Real-Time Atlas-Based Stereotactic Neuronavigation

Real-Time Atlas-Based Stereotactic Neuronavigation

Neurosurgery 74:128–134, 2014

Surgery for tumors in eloquent brain faces immense challenges when attempting to maximize resection and avoid neurological deficits.

OBJECTIVE: In order to give the surgeon real-time atlas-based anatomic information linked to the patient’s anatomy, we developed a software-based interface between deformable anatomic templates (DATs) and an intraoperative navigation system.

METHODS: Magnetic resonance imaging (MRI), diffusion tensor imaging, and/or functional MRI were performed on 3 patients preoperatively for the purposes of tumor resection by the use of neuronavigation. The DAT was registered to the patients’ navigation coordinate system and utilized coordinates from the navigation system during surgery. This provided the surgeon with a list of proximal anatomic and functional structures and a real-time image of the atlas at that location fused to the patient’s MRI. The clinical feasibility of this approach was evaluated during the resection of 3 eloquent tumors (right postcentral gyrus, left inferior frontal gyrus, and left occipital cuneus gyrus).

RESULTS: Tumor resection was performed successfully in all 3 patients. With the use of the coordinates from the navigation system, anatomic and functional structures and their distances were visualized interactively during tumor resection by using the DAT.

CONCLUSION: This is a proof of concept that an interactive atlas-based navigation can provide detailed anatomic and functional information that supplements MRI, diffusion tensor imaging, and functional MRI. The atlas-based navigation generated distances to important anatomic structures from the navigation probe tip. It can be used to guide direct electrical stimulation and highlight areas to avoid during tumor resection.

Focused opening of the sylvian fissure for microsurgical management of MCA aneurysms

Focused opening of the sylvian fissure for microsurgical management of MCA aneurysms

Acta Neurochir (2014) 156:17–25

A wide sylvian opening, with either a proximal or distal start, has been standard for microsurgical management of middle cerebral artery (MCA) aneurysms. However, extensive sylvian dissection is potentially associated with increased incidence of iatrogenic injury to the brain and neurovascular structures. The aim of the present study was to describe the technique of focused opening of the sylvian fissure for microsurgical management of MCA aneurysms with additional tips on handling difficulties which may be encountered with this technique.

Method A 3D image-based anatomic orientation, clipping field–focused surgical planning, slack brain, and high magnification are the basic requirements for this approach. A 10– 15 mm sylvian opening is placed so that it allows safe access and a good surgical view of the MCA aneurysm clipping field. Under proximal control of the MCA, the aneurysm neck can be dissected and clipped effectively and safely, in this small surgical field.

Results The presented technique has been developed and refined by the senior author during the surgery of 1,097 aneurysms over the last 13 years. It has proved to be safe, and effective for clipping of both ruptured and unruptured MCA aneurysms. Its greatest advantages are a shorter operative time and less brain and vessel manipulation compared to more extensive approaches.

Conclusion The focused sylvian opening is a less-invasive alternative to the classical wide sylvian opening for the microsurgical management of most MCA aneurysms.