Abstracts

Rationale: Surgical resection remains one of the principle interventions for medically intractable epilepsy. Unfortunately, medically refractory pediatric epilepsy is often more complex than adult population due to the prevalence of extratemporal seizure origins. Furthermore, the outcomes of extratemporal epilepsy surgery are often not as good as temporal lobectomy. Little is known regarding long-term repeat epilepsy surgery in failed first time pediatric epilepsy surgery. We intend to analyze our own experience with long-term outcomes after first time and repeat resective surgery in our pediatric cohort.Methods: 105 pediatric patients (59 male, 46 female) who underwent epilepsy surgery (mean age: 9 years, median age: 8.5 years, range: 4 months-18 years) were retrospectively reviewed. Surgeries included focal cortical resections or lobectomies (n=86) and hemispherectomies (n=19). Palliative procedures such as VNS device implantation and corpus callostomies were excluded. Twenty-two patients were repeat surgical cases due to breakthrough seizures despite a prior resection. Results of repeat patients were reported based on their last surgery. Outcomes were analyzed using SPSS via the Kaplan-Meier method, censoring positive outcomes Engel I-IIA (“excellent outcomes”) per most recent follow-up (post-surgery follow-up mean: 41 months, median: 39 months, range: 7-101 months, SD: 22 months). Events for the negative outcomes were assigned on the date of first break-through seizure. Long-term outcomes were compared using Wilcoxon Rank Statistics.Results: Overall, the data showed that 66% (69 out of 105) patients achieved excellent surgical outcomes. Only 2 excellent outcome patients were lost to follow-up less than a year post-operation. Of the focal resections, 56 (65%) had excellent outcomes, and of the 19 functional hemispherectomies, 13 (68%) had excellent outcomes. The difference between these two subsets of patients was not statistically significant (p=0.42). For first time surgical patients, 66% (55 out of 83) had excellent outcomes and had a mean survival time of 67 months. For repeat surgical patients, 64% (14 out of 22) had excellent outcomes and a mean survival time of 59 months. The outcomes and mean survival times between these two subsets did not differ significantly (p=0.76). The Kaplan-Meier survival curve illustrates the similar outcomes among first time (""single"") and repeat (""multiple"") resection patients.Conclusions: The overall outcomes observed from our pediatric cohort are comparable to reported outcomes from adult populations. The data suggests no difference in seizure outcomes among patients undergoing hemispherectomies versus focal resections. Interestingly, patients who underwent repeat operation had comparable outcomes to patients undergoing resection for the first time. This may be explained by the advances in multimodality neuroimaging. This study corroborates surgical resection as a means of treatment for medically intractable epilepsy in children and also suggests that previously failed epilepsy surgery should not preclude reevaluation for repeat resective surgery.