Indocyanine Green and Contrast-Enhanced Ultrasound Videoangiography: A Synergistic Approach for Real-Time Verification of Distal Revascularization and Aneurysm Occlusion in a Complex Distal Middle Cerebral Artery Aneurysm

Abstract

Distal outflow occlusion and extracranial-intracranial bypass represent a possible option for the surgical management of complex middle cerebral artery (MCA) aneurysm. A limitation of the distal clipping strategy combined to bypass is related to the difficulties in predicting intraoperatively the good blood flow supply to the brain territory distal to the aneurysm and the extent and speed of aneurysmal thrombosis. We present an innovative approach in which contrast-enhanced ultrasound (CEUS) and indocyanine green videoangiography (ICG-VA) have been synergistically used to study the effect of distal clipping on the aneurysm flow and the parenchymal blood flow after the bypass. We used this approach in a patient harboring a fusiform, partially thrombosed distal left MCA aneurysm. The patient was treated by a superficial temporal artery-MCA bypass, followed by MCA clipping immediately distally to the aneurysm. ICG-VA was used to evaluate bypass patency and brain perfusion in the area supplied by the bypass. CEUS was used to confirm the characteristics of the aneurysm and to explore the proximal MCA compartment immediately after dural opening, and to verify in real time the effect on aneurysm flow determined by distal outflow occlusion. Postoperative imaging confirmed aneurysm occlusion and patency of the bypass. The patient did not experience any neurologic sequelae. We present the first report of a synergistic intraoperative utilization of ICG-VA and CEUS in studying parenchymal perfusion and aneurysm flow in complex neurovascular procedures.