Kazumi Ogane

Dissecting Aneurysms of Intracranial Carotid Circulation

Background and Purpose— Clinical features of nontraumatic dissecting aneurysms of intracranial carotid circulation remain unclear because investigation of this disease has been limited to case reports. The aim of this study was to investigate the clinical features of this disease through the use of cooperatively collected cases. Methods— The cases diagnosed as dissecting aneurysms of intracranial carotid circulation on the basis of clinical signs and neuroradiological findings in 46 stroke centers from 1995 through 1999 were collected, and their clinical features were analyzed. Results— Forty-nine cases of dissecting aneurysms of intracranial carotid circulation were collected. Thirty-two patients presented with subarachnoid hemorrhage (SAH), and 17 presented with cerebral ischemia. The ratio of this disease to all intracranial dissecting aneurysms treated in the same institutes for the same period was 19.1%, and the ratio of SAH resulting from this disease to SAH of unverified origin treated in the same institutes for the same period was 6.2%. The predominant site of lesion was the internal carotid artery in 18 of 32 patients (56%) with SAH and the anterior cerebral artery in 13 of 17 patients (76%) with cerebral ischemia. The predominant angiographic findings were that stenosis with dilatation occurred in 20 of 32 patients (63%) with SAH and stenosis without dilatation was seen in 11 of 17 patients (65%) with cerebral ischemia. Poor prognosis was seen in 21 of 32 patients (66%) with SAH, which was due largely to rebleeding seen preoperatively, during operation, and even postoperatively when clipping or wrapping of the aneurysmal bulge was performed. Conclusions— Nontraumatic dissecting aneurysm of intracranial carotid circulation is not as rare as expected. It seems to be one of the important causes of SAH of unverified origin.

Impairment of anti-platelet-aggregating activity of endothelial cells after experimental subarachnoid hemorrhage.

Background and Purpose Serial changes of anti-platelet-aggregating activity in the endothelial cells after experimental subarachnoid hemorrhage were studied in 30 feline two-hemorrhage models. Methods One hour or 2, 4, 7, or 14 days after mimic subarachnoid hemorrhage, ADP (40 mg/kg) was infused into the basilar artery via the right vertebral artery to activate circulating platelets. Immediately after ADP infusion, the basilar artery was fixed by intra-arterial perfusion with 1.5% glutaraldehyde in 0.1 mol/L phosphate buffer and was removed. The luminal surface was examined under a scanning electron microscope. Results One hour after subarachnoid hemorrhage, no platelets adhered or aggregated on the luminal surface. However, 4 to 7 days after subarachnoid hemorrhage, many platelets were observed adhering or aggregating on the luminal surface. Conclusions These findings suggest the impairment of anti-platelet-aggregating activity of endothelial cells after subarachnoid hemorrhage. This impairment may be involved in inducing cerebral ischemia during cerebral vasospasm by causing platelet adhesion and aggregation.

Usefulness of acellular dermal graft as a dural substitute in experimental model

BACKGROUND Friction injury of cortical surface or cerebrospinal fluid leakage are the major complications of polytetrafluoroethylene (ePTFE) duraplasty because of their strong surface tension and lesser adaptability. Autologous duraplasties are also accompanied by potential donor-site complications and are inappropriate for large defects. Acellular Dermal Graft (ADG), prepared from cadaver human skin, does not have the above-mentioned drawbacks because of its human nature. Moreover, the dermal basement membrane and supporting tissues remain intact, so the rate of cellular migration and transformation to the surrounding host tissue is supposed to be excellent. We studied ADG in canine model to observe the rate of transformation into the surrounding dura mater via collagen synthesis from the invaded fibroblasts to evaluate its usefulness as a duraplasty. METHODS Dural grafting surgery was performed on 6 adult mongrel dogs weighing from 8 to 12 kgs under general anesthesia. Three dogs were sacrificed after 1 month (acute) of surgery and the other three (chronic) were sacrificed after 3 months with overdose of pentobarbital sodium. Transcardiac perfusion-fixation with 4% paraformaldehyde was done. Hematoxylin-eosin and trichrome masson stains were performed to see the graft cellularity. Thickness of grafts was also assessed along the length of the histologic sections. RESULTS Duralization, which was microscopically characterized by infiltration with regular array of collagen fibers, was observed at a few places in every high-power field in acute group. But in chronic animals, where dermal side of ADG was facing towards cranium, duralization was excellent. CONCLUSIONS Our result suggests that ADG can be considered as a useful dural substitute.

Assessment of Cerebral Microcirculatory Changes During Cerebral Vasospasm by Analyzing Cerebral Circulation Time on DSA Images

Cerebral microcirculation is disturbed during cerebral vasospasm, however, its influence on cerebral blood flow (CBF) and delayed ischemic neurological deficits (DIND) has not been determined, since there has been no easy method to evaluate microcirculatory changes. Cerebral microcirculation is regulated by regional cerebral blood flow (rCBF), cerebral circulation time (CCT), and regional cerebral blood volume (rCBV). In order to evaluate microcirculatory changes, CCT was measured on digital subtraction angiography (DSA).

Efficacy of steroid hormone in solution for intracranial irrigation during aneurysmal surgery for prevention of the vasospasm syndrome

SummaryA series of 55 patients with ruptured cerebral aneurysms were treated with moderate removal of subarachnoid clot followed by intracranial irrigation with pH 8.0 Hartmann solution containing 1 mg/ml of methylpredonizolone sodium succinate after the aneurysmal clipping during early (before day 3) operation. Six (11%) of the 55 patients suffered vasospasm syndrome postoperatively. The clinical results are significantly better than a series of 68 patients operated on and treated before day 3 by intracranial irrigation with Hartmann solution (pH 8.0) only. The possible preventive effect of direct intracranial administration of steroid hormone is discussed.

Displacement of central sulcus in cerebral arteriovenous malformation situated in the peri-motor cortex as assessed by magnetoencephalographic study

SummaryBackground. Intra-operative monitoring of the position of the central sulcus (CS) is indispensable to properly treat a peri-motor cortex lesion. Noninvasive preoperative studies for identification of CS are also needed for choosing the optimal operative procedure. Magneto-encephalography (MEG) has recently been introduced for non-invasive preoperative investigation and cortical functional mapping. Methods. Stereotactic mapping of functional CS anatomy was performed preoperatively on 13 subjects using somatosensory evoked fields with MRI-linked whole head MEG system. All subjects had a left sided peri-motor cortex lesion with diagnoses including the following conditions: three arteriovenous malformations (AVM), seven gliomas, three meningiomas. Findings. Functional CS in supratentorial brain tumor and parietal AVM cases corresponded with anatomical CS identified by MRI. But the AVM cases in whom the nidus was situated within the peri-motor cortex showed discrepancies between anatomical CS and functional CS. Interpretation. Careful consideration of the operative procedure combined with non-invasive cortical functional mapping is needed to optimally treat AVM and congenital brain lesions situated in the anatomical peri-motor cortex.

A simple self-retaining cerebral retractor. Technical note.

SummaryA flexible copper spatula, usually used by us as retractor in brain surgery, was easily converted to be come self-retaining without any other apparatus, by a simple minor modification.

Progressive edematous lesions in subacute phase after neuroendovascular therapy

Background: The appearance of edematous lesions in the subacute phase is a rare complication following neuroendovascular therapy. Effective management of these lesions remains unclear. In this report, a case with progressive edematous lesions in the subacute phase after neuroendovascular therapy was described, and the clinical features and therapeutic strategies were discussed. Case Description: A 54-year-old female with a large, right cavernous internal carotid artery aneurysm was treated with a flow diverter. Left hemiparesis developed 15 days after the procedure, and multiple edematous lesions in areas of prior catheter procedures were revealed on radiological findings. Steroid pulse therapy was employed, and the lesions were gradually reduced without any additional neurological deficits. No recurrence was recognized in the follow-up study. Conclusion: In some reports, pathological findings indicate that these lesions result from the presence of foreign bodies, and emboli could be caused by cotton fibers or hydrophilic polymers used as surface coatings on endovascular catheters. In this case, the edematous lesions were most likely caused by hydrophilic polymer emboli. Steroid pulse therapy had a beneficial effect on the lesions. It is important to effectively manage prescribed periods after the procedure to avoid such a rare complication.

3D-FIESTA Magnetic Resonance Angiography Fusion Imaging of Distal Segment of Occluded Middle Cerebral Artery.

Middle cerebral artery (MCA) occlusion was examined with basi-parallel anatomical scanning (BPAS) using three-dimensional fast imaging employing steady-state acquisition (3D-FIESTA), and 3D-FIESTA and magnetic resonance angiography (MRA) fusion images were created. We expected that an incidence of hemorrhagic complications due to vessel perforations would be decreased by obtaining vascular information beyond the occlusion and thus acute endovascular revascularization could be performed using such techniques. We performed revascularization for acute MCA occlusion for five patients who were admitted in our hospital from October 2012 to October 2014. Patients consisted of 1 man and 4 women with a mean age of 76.2 years (range: 59–86 years). Fusion images were created from three-dimensional time of flight (3D-TOF) MRA and 3D-FIESTA with phase cycling (3D-FIESTA-C). Then thrombectomy was performed in all the 5 patients. Merci retriever to 1 patient, Penumbra system to 1, urokinase infusion to 2, and Solitaire to 1 using such techniques. In all cases, a 3D-FIESTA-MRA fusion imaging could depict approximately clear vascular information to at least the M3 segment beyond the occlusion. And each acute revascularization was able to perform smoothly using these imaging techniques. In all cases, there was no symptomatic hemorrhagic complication. It showed that 3D-FIESTA MRA fusion imaging technique could obtain vascular information beyond the MCA occlusion. In this study, no symptomatic hemorrhagic complications were detected. It could imply that such techniques were useful not only to improve treatment efficiency but also to reduce the risk of development of hemorrhagic complications caused by vessel perforations in acute revascularization.

Usefulness of acellular dermal graft as a dural substitute in experimental model: Commentary

BACKGROUND Friction injury of cortical surface or cerebrospinal fluid leakage are the major complications of polytetrafluoroethylene (ePTFE) duraplasty because of their strong surface tension and lesser adaptability. Autologous duraplasties are also accompanied by potential donor-site complications and are inappropriate for large defects. Acellular Dermal Graft (ADG), prepared from cadaver human skin, does not have the above-mentioned drawbacks because of its human nature. Moreover, the dermal basement membrane and supporting tissues remain intact, so the rate of cellular migration and transformation to the surrounding host tissue is supposed to be excellent. We studied ADG in canine model to observe the rate of transformation into the surrounding dura mater via collagen synthesis from the invaded fibroblasts to evaluate its usefulness as a duraplasty. METHODS Dural grafting surgery was performed on 6 adult mongrel dogs weighing from 8 to 12 kgs under general anesthesia. Three dogs were sacrificed after 1 month (acute) of surgery and the other three (chronic) were sacrificed after 3 months with overdose of pentobarbital sodium. Transcardiac perfusion-fixation with 4% paraformaldehyde was done. Hematoxylin-eosin and trichrome masson stains were performed to see the graft cellularity. Thickness of grafts was also assessed along the length of the histologic sections. RESULTS Duralization, which was microscopically characterized by infiltration with regular array of collagen fibers, was observed at a few places in every high-power field in acute group. But in chronic animals, where dermal side of ADG was facing towards cranium, duralization was excellent. CONCLUSIONS Our result suggests that ADG can be considered as a useful dural substitute.