462 Burr Hole Hemispherotomy: A Retrospective Series of Seven Cases of Hemispheric Disconnection Performed Via a Single Eighteen-millimeter Burr Hole

INTRODUCTION: Hemispherotomy represents definitive treatment for drug-resistant epilepsy with unilateral hemispheric onset. Traditional approaches involve a large incision and open craniotomy, with associated risks of blood loss, infection, poor wound healing, pain, cosmetic concerns, and long hospital stays. The authors describe a minimally invasive technique for performing a hemispherotomy through a single burr hole overlying the Sylvian fissure. METHODS: A retrospective analysis was performed on the first seven patients to have undergone burr hole hemispherotomy. Data on demographics, hospital stay, complications, completeness of disconnection, and post-operative seizure control were collected. RESULTS: Hemispherotomy was performed through a 15–18 mm burr hole on seven patients–four with epilepsy due to perinatal stroke, one with hemispheric malformation including schizencephaly, and two with a history of traumatic brain injury. Patient ages ranged from 18 months to 21 years at surgery. Complete hemispheric disconnection was achieved in all cases. Estimated blood loss was minimal (mean 25.7 cc, median 20, range 20–50) with no perioperative blood transfusions, intraoperative complications, or deaths. One patient returned to the operating room for closure of a wound dehiscence secondary to a fall. Opioid usage was minimal, with an average total postoperative opioid usage through post-operative day 5 of 468.9 morphine μg/kg equivalents (median 372.6 μg/kg, range 0.0 to 1751.7 μg/kg). One patient experienced a delayed ipsilateral basal ganglia hemorrhage with self-limited symptoms. All patients experienced substantial reduction in seizure burden, with 71% (5/7) achieving Engel Class IA outcome. No patients developed hydrocephalus or shunt malfunction. CONCLUSIONS: The burr hole hemispherotomy approach consistently achieved complete hemispheric disconnection and therefore represents a viable surgical approach. Preliminary results suggest a favorable risk profile.