Dr Ryan T Kellogg’s Management Tips for Cerebral Arteriovenous Malformations in Children

• Consider preoperative embolization: Preoperative embolization can reduce the vascularity of the AVM and make surgery safer.
• Review angiogram postembolization: Studying the angiogram after embolization can prepare the surgeon to identify key anatomy, such as the arterial supply and venous drainage.
• Conceptualizing this in the 3D surgical space is important.
• ICG can supplement the preoperative angiogram: ICG provides real time representation of the flow and shunting.
• AVM exposure important: Providing adequate exposure to control the entirety of the lesion is important; it allows dissection to separate the AVM from the brain, rather than traversing the AVM.
• The embolization material can provide additional reference landmarks during the dissection.
• Clips or cautery can achieve hemostasis of the AVM feeders.
• Interval ICG can supplement postoperative angiography to demonstrate complete resection.

Preoperative evaluation and embolization: A child presented with an AVM in the superficial left temporal lobe. DSA was performed to evaluate the lesion’s arterial supply and venous drainage. The angiogram revealed an AVM with a small nidus and superficial venous drainage. Two feeding arteries were embolized with Onyx 34 (liquid embolic agent). Post-embolization DSA revealed a small amount of residual flow.

Exposure and initial ICG imaging: A craniotomy was performed, and the dura was opened over the left temporal lobe. A surgical microscope was used to visualize the surgical field and facilitate careful AVM resection. An overlay of a 3D reconstruction of this AVM demonstrates the feeding arteries, nidus, venous varix (dilated component of draining vein), and the superficial draining vein. Initial ICG imaging was performed to further evaluate the lesion’s flow patterns. The dilated draining vein is clearly demonstrated.

Arachnoid dissection and superficial arterial supply: The arachnoid was carefully opened to gain access to the subarachnoid space, and the superficial arterial supply was identified and coagulated.

Dissection along posterior nidus: Careful dissection proceeded along a corridor flanking the posterior nidus. This was facilitated by familiarity with the 3D configuration of the AVM, including the nidus and its associated vasculature.

Dissection of venous varix: The venous varix was carefully dissected from the surrounding tissue.

Disconnection of nidus: Following additional dissection around the nidus, another feeding artery was identified and clipped. AVM clips are visible in this view. After clipping, the feeding artery was cut to disconnect the nidus from the cerebral vasculature.

Dissection along anterior nidus: A dissection plane was identified along the anterior nidus, which was dissected from surrounding tissue.

Clipping of last feeder and removal of nidus: The last remaining feeding artery was clipped and disconnected from the nidus. The draining vein was taken, and the nidus was removed.

Inspection of operative cavity: After removal of the nidus, the resection bed was inspected for residual nidus and active bleeding.

Confirmation of complete resection: Prior to closure, ICG imaging was performed, and an angiogram (DSA) was obtained postoperatively. Both imaging modalities demonstrated that the AVM was completely resected.