Robotic Surgery Systems

Abstract

For many people, the term “robotic surgery” likely evokes one of two images. One is Asimo, the Honda robot, performing a complex heart-valve replacement with the precision and finesse of the most skilled surgeon. The other is more along the lines of an industrial robot found welding on an automotive assembly line—performing surgery by rote programming on scores of patients in a row, just like in a factory. Neither is the case. Robotic surgery is, by some accounts, the next level of minimally invasive surgery.Conventional invasive surgery involves a large incision in the body to gain access to the area and organ of interest. For example, in a conventional gallbladder removal, the surgeon first performs a laparotomy, which is an incision, usually a large one, through the abdominal wall to gain access to the interior of the torso. The problem with a laparotomy is that it is very stressful physiologically and exposes large portions of the patient's abdominal cavity to infection. Additionally, because the incision is so large, and the surgeon needs access to a large part of the patient's interior, the surgery is characterized by a relatively large amount of trauma to the surrounding tissue, blood loss, and postoperative pain and discomfort coupled with a prolonged healing period. To overcome the problems and side effects of the laparotomy, minimally invasive surgery was developed.Minimally invasive surgery accesses the chest or abdomen through several smaller incisions, each one typically half an inch long. Each smaller incision has a port, or a combination trocar/port is used to make the incision, to protect the surrounding tissue while a particular device is inserted through the hole. The most common items inserted are an endoscope connected to a camera, a light source (which may be part of the other devices), an insufflator, and an instrument with one or more operating channels. In the case of minimally invasive gallbladder removal, now called a laparoscopic cholecystectomy, all the associated steps (draining the gall bladder, severing it from the ducts, and removing the empty bladder) are performed through the operating channel using specially adapted instruments. In minimally invasive surgery, as few as three or four small incisions can take the place of the much larger laparotomy incision. Some surgeons also perform this procedure as “scarless surgery” by accessing the abdomen through the navel and using a specialized operating endoscope with integral illumination and operating channels. Although there technically is a scar, observers might be hard pressed to find it as it is hidden in the folds of the navel. As one would expect, the smaller incisions mean less trauma to the body as a whole, reduced blood loss, and minimal discomfort, all of which equate to a shorter healing period.Minimally invasive surgery techniques are primarily responsible for the increase in “same day surgery” procedures. Cases employing laparatomies frequently required a one to two week hospital stay for observation (in the event of complications like hemorrhage) and recuperation. Now that time is reduced to a few hours of post-recovery room rest, and patients are discharged later that same day to finish their recuperation at home.As good as minimally invasive surgery is, it also has some drawbacks. Because the space inside the torso is very limited, and the operation is performed with a minimum of disturbance to the surrounding tissue, it can be difficult for the surgeon to visualize the surgical field and manipulate the instruments. In such a small space, minute but precise movements of the instruments are required to ensure the operation remains trouble free. Poor visibility in the surgical field has led to problems ranging from accidentally nicking adjacent tissue to more serious matters, such as cutting a liver duct in addition to the bile duct or accidentally severing an artery beyond the surgeon's field of view. Robotic surgery systems are designed to overcome these challenges and provide yet another major advancement in surgery. To date, robotic surgery systems are viewed warily in many healthcare facilities, partially due to their high cost—$1.25 million and up—and to the limited types of procedures they may perform. Despite these obstacles, facilities in 2012 performed approximately 450,000 robotic surgical procedures in more than 2,000 facilities worldwide.Robotic surgery systems are expensive, and they are approved by the U.S. Food and Drug Administration (FDA) for only a handful of procedures in cardiac, gynecology, otolaryngology, pediatric, and urology specialties. Second, as of this writing, there are only three models of systems approved for sale and use in the United States, and all of them are made by a single company. Their high price and relatively limited number of approved applications makes them impractical for many small rural medical facilities. They are found more often at tertiary referral facilities, where the necessary specialists and case workload supports their utilization. Because there is only a single manufacturer, much of the information on the three models is considered proprietary. However, some interesting information about them is available if one digs deep enough.All three robotic surgery systems employ a physician's console with computerized controls and a patient side cart containing up to four instrument arms, including an endoscope connected to a fiber optic camera. The surgeon's console is located within several yards of the operating table and patient side cart. Unlike traditional endoscopic viewing, with robotic systems, the surgeon sits and looks into a large hooded viewing area. The hood blocks outside light and facilitates concentration. The high-resolution video monitors inside the hood provide the surgeon a stereo image magnified tenfold of the operating site from the endoscope mounted on the patient side cart. This video system places the surgeon inside the patient looking at the surgical site from only a few millimeters away, with the instruments and images directly in front of the surgeon, between his or her arms. Even current minimally invasive surgery requires the surgeon to look up and away from the patient and his instruments to view the surgical site on a monitor mounted near the operating table. Some surgeons believe that this view is superior to that provided by even conventional surgery. At the surgeon's left and right hands are joystick-like controls with additional controls mounted at his feet. A “bumper” device in the hand controls provides tactile feedback when using certain tissue grasping instruments. Armrests help to minimize fatigue during the operation. The hand and foot controls manipulate the operating instruments attached to the patient side cart. Additionally, the surgeon is capable of zooming in to obtain a better view of details at the surgical site.The computer forms the interface for the surgeon's hand and foot movements and translates those into movements of the instruments attached to the patient side cart. Two important characteristics of the software is that it controls the zoom of the video and reduces the surgeon's movements to compensate for the magnified view of the surgical field. Lastly, the computer buffers the surgeon's movements to compensate for any minor tremors and provides positive feedback to the bumpers when grasping something.The patient side cart replaces the table-side surgeon and looks like a cross between a praying mantis and the multiarmed Hindu goddess Kali. The cart contains as many as four arms, folded like the forelegs of a praying mantis when retracted to the parked position, arrayed across its top to allow full movement of each arm in all planes. Each arm is capable of holding one of the specially designed or adapted operating instruments—a miniaturized surgical camera, wristed scissors, scalpels, forceps—all designed to help with delicate dissection and reconstruction deep inside the body. As the operation progresses, the instruments are changed by the secondary surgeon or by a trained operating room nurse or technician as required.Maintenance services should be scheduled and tracked uniquely for each system with equal consideration given to liability, the initial cost, and the proprietary nature of the hardware and software. Each system should have a detailed maintenance history. Owing to both the uniqueness and proprietary components of robotic surgery systems, a maintenance contract with the manufacturer is recommended. As competitive products enter the field of robotic surgery, options other than full-service contracts may be viable in the future. With manufacturer training, a first-call contract would be the best mix of in-house and contractor maintenance capabilities.There are no specific regulations covering robotic surgery systems. As always, it is crucial to follow regulations promulgated by the FDA.There have been reported equipment malfunctions in robotic surgery systems that impact the risk manager. Malfunctions of the arms, console, the optics, the computer, or any of the instruments during an operation can result in disaster for the patient. The FDA's Manufacturer and User Facility Device Experience (MAUDE) database contains a number of incident reports and complaints about these systems. In 2012, there were 282 adverse event reports associated with these systems at more than 2,000 hospitals. Before allowing surgeons to use robotic surgery systems, hospitals typically require many hours of simulator training, akin to requiring flight simulator and actual flying hours prior to awarding a pilot's rating. Aside from the few computer-related hardware problems, most of the risk management issues associated with these systems are totally in the surgeon's hands. Although tremor-like movements are filtered out, gross unintended hand movements are replicated by the system, which could result in a surgical error. Postoperative infection is always a concern with any invasive procedure, and robotic surgery is no exception. Although the surgery site or sites are smaller, infection either at the point of intrusion or deep within the torso is still a possibility.The most common problems reported with these systems are blown fuses, damaged cannulae, system “lockups,” and operational failure due to software issues. The first two can be can be resolved by in-house biomeds and nursing staff. Rebooting the system can resolve a software lockup, but this can be problematic if a computer lockup occurs repeatedly, especially during a case. Since contract maintenance is recommended, in-house biomeds will rarely if ever be called in to troubleshoot a problem.At this time, no additional training or equipment is necessary to service robotic surgery systems. Because there is only one manufacturer of this product, contract maintenance is the only sensible way to service these systems. As more manufacturers enter the field of robotic surgery, it's possible that service options could well include something other than a full-service contract. When this occurs, a first-call maintenance contract is the method of choice provided manufacturer training is available. Unlike a typical first-call maintenance agreement, such a contract also should cover software and firmware updates. Additionally, it should contain negotiated prices for system upgrades and other options when needed. Although current system designs are proprietary to the sole manufacturer of robotic surgery systems, future systems may employ, in addition to their computer and electronics components, principles of fluidic and vacuum systems to manipulate the arms, hands, and instruments. Biomeds servicing this equipment must be familiar with these systems and generally well versed in all disciplines of biomedical equipment maintenance.While there is only one manufacturer marketing robotic surgery systems in the United States, more are sure to follow. At this time, the field is wide open for improvements. For example, one system currently under development promises to provide both visible light and ultrasound images of the surgical site. This feature will allow the surgeon to see not only the surface, but also the internal structure of the tissue. Another area needing further development is that of tactile feedback. Current units only provide a vibrating indicator of the pressure being exerted. Future instruments may well provide real-time, pressure-proportionate tactile feedback to the surgeon.