Preparation for Surgery for Dural Arteriovenous Fistulas in Children

Indications for the Procedure

• Symptoms indicating surgery: Surgery is indicated in patients with a hemorrhagic presentation, cardiac failure, and/or presence of cortical venous drainage with venous hypertension.

Preoperative Orders

• Standard preparation for surgery: Order blood type and crossmatch (to have in the operating room), full blood count, and coagulation studies. Also, adequate intravenous hydration must be achieved prior to treatment.
• Antiepileptic drugs: If seizures are present, consider the use of antiepileptic drugs.
• Blood products: Fresh frozen plasma, platelets, and concentrated prothrombin complex need to be reserved and readily available in case of major bleeding.

Anesthetic Considerations

• Blood loss: Anticipate early and inform the anesthesiologist if major bleeding is anticipated or occurs; this includes during the skin incision, given the potential recruitment of ECA feeders.
• Fluid overload: Fluid overload can also be a concern in patients with cardiac failure.
• Renal injury: The total contrast dose for interventional procedures is limited in children.

Devices to be Implanted

• Aneurysm clips: In order to disconnect the fistula, permanent aneurysm clips may be used.
• Cranioplasty meshes: In cases of large bony defects after skeletonization, absorbable and nonabsorbable meshes may be used, along with bone substitutes.
• Dural substitutes: In cases of a large dural defect after resection, dural substitutes may be used.
• Embolic agents: Materials used in embolization procedures for DAVF include coils and liquid embolic agents, such as Onyx.

Ancillary/Specialized Equipment

• Operative microscope: An operative microscope should be ready when performing the craniotomy and before the dura is opened — many fistulas involve transosseous arterial and venous channels.
• Intraoperative angiogram: An intraoperative DSA may be used to confirm complete obliteration after surgery. Prep and drape the groin before the surgery is started.
• Intraoperative Doppler: Intraoperative Doppler can also assist with detection of residual flow in the fistula. However, a baseline assessment is important to understand the relative change after surgical ligation. Normal Doppler signal would also exist in nearby pial vessels.