Integration of multimodality imaging and surgical navigation in the management of patients with refractory epilepsy. A pilot study using a new minimally invasive reference and head-fixation system.
OBJECTIVE
To review the experience with a new system (VBH system) for minimally invasive frameless stereotactic guidance, acting as a common platform to provide multimodal image integration and surgical navigation in a consecutive series of 25 patients who underwent surgery for drug-resistant seizures.


METHODS
The usefulness of the VBH system for integrating all images to produce one dataset and for intraoperative instrument guidance and navigation was judged semiquantitatively in a three-tiered scale (+, ++, +++). Seizure outcome was classified according to Engel.


RESULTS
The presurgical evaluation extended over 21.2 months (mean). A total of 141 registrations of images were performed (mean 5.6 per patient, range: 2 to 16). In 19 (76%) of 25 patients structural data fused with functional data were used for the presurgical workup. Six patients proceeded directly to navigated resection. Nineteen patients (76%) underwent invasive recording, of whom 13 underwent resective surgery. In seven patients (28%) the combination of multimodal image fusion and intra-operative stereotactic guidance was judged "essential" (+++) to remove the epileptogenic zone. Integration of all images to form one dataset was "essential" (+++) for decision making in 15 and "helpful" (++) in 4 patients (overall 76% of patients). Intraoperative use of frameless neuronavigation was "essential" (+++) in ten and "helpful" (++) in all remaining patients. Eighty percent of the patients achieved satisfactory seizure outcome after 1 year.


CONCLUSIONS
The VBH system is a safe and effective non-invasive tool for repetitive imaging, multimodal image fusion and frameless stereotactic surgical navigation in candidates for epilepsy surgery.
Ortler
M
M
Clinical Department of Neurosurgery, Innsbruck Medical University, Anichstrasse 35, 6020 Innsbruck, Austria. martin.ortler@i-med.ac.at
Trinka
E
E
Dobesberger
J
J
Bauer
R
R
Unterhofer
C
C
Twerdy
K
K
Walser
G
G
Unterberger
I
I
Donnemiller
E
E
Gotwald
T
T
Widmann
G
G
Bale
R
R
D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D004569:Electroencephalography / Q000295:instrumentation / Q000379:methods; D004827:Epilepsy / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D016267:External Fixators; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000295:instrumentation / Q000379:methods*; D038361:Neuronavigation / Q000295:instrumentation / Q000379:methods*; D010865:Pilot Projects; D011300:Preoperative Care / Q000295:instrumentation / Q000379:methods; D012086:Reoperation; D013238:Stereotaxic Techniques / Q000295:instrumentation; D025321:Surgery, Computer-Assisted / Q000295:instrumentation / Q000379:methods*; D015899:Tomography, Emission-Computed, Single-Photon / Q000295:instrumentation / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000295:instrumentation / Q000379:methods; D016896:Treatment Outcome; D055815:Young Adult