Bullet embolism of the median cerebral artery]

A shot injury to the middle cerebral artery caused occlusion to the vessel by thrombosis and emboly of the missile. The projectil had been removed, but a thrombus formed in the a. cerebri media as a postoperative complication or by progression of a thrombosis in the internal carotid artery and after 19 days the patient died. A focal emollition of the left cerebral hemisphere was found at autopsy.     

Spontaneous middle cerebral artery occlusion leading to moyamoya phenomenon and aneurysm formation on collateral arteries

BACKGROUND: Spontaneous middle cerebral artery occlusion associated with moyamoya phenomenon is distinct from moyamoya disease. The hemodynamic stress on the collateral channel occasionally leads to aneurysm formation, which may manifest as hemorrhage. The etiology of this disease has not been fully understood. CASE DESCRIPTION: A 63-year-old woman presented with left putaminal hemorrhage. The cerebral angiogram revealed a significant stenosis in the proximal segment of the left middle cerebral artery. Collateral arteries originating from the horizontal segment of the ipsilateral anterior cerebral artery and the ambient segment of the ipsilateral posterior cerebral artery supplied the middle cerebral artery distal to the stenosis. Both of the collateral channels had associated aneurysms that were surgically obliterated. The aneurysm on the collateral artery from the posterior cerebral artery was responsible for the putaminal hemorrhage. CONCLUSIONS: Spontaneous middle cerebral artery occlusion may lead to focal moyamoya phenomenon and aneurysmal intracerebral, intraventricular, or subarachnoid hemorrhage. The presence of a co-existing anomalous collateral artery in the present case suggests a congenital etiology of the focal middle cerebral artery occlusion.     

Spontaneous middle cerebral artery occlusion with moyamoya-like vessels associated with contralateral middle cerebral artery aneurysm; a case report]

A case of spontaneous middle cerebral artery occlusion with moyamoya-like vessels associated with contralateral middle cerebral artery aneurysm is reported. A 23-year-old male was admitted to our hospital with complaints of severe headache and vomiting. On admission CT scan demonstrated subarachnoid hemorrhage with high density in the left Sylvian fissure and suggested a ruptured left middle cerebral artery aneurysm. Carotid angiograms demonstrated a left middle cerebral artery aneurysm and an occlusion of the right middle cerebral artery at its origin with moyamoya-like vessels. There was no occlusion or stenosis in the bilateral intracranial internal carotid arteries. Furthermore, bilateral vertebral angiograms were also normal. The aneurysm was successfully clipped. The postoperative course was uneventful and the patient was discharged with no neurological deficit. So far as we could ascertain, there have been only 21 cases reported previously of spontaneous middle cerebral artery stenosis or occlusion with moyamoya-like vessels. According to angiographic studies and transcranial Doppler ultrasound findings, we are more inclined to believe that hemodynamic changes secondary to arterial occlusion lead to the formation and growth of aneurysms of the contralateral middle cerebral artery.     

成人出血型烟雾病54例DSA诊断与分析

目的分析成人出血型烟雾病的数字减影血管造影的影像学特点。方法 54例成人出血型烟雾病患者经股动脉穿刺插管行DSA血管造影。结果 54例患者中累及大脑前动脉31例,累及大脑中动脉19例,同时累及大脑前动脉、大脑中动脉18例,其中82.76%闭塞,7例累及大脑后动脉,6例出现基底动脉异常,7例合并动脉瘤。结论出血型烟雾病血管病变不仅累及大脑前、中动脉,大脑后动脉及基底动脉亦可累及,动脉闭塞多于狭窄,可出现于单侧型烟雾病,可合并动脉瘤,DSA检查是诊断烟雾病的最主要的手段。     

Comparative study of retrograde and selective cerebral perfusion with transcranial Doppler

BACKGROUND: Retrograde cerebral perfusion (RCP) is a simple technique and is expected to provide cerebral protection. However, its optimum management and limitations remain unclear. Transcranial Doppler has been used to monitor cerebral perfusion. Using this Doppler technique, we compared cerebral blood flow for RCP with that for selective cerebral perfusion. METHODS: Thirty-two consecutive patients underwent elective surgical repair of an aortic aneurysm involving the aortic arch at Kyushu University Hospital. Retrograde cerebral perfusion was used in 15 patients and selective cerebral perfusion, in 17 patients. Continuous measurement of middle cerebral artery blood flow velocities was performed by transcranial Doppler technique. RESULTS: Retrograde middle cerebral artery blood flow velocities during RCP could be measured in only 3 patients, whereas middle cerebral artery blood flow velocities during selective cerebral perfusion could be measured in all but 1 woman. The increase in middle cerebral artery blood flow velocities after RCP was significantly greater than that after selective cerebral perfusion. CONCLUSIONS: The measurement of middle cerebral artery blood flow velocities with transcranial Doppler technique is practicable during selective cerebral perfusion but difficult during RCP. The increase in middle cerebral artery blood flow velocities after RCP indicates reactive hyperemia and reflects the critical decrease in cerebral blood flow during this type of perfusion.     

Middle cerebral artery circulation during carotid surgery. A transcranial Doppler study

OBJECTIVE: Perioperative carotid cross-clamping might induce low stump pressures as well as hypoperfusion of the middle cerebral artery. In this study blood flow velocities in the middle cerebral artery were compared with intraoperative measurements of the poststenotic carotid blood pressure. DESIGN: Forty-one patients with internal carotid artery stenosis were operated on without shunting, under general anesthesia. Poststenotic carotid pressures and middle cerebral artery flow velocities were measured before and during cross-clamping. The hemodynamic responses to preoperative carotid compressions and intraoperative cross-clamping were evaluated. RESULTS: In seven patients the poststenotic carotid blood pressure decreased on clamping despite unchanged or even increased middle cerebral artery blood flow velocities. In all other patients, pressure changes were significantly correlated to the decrease in middle cerebral artery blood flow velocities. Autoregulatory blood flow velocity responses after preoperative common carotid artery compression were not reproducible by cross-clamping. CONCLUSIONS: Stump blood pressure measurements may not reflect middle cerebral artery perfusion in about 20% of thrombendarterectomies performed under general anesthesia. A possible explanation might be dimished cerebral autoregulation and changes in collateral flow distributions.     

Micro-anatomy of collateral perforating branches of the middle cerebral artery

The lenticulostriate arteries are the subject of a microanatomical study on 50 formalin fixed human brains. A single trunk arising from the middle cerebral artery is rarely found. In fact the branches are numerous and they are found to ramify before penetrating the anterior perforated substance. The length of the sphenoidal segment is variable and this aspect is discussed in the light of the literature data. The origin of the perforating branches is spread from the internal carotid artery to the bifurcation branches of the middle cerebral artery (M2 segment). On the other hand lenticulostriate arteries arising from the cortical branches of the middle cerebral artery are often found. These anatomical patterns are of essentially surgical interest. No branches must be damaged during the opening of the Sylvian fissure or during the dissection of an aneurysm in this region.     

Focal brain ischemia model in rats. An experimental study

Using 74 male rats, anatomical variations of branching of the proximal segment of the middle cerebral artery were studied. In 36 rats (28 Sprague-Dawley rats and eight spontaneously hypertensive rats), the middle cerebral artery and/or its branches were occluded at various sites. Occlusion of the middle cerebral artery at the lateral border of the olfactory tract with or without simultaneous ligation of the ipsilateral common carotid artery rarely caused cerebral infarction in Sprague-Dawley rats. Occlusion of the olfactory branch in addition to the trunk of the middle cerebral artery caused large infarction of the pallium in five of eight Sprague-Dawley rats. Occlusion of the middle cerebral artery at the medial border of the olfactory tract caused infarction in the pallium and/or basal ganglia in five of six rats, and neurologic deficits were severe and persistent. Occlusion of the middle cerebral artery at the lateral border of the olfactory tract in spontaneously hypertensive rats caused large infarction with severe neurologic deficits in all eight animals. Possible factors responsible for such diverse differences and the relative value of each group as an experimental model of focal cerebral ischemia in rats were discussed.     

Middle cerebral artery reconstruction

The authors have conducted an experimental study of the microanatomic features of the middle cerebral artery in unfixed human brains to assess the feasibility of reconstructive procedures within the Sylvian fissure. It was found that reconstructive procedures within the Sylvian fissure such as end-to-end, end-to-side, side-to-side, and grafting procedures were possible according to the anatomic data provided by our study. Possible surgical solutions to theoretical pathologic situations involving the middle cerebral artery vascular tree are highlighted and their feasibility is discussed.     

Anatomic pathways facilitating middle cerebral artery bypass

Occlusion of the middle cerebral artery by thrombi is a relatively common occurrence resulting in stroke. Prompt intervention by dissolution or bypassing the thrombi could reduce the severity of the effects. Here, the anatomic pathways facilitating a bypass are explored. Four possible arteries, the two superficial temporals, left and right, and two middle meningeals, left and right, are in positions adjacent to branches of the middle cerebral arteries, the trunks of which are located in the lateral fissures of the brain. The first possibility is anastomosing a branch of the superficial temporal artery with the middle cerebral artery segment in the lateral fissure where this segment is usually clear of thrombi. The second possibility is anastomosing a branch of the middle meningeal artery with the postthrombotic segment of the middle cerebral artery. These anastomoses are to be done with donor and recipient arteries of the same side. In the unlikely event that these two possibilities are lost, it is still possible to anastomose the affected middle cerebral artery with the superficial temporal or middle meningeal artery of the opposite side using several inches of saphenous vein.     

Ruptured aneurysm at a duplicated middle cerebral artery with accessory middle cerebral artery

Summary. Although many cerebral vascular anomalies are widely recognized, others are less well known or unclassified. Accessory middle cerebral artery (MCA) and duplicated MCA are among uncommon anomalies. We present a very rare case of subarachnoid haemorrhage due to rupture of a saccular aneurysm arising from a duplicated middle cerebral artery which was associated with an accessory middle cerebral artery.     

Middle Cerebral Artery Circulation During Carotid Surgery: A Transcranial Doppler Study

Objective - Perioperative carotid cross-clamping might induce low stump pressures as well as hypoperfusion of the middle cerebral artery. In this study blood flow velocities in the middle cerebral artery were compared with intraoperative measurements of the poststenotic carotid blood pressure. Design - Forty-one patients with internal carotid artery stenosis were operated on without shunting, under general anesthesia. Poststenotic carotid pressures and middle cerebral artery flow velocities were measured before and during cross-clamping. The hemodynamic responses to preoperative carotid compressions and intraoperative cross-clamping were evaluated. Results - In seven patients the poststenotic carotid blood pressure decreased on clamping despite unchanged or even increased middle cerebral artery blood flow velocities. In all other patients, pressure changes were significantly correlated to the decrease in middle cerebral artery blood flow velocities. Autoregulatory blood flow velocity responses after preoperative common carotid artery compression were not reproducible by cross-clamping. Conclusions - Stump blood pressure measurements may not reflect middle cerebral artery perfusion in about 20% of thrombendarterectomies performed under general anesthesia. A possible explanation might be dimished cerebral autoregulation and changes in collateral flow distributions.     

The accessory middle cerebral artery (author's transl)]

The accessory middle cerebral artery has rarely been documented. Four cases of the anomalous artery were found in 1240 carotid angiograms, the incidence being estimated to be 0.24 to 0.34%. Ages of the patients were 45, 52, 53, and 56. They were two males and two females. In two patients, the angiography was carried out because of positive neurological signs after head injury, and in the other two, because of cerebrovascular stroke. All the anomalous arteries were found as incidental findings. The angiography was carried out bilaterally in two patients and the anomalous arteries were found only on one side. They arose from the horizontal portion of the anterior cerebral artery and coursed laterally in paralled with the stem of the middle cerebral artery. Two of them gave rise to the perforating arteries into the brain which accompanied those from the middle cerebral artery. These atomalous arteries were identified very easily on an antero-posterior projection of the angiogram. In the most striking patient, the 52-year-old man, a selective angiography for the middle cerebral artery, which did not demonstrate the anterior cerebral artery and its branch, the accessory middle cerebral artery, was carried out and in the light of the findings, the accessory middle cerebral artery could be identified running in elliptic circle just above D1 on the lateral projection of the routine carotid angiogram. All the accessory middle cerebral arteries in our series were not associated with either intracranial aneurysm or anomalies such as agenesis of the corpus callosum and reduplication of the circle of Willis.     

Arachidonic acid metabolite production following focal cerebral ischemia: time course and effect of meclofenamate

Arachidonic acid metabolites have been implicated in the development of cerebral edema following ischemia. To define the time course of metabolite production, subtemporal craniectomies were performed on 60 male Sprague-Dawley rats (350-400 g). Thirty rats underwent middle cerebral artery occlusion while 30 rats underwent craniectomy alone. Five rats in each of two groups (middle cerebral artery occlusion and sham) were sacrificed at 15 minutes, 1 hour, 4 hours, 1 day, 3 days, and 6 days. The cerebral hemispheres were removed and divided in the midsagittal plane. Each hemisphere was immediately frozen in isopentane cooled in dry ice and stored at -70 degrees C. Tissue prostaglandins E2 and 6-keto F1 alpha, and leukotrienes (LT) B4 and C4 were measured by radioimmunoassay. Prostaglandin E2 and 6-keto prostaglandin F1 alpha were significantly elevated at 15 minutes in the middle cerebral artery occlusion hemispheres (p less than 0.05). Prostaglandins were not significantly elevated after 15 minutes. LT B4 and C4 were never significantly elevated. Meclofenamate, a nonsteroidal anti-inflammatory agent, was administered to 21 additional rats. Seven controls underwent middle cerebral artery occlusion alone, 7 were given intraperitoneal meclofenamate (20 mg/kg) 30 minutes prior to middle cerebral artery occlusion, and 7 underwent middle cerebral artery occlusion followed immediately by intraperitoneal meclofenamate (20 mg/kg). The animals were sacrificed at 15 minutes and similarly studied. There was a significant reduction of prostaglandin E2 and 6-keto prostaglandin F1 alpha following pretreatment with meclofenamate (p less than 0.01 and p less than 0.05). In pretreated rats, leukotrienes were not affected by meclofenamate. Similarly, prostaglandins and leukotrienes did not change when meclofenamate was administered after middle cerebral artery occlusion. We conclude that cyclo-oxygenase metabolite production begins within 15 minutes of middle cerebral artery occlusion. Treatment with meclofenamate prior to middle cerebral artery occlusion significantly reduced cyclooxygenase metabolite production, suggesting a protective effect of meclofenamate against ischemia-induced elevations of vasoactive prostaglandins implicated in the development of cerebral edema. Lipoxygenase metabolite production was not affected by middle cerebral artery occlusion or pharmacological intervention.     

Giant pediatric aneurysm treated with ligation of the middle cerebral artery with the Drake tourniquet and extracranial-intracranial bypass

Saccular intracranial aneurysms occur infrequently in children, and the incidence of pediatric giant aneurysms is statistically in the same proportion as in adults. The management of these giant aneurysms can be treacherous. This paper presents a case of a 9-year-old boy with a giant aneurysm of the right middle cerebral artery that was successfully managed by ligation of the middle cerebral artery using a Drake tourniquet with the patient awake and by augmentation of the middle cerebral artery circulation with superficial temporal artery-middle cerebral artery anastomosis without excision of the lesion.     

Surgical treatment and radiological consideration of supergiant cerebral aneurysms

We have collected four cases of supergiant cerebral aneurysm, each greater than 6.0 cm in diameter. Two of these cases were saccular aneurysms of the anterior communicating artery and middle cerebral artery, of which the necks were clipped with resection of the aneurysms. Another patient had a fusiform aneurysm of the middle cerebral artery, which was resected accompanied by a reconstructive procedure of cerebral blood flow. The last patient had a fusiform aneurysm of the internal carotid artery. Following internal carotid artery occlusion surgery with superficial temporal artery-middle cerebral artery anastomosis, the aneurysm completely disappeared radiologically within several months.     

Intracarotid Verapamil Decreases both Proximal and Distal Human Cerebrovascular Resistance

Background: The authors determined the segmental effects of intracarotid verapamil in human subjects by using a novel method of measuring proximal and distal cerebrovascular resistance. Their hypothesis was that intracarotid verapamil, a calcium channel-blocking drug that augments cerebral blood flow and reverses arterial spasm, would decrease both the proximal-conductance and the distal-arteriolar resistance.

Methods: Coaxial catheters were transfemorally floated into internal carotid and middle cerebral arteries during cerebral angiography. Pressures were recorded in the femoral, internal carotid, and middle cerebral arteries. Hemispheric cerebral blood flow was measured by the intracarotid 133Xe injection technique. Cerebrovascular resistance was measured for the proximal and distal arteries. Cerebral blood flow and hemodynamic data were recorded during intracarotid infusion of saline and verapamil (1 mg/min) for 5 min. Transcranial Doppler blood flow velocity in the middle cerebral artery was also recorded.

Results: Intracarotid verapamil increased in 133Xe cerebral blood flow from 43 +/- 11 to 59 +/- 11 ml [middle dot] 100 g-1 [middle dot] min-1 (P = 0.001; n = 9). The cerebrovascular resistance measured for the proximal and distal arteries decreased from 0.17 +/- 0.95 to 0.12 +/- 0.75 and from 1.63 +/- 0.78 to 1.03 +/- 0.33 mmHg [middle dot] ml-1 [middle dot] 100 g-1 [middle dot] min-1 (P < 0.01), respectively. The calculated proximal-conductive and distal-arteriolar (pial plus parenchymal) resistances showed a similar decrease. Transcranial Doppler measurements (n = 5) underestimated the effects of intracarotid verapamil that were consistent with an increase in middle cerebral artery diameter.     

Ruptured aneurysm at the origin of the accessory middle cerebral artery: case report

The accessory middle cerebral artery is a rare vascular anomaly of the brain. We describe a case of a ruptured aneurysm at the junction of the accessory middle cerebral artery and the horizontal portion of the anterior cerebral artery. The lesion was demonstrated by angiography and confirmed at surgery. No perforating arteries arising from this accessory artery were found. There have been only four previous reports of aneurysms located at the origin of the accessory middle cerebral artery. The relevant literature is briefly reviewed.     

Histological and morphometric observations on the reticular fibers in the arterial beds of patients with ruptured intracranial saccular aneurysms

Histological and morphometric studies on the collagenous, reticular, and elastic fibers of the tunica media were performed on the middle cerebral and brachial arteries of patients with ruptured intracranial saccular aneurysms and controls. There was no difference between aneurysm patients and controls in the amount of collagenous and elastic fibers. The amount of reticular fibers was, however, reduced about 35% in aneurysm patients within both the middle cerebral artery (P less than 0.01) and the brachial artery (P less than 0.02). The reticular fibers were irregularly distributed and often appeared shorter and coarser than normally. The observations point to a generalized abnormality of the arterial bed in some patients with rupture of saccular aneurysms.     

Morphometrical analyze of the middle cerebral artery system at the 13-15 weeks fetuses

Tele-encephalization process is accompanied by the appearance and progressive complication of the middle cerebral artery system. The aim of our study is to analyze the morphometrical parameters of the middle cerebral artery branches in the beginning of the edification of its system. We used 162 cerebral hemispheres from 88 fetuses aged of 13-15 weeks. Middle cerebral artery system was injected with a gelatin-China ink mixture and images recorded by means of a Zeiss surgical microscope. Parameters evaluation (length, proximal and distal diameters, external surface, volume, angles of bifurcation) was realized with KS-300 program. At this early age middle cerebral artery system has only 4-5 generations of branches usually resulting from acute angle bifurcations.