I revisit items in an earlier paper of the same title, a review article that appeared in Nerv Syst Child (17: 219-229, 1992) with new conceptual understanding of the disease and its treatment. The items discussed are as follows. A. Is arachnoid incision needed in indirect anastomosis.? B. Does it take several months for an indirect anastomosis to have effects? C. Is surgery indicated for indirect anastomoses in the adult or the aged? D. Are indirect anastomoses less effective and trustworthy than direct operations? E. Does it matter little to discontinue the STA in the operation of moyamoya disease? F. Is surgery indicated for patients who just have occasional TIA attacks? G. Is surgery indicated for patients who just have headaches? H. Is surgery indicated for epileptic-type moyamoya patients? I. Is the operation not indicated for the seriously retarded? J. Are indirect anastomoses effective on the normal or infarcted brain? K. Under what circumstances is indirect anastomosis most effective? L. Should the operation be done bilaterally in one operation? M. Should an indirect operation be as extensive as possible? The answers are as follows. A. No arachnoid incision is needed in indirect anastomosis. B. It takes only weeks for an indirect anastomosis to have effects. C. Indirect anastomoses are indicated for the adult and the aged. D. It has never been proved scientifically that indirect anastomoses are less effective and trustworthy than direct operations. E. Discontinuance of the STA should be avoided if possible during the operation of moyamoya disease. F. Surgery is indicated even for patients who just have occasional TIA attacks. G. Surgery is also indicated for patients who just have headaches. H. Surgery also is indicated for epileptic-type moyamoya patients. I. Surgery is also indicated for the seriously retarded. J. Indirect anastomoses are less effective on the infarcted brain and much less so on the normal brain. K. Indirect anastomosis is most effective on live, misery perfused or hemodynamically-stressed brain. L. If the operation is to be done in two stages, the patient should be cautiously followed because the unoperated side deteriorates very rapidly in some cases. M. There should be an optimal extensiveness of an indirect operation in each case.
We assessed the posttreatment clinical course of 113 patients with moyamoya disease. All of them were treated with superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis with or without encephalo-myo-synangiosis. The mean follow-up duration was 14.4 years. Complete disappearance of the ischemic episodes was obtained in 110 patients (97.3%). Independent daily life activities were possible for 100 patients. Fifteen patients were incapable of social lives because of their mental retardation, although they can take care of themselves in their daily life. All of them suffered from preoperative completed stroke. Therepeutic time lag should be minimized to prevent these preoperative strokes.
Indirect revascularization for moyamoya disease can induce good neovascularization in most cases. However, its effect is not always reliable. In this study, we describe combined revascularization of direct bypass of the superficial temporal artery-middle cerebral artery anastomosis and indirect revascularization of encephalo-duro-arterio-myo-synangiosis (EDAMS) based on the preoperative radiological finding. The running course of the 3 donor arteries of the superficial temporal artery (STA), deep temporal artery (DTA) and middle meningeal artery (MMA) is superimposed on the lateral view of the patient's face using digital image technology. In surgery, using these digitally superimposed images, these 3 donor arteries were safely dissected without any injury and well vascularized soft tissue such as the galea aponeuritica, temporal muscle, and the dura mater were placed on the surface of the brain. There are many variations of techniques for the indirect revascularization for moyamoya disease. However, the well-vascularized tissues with preserved donor arteries are indispensable for the best indirect revascularization.
The branches of external carotid artery were separately used to revascularize all areas supplied by ACA, MCA and PCA. The parietal branch of STA was usually used for an end to side anastomosis with a cortical branch of MCA. EDAS, using the proximal part of the frontal branch of STA, and EMS, using the inner layer of temporal muscle, were also performed in all pateints to stimulate spontaneous anastomosis. In addition, frontal burr holes were made to induce vascularization of the ACA areas from the distal part of frontal branch of ACA. If necessary, occipital burr holes in the area supplied by occipital artery was also added for the PCA territories. The first operation was performed on the dominant side, then a similar procedure was performed on the opposite side after an interval of at least 3 months. Postoperative clinical symptoms improved in most of the cases. The findings from MRI, MRA, angiography, and SPECT demonstrated an improvement of cerebral circulation through operative sites with disappearance of abnormal vessels. Rapid normalization of the EEG occurred within a year in more than half of the pateints. These results suggest that the placement of frontal and occipital burr holes, in addition to STA-MCA anastomosis, EDAS, and EMS, is effective in vascularizing the ischemic areas in patients with moyamoya disease.
The area of revascularization using the temporal muscle and/or the superficial temporal artery is restricted to the lateral aspect of the cerebral hemisphere because these donor tissues distribute inferior to the superior temporal line. To improve the surgical result, the residual ischemic area in the superior aspect of the hemisphere should be revascularised. Dural arteries are appropriate donors for this purpose. At surgery, the dura near the middle meningeal artery was split into outer and inner layers, and the split surfaces of the outer layers were attached to the cortex. This procedure, combined with encephalo-duro-arterio synangiosis, was applied to 25 hemispheres in 18 patients with pediatric moyamoya disease (mean age, 6 years). Postoperative selective angiograms of the middle meningeal artery demonstrated effective cortical revascularization covering the superior aspect of the hemisphere. All the patients were symptom free by 1.5 years after surgery. Revascularization of the superior aspect of hemisphere is an important consideration for the improvement of surgical results.
We present the results of percutaneous transluminal angioplasty (PTA) with/without stenting for cervical internal carotid artery (ICA) stenosis. A total of 36 high-grade stenoses (> 70%) in 31 patients were treated, in which 25 lesions in 20 patients were treated with PTA and 11 lesions in 11 patients were treated with stenting. All patients were successfully treated and no adverse events occurred during procedures. Postprocedural angiography showed that significantly larger diameters were obtained in stenting group than in PTA group. Dissection occurred in 6 (24%) patients in the PTA group, whom 1 patient was subsequently treated with carotid endarterectomy and 2 with stenting. In contrast, no dissection was observed in the stenting group. Restenosis occurred in 4 (16%) in the PTA group, but not in the stenting group. As postoperative complications, ischemic neurological deterioration was observed in 1 patient in the PTA group, and 1 ipsilateral subcortical hemorrhage and 1 myocardial infarction were observed in the stenting group. No stent deformation was observed during follow-up period. These results suggest that stenting provides a lower rate of dissection and restenosis than conventional PTA as a treatment for cervical ICA stenosis. Stenting may be a promising method to treat these lesions. Appropriate stents for carotid stenosis and brain protection system should be developed.
We retrospectively analyzed 73 patients of vertebro-basilar artery aneurysms experienced over the last six years to demonstrate the selection of the treatment modality and its efficacy in our department. Forty-eight cases presented subarachnoid hemorrhage (SAH), and half of them were in grade IV and V at admission. The locations of the aneurysm were 24 basilar tip, 15 basilar-superior cerebellar (BA-SCA), 4 basilar trunk, 2 vertebral union, 13 vertebro-posterior inferior cerebellar and 15 vertebral dissecting aneurysms. Surgical obliteration or endovascular embolization with GDC were determined considering patient condition, age, angio-architecture and shape of the aneurysm. Direct neck clipping was performed 73% of SAH and 63% of non-ruptured cases. Coil embolization was more frequently selected than for supratentorial aneurysms. Favorable outcomes were obtained 49% of SAH and 90% of non-ruptured patients. Microsurgical clipping is superior to coil embolization in mainly the following aspects: confirmed permanent obliteration, reduced intracranial pressure, controllable intraoperative bleeding and clean-up of SAH for preventing vasospasm. Endovascular treatment can be the treatment of choice in cases when patients are aged or in poor condition, having superiorly or posteriorly protruding BA-tip aneurysms. Recently developed skullbase surgical technique and intraoperative collaboration with endovascular technique can minimize the draw-back of open surgical treatment such as excess brain retraction and perforator occlusion.
An aneurysm arising from the posterior communicating artery itself is named true posterior communicating artery aneurysm (true PcomA), of which the incidence is less than 5% of aneurysms arising around the origin of the posterior communicating artery (Pcom). We successfully operated on a case with true PcomA with removal of the anterior clinoid process. The patient is a 66-year-old male who suddenly developed consciousness disturbance. Emergency head CT showed subarachnoid hemorrhage, and he was referred to our center for surgical treatment. His consciousness became clear after admission. Cerebral angiography revealed left true PcomA projecting inferomedially. He had undergone by-pass surgery for aortitis syndrome with artificial vessels 33 years earlier. The bilateral subclavian arteries were occluded, and bilateral vertebral arteries were not seen on aortography. The vertebrobasiler system was filled from the anterior circulation via the Pcoms. We took a left pterional approach, removed the anterior clinoid process and incised the dural ring to provide wide working space, because the aneurysm was below the internal carotid artery and the optic nerve, the dome of which adhered to the base of the middle cranial fossa. After we dissected the adhesion between the aneurysm and the Pcom, the proximal neck was found to be located 3-4 mm from the origin of the Pcom. The aneurysm was clipped with Yasargil's titanium clip. The postoperative course was uneventful, and the patient was discharged with no neurological deficit. We consider that hemodynamic stree may play an important role in the development of true PcomA associated with occlusion of major vessels.
We report excellent results for 20 patients who underwent multiple burr-hole operations for moyamoya disease. Beginning at a year postsurgery, angiograms disclosed rich neovascularization at 86 of 95 burr-holes, first from the middle meningeal artery, then from the superficial temporal artery. Neovascularization did not occur at 9 burr holes at which there were subdural effusion, local cerebral atrophy, and rich collaterals. Transient ischemic attacks disappeared in 8 patients and remarkably decreased in 1 patient. Preoperative symptoms improved in 5 of the patients who presented with cerebral infarction, in 3 patients with intracerebral hemorrhage, and in 3 patients with intraventricular hemorrhage. In 4 of 9 patients in whom moyamoya disease progressed angiographically, the symptom recurred but finally improved after addition of the burr-holes. Another 5 patients presented no new symptoms. In a patient with intracerebral hemorrhage, a small rebleeding occurred with no symptom. A high rate (10%) of chronic subdural hematoma occurred postoperatively. We strongly recommend the multiple burr-hole operation as the surgical treatment of choice for moyamoya disease because of its safety and effectiveness.
To evaluate the efficacy of Ribbon encephalo-duro-arterio-myo-synangiosis (EDAMS) for patients with childhood moyamoya disease, we analyzed pre- and postoperative cerebral hemodynamics at resting and at acetazolamide-challenging in the areas of the anterior cerebral arteries (ACAs) and the middle cerebral arteries (MCAs). We reviewed 10 children with moyamoya disease treated with Ribbon EDAMS. The value of cerebral perfusion (CP) was obtained by dividing the radioisotope uptake in each ROI by the mean uptake in the cerebellum measured using 99mTc-hexamethyl-propyleneamine oxime single-photon emission CT. The value of vasodilatory capacity (VDC) was defined as the change in CP of each ROI after acetazolamide-challenging. Pre-existing clinical symptoms disappeared after Ribbon EDAMS in 8 patients. The other 2 patients needed another supplementary reconstructive surgery to resolve the neurological problems. CP at resting in the areas of the MCAs (n=38) changed significantly from 0.98±0.18 to 1.04±0.16 (P<0.05). VDC in the areas of MCAs (n=26) also improved from -15±21% to +6±19% (P<0.01). Although the changes of CP at resting in the areas of the ACAs (n=32, from 0.93±0.19 to 0.96±0.11) were not significant, VDC in the areas of the ACAs (n=20) improved from -22±29% to +5±19% (P<0.01). We conclude Ribbon EDAMS is effective to improve hemodynamic compromise in both areas of the ACAs and the MCAs in patients with childhood moyamoya disease.
We studied the angiographical effect of the encephalo-galeo-synangiosis (EGS) for moyamoya disease in each EGS of multiple EGSs method and selective EGS method, including combined methods such as the superficial temporal-middle cerebral artery anastomosis (STA-MCA) and encephalo-myo-synangiosis (EMS) with frontal (F-) and/or occipital (O-) EGS, EMS+EGS method and single F-EGS method. Furthermore, we compared postoperative filling area of the cerebral hemisphere via external carotid arteries after surgery between multiple EGSs method and selective EGS method except for single F-EGS method. Revascularization rate of each EGS-the percentage of EGS sites developed that collaterals-was 60% (46/77 sites) in multiple EGSs method and 71% (52/73 sites) in selective EGS method, including 70% (37/53 sites) in F-EGS and 75% (15/20 sites) in O-EGS. There was no definite difference of revascularization rate between patients 15 years old or younger (younger group) and patients 16 years old or older (older group) in both multiple EGSs and selective EGS methods. In multiple EGSs method, the filling area of the cerebral hemisphere was more than two-thirds of the hemisphere in 39% of 18 hemispheres operated, one-third to two-thirds in 22% and less than one-third in 39%. On the other hand, the filling area of the hemisphere after combined method and EMS+EGS method was more than two-thirds in 61% of 51 hemispheres, one-third to two-thirds in 35% and less than one-third in 4%. F- and O-EGS developed collaterals in the area of the anterior cerebral and posterior cerebral arteries, respectively. There was no difference of good filling rate of hemispheres between younger and older groups in both multiple EGSs and selective EGS methods. EGS can be done in any sites of the brain, and important factors to increase revascularization rate seem to be certain detection of areas with low cerebral blood flow without infarction, wider attachment of the galea to the brain, and preservation of the scalp and meningeal arteries that can be feeding arteries of EGS. Postoperative filling area of the cerebral hemisphere in the lateral view via external carotid arteries was wider in combined and EMS+EGS methods than in multiple EGSs method. The combined method including STA-MCA, EMS, F-EGS and/or 0-EGS seemed to be satisfactory to develop sufficient collateral formation of the cerebral hemisphere via the external carotid arteries without causing scalp complications.