Surgical robotics

TECHNOLOGY FOCUS

Surgical Robotics David S. Finley, MD, and Ninh T. Nguyen, MD Division of Gastrointestinal Surgery, University of California, Irvine Medical Center, Orange, California INTRODUCTION The earliest form of robotics originated in 1495 with Leonardo da Vinci and was popularized in 1921 in the play RUR by Karel Capek, and more recently by the science fiction writer, Isaac Asimov, who coined the term “robotics.” The dream of robotics is to create a machine that independently performs precise human tasks. Although industrial robots have been in widespread use for decades, surgical application has been more conservative. A selfpositioning stereotactic device, the Puma 560 (Staubli Automation Ltd, Duncan, SC), was first used by surgeons in 1985 for brain biopsy and later for transurethral prostatic resection.1 In 1991, the Food and Drug Administration (FDA) approved an orthopedic Robodoc (Integrated Surgical Systems Inc., Davis, California) model to assist in total hip replacement. In 1996, the U.S. Army developed the first remote surgical workstation that allowed an offsite surgeon to operate in a MASH unit by microwave telecommunication. All current systems are not truly robots because none are self-operating machines capable of performing autonomous tasks; nevertheless, the use of remotely operated machines by surgeons to perform complex surgical tasks is now a reality. One should remember that these machines only act at the direction of the operator (surgeon). As such they should more accurately be called “computer enhanced telemanipulator devices” or robotically assisted devices.

ROBOTIC SYSTEMS In 1994, the FDA approved Automated Endoscopic System for Optimal Positioning 3000 (AESOP, Computer Motion, Inc., Goleta, California) as the first robotically assisted surgical device. The AESOP employs a single mechanical arm with 6 degrees of freedom to position an endoscope. The AESOP allows the surgeon to position the endoscope through either voice-activated or manual controls. Speech recognition software allows “hands-off” endoscope movement via verbal commands such as “in,” “out,” “right,” and “left.” The AESOP has been used by surgeons in a variety of procedures (Tables 1-3).2-54 In a prospective study comparing AESOP to convenCorrespondence: Inquiries to Ninh T. Nguyen, MD, Department of Surgery, University of California, Irvine Medical Center, 101 City Drive, Building 55, Room 106, Orange, CA 92868; fax: (714) 456-6577; e-mail: [email protected]

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tional laparoscopy, AESOP significantly decreased inadvertent camera movement and improved visualization.55 A more advanced voice-activated robotically assisted device (Staubli Rx60) is currently in use by surgeons in Spain.56 Other novel robotically assisted systems are also in development. TISKA is a robotic positioning system that uses electromagnetic friction to maintain stable positioning (Karlsruhe Research Center, Germany). Endo-assist (Armstrong Healthcarte, United Kingdom) involves a helmet-mounted optical pointer that aims a camera, similar to the system that is used by the U.S. Army’s Apache attack helicopter pilots.

TELEPRESENCE A unique aspect of all robotic systems is the virtual or teleinterface between surgeon and patient. Unlike conventional open or laparoscopic procedures, the surgeon operates remotely from the surgical field. With most current robotic systems, the surgeon is in the same room; however, this is not obligatory. Some experimental systems termed “telepresence surgery” can be operated from thousands of miles away.57 In 1998, a telepresence system, termed “percutaneous access of the kidney” (PAKY) was successfully used by surgeons to obtain percutaneous access to the renal collecting system on a patient in Italy from Baltimore, Maryland. In 2001, a dramatic demonstration of telepresence potential occurred when a robotic-assisted laparoscopic cholecystectomy was successfully performed on a patient in France while the surgeon was in New York City using a Zeus system.58 Recent investigative systems are using the Internet or satellite telecommunication. Particularly attractive applications for telepresence surgery are the numerous hazardous or inaccessible sites where access to conventional surgery is either limited or impossible. Active development programs exist for application to deep sea and combat arenas, space, as well as to more conventional disasters or remote wilderness areas. This review will consider in detail only the 2 onsite robotic systems that are currently in widespread clinical application in the United States, the da Vinci (Intuitive Surgical, Sunnyvale, California) and the Zeus (Computer Motion Inc, Goleta, California). Several other devices, RoboDoc and NeuroMate, were designed for limited application in orthopedics and neurosurgery, respectively.

CURRENT SURGERY • © 2005 by the Association of Program Directors in Surgery Published by Elsevier Inc.

0149-7944/05/$30.00 doi:10.1016/j.cursur.2004.11.005

TABLE 1. Robotics in General Surgery, Gastrointestinal Surgery, and Colorectal Surgery First Author 2

Talamini Cadiere3 Beninca G4 Wykypiel H5 Chapman WH4 Gould6 Melvin7 Nguyen N8 Melvin7 Cadiere3 Talamini2 Beninca G4 Marescaux9 Kim10 Ruurda11 Nguyen N8 Delaney CP12 Talamini2 Merola13 Hildebrandt14 Talamini2 Nguyen N8 Cadiere3 Talamini2 Muhlmann G15 Nguyen N8 Cadiere16 Muhlmann G15 Delaney CP12 Munz17 Melvin WS18 Melvin WS19 Talamini2 Beninca G4 Nguyen N8 Talamini2 Chapman WH20 Talamini2 Nguyen N8 Talamini2 Talamini2 Melvin WS7 Melvin WS7 Cadiere3 Cadiere3 Cadiere3 Cadiere3 Cadiere3

Procedure Nissen fundoplication

Toupet fundoplication Cholecystectomy

Bowel resection

Roux-en-Y gastric bypass Gastroplasty Gastrojejunostomy Silicone adjustable gastric banding Implantable gastric stimulator Rectopexy Distal pancreatic resection Pancreaticojejunostomy Heller myotomy Splenectomy Duodenal polypectomy Gastric mass resection Lysis of adhesions Esophagectomy Pyloroplasty Inguinal hernia Arteriovenous fistula creation Appendectomy Lumbar sympathectomy Laryngeal exploration

CLINICAL ROBOTIC DEVICES The Zeus Robotic Surgical System was introduced in 1998. It employs a remote “master” workstation where the surgeon views a flat panel two-dimensional (2-D) or three-dimensional (3-D) display and maneuvers 2 hand-held manipulators to direct movement of 2 robotic arms that are attached to the operating table. The arms actuate trocar guided instruments in the operative field. The operator’s hand movements are digitized and translated into a preselected 2:1 to 10:1 robot motion in CURRENT SURGERY • Volume 62/Number 2 • March/April 2005

Robot

N

Subject

Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Zeus Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci AESOP AESOP Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Mona Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci

69 39 13 9 1 29 20 4 2 48 36 2 25 24 35 2 17 17 15 41 7 8 9 2 4 2 1 4 1 6 1 1 26 2 1 7 1 1 1 1 1 1 4 3 2 1 1 1

Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human

real time. A camera is mounted on a third arm that is either controlled by foot-pedal or by voice activation (AESOP). The surgeon can toggle between either 2-D or 3-D images. The Zeus Z2P model also incorporates passive eyewear stereovision—a shutter glass polarizes 2 pictures on the screen into a right polarized picture for the right eye and a left polarized picture for the left eye, which provides stereoscopic 3-D field viewing. A second bedside unit, the so-called “slave” unit, has versions with either 3 or 4 robotic arms attached to a mobile cart. In addition to the camera arm, 2 operative arms and a 263

TABLE 2. Robotics in Urology First Author 21

Rassweiler Ahlering22 Menon23 Wolfram M24 Tewari25 Yohannes P26 Menon27 Beecken W28 Menon29 Hubert30 Balaji31 Cho32 Schoor33 Partin34 Partin34 Guilloneau35 Talamini2 Horgan36 Guilloneau37 Partin34 Sung38 Sung38 Hoznek39 Partin34 Bentas40 Guilloneau B41 Sung42 Sung38 Gettman43 Hubert44 Young45 Beninca G4 Bentas46 Brunaud47 Talamini2 Sung38 Sung39 Cadiere3 Partin34 Su48 Partin34 Partin34 Kaouk49

Procedure Prostatectomy

Cystectomy ⫹ neobladder Cystoprostatectomy Ileal conduit Extravesical ureteral reimplantation Vas deferens reconstruction Ureterolysis Pelvic lymph node dissection Nephrectomy

Recipient Renal transplant Pyeloplasty

Adrenalectomy

Varicocele ligation Percutaneous access to the kidney Orchiopexy Nephropexy Sural nerve grafting

fourth optional arm for retraction exist. The controls allow for grasping and for 4 degrees of freedom: in/out, left/right, up/ down, and rotation. A second-generation Microwrist technology allows for an additional degree of freedom. The da Vinci system, also introduced in 1998, uses a surgeon-operated console located outside the sterile field. The da Vinci’s Insite Vision System affords true stereoscopic 3-D vision of the surgical field by means of a 12-mm endoscope with 2 independent optical channels attached to an articulating arm. Magnification of up to 20⫻ is available. Unlike Zeus, the da Vinci encases the surgeon’s face in a console to view the 2 “eyepiece” cathode ray tube monitors from each of the digital camera channels, which gives the surgeon the sense of being totally immersed in the endoscopic field with no external visual 264

Robot

N

Subject

Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Zeus Da Vinci AESOP AESOP Zeus Da Vinci Da Vinci Zeus AESOP Da Vinci Zeus Da Vinci AESOP Da Vinci Zeus Zeus Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Zeus Da Vinci AESOP PAKY-RCM AESOP AESOP Da Vinci

6 100 250 118 30 2 3 1 14 1 2 1 8 1 1 10 15 12 1 4 6 5 1 3 11 10 6 16 9 14 6 9 4 14 6 5 5 1 2 23 1 1 3

Human Human Human Human Human Human Human Human Human Human Human Animal Rat Human Human Human Human Human Human Human Pig Pig Human Human Human Pigs Pigs Pigs Human Pigs Human Human Human Human Human Pig Pig Human Human Human Human Human Human

cues as distractions. Another difference between the two systems is the da Vinci’s EndoWrist has 6 degrees of freedom and adjustable grip strength. The instrument tips can articulate up and down as well as left and right. Rotation of the master controls clockwise results in “intuitive” clockwise rotation of the instrument. The surgeon’s master console contains foot controls that include a clutch that allows the surgeon to disengage the master controls from actual movement of the instruments. This feature facilitates frequent repositioning. Additional foot controls include the camera motions, zoom and focus pedals, as well as coagulation. Intuitive Surgical has also developed an upgrade to the current system, a fourth robotic arm, which the surgeon may use as a “self-assistant” without affecting the movements of the operative arms. CURRENT SURGERY • Volume 62/Number 2 • March/April 2005

TABLE 3. Robotics in Gynecology First Author 50

McDougall EM Di Marco51 Cadiere52 Goldberg53 Cadiere3 Margossian54 Cadiere3 Margossian54 Cadiere3 Partin34

Procedure Sacrocolpopexy Tubal reanastomosis Hysterectomy Neosalpingostomy Adnexectomy Endometriosis cure Burch bladder suspension

The net effect of both systems is an agile mechanical wrist that far exceeds that of conventional laparoscopy. Both systems have instantaneous translation of hand-eye coordination and 3-D depth perception during suturing and tissue handling. Both have a comfortable, ergonomic sit-down workstation that minimizes surgeon fatigue. Both provide high visual magnification and software that scales down surgeon movement and filters out hand tremors (ie, ⬎6 Hz). The robot is a major advance in the control of many procedures because of precise, reproducible, comfortable, ambidextrous tissue dissection and microsuturing far superior to conventional laparoscopy. Despite these advantages, a significant drawback to both systems is the absence of a haptic (sense of touch) feedback. As the surgeon cannot sense the amount of force being applied, he/she must rely on visual cues. Although current haptic sensing technology does exist, it allows for detection of only about 0.6 N of force, roughly equivalent to a 4-mm deflection of soft tissue. This degree of sensitivity may be insufficient for robotically assisted microvascular procedures. It is also expensive. A third system, RoboDoc, has been designed for and limited to orthopedic applications. RoboDoc is an active computercontrolled device that once programmed can execute a limited procedure independently of the operator. It was created to enhance bone prosthetic implant sizing, positioning, and placement. It consists of a preoperative planning computer (OrthoDoc, Integrated Surgical Systems, Davis, California) that uses 3-D computed tomography image data coupled to a 5-axis arm that holds a milling device. Based on inputted data, Robodoc can create a plan and mill the bone with specialized drill bits. Several other orthopedic robotically assisted systems have been developed but none systematically tested: CASPAR (Computer-Assisted Surgical Planning and Robotics; Ortomaquet Inc., Rastatt, Germany) is similar to Robodoc. It can create a bone tunnel for reconstruction of the cruciate ligament and prepare bony surfaces for total knee and hip arthroplasty. NeuroMate (Integrated Surgical Systems Inc., Davis, California) is an image-guided robotic system used by surgeons for stereotactic neurosurgical procedures. It consists of a console and single robotic arm with 5 degrees of freedom. The NeuroMate console, like OrthoDoc, enables processing of preoperative computed tomography (CT) or magnetic resonance images CURRENT SURGERY • Volume 62/Number 2 • March/April 2005

Robot

N

Subject

Da Vinci Da Vinci Da Vinci Zeus Da Vinci Zeus Da Vinci Zeus Da Vinci AESOP

2 5 28 10 2 10 1 5 1 2

Human Human Human Human Human Pigs Human Pigs Human Human

(MRI) to create a 3-D map of the brain; instruments are then guided along the optimum path based on this information.

ROBOTICS IN ORTHOPEDIC SURGERY Although other orthopedic robotically assisted systems exist, RoboDoc is the most widely used system by surgeons for robotic bone milling. In a prospective randomized study specifically of RoboDoc, 141 total hip replacements were performed59; 61 cases were performed with robotic assistance, and 80 cases were performed manually. Limb length equality and varus-valgus orientation of the stems were better with the robotically assisted procedures compared with the control group. The authors noted that orthopedic surgery is particularly well suited for robotic assistance because the exact location of bone anatomy can be digitally fed into the robot’s computer, which makes preoperative planning relatively easy.59 In addition, operator fatigue caused by prolonged drilling and forceful manipulation is eliminated. However, in their study, Robodoc had major drawbacks: 26 robotically assisted patients required conversion to manual implantation because of a robotic system failure. There were 11 (18%) robotically assisted patients with dislocations versus only 3 (4%) patients in the manual group. There was also an unacceptably high rate of sciatic nerve injury (7%) attributed to clamping by the mechanical arm. Surprisingly, the robotically assisted reaming time of the femoral shaft was slower compared with the manual, which added 30 minutes to the procedure. No deaths occurred. The authors concluded that although RoboDoc had no notable learning curve and was useful in preoperative planning, it had too many complications to justify widespread use. In another study, patients who underwent Robodoc versus conventional total hip arthroplasty were assessed postoperatively by 3-D gait analysis. No difference was found in hip abduction between groups, which suggests that patient’s outcome with Robodoc was at least as good as the conventional method.60 CASPAR, an alternative orthopedic robotically assisted device, has been used by surgeons for assistance in total hip and knee replacement as well as for repair of the anterior cruciate ligament (ACL).61,62 Siebert et al used CASPAR in a series of 70 robotically assisted total knee replacements61; they successfully completed 69 of the 70 cases and found that tibio-femoral 265

TABLE 4. Robotics in Cardiothoracic Surgery First Author 63

Damiano Mohr64 Kappert65 Boehm66 Boyd67 Talamini2 Detter68 Isgro69 Mohr63 Nifong70 Argenziano71 Reichenspurner72 Argenziano71 Morgan73 Melfi74 Bacchetta75 Morgan73 Morgan73 Killewich76 Malhotra77

Procedure CABG

IMA takedown

Mitral valve repair Atrial septal defect repair Patent foramen ovale repair Thoracoscopic lobectomy Pericardial cyst resection Mediastinal mass resection Phrenic nerve pacemaker implantation Aortic reconstruction

alignment was within 1 degree of the preoperative plan. The authors concluded that CASPAR performed significantly better than either manual or existing computer-assisted techniques.

COMPARISON OF ROBOTICALLY ASSISTED SYSTEMS Both Zeus and da Vinci are being used in an ever-widening array of surgical procedures (Tables 1-6).63-85 Of the approximate 15 million surgeries performed annually in the United States, an estimated 25% are performed laparoscopically. At present, virtually any laparoscopic procedure is amenable to robotically assisted surgery. Only 1 head-to-head trial comparing Zeus with da Vinci has been reported, however; it was limited to a small number of cases of nephrectomy, adrenalectomy, and pyeloplasty.38 The da Vinci system was found to be easier to use and was associated with a shorter learning

Robot

N

Subject

Zeus Da Vinci Da Vinci Zeus Zeus Da Vinci Zeus Zeus Da Vinci Da Vinci Da Vinci Zeus Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci

18 131 37 25 104 14 12 56 17 38 12 7 5 1 5 1 2 6 1 5

Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Human Lamb

curve and operative times. Although numerous feasibility studies as well as several small trials comparing laparoscopy versus robotically assisted surgery have been reported, a paucity of outcome data remains in the form of randomized clinical trials that demonstrate the greater efficacy and efficiency of robotically assisted surgery. Currently, the da Vinci is the most widely used platform worldwide. With the recent merger of Intuitive Surgical and Computer Motion Inc. into a single conglomerate company in 2003, a more powerful second-generation robot will undoubtedly benefit from the unique qualities of each system.

ROBOTICS IN GENERAL SURGERY AND GASTROINTESTINAL SURGERY The field of general surgery and gastrointestinal surgery, in particular, has seen the broadest expansion in the use of

TABLE 5. Robotics in Pediatric Surgery First Author 78

Hollands

Lorincz79 Gutt86 Gutt80 Lorincz79 Le Bret81 Aaronson82 Gutt80 Gutt80 Shanberg83 Shanberg83 266

Procedure Enteroenterostomy Hepaticojejunostomy Esophagoesophagostomy Portoentorostomy Nissen fundoplication Thal fundoplication Heller myotomy Patent ductus arteriosus closure Myelomeningocele Hysterectomy Cholecystectomy Pyeloplasty Vesico-vaginal fistula repair

Robot Zeus

Zeus Da Vinci Da Vinci Zeus Zeus Da Vinci Da Vinci Da Vinci Da Vinci Da Vinci

N

Subject

5 5 5 5 5 3 8 1 28 6 1 2 7 2

Piglet Piglet Piglet Piglet Human Human Human Human Human Sheep fetus Human Human Human Human

CURRENT SURGERY • Volume 62/Number 2 • March/April 2005

TABLE 6. Robotics in Otolaryngology and Neurosurgery First Author Haus84 Haus84 Haus84 Federspil85

Procedure

Robot

N

Subject

Parotidectomy Thymectomy Neck dissection Skull milling for cochlear implantation

Da Vinci Da Vinci Da Vinci

1 1 6

Pig Pig Pig

RX-130

2

Human

robotically assisted surgery (Table 1). Virtually all general abdominal and pelvic procedures have been successfully performed by robotically assisted surgery including esophagectomy, Heller myotomy, Nissen fundoplication, rectopexy, and major bowel resection. In addition, routine cholecystectomy and appendectomy, as well as more complex pancreaticojejunostomy, have all been performed with robotically assisted surgery. Robotically assisted surgery can occasionally accomplish a procedure that otherwise would have been difficult via laparoscopy. Recently, Jacobsen et al86 reported a collaborative review of robotically assisted bariatric surgery for morbid obesity. Of 11 centers using the da Vinci system, 10 responded on a total of 107 robotically assisted procedures that varied from Roux-en-Y gastric bypass, to gastric banding, to biliary pancreatic diversion. All centers found that robotically assisted surgery is a safe modality. In the super obese patient (BMI ⬎ 60 kg/m2), robotically assisted surgery had unique advantages. Conventional laparoscopy through a very thick abdominal wall is often difficult because of the necessary increased torque; robotically assisted surgery easily overcomes this. In addition, a robotically assisted hand-sewn gastrojejunostomy was thought to be superior to stapling techniques because a smaller pouch can be created. The oropharyngeal trauma caused by the placement of the stapler anvil transorally is eliminated. None of the centers had anastomotic leaks. With experience, the robotic setup time decreased from 35 to 7 minutes. For the 1 center performing only gastric banding (n ⫽ 32), the mean operative time was 100 minutes and hospital length of stay was 1 day, a 0.86-day reduction from conventional laparoscopy. Complications were minimal and mostly related to improper port placement. One patient had a postoperative pulmonary embolism. No long term outcome data were available. Despite their enthusiasm for robotically assisted surgery, the authors cautioned that a prospective randomized trial is needed. Melvin et al87 conducted a prospective trial of computerenhanced “robotic” fundoplication compared with standard laparoscopy in a series of 40 patients. He found longer operative times and similar outcomes in the robotically assisted versus laparoscopic group and concluded that robotically assisted antireflux surgery offered minimal advantage over conventional laparoscopy. Cadiere et al88 drew similar conclusions from a comparable study. CURRENT SURGERY • Volume 62/Number 2 • March/April 2005

ROBOTICS IN UROLOGY Prostate surgery also has aspects that make robotically assisted surgery attractive, including the depth of the pelvis, which is relatively inaccessible, and the difficulty of visualizing small structures in a limited operative field. Since November 2000, several hundred cases of robot-assisted prostatectomy have been performed by Menon et al.89 They reported a large prospective but nonrandomized study evaluating the outcome of robotically assisted versus radical retropubic prostatectomy. Blood loss was significantly lower in the robot group (153 ml versus 910 ml) with fewer transfusions (11% vs 67%). Operative time was similar between groups (160 min vs 163 min). Marked improvements were found in total postoperative catheterization time (7 d vs 15 d), mean time to return of continence (44 d vs 160 d), and mean time to return of erection (180 d vs 440 d). Standard complications were also diminished in the robotic group (5% vs 20%). Hospital length of stay was greatly shortened, with 93% of the robotically assisted group discharged within 24 hours versus none in the conventional prostatectomy group. More recently, this group has reported a series of 17 radical cystoprostatectomies using the da Vinci system.23 The robot was used by the surgeons for all operative steps except for creation of the orthotopic neobladder. Pyeloplasty and ureteropelvic junction obstruction procedures have been successfully performed with both the Zeus and the da Vinci systems. Gettman et al43 performed a successful da Vinci assisted Anderson-Hynes pyeloplasty in a series of 9 patients with an operative time of 139 minutes. This same group subsequently reported a case-controlled study of robotically assisted versus laparoscopic pyeloplasty with a similar decrease in operative and suturing time.90 For the more challenging Anderson-Hynes pyeloplasty, the mean operative and suturing times showed an even greater degree of improvement (140 min vs 235 min, 70 min vs 120 min) using the da Vinci system compared with conventional laparoscopy. Robotically assisted systems have also been successfully used by surgeons for nephrectomy and adrenalectomy.37,91-93 In pigs, Gill et al91 compared robotically assisted nephrectomy and adrenalectomy. Although both groups required longer total operative time compared with laparoscopy (52 min vs 38 min and 51 vs 32 min, respectively), blood loss and quality of surgical dissection were comparable between groups. This series was then followed with a report of the first human robotically assisted adrenalectomy.92 In 2001, Guillonneau et al37 used the Zeus system for robotically assisted human nephrectomy with an operative time of 200 minutes and blood loss of less than 200 ml. Others have used the da Vinci device to perform transplant donor nephrectomy.93 Again, there was a significant advantage with the robot versus conventional laparoscopy in mean operative time (166 min vs 110 min), warm ischemia time, and blood loss. All allografts functioned at implantation without an acute rejection episode. The authors concluded that the robot improved identification and allowed more precise dissection of both the ureter and the renal vessels. Finally, the 267

first robotically assisted recipient of a renal transplant has now been reported.94 Isolated case reports using robotically assisted orchiopexy and nephropexy are listed in Table 2. An interesting study by Ahlering et al22 addressed the question of how easily an experienced open surgeon with no laparoscopic experience can learn robotic surgery. After a 1-day training course on the da Vinci and 2 subsequent cadaveric laboratories, the author performed 45 successful robotically assisted prostatectomies. The learning curve has been estimated at 10 cases. All usual physical parameters, pad use, continence and potency, were excellent. There were no bladder contractures, and blood loss was remarkably low (134 ml). Ahlering et al concluded that the da Vinci robot was relatively easy to master and greatly facilitated learning laparoscopy, in general, and that more specifically, it resulted in less blood loss and morbidity than did open prostatectomy.

ROBOTICS IN CARDIOTHORACIC SURGERY Robotically assisted surgery is being used by surgeons for an expanding number of cardiothoracic procedures (Table 4).63-77,95 Robotically assisted coronary artery bypass grafting (CABG) was performed in 19 patients with the Zeus robot.95 Postoperatively, 17 of the 19 grafts (89%) were functional. The other 2 had poor flow and required manual revision. This technique was further advanced by Boyd et al,97 who performed robotically assisted CABG on 6 patients without bypass or cardioplegia. Five of the 6 grafts were patent. A similar robotically assisted CABG without bypass using the da Vinci was performed on 29 patients.96 Postoperative patency was 100%; however, one patient was converted intraoperatively to manual reconstruction. Since then, others have also performed robotically assisted tricuspid leaflet resections, chordae tendinae revision, and septal defect closures.98,99 Before the advent of robotics, advances in laparoscopic cardiothoracic surgery had been hampered by an inability to perform microsuturing with conventional laparoscopic instruments. Robotically assisted surgery overcomes this problem because robotic field magnification, tremor filtration, motion scaling software, and the increased dexterity of robotic instruments easily allow for precise suturing below the limits of visibility.

ROBOTIC TRAINING By far the major limitation for more rapid development and acceptance of robotic surgery is the limited number of training institutions. In a recent survey of over 400 general surgery residents, 57% reported a high interest in robotic surgery. However, only 20% indicated they had access to a robotic training program.100 Training in robot surgery is less daunting than commonly believed. In fact, in one study, the increased dexterity of the da Vinci system actually accelerated all laparoscopic 268

training as compared with laparoscopy.101 Novice laparoscopic surgeons performed 3 of 4 drills faster robotically as compared with expert laparoscopic surgeons using laparoscopy. The authors suggested that robotic surgery “evens the playing field” between surgeons of varying skill levels. But not all authors agree with the apparent robotic learning curve advantage. In a study by Prasad et al102, the performance on standardized laparoscopic tasks was compared between naïve and experienced surgeons using laparoscopy compared with the Zeus platform; they found that with both groups of surgeons, task completion times were shorter with laparoscopy than with robotics and no difference in task precision could be found between the two groups. However, they did find that the learning curve with robotic surgery was faster than with laparoscopy. Advanced software simulations will facilitate future robotic training. Such simulation affords objective surgical assessment, in a cheap, consistent, innocuous environment. Simulators will have a “telestrator” capability, which allows a remote proctor to use a touch screen to highlight areas of interest on the trainee’s monitor. Robotic startup capital costs are high ($1-1.3 million per da Vinci robot, $100,000/yr maintenance, approximately $2000/ instrument), and any savings offsets derived from robotic surgery have yet to be systematically measured. Nevertheless, robotically assisted surgery already has demonstrated direct cost savings from lessened blood loss and morbidity, which results in decreased length of hospital stay. Additional indirect savings resulting from improved operative field visibility, enhanced surgical dexterity, and standardization of microsuturing await measurement. With global availability and decreased cost, robotically assisted surgery may ultimately expand the surgical pool that can tackle many complex procedures currently restricted to only those that have mastered advanced techniques.

FUTURE DEVELOPMENTS In just a little over two decades, robotically assisted surgery has gone from a science fiction notion, to advanced prototypes and animal trials, to successful use in humans. Although virtually all human trials have received enthusiastic reviews across a huge range of applications, they have been small in scale and few randomized trials exist. Nevertheless, robotically assisted surgery now enjoys the same exciting promise to revolutionize surgery as did laparoscopy 20 years ago. Robotically assisted surgery offers certain advantages in virtually all fields of surgery. Its current major drawback is a lack of tactile (haptic) feedback. Although current robotically assisted surgery controls can convey feedback of vector force, they still do not allow operator appreciation of the sensations of pressure, tension, heat, and vibration. Even this problem now seems to be a temporary engineering hurdle. Newer robotic models now being designed incorporate software and instrumentation that allows the surgeon to have sophisticated real-time, continuous sensory feedback. One should not lose sight of the rapid changes of robotics, no CURRENT SURGERY • Volume 62/Number 2 • March/April 2005

matter what its current problems are. The next robotic generation should have precise scaling of motion (100:1) allowing for inconceivable microsurgery to a 10-100-micron accuracy. Such definition is 20 times that of the unassisted human hand. Future robotic systems will be computer integrated with preoperative digitized magnetic resonance imaging and computed tomography images allowing for unique preoperative planning for optimal port placement, surgical approach, and precise identification of critical anatomic landmarks. In addition, robotics should be able to integrate color Doppler, fluoroscopy, and spectroscopy to provide the operator with real-time assistance. Thus, the surgeon’s view screen will provide an intraoperative image overlay (so-called “augmented reality”) superimposed on a simultaneous unobstructed view of the patient, which allows the surgeon to “see” underlying structures, blood flow, and pathologic tissues. Advanced cameras with high-performance optics will afford a wide-angle panoramic view with brighter, more evenly distributed lighting that allows the surgeon full control of imagery. Future robotic models promise to be smaller, more compact, and offer additional degrees of freedom. They may have rapidly deployable ceiling mounted arms instead of the current cumbersome time-consuming bedside deployments. Smaller 5-mm instrumentation with modular tips providing greater than 90 degrees of tip motion will have a higher force/stiffness ratio and a smoother rolling action. Nextgeneration instruments will also offer energy-directed therapy such as laser, radio-frequency, high-intensity focused ultrasound, and thermal ablation.85 In the more distant future, engineers are even dreaming up true robots where the surgeon need only “tag” the ends of a structure and press a button, and the robot automatically sutures and ties the 2 structures together with speed and precision. According to Moore’s law,52 in which data density doubles every 18 months, perhaps the future is not as distant as we might think.

ACKNOWLEDGMENT Thank you to Miguel Canales, MD, and Scott Finger for insight into the future of robotics.

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