gms | German Medical Science

68th Annual Meeting of the German Society of Neurosurgery (DGNC)
7th Joint Meeting with the British Neurosurgical Society (SBNS)

German Society of Neurosurgery (DGNC)

14 - 17 May 2017, Magdeburg

Hemispherotomy – operative technique and seizure outcome 1991 to 2014

Meeting Abstract

  • Thilo Kalbhenn - Evangelisches Krankenhaus Bielefeld, Klinik für Neurochirurgie, Bielefeld, Deutschland
  • Tilman Polster - Epilepsie Zentrum Bethel, Krankenhaus Mara, Bielefeld, Deutschland
  • Heinz W. Pannek - Bielefeld, Deutschland
  • Matthias Simon - Evangelisches Krankenhaus Bielefeld, Klinik für Neurochirurgie Bethel, Haus Gilead I, Bielefeld, Deutschland
  • Christian G. Bien - Epilepsie Zentrum Bethel, Krankenhaus Mara, Bielefeld, Deutschland

Deutsche Gesellschaft für Neurochirurgie. Society of British Neurological Surgeons. 68. Jahrestagung der Deutschen Gesellschaft für Neurochirurgie (DGNC), 7. Joint Meeting mit der Society of British Neurological Surgeons (SBNS). Magdeburg, 14.-17.05.2017. Düsseldorf: German Medical Science GMS Publishing House; 2017. DocDI.04.06

doi: 10.3205/17dgnc203, urn:nbn:de:0183-17dgnc2030

Published: June 9, 2017

© 2017 Kalbhenn et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution 4.0 License. See license information at



Objective: Surgery for treating hemispheral epilepsy was started by Krynauw in 1950. Initially, surgery aimed at removing the lesional hemisphere. More recently almost purely disconnective operative procedures have been adopted by most epilepsy surgeons. We hypothesize that the complete disconnection of the insula as well as the complete resection of the fronto-orbito-dorso-mesial cortical tissue are essential for a good postoperative seizure outcome.

Methods: We retrospectively identified all patients treated at our institution who underwent hemispherotomy from 1991 to 2014 with an epileptological follow-up > 2 years after surgery. In 2013 we changed our operative technique from a periinsular hemispheral disconnection to a keyhole approach with separate disconnection of the insula and additional wide resection of the fronto-orbito-dorso-mesial cortical tissue. The completeness of the disconnection as well as the extent of any tissue resection was documented by MRI. We attempted to correlate the respective operative techniques with the postoperative seizure outcomes (Engel classification)

Results: Between 1991 and December 2014 144 patients (129 children and 15 adults) underwent hemispherotomy. Etiologies did not change significantly over the years. Mean age at hemispherotomy was 7.2 years (median: 4.5 years). 20 patients underwent reoperation for completion of the hemispheral disconnection. Epileptological follow-up data were available in 144 cases with Engel Ia outcomes (freedom of any seizures) in 59.7% of patients at 2 years following surgery. Only 66/120 (55%) patients undergoing surgery before 2013, but 20/24 (83.3%) of cases operated upon after 2013 became seizure-free (p=0.012 Fisher exact test).

Conclusion: Our data coming from one of the largest institutional hemispherotomy series imply that careful and thorough disconnection of the insula and resection of the fronto-orbito-dorso-mesial cortical tissue are crucial surgical steps during hemispherotomy. Our modified technique may significantly improve postoperative seizure outcomes.