3D angiography. Clinical interest. First applications in interventional neuroradiology. (1/816)

3D angiography is a true technical revolution that allows improvement in the quality and safety of diagnostic and endovascular treatment procedures. 3D angiography images are obtained by reconstruction of a rotational angiography acquisition done on a C-arm (GE Medical Systems) spinning at 40 degrees per second. The carotid or vertebral selective injection of a total of 15 ml of non-ionic contrast media at 3 ml/sec over 5 seconds allows the selection of the "arterial phase". Four hundred sixty 3D angiographic studies were performed from December 1996 to September 1998 on 260 patients and have been analyzed in MIP (Maximum Intensity Projection) and SSD (Shaded Surface Display) views. The exploration of intracranial aneurysms is simplified and only requires, for each vascular axis, a biplane PA and Lateral run followed by a single rotational angiography run. The 3D angiography image is available on the workstation's screen (Advantage Workstation 3.1, GE Medical Systems) in less than 10 minutes after the acquisition of the rotational run. It therefore allows one to analyze, during the intervention, the aneurysm's angioarchitecture, in particular the neck, and select the best therapeutic technique. When endovascular treatment is the best indication, 3D angiography allows one to define the optimal angle of view and accurately select the microcoils dimensions. 3D angiography replaces the multiple oblique views that used to be required to analyze the complex aneurysms and therefore allows a reduction of the total contrast medium quantity, the patient X-ray dose and the length of the intervention time which is a safety factor. Also, in particular for complex cases, it brings additional elements complementing the results of standard 2D DSA and rotational angiograms. In the cervical vascular pathology, 3D angiography allows for a better assessment of the stenosis level and of dissection lesions. Our current research activities focus on the matching without stereotactic frame between 3D X-ray angiography and volumetric MR acquisition, which should allow us to improve the treatment of intracerebral arterio-venous malformations (AVMs).  (+info)

Successful radiosurgical treatment of arteriovenous malformation accompanied by venous malformation. (2/816)

We present a patient with a rare cerebrovascular malformation consisting of a typical arteriovenous malformation (AVM) with a nidus and a venous malformation (VM) in a single lesion. The AVM component was successfully obliterated by radiosurgery, whereas the VM was completely preserved. Radiosurgery can be an effective treatment technique for treating this type of malformation because it allows targeted obliteration of the AVM yet carries a low risk of damaging the venous drainage toward and away from the VM.  (+info)

Angiographic abnormalities in progressive multifocal leukoencephalopathy: an explanation based on neuropathologic findings. (3/816)

BACKGROUND AND PURPOSE: Progressive multifocal leukoencephalopathy (PML) is typically occult at angiography and fails to enhance on MR images. After observing angiographic abnormalities characterized by arteriovenous shunting and pathologic parenchymal blush in patients with AIDS-related PML, often in the absence of contrast enhancement on MR images, we hypothesized that there might be distinct changes in the cerebral microvasculature that account for the reduction in vascular transit time (arteriovenous shunting) in the absence of blood-brain barrier dysfunction. METHODS: The imaging studies and neuropathologic specimens of six patients with biopsy-proved PML were reviewed retrospectively. In all patients contrast-enhanced MR imaging and CT, followed by cerebral angiography, were performed before stereotactically directed biopsy. The angiograms were evaluated for the presence of vascular displacement, pathologic parenchymal blush, arteriovenous shunting, and neovascularity. The CT and MR studies were reviewed for the presence of enhancement of the PML lesions. Biopsy specimens were examined for the presence of necrosis, perivascular inflammation, and neovascularity. RESULTS: All patients had oligodendrocytic intranuclear inclusions diagnostic of PML, together with perivascular inflammation and neovascularity to a varying extent; no other neuropathologic processes were identified. Angiographic abnormalities, characterized by a pathologic parenchymal blush and arteriovenous shunting, were identified in four of the six patients. In only one of these cases, however, was abnormal enhancement identified on cross-sectional imaging studies (MR and CT), and this patient had florid perivascular inflammatory infiltrates histologically. CONCLUSION: The pathologic parenchymal blush and arteriovenous shunting seen angiographically in some patients with PML reflect small-vessel proliferation and perivascular inflammatory changes incited by the presence of the JC virus in infected oligodendrocytes.  (+info)

Microsurgical resection of incompletely obliterated intracranial arteriovenous malformations following stereotactic radiosurgery. (4/816)

Radiosurgery is effective in obliterating small arteriovenous malformations (AVMs), but less successful in thrombosing larger AVMs. This study reviewed patients who underwent surgical resection of their large AVMs following failed radiosurgical obliteration. AVMs from 36 patients (aged 7 to 64 years, mean 29.9) were surgically resected 1 to 11 years after radiosurgery. Initial AVM volumes were 0.7 to 117 cm3 (mean 21.6 cm3), and radiosurgical doses ranged from 4.6 to 45 Gray equivalent (GyE) (mean 21.1 GyE). Thirty AVMs (83%) were located in eloquent tissue. Venous drainage was deep (14), superficial (13), or both (9). Spetzler grades were II (2), III (12), IV (18), and V (4). Nine patients suffered rehemorrhage after radiosurgery but prior to surgery, while three patients developed radiation necrosis. Twenty-seven patients underwent endovascular embolization prior to surgery. During microsurgical resection, the AVMs were found to be significantly less vascular and more easily resected, compared to AVMs in patients who had not received radiosurgery. Histology showed endothelial proliferation with hyaline and mineralization in vessel walls. Partial or complete thrombosis of some AVM vessels, and evidence of vessel and brain necrosis were noted in many cases. Clinical outcome was excellent or good in 34 cases, with two patients dying of rebleeding from residual AVM. Five patients were neurologically worse following microsurgical resection. Final outcome was largely related to the pretreatment grade. Radiosurgery several years prior to surgical resection appears useful in treating unusually large and complex AVMs.  (+info)

Surgery for deeply seated arteriovenous malformation: with special reference to thalamic and striatal arteriovenous malformation. (5/816)

Surgery for deeply seated arteriovenous malformation (AVM) is controversial because stereotactic irradiation is applicable to the lesion. We have, however, experienced 30 deeply seated AVMs treated by direct surgery and/or endovascular treatment. The present study shows profiles of those patients and results of surgery. They include AVM in the thalamus in 12 cases, striatum in four cases, paraventricular area in five cases, medial temporal lobe in three cases, intraventricular area in three cases, and other regions in three cases. They were treated by surgery alone in 23 cases, embolization followed by surgery in four cases, and embolization alone in three cases. AVM in the mediodorsal thalamus and fornix (5 cases) was best treated by transcallosal approach. Venous aneurysm was commonly found in the AVM of this region and was a good navigator to the AVM. Pulvinar AVM was accessible through posterior interhemispheric approach (2 cases). None of these cases had additional neurological deficits. Cadaver dissection was useful for acquisition of surgical approach. Striatal AVM was approached through hematoma cavity with minimal manipulation to the surrounding structures, yet two of four cases showed progression of their weakness. The present study indicates that thalamic AVM can be approached surgically with careful selection of the approach. On the other hand, striatal AVM is not a good candidate for direct surgery and better treated by stereotactic irradiation.  (+info)

Complications of angioma surgery--personal experience in 191 patients with cerebral angiomas. (6/816)

In the last years, treatment decisions of arteriovenous malformations (AVMs) were influenced by the improvement of stereotactic radiosurgery and were revolutionized by development of embolization techniques. The aim of this report was to examine the results, effectiveness, and complications associated with angioma surgery. 191 patients with AVMs were operated by the first author between 1981 and 1996. Angioma localization was distributed as follows: frontal 51 (26.7%), temporal 44 (23%), parietal 45 (23.6%), and occipital 24 (12.6%). Twelve (6.3%) AVMs were located in the cerebellum and 15 (7.9%) in other deep regions. Twenty-nine (15.2%) AVMs were associated with single or multiple aneurysms. The preoperative symptoms were hemorrhage (50.3%), seizure (33.5%), headache (23.0%), focal neurological deficits (12.6%), and other minor symptoms. In 9.9%, the disease remains preoperatively asymptomatic. Based on the Spetzler/Martin scale (S/M), 38 patients were grade I, 39 grade II, 52 grade III, 39 grade IV, and 23 grade V. The following severe complications were observed: postoperative hemorrhage in 13 (6.8%), infection in six (3.1%), infarction in two (1.0%), and death in three (1.6%). The risk for postoperative complications was related to the preoperative S/M grade of the AVM. Severe complications only occurred in AVM grades IV and V. In 62 patients with grade IV and V AVM, three patients died (4.8%) and 12 showed neurological deterioration (19.4%). Only 3/129 (2.3%) patients with grade I-III AVM deteriorated postoperatively. No severe complications were observed in preembolized and recently operated patients. Microsurgical management of cerebral AVMs seems to be a reasonably safe procedure especially in grade I-III AVMs, with a mortality of less than 2%. With enough experience and exact attention to detail, the experienced neurosurgeon can remove many of these AVMs with a minimum of risk to the affected patient. Although hemorrhage from an AVM can be disabling or deadly, the course in many nonoperated high-grade AVMs (S/M grades IV and V) can be quite benign, if compared with their surgical risk. This may justify conservative treatment or treatment with radiosurgery in some high-grade (S/M grades IV and V) angiomas, especially in elderly patients.  (+info)

Decreased BOLD functional MR activation of the motor and sensory cortices adjacent to a glioblastoma multiforme: implications for image-guided neurosurgery. (7/816)

A patient with a glioblastoma multiforme and mild sensorimotor deficits had significantly less activation of the motor and sensory cortices on the side with the tumor than on the contralateral side on blood oxygen level-dependent (BOLD) functional MR images. This difference, which may be due to pressure effects or loss of vascular autoregulation, should be considered in preoperative planning in which BOLD functional MR imaging is used to identify eloquent cortices to be avoided during brain tumor surgery.  (+info)

Stereotactic thalamotomy in the treatment of essential tremor of the upper extremity: reassessment including a blinded measure of outcome. (8/816)

The effectiveness of high frequency stimulation of the thalamic nucleus ventralis intermedius (Vim-HFS) for treatment of tremor has been studied by blinded assessment. The effectiveness of thalamotomy for essential tremor of the upper extremity by use of a blinded measure of outcome is now reported. Thalamotomy was performed in 21 patients (three operated on bilaterally) with medically intractable, essential tremor. Assessments of function, handwriting/drawing, and tremor amplitude were done before and at 3 and 12 months after surgery. The handwriting/drawing score was rated by a neurologist blinded to patient identity, laterality, and operative status. By comparison with baseline, both the total functional score and the total score from blinded assessment of handwriting/drawing improved significantly at 3 and 12 months after surgery. The two scores were significantly correlated, suggesting that the blinded assessment is a good predictor of a total disability from tremor. Complications after unilateral thalamotomy included transient dysarthria, permanent perioral numbness, and permanent mild disequilibrium in one patient each. Permanent mild dysarthria occurred in two of three patients operated bilaterally. Thus a blinded assessment of outcome establishes that unilateral thalamotomy is an effective, safe procedure for the treatment of essential tremor.  (+info)