Rate and complications of adult epilepsy surgery in North America: Analysis of multiple databases

Abstract

Epilepsy surgery is under-utilized, but recent studies reach conflicting conclusions regarding whether epilepsy surgery rates are currently declining, increasing, or remaining steady. However, data in these prior studies are biased toward high-volume epilepsy centers, or originate from sources that do not disaggregate various procedure types. All major epilepsy surgery procedures were extracted from the Centers for Medicare and Medicaid Services Part B National Summary Data File and the American College of Surgeons National Surgical Quality Improvement Program. Procedure rates, trends, and complications were analyzed, and patient-level predictors of postoperative adverse events were identified. Between 2000-2013, 6200 cases of epilepsy surgery were identified. Temporal lobectomy was the most common procedure (59% of cases), and most did not utilize electrocorticography (63-64%). Neither temporal nor extratemporal lobe epilepsy surgery rates changed significantly during the study period, suggesting no change in utilization. Adverse events, including major and minor complications, occurred in 15.3% of temporal lobectomies and 55.6% of hemispherectomies. Our findings suggest stagnant rates of both temporal and extratemporal lobe epilepsy surgery across U.S. surgical centers over the past decade. This finding contrasts with prior reports suggesting a recent dramatic decline in temporal lobectomy rates at high-volume epilepsy centers. We also observed higher rates of adverse events when both low- and high-volume centers were examined together, as compared to reports from high-volume centers alone. This is consistent with the presence of a volume-outcome relationship in epilepsy surgery.

Keywords: Complications; Demographics; Epilepsy; Epilepsy surgery; Seizures; Temporal lobectomy.

Fig. 1

Trends of anterior temporal lobectomies as compared to excision of epileptic foci show no significant change overtime from 2000 to 2012. Upper panel: number of cases from the Medicare Part B database for anterior temporal lobectomies (dark blue; CPT codes 61537 and 61538) compared to the number of craniotomies for excision of epileptic foci (light blue; CPT codes 61534 and 61536). Counts include both cases with ECoG and without ECoG. The year 2013 does not include data for CPT code 61534, excision of epileptic foci without ECoG, so this time point was not included in the graph. There were no significant trends in either procedure over time (F = 2.59, p = 0.13 for temporal lobectomies; F = 3.38, p = 0.09 for extratemporal resections). Lower panel: percentage of craniotomies for epileptic foci compared to anterior temporal lobectomies. There is no significant trend over time (F = 4.751, p = 0.052).