Noninvasive three-dimensional computed tomographic angiography in preoperative detection of intracranial arteriovenous malformations

Obejctive To assess the value of noninvasive three dimensional computed tomographic angiography (3D CTA) in preoperative detection of intracranial arteriovenous malformations (AVMs) Methods A prospective evaluation at a single institute over a 2 year period included 23 patients suspected of intracranial AVMs All patients underwent 3D CTA and digital subtraction angiography (DSA) Results from both procedures were compared Results 3D CTA imaging provided excellent visualization of intracranial AVMs The false positive error and false negative error were zero in our sample The details of arterial supply (numerical measure, orientation, caliber and routing) and vascular nidus (size, morphosis and location) provided by 3D CTA images were the same as DSA and the details of venous drainage were an approximate match Additionally, 3D CTA can depict tridimensional anatomical information for AVMs and their relationship to adjacent structures, a function not possible with DSA This assisted the surgeons in making better surgical planning and reduced trauma As a non invasive course, there were no related complications in the course of 3D CTA processing Conclusions DSA is still regarded as the gold standard for intracranial AVMs detection The modality of 3D CTA is accurate, noninvasive, nearly risk free and low price; we could routinely use it instead of or as a supplement to DSA, in the preoperative detection of suspected intracranial AVMs and postoperative radiological follow up 3D CTA adds tridimensional aspect and assists the surgeon in a the more accurate therapeutic scheme Preliminary data suggest that 3D CTA is playing a favorable role in the assessment of patients with intracranial AVMs

Surgical strategy for cerebral arteriovenous malformation with acute hemorrhage

BACKGROUND： Presently, there have been craniocerebral operation, interventional embolization,stereotactic radiotherapy and other methods in treating cerebral arteriovenous malformation （AVM）.However, the standard of different therapeutic regimens of cerebral AVM at the acute stage of hemorrhage has not been completely identified.OBJECTIVE： To observe the clinical characteristics and therapeutic effects of AVM at the acute stage of hemorrhage in patients, and to analyze corresponding therapeutic strategies.DESIGN： Non-randomized clinical observation.SETTING： Department of Neurosurgery, Foshan First People＇s Hospital, Sun Yat-sen University.PARTICIPANTS： Forty-six patients with cerebral AVM complicated by hemorrhage admitted to Department of Neurosurgery, Foshan First People＇s Hospital between January 1999 and December 2006,were involved in this study. All the patients were confirmed as cerebral AVM complicated by hemorrhage by brain angiography or/and postoperational pathology. The involved patients, 32 males and 14 females,averaged 25 years old, ranging from 6 to 62 years. Informed consents of therapeutic items were obtained from the relatives of all the patients.METHODS： ①On admission, skull CT and brain angiography were conducted in the involved subjects. ②The therapeutic method was confirmed according to the consciousness, hematoma region, hematoma volume,imageological results following comprehensive analysis： DSA examination was permitted to identify the size and position of abnormal vessel mass, and the distribution of feeding artery and draining vein. Craniocerebral operation was carried out as early as possible in patients with severe or progressive conscious disturbance, in which most of hematoma with obvious occupied effect or cerebral hernia was located in lobe of brain. The primary thing was to clean intracerebral hematoma for in time decompression. According to different situations, corresponding therapeutic measures were used for resecting abnormal vessel mass, and the treatments of patients were observed. ③The therapeutic effects were assessed following Glasgow outcome scale（GOS） at 3 months after hemorrhage.MAIN OUTCOME MEASURES： ①The examination results of skull CT and brain angiography of patients on admission. ②Treatment of patients. ③GOS results at 3 months after hemorrhage.RESULTS： Forty-six patients were involved, and all of them participated in the final analysis. ① Examination results of skull CT and brain angiography： Bleeding part： frontal lobe in 7 cases, parietal lobe 15, temporal lobe 19, occipital lobe 3, cerebellar hemisphere 2, and hemorrhage rupturing into ventricle 10. Haematoma volume： small volume of hematoma （〈20 mL） in 4 cases, moderate volume of hematoma （20 - 50 mL） 14, large volume of hematoma （ 50 - 80 mL） 21, great volume of hematoma （〉80 mL） 7; Abnormal vessel mass： Among 17 patients undergoing aortocranial angiography, abnormal vessel mass was found in 16 patients, including cortex 13 patients, basal ganglia and thalamencephalon（deep part） 2 patients, and posterior cranial fossa 1 patient. The size of abnormal vessel mass： small （〈3 cm） 4 patients, moderate （3 -6 cm） 9 patients, and large （〉6 cm） 3 patients. The type of feeding artery： perforating branch blood-supply 1 patient, cortical branch blood supply 13 patients, mixed branch blood supply 2 patients. The type of draining vein： cortical draining （superficial part） 10 patients, deep part draining 2 patients, and mixed draining 4 patients. ② Treatment condition： Among 17 patients undergoing brain angiography followed by craniocerebral operation, hematoma was removed and AVM was completely resected in 12 patients, hematoma was removed and AVM was partially resected in 3 patients, and only hematoma was resected in 2 patients; Among 24 patients undergoing emergent craniocerebral operation, hematoma was removed and AVM was completely resected in 5 patients, hematoma was removed and AVM was partially resected in 9 patients, and only hematoma was resected in 10 patients; Expectant treatment was carried out in the early stage in 5 patients. When disease condition was stable, AVM resection was separately or complicatedly conducted in 13 patients, embolization in 4 patients, and γ - radiotherapy in 5 patients. ③GOS： 5 patients died in postoperative complications, and among the other patients, 19 had moderate or had not functional impairment, 13 had moderate disability, 6 had severe disability, 2 were vegetative state, and 2 died. ④Post-operative re-examination of brain angiography： Among 16 patients undergoing AVM, vessel mass disappeared in 9 patients.CONCLUSION： Good therapeutic effects can be obtained by choosing proper therapeutic regimen according to clinical and imageological characteristics of patients with arteriovenous malformation complicated by hemorrhage at the acute stage.

Role of activin receptor-like kinase 1 in vascular development and cerebrovascular diseases

Activin receptor-like kinase 1(ALK1)is a transmembrane serine/threonine receptor kinase of the transforming growth factor beta(TGFβ)receptor superfamily.ALK1 is specifically expressed in vascular endothelial cells,and its dynamic changes are closely related to the proliferation of endothelial cells,the recruitment of pericytes to blood vessels,and functional differentiation during embryonic vascular development.The pathophysiology of many cerebrovascular diseases is today understood as a disorder of endothelial cell function and an imbalance in the proportion of vascular cells.Indeed,mutations in ALK1 and its co-receptor endoglin are major genetic risk factors for vascular arteriovenous malformation.Many studies have shown that ALK1 is closely related to the development of cerebral aneurysms,arteriovenous malformations,and cerebral atherosclerosis.In this review,we describe the various roles of ALK1 in the regulation of angiogenesis and in the maintenance of cerebral vascular homeostasis,and we discuss its relationship to functional dysregulation in cerebrovascular diseases.This review should provide new perspectives for basic research on cerebrovascular diseases and offer more effective targets and strategies for clinical diagnosis,treatment,and prevention.

Pre-and postoperative changes of regional cortical cerebral blood flow in patients with cerebral arteriovenous malformation

Objective To investigate pre- and postoperative changes of regional cerebral cortical blood flow in patients with cerebral arteriovenous malformation. Method Twenty-two adult patients with arteriovenous malformation(AVM) were recruited into this study at Beijing Tiantan Hospital from September 2001 to May 2002. Eight patients had giant cerebral AVM and the other 14 had a small one. Cortical cerebral blood flow (CBF) was measured by laser Doppler flowmetry (LDF) before and after AVM resections. After surgery,the probe of LDF was implanted adjacent to the area of AVM and monitored for 24 hours.Results CBF increased significantly after the resection in all patients regardless of AVM size. In patients with small AVM,CBF returned to the baseline level within 4 hours,but in patients with giant AVM,CBF remained high even after 24 hours.Conclusions Monitoring CBF is helpful to understand pre- and postoperative changes of regional cortical CBF in patients with cerebral AVM.