The field of interventional neuroradiology has experienced remarkable technological developments in microcatheters and embolic materials during the past two decades. The realm of meningioma therapy has benefited handsomely from the combination of these technical improvements and the knowledge of experienced practitioners in this field. Transarterial embolization has become a standard procedure in the preoperative management of meningiomas. The authors describe the indications, pretreatment evaluation, techniques, and outcomes when preoperative angiography and embolization are performed in the treatment of these tumors.
Christopher F. Dowd, Van V. Halbach, and Randall T. Higashida
Leslie D. Cahan, Randall T. Higashida, Van V. Halbach, and Grant B. Hieshima
✓ In recent years, it has become evident that the most common form of arteriovenous malformation to involve the spinal cord in adults is a low-flow fistula with its nidus located on the dura in relation to the dorsal nerve root. This lesion, termed “radiculomeningeal fistula” (RMF), is drained by the intradural coronal venous system and most likely causes neurological deficits due to raised venous pressure within the spinal cord. The therapy that was formerly recommended was multilevel laminectomy with microsurgical stripping of the intradural vessels. However, that procedure focused on the draining veins rather than the nidus, and it has been replaced by direct treatment of the nidus or by disconnecting the nidus from the coronal venous system. This paper reports variants of RMF's that show a wider spectrum of the clinical and radiological findings than has been previously reported. Three patients presenting with extradural venous drainage, intraspinal hemorrhage, and/or sudden non-hemorrhagic neurological decline are reported. A more complete understanding of RMF facilitates the radiological and clinical evaluation of these patients and enables the surgeon to modify the therapy in a significant way.
Grant B. Hieshima, Randall T. Higashida, Joseph Wapenski, Van V. Halbach, Leslie Cahan, and John R. Bentson
✓ Interventional neurovascular techniques have advanced to a level where treatment of intracranial aneurysms by intravascular detachable balloon embolization therapy is now possible. A patient is presented who had a spontaneous subarachnoid hemorrhage from a large aneurysm of the distal basilar artery. The aneurysm arose at the bifurcation of the posterior cerebral arteries and measured 15 × 9 × 9 mm. With the patient fully awake, a detachable silicone balloon was passed into the basilar artery by a transfemoral arterial approach. Stenosis (> 60%) of the mid-section of the basilar artery, secondary to arterial vasospasm from the recent hemorrhage, was present. The stenosis was treated by transluminal angioplasty, after which the balloon was passed into the aneurysm and detached. A follow-up angiogram 3 months later demonstrated complete occlusion of the aneurysm and a widely patent basilar artery at the angioplasty site.
Results of combined endovascular and neurosurgical treatment in 16 patients
Stanley L. Barnwell, Van V. Halbach, Randall T. Higashida, Grant Hieshima, and Charles B. Wilson
✓ Of the 88 patients evaluated for symptomatic dural arteriovenous (AV) fistula over the past 8 years, 16 had large or complicated lesions that could not be treated with standard transvascular approaches or in which such treatment had been unsuccessful. Eleven fistulas were located in the transverse sinus, two in the cavernous sinus, two in the straight sinus, and one in the falx-tentorial region near the vein of Galen. The patients were treated with a combination of endovascular and neurosurgical techniques. Fourteen patients underwent preoperative transarterial embolization; this procedure closed the fistula in one patient. In the remaining 15 patients, surgery was performed to provide access to the fistula for embolization from either the venous or the arterial side, or for excision of the fistula. Transvenous embolization completely obliterated the fistula in seven of nine patients; the fistulas were embolized incompletely through the feeding arteries in two patients; and complete surgical resection of the lesion was accomplished in four patients. Complications related to venous occlusion occurred in two patients and one patient suffered communicating hydrocephalus that was effectively treated by shunting. There were no deaths. The results suggest that combined endovascular and neurosurgical techniques are a safe and effective means for the treatment of selected complex dural AV fistulas.
Randall T. Higashida, Van V. Halbach, Leslie D. Cahan, Grant B. Hieshima, and Yoshifumi Konishi
✓ Treatment of complex and surgically difficult intracranial aneurysms of the posterior circulation is now being performed with intravascular detachable balloon embolization techniques. The procedure is carried out under local anesthesia from a transfemoral arterial approach, which allows continuous neurological monitoring. Under fluoroscopic guidance, the balloon is propelled by blood flow through the intracranial circulation and, in most cases, can be guided directly into the aneurysm, thus preserving the parent vessel. If an aneurysm neck is not present, test occlusion of the parent vessel is performed and, if tolerated, the balloon is detached.
Twenty-six aneurysms in 25 patients have been treated by this technique. The aneurysms have involved the distal vertebral artery (five cases), the mid-basilar artery (six cases), the distal basilar artery (11 cases), and the posterior cerebral artery (four cases). The aneurysms varied in size and included three small (< 12 mm), 15 large (12 to 25 mm), and eight giant (> 25 mm). Fifteen patients (60%) presented with hemorrhage and 10 patients (40%) with mass effect. In 17 cases (65%) direct balloon embolization of the aneurysm was achieved with preservation of the parent artery. In nine cases (35%), because of aneurysm location and size, occlusion of the parent vessel was performed. Complications from therapy included three cases of transient cerebral ischemia which resolved, three cases of stroke, and five deaths due to immediate or delayed aneurysm rupture. The follow-up period has ranged from 2 months to 43 months (mean 22.5 months).
In cases where posterior circulation aneurysms have been difficult to treat by conventional neurosurgical techniques, intravascular detachable balloon embolization may offer an alternative therapeutic option.
Grant B. Hieshima, Randall T. Higashida, Joseph Wapenski, Van V. Halbach, and John R. Bentson
✓ A patient who presented with multiple episodes of subarachnoid hemorrhage was diagnosed as having a large mid-basilar artery aneurysm that had no definable surgical neck. Balloon embolization was performed utilizing two detachable silicone balloons to occlude the mid-basilar artery and the aneurysm. The procedure was carried out with the patient fully awake and alert. One day after the procedure, the patient developed pontine and cerebellar ischemia which completely resolved after 5 days on heparin therapy. A follow-up angiogram performed immediately after the procedure and at 3 months demonstrated complete occlusion of the mid-basilar artery and the aneurysm. The patient was intact neurologically upon discharge 5 days after the embolization procedure and has since resumed his normal activities. Balloon embolization therapy may offer some advantages over surgical methods for the treatment of such therapeutically challenging aneurysms.
Perry P. Ng, Randall T. Higashida, Sean Cullen, Reza Malek, Van V. Halbach, and Christopher F. Dowd
Interventional neuroradiology is a less invasive modality than open neurosurgery for the treatment of a wide range of neurovascular disorders. Refinements in technique and improvements in the design of microcatheters, guide wires, and embolic materials have yielded superior clinical outcomes and provided an impetus to treat more of these lesions endovascularly rather than surgically. Endovascular therapy is the standard of care for direct and indirect carotid artery cavernous sinus fistulas and may also be curative for dural arteriovenous fistulas (AVFs) in other locations.
The authors provide review of the clinical features, pathophysiology, and management of intracranial AVFs focusing on contemporary endovascular treatment options.
Van V. Halbach, Randall T. Higashida, Christopher F. Dowd, Kenneth W. Fraser, Tony P. Smith, George P. Teitelbaum, Charles B. Wilson, and Grant B. Hieshima
✓ Sixteen patients with dissecting aneurysms or pseudoaneurysms of the vertebral artery, 12 involving the intradural vertebral artery and four occurring in the extradural segment, were treated by endovascular occlusion of the dissection site. Patients with vertebral fistulas were excluded from this study. The dissection was caused by trauma in three patients (two iatrogenic) and in the remaining 13 no obvious etiology was disclosed. Nine patients presented with subarachnoid hemorrhage (SAH), two of whom had severe cardiac disturbances secondary to the bleed. The nontraumatic dissections occurred in seven women and six men, with a mean age on discovery of 48 years. Fifteen patients were treated with endovascular occlusion of the parent artery at or just proximal to the dissection site. One patient had occlusion of a traumatic pseudoaneurysm with preservation of the parent artery. Four patients required transluminal angioplasty because of severe vasospasm produced by the presenting hemorrhage, and all benefited from this procedure with improved arterial flow documented by transcranial Doppler ultrasonography and arteriography.
In 15 patients angiography disclosed complete cure of the dissection. One patient with a long dissection of extracranial origin extending intracranially had proximal occlusion of the dissection site. Follow-up angiography demonstrated healing of the vertebral artery dissection but persistent filling of the artery above the balloons, which underscores the need for embolic occlusion near the dissection site. No hemorrhages recurred. One patient had a second SAH at the time of therapy which was immediately controlled with balloons and coils. This patient and one other had minor neurological worsening resulting from the procedure (mild Wallenberg syndrome in one and minor ataxia in the second).
Symptomatic vertebral artery dissections involving the intradural and extradural segments can be effectively managed by endovascular techniques. Balloon test occlusion and transluminal angioplasty can be useful adjuncts in the management of this disease.
Jared Narvid, Matthew R. Amans, Daniel L. Cooke, Steven W. Hetts, William P. Dillon, Randall T. Higashida, Christopher F. Dowd, and Van V. Halbach
Retroclival hematomas are rare, appearing mostly as posttraumatic phenomena in children. Spontaneous retroclival hematoma (SRH) in the absence of trauma also has few descriptions in the literature. None of the reported clinical cases features the combination of an SRH and intraventricular hemorrhage (IVH). Nevertheless, despite extensive cases of idiopathic or angiographically negative subarachnoid hemorrhage (SAH) of the posterior fossa, only a single case report of a patient with a unique spontaneous retroclival hematoma has been identified. In this study, the authors reviewed the presentation, management, and clinical outcome of this rare entity.
The authors performed a retrospective analysis of all patients with diagnosed SRH at their institution over a 3-year period. Collected data included clinical history, laboratory results, treatment, and review of all imaging studies performed.
Four patients had SRH. All were appropriately evaluated for coagulopathic and/or traumatic etiologies of hemorrhage, though no etiology could be found. Moreover, all of the patients demonstrated SRH that both clearly crossed the basioccipital synchondrosis and was contained within a nondependent configuration along the retroclival dura mater.
Spontaneous retroclival hematoma, often associated with IVH, is a rare subtype of intracranial hemorrhage frequently recognized only when MRI demonstrates compartmentalization of the posterior fossa hemorrhage. When angiography fails to reveal an underlying lesion, SRH patients, like patients with traditional angiographically negative SAH, enjoy a remarkably good prognosis.