Abstracts

Rationale: In medically refractory mesial temporal (MRMT) epilepsy, adequate surgery intended to achieve freedom from seizures with minimal complications is an unsolved matter. Despite the efforts to minimize tissue removal, seizure outcomes resulting from less invasive resections are still suboptimal. By taking advantage of the temporal pole (TP) role in temporal lobe epilepsy and its anatomical importance as a direct pathway for mesial temporal structures, the endoscopic anterior trans-maxillary approach may overcome some limitations of previous selective surgical interventions. In this anatomical and clinical study, we aim to evaluate the safety and feasibility of the endoscopic anterior trans-maxillary approach for mesial temporal lobe epilepsy.

Methods: The study is an ex-vivo and clinical prospective analysis of all consecutive patients who underwent the endoscopic anterior trans-maxillary approach for the treatment of mesial temporal lobe epilepsy. The minimum post-operative follow up period was 6 months. All patients with medical refractory epilepsy whose non-invasive evaluations and intracranial recordings confirmed the presence of a “well-localized” epileptogenic zone located in the mesial temporal structures were included. Seizure freedom outcomes, neuro-psychological results and occurrence of adverse events were analyzed.

Results: In total, 24 human cadaveric hemispheres were operated, and 4 patients underwent the described approach. Confirmed feasibility through anatomical studies allowed the subsequent progression through the clinical series with prospective analysis. Mesial-basal resections of the temporal polar areas and mesial temporal structures (hippocampal formation, parahippocampus gyrus and amygdaloid nucleus) were achieved in all patients. No neurological complications or neuropsychological deficits were observed. Regarding seizure outcome, 3 out of 4 patients achieved Engel I outcome up to the end of the follow-up period.

Conclusions: The anatomical and clinical study demonstrated the early feasibility and potential benefits of a novel and minimally invasive approach for MRMT epilepsy. The study testifies on the possibility of performing anatomically adequate mesial temporal lobe resections through a novel endoscopic transmaxillary approach, avoiding craniotomies or expensive laser ablative procedures.

Funding: Please list any funding that was received in support of this abstract.: N/A.