As human beings become more comfortable sharing their space with robots, we can expect that robotic technologies will infiltrate even more aspects of our lives. For the past decade or so, robotic systems for surgery have been tested, approved by the U.S. Food and Drug Administration (FDA), and used successfully to perform operations that previously required highly invasive surgical procedures. Robotic systems have been used in tens of thousands of procedures including general, urologic, gynecologic, and cardiac procedures such as mitral valve repair.
These robotic surgical systems provide benefits to both the surgeons and their patients. Traditional procedures such as heart surgery require large (up to 8” or 10”) incisions and opening of the rib cage; in robot-assisted heart surgery, there are three or four small incisions. Patients experience a shorter hospital stay, less pain, less risk of infection, less blood loss, less scarring, and faster recovery. Surgeons benefit from better visualization, precision, dexterity, and control than what’s possible using traditional surgical approaches.
Degrees of Help
Current robotic systems for surgery fall into three main categories: supervisory, surgeon-guided, and tactile or sharedcontrol. The main difference between each system is how involved the surgeon must be when performing a surgical procedure. In some cases, robots perform surgical techniques without the direct intervention of a surgeon. In others, doctors perform surgery with the assistance of a robot, but the doctor is doing most of the work. As part of the pre-operative planning stage, surgeons use computer tomography (CT) or other types of images of the patient’s body to determine the best surgical approach.
Shared-control robotic systems aid surgeons during surgery, but the doctor does most of the work. The surgeon provides power for the instruments while the robotic arm constrains the instrument position within a registered volume. In orthopedic surgery, for example, surgical tools can damage soft tissue, so the robot constrains the area the surgeon can operate within by providing force feedback. As the surgeon approaches the soft tissue, the robot pushes back against the surgeon’s hand, offering more resistance. If the surgeon continues cutting toward the soft tissue, the robot locks.
From a regulatory standpoint, the FDA pays close attention to the potential for error and whether robotic equipment meets performance standards. The agency evaluates the possibility of technical failure of the computer and whether it translates into any risk for patients. The FDA requires manufacturers to train surgeons before they can use robotic surgical systems on patients. Currently, it takes an average of 12 to 18 procedures (depending upon the type of procedure) before surgeons feel comfortable and are able to perform the procedures as quickly as with standard techniques.
da Vinci™ Surgical System
In July 2000, the FDA cleared the da Vinci Surgical System from Intuitive Surgical of Sunnyvale, CA as an endoscopic instrument control system for use in laparoscopic (abdominal) surgical procedures such as removal of the gallbladder. In 2001, the FDA cleared da Vinci for use in general non-cardiac thoracoscopic (inside the chest) surgical procedures.
The da Vinci system is a robotic surgical platform that consists of a surgeon’s console, a patient cart with four interactive robotic arms, a vision system, and patented EndoWrist® instruments. The system is designed to enable complex procedures to be performed through 1-2 cm incisions or operating “ports,” into which the surgeon inserts three or four stainless steel rods. The robotic arms hold the rods in place. One of the rods has two endoscopic cameras inside it to provide a stereoscopic image, and the other rods contain the miniaturized instruments that dissect and suture the tissue. Unlike conventional surgery, the doctor does not touch these surgical instruments directly.
The surgeon sits at a console to view a magnified, high-resolution, 3D image of the surgical site. To operate, the surgeon uses master controls that work like forceps. As the surgeon manipulates the controls, da Vinci responds to the surgeon’s input in real time, scaling, filtering, and translating his or her hand, wrist, and finger movements into movements of the instruments at the patient-side cart. Once the surgery is complete, the surgeon removes the rods from the patient’s body and closes the incisions.
The system cannot be programmed, and it cannot make decisions on its own. It requires that every surgical maneuver be performed with direct input from the surgeon. The surgeon views an actual image of the surgical field while operating in real time.
Dr. Eugene A. Grossi is a Professor of Cardiothoracic Surgery at New York University (NYU) School of Medicine and the Director of Cardiac Surgery Research. He is also the Director of Cardiothoracic Surgery at the Manhattan VA Medical Center, and an attending surgeon at NYU Medical Center, at Bellevue Hospital Center and at the New York Veterans Administration Medical Center. Dr. Grossi uses the da Vinci system for certain procedures, and is internationally recognized as a pioneer for his work in robotic assistance in minimally invasive mitral valve surgery.
According to Dr. Grossi, “As with any operative procedure, there is a good amount of advance planning. But in addition to the typical planning, with a robotic system, you also have to plan for port placement and access for both the scope and the ports. You have to be concerned about the relationship of the device to the patient so you don’t have external conflicts.”
Although Dr. Grossi no longer uses the system for specific cardiac procedures, he stressed that there are some procedures for which it is very enabling. “Working deep inside the pelvis is extremely difficult to do with hand instruments,” he explained. “For a radical prostatectomy, it’s very potentiating.”
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RIO™ Robotic Arm Interactive Orthopedic System
The RIO™ Robotic Arm Interactive Orthopedic System from MAKO Surgical Corp. in Fort Lauderdale, FL, was the first FDA-cleared robotic arm system for orthopedic surgery. It provides patient-specific, 3D modeling for pre-surgical planning. The system is used in the company’s MAKOplasty® Partial Knee Re surfacing for patients with osteoarthritis in only one part of the knee. By selectively targeting the portion of the knee that has become damaged by osteoarthritis, surgeons can isolate and resurface only the arthritic portion of the knee without compromising the healthy bone and tissue surrounding it. The procedure is performed through a 2-3” incision, as opposed to the 8” or larger incision required for traditional total knee replacement surgery.
The surgeon can pre-operatively determine the damaged area of the bone to be removed, and plan the precise alignment and placement of the resurfacing implant specific to the patient’s anatomy. As surgeons use the robotic arm to resurface the knee for placement of the implants, RIO provides real-time interoperative visual, tactile, and auditory feedback.
The RESTORIS® MCK Multi Compartmental Knee System features femoral and patellofemoral components that nest together and allow for smooth patella tracking and transitioning. The RESTORIS inlay implant is designed to restore the natural function of the knee by playing the role of the cartilage lost to osteoarthritis. It is comprised of two components: the femoral component (affixed to the femur bone) and the tibial component (affixed to the tibia bone).
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Acrobot Surgeon-Controlled System
London-based Acrobot provides surgical systems for computerassisted 3D planning, surgical navigation, and surgeon-controlled robotic surgery, particularly for knee and hip implants. (Acrobot products currently are not available in the U.S.) The patient has a pre-operative CT scan and the CT data files are processed using the Acrobot Modeller™ Software to produce a 3D model of the anatomy. This can then be imported by the surgeon into Acrobot Planner™ software, which produces an individual patient plan showing the exact positioning and size of the implant required. Planning can be performed pre-operatively or immediately prior to surgery, depending on surgeon preference.
The patient-specific plan is then loaded into the Acrobot Navigator, a non-optical/non-electromagnetic navigation system that does not interfere with the surgical site and is housed within a cart. The surgeon can see the actual versus planned position of each instrument to achieve accurate bone preparation. The system uses mechanical tracking arms attached through the main incision to monitor the position of the patient relative to the instrumentation.
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ROBODOC Orthopedic Surgical System
The ROBODOC® surgical system from CUREXO Technology Corp. of Sacramento, CA, allows surgeons to pre-operatively plan their surgery in a 3D virtual space and then execute the surgery exactly as planned. An early prototype of the ROBODOC system was developed in 1986 when IBM’s Thomas J. Watson Research Center and researchers at the University of California, Davis, began collaborative development of a system for Total Hip Arthroplasty (THA). The system includes ORTHODOC®, a computer workstation equipped with proprietary software for 3D preoperative surgical planning; and the ROBODOC Surgical Assistant, a computer- controlled surgical robot used for cavity and surface preparation for hip and knee replacements. ORTHODOC converts the CT scan of the patient’s joint into a 3D bone image, which can be manipulated by the surgeon to view bone and joint characteristics. A prosthetic image is selected from ORTHODOC’s digital library; the surgeon manipulates the 3D model against the CT bone image, allowing for optimal prosthetic selection and alignment. This virtual surgery creates a preoperative plan customized for each patient. In a primary THA procedure, the surgeon plans the femoral cavity preparation on the ORTHODOC, and can determine the specific brand, size, and type of prosthesis. The preoperative plan created on ORTHODOC is electronically transferred to the ROBODOC, which can precisely execute the plan. Using controlled, gentle pressure, the ROBODOC can mill the bone with submillimeter accuracy as specified by the preoperative plan. The robot mills cavities for hip implants, removes bone cement for revision surgeries, and planes the femoral and tibia surfaces for knee implants. Visit http://info.hotims.com/22916-149 for more information on ROBODOC.
The Future of Surgical Robotics
Many of the systems currently in use are still in early generations, and there seems to be no limit to the types of surgeries that will eventually be performed using robotic assistance. There are plans by some manufacturers of surgical robotics equipment to expand capabilities of the systems into procedures such as spine and cranial surgeries. Said Dr. Grossi, “I’m a believer in technology, and the systems are only going to get better.”