Five year results of LINAC radiosurgery for arteriovenous malformations: outcome for large AVMS.

PURPOSE: For radiosurgery of large arteriovenous malformations (AVMs), the optimal relationship of dose and volume to obliteration, complications, and hemorrhage is not well defined. Multivariate analysis was performed to assess the relationship of multiple AVM and treatment factors to the outcome of AVMs significantly larger than previously reported in the literature. METHODS AND MATERIALS: 73 patients with intracranial AVMs underwent LINAC radiosurgery. Over 50% of the AVMs were larger than 3 cm in diameter and the median and mean treatment volumes were 8.4 cc and 15.3 cc, respectively (range 0.4-143.4 cc). Minimum AVM treatment doses varied between 1000-2200 cGy (median: 1600 cGy). RESULTS: The obliteration rates for treatment volumes < 4 cc, 4-13.9 cc, and > or = 14 cc were 67%, 58%, and 23%, respectively. AVM obliteration was significantly associated with higher minimum treatment dose and negatively associated with a history of prior embolization with particulate materials. No AVM receiving < 1400 cGy was obliterated. The incidence of post-radiosurgical imaging abnormalities and clinical complications rose with increasing treatment volume. For treatment volumes > 14 cc receiving > or = 1600 cGy, the incidence of post-radiosurgical MRI T2 abnormalities was 72% and the incidence of radiation necrosis requiring resection was 22%. The rate of post-radiosurgical hemorrhage was 2.7% per person-year for AVMs with treatment volumes < 14 cc and 7.5% per person-year for AVMs > or = 14 cc. CONCLUSION: As AVM size increases, the dose-volume range for the optimal balance between successful obliteration and the risk of complications and post-radiosurgical hemorrhage narrows.

Arterial catheter embolization followed by surgery for large chemodectoma.

We report on the first successful preoperative arterial catheter embolization of a large neck chemodectoma followed by its surgical removal. A 21-year-old man presented with a large mass in the right neck diagnosed 5 years previously by biopsy as a chemodectoma. The patient previously had refused therapy. Because of concern over the large size of the mass and increasing difficulty in swallowing, he agreed to undergo therapy. The patient underwent selective occlusion of the occipital and posterior auricular arteries and the thyrocervical trunk using Ivalon sponge emboli injected through a No. 5 Fr Hanafee catheter. A postembolization arteriogram showed 90% occlusion of tumor vascularity and 30% decrease in size of the tumor. This was followed by removal of the tumor surgically. A review of the difficult management of the patient is presented, and implications for future use of the combined procedures are discussed.

Normal perfusion pressure breakthrough occurring during treatment of carotid and vertebral fistulas.

Of the 185 carotid and vertebral fistulas treated by the authors over the past 10 years, five developed neurologic deficits after abrupt closure of their fistulas. The earliest case, treated initially by proximal surgical carotid occlusion, presented 32 years later with cerebral steal symptoms from the large, long-standing carotid cavernous fistula. Upon completion of a surgical trapping procedure, there was immediate massive cerebral edema, brain herniation, and death. In the remaining four patients (three vertebral fistulas and one with carotid cavernous fistula), all treated by transvascular embolization techniques, neurologic deficits occurred coincidentally with the abrupt closure of the fistula and resolved with reestablishment of fistula flow. This indicated that the cerebral vasculature is unable to tolerate the reestablishment of normal cerebral perfusion after abrupt closure of the fistula. All four patients were treated with staged or slow occlusion of their fistulas, which resulted in complete fistula closure without permanent neurologic sequelae. All five patients who developed symptoms consistent with normal perfusion pressure breakthrough had large, long-standing fistulas, ranging in duration from 9 to 32 years. Two of the five patients developed slowly progressive neurologic deficits consistent with cerebral steal prior to treatment. This sign was not observed in the 180 patients who did not develop symptoms during treatment. We conclude that patients with carotid or vertebral fistulas of long duration, particularly those with cerebral steal symptoms, are at risk to develop neurologic deficits related to perfusion breakthrough if their fistulas are abruptly closed. Staged or gradual closure may prevent this potentially devastating complication.

Hemangiomas and vascular malformations of the head and neck: MR characterization.

PURPOSE: To characterize the MR appearance of the common hemangioma of infancy as well as low- and high-flow vascular malformations of the head and neck. PATIENTS AND METHODS: Twenty patients with vascular lesions of the head and neck proved either by pathology, angiography, and/or unequivocal clinical diagnosis were included. Vascular lesions included 15 low-flow lesions (four hemangiomas, 10 venous malformations, one lymphatic malformation), and five high-flow lesions (three arteriovenous malformations (AVMs) and two invasive combined malformations). All patients had MR studies (generally 1.5 T using routine T1- and T2-weighted spin-echo sequences). Nine had postgadolinium, gradient recalled-echo, CT, and/or angiographic studies. FINDINGS: Deep hemangiomas and venous malformations demonstrate intermediate signal in T1-weighted images, heterogeneous high signal on T2-weighted images, and prominent enhancement. Involuting hemangiomas show focal areas of high signal intensity on T1-weighted images due to fatty replacement. Venous malformations may demonstrate venous lakes seen as homogeneous regions of high signal intensity on T2-weighted images and phleboliths seen as low signal foci. The one patient with lymphatic malformation showed a large multicystic submandibular mass with large hemorrhage-fluid levels. Features of high-flow lesions (AVMs) include serpiginous signal voids, absence of a dominant mass, and intraosseous extension with decreased marrow signal on T1-weighted images. Invasive combined vascular malformations showed serpiginous flow voids and infiltrative solid masses. Low-flow lesions (hemangiomas, venous, and lymphatic malformations) demonstrate distinct MR findings allowing their differentiation from high-flow lesions (AVMs). Deep hemangiomas and venous malformations appear as solid masses and may look identical. Venous lakes and phleboliths are features of venous malformations which, when present, may help in diagnosis. Combined vascular malformations share features of both low- and high-flow malformations. CONCLUSION: MR is useful in delineating the extent of disease and differentiating low- and high-flow vascular lesions.

Management of vascular perforations that occur during neurointerventional procedures.

This article describes a number of treatment strategies for the management of perforations that occur during neurointerventional procedures. During the past 5 years, we have performed over 1200 endovascular procedures to treat vascular disorders involving the brain and spinal cord (400 cerebral arteriovenous malformations, 230 tumors, 197 carotid cavernous fistulas, 183 aneurysms, 130 dural fistulas, 80 spinal arteriovenous malformations, 18 vein of Galen aneurysms, and 20 cases of vasospasm). Fifteen patients (1.1%) sustained a vascular perforation as a direct result of these procedures. Among these 15 patients, indications for endovascular treatment were six symptomatic arteriovenous malformations, two spinal cord arteriovenous malformations, two cavernous sinus dural fistulas, one transverse sinus fistula, one case of vasospasm following subarachnoid hemorrhage, one direct carotid cavernous fistula, one vein of Galen malformation, and one ruptured basilar artery aneurysm. The vascular perforations were grouped into three probable mechanisms: mechanical perforation of a normal vessel (six patients), mechanical disruption of a dysplastic vessel or aneurysm (five patients), and fluid overinjection (four patients). Treatment of the perforations included immediate reversal of anticoagulants (12 patients) and direct closure of the perforation site with coils (five patients). In addition, closure of the intravascular compartment adjacent to the perforation was achieved with coils (six patients), liquid adhesives (four patients), balloons (two patients), or particles (two patients). In two patients a detachable balloon was placed transiently across the perforation site for several minutes, deflated, and removed when no further extravasation was noted. Five patients were started on anticonvulsant therapy, two of whom have had a new onset seizure related to the perforation.(ABSTRACT TRUNCATED AT 250 WORDS)

Particulate embolization of the anterior choroidal artery in the treatment of cerebral arteriovenous malformations.

The anterior choroidal artery is commonly recruited to supply arteriovenous malformations in the temporal lobe, basal ganglia, lateral ventricle, and internal capsule. Embolization of this artery is theoretically hazardous owing to its supply to important motor territory, relative lack of collaterals, and small caliber. However, this procedure can be a beneficial adjunct to surgery or radiation in the treatment of arteriovenous malformations. We describe our experience in performing particulate embolization of the anterior choroidal artery in 15 patients (16 procedures). Significant flow reduction was achieved in 14 patients. Two symptomatic and two asymptomatic complications arose, including permanent hemiparesis in one patient.

Transarterial platinum coil embolization of carotid-cavernous fistulas.

Of the 227 embolization procedures performed by our neurointerventional section for symptomatic carotid-cavernous fistulas over the past 10 years, five involved placement of platinum coils in the cavernous sinus from a transarterial route. In four patients, prior transarterial balloon procedures had failed to produce fistula closure. In the fifth patient, with Ehlers-Danlos syndrome, a prior transvenous embolization attempt was unsuccessful. In three patients, complete closure of the carotid-cavernous fistula was achieved with preservation of the parent artery. In one patient, the earliest treated, a portion of a platinum coil projected through the fistula into the parent artery. To eliminate the risk of clot formation and distal embolization, internal carotid occlusion was performed and tolerated without deficits. In the last patient, closure of the anterior drainage was achieved, but complicated by distal migration of the platinum coils with transient aggravation of ocular symptoms. Attempts to occlude the remaining cortical drainage were unsuccessful with platinum coils; therefore, a balloon was used to obliterate the small remaining fistula. Transarterial platinum coil embolization is an alternative treatment for symptomatic carotid-cavernous fistulas that cannot be closed successfully by other embolization techniques. The development of shorter, more thrombogenic, detachable or retrievable coils may make this technique more promising in the future.

Delayed effects in the treatment of carotid-cavernous fistulas.

Carotid-cavernous fistulas may be classified into: (1) internal carotid, (2) external carotid, or (3) a combination of both. They may result from traumatic or spontaneous rupture of the carotid artery into the cavernous sinus. Intravascular embolization has become the treatment of choice for the management of carotid cavernous fistulas. The authors report the delayed effects after the treatment of carotid-cavernous fistulas with experience of 74 cases over the past 6 years. The delayed effects may be summarized as follows: (1) progressive spontaneous occlusion of the fistula after partial balloon embolization, (2) false aneurysms may decrease in size and be spontaneously sealed off, (3) transient and persistent third or sixth cranial nerve palsy may be seen in about 16% of 74 cases, (4) posttraumatic fibrosis with narrowing of the carotid artery may be apparent after total occlusion of the fistula, (5) a prematurely deflated balloon may be dislodged into the carotid artery or its branch, and (6) spontaneous obliteration of common channels from internal carotid artery may occur after total occlusion of external carotid channels in those cases with a combination of internal carotid- and external carotid-cavernous fistulas. Certainly the delayed effect will alter our future planning in the treatment of carotid cavernous fistulas.

Treatment of dural arteriovenous malformations involving the superior sagittal sinus.

We report the diagnosis and treatment of seven dural arteriovenous malformations involving the superior sagittal sinus. The most common presenting symptom was headache, although two patients presented with hemorrhage. Embolization alone effected a complete cure in four patients, while a combination of embolization and surgery was used in the remaining three patients. The first of these had intraoperative exposure and embolization of multiple feeding branches of both middle meningeal arteries, which resulted in a complete cure without deficits. The second patient had multiple embolizations and surgeries with eventual resection of the involved sagittal sinus to effect a complete cure, which was complicated postoperatively by paraparesis. The third patient had preoperative embolization and subsequent surgical resection of the superior sagittal sinus, resulting in a complete cure without deficits. Because of their unique midline location, multiplicity of arterial feeders, and critical venous drainage, dural malformations involving the superior sagittal sinus often require unusual and aggressive forms of therapy.

Transvenous embolization of direct carotid cavernous fistulas.

Of 165 cases of direct carotid cavernous fistula, 14 (8.5%) were treated from a transvenous approach. Twelve of these were treated through the inferior petrosal sinus and one through the superior ophthalmic vein. In one patient, both approaches were used. The embolic agents were as follows: five patients had balloons only, four patients had minicoils alone, three patients had coils and liquid adhesives, one had balloons and coils, and one had balloons and liquid adhesives. Among the patients who were treated from a transvenous approach, three had an occluded carotid artery caused by trauma, nine failed transarterial balloon attempts, and one had a prior trapping procedure. In the remaining patient, who had Ehlers-Danlos syndrome, a transarterial approach was judged to be too dangerous. This patient suffered a fatal pontine hemorrhage after subtotal transvenous occlusion of the carotid cavernous fistula with diversion of flow into cortical veins. Another complication occurred when the inferior petrosal sinus was perforated during catheterization, causing a small subarachnoid hemorrhage. The tear was immediately closed with minicoils, and surgical exposure and embolization resulted in complete cure. Of the remaining 12 patients treated, 11 were completely cured and one showed angiographic and clinical improvement. Transarterial balloon embolization remains the procedure of choice in the treatment of symptomatic carotid cavernous fistulas; however, transvenous embolization is an alternative when the arterial route fails.

Platinum wire: a new transvascular embolic agent.

Standard Gianturco and "mini" coils cannot be used with some of the present microcatheter systems. However, occasions arise in which metallic coils would be an ideal embolic agent in vascular structure accessible only to a tracker (2.2-French) catheter system. We performed nine embolization procedures in eight patients with arteriovenous fistulas using platinum coils as an embolic agent. Fistulas were completely occluded in six of the nine cases. In several cases, platinum wire embolization was augmented with other agents. Complications occurred in two cases, neither resulting in permanent neurologic deficits. Advantages of using platinum coils included availability, radioopacity, thrombogenicity, biocompatibility, and delivery through microcatheters, specifically the tracker catheter system.

New microballoon device for transluminal angioplasty of intracranial arterial vasospasm.

A new microballoon device has been developed to treat intracranial arterial vasospasm by transluminal angioplasty. The balloon is composed of a unique silicone elastomer that will elongate and conform to the blood vessel lumen, thereby decreasing the risk of vessel rupture. The balloon device, which can be either flow-directed or catheter-guided, is permanently affixed to a 2.0-French microcatheter and introduced from a transfemoral arterial approach. Two balloon sizes are currently available. The smaller-sized balloon, used in most cases, measures 0.85 x 3.50 mm uninflated, will accept a volume of 0.10 ml, and will expand to 3.5 x 12.5 mm. The larger balloon, used in six of 14 cases, measures 1.5 x 3.9 mm uninflated, accepts a volume of 0.50 ml, and expands to 7.5 x 13.5 mm. In clinical trials, this device has been successful in dilating both focal and diffuse areas of vasospasm in multiple territories. Thus far, 40 vascular territories have been successfully treated in 14 patients 15-73 years old. In each case, there was angiographic evidence of successful dilatation, and in 10 patients (71%), clinical improvement in the neurologic condition. Transluminal angioplasty techniques may be useful for reversing some of the serious neurologic sequelae associated with acute intracranial arterial vasospasm.

Dural arteriovenous fistulas involving the inferior petrosal sinus: angiographic findings in six patients.

We report the angiographic findings from six patients with intracranial dural arteriovenous fistulas of the inferior petrosal sinus and describe the clinical presentation, vascular anatomy, and embolization techniques used in the treatment of this disorder. Dural arteriovenous fistulas at this site are rare; of 105 patients diagnosed with this abnormality, only six had lesions involving the inferior petrosal sinus. The patients included three men and three women, ranging in age from 41 to 75 years. Patients presented with bruit, proptosis, abducens palsy, or loss of vision, and symptoms were present for up to 1 year prior to diagnosis. These presentations were similar to cavernous sinus arteriovenous fistulas. The arterial supply in all cases was from branches of the external carotid artery and in three cases from the meningohypophyseal trunk of the internal carotid artery. Venous drainage in four patients was via the cavernous sinus to the superior ophthalmic vein. The remaining two patients had drainage primarily to the jugular bulb. In four patients treatment was performed by introducing wire coils into the fistula from the transvenous route. This approach could be used even though the inferior petrosal sinus was thrombosed. One patient, treated early in the series, had only transarterial embolization with both liquid adhesives and particulate embolic agents. One patient had an asymptomatic fistula that was not treated. All patients were cured, as evidenced both angiographically and clinically during the follow-up period. Three patients experienced complications from angiography and treatment: two had transverse sinus thrombosis and one had a transient ischemic attack.

Venography and venous pressure monitoring in dural sinus meningiomas.

This study was undertaken to determine the impact of dural sinus venography and pressure measurements in the evaluation of patients with meningiomas involving the dural sinuses. Of three patients who had MR imaging, arteriography, and dural sinus venography, the latter method better delineated the site and extent of tumor invasion in all three patients. Pressure measurement in one patient reflected the severity of the hemodynamic compromise resulting from narrowing of the transverse sinus. In one patient, dural sinus venography confirmed patency of the superior sagittal sinus that was unsuspected on MR scans and arteriograms. A test occlusion of the area of stenosis in the third patient allowed the surgeon to sacrifice that segment of the sinus without deficit. Dural sinus venography is a useful adjunct to arteriography and MR imaging in the evaluation of invasive meningiomas.

Direct puncture of the proximally occluded internal carotid artery for treatment of carotid cavernous fistulas.

Three patients with symptomatic carotid cavernous fistulas (CCFs) characterized by complete occlusion of the proximal internal carotid artery were treated by percutaneous puncture and embolization. Two patients had CCFs associated with traumatic dissections of the internal carotid artery and were treated initially with trapping procedures. Both patients had persistent symptoms related to the CCF and underwent additional surgical procedures (ophthalmic artery ligation and intraoperative embolization) without improvement. The third patient had traumatic occlusion of the internal carotid artery. After direct percutaneous puncture of the carotid artery above the occlusion, a catheter was advanced into the petrous internal carotid artery. Balloons (one case) or coil emboli (two cases) were placed into the cavernous sinus to produce CCF closure. There were no complications from this procedure. Direct puncture of the carotid artery is an alternative treatment for patients lacking safe access for CCF embolization.

Embolization of branches arising from the cavernous portion of the internal carotid artery.

Seven patients with vascular disease (four with cavernous and two with transverse sinus dural fistulas and one with a facial arteriovenous malformation, all supplied primarily from cavernous branches of the internal carotid artery) underwent subselective catheterization and embolization. Ten branches were catheterized (seven meningohypophyseal trunks and three inferolateral trunks) and eight branches were embolized. The embolic agents were as follows: polyvinyl alcohol particles in five, hypertonic glucose in two, and liquid adhesive in one. All four cavernous sinus dural fistulas were occluded after embolization. In the two transverse sinus fistulas, the goal of embolization was to obliterate the tentorial supply prior to surgery. This goal was achieved in both cases. In the remaining patient, who had a large facial arteriovenous malformation and recurrent epistaxis, the embolization obliterated the cavernous supply to the nasal cavity and the patient remains hemorrhage-free. Despite one complication, which occurred in the first case when a thrombus formed and dislodged, resulting in an embolic stroke, this study shows that subselective catheterization and embolization can obliterate lesions of the branches arising from the cavernous internal carotid artery.

Transvenous embolization of dural fistulas involving the cavernous sinus.

Because of the risks associated with arterial embolization of cavernous dural fistulas, we have sought an alternative method to promote fistula closure. Thirteen patients underwent transvenous embolization as a treatment for symptomatic cavernous dural fistulas. All procedures were performed from a femoral vein access through the inferior petrosal sinus or basilar plexus. In five patients the inferior petrosal sinus was not angiographically demonstrable; however, embolization was still possible through this route in two patients. The embolic agents used were detachable balloons in one patient, coils alone in five, coils and liquid adhesives in four, coils plus silk sutures in one, silk sutures alone in one, and liquid adhesives alone in one. Nine patients had follow-up angiograms, which showed complete obliteration of the fistulas and complete resolution of related symptoms. One patient had complete resolution of clinical symptoms but refused follow-up angiography. Another patient had 50% decrease in fistula flow on the follow-up angiogram and improvement in clinical symptoms. Two patients had complete fistula obliteration after embolization and progressive improvement in symptoms but follow-up angiograms had not been obtained. Follow-ups ranged from 1 to 97 months (mean, 15 months). Two complications were related to this treatment. An embolic stroke followed transient placement of a balloon in the internal carotid in one patient, and a second patient developed transient visual loss when the venous outflow pathways were occluded before fistula closure. The fistula was immediately closed with complete recovery of vision. With recent advances in microcatheter and embolic agent technology, transvenous closure of cavernous dural fistulas is now possible.(ABSTRACT TRUNCATED AT 250 WORDS)

Transvenous embolization of dural fistulas involving the transverse and sigmoid sinuses.

Eleven patients with dural fistulas involving the transverse and sigmoid sinuses were treated by transvenous embolization with coils or liquid adhesives. Seven patients underwent preoperative embolization of the external supply followed by direct surgical exposure of the sinus: liquid adhesives were used in four patients and coils in the remaining three. Four of these patients had complete obliteration of their fistulas and there was 95% reduction in the remaining three. Four patients had transvenous placement of coils from a transfemoral approach. In three, the ipsilateral sigmoid sinus was thrombosed and a contralateral approach across the torcular herophili was used. Coils were used in all four patients; one patient also had liquid adhesives placed within the sinus. Complete cure was achieved in one patient, 95% reduction in another, and 50% and 40%, reductions in the remaining two. Two transient complications occurred, one related to venous occlusion secondary to liquid adhesives and another related to transient occlusion of the vestibular aqueduct. Obliteration of dural fistulas involving the transverse and sigmoid sinuses can be achieved by placement of embolic material within the involved sinus from a transvenous approach; both coils and liquid adhesives can achieve this goal.

Treatment of dural sinus thrombosis by urokinase infusion.

PURPOSE: To gain a preliminary understanding of the role of thrombolytic therapy for the thrombosed dural sinus, we retrospectively reviewed our initial experience. METHODS: Seven patients, ages 25 to 71, who presented with symptomatic dural sinus thrombosis and who failed a trial of medical therapy were treated with direct infusion of urokinase into the thrombosed sinus. Patients received urokinase doses ranging from 20,000 to 150,000 U/h with a mean infusion time of 163 hours (range 88 to 244 hours). RESULTS: Patency of the affected dural sinus was achieved with antegrade flow in all patients. Six patients either improved neurologically over their prethrombolysis state or were healthy after thrombolysis; one of them required angioplasty. The other patient improved after surgical repair of a residual dural arteriovenous fistula. The only complications were an infected femoral access site which resolved after treatment with antibiotics and hematuria which cleared after discontinuation of anticoagulation. CONCLUSIONS: Thrombolysis of the thrombosed dural sinus shows promise as a safe and efficacious treatment. The results of this study should provide the impetus for further research.

Percutaneous transluminal angioplasty of the carotid artery.

Percutaneous transluminal angioplasty (PTA) is being extensively applied to treat arteriosclerotic lesions. However, this application has not been widely accepted for the treatment of carotid artery stenosis. Successful attempts to relieve cerebral ischemia from extracranial carotid arterial stenosis by PTA are reported. Twenty-seven patients with arteriosclerotic stenosis, fibromuscular disease, and Takayasu carotid arterial stenosis were treated by PTA. All anatomic carotid stenotic lesions were corrected without any neurologic complication. Follow-ups ranged from 3 months to 4 years without recurrent symptoms in any patient. These results may suggest that some patients with cerebral ischemia secondary to extracranial carotid artery stenosis may be treated safely and effectively by PTA.