Scalp Necrosis After Preoperative Embolization for Convexity Meningioma: Anatomical Considerations and Microsurgical Salvage

Preoperative embolization for hypervascular meningiomas may compromise scalp perfusion despite its rich anastomotic network. A 63-year-old man developed occipital scalp necrosis after Onyx embolization of the bilateral occipital and middle meningeal arteries before convexity meningioma resection, followed by osteomyelitis requiring multiple debridements. Definitive coverage was achieved with a free anterolateral thigh flap anastomosed to the preserved superficial temporal vessels. At 5 months follow-up, healing was stable. The authors' hypothesis is that extensive external carotid embolization compromised dominant inflow and rendered the scalp dependent on a midline subgaleal anastomotic rete. In this setting, a midline incision crossing this rete may have transected the choke vessels recruited to sustain perfusion, even when the lateral cutaneous pedicles were preserved. Awareness of this potential mechanism and preservation of recipient vessels are essential when planning combined endovascular-surgical strategies.