Daniel Reizine

Real-time magnetic resonance-guided laser thermal therapy for focal metastatic brain tumors.

OBJECTIVE We report the initial results of a pilot clinical trial exploring the safety and feasibility of the first real-time magnetic resonance-guided laser-induced thermal therapy of treatment-resistant focal metastatic intracranial tumors. METHODS Patients with resistant metastatic intracranial tumors who had previously undergone chemotherapy, whole-brain radiation therapy, and radiosurgery and who were recused from surgery were eligible for this trial. Under local anesthesia, a Leksell stereotactic head frame was used to insert a water-cooled interstitial fiberoptic laser applicator inside the cranium. In the bore of a magnetic resonance imaging (MRI) scanner, laser energy was delivered to heat the tumor while continuous MRI was performed. A computer workstation extracted temperature-sensitive information to display images of laser heating and computed estimates of the thermal damage zone. Posttreatment MRI scans were used to confirm the zone of thermal necrosis, and follow-up was performed at 7, 15, 30, and 90 days after treatment. RESULTS In all cases, the procedure was well tolerated without secondary effect, and patients were discharged to home within 14 hours after the procedure. Follow-up imaging showed an acute increase in apparent lesion volume followed by a gradual and steady decrease. No tumor recurrence within thermal ablation zones was noted. CONCLUSION In this ongoing trial, a total of four patients have had six metastatic tumors treated with laser thermal ablations. Magnetic resonance-guided laser-induced thermal therapy appears to provide a new, efficient treatment for recurrent focal metastatic brain disease. This therapy is a prelude to the future development of closed-head interventional MRI techniques in neurosurgery.

Laser thermal therapy: Real‐time MRI‐guided and computer‐controlled procedures for metastatic brain tumors

We report the final results of a pilot clinical trial exploring the safety and feasibility of real‐time magnetic resonance‐guided laser‐induced thermal therapy (MRgLITT) for treatment of resistant focal metastatic intracranial tumors.

Spinal dural arteriovenous malformations with perimedullary drainage. Indications and results of surgery in 30 cases.

Summary70 patients were treated for spinal dural arteriovenous fistula in the same centre, during a period of 10 years. Conus medullaris and cauda equina syndromes were observed in all patients as the clinical stereotyped presentation.Diagnosis was based on myelography in the first instance and then on angiography.40 patients were treated by intravascular neuroradiological embolization, whereas the other 30 were operated on. Surgery was proposed because embolization was contraindicated (7 cases of hazardous catheterisation) of inefficient (23 cases=38%).The results of the operative series are presented, and compared with those of embolization. Improvement was observed in 50% of the 20 patients with follow up, but a complete recovery to an asymptomatic state was never obtained. For the other patients (47%) complete stabilization of the disease could be obtained, whereas in one of the patients (3%), who was operated upon because of failure of embolization, surgery was also completely ineffectual. The long-term results of patients treated surgically are comparable with those patients efficiently embolized.5 patients of the operative series were submitted to MRI before and after surgery: the results and the place of MRI are discussed.

Vascular Abnormalities in the Neck Associated with Intracranial Aneurysms

In 102 cases of ruptured intracranial aneurysms, the cervical as well as the cranial areas were explored by angiography. Loops in the course of the cervical vessels were present in 28 patients; features of fibromuscular dysplasia were present in 31 patients; and in 50 patients, no abnormalities were observed. In 7 patients, both cervical anomalies were present. Loops were associated with single aneurysms (95%), located primarily on the anterior communicating artery (76%), predominantly in men (M/F = 1.6). Aneurysms with fibromuscular dysplasia affected women more than men (F/M = 7), were frequently multiple (58%), and were located mainly on the intracranial part of the internal carotid and vertebral arteries (51%). These data suggest new concepts of aneurysm formation from inherited diseases and should permit the detection of some aneurysms before rupture.

Endovascular treatment of vertebral arteriovenous fistulas in twenty-two patients

Twenty-two cases of vertebral arteriovenous fistulas treated by embolization are reported. Although such fistulas are usually asymptomatic they may be occasionally responsible for tinnitus. Neurologic complications are exceptional. Spontaneous fistulas have been found predominantly in the C1-C2 region (9 of 13 cases), while post-traumatic fistulas were located in the C5-C6 region and were often iatrogenic in origin (7 of 9 cases). In 17 cases embolization caused definitive closure of the fistula, while the vertebral artery remained patent. In three patients it was also necessary to close the vertebral artery in order to occlude the fistula. In two instances, endovascular management failed to obliterate the fistula. At present, endovascular treatment is the simplest and one of the least aggressive therapeutic approaches to vertebral arteriovenous fistulas.

Pyogenic parenchymatous and nidus infection after embolization of an arteriovenous malformation: An unusual complication. Case report

SummaryInfectious complications of cerebral angiography and of therapeutic angiographic procedures are very seldom reported. The case of an infected embolized arteriovenous malformation (AVM) by staphylococcus aureus is reported. Abscess formation became manifest seven months after the endovascular procedures. Antibiotherapy was initially started after puncturing the abscess, but finally the cure of the lesion could only be obtained by radical excision of the infected and embolized AVM, as if the persisting embolization material was promoting the infection. The modalities of infection after cerebral endovascular procedures are discussed.

Direct Arteriovenous Fistula of the External Carotid Artery: Treatment with Detachable Balloon

Direct arteriovenous fistulas originating from the terminal branches of the external carotid artery constitute a rare form of facial vascular disorders. They are usually well tolerated and do not grow. Surgical removal or ligation of the fistula may be hazardous to the facial nerve or lead to aesthetic insult. Based on our experience in five cases treated successfully with detachable balloons, we propose this technique as an alternative to surgery.

Phase contrast magnetic resonance of the spinal cord: Preliminary results in spinal cord arterio-venous malformations

SummaryIn spite of the recent advances in neuroradiology including the CT scan and the spin-echo-magnetic resonance (MR), accurate diagnosis of arteriovenous malformations (AVMs) involving the spinal cord is still based on selective angiography. This last procedure is invasive and needs to be repeated during the follow up. Phase contrast angio MR was performed with a 0.5 Tesla unit on 12 patients with an AVM involving the spinal cord (7 intramedullary AVMs, 4 perimedullary fistulas, and 1 dural fistula with perimedullary venous drainage); 4 of these were investigated before and after treatment. Angio MR showed abnormal vascular patterns within the spinal canal in all cases, without distinguishing between arteries and veins; the nidus of the intramedullary AVMs was displayed in all cases. Angio MR provided images of the whole AVMs comparable to the angiographic pictures, in contrast to the spin-echo MR, which provided only discontinued images of the vessels. The efficient range of velocity providing images varied, according to the type of the malformation (slow for dural fistulas, rapid for intra-medullary AVMs). In the 4 patients investigated after treatment, comparison of the images obtained before and after treatment permitted assessment of the degree of occlusion of the malformation. Finally, angio MR as a complement of spin-echo MR can now be used as a reliable tool for detection of spinal cord AVMs, assessing the indication for angiography, and, furthermore, it can probably replace most of the postoperative control angiographies. The value of the efficient imaging velocity is disputable but seems to depend on the haemodynamic characteristics of the malformation and may then serve as a guide to angiography.

Endovascular Treatment of Arteriovenous Fistulas Arising from Branches of the Subclavian Artery

PURPOSE The goal of this study was to evaluate the role of endovascular techniques in the treatment of arteriovenous fistulas (AVFs) in the subclavian region. PATIENTS AND METHODS Since 1984 six patients with AVFs arising from branches of the subclavian artery have been treated. All AVFs were of iatrogenic origin (five venous punctures and one pacemaker insertion). Two patients had cardiac insufficiency, three had a bruit, and one had upper extremity venous hypertension. Angiographically, four of the AVFs were located on the thyrocervical trunk and two were on the internal mammary artery. RESULTS All fistulas were treated by means of endovascular occlusion with a detachable balloon, with full resolution of symptoms. One AVF recurred after a balloon deflated prematurely. The patient was treated again and was subsequently cured. No other complications were associated with treatment. CONCLUSION Endovascular balloon occlusion of AVFs in the subclavian region is a simple, effective, and safe method that eliminates the need for surgery. It should be the method of choice for treatment of these lesions.

Economic Assessment of Magnetic Resonance Imaging for Inpatients: Is It Still Too Early?

This economic assessment of the implementation of magnetic resonance imaging (MRI) in a French hospital examines data on the diagnostic resources used in neurology and neurosurgery before and after MRI was available. Given a similar patient population and case mix, there was no change in the resources used other than the addition of MRI. So far, MRI appears to be a complement to, and not a substitute for, other imaging techniques used in neuroradiology. The focus of this work is purely economic; its conclusions do not challenge the major scientific contributions of MRI.