# Temporary Tumor Perfusion Changes From Subcutaneous Lidocaine With 1% Epinephrine During Particle Embolization for Meningiomas

## TL;DR

Injecting lidocaine with epinephrine under the skin helps improve embolization of meningiomas by reducing unwanted blood flow.

## Contribution

A novel technique using subcutaneous lidocaine with epinephrine to enhance particle embolization of meningiomas is introduced.

## Key findings

- Subcutaneous lidocaine with epinephrine suppressed transosseous blood flow, improving tumor embolization.
- Post-embolization angiography showed reduced tumor enhancement with no injection-related side effects.
- The method effectively restored antegrade flow via the middle meningeal artery during embolization.

## Abstract

Preoperative embolization of meningiomas aims to minimize intraoperative bleeding and improve surgical outcomes. Effective embolization requires an embolic material to reach the tumor’s feeding arteries. In particle embolization, particles travel via arterial blood flow to occlude feeding vessels within the tumor. To enhance embolization, we temporarily reduced transosseous blood flow from the cutaneous artery by inducing contraction of the superficial temporal artery (STA) and occipital artery (OA) through subcutaneous injection of lidocaine with epinephrine. A patient with a meningioma involving the superior sagittal sinus underwent preoperative embolization. A microcatheter was inserted into the middle meningeal artery (MMA), and angiography revealed tumor staining with late-phase backflow from perfusion pressure in other feeders. Using roadmap images from external carotid angiography, clustered cutaneous artery areas were identified. Subcutaneous injection of 1% lidocaine with epinephrine was administered, resulting in expanded tumor staining and restored antegrade blood flow via the MMA. Embolization using Embosphere particles followed. Postoperative angiography showed reduced tumor enhancement, with no side effects from the injection. Subcutaneous lidocaine with epinephrine effectively suppresses the dominant transosseous blood supply, enhancing tumor embolization. This technique appears promising for improving preoperative outcomes.