Complications of epilepsy surgery after 654 procedures in Sweden, September 1990-1995: a multicenter study based on the Swedish National Epilepsy Surgery Register.

OBJECTIVE: To present the first national multicenter study on complications after epilepsy surgery procedures to include all epilepsy surgery centers in Sweden: Göteborg, Linköping, Lund, Stockholm, Umeå, and Uppsala.

METHODS: Every epilepsy surgery procedure in Sweden is reported to the Swedish National Epilepsy Surgery Register. The report includes relevant social and medical items and complications. A complication is defined as minor if it resolves within 3 months and major if it affects activities of daily living and lasts longer than 3 months. Follow-up data are recorded for 2 years after the operation. Intrinsic checkpoints and external revision validate the register data.

RESULTS: During the inclusion period (September 1990-December 1995), 654 surgical procedures were performed (age range, 6 mo-67 yr). Of these, 205 were invasive electrode procedures (182 first investigations and 23 reinvestigations), and 449 were therapeutic procedures (375 first operations and 74 reoperations). After invasive electrode procedures, only minor complications were reported (6.3%). For all 449 therapeutic procedures (including reoperations), minor complications were reported in 8.9% and major complications in 3.1 %. Only one major complication was reported in a patient under the age of 35 years.

CONCLUSION: This is the first national multicenter study on complications after epilepsy surgery. It demonstrates that these procedures as performed at six different centers in Sweden are safe, but also that risk is related to age. In patients younger than age 35 years, the risk for a major complication after invasive subdural strip electrode investigation and epilepsy surgery is low.