Download Robotic Surgery Essay and more Essays (university) Social Theory in PDF only on Docsity!
R EVIEW
Robotic Surgery
A Current Perspective
Anthony R. Lanfranco, BAS, Andres E. Castellanos, MD, Jaydev P. Desai, PhD,*† and
William C. Meyers, MD
Objective: To review the history, development, and current appli- cations of robotics in surgery. Background: Surgical robotics is a new technology that holds significant promise. Robotic surgery is often heralded as the new revolution, and it is one of the most talked about subjects in surgery today. Up to this point in time, however, the drive to develop and obtain robotic devices has been largely driven by the market. There is no doubt that they will become an important tool in the surgical armamentarium, but the extent of their use is still evolving. Methods: A review of the literature was undertaken using Medline. Articles describing the history and development of surgical robots were identified as were articles reporting data on applications. Results: Several centers are currently using surgical robots and publishing data. Most of these early studies report that robotic surgery is feasible. There is, however, a paucity of data regarding costs and benefits of robotics versus conventional techniques. Conclusions: Robotic surgery is still in its infancy and its niche has not yet been well defined. Its current practical uses are mostly confined to smaller surgical procedures.
( Ann Surg 2004;239: 14 –21)
R
obotic surgery is a new and exciting emerging technology that is taking the surgical profession by storm. Up to this point, however, the race to acquire and incorporate this emerg- ing technology has primarily been driven by the market. In addition, surgical robots have become the entry fee for centers wanting to be known for excellence in minimally invasive
surgery despite the current lack of practical applications. There- fore, robotic devices seem to have more of a marketing role than a practical role. Whether or not robotic devices will grow into a more practical role remains to be seen. Our goal in writing this review is to provide an objec- tive evaluation of this technology and to touch on some of the subjects that manufacturers of robots do not readily disclose. In this article we discuss the development and evolution of robotic surgery, review current robotic systems, review the current data, discuss the current role of robotics in surgery, and finally we discuss the possible roles of robotic surgery in the future. It is our hope that by the end of this article the reader will be able to make a more informed decision about robotic surgery before “chasing the market.”
BACKGROUND AND HISTORY OF SURGICAL
ROBOTS
Since 1921 when Czech playwright Karel Capek intro- duced the notion and coined the term robot in his play Rossom’s Universal Robots , robots have taken on increas- ingly more importance both in imagination and reality.1, Robot, taken from the Czech robota , meaning forced labor, has evolved in meaning from dumb machines that perform menial, repetitive tasks to the highly intelligent anthropomor- phic robots of popular culture. Although today’s robots are still unintelligent machines, great strides have been made in expanding their utility. Today robots are used to perform highly specific, highly precise, and dangerous tasks in indus- try and research previously not possible with a human work force. Robots are routinely used to manufacture microproces- sors used in computers, explore the deep sea, and work in hazardous environment to name a few. Robotics, however, has been slow to enter the field of medicine. The lack of crossover between industrial robotics and medicine, particularly surgery, is at an end. Surgical robots have entered the field in force. Robotic telesurgical machines have already been used to perform transcontinental cholecys- tectomy.3,4^ Voice-activated robotic arms routinely maneuver endoscopic cameras, and complex master slave robotic sys- tems are currently FDA approved, marketed, and used for a
From the *Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia and Drexel University College of Medicine, Philadelphia, Pennsylvania. This material is based upon work supported by the National Science †Foundation under Grant No. 0079830 and Grant No. 0133471. Reprints: Andres E Castellanos, MD, Assistant Professor, Department of Surgery, Drexel University College of Medicine. Mail Stop 413, 245 N. 15th Street, Philadelphia PA 19102. E-mail: Andres.E.Castellanos@ Drexel.edu. Copyright © 2003 by Lippincott Williams & Wilkins ISSN: 0003-4932/04/23901- DOI: 10.1097/01.sla.0000103020.19595.7d
14 Annals of Surgery • Volume 239, Number 1, January 2004
variety of procedures. It remains to be seen, however, if history will look on the development of robotic surgery as a profound paradigm shift or as a bump in the road on the way to something even more important. Paradigm shift or not, the origin of surgical robotics is rooted in the strengths and weaknesses of its predecessors. Minimally invasive surgery began in 1987 with the first laparoscopic cholecystectomy. Since then, the list of proce- dures performed laparoscopically has grown at a pace con- sistent with improvements in technology and the technical skill of surgeons.^5 The advantages of minimally invasive surgery are very popular among surgeons, patients, and in- surance companies. Incisions are smaller, the risk of infection is less, hospital stays are shorter, if necessary at all, and convalescence is significantly reduced. Many studies have shown that laparoscopic procedures result in decreased hos- pital stays, a quicker return to the workforce, decreased pain, better cosmesis, and better postoperative immune func- tion.^6 –^8 As attractive as minimally invasive surgery is, there are several limitations. Some of the more prominent limita- tions involve the technical and mechanical nature of the equipment. Inherent in current laparoscopic equipment is a loss of haptic feedback (force and tactile), natural hand-eye coordination, and dexterity. Moving the laparoscopic instru- ments while watching a 2-dimensional video monitor is somewhat counterintuitive. One must move the instrument in the opposite direction from the desired target on the monitor to interact with the site of interest. Hand-eye coordination is therefore compromised. Some refer to this as the fulcrum effect.^9 Current instruments have restricted degrees of mo- tion; most have 4 degrees of motion, whereas the human wrist and hand have 7 degrees of motion. There is also a decreased sense of touch that makes tissue manipulation more heavily dependent on visualization. Finally, physiologic tremors in the surgeon are readily transmitted through the length of rigid instruments. These limitations make more delicate dissec- tions and anastomoses difficult if not impossible.^10 The mo- tivation to develop surgical robots is rooted in the desire to overcome the limitations of current laparoscopic technologies and to expand the benefits of minimally invasive surgery. From their inception, surgical robots have been envi- sioned to extend the capabilities of human surgeons beyond the limits of conventional laparoscopy. The history of robot- ics in surgery begins with the Puma 560, a robot used in 1985 by Kwoh et al to perform neurosurgical biopsies with greater precision.6,11^ Three years later, Davies et al performed a transurethral resection of the prostate using the Puma 560.^12 This system eventually led to the development of PROBOT, a robot designed specifically for transurethral resection of the prostate. While PROBOT was being developed, Integrated Surgical Supplies Ltd. of Sacramento, CA, was developing ROBODOC, a robotic system designed to machine the femur
with greater precision in hip replacement surgeries.^1 RO- BODOC was the first surgical robot approved by the FDA. Also in the mid-to-late 1980s a group of researchers at the National Air and Space Administration (NASA) Ames Research Center working on virtual reality became interested in using this information to develop telepresence surgery.^1 This concept of telesurgery became one of the main driving forces behind the development of surgical robots. In the early 1990s, several of the scientists from the NASA-Ames team joined the Stanford Research Institute (SRI). Working with SRI’s other robotocists and virtual reality experts, these scientists developed a dexterous telemanipulator for hand surgery. One of their main design goals was to give the surgeon the sense of operating directly on the patient rather than from across the room. While these robots were being developed, general surgeons and endoscopists joined the development team and realized the potential these systems had in ameliorating the limitations of conventional laparo- scopic surgery. The US Army noticed the work of SRI, and it became interested in the possibility of decreasing wartime mortality by “bringing the surgeon to the wounded soldier—through telepresence.”^1 With funding from the US Army, a system was devised whereby a wounded soldier could be loaded into a vehicle with robotic surgical equipment and be operated on remotely by a surgeon at a nearby Mobile Advanced Surgical Hospital (MASH). This system, it was hoped, would decrease wartime mortality by preventing wounded soldiers from exsan- guinating before they reached the hospital. This system has been successfully demonstrated on animal models but has not yet been tested or implemented for actual battlefield casualty care. Several of the surgeons and engineers working on surgical robotic systems for the Army eventually formed commercial ventures that lead to the introduction of robotics to the civilian surgical community.^1 Notably, Computer Mo- tion, Inc. of Santa Barbara, CA, used seed money provided by the Army to develop the Automated Endoscopic System for Optimal Positioning (AESOP), a robotic arm controlled by the surgeon voice commands to manipulate an endoscopic camera. Shortly after AESOP was marketed, Integrated Sur- gical Systems (now Intuitive Surgical) of Mountain View, CA, licensed the SRI Green Telepresence Surgery system. This system underwent extensive redesign and was reintro- duced as the Da Vinci surgical system. Within a year, Computer Motion put the Zeus system into production.
CURRENT ROBOTIC SURGICAL SYSTEMS
Today, many robots and robot enhancements are being researched and developed. Schurr et al at Eberhard Karls University’s section for minimally invasive surgery have developed a master-slave manipulator system that they call ARTEMIS.^13 This system consists of 2 robotic arms that are controlled by a surgeon at a control console. Dario et al at the
Annals of Surgery • Volume 239, Number 1, January 2004 Robotic Surgery
These robotic systems enhance dexterity in several ways. Instruments with increased degrees of freedom greatly enhance the surgeon’s ability to manipulate instruments and thus the tissues. These systems are designed so that the surgeons’ tremor can be compensated on the end-effector motion through appropriate hardware and software filters. In addition, these systems can scale movements so that large movements of the control grips can be transformed into micromotions inside the patient.^6 Another important advantage is the restoration of proper hand-eye coordination and an ergonomic position. These robotic systems eliminate the fulcrum effect, making
instrument manipulation more intuitive. With the surgeon sitting at a remote, ergonomically designed workstation, current sys- tems also eliminate the need to twist and turn in awkward positions to move the instruments and visualize the monitor. By most accounts, the enhanced vision afforded by these systems is remarkable. The 3-dimensional view with depth perception is a marked improvement over the conven- tional laparoscopic camera views. Also to one’s advantage is the surgeon’s ability to directly control a stable visual field with increased magnification and maneuverability. All of this creates images with increased resolution that, combined with the increased degrees of freedom and enhanced dexterity,
TABLE 2. Advantages and Disadvantages of Robot-Assisted Surgery Versus Conventional Surgery
Human strengths Human limitations Robot strengths Robot limitations
● Strong hand–eye coordination
● Limited dexterity outside natural scale
● Good geometric accuracy ● No judgement
● Dexterous ● Prone to tremor and fatigue ● Stable and untiring ● Unable to use qualitative information ● Flexible and adaptable ● Limited geometric accuracy ● Scale motion ● Absence of haptic sensation ● Can integrate extensive and diverse information
● Limited ability to use quantitative information
● Can use diverse sensors in control
● Expensive
● Rudimentary haptic abilities ● Limited sterility ● May be sterilized ● Technology in flux ● Able to use qualitative information
● Susceptible to radiation and infection
● Resistant to radiation and infection
● More studies needed
● Good judgment ● Easy to instruct and debrief
TABLE 1. Advantages and Disadvantages of Conventional Laparoscopic Surgery Versus Robot-Assisted Surgery
Conventional Laparoscopic surgery Robot-assisted surgery
Advantages Well-developed technology 3-D visualization Affordable and ubiquitous Improved dexterity Proven efficacy Seven degrees of freedom Elimination of fulcrum effect Elimination of physiologic tremors Ability to scale motions Micro-anastomoses possible Tele-surgery Ergonomic position Disadvantages Loss of touch sensation Absence of touch sensation Loss of 3-D visualization Very expensive Compromised dexterity High start-up cost Limited degrees of motion May require extra staff to operate The fulcrum effect New technology Amplification of physiologic tremors Unproven benefit
Annals of Surgery • Volume 239, Number 1, January 2004 Robotic Surgery
greatly enhances the surgeon’s ability to identify and dissect anatomic structures as well as to construct microanastomoses.
DISADVANTAGES OF ROBOT-ASSISTED
SURGERY
There are several disadvantages to these systems. First of all, robotic surgery is a new technology and its uses and efficacy have not yet been well established. To date, mostly studies of feasibility have been conducted, and almost no long-term follow up studies have been performed. Many procedures will also have to be redesigned to optimize the use of robotic arms and increase efficiency. However, time will most likely remedy these disadvantages. Another disadvantage of these systems is their cost. With a price tag of a million dollars, their cost is nearly prohibitive. Whether the price of these systems will fall or rise is a matter of conjecture. Some believe that with im- provements in technology and as more experience is gained with robotic systems, the price will fall.^6 Others believe that improvements in technology, such as haptics, increased processor speeds, and more complex and capable software will increase the cost of these systems.^9 Also at issue is the problem of upgrading systems; how much will hospitals and healthcare organizations have to spend on upgrades and how often? In any case, many believe that to justify the purchase of these systems they must gain widespread multi- disciplinary use.^9 Another disadvantage is the size of these systems. Both systems have relatively large footprints and relatively cum- bersome robotic arms. This is an important disadvantage in today’s already crowded-operating rooms.^9 It may be difficult for both the surgical team and the robot to fit into the operating room. Some suggest that miniaturizing the robotic arms and instruments will address the problems associated with their current size. Others believe that larger operating suites with multiple booms and wall mountings will be needed to accommodate the extra space requirements of robotic surgical systems. The cost of making room for these robots and the cost of the robots themselves make them an especially expensive technology. One of the potential disadvantages identified is a lack of compatible instruments and equipment. Lack of certain in- struments increases reliance on tableside assistants to perform part of the surgery.^6 This, however, is a transient disadvan- tage because new technologies have and will develop to address these shortcomings. Most of the disadvantages identified will be remedied with time and improvements in technology. Only time will tell if the use of these systems justifies their cost. If the cost of these systems remains high and they do not reduce the cost of routine procedures, it is unlikely that there will be a robot in every operating room and thus unlikely that they will be used for routine surgeries
CURRENT CLINICAL APPLICATIONS AND
EARLY DATA
Several robotic systems are currently approved by the FDA for specific surgical procedures. As mentioned previ- ously, ROBODOC is used to precisely core out the femur in hip replacement surgery. Computer Motion Inc. of Goleta, CA, has 2 systems on the market. One, called AESOP, is a voice-controlled endoscope with 7 degrees of freedom. This system can be used in any laparoscopic procedure to enhance the surgeon’s ability to control a stable image. The Zeus system and the Da Vinci system have been used by a variety of disciplines for laparoscopic surgeries, including cholecys- tectomies, mitral valve repairs, radical prostatectomies, re- versal of tubal ligations, in addition to many gastrointestinal surgeries, nephrectomies, and kidney transplants. The num- ber and types of surgeries being performed with robots is increasing rapidly as more institutions acquire these systems. Perhaps the most notable use of these systems, however, is in totally endoscopic coronary artery grafting, a procedure for- merly outside the limitations of laparoscopic technology. The amount of data being generated on robotic surgery is growing rapidly, and the early data are promising. Many studies have evaluated the feasibility of robot-assisted sur- gery. One study by Cadiere et al evaluated the feasibility of robotic laparoscopic surgery on 146 patients.^20 Procedures performed with a Da Vinci robot included 39 antireflux procedures, 48 cholecystectomies, 28 tubal reanastomoses, 10 gastroplasties for obesity, 3 inguinal hernia repairs, 3 intrarectal procedures, 2 hysterectomies, 2 cardiac proce- dures, 2 prostatectomies, 2 artiovenous fistulas, 1 lumbar sympathectomy, 1 appendectomy, 1 laryngeal exploration, 1 varicocele ligation, 1 endometriosis cure, and 1 neosalpin- gostomy. This study found robotic laparoscopic surgery to be feasible. They also found the robot to be most useful in intra-abdominal microsurgery or for manipulations in very small spaces. They reported no robot related morbidity. Another study by Falcone et al tested the feasibility of robot-assisted laparoscopic microsurgical tubal anastomo- sis.^31 In this study, 10 patients who had previously undergone tubal sterilization underwent tubal reanastomosis. They found that the 19 tubes were reanastomosed successfully and 17 of the 19 were still patent 6 weeks postoperatively. There have been 5 pregnancies in this group so far. Margossian and Falcone also studied the feasibility of robotic surgery in complex gynecologic surgeries in pigs.^22 In this study, 10 pigs underwent adnexal surgery or hysterectomy using the Zeus robotic system. They found that robotic surgery is safe and feasible for complex gynecologic surgeries. In yet an- other study by Marescaux et al, the safety and feasibility of telerobotic laparoscopic cholecystectomy was tested in a prospective study of 25 patients undergoing the procedure.^33 Twenty-four of the 25 laparoscopic cholecystectomies were
Lanfranco et al Annals of Surgery • Volume 239, Number 1, January 2004
advances in ancillary products will continue. Already, the development of robotics is spurring interest in new tissue anastomosis techniques, improving laparoscopic instruments, and digital integration of already existing technologies. As mentioned previously, applications of robotic sur- gery are expanding rapidly into many different surgical dis- ciplines. The cost of procuring one of these systems remains high, however, making it unlikely that an institution will acquire more than one or two. This low number of machines and the low number of surgeons trained to use them makes incorporation of robotics in routine surgeries rare. Whether this changes with the passing of time remains to be seen.
THE FUTURE OF ROBOTIC SURGERY
Robotic surgery is in its infancy. Many obstacles and disadvantages will be resolved in time and no doubt many other questions will arise. Many question have yet to be asked; questions such as malpractice liability, credentialing, training requirements, and interstate licensing for tele-sur- geons, to name just a few. Many of current advantages in robotic assisted surgery ensure its continued development and expansion. For exam- ple, the sophistication of the controls and the multiple degrees of freedom afforded by the Zeus and da Vinci systems allow increased mobility and no tremor without comprising the visual field to make micro anastomosis possible. Many have made the observation that robotic systems are information systems and as such they have the ability to interface and integrate many of the technologies being developed for and currently used in the operating room.^9 One exciting possibil- ity is expanding the use of preoperative (computed tomogra- phy or magnetic resonance) and intraoperative video image fusion to better guide the surgeon in dissection and identify- ing pathology. These data may also be used to rehearse complex procedures before they are undertaken. The nature of robotic systems also makes the possibility of long-distance intraoperative consultation or guidance possible and it may
provide new opportunities for teaching and assessment of new surgeons through mentoring and simulation. Computer Motion, the makers of the Zeus robotic surgical system, is already marketing a device called SOCRATES that allows surgeons at remote sites to connect to an operating room and share video and audio, to use a “telestrator” to highlight anatomy, and to control the AESOP endoscopic camera. Technically, much remains to be done before robotic surgery’s full potential can be realized. Although these sys- tems have greatly improved dexterity, they have yet to de- velop the full potential in instrumentation or to incorporate the full range of sensory input. More standard mechanical tools and more energy directed tools need to be developed. Some authors also believe that robotic surgery can be ex- tended into the realm of advanced diagnostic testing with the development and use of ultrasonography, near infrared, and confocal microscopy equipment.^10 Much like the robots in popular culture, the future of robotics in surgery is limited only by imagination. Many future “advancements” are already being researched. Some laboratories, including the authors’ laboratory, are currently working on systems to relay touch sensation from robotic instruments back to the surgeon.^15 – 19,32^ Other laboratories are working on improving current methods and developing new devices for suture-less anastomoses.^33 –^35 When most people think about robotics, they think about automation. The pos- sibility of automating some tasks is both exciting and con- troversial. Future systems might include the ability for a surgeon to program the surgery and merely supervise as the robot performs most of the tasks. The possibilities for im- provement and advancement are only limited by imagination and cost.
CONCLUSION
Although still in its infancy, robotic surgery has already proven itself to be of great value, particularly in areas inac- cessible to conventional laparoscopic procedures. It remains
TABLE 3. Current Applications of Robotic Surgery
Orthopedic surgery Neurosurgery
Gynecologic surgery
Cardiothoracic surgery Urology
General surgery
Total hip arthroplasty: femur preparation
Complement image- guided-surgery
Tubal re-anastomosis Mammary artery harvest
Radical prostatectomy
Cholecystectomy
Total hip arthroplasty: acetabular cup placement
Radiosurgery Hysterectomies CABG Ureter repair Nissen fundoplication Knee surgery Ovary resection Mitral valve repair Nephrectomy Heller myotomy Spine surgery Gastric bypass Adrenalectomy Bowel resection Esophagectomy
Lanfranco et al Annals of Surgery • Volume 239, Number 1, January 2004
to be seen, however, if robotic systems will replace conven- tional laparoscopic instruments in less technically demanding procedures. In any case, robotic technology is set to revolu- tionize surgery by improving and expanding laparoscopic procedures, advancing surgical technology, and bringing sur- gery into the digital age. Furthermore, it has the potential to expand surgical treatment modalities beyond the limits of human ability. Whether or not the benefit of its usage over- comes the cost to implement it remains to be seen and much remains to be worked out. Although feasibility has largely been shown, more prospective randomized trials evaluating efficacy and safety must be undertaken. Further research must evaluate cost effectiveness or a true benefit over conventional therapy for robotic surgery to take full root. Table 3.
REFERENCES
- Satava RM. Surgical robotics: the early chronicles: a personal historical perspective. Surg Laparosc Endosc Percutan Tech. 2002;12:6 – 16.
- Felger JE, Nifong L. The evolution of and early experience with robot assisted mitral valve surgery. Surg Laparosc Endosc Percutan Tech. 2002;12:58 – 63.
- Marescaux J, Leroy J, Rubino F, et al. Transcontinental robot-assisted remote telesurgery: feasibility and potential applications. Ann Surg. 2002;235:487– 492.
- Cheah WK, Lee B, Lenzi JE, et al. Telesurgical laparoscopic cholecys- tectomy between two countries. Surg Endosc. 2000;14:1085.
- Jones SB, Jones DB. Surgical aspects and future developments in laparoscopy. Anesthiol Clin North Am. 2001;19:107–124.
- Kim VB, Chapman WH, Albrecht RJ, et al. Early experience with telemanipulative robot-assisted laparoscopic cholecystectomy using Da Vinci. Surg Laparosc Endosc Percutan Tech. 2002;12:34 – 40.
- Fuchs KH. Minimally invasive surgery. Endoscopy. 2002;34:154 – 159.
- Allendorf JD, Bessler M, Whelan RL, et al. Postoperative immune function varies inversely with the degree of surgical trauma in a murine model. Surg Endosc. 1997;11:427– 430.
- Satava RM, Bowersox JC, Mack M, et al. Robotic surgery: state of the art and future trends. Contemp Surg. 2001;57:489 – 499.
- Prasad SM, Ducko CT, Stephenson ER, et al. Prospective clinical trial of robotically assisted endoscopic coronary grafting with 1 year follow-up. Ann Surg. 2001;233:725–732.
- Kwoh YS, Hou J, Jonckheere EA, et al. A robot with improved absolute positioning accuracy for CT guided stereotactic brain surgery. IEEE Trans Biomed Eng. 1988;35:153–161.
- Davies B. A review of robotics in surgery. Proc Inst Mech Eng. 2000;214:129 – 140.
- Schurr MO, Buess GF, Neisius B, et al. Robotics and telemanipulation technologies for endoscopic surgery: a review of the ARTEMIS project. Advanced robotic telemanipulator for minimally invasive surgery. Surg Endosc. 2000;14:375–381.
- Dario P, Corrozza MC, Peitrabissa A. Development and in vitro testing of a miniature robotic system for computer-assisted colonoscopy. Com- put Aided Surg. 1999;4:1–14.
- Tholey G, Chanthasopeephan T, Hu T, et al. Measuring Grasping and Cutting Forces for Reality-Based Haptic Modeling. Computer Assisted
Radiology and Surgery, 17th International Congress and Exhibition, June 2003, London, UK.
- Hu T, Castellanos A, Tholey G, et al. Real-Time Haptic feedback Laparoscopic tool for use in Gastro-intestinal Surgery. Fifth Interna- tional Conference on Medical Image Computing and Computer Assisted Intervention (MICCAI), Tokyo, Japan, September 2002.
- Kennedy C, Hu T, Desai JP, et al. A Novel Approach to Robotic Cardiac Surgery using Haptics and Vision. Cardiovascular Engineering: An International Journal, 2002.
- Kennedy C, Hu T, Desai JP. Combining Haptic and Visual Servoing for Cardiothoracic Surgery. 2002 IEEE International Conference on Robot- ics and Automation , Volume: 2, 2002 Page(s): 2106 – 2111, Washington DC, May 2002.
- Kennedy CW, Desai JP. Force Feedback Using Vision. The 11th International Conference on Advanced Robotics, June 30 – July 3, 2003 University of Coimbra, Portugal.
- Cadierre GB, Himpens J. Feasibility of robotic laparoscopic surgery: 146 cases. World J Surg. 2001;25:1467–1477.
- Falcone T, Goldberg JM, Margossian H, et al. Robotic-assisted laparo- scopic microsurgical tubal anastomosis: human pilot study. Fertil Steril. 2000;73:1040 – 1042.
- Margossian H, Falcone T. Robotically assisted laparoscopic hysterec- tomy and adnexal surgery. J Laparoendosc Adv Surg Tech A. 2001;11: 161 – 165.
- Marescaux J, Smith MK, Folscher D, et al. Telerobotic laparoscopic cholecystectomy: initial clinical experience with 25 patients. Ann Surg. 2001;234:1–7.
- Abbou CC, Hoznek A, Saloman L, et al. Laparoscopic radical prosta- tectomy with a remote controlled robot. J Urol. 2001;165:1964 – 1966.
- Damiano RJJr, Tabaie HA, Mack MJ, et al. Initial multicenter clinical trial of robotically assisted coronary artery bypass grafting. Ann Thorac Surg. 2001;72:1263–1268.
- Mohr FW, Falk V, Diegeler A, et al. Computer-enhanced “robotic” cardiac surgery: experience in 148 patients. J Thorac Cardiovasc Surg. 2001;121:842– 853.
- Kappert U, Cichon R, Schneider J, et al. Technique of closed chest coronary artery surgery on the beating heart. Eur J Cardiothorac Surg 2001;20:765–769.
- Boehm DH, Reichenspurner H, Gulbins H, et al. Early experience with robotic technology for coronary artery surgery. Ann Thorac Surg. 1999;68:1542–1546.
- Cisowski M, Drzewiecki J, Drzewiecka-Gerber A, et al. Primary stent- ing versus MIDCAB: preliminary report-comparison of two methods of revascularization in single left anterior descending coronary artery stenosis. Ann Thorac Surg. 2002;74:S1334 – S1339.
- Hollands CM, Dixey LN. Technical assessment of porcine enteroenter- ostomy performed with Zeus robotic technology. J Pediatr Surg. 2001; 36:1231–1233.
- Hollands CM, Dixey LN. Robot-assisted eophagoesophagostomy. J Pe- diatr Surg. 2002;37:983–985.
- Morimoto AK, Foral RD, Kuhlman JL, et al. Force Sensor for laparo- scopic babcock. Stud Health Technol Inform. 1997;39:354 – 361.
- Tozzi P, Corno A, von Segesser L. Sutureless coronary anastomoses: revival of old concepts. Eur J Cardiothoracic Surg. 2002;22:565.
- Buijsrogge MP, Scheltes JS, Heikens M, et al. Sutureless coronary anastomosis with an anastomotic device and tissue adhesive in off-pump porcine coronary bypass grafting. 2002;123:788 – 794.
- Eckstein FS, Bonilla LF, Schaff H, et al. Two generations of the St. Jude Medical ATG coronary connector systems for coronary artery anasto- mosis in coronary artery bypass grafting. Ann Thorac Surg. 2002;74: S1363–S1367.
Annals of Surgery • Volume 239, Number 1, January 2004 Robotic Surgery
