Charles P. Steiner

Use of a frameless, armless stereotactic wand for brain tumor localization with two-dimensional and three-dimensional neuroimaging

Preliminary experience with a frameless, armless stereotactic localization system in brain tumor surgery is presented. The localizing wand emits ultrasonic pulses that are detected by a table-mounted array of microphones--with triangulation of the emitter positions. The wand tip and trajectory are determined by proprietary computer software. Real-time display of this information is presented in multiple, two-dimensional or three-dimensional displays. Forty-eight patients underwent 52 craniotomies for brain tumors. The wand was used to assist in placing a minimal craniotomy in 48 cases, to determine the tumor/brain interface in 27 cases, to localize subcortical tumors in 14 cases, and to correlate the physiological mapping with the surface anatomy in 5 cases. In 12 instances, the wand was used in conjunction with frame stereotaxy and found to be comparable or superior. Triplanar (coronal, sagittal, transverse) two-dimensional images provided sufficient information for the detection of tumor boundaries but proved difficult to use to access a subcortical lesion; two-dimensional or three-dimensional images along the localization axis were more helpful. Frameless stereotaxy with this sonic wand system proved to be a useful adjunct to open-tumor biopsy or resection.

Electrical stimulation of sphenopalatine ganglion for acute treatment of cluster headaches.

(Headache 2010;50:1164‐1174)

Acute Treatment of Intractable Migraine With Sphenopalatine Ganglion Electrical Stimulation

Background.— We report preliminary results of a novel acute treatment for intractable migraine. The sphenopalatine ganglion (SPG) has sensorimotor and autonomic components and is involved in migraine pathophysiology.

Intraoperative, real-time 3-D digitizer for neurosurgical treatment and planning

Summary form only given. An easy-to-use interface has been developed that allows real-time image localization and 3-D volume data set reformatting for use with computed-tomography (CT) and magnetic-resonance-imaging (MRI) images. As the basis for an intraoperative armless and frameless means of head stereotaxis, the surgeon uses a 3-D digitizer and an ultrasonic neurowand intraoperatively to register fiducials located on a patients head with image voxels stored in a workstation. Once this registration step is performed, the tip of the wand can be located in both the image and patient coordinate systems. In near real-time, coronal, sagittal, and axial sections (triplanar display) of the patients anatomy located by the wand are displayed on a graphics workstation. The neurowand has been used to chart and record the positions of scalp and intradural electroencephalography electrodes in 3-D MRI volume data sets. Three-dimensional rendering of these data reveals the precise location of the electrodes with respect to the gyral and sulcal anatomy of the brain.<<ETX>>

Registration of EEG electrodes with three-dimensional neuroimaging using a frameless, armless stereotactic wand.

A technique of image and electrode registration has been developed that allows electroencephalogram electrode location to be merged with 2-D or 3-D MRI or CT. An armless, frameless stereotactic localization system that may be used in or out of the operating room is used to generate spatial data for surface and accessible intracranial electrodes. Acquisition of electrode position data may be obtained before or after neuroimaging and the locations of additional electrodes added at any time. The methodology of this system and representative cases with MRI imaging are presented.

Robotically assisted gynaecological surgery

Industry has used robots successfully for fine, delicate, repetitive tasks for decades. Recently, robots have been introduced into clinical medicine and specifically into the surgical suite. Voice algorithms have been developed that allow voice activation of some types of equipment in the operating room, such as the laparoscope or the light source. Advances in computer software have allowed a computer controller to translate a surgeons movements from the handles located in a console to the robotic arms that hold the surgical instruments. This console is placed away from the surgical table. Clinical experience is limited and there are few published clinical trials. The initial trials have focused on laparoscopic microsuturing such as that performed during coronary bypass surgery or tubal anastomosis. Preliminary results have demonstrated that laparoscopic coronary bypass surgery with the internal mammary artery can be achieved. In gynaecological surgery, laparoscopic tubal reanastomosis can be performed using the same technique that has been used traditionally at laparotomy. Future clinical trials will assess whether other gynaecological procedures can be performed with robotic assistance.

A low-cost PCI-bus-based ultrasound system for use in image-guided neurosurgery

A low-cost PCI-bus-based ultrasound sub-system has been developed and integrated into the image-guided neurosurgery system currently in use at the Cleveland Clinic. Two software applications have been developed that integrate real-time ultrasound images with preoperative MR and CT data sets. By tracking the position of the ultrasound probe during surgery, it is possible to display a real time ultrasound image and the corresponding (preoperative) oblique CT or MR slice. This provides immediate positional feedback to the neurosurgeon during the surgical procedure.

3-D microfabricated electrodes for targeted deep brain stimulation

This work presents a novel 4-sided, 16-channel deep brain stimulation electrode with a custom flexible high-density lead for connectivity with pulse generation electronics. The 3-dimensional electrode enables steering the current field circumferentially. The electrode is fabricated in pieces by micromachining and microfabrication techniques; the pieces are then assembled mechanically to form the electrode, after which the lead is connected. The electrode is modeled by finite element analysis and tested in vitro to validate the design concept, i.e., targeted stimulation. Simulation and experimental results for a targeted stimulation show close agreement. With a symmetric bipolar stimulation configuration, within a 3 mm radius, the electric potential in front of the activated side is at least 3.6 times larger than that on the corresponding two adjacent, not-activated sides, and 9 times larger than the corresponding opposite, not-activated side.

Stereotactic magnetic resonance angiography.

Visualization of the surgical trajectory with respect to the cerebral vasculature may enhance the safety of some stereotactic neurosurgical procedures. Traditional stereotactic angiography is tedious and, being an invasive procedure, poses some risk to the patient. A technique of projecting a stereotactically defined surgical trajectory onto magnetic resonance angiograms is presented.

Adaptation of personal projection television to a head-mounted display for intra-operative viewing of neuroimaging

We describe an adaptation of a personal projection television for intra-operative viewing of conventional neuroimaging and frameless stereotaxy displays. In addition to image display, the device provides surgical magnification and eye protection from body fluids. Image data is first processed by a scan converter to provide a National Standards Television Committee (NTSC) television signal. The adjustable optics of the system display are permanently secured to avoid displacement during surgery. A virtual image of the data is projected to an apparent size of four feet in the inferior visual field of the surgeons dominant eye. Magnification is provided by the surgical telescopes mounted in the visor. Resolution of the device is consistent with that obtained in a slice of computed tomography or magnetic resonance imaging data. Optimal display of multiplanar data awaits improvement in density of the light emitting diode device used for image generation.