A classification system for verifying the long-term efficacy of resective surgery for drug-resistant seizures.

•To verify long-term efficacy of epilepsy surgery, we created a classification system.•The system’s basic components were patterns of postoperative seizure emergence.•We analyzed postoperative seizures in 646 patients with 8+ years of follow-up.•The results confirmed the validity and usefulness of our classification system.•Our system clarifies effectiveness of surgery more precisely than the Engel scale.