Abstracts

Rationale: Resection of mesial temporal lobe structures is the definitive treatment for drug-resistant epilepsy arising from mesial temporal sclerosis. Conventional surgical approaches to the mesial temporal lobe result in injury to lateral temporal cortex and white matter tracts, which are associated with cognitive deficits. Recently, we demonstrated the feasibility of accessing the mesial temporal lobe via a lateral transorbital technique using endoscopic visualization in cadaveric specimens. This minimally invasive approach has several theoretical advantages compared to open craniotomy, including the sparing of healthy temporal lobe tissue and the avoidance of risks associated with open craniotomy. We describe our initial clinical experience with the endoscope-assisted lateral transorbital approach to lesions of the temporal lobe.Methods: Two patients with mesial temporal lobe pathology presenting with seizures underwent surgery. A transpalpebral or Stella-Wright eyebrow incision was used to access the intraorbital compartment. A lateral orbital wall “keyhole” craniotomy was then created to allow visualization of the anterior temporal pole. Subsequently, resection of the mesial temporal lobe lesion was performed using endoscopic visualization. We retrospectively reviewed the clinical outcomes of these patients, including their neurological and ophthalmological status and cosmesis.Results: For both patients, the transorbital approach allowed adequate access to resect the targeted lesion. There were no new neurological or ophthalmological deficits after surgery. One patient developed peri-orbital swelling that was consistent with an orbital pseudomeningocele. When presented the options for treating this issue, the patient chose a ventriculoperitoneal shunt for cerebrospinal fluid diversion. At 12-month follow-up, both patients were seizure-free and were at their neurological and ophthalmological baseline. The cosmetic result was described as “excellent” in both cases by the patients and their families.Conclusions: Transorbital endoscopic surgery is a feasible approach for obtaining tissue and resecting lesions in the mesial temporal lobe. This minimally invasive strategy has acceptable outcomes in terms of neurological, ophthalmological, and cosmetic factors. Further investigation is warranted for comparison of this approach to traditional surgical approaches to the mesial temporal lobe and other novel treatment modalities such as laser interstitial thermal therapy.