatment of pediatric CVDs, to describe the rationale and physiologic basis of their utility, to describe our experience in managing these cases, to present some of our results, and finally, to show the clinical utility of these techniques in the intraoperative management of CVDs.

Cerebral endovascular neurosurgery has evolved rapidly in the past decade through advances in tools and techniques and as a result of the thrust toward evidence-based medicine. More patients with diseases traditionally treated via microsurgical approaches can now be treated with techniques that focus on endoluminal reconstruction. With the introduction of intracranial clot retrievers and appropriately sized stents, stroke care is being slowly revolutionized for those patients with salvageable brain tissue at the time of admission to the hospital. In this article, the recent history, current state, and possible future of cerebral endovascular neurosurgery are reviewed for the following diseases: stroke, intracranial atherosclerotic disease, brachiocephalic occlusive disease, cerebral aneurysms, central nervous system vascular malformations, and brain tumors. New concepts and applications for endovascular treatment of epilepsy and multiple sclerosis are mentioned. The potential for nanotechnology in this field and the future endovascular suite are envisioned.

Object: The objective of this report is to describe a new approach to identify the optimal cortical target point for extracranial-intracranial (EC-IC) bypass surgery, to reliably find suitable recipient vessels for the anastomosis., Methods: Thirty consecutive patients (17 men and 13 women; mean age 54.6 +/- 11.79 years [+/- standard deviation]) with hemodynamic cerebrovascular insufficiency due to stenoocclusive arterial disease underwent EC-IC bypass surgery. The end of the Sylvian fissure was identified preoperatively using a specially designed template and external landmarks. At surgery, a 3-cm trephination was made, centered over the target point as determined by the template. The number, diameter, and length of the exposed cortical arteries were assessed using photographs and indocyanine green (ICG) angiograms., Results: At least 1 recipient artery appropriate for anastomosis (>or= 1 mm) was found in every craniectomy. The mean number of suitable recipient arteries per craniotomy was 2.09 +/- 0.87, the mean diameter was 1.28 +/- 0.24 mm, and the mean length 10.83 +/- 4.87 mm. Bypass patency was confirmed by intraoperative ICG angiography, postoperative computed tomography angiography, and digital subtraction angiography, and reached 100%., Conclusions: Performing a 3-cm craniectomy over the described target point, reliably allows access to suitable recipient arteries for EC-IC bypass surgery.

A 49-year-old man had left superior oblique myokymia for eight years. Magnetic resonance images with enhanced spoiled gradient recalled acquisition in the steady state (SPGR) and flow imaging using steady acquisition (FIESTA) disclosed a branch of the superior cerebellar artery lying on the root exit zone of the left trochlear nerve. Posterior fossa craniotomy confirmed the imaging findings. A Teflon pad was placed between the compressing artery and the trochlear nerve. The patient's superior oblique myokymia has completely resolved with a one-year follow-up. Only one such case has been previously reported. This is the first report to display the imaging findings.

Purpose of Review: This review summarizes recent advances in endovascular therapy for cerebrovascular disease., Recent Findings: For ruptured aneurysms, the only large, randomized, controlled trial comparing surgical and endovascular treatment (the International Subarachnoid Aneurysm Trial) resulted in a significant reduction in death or dependency at 1 year, compared with surgery, providing sound evidence that coiling should be the treatment of first choice. Data from the International Study of Unruptured Intracranial Aneurysms demonstrated that treatment of unruptured anterior circulation aneurysms of under 7 mm with no history of subarachnoid hemorrhage is not justified. Embolization of arteriovenous malformations, as sole therapy, is curative only in a small percentage of cases, but can be part of a multimodal approach for reducing arteriovenous malformation size prior to surgery or radiotherapy. Partial treatment of complex arteriovenous malformations may be more dangerous than no treatment. Protection devices can reduce complication rates in carotid artery stenting, but scientific evidence is still lacking. Until the results of comparative trials are available, carotid artery stenting is indicated only in selected patients. Angioplasty and stenting of intracranial arterosclerotic disease is feasible but remains a high-risk procedure, indicated only in highly selected patients. In acute stroke therapy, new thrombolytics and clot-retrieval devices may result in better recanalization rates., Summary: Advances in endovascular therapy have occurred in all areas of cerebrovascular disease. To obtain maximal patient benefit, endovascular treatment should be performed as an interdisciplinary approach in high-volume centers. Importantly, long-term follow-up review is necessary to clarify the overall role of endovascular treatment in the management of cerebrovascular disease.

The transcription factor NF-kappaB is a regulator of cell death or survival. To investigate the role of NF-kappaB in neuronal cell death, we studied its activation in a rodent model of stroke. In the ischemic hemisphere, NF-kappaB was activated, as determined by increased expression of an NF-kappaB-driven reporter transgene, nuclear translocation of NF-kappaB in neurons and enhanced DNA binding of NF-kappaB subunits RelA and p50. In p50 knockout mice, ischemic damage was significantly reduced. This indicates a cell death-promoting role of NF-kappaB in focal ischemia. NF-kappaB may provide a new pharmacological target in neurologic disease.

Purpose: The feasibility and safety of combining carotid surgery and thrombolysis for occlusions of the internal carotid artery (ICA) and the middle cerebral artery (MCA), either as a simultaneous or as a staged procedure in acute ischemic strokes, was studied., Methods: A nonrandomized clinical pilot study, which included patients who had severe hemispheric carotid-related ischemic strokes and acute occlusions of the MCA, was performed between January 1994 and January 1998. Exclusion criteria were cerebral coma and major infarction established by means of cerebral computed tomography scan. Clinical outcome was assessed with the modified Rankin scale., Results: Carotid reconstruction and thrombolysis was performed in 14 of 845 patients (1.7%). The ICA was occluded in 11 patients; occlusions of the MCA (mainstem/major branches/distal branch) or the anterior cerebral artery (ACA) were found in 14 patients. In three of the 14 patients, thrombolysis was performed first, followed by carotid enarterectomy (CEA) after clinical improvement (6 to 21 days). In 11 of 14 patients, 0.15 to 1 mIU urokinase was administered intraoperatively, ie, emergency CEA for acute ischemic stroke (n = 5) or surgical reexploration after elective CEA complicated by perioperative intracerebral embolism (n = 6). Thirteen of 14 intracranial embolic occlusions and 10 of 11 ICA occlusions were recanalized successfully (confirmed with angiography or transcranial Doppler studies). Four patients recovered completely (Rankin 0), six patients sustained a minor stroke (Rankin 2/3), two patients had a major stroke (Rankin 4/5), and two patients died. In one patient, hemorrhagic transformation of an ischemic infarction was detectable postoperatively., Conclusion: Combining carotid surgery with thrombolysis (simultaneous or staged procedure) offers a new therapeutic approach in the emergency management of an acute carotid-related stroke. Its efficacy should be evaluated in interdisciplinary studies.

Preliminary evaluation of the neuropsychological status of three Chinese-speaking patients receiving angioplasty and stenting of extracranial cerebral arteries showed no significant decline in their performance on cognitive tasks measuring (1) memory function, verbal and nonverbal memory, (2) attention, and (3) cognitive processing speed. Although angioplasty and stenting of extracranial cerebral arteries did not appear associated with detrimental changes in the cognitive status of the two patients completing all cognitive tasks, their relation must be confirmed as a neuropsychologically safe measure for reducing the risk of stroke in Chinese with significant extracranial cerebral artery stenosis by a randomized controlled study with a much larger sample.

Surgical presence in the treatment of acute stroke patients is becoming increasingly aggressive. This article presents the current standards for stroke surgery in the acute setting, and defines those patient groups that represent appropriate candidates for such intervention.

Acute ischemia in the complete territory of the carotid artery may lead to massive cerebral edema with raised intracranial pressure and progression to coma and death due to uncal, cingulate, or tonsillar herniation. Although clinical data suggest that patients benefit from undergoing decompressive surgery for acute ischemia, little data about the effect of this procedure on experimental ischemia are available. In this article the authors present results of an experimental study on the effects of decompressive craniectomy performed at various time points after endovascular middle cerebral artery (MCA) occlusion in rats. Focal cerebral ischemia was induced in 68 rats using an endovascular occlusion technique focused on the MCA. Decompressive craniectomy was performed in 48 animals (in groups of 12 rats each) 4, 12, 24, or 36 hours after vessel occlusion. Twenty animals (control group) were not treated by decompressive craniectomy. The authors used the infarct volume and neurological performance at Day 7 as study endpoints. Although the mortality rate in the untreated group was 35%, none of the animals treated by decompressive craniectomy died (mortality 0%). Neurological behavior was significantly better in all animals treated by decompressive craniectomy, regardless of whether they were treated early or late. Neurological behavior and infarction size were significantly better in animals treated very early by decompressive craniectomy (4 hours) after endovascular MCA occlusion (p < 0.01); surgery performed at later time points did not significantly reduce infarction size. The results suggest that use of decompressive craniectomy in treating cerebral ischemia reduces mortality and significantly improves outcome. If performed early after vessel occlusion, it also significantly reduces infarction size. By performing decompressive craniectomy neurosurgeons will play a major role in the management of stroke patients.

We managed ten cases of EC-IC bypass using a vein graft; six cases with multiple cerebral arterial occlusion and four cases with aneurysm necessitating therapeutic occlusion of the parent artery (Table). Patency of the graft was confirmed in seven cases on long-term follow-up ranging from 7 months to 5 years. Of the ten cases, two died within 7 days after surgery from causes unrelated to the bypass and one was lost in follow-up surgery. Hemorrhagic infarction was observed in two cases, one of which underwent removal of the hematoma. In five cases with cerebral occlusive disease, there were no additional ischemic events and two cases with giant aneurysms showed improvement of visual acuity and extraocular movement. We improved on several surgical techniques for vein graft. We used small hemoclips to occlude branches of the saphenous vein instead of ligating them, which shortens the harvesting time of the saphenous vein. Vessel cannula with a small-sized elegant tip and one-directional valve (DLP, INC., USA) was also used to inflate or deflate vein grafts with saline. It was easily attached to the graft and minimized air entrapment in the lumen. Small clips for microvascular anastomosis (Mizuho INC., Japan) were used to temporarily occlude branches or perforators from the recipient artery. One of the branches of the graft was dissected long enough, through which intraluminal air or thrombus was washed out at the final stage of the surgery. These procedures are useful for shortening occlusion time of the recipient artery and decreasing the risk of embolism.

The effect of superficial temporal artery-middle cerebral artery anastomosis on regional cerebral blood flow (rCBF) was measured on 31 patients with ischemic cerebrovascular diseases. rCBF was measured on the precentral and superior temporal gyri during surgery using the thermal diffusion technique. The mean rCBF was significantly lower than controls before anastomosis, but increased significantly after. Severer clinical symptoms were associated with lower rCBF. The rCBF increased significantly in patients with transient ischemic attack, reversible ischemic neurological deficit, and minor and major completed stroke. All 31 patients demonstrated dysautoregulation, both before and after anastomosis. However, the rCBF had increased above the ischemic threshold during hypotension, achieving a reserve capacity to prevent hemodynamic stroke.

We evaluated the effects of the STA-MCA anastomosis on local cerebral blood flow (LCBF) and CO2 cerebrovascular reactivity (CVR) in ischemic cerebrovascular diseases (CVD). [Patients and Methods] We examined the LCBF and CVR of 21 patients with ischemic CVD subjected standard STA-MCA anastomosis. During surgery, LCBF was continuously measured using the thermal diffusion method sometimes in a state of decreased PaCO2 (median: 7.2mmHg) before and after bypass. CVR was represented as % delta LCBF/delta CO2. [Results] 1) In the control group (with non-ruptured aneurysm, n = 7), LCBF was 58.6 +/- 14.1 ml/100g/min and % delta LCBF/delta CO2 was 4.68 +/- 1.68%/mmHg. 2) Before bypass, LCBF was 46.7 +/- 10.3ml/100g/min. It was significantly (p < 0.05) lower than control level. After bypass, LCBF increased significantly (p < 0.05) to 62.0 +/- 14.3 ml/100g/min. 3) Before bypass, % delta LCBF/delta CO2 was -1.36 +/- 4.34%/mmHg. In the 14 cases (66.7%), % delta LCBF/delta CO2 was below the 0%/mmHg (inverse steal effect). 4) After bypass, it increased to 0.08 +/- 2.73%/mmHg. 11 cases (52.4%) showed % delta LCBF/delta CO2 was above the 0%/mmHg. 5) In the group with a preoperative % delta LCBF/delta CO2 of less than 0%/mmHg, preoperative LCBF was 43.6 +/- 9.3 ml/100g/min, which was significantly low (p < 0.01) compared to that in the group with higher % delta LCBF/delta CO2. After bypass, LCBF and % delta LCBF/delta CO2 remarkably increased in the group with % delta LCBF/delta CO2 below 0%/mmHg. [Conclusion] Before bypass, LCBF was low and CVR was severely disturbed. In the 14 cases % delta LCBF/delta CO2 was below 0%/mmHg.(ABSTRACT TRUNCATED AT 250 WORDS)

Sixteen patients with minor completed stroke in the chronic stage underwent superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis. The acetazolamide-activated regional cerebral blood flow (rCBF) was measured 20 minutes after the injection using inhalation of stable xenon and computed tomographic scanning (Xes CT-CBF study) pre- and postoperatively. Eleven patients (Group 1) showed immediate improvement in neurological state within a few days of the operation, while five (Group 2) showed no improvements. Preoperative rCBF in the ischemic areas without infarction was 30.8 +/- 3.0 ml/100 gm/min in Group 1 and 53.0 +/- 5.2 ml/100 gm/min in Group 2. Preoperative vasodilatory capacity with acetazolamide in Group 1 was 5.7 +/- 8.6 and significantly increased to 19.8 +/- 4.9 after surgery. In Group 2, pre- and postoperative vasodilatory capacity was 12.7 +/- 3.1 and 14.9 +/- 2.9, respectively, and there was no significant change. These results suggested that minor stroke patients with moderate decrease of affected side rCBF (less than 40 ml/100 gm/min) and with hemodynamic impairment may have the surgical indication for STA-MCA anastomosis.

We created a highly reproducible stroke model in dogs by the selective occlusion of middle and anterior cerebral artery branches that penetrate the anterior perforated substance and supply much of the basal forebrain. We also analyzed the anatomic organization of the arterial supply to this region in this animal. Perforators came from anterior communicating artery branches similar to the recurrent artery of Heubner in humans and from the middle cerebral artery at several sites distal to the bifurcation of the internal carotid artery. Although some animals had a single source of the perforating arteries, most had two or more. In 50% of our specimens, the anterior communicating artery was the dominant source of arterial supply, in 21% the middle cerebral artery was dominant, and in 24% neither source dominated. Occlusion of all microscopically visible perforators to the anterior perforated substance reliably resulted in infarction of the internal capsule (100%), caudate nucleus (91%-100%), putamen or globus pallidus (82%-91%), and anterior commissure (73%). Structures involved less frequently in infarctions include the external capsule, claustrum, anterior commissure, and septal nuclei. We believe this anatomic information is useful for understanding why previous focal ischemia lesions in the distribution of the middle cerebral artery in the dog have been highly variable as well as for planning and interpreting future studies in this species. The proposed model of focal ischemia may be of use for the study of stroke.

The authors present a review of published experience with intracranial-extracranial arterial bypass grafting. The procedure is technically feasible and has a relatively low morbidity and mortality when performed by experienced microvascular surgeons. However, its therapeutic value is still unproven.

Case 1. A 65 year old male had left hemiparesis with sudden onset since 8 years ago, which gradually aggravated for these 2 years. On Sept. 27, 1973, he was admitted to the Department of Neurosurgery, Kitano Hospital. There was left spastic hemiparesis with hemisensory disturbance and he could not walk without help for the maked spasticity. Left carotid angiogram revealed the complete occlusion of the internal carotid artery and marked stenosis of the external carotid artery at the common carotid bifurcation. External carotid endarterectomy was performed on Nov. 19, 1973, which was followed by STA-MCA anastomosis 2 months later. The spasticity of extremities and left hemisparesis were gradually improved and he was able to walk without help. Case 2. On Apr. 14, 1974, a 63 year old female developed complete stroke with right hemiparesis and speech disturbance after transient ischemic attacks of 5 days duration. On Aug. 9, he was admitted and had emotional incontinence, right hemiparesis, Gerstmann's syndrome and motor aphasia. Left carotid angiogram revealed a saccular aneurysm of the middle cerebral artery and the occlusion of the distal middle cerebral arterys. These findings suggested that the occlusion was caused by embolus from the middle cerebral aneurysm, and the combined surgery with STA-MCA anastomosis and operation for the aneurysm was planned. On Aug. 30, 1974, under left frontotemporal craniotomy, aneurysmal neck clipping and aneurysmectomy were performed and thereafter, STA-MCA double anastomosis was done. One week after operation, the gradual improvement of pre-operative symptomes was noted. Recently, STA-MCA anatomosis is well known to be one of the effective operative methods for the occlusive methods for the occlusive cerebrovascular diseases and in addition, we found that the combination of STA-MCA anastomosis with other operations was effective for unusual cases presenting in this report. Furthermore, except for the occlusive cerebrovascular diseases, we usually plan STA-MCA anastomosis for the cases of 1) carotid ligation or trapping for carotid-cavernous sinus fistula and some internal carotid aneurysms, 2) some intracranial tumors with the danger involving the main cerebral arteries by operation to protect the cerebrovascular insufficiency.

A review of the present status of neurosurgical vascular bypass for problems of cerebrovascular occlusive disease is presented. In 70 patients who have undergone operations by one surgical team, the results are most encouraging in cases of transient ischemic attacks with hemodynamic lesions previously considered inoperable or inaccessible in the cerebral vasculature. The morbidity rate is acceptable and the present operative mortality rate is 1.4 percent.

Forty-one intraoperative angiograms were performed on 39 patients undergoing surgical therapy for aneurysms or excision of deep arteriovenous malformations. Good quality radiographs were produced in each case using commonly available equipment. One nonfatal stroke syndrome was the only serious complication possibly attributable to these angiograms. The techniques of opacifying the anterior and posterior intracranial circulations are described and the value of angiography in the intraoperative situation is discussed.

This is a report on a series of 100 consecutive patients who had undergone microvascular arterial bypass surgery as an aid in the treatment of occlusive ischemic cerebrovascular disease. The results to date are encouraging in cases of transient ischemic attacks (TIA) with significant hemodynamic vascular lesions previously considered inaccessible or inoperable by conventional vascular surgical techniques. The permanent morbidity rate is low. The operative mortality rate is acceptable. Postoperative patency rates of the surgical bypass remain high. In analyzing the cases presenting with TIA, the total incidence postoperatively to stroke is 6% in the series to date. The average postoperative follow-up is 20 months.