Cerebral sinus thrombosis, although uncommon, can be lethal if not recognized and treated quickly. Systemic heparin has become the treatment standard of care; however, some patients' conditions continue to deteriorate even while taking heparin. Endovascular techniques for thrombolysis have continued to evolve. The authors present a case of cerebral sinus thrombosis treated with a combination of mechanical and chemical intrasinus thrombolysis.
Kim L. Rickert, Phillip D. Purdy, and Babu Guai Welch
Phillip D. Purdy, H. Hunt Batjer, and Duke Samson
✓ Endovascular embolization procedures have undergone dramatic evolution and improvement in recent years. Despite these advances, controversy remains regarding the optimal role of these procedures in treating cerebral arteriovenous malformations (AVM's) and whether their purpose should be as a presurgical adjunct or as primary therapy. This controversy risks fragmentation between disciplines in the broader efforts to improve management of cerebrovascular disorders.
The authors report seven cases of life-threatening hemorrhages that occurred during staged invasive therapy for AVM's which illustrate the value of a unified team approach to optimize patient care. Each patient underwent at least one embolization procedure using polyvinyl alcohol particles, followed in two cases by the occlusion of proximal feeding vessels by platinum microcoils and in one case by the attempted detachment of an endovascular balloon. In three patients, catheter penetration into the subarachnoid space resulted in subarachnoid hemorrhage. One patient suffered rupture of a large feeding vessel during balloon inflation. The final three patients sustained intracranial hemorrhage 2 hours, 8 hours, and 5 days, respectively, following embolization. All but two patients underwent emergency craniotomy at the time of the complication. These cases underscore the advantages of interdisciplinary management optimizing decision-making and providing expeditious care when life-threatening complications develop.
Phillip D. Purdy, H. Hunt Batjer, Richard C. Risser, and Duke Samson
✓ The authors report their experience with surgical resection of 108 previously embolized arteriovenous malformations (AVM's). Embolization was performed via only transfemoral catheterization in 70 lesions and via the surgical exposure of feeding vessels in 32. The remaining six patients were referred for resection following silicone sphere embolization elsewhere. Materials used included polyvinyl alcohol (PVA) foam, platinum microcoils, detachable silicone balloons, surgical silk, a mixture of 33% ethanol and microfibrillar collagen, and isobutyl cyanoacrylate (IBCA). It is believed that proximal arterial occlusion with balloons is an inferior choice for preresection embolization, because the technical difficulty of placement is high and the nidus of the AVM is unaffected. Vascular coagulation and section and AVM retraction are more difficult with IBCA; therefore, this is also considered an inferior choice.
Among the materials studied, the combination of PVA for distal occlusion and microcoils for proximal occlusion appears to be the superior choice. Fewer complications (stroke or hemorrhage) are seen when intraarterial Amytal (amobarbital) testing is used to guide the embolization. Data regarding toxicity, oncogenicity, and vascular metabolism or recanalization associated with PVA, IBCA, and n-butyl cyanoacrylate are reviewed.
Roberto C. Heros
Christopher L. Taylor, Thomas A. Kopitnik Jr., Duke S. Samson, and Phillip D. Purdy
Object. The records of 30 patients with posterior cerebral artery (PCA) aneurysms treated during a 12-year period were reviewed to determine outcome and the risk of visual field deficit associated with PCA sacrifice.
Methods. Clinical data and treatment summaries for all patients were maintained in an electronic database. The Glasgow Outcome Scale (GOS) and modified Rankin Scale (mRS) scores were determined by an independent registrar. Visual field changes were determined by review of medical records. Twenty-eight patients were treated with open surgery, one of them after an attempt at detachable coil embolization failed. Two patients underwent successful endovascular PCA sacrifice.
The mean GOS and mRS scores in 18 patients with unruptured aneurysms were 4 and 2, respectively, at discharge. Subarachnoid hemorrhage (SAH) from other aneurysms and neurological deficits caused by the PCA lesion or underlying disease contributed to poor outcomes in this group. The mean GOS and mRS scores in 12 patients with ruptured aneurysms were 4 and 4, respectively, at discharge. One patient died of severe vasospasm. Neurological deficits secondary to SAH and, in one patient, treatment of a concomitant arteriovenous malformation contributed to poor outcomes in the patients with ruptured aneurysms. Seven patients with normal visual function preoperatively underwent PCA occlusion. One patient (14%) developed a new visual field deficit.
Conclusions. Optimal treatment of PCA aneurysms is performed via one of several surgical approaches or by endovascular therapy. The approach is determined, in part, by the anatomical location and size of the aneurysm and the presence of underlying disease and neurological deficits.
Phillip Purdy, Charles L. White III, Hunt Batjer, Kirk Brewer, Kurt Hodges, and Duke Samson
✓ Hydroxyethyl methacrylate (HEMA) has been advocated as a polymerizing solution with which to prevent deflation of detachable balloons in interventional neuroradiology. It is pertinent to know if unpolymerized HEMA would have untoward effects if accidentally released into the carotid artery by balloon rupture or deflation. Seven mongrel dogs underwent transfemoral catheterization of the common carotid artery and subsequent injection of HEMA solution in volumes of 1 cc in five dogs, 2 cc in one, and 4 cc in one. Angiography performed at the time of injection revealed evidence of intravascular thrombosis as well as possible spasm. Three surviving animals were sacrificed at 48 hours; the brains were fixed and examined histopathologically. One brain was normal and one was autolyzed and could not be examined. Five of the seven animals had histopathologically documented cerebral infarctions of varying size. No foreign substance was seen within the blood vessels to suggest intravascular polymerization. The animals injected with 2 or 4 cc HEMA solution did not survive 48 hours. Literature review reveals little documentation of the toxicology of intravascular HEMA. With its increasing popularity as a compound for polymerization in detachable balloons introduced into the brain, further investigations are warranted to understand the physical properties of the compound and potential risks of its use.
H. Hunt Batjer, Alan I. Frankfurt, Phillip D. Purdy, Shirley S. Smith, and Duke S. Samson
✓ The operative management of large and giant aneurysms is complicated by their typically atheromatous and thick walls, frequent intramural thrombosis with calcification, and broad-based necks that often incorporate perforating and other vital vessels. Not infrequently, it is necessary to at least focally arrest the intracranial circulation and open or excise these aneurysms to facilitate vascular reconstruction. This maneuver, in patients whose disease processes have destroyed autoregulatory function or who have inadequate sources of anatomical collateral supply, may cause the threshold for permanent ischemic injury to be exceeded. The authors have recently treated 14 such patients while under electroencephalographic monitoring to document electrical burst suppression induced by the administration of etomidate, followed by temporary clipping to permit vascular repair and intraoperative angiography to document patency of parent arteries. Up to 60 minutes of internal carotid artery occlusion, 35 minutes of middle cerebral artery occlusion, 19 minutes of upper basilar artery occlusion, and 4½ minutes of lower basilar artery occlusion have been well tolerated using this protocol. In such situations, etomidate may be effective in protecting the cerebral circulation without the detrimental cardiotoxicity observed with protective doses of barbiturates.
Christopher L. Taylor, Debra Steele, Thomas A. Kopitnik Jr., Duke S. Samson, and Phillip D. Purdy
Object. A case-control analysis of patients with SAH was performed to compare risk factors and outcomes at 6 months posthemorrhage in patients with a very small aneurysm compared with those with a larger aneurysm.
Methods. All patients with SAH who were treated between January 1998 and December 1999 were studied. A very small aneurysm was defined as “equal to or less than 5 mm in diameter.” Clinical data and treatment summaries were maintained in an electronic database. The Glasgow Outcome Scale (GOS) score was determined by an independent registrar.
One hundred twenty-seven patients were treated. A very small aneurysm was the cause of SAH in 42 patients (33%), whereas 85 (67%) had aneurysms larger than 5 mm (mean diameter 11 mm). There were no differences in demographic variables or medical comorbidities between the two groups. Thick SAH (Fisher Grade 3 or 4) was more common in patients with a very small aneurysm than in those with a larger aneurysm (p = 0.028). One hundred eight patients underwent microsurgery (85%), 15 underwent coil embolization (12%), and four (3%) required both procedures. Vasospasm occurred in nine patients (21%) with very small aneurysms compared with 14 (16%) with larger aneurysms (p = 0.62). Shunt-dependent hydrocephalus occurred in nine patients (21%) with very small aneurysms and in 19 (22%) with larger aneurysms (p = 1). The mean GOS score for both groups was 4 (moderately disabled) at 6 months.
Conclusions. Small aneurysms produce thick SAH more often than larger aneurysms. There is no difference in outcome after SAH between patients with a very small aneurysm and those with a larger aneurysm.
Phillip D. Purdy, Takuya Fujimoto, Robert E. Replogle, Brian P. Giles, Hitomi Fujimoto, and Susan L. Miller
The purpose of this paper was to demonstrate the usefulness of various fiberoptic endoscopes for percutaneous intraspinal navigation of the spinal canal, posterior fossa, and ventricular system.
Fresh, unembalmed cadavers were used, in which lumbar punctures were made for access to the sub-arachnoid space (in the case of larger [3.8- and 5-mm-diameter] endoscopes, small laminotomies were performed). Static and video images of pertinent structures were acquired for comparison among devices. Endoscopes were compared for their maneuverability, durability, field of view, and image quality. Seven sizes and types of endoscopes were considered.
Overall, the devices offering a tip-deflecting mechanism were superior in maneuverability. Endoscopes in which a charged couple display chip was used at the tip of the scope for image acquisition offered improved image quality and field of view. Larger scopes, although more durable, were more rigid and may be limited in application. Multiple images from multiple devices are presented.
Percutaneous intraspinal navigation offers a promising neurosurgical approach to the spinal canal, the posterior fossa, and the ventricular system. Concerns regarding safety, management of complications, and the lack of adjunctive tools for intervention through the endoscopes or for use under fluoroscopic guidance represent areas that warrant further investigation and development.