Embolization of AV malformation

General: Patients may be symptomatic (due to the lesion or subarachnoid hemorrhage) or asymptomatic. You should know the location and type of the cerebrovascular malformation, any neurological deficits and if the patient has had a subarachnoid hemorrhage and SAH grade if applicable.
Preop: Start an IV. Premedicate with up to 2 mg of midazolam.
Monitors: Routine monitors. Foley catheter inserted after induction of anesthesia. Monitoring devices must be positioned so that they do not hinder radiologic visualization of the cerebral vasculature, or the aortic arch area.
Anesthesia: Goal is to have the patient stay still while the microcatheters are in intracranial blood vessels. Movement may cause for the catheters to perforate an intracranial blood vessel. If the patient has a high likelyhood of being treated, or comes intubated from the ICU, general anesthesia will be administered. The goals of general anesthesia are to induce and maintain anesthesia without causing further morbidity (avoid hypotension and hypercapnia if increased ICP is suspected), prevent patient movement (poor image quality and risk of catheter related complications), and rapid emergence from anesthesia to allow neurologic examination soon after procedure. Induction with propofol. In case of increased ICP, have patient hyperventilate during preoxygenation. Fentanyl 3 µg /kg in divided doses throughout induction, prior to intubation. Verify adequate neuromuscular blockade prior to intubation to avoid coughing/straining. Tape eyes, insert esophageal temperature probe. Maintain anesthesia with oxygen, low dose inhalation agent or propofol infusion. Maintain euvolemia (Lactated Ringer’s) and neuromuscular relaxation (vecuronium or rocuronium). Movement during the procedure can be extremely dangerous (intracranial bleed). Avoid significant hypotension before embolization (phenylephrine infusion). Heparin (porcine) is usually administered before embolization, and redosed hourly. Have protamine (50 mg) available in a syringe to be used emergently in case of an intracranial bleed. During and after embolization, maintain blood pressure at or below awake pre anesthesia values. Use of inhalation agents or propofol is usually stopped at the end of procedure. Reverse residual neuromuscular blockade. Consider prophylactic use of labetalol to attenuate emergence hypertension. During the procedure, if requested, administer nitroglycerin ointment (typically one inch of nitropaste applied on the chest) to prevent catheter induced vasospasm. If the patient has an EVD that is draining, be vigilant about the radiologist changing the table height.
Potential complications: Intracranial bleeding. Movement during procedure.
Recovery: Wake patient up immediately after the procedure to allow neurologic examination. Use a hemodynamic monitor and supplemental oxygen during patient transport to ICU.