Use of a microsnare to aid direct thrombolytic therapy of dural sinus thrombosis.

Subject and Methods The patient was a 21-year-old, right-handed woman who presented with headache and neck and shoulder pain of 3 weeks’ duration. Several days later, she complained of nausea, vomiting, and horizontal diplopia. She had no significant medical history; medications were oral contraceptives. Initial neurologic examination was notable for severe papilledema. Lumbar puncture revealed an opening pressure of 430 mm H20 (normal range, 50-180 mm H,O). A presumptive diagnosis of pseudotumor cerebri was made, and the patient was treated with acetazolamide. She was then transferred to our institution because of persistent headaches and progressive visual failure. MR imaging revealed extensive thrombus in the superior sagittal, transverse, and sigmoid sinuses (Fig. 1A). The patient was treated with IV heparin and underwent a right optic nerve sheath fenestration because visual acuity in the right eye was initially slightly worse than that in the left eye. Despite anticoagulation therapy, the patient became lethargic and complained of worsening headache. A second lumbar puncture revealed an opening pressure of greater than 600 mm H,O. In addition, visual fields were constricted, and corrected visual acuity in the left eye rapidly deteriorated from 20/25 to 20/200. Angiography performed at this time confirmed extensive thrombus in the dural sinuses. A 7French guiding catheter (Medtronic Micro Interventional Systems. Sunnyvale. CA) was then placed in the right internal jugular vein. A Tracker I 8 microcatheter (Target Therapeutics, Fremont, CA) was then advanced into the sigmoid. transverse. and superior sagittal sinuses. After initial infusion of approximately 200,000 IU of urokinase over approximately 45 mm. little change in the appearance of the thrombus had occurred. Subsequently, mechanical disruption of the clot was performed by repeatedly dragging a snare (Amplatz Goose Neck microsnare; Microvena, White Bear Lake, MN) through the clot, thus increasing the surface area of thrombus exposed to the thrombolytic agent (Fig. IB). A total of 1 million IU of urokinase was infused by a pulse-spray technique. Angiography performed at the conclusion of the procedure revealed marked improvement in flow in the dural sinuses (Fig. IC). After the procedure, the catheters were removed, and anticoagulation therapy was begun, initially with IV heparin and subsequently with oral warfarin sodium (Coumadin; Du Pont Pharma, Wilmington. DE). Over the next 12 hr. the patient’s headache and lethargy resolved. Visual acuity in the left eye returned to 20/50. and the left eye visual field improved over the next week. MR venography performed approximately 2 weeks later confirmed dural sinus patency (Fig. I D). Discussion Dural sinus thrombosis is likely an underdiagnosed condition. Clinical manifestations are variable, ranging from headache to seizures to hemorrhagic infarction to coma. Predisposing conditions include trauma, infection, dehydration, malignancy, and hypercoagulable states, including pregnancy and oral contraceptive use [3]. Prompt restoration of venous outflow from the brain is required to prevent potential progression to massive cerebral edema and hemorrhagic infarction. First-line therapies include hydration, removal of potentially causative agents, and systemic anticoagulation with hepann. Thrombolytic agents, including urokinase, streptokinase, and tissue plasminogen activator, have been used in the treatment of this condition. Reported durations of infusion (range, 2-43 hr) and dosages of thrombolytics have been variable [4-6]. Local delivery of thrombolytics has been advocated to speed clot resolution [5], particularly in the setting of neurologic deterioration despite adequate systemic anticoagulation therapy. Thrombolysis has also been advocated when brain parenchyma changes (swelling and signal abnormality) are seen on MR imaging; such changes have been shown to be reversible [5]. Mechanical thrombolysis has been described in laboratory studies [7] and in the treatment of