Faculty Bibliography

The endovascular treatment of wide-necked intracranial aneurysms is evolving. We report our initial experience in treating seven wide-neck intracranial aneurysms by using a new self-expanding stent, the Neuroform, in combination with a new generation of coils that incorporate a self-expandable hydrophilic lining, the HydroCoil.

Aneurysmal subarachnoid hemorrhage in a neonate is exceedingly uncommon. The authors report the case of a neonate with a large anterior communicating artery aneurysm, accessory left middle cerebral artery aneurysm, and left internal carotid artery (ICA) fusiform aneurysm. The neonate suffered from occlusion of the left ICA and aneurysm rupture. The large aneurysm was treated with detachable coils and the patient made a significant recovery. Of the 15 case reports of cerebral aneurysms in neonates that have been published, none has contained a description of multiple aneurysms or a discussion of endovascular treatment.

We simultaneously injected both internal carotid arteries (ICAs) during 3D rotational digital subtraction angiography in a patient with a ruptured anterior communicating artery (Acom) aneurysm and vasospasm. Shaded surface display (SSD) images from this acquisition provided more anatomic detail than did SSD images created from individual ICA 3D rotational digital subtraction angriography. In the evaluation of complex Acom aneurysms, this technique can facilitate the choice of optimal working projections for safer aneurysm coiling.

BACKGROUND AND PURPOSE: The management of thrombus formation during coil placement in an intracranial aneurysm is important in minimizing periprocedural morbidity and mortality. We report on seven cases in which the primary treatment for thrombus formation during such coil placement was intra-arterial abciximab infusion. METHODS: Clinical and radiologic records of 100 consecutive patients who underwent coil placement in intracranial aneurysms at our institution during a 1-year period were reviewed. We identified seven cases (four ruptured aneurysms, three unruptured aneurysms) in which thrombus formation occurred during the procedure. RESULTS: Intra-arterial abciximab infusion, up to 5 mg, completely dissolved the thrombus in four of seven patients and almost completely dissolved it in two. In one patient with distal emboli, recanalization was not achieved. In two patients, an intravenous bolus of abciximab without 12-hour infusion was also given adjunctively. In one patient, leakage of contrast material occurred; this was related to the intra-arterial infusion. Clinically, no new neurologic deficits were directly related to the intra-arterial abciximab infusion. Six patients had good clinical outcome, and one patient died. CONCLUSION: Relatively low-dose, intra-arterial abciximab infusion can immediately dissolve an acute thrombus that forms during intracranial aneurysm coil placement. Although neither the optimal dose of intra-arterial abciximab nor the need to supplement the intra-arterial infusion with intravenous administration was established, we preliminarily found that low-dose intra-arterial abciximab infusion may be relatively effective and safe in this setting, even in patients with acute subarachnoid hemorrhage

Despite its reduced use since the advent of magnetic resonance imaging, the high cervical myelogram remains a common diagnostic test in the evaluation of patients whose symptoms suggest cervical stenosis. We report a case of subarachnoid hematoma, hydrocephalus, and aseptic meningitis after a high cervical myelogram. A 52-year-old woman presented with headache, slurred speech, worsened neck pain and stiffness, and diffuse extremity weakness leading to gait instability beginning several hours after a cervical myelogram. Computed tomography (CT) scan revealed a C1-C2 hematoma below the dura, blood in the fourth and lateral ventricles, and hydrocephalus. An external ventricular drain was placed, and cerebrospinal fluid profile was consistent with aseptic meningitis. A suboccipital craniectomy and C1-C2 laminectomies were performed, followed by a C1-C2 durotomy, which revealed a large subarachnoid blood clot in the region of the cisterna magna extending down to the upper aspect of C2, which was evacuated by incising the arachnoid. In the midline at C1, an active source of intramedullary arterial bleeding on the dorsal surface of the spinal cord was coagulated. Spinal subarachnoid hematoma is a rare complication of high cervical myelogram. The extension of blood into the ventricular system with associated hydrocephalus has never been previously reported after myelography. Thus, severe persistent pain after cervical myelography should be evaluated by CT scans of the brain and cervical spine.

The treatment of ruptured cerebral aneurysms in patients presenting with vasospasm remains a particular challenge. The authors treated two patients harboring Hunt and Hess Grade 1 subarachnoid hemorrhages from middle cerebral artery (MCA) aneurysms associated with severe local angiographically demonstrated yet asymptomatic vasospasm on presentation. Because both aneurysms had wide necks and were located at the MCA bifurcation, they were believed to be anatomically suitable for microsurgical clip application. Severe M, vasospasm was believed to be a relative contraindication to open surgery, however. An intentionally staged endovascular and microsurgical treatment strategy was planned in each patient. Partial coil occlusion of the aneurysmal dome was performed to prevent the lesion from rebleeding and was followed by balloon angioplasty of the spastic vessel. Early treatment of the severe spasm appeared to prevent significant delayed neurological ischemic deficit. Following resolution of the vasospasm, definitive clipping of the aneurysms was performed on Day 13 post embolization. One patient had a good clinical recovery and was discharged without neurological deficit. The other patient's hospital course was complicated by the occurrence of a postoperative posterior temporal infarct requiring partial temporal lobectomy, although she eventually had a good recovery with only a small visual field deficit. Based on data obtained in these two patients, one can infer that ruptured wide-necked MCA aneurysms associated with severe local vasospasm may best be treated using a staged combined treatment plan. Delayed clip application might be performed more safely 4 to 6 weeks postocclusion, or later, than at 2 weeks

PURPOSE/OBJECTIVE:To define radiographic dose-response relationships for proton radiosurgery using a rat brain model. METHODS AND MATERIALS/METHODS:A group of 23 rats was treated with Bragg peak proton beam irradiation involving the right hippocampus. Single doses of 5, 12, 20, 30, 60, 90 and 130 cobalt gray equivalents (CGE) were delivered to groups of 3 animals using single fraction technique. One extra animal was included at the 130- and 30-CGE doses. Animals were imaged using a standard 1.5-tesla GE Signa MRI. A 3-inch surface coil was employed to obtain T1-weighted sagittal images (TR 600 and TE 30) and dual echo T2-weighted coronal images (TR 3,000 and TE 30/90). Animals were imaged at 1.5, 3, 4.5, 6 and 9 months. Volumetric analysis with custom software was done to evaluate areas of increased signal on T2-weighted images, and signal change versus time curves were generated. Gadolinium-enhanced T1-weighted imaging was also done at the 9-month time point to further evaluate tissue injury. The development of hydrocephalus was also examined. RESULTS:Peak tissue injury was greater and occurred earlier with higher versus lower doses of radiation. Statistically significant differences were seen between the 130- and 90-CGE animals and between the 90- and 60-CGE animals (p < 0.0016) using ANOVA. Signal changes can be seen in at least 1 of the animals at 20 CGE. The largest volume of tissue enhancement at 9 months was seen in animals at 60 CGE, which may represent an intermediate zone of tissue injury and gliosis compared with greater tissue loss at higher doses and less injury at lower doses. Hydrocephalus developed first in the untreated hemisphere in 130- and 90-CGE animals as a result of mass effect while it occurred at a later time in the treated hemisphere in lower-dose animals. CONCLUSIONS:Following single-dose proton radiosurgery of rat hippocampus, serial MRIs show T2 signal changes in animals ranging from 130 down to 20 CGE as well as the development of hydrocephalus. Dose-effect relationships using proton radiosurgery in rats will be a helpful step in guiding further studies on radiation injury to brain tissue.