Robotic Surgery: Applications, Limitations, and Impact on Surgical Education

Introduction

The 1990s have witnessed the so-called laparoscopic revolution in which many operations were adapted from the traditional open surgery to the minimal access technique.[1] Shorter hospital stays, reduced postoperative pain, lower incidence of wound infections, and better cosmetic outcomes have made operations, such as laparoscopic cholecystectomy, the standard of care for cholelethiasis.[1–4] Favorable results prompted surgeons to attempt to develop minimally invasive techniques for most surgical procedures. However, many complex procedures (eg, pancreatectomy) proved difficult to learn and to perform laparoscopically due to technical limitations inherent in laparoscopic surgery.[1] For example, the video camera held by the assistant was unstable and gave a limited 2-dimensional vision of the field, and the primary surgeon was forced to adopt awkward positions to operate with straight laparoscopic instruments, limiting maneuvering.[1,2,5] At some point, the growth of the laparoscopic field reached its ostensible plateau, and it seemed that only a new technologic leap could spur further development.

Since the beginning of the 21st century, the emergence of innovative technologies made further advances in minimal access surgery possible. Robotic surgery and telepresence surgery effectively addressed the limitations of laparoscopic and thoracoscopic procedures, thus revolutionizing minimal access surgery.[1,2] Robotic surgery is expected to continue to comprise a growing part of surgery.[6,7] It is envisaged that “almost all surgery can and will be performed by robotic surgery in the future.[5]” Thus, robotic surgery will not only require special training; it will also change the existing surgical training pattern and reshape the learning curve of residents by offering new solutions, such as robotic surgical simulators and robotic telementoring.[1,8]

What Is Robotic Surgery?

A surgical robot is a self-powered, computer-controlled device that can be programmed to aid in the positioning and manipulation of surgical instruments, enabling the surgeon to carry out more complex tasks.[1] Systems currently in use are not intended to act independently from human surgeons or to replace them.[9] Instead, these machines act as remote extensions completely governed by the surgeon and thus are best described as master-slave manipulators.[1] Two master-slave systems have received approval by the US Food and Drug Administration (FDA) and are in use[1,5] – the da Vinci Surgical System (Intuitive Surgical, Mountain View, California)[10,11] and the ZEUS system (Computer Motion, Goleta, California).[1,12] Each system has 2 basic components linked together through data cables and a computer:[1–3,5]

• The surgeon's master console is the robot's user interface that provides the master surgeon with the following functions:

  • A 3-dimensional view of the surgical field relayed from an endoscopic camera inside the patients body in control of the robot that creates a sense of being “immersed” into the surgical field.
  • Master manipulators, which are handles or joysticks that the surgeon uses to make surgical movements that are then translated into real-time movements of the slave manipulators docked on the patient. Motion scaling (conversion of large natural movements to ultraprecise micromovements)[13] and tremor filtering increase accuracy and precision of the surgeon's movements.[14]
  • A control panel to adjust other functions, such as focusing of the camera, motion scaling, and accessory units.

• Patient-side slave robotic manipulators are robotic arms that manipulate the surgical instruments and the camera through laparoscopic ports connected to the patient's body. The da Vinci system handles surgical instruments with microarticulations near the tip (EndoWrist) that can duplicate motions of the human wrist, including rotation (7 degrees of freedom, ie, the greatest possible motion around a joint).[1,11]

Clinical Applications of Robotic Surgery

Robotic surgery has successfully addressed the limitations of traditional laparoscopic and thoracoscopic surgery,[1–3] thus allowing completion of complex and advanced surgical procedures with increased precision in a minimally invasive approach. In contrast to the awkward positions that are required for laparoscopic surgery, the surgeon is seated comfortably on the robotic control consol, an arrangement that reduces the surgeon's physical burden.[15] Instead of the flat, 2-dimensional image that is obtained through the regular laparoscopic camera, the surgeon receives a 3-dimensional view that enhances depth perception; camera motion is steady and conveniently controlled by the operating surgeon via voice-activated or manual master controls. Also, manipulation of robotic arm instruments improves range of motion compared with traditional laparoscopic instruments, thus allowing the surgeon to perform more complex surgical movements (Table 1).[1–3,12–14]

Table 1.

Laparoscopic Limitations/Robotic Solutions

Laparoscopic Problems/Limitations	Robotic Surgery Solutions/Potential
Two-dimensional vision of surgical field displayed on the monitor impairs depth perception	Binocular systems and polarizing filters create 3-dimensional view of the field
Movements are counterintuitive (ie, moving the instrument to the right appears to the left on the screen due to mirror-image effect)	Movements are intuitive (ie, moving the control to the right produces a movement to the right on the viewer)
Unstable camera held by an assistant	Surgeon controls camera held in position by robotic arm, allowing solo surgery
Diminished degrees of freedom of straight laparoscopic instruments	Microwrists near the tip that mimic the motion of the human wrist
Surgeon forced to adopt uncomfortable postures during operation	Superior operative ergonomics: surgeon comfortably seated on the control console
Steep learning curve	Shorter learning curve

In a relatively short time, robotic procedures spanning the whole spectrum of surgery have been successfully executed (Table 2).[1,3,16–38] Initial results show that mortality, morbidity, and hospital stay compare favorably to conventional laparoscopic operations.[39] However, only a limited number of randomized, prospective studies that compare outcomes of robotic techniques with conventional methods exist.[40,41] More procedure-specific, randomized trials need to be performed before robotic surgery can find its way into everyday surgical practice.[19,42]

Table 2.

Clinical Applications of Robotic Surgery

Field	Operations Performed via Robotic Surgery
Robotic gastrointestinal surgery[1, 16–20]	1997: Himpens et al.[17] – first robotic cholecystectomy
	Antireflux operations, Heller's myotomy, gastric bypass, gastrojejunostomy, esophojectomy, gastric banding colectomy, splenectomy, adrenalectomy, and pancreatic resection reported to date
Robotic urologic surgery[21–24]	Radical robotic prostatectomy is the most common operation performed robotically and is gaining widespread recognition in the United States and EuropeNephrectomy and pelvic lymph node dissection also reported
Robotic gynecologic surgery[25–28]	Robotic hysterectomy, salpingo-oophorectomy, and microsurgical fallopian tube reanastomosis
Robotic cardiothoracic surgery[29–34]	Surgical robots allow cardiothoracic surgeons to perform complex cardiothoracic procedures while avoiding the significant morbidity of sternotomy and thoracotomyHundreds of robotic coronary bypasses have been performed to dateMitral valve repairs, atrial spetal defect repair, pericardiectomy, lobectomies, and tumor enucleations
Robotic oncologic surgery[3]	Esophageal tumors, gastric cancer, colon cancer, thymoma, and retromediastinal tumors
Robotic pediatric surgery[35–38]	Pyeloplasty for ureteropelvic junction obstruction, antireflux procedures for gastroesophageal reflux disease, and pediatric congenital heart diseases, such as ligation of patent ductus arteriosus

Limitations of Robotic Surgery

Although rapidly developing, robotic surgical technology has not achieved its full potential owing to a few limitations. Cost-effectiveness is a major issue[43]; 2 recent studies comparing robotic procedures with conventional operations showed that although the absolute cost for robotic operations was higher, the major part of the increased cost was attributed to the initial cost of purchasing the robot (estimated at $1,200,000) and yearly maintenance ($100,000).[43,44] Both factors are expected to decrease as robotic systems gain more widespread acceptance. However, it is conceivable that further technical advances may at first drive prices even higher.[45] Decreasing operative time and hospital stay will also contribute to the cost-effectiveness of robotic surgery.[44]

Other drawbacks to robotic surgery include the bulkiness of the robotic equipment currently in use.[1,7] Lack of tactile and force feedback to the surgeon is another major problem,[1,19] for which haptics (ie, systems that recreate the “feel” of tissues through force feedback) offers a promising, although as yet unrealized, solution.[46,47]

Telepresence Surgery

Telepresence surgery and robotic telementoring are 2 revolutionary applications achieved by linking a robot to a telecommunication system, such as SOCRATES (Computer Motion).[1,3] In telerobotic procedures, the surgeon operates from the surgeon's console, which is thousands of miles away from the slave robotic arm mounted on the patient; the surgeon's commands are relayed to the slave manipulator via fiber-optic cables.[1] The first major transatlantic surgery was a telerobotic cholecystectomy performed by surgeons in New York, NY, on a patient in Strasbourg, France, in 2001.[48,49] Since then, many telerobotic operations have been performed. Telepresence surgery allows surgeons to operate wherever their skills are needed without being in direct contact with the patient. Although this virtual surgery has many implications, good and bad, one touted as potentially beneficial is the delivery of surgical care in medically underserved areas.[50,51] However, with a purchase cost around $1 million, a surgical robot is too expensive for places where it is most needed. For example, in Africa the average annual per capita healthcare expenditure is around $6.[52] When finances are not limiting, robotic surgery presents the potential for delivering surgical care to patients who have no direct access to a surgeon. The National Aeronautics and Space Administration (NASA) is exploring the use of surgical robots for emergency surgery on astronauts in a submarine to simulate conditions in space in a project called NEEMO 7.[53] The Pentagon is investing $12 million in a project to develop a “trauma pod” surgical robot to operate on soldiers wounded away from home.[54] A “concept video” extrapolating how such systems can evacuate wounded soldiers under enemy fire and then operate on them is available online.[55]

In telementoring, an expert surgeon guides another surgeon operating miles away; both surgeons “share” the view of the surgical field and control of the robotic system and communicate via microphones. Telementoring can potentially be used for teaching surgical skills to junior surgeons all around the world by expert colleagues.[56–59]

Robotic Surgery and Surgical Education

Despite many technologic leaps, surgical training has stayed more or less unchanged for more than a century. Surgeons in training have always had to gain operative experience through “supervised trial and error” on real patients. This approach makes surgical training completely dependent on the actual case load, prolongs surgical training, and compromises patients' safety.[1] Robotic surgery will create a new medium for acquisition of surgical skills through simulation of all operations that can be done via the robot. Surgeons can use surgical robots to practice operations on 3-dimensional, virtual-reality visual simulations and soft-tissue models that recreate the textures of human tissues through force feedback (haptics).[60,61] Image-guided simulations will allow surgeons to practice procedures on 3-dimensional reconstructions of the anatomy of the actual patients who they plan to operate on the next day.[62–64] In all of these simulations, trainees can be guided through telementoring. Telepresence surgery has been also successfully used in teaching surgical skills to third-year medical students.[65]

These systems are expected to significantly enhance the learning curve, allowing trainees to acquire surgical skills in a short time while improving patient safety by reducing surgical errors.[1] Ultimately, these applications will be integral to the training and licensing of surgeons and will provide objective means for assessment of surgical skills.[66]

Robotic technology is expected to play an increasingly important role in the future of surgery. However, most residency programs in the United States have not placed adequate emphasis on training in robotic surgery.[1] A survey in 2002 showed that only 23% of surgery program directors have plans to incorporate robotics into their programs.[67] In 2003, another survey by the same group showed that although 57% of surgical residents demonstrated high interest in robotic surgery, the majority (80%) did not have a robotic training program in their institutions.[68] A few academic centers have developed formal didactics to train teams in robotic surgery.[69]

Ensuring competency to perform robotic procedures is left to individual hospitals. It is expected that as formal training in robotic surgery develops, more standardized credentials will be required to obtain robotic surgical privileges.[45,70]

Conclusion

Although still in its infancy, robotic surgery is a cutting-edge development in surgery that will have far-reaching implications. While improving precision and dexterity, this emerging technology allows surgeons to perform operations that were traditionally not amenable to minimal access techniques. As a result, the benefits of minimal access surgery may be applicable to a wider range of procedures. Safety has been well established, and many series of cases have reported favorable outcomes. However, randomized, controlled trials comparing robotic-assisted procedures with laparoscopic or open techniques are generally lacking.

Telerobotic surgery stands out as a way of delivering surgical care to patients who have no direct access to a surgeon; however, costs are prohibitive to the spread of such technology to underserved areas that need it most. Even in the United States, surgical robots are mainly available in large academic centers. The issues of cost, technical drawbacks, and clinical effectiveness need to be resolved before robotic procedures can become mainstream, everyday surgical procedures.

New technologies, such as virtual reality, haptics, and telementoring, can powerfully ally with surgical robots to create a new medium for acquisition and assessment of surgical skills through simulation of all operations that can be done via the robot. Performance of robotic procedures requires specialized training. However, the majority of residency programs in the United States do not provide formal training in robotic surgery skills. Students, residents, and residency programs should strive to keep up with this new development in surgical technology that is likely to reshape the way we practice surgery.

Readers are encouraged to respond to George Lundberg, MD, Editor of MedGenMed, for the editor's eye only or for possible publication via email: glundberg@medscape.net.