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Clinical-Project Neurosurgery Presented By : Amin Younis Omer Krieger Eyal Hendel Faculty of Biomedical-Engineering Technion

Anatomical Background:

Anatomical Background The nervous system Central nervous system – CNS. Peripheral nervous system – PNS. The CNS Consists of three main parts: Spinal cord, Brainstem and cerebellum, Cerebrum. Has a fundamental role in the control of behavior.

Anatomical Background: The Meninx:

Anatomical Background: The Meninx A system of membranes that envelop the CNS. Consists of three layers: The Dura matter The Arachnoid mater The Pia matter Cerebrospinal fluid (CSF)

Anatomical Background: Neurons:

Anatomical Background: Neurons The major class of cells in the nervous system. Have an excitable membrane that can generate and propagate active potential from one cell to another. Consist of cell body Dendrites and Axon.

Anatomical Background: The Brain:

Anatomical Background: The Brain Two hemispheres separated by the central fissure and connected by the corpus callosum. Responsible of all cognitive functions and regulation of automatic processes. The function of each part of the brain is known only in general manner.

Neurological Surgery: Definition:

Neurological Surgery: Definition A discipline of medicine and that specialty of surgery which provides the operative and nonoperative management of disorders of the central, peripheral, and autonomic nervous systems, including their supporting structures and vascular supply. U.S. Accreditation Council of Graduate Medical Education

Neurological Surgery: Conditions treated by neurosurgeons:

Neurological Surgery: Conditions treated by neurosurgeons Spinal stenosis Hydrocephalus Head or spinal cord trauma Brain tumors Cerebral aneurysms Hemorrhagic stroke movement disorders

Neurological Surgery: Clinical challenge:

Neurological Surgery: Clinical challenge An exquisitely complex three-dimensional space. Problematic accessibility to many targets. Microscopic environment with macroscopic influence. Lack of knowledge about the functional structures. Needs an optimal intelligent, practiced, and prudent surgeon

Stereotactics: Definition:

Stereotactics: Definition Stereotactic surgery is a minimaly invasive form of surgical intervention which makes use of a three-dimensional coordinates system to locate small targets inside the brain and to perform on them some action. "Stereotactic" in Greek means movement in space.

Stereotactics: Historical Background:

Stereotactics: Historical Background Was first developed by two British scientists in 1908, Sir Victor Horsley and Robert H. Clarke. Anatomical points inside the brain as the pineal gland were used as reference. The method presently uses IGS.

Image-Guided Surgery (IGS) How it works ?:

Image-Guided Surgery (IGS) How it works ? Stereotactic surgery works on the basis of three main components: A stereotactic atlas of the targeted anatomical structures A stereotactic device or apparatus A stereotactic localization and placement procedure

Stereotactics: Base Ring Placement:

Stereotactics: Base Ring Placement The patient is mildly sedated and four points on the scalp are infiltrated with local anesthetic (Lidocaine). The ring is then fastened to the patient's skull with four pins, inserted through the anesthetized regions. The exact pin sites are determined based on the location of the lesion. The localizing ring is then attached to the base ring.

Stereotactics: Imaging:

Stereotactics: Imaging The patient is taken to the neuroradiology department where a CT or MRI is performed. The image obtained in conjunction with the localizing ring allows the neurosurgeon to compute the exact three dimensional position of the region of interest by the intersection of two projections.

Stereotactics: Calculating The Point:

Stereotactics: Calculating The Point A line in 3-D space can be described by the following vector equation:   a vector parallel to the line and t a free parameter allowing a position on the line to be specified. If line is written as:   The vectorial equation of the line is then:

Stereotactics: Arc Mounting:

Stereotactics: Arc Mounting The patient is brought to the operating room. The frame is fixed to the operating table with the head only slightly elevated above the chest to avoid air embolism. A small patch of hair is shaved over the appropriate region. The stereotactic arc is brought into the target position.

Stereotactics: Procedure Summary:

Stereotactics: Procedure Summary Fixing the base-ring Localiser frame being fitted obtaining the Co-ordinates Verifying the Target Arc-localiser fitted Progress

Frameless Stereotactics:

Frameless Stereotactics Relies on fiducial markers which are taped to the scalp before the brain is imaged. In the operating room the orientation of these markers is used to register the computer containing the brain images. Once registration is completed, the computer can show the relationship of our surgical instruments to the imaged brain.

Frameless Stereotactics: Advantages over a frame-based system :

Frameless Stereotactics: Advantages over a frame-based system Easier to use on children due to the elimination of the rigid frame Allows smaller, more precise incisions Facilitates detection and removal of residual tumor Verifies complete tumor removal Shortens time in surgery Reduces complications

Stereotactics: Applications:

Stereotactics: Applications Surgical treatment of Parkinson's disease by Deep Brain Stimulation (DBS). Tumor resection Biopsy, precise tissue sampling with minimal brain damage Vascular malformations treatment Aneurysms, and abscesses Functional neurosurgery, such as epilepsy, chronic pain

Stereotactics: Problems:

Stereotactics: Problems Blind surgical procedure with many complex geometric variables. Not only are such instruments out of the surgeon's site, but they may be tilted, rotated, and extended in many different directions Infections caused by the pin-holes in the skull Lack of correspondence in the coordinate system of the stereotactic frame or localizer used by the surgeon seldom to the patient's "brain coordinate system." Time consuming Brain shift relevant to initial reference points

Brain Shift: Definition:

Brain Shift: Definition Tissue deformation and shift, occurring during neurosurgery due to: Loss of cerebrospinal fluid and cortical swelling Tumor decompression Collapse of neural tissue around the operative site Example of Brain Shift

Brain Shift: Consequences:

Brain Shift: Consequences Due to the inhomogeneous nature of the brain, the displacements will vary from point to point based on local elasticity and intra-cranial pressure. Therefore, the magnitude of the brain shift will be dependent on the size and location of the tumor. A large brain shift, if not corrected, will result in inaccuracies in surgical procedures and has the potential to cause damage to normal tissue.

Imaging in the OR:

Imaging in the OR Resection control Maintain navigational accuracy despite brain shift Complication avoidance Enables the surgeon to make smaller incisions 1.5T Image MR Image taken in OR

Imaging in the OR: Resection Control:

Imaging in the OR: Resection Control Pre Intra Intra Post

Imaging in the OR: Maintaining accuracy despite Brain Shift:

Imaging in the OR: Maintaining accuracy despite Brain Shift Detection and correction of Brain Shift during surgery is essential to the preservation of neuronavigation accuracy. As navigation is based on images acquired intraoperatively, Brain Shift is accounted for inherently. Navigation account of Brain Shift

Navigation on Up-to-date Images:

Navigation on Up-to-date Images The key function of surgical navigation is to determine the position of the surgical instruments in space so as to set them in relationship to the image date sets and the patient, thus producing a direct spatial correlation between patient images, patient anatomy, and surgical instruments.

Navigation on Up-to-date Images:

Navigation on Up-to-date Images Measuring the location in surgical optical navigation is based on the principle of geometrical triangulation. Infrared light-emitting diodes (LED) are detected by means of a stereo CCD-camera system, in order to determine the positions of the LEDs in space. Integrated positioning system (Polaris) with camera ( A ) tracks the position of the patient reference frame ( B ), the ultrasound probe ( C ), biopsy forceps ( D ), sterile pointer ( E ), or CUSA ( F ).

Imaging + Navigation: US based:

Imaging + Navigation: US based Integration of 3D Ultrasound and neuronavigation Enables the surgeon to plan and navigate using preoperative MR or CT images and also in a similar manner navigate directly by intraoperative 3D ultrasound. The system consists of a high-end ultrasound scanner, a modest-cost computer, and an optical positioning/digitizer system. SonoWand® by MISON

Imaging + Navigation: MR based:

Imaging + Navigation: MR based Intraoperative MR Imaging system designed for installation in a conventional OR Allows for real-time visualization during all stages of brain surgery: pre-, intra- and post-operative image guidance. PoleStar N20® by Odin

Future Innovations: Robot-assisted neurosurgery :

Future Innovations: Robot-assisted neurosurgery The increasing need for greater magnification and smaller tools has made the human hand unfeasible to perform the neurosurgical tasks. Improvements in computer technology, engineering, minimum invasive surgery, along with the new neuroimaging techniques, created the concept of digital robotic neurosurgery. Consists of the following components: robotic arm, feedback sensors, controllers (instructs the robot), wireless localization system and a data processing center.

Future Innovations: Surgical robots Classification:

Future Innovations: Surgical robots Classification Supervisory-Controlled Systems: The procedure is planned beforehand and the surgeon specifies the motions which the robot goes through.

Future Innovations: Surgical robots Classification:

Future Innovations: Surgical robots Classification Telesurgical Systems: The surgeon directly performs the operation with a haptic interface. Using a force feedback joystick control, the surgeon carries out motions that the surgical manipulator replicates.

Future Innovations: Surgical robots Classification:

Future Innovations: Surgical robots Classification Shared-Control System: The robot undergoes steady-hand manipulations of the surgical instrument while the surgeon controls the whole procedure.

Future Innovations: Robot-Assisted Microsurgery System (NASA, Washington DC) :

Future Innovations: Robot-Assisted Microsurgery System (NASA, Washington DC) Based on master-slave control with 6 degrees of freedom, allowing 3-D manipulation, and not just limited to stereotactic procedures. Along with adjustable tremor filters and motion scaling, it was able to improve the precision of the surgeon.

Future Innovations: NeuRobot (Shinshu University School of Medicine, Matsumoto, Japan) :

Future Innovations: NeuRobot (Shinshu University School of Medicine, Matsumoto, Japan) Performs telecontrolled surgery through an endoscope. The 10-mm endoscope contains twin tissue forceps, a camera, a light source, and a laser. The investigators removed a tumor from a patient, and found the system to be more accurate and less invasive then traditional methods McBeth et al. Robotics in neurosurgery . Am J Surg. Oct;188: 68-75, 2004 .

Future Innovations: Robot-assisted neurosurgery: Required Improvements :

Future Innovations: Robot-assisted neurosurgery: Required Improvements More accurate models of brain biophysical properties Dexterity enhancements, as the current movements are much slower than those done by the human hand. Better adaptation to the deformability of soft brain tissue Tactile feedback

Future Innovations: Robot-assisted neurosurgery: Tomorrowland:

Future Innovations: Robot-assisted neurosurgery: Tomorrowland Ambidextrous abilities, more degrees of freedom, kinesthetic feedback, and a more user-friendly interface Greater integration of artificial intelligence and nanotechnology

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