Shinya Mandai

Surgical treatment of moyamoya disease: operative technique for encephalo-duro-arterio-myo-synangiosis, its follow-up, clinical results, and angiograms.

Moyamoya syndrome is defined as the development of collateral anastomosis pathways at the base of the brain, associated with chronic progressive stenosis of the carotid fork. Both reconstructive vascular surgery and conservative strategies are used to treat this syndrome, but the latter cannot prevent the disease from progressing. We describe the procedure of encephalo-duro-arterio-myo-synangiosis (EDAMS), and report the results in 17 patients (28 sides) who underwent EDAMS. The clinical symptoms of moyamoya disease include transient ischemic attacks, reversible ischemic neurological deficits, stroke, seizures, Gerstmanns syndrome, involuntary movements, or mental retardation resulting from the lack of cerebral blood flow. The clinical results of EDAMS were poor in one patient, fair in two, good in five, excellent in eight, and fair on one side and excellent on the other side in one patient. Postoperative angiograms showed widespread collateral circulation on the ischemic brain surface in patients undergoing EDAMS.

Surgical Treatment of Moyamoya Disease

Abstract Moyamoya syndrome is defined as the development of collateral anastomosis pathways at the base of the brain, associated with chronic progressive stenosis of the carotid fork. Both reconstructive vascular surgery and conservative strategies are used to treat this syndrome, but the latter cannot prevent the disease from progressing. We describe the procedure of encephalo-duro-arterio-myo-synangiosis (EDAMS), and report the results in 17 patients (28 sides) who underwent EDAMS. The clinical symptoms of moyamoya disease include transient ischemic attacks, reversible ischemic neurological deficits, stroke, seizures, Gerstmanns syndrome, involuntary movements, or mental retardation resulting from the lack of cerebral blood flow. The clinical results of EDAMS were poor in one patient, fair in two, good in five, excellent in eight, and fair on one side and excellent on the other side in one patient. Postoperative angiograms showed widespread collateral circulation on the ischemic brain surface in patients undergoing EDAMS.

CT angiography, MR angiography and rotational digital subtraction angiography for volumetric assessment of intracranial aneurysms. An experimental study

The purpose of our experimental study was to assess the accuracy and precision of CT angiography (CTA), MR angiography (MRA) and rotational digital subtraction angiography (DSA) for measuring the volume of an in vitro aneurysm model. A rigid model of the anterior cerebral circulation harbouring an anterior communicating aneurysm was connected to a pulsatile circuit. It was studied using unenhanced 3D time-of-flight MRA, contrast-enhanced CTA and rotational DSA angiography. The source images were then postprocessed on dedicated workstations to calculate the volume of the aneurysm. CTA was more accurate than MRA (P=0.0019). Rotational DSA was more accurate than CTA, although the difference did not reach statistical significance (P=0.1605), and significantly more accurate than MRA (P<0.00001). CTA was more precise than MRA (P=0.12), although this did not reach statistical significance. Rotational DSA can be part of the diagnosis, treatment planning and support endovascular treatment of intracranial aneurysms. The emerging endovascular treatment techniques which consist of using liquid polymers as implants to exclude aneurysms from arterial circulation would certainly benefit from this precise measurement of the volume of aneurysms.

Prophylactic Thrombosis to Prevent New Bleeding and to Delay Aneurysm Surgery

Six aneurysms in five patients with acute aneurysmal subarachnoid hemorrhages were treated with direct thrombosis using cellulose acetate polymer within 4 hours of rupture. The aneurysms involved the internal carotid and posterior communicating arteries (two patients), the anterior choroidal artery (one patient), the bifurcation of the basilar artery (one patient), and the middle cerebral artery (two patients). Four patients underwent aggressive volume expansion after direct thrombosis with cellulose acetate polymer. The aneurysms remained thrombosed until operations on the necks were performed 2 to 7 weeks after the subarachnoid hemorrhages. Three patients were given intrathecal tissue plasminogen activator. One patient, who remained at neurological Grade V, was not treated surgically and died from cardiac failure. Five aneurysms in the remaining four patients were successfully clipped. These preliminary data suggest that immediate aneurysmal thrombosis, then aggressive preoperative prophylactic volume expansion and/or administration of intrathecal tissue plasminogen activator, can help prevent new bleeding and reduce delayed cerebral ischemia in patients after aneurysmal subarachnoid hemorrhages.

Embolization of cerebral arteriovenous malformations with cellulose acetate polymer: a clinical, radiological, and histological study.

OBJECTIVE A cellulose acetate polymer (CAP) solution was hypothesized to be useful for the embolization of arteriovenous malformations (AVMs). To investigate this possibility, we analyzed the clinical, radiological, and histological results of patients with AVMs embolized by using a CAP solution. METHODS We reviewed the cases of 11 patients with AVMs treated by embolization before surgical resection. We used two types of CAP solutions, CAP-M and CAP-L, which are mixtures of 250 mg of solid CAP and 1800 or 2250 mg of bismuth trioxide dissolved in 5.5 or 7.0 ml of dimethyl sulfoxide, respectively. After the embolization procedure, percent reduction of the nidus volume was measured, and thereafter, the clinical course and computed tomographic scans and/or magnetic resonance imaging scans were evaluated. All patients underwent surgical resection 1 to 51 days after embolization. Resected specimens were stained for light microscopic examination. RESULTS Thirty-nine feeding vessels were embolized. The reduction rate of the nidus volume ranged from 20% to nearly 100%. Transient and persistent ischemic deficits occurred in three patients and one patient, respectively, and there were no hemorrhagic complications. All AVMs but one were completely resected by surgery. The embolized AVMs were soft enough to be easily cut and retracted. The histological examinations disclosed no or mild inflammatory reactions within 2 weeks after embolization. The internal elastic lamina was preserved in every case. Recanalization through the cast of the CAP mass was not observed until 51 days after embolization. CONCLUSION CAP solution is a safe and useful embolic agent for AVMs.

Direct Thrombosis of a Pseudoaneurysm after Obliteration of a Carotid-Cavernous Fistula with Cellulose Acetate Polymer

A 55-year-old man who suffered a head injury resulting in a left traumatic carotid-cavernous fistula was successfully treated with an intravascular detachable balloon. A pseudoaneurysm formed adjacent to the balloon. Seven months after the initial procedure, treatment with cellulose acetate polymer, a new liquid thrombotic material, occluded the pseudoaneurysm and preserved the internal carotid artery.

Curative treatment of cerebral arteriovenous malformations by embolisation using cellulose acetate polymer followed by surgical resection

AIM To investigate the usefulness of embolising cerebral arteriovenous malformations (AVMs) with a cellulose acetate polymer solution before surgical resection. METHODS The cases of 12 patients with AVMs treated by embolisation before surgical resection were renewed. Two types of cellulose acetate polymer solutions were used to occlude 40 feeding vessels. All patients underwent surgical resection 1-51 days after embolisation. RESULTS Reduction of the nidus volume after embolisation ranged from 20% to nearly 100%. Transient neurological deficits occurred in three patients, persistent deficits occurred in one and there were no haemorrhagic complications. All but one arteriovenous malformation were completely resected. Embolisation helped to identify feeding vessels and ease dissection. Histopathological examination of resected specimens disclosed mild inflammatory reactions in the acute stage and no unfavourable granulomatous changes in the chronic stage. CONCLUSION Embolisation with cellulose acetate polymer solutions followed by surgical resection is safe and efficacious for treating cerebral AVMs.

Partial thrombosis of canine carotid bifurcation aneurysms with cellulose acetate polymer.

OBJECTIVE To investigate the usefulness of a cellulose acetate polymer (CAP) solution for partial thrombosis of aneurysms. METHODS We created 14 canine cervical carotid bifurcation aneurysms, 11 of which were subsequently thrombosed partially with CAP solution. We then conducted angiographic and histological investigations. RESULTS Nine aneurysms were thrombosed 50 to 70% by volume, although a significant crescent crevice between the aneurysmal sac and the CAP mass was left in four of the aneurysms. In the remaining two aneurysms in which a crescent crevice had been seen in the initial stage of CAP injection, 80% and more than 95% thrombosis were needed to occlude the crevice, respectively. Follow-up angiograms of the seven aneurysms with no crescent crevice revealed no shifts of position of the CAP mass toward the bottom of the aneurysm sac, but slight ballooning of the remnants was observed in two of them. The angiograms of the other four aneurysms with significant crescent crevices demonstrated rupture with a massive hematoma in one and shifts of the CAP mass with marked enlargement of remnants in three. Histologically, the seven aneurysms with no enlarged remnants had newly developed membranes consisting of endothelium, infiltrated spindle-shaped cells, collagen, and elastic fibers. In contrast, in the three markedly enlarged aneurysms, there were only recent clots between the CAP mass and the aneurysm lumen and no development of endothelium. CONCLUSION Partial thrombosis with CAP solution is useful to keep aneurysms in a stable configuration, unless a crescent crevice has been left.

Progress in the management of patients with aneurysmal subarachnoid hemorrhage: A single hospital review for 20 years: Part I: Younger patients

BACKGROUND This study was carried out to clarify if there has been any improvement in the outcome of patients with aneurysmal subarachnoid hemorrhage during the past 20 years. Because elderly patients have apparently poorer prognoses than younger patients, patients older than 70 years were analyzed separately in the following article. METHODS Five hundred seventy-one patients with aneurysmal subarachnoid hemorrhage, under 70 years, who were consecutively admitted to Kagawa Prefectural Central Hospital from July 1972 to December 1992, were reviewed. These patients were divided into four groups according to the time of admission. The ultimate outcome was evaluated by means of Glasgow Outcome Scale 6 months after the ictus. RESULTS Changes in treatment protocol in this period included the induction of early surgery and the invention of a variety of modalities for the treatment of cerebral vasospasm. This resulted in a distinct increase in patients who actually underwent direct aneurysm clipping. Outcome has been significantly improved during this period, especially in patients with Hunt and Kosnik grade III (p<0.05, chi2). Patients in good clinical condition at follow-up (Glasgow Outcome Scale: good recovery) increased from 8.7% to 60.7%. Mortality decreased from 28.7% to 10.7%. CONCLUSIONS Current therapeutic modalities have significantly improved the outcome of patients with aneurysmal subarachnoid hemorrhage. Rebleeding before early surgery remains as a major cause of unfavorable outcome and further progress on this subject is mandatory.

Spiral versus J-shaped coils for neurovascular embolisation—an in-vitro study

Our purpose was to compare the characteristics of J-shaped detachable platinum coils with those of spiral coils in in-vitro vascular models. J-shaped coils consist of distal semicircular and proximal straight segments, the latter extending for most of the length of the coil. Spiral coils have a helical shape memory and are thus limited in expansion. In in-vitro silicone vascular models simulating intracranial aneurysms and dural arteriovenous fistulae, we compared J-shaped and spiral coils with regard to ease of delivery, anchoring and folding patterns, and stability in various types of vascular lumen. Delivery and retrieval were comparable. In large and irregular aneurysms and venous sinuses, J-shaped coils could form a more complex basket which conformed to the shape of the vascular cavity. The J-shaped coil was always in contact with the vessel wall. In wide-necked aneurysms, coil protrusion was more frequent with J-shaped coils, while spiral coils tended to stay compact and circular. Arteries were occluded in a shorter segment with spiral coils. J-shaped coils were safe and superior for large and irregular aneurysms or sinuses. Spiral coils were preferable for spherical aneurysms and segmental occlusion of arteries.