Onyx Embolization of Tentorial Dural Arteriovenous Fistulas
Onyx Embolization of Tentorial Dural Arteriovenous Fistulas
Institutional review board approval was received for this study. We reviewed a prospectively maintained database of patients with intracranial DAVFs treated at our institution between 2008 and 2011. Nine consecutive patients (mean age 55.8 years) with a tentorial DAVF underwent Onyx embolization and are the focus of this report. Information collected and analyzed included demographics, clinical presentation, radiological features, therapy, perioperative, and late complications.
After diagnostic DSA was performed, general anesthesia was induced. A coaxial (and in some cases with tortuous proximal anatomy, triaxial) technique was used, and the patient received intravenous heparin (activated clotting time goal around 250 seconds). Whenever available, the posterior branch of the MMA was chosen and, under roadmap guidance, superselective catheterization of this vessel was performed using an Echelon 10 microcatheter (Covidien) over a Synchro or a soft-tip Transend microguidewire (Stryker). Choice of the Echelon microcatheter instead of other microcatheters was dictated by the individual operator's greater experience with this microcatheter than other models, having used the Echelon microcatheter for other endovascular procedures. In each case we aimed to reach a microcatheter position as close as possible to the nidus and to "wedge" the microcatheter to assure maximal distal propagation of the embolic material and minimize reflux. Onyx 34 was preferred as the initial concentration to build an embolic "plug." This was true especially in situations in which the microcatheter was not close enough to the actual fistula site to be considered in a wedge position. Onyx 18 was preferred as the initial concentration in cases in which a wedge position was achieved or to follow Onyx 34 after an embolic plug had been formed. After embolization, patients were admitted to a monitored bed in the intensive care unit and discharged the following day or, in patients presenting with acute intracranial hemorrhage, whenever clinically stable.
Each patient underwent follow-up DSA, usually 3–6 months posttreatment, to confirm the durability of occlusion. One patient was recently treated and has not yet reached the recommended 6-month angiographic follow-up point. One patient with incomplete embolization required surgical disconnection. In this patient, exclusion of the fistula after surgery was confirmed by CTA and MRA, but follow-up angiography was not performed. The patient had extremely tortuous vessels and there was a perceived increased risk from DSA. Clinical follow-up information was acquired by means of outpatient visits and/or phone contact. No patient was lost to follow-up.
Methods
Institutional review board approval was received for this study. We reviewed a prospectively maintained database of patients with intracranial DAVFs treated at our institution between 2008 and 2011. Nine consecutive patients (mean age 55.8 years) with a tentorial DAVF underwent Onyx embolization and are the focus of this report. Information collected and analyzed included demographics, clinical presentation, radiological features, therapy, perioperative, and late complications.
After diagnostic DSA was performed, general anesthesia was induced. A coaxial (and in some cases with tortuous proximal anatomy, triaxial) technique was used, and the patient received intravenous heparin (activated clotting time goal around 250 seconds). Whenever available, the posterior branch of the MMA was chosen and, under roadmap guidance, superselective catheterization of this vessel was performed using an Echelon 10 microcatheter (Covidien) over a Synchro or a soft-tip Transend microguidewire (Stryker). Choice of the Echelon microcatheter instead of other microcatheters was dictated by the individual operator's greater experience with this microcatheter than other models, having used the Echelon microcatheter for other endovascular procedures. In each case we aimed to reach a microcatheter position as close as possible to the nidus and to "wedge" the microcatheter to assure maximal distal propagation of the embolic material and minimize reflux. Onyx 34 was preferred as the initial concentration to build an embolic "plug." This was true especially in situations in which the microcatheter was not close enough to the actual fistula site to be considered in a wedge position. Onyx 18 was preferred as the initial concentration in cases in which a wedge position was achieved or to follow Onyx 34 after an embolic plug had been formed. After embolization, patients were admitted to a monitored bed in the intensive care unit and discharged the following day or, in patients presenting with acute intracranial hemorrhage, whenever clinically stable.
Each patient underwent follow-up DSA, usually 3–6 months posttreatment, to confirm the durability of occlusion. One patient was recently treated and has not yet reached the recommended 6-month angiographic follow-up point. One patient with incomplete embolization required surgical disconnection. In this patient, exclusion of the fistula after surgery was confirmed by CTA and MRA, but follow-up angiography was not performed. The patient had extremely tortuous vessels and there was a perceived increased risk from DSA. Clinical follow-up information was acquired by means of outpatient visits and/or phone contact. No patient was lost to follow-up.
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