Long-term outcomes of epilepsy surgery: A 25-year experience from a tertiary referral center

Despite pharmacological advances in epilepsy treatment, one-third of patients remain pharmacoresistant and may require surgery. Despite extensive literature on epilepsy surgery, studies with follow-ups longer than 5 years are rare. Our goal was to analyze the outcomes of patients undergoing epilepsy surgery at our center, with a minimum follow-up of 15 years.

This was a retrospective study of prospectively collected data. We used the Engel classification to assess seizure freedom, performed univariate descriptive analysis of the variables of interest, and applied appropriate correlation tests for nominal and categorical variables, with statistical significance set at 0.05.

We included 160 patients with a minimum follow-up of 15 years. A total of 105 (70%) patients underwent resective surgeries, the most common being lesionectomy (46.7%), followed by anterior temporal lobectomy with amygdalectomy (21.9%). Among resective surgeries, 73.6% used intraoperative ECOG. Most surgeries were in the temporal lobe (68.8%), and mesial sclerosis was the most frequent etiology (33.8%), followed by long-term epilepsy-associated tumors (LEAT) (25.6%). Seizure freedom at 15 years was achieved by 57.5% of patients, and most of the remaining patients (63.2%) had rare disabling seizures. The majority (65%) discontinued at least one ASM. Temporal surgeries (χ ²(1) = 8.444, p < 0.05), left-sided surgeries (χ ²(1) = 6.436, p = 0.04), mesial sclerosis (χ ²(1) = 50.870, p = 0.024), and the use of intraoperative ECOG (χ ²(1) = 23.235, p < 0.001) were associated with a better prognosis. No differences in outcome were found between the different temporal lobe surgeries (Fisher's exact test value = 0.859, p = 0.659).

Appropriate referral to a refractory epilepsy center permits a multidisciplinary approach that can result in long-term seizure freedom for most patients undergoing surgery, especially for left-temporal lobe surgeries performed with the aid of intraoperative monitoring techniques.