Chronic subdural hematoma recurrence due to contralateral neovascularization following middle meningeal artery embolization

Chronic subdural hematoma (CSDH) is one of the most commonly encountered neurosurgical diseases. Middle meningeal artery embolization (MMAE) is a technique for the management of CSDH that has elicited promising results. Despite the encouraging results of MMAE, recurrence does occur. One uncommon mechanism for recurrence of CSDH is by means of neovascularization of the contralateral middle meningeal artery (MMA). We describe two cases of CSDH recurrence by means of contralateral middle meningeal artery neovascularization treated with contralateral MMAE.We identified two cases of recurrent subdural hematoma secondary to neovascularization following treatment with contralateral MMAE.Two patients initially treated with MMAE were identified with CSDH recurrence secondary to contralateral MMA neovascularization. There was no traumatic or coagulopathic contribution to CSDH recurrence. In both cases, patients underwent contralateral MMAE. Both patients were neurologically intact with radiographic improvement of CSDH at follow up.Re-accumulation of SDH following MMAE by means of contralateral MMA neovascularization is a rare subtype of subdural hematoma (SDH) recurrence following MMAE. Within the context of re-accumulation of SDH following MMAE, catheter angiography is an important diagnostic investigation to elucidate the etiology of the recurrence. Furthermore, when angiography reveals neovascularization of the contralateral MMA, embolization of the contralateral MMA achieves good clinical and radiographic result.