Long-term outcomes of pediatric epilepsy surgery: Individual participant data and study level meta-analyses

Abstract

Objective: Long-term seizure outcomes of pediatric epilepsy surgery are understudied. A systematic review and independent patient data meta-analysis was performed to study seizure outcomes ≥ 10 years following pediatric resective epilepsy surgery.

Methods: Electronic literature searches of PubMed, Web of Science, and CINAHL were conducted for relevant articles from inception to April 2020. The following search terms were used in various combinations: "pediatric", "child", "adolescent", "epilepsy", "resective", "surgery", "long-term", "longitudinal", "10 year". Two reviewers (W.B.H., T.B.C.) performed title, abstract, and full-text screening. All relevant perioperative factors reported that may be associated with long-term seizure outcomes were recorded at a study or individual participant level. The primary outcome was long-term (≥ 10 year) seizure freedom measured by the Engel Classification scale, and available data on functional outcomes were also reviewed.

Results: Twenty-five articles met criteria for inclusion in the study, which were analyzed for proportions of 10-year seizure freedom ranging from 57.6% at the study level to 64.8% at the individual patient level. At the study level, the proportion of patients remaining seizure free at least 10 years postoperatively (61.2%; 95% CI 52.5-69.3) was significantly less than at 1 year (74.2%; 95% CI 69.3-78.6; p = 0.008) but not at 2 years (67.9%; 95% CI 58.6-76.0) or 5 years (63.7%; 95% CI 55.4-71.2). No differences in long-term seizure freedom were detected by etiology or surgery type. At the individual patient level, univariate logistic regression analyses of all variables putatively associated with seizure freedom demonstrated that lobectomy (OR 0.280, 95% CI 0.117-0.651, p = 0.003) was associated with decreased long-term seizure freedom (41.9%) compared to lesionectomy (75.7%) and hemispherectomy (69.4%), which achieved similar results.

Conclusion: Resective surgery is a durable and potentially curative treatment option for select pediatric patients with refractory epilepsy. On a group level, two-thirds of children have long-term seizure freedom ≥ 10 years after resective epilepsy surgery. Given the greatest rate of change occurs in the first 2 years, this may serve as the best short-term follow-up period to predict long-term outcome. Although lobectomy appears to be a strong predictor for lower likelihood of long-term seizure freedom, long-term prognostication on an individual patient level is still not possible. Uniform data reporting and prospective, multicenter studies collecting high quality, stratified (e.g., by etiology, surgery type) data over an extended postoperative interval are recommended to further examine the durability of resective surgery as a treatment for pediatric epilepsy.

Keywords: Long-term; Meta-analysis; Outcomes; Pediatric epilepsy surgery; Resection.