Computer-assisted surgery
Computer Assisted Surgery ( English computer assisted surgery , CAS), sometimes English computer aided surgery , represents a surgical approach to surgery to plan with computer support and to control their execution. Synonyms are computer-assisted surgery , computer-assisted intervention , image-guided surgery, and surgical navigation . With a CAS, the surgeon constantly receives information about where exactly his instruments are located in the patient's body, even if he cannot see them directly. The systems transmit real-time tracking for this purposeof the instruments in a three-dimensional model of the operating area prepared beforehand from sectional images . CAS is mainly used for minimally invasive procedures, but it is also an important factor in the development of robotic surgery .
Basics
Model of the patient
The most important part of CAS is the development of a precise model of the patient. This can be done using imaging methods such as computed tomography , magnetic resonance imaging , or ultrasound . Today, the recordings are usually made digitally and no longer have to be scanned. It makes sense to combine several modalities. For example, MR images are very high-contrast, but not geometrically accurate; In contrast, CT data are true to their route and angle within the resolution of the scanner used. The images can be presented parallel to each other or optically superimposed ( data fusion ). The fusion can take place semi or fully automatically. The goal is a 3D - dataset , which represents the exact spatial position of normal and diseased tissues and structures of the target region. Image analysis involves editing the patient's 3D model to extract the relevant information. Due to the different levels of contrast of the different tissues, for example, a model can be changed so that only solid structures such as bones are shown, or the course of the arteries and veins through the brain is visible.
Diagnosis, preoperative planning, simulation
For example, a data set can contain data from 180 CT slices, 1 mm thick slices 1 mm apart with 512 × 512 pixels each . The details of both the soft and firm tissue structures can be automatically segmented and then displayed visually separated, e.g. B. be marked in color or released in three dimensions. Landmarks are set manually in order to be able to realign the virtual data record at a later point in time and to compare it with the situation during the operation ( image registration ).
Professional medical viewing software (DICOM viewer, e.g. OsiriX ) can display the segmented and marked data record of the patient as a virtual 3D model. This model can be rotated, cropped and filtered to give the surgeon views from every possible angle and depth. This allows the surgeon to better assess the case and make a more accurate diagnosis. Then the surgical intervention is planned and virtually simulated before the actual operation takes place. If a surgical robot is available, it is now programmed to carry out the planned actions during the current surgical procedure.
Intervention
During the procedure, the surgeon sees in real time how his instrument is aligned and where it is located in the three-dimensional patient model. Usually he has a monitor for this; however, there are now also innovative systems with data glasses ( augmented reality ). The instruments are tracked optically, for example, by following the markings attached to them in infrared light from several spatial directions, or via electromagnetic transmitters. Mechanical tracking systems (axes and hinges with sensors) are too imprecise and no longer in use.
In this way, the surgeon should better assess the surgical difficulties and better define his approach. The procedure becomes more precise and the surgeon's hand movements are less redundant . One also expects a generally better ergonomics in the operating room; the risk of errors should be reduced and the operation time shortened.
Robot assisted surgery
Surgical robots are high-precision industrial robots , i.e. mechanical arms that are controlled by the computer. Robotic support always consists of the interaction of the surgeon and the robot; So far there are no robots that operate independently. Depending on the degree of interaction, a distinction is made between tele-surgical, shared-control , and supervised-controlled robotic surgery. Supervised interventions are carried out after extensive preparation by the robot, which implements preprogrammed commands; the surgeon observes it and can interrupt it at any time. With shared control , the surgeon guides the instrument while the robot actively stabilizes it (e.g. prevents tremors or keeps it away from predefined positions). In telesurgery, the surgeon controls the robotic arms himself. His console can stand next to the patient or at any distance; even on another continent.
application areas
The most important area of application of the CAS is neurosurgery on the brain. Remote manipulators have been used for this since the 1980s. In maxillofacial surgery , bone segment navigation is a modern concept for operations on the temporomandibular joint or for facial reconstruction . The navigated implant is a prosthetic and surgical assistance process in the oral-maxillofacial surgery and dentistry to dental implants precisely in the jaw bone to use. ENT surgeons are also familiar with areas with restricted access and the need for high-precision action, such as in middle ear surgery. Computer-assisted orthopedic surgery (CAOS) is widely used in orthopedics , especially in hip and knee replacement. It is also useful for planning and guiding operations in the osteosynthesis of displaced bone fractures. In general and gynecological surgery, laparoscopy is benefiting from this progress, for example for hysterectomy (removal of the uterus). In 1994 in Montreal, biliary tract operations were performed with computer-controlled micromanipulators. In cardiac surgery , control systems can perform mitral valve replacement or ventricular stimulation via small thoracotomies . In urology, surgical robots help with pyeloplasty (renal pelvic surgery ), nephrectomy (surgical removal of a kidney), and procedures on the prostate .
Also radiosurgery (a form of radiation therapy) is often performed today with the involvement of robotic systems, such as the CyberKnife . A linear accelerator is mounted on an industrial robot and is aligned with the tumor using the skeletal structures as a frame of reference (stereotactic radiosurgery system). X-rays are used during the procedure to accurately position the device prior to delivery of the beams.
Systems
1989–2007 more than 200 CAS systems were developed by various universities and research institutes, practically still experimental devices. Current commercial systems approved for clinical use are mainly StealthStation (Medtronic, USA), EnLite (a transportable system from Stryker Corporation ) and NavSuite (Stryker Corporation), MATRIX POLAR (Scopis medical / XION, Germany), VectorVision (Brainlab, Germany ), DigiPointeur (Dr. Lombard / Ste COLLIN, France). All except DigiPointeur and StealthStation use an optical IR tracking system. DigiPointeur is an electromagnetic tracking system, and StealthStation uses an electromagnetic (PoleStar) or optical IR tracking system. The StealthStation provides both optical and electromagnetic tracking systems.
The first surgical robot was called Aesop (Computer Motion, USA); Aesop 1000 received regulatory approval from the Food and Drug Administration (FDA) in the United States in 1993 . There were several improvements and variants, such as Zeus or Hermes .
The Da Vinci surgical system was developed by Intuitive Surgical , a branch of the Stanford Research Institute (USA). Da Vinci is a tele-surgical system, mostly used in laparoscopic abdominal surgery. It received FDA approval in 1997, and in 2000 it was the first remote manipulator to receive FDA approval to perform stand-alone surgery. After heated arguments, the two manufacturers finally merged, still under the Intuitive Surgical brand.
OrthoDoc and Robodoc are robots developed by Integrated Surgical Systems for assistance in orthopedic surgery. The same company produced Neuronate , which can be used in conjunction with OrthoDoc / Robodoc in neurosurgery.
CyberKnife (Accuray Incorporated) is a robot with an integrated linear accelerator that has been used in radiosurgery since 2001.
New technological processes and devices can lead to new and unforeseen risks for the patient and / or the surgical team. As long as they are used experimentally rather than in regular operation, the responsible ethics committees must approve their use. The procedures, which are often very expensive at the beginning, cannot be offered everywhere, so ethically the question of equal access to medical care arises.
See also
literature
- Peter Michael Schlag, Sebastian Eulenstein, Thomas Lange (Eds.): Computer-assisted surgery. Elsevier, Urban & Fischer, 2012. ISBN 3437593269 .
Individual evidence
- ^ R. Marmulla, H. Niederdellmann: Computer-assisted bone segment navigation. In: Journal of Cranio-Maxillo-Facial Surgery . 26, 1998, pp. 347-359. (English)
- ^ NT Berlinger: Robotic Surgery - Squeezing into Tight Places. In: New England Journal of Medicine . 354, 2006, pp. 2099-2101. (English)
- ↑ Operation with 3-D and navigation aid. ( Memento of May 13, 2010 in the Internet Archive ) on the WDR website, accessed on May 2, 2011.
- ↑ navigated knee replacement on the page of the knee consultation of the orthopedics clinic in Dortmund, accessed on May 2, 2011.
- ↑ Ernst Kern : Seeing - Thinking - Acting of a surgeon in the 20th century. ecomed, Landsberg am Lech 2000. ISBN 3-609-20149-5 , p. 39.
- ↑ M. Muntener, D. Ursu, A. Patriciu, D. Petrisor, D. Stoianovici: Robotic prostate surgery. In: Expert Rev Med Devices. 3 (5), 2006, pp. 575-584. (English)
- ^ Bertrand Guillonneau: What Robotics in Urology? A current point of view. In: European Urology . 43, 2003, pp. 103-105.
- ↑ eNlite Navigation System ( Memento of the original from February 12, 2015 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. by Stryker Corporation / USA, accessed September 18, 2011.
- ↑ Cyberknife in the OR (PDF; 365 kB) accessed on May 3, 2011.
