BACKGROUND: The stereoelectroencephalographic (SEEG) implantation procedures still represent a challenge due to the intrinsic complexity of the method and the number of depth electrodes required. OBJECTIVES: We aim at designing and evaluating the accuracy of a custom stereotactic fixture based on the StarFix™ technology (FHC Inc., Bowdoin, ME) that significantly simplifies and optimizes the implantation of depth electrodes used in presurgical evaluation of patients with drug-resistant epilepsy. METHODS: Fiducial markers that also serve as anchors for the fixture are implanted into the patient's skull prior to surgery. A 3D fixture model is designed within the surgical planning software, with the planned trajectories incorporated in its design, aligned with the patient's anatomy. The stereotactic fixture is built using 3D laser sintering technology based on the computer-generated model. Bilateral rectangular grids of guide holes orthogonal to the midsagittal plane and centered on the midcommissural point are incorporated in the fixture design, allowing a wide selection of orthogonal trajectories. Up to two additional grids can be accommodated for targeting structures where oblique trajectories are required. The frame has no adjustable parts, this feature reducing the risk of inaccurate coordinate settings while simultaneously reducing procedure time significantly. RESULTS: We have used the fixture for the implantation of depth electrodes for presurgical evaluation of 4 patients with drug-resistant focal epilepsy, with nearly 2-fold reduction in the duration of the implantation procedure. We have obtained a high accuracy with a submillimetric mean positioning error of 0.68 mm for the anchor bolts placed at the trajectory entry point and 1.64 mm at target. CONCLUSIONS: The custom stereotactic fixture design greatly simplifies the planning procedure and significantly reduces the time in the operating room, while maintaining a high accuracy.
BACKGROUND: The stereoelectroencephalographic (SEEG) implantation procedures still represent a challenge due to the intrinsic complexity of the method and the number of depth electrodes required. OBJECTIVES: We aim at designing and evaluating the accuracy of a custom stereotactic fixture based on the StarFix™ technology (FHC Inc., Bowdoin, ME) that significantly simplifies and optimizes the implantation of depth electrodes used in presurgical evaluation of patients with drug-resistant epilepsy. METHODS: Fiducial markers that also serve as anchors for the fixture are implanted into the patient's skull prior to surgery. A 3D fixture model is designed within the surgical planning software, with the planned trajectories incorporated in its design, aligned with the patient's anatomy. The stereotactic fixture is built using 3D laser sintering technology based on the computer-generated model. Bilateral rectangular grids of guide holes orthogonal to the midsagittal plane and centered on the midcommissural point are incorporated in the fixture design, allowing a wide selection of orthogonal trajectories. Up to two additional grids can be accommodated for targeting structures where oblique trajectories are required. The frame has no adjustable parts, this feature reducing the risk of inaccurate coordinate settings while simultaneously reducing procedure time significantly. RESULTS: We have used the fixture for the implantation of depth electrodes for presurgical evaluation of 4 patients with drug-resistant focal epilepsy, with nearly 2-fold reduction in the duration of the implantation procedure. We have obtained a high accuracy with a submillimetric mean positioning error of 0.68 mm for the anchor bolts placed at the trajectory entry point and 1.64 mm at target. CONCLUSIONS: The custom stereotactic fixture design greatly simplifies the planning procedure and significantly reduces the time in the operating room, while maintaining a high accuracy.
Authors: Vejay N Vakharia; Rachel Sparks; Aidan G O'Keeffe; Roman Rodionov; Anna Miserocchi; Andrew McEvoy; Sebastien Ourselin; John Duncan Journal: Epilepsia Date: 2017-03-06 Impact factor: 5.864
Authors: Vejay N Vakharia; Roman Rodionov; Andrew W McEvoy; Anna Miserocchi; Rachel Sparks; Aidan G O'Keeffe; Sebastien Ourselin; John S Duncan Journal: J Neurosurg Date: 2018-02-16 Impact factor: 5.115
Authors: Michael C Dewan; Robert Shults; Andrew T Hale; Vishad Sukul; Dario J Englot; Peter Konrad; Hong Yu; Joseph S Neimat; William Rodriguez; Benoit M Dawant; Srivatsan Pallavaram; Robert P Naftel Journal: J Neurosurg Date: 2018-11-01 Impact factor: 5.115
Authors: Barbara Ladisich; Lukas Machegger; Alexander Romagna; Herbert Krainz; Jürgen Steinbacher; Markus Leitinger; Gudrun Kalss; Niklas Thon; Eugen Trinka; Peter A Winkler; Christoph Schwartz Journal: Acta Neurochir (Wien) Date: 2021-02-13 Impact factor: 2.216
Authors: Lars E van der Loo; Olaf E M G Schijns; Govert Hoogland; Albert J Colon; G Louis Wagner; Jim T A Dings; Pieter L Kubben Journal: Acta Neurochir (Wien) Date: 2017-07-05 Impact factor: 2.216
Authors: Alejandro Granados; Roman Rodionov; Vejay Vakharia; Andrew W McEvoy; Anna Miserocchi; Aidan G O'Keeffe; John S Duncan; Rachel Sparks; Sébastien Ourselin Journal: J Neurosci Methods Date: 2020-04-25 Impact factor: 2.390