Robot-assisted laparoscopy

INTRODUCTION — A surgical robot is a computer-controlled device that can be programmed to aid the positioning and manipulation of surgical instruments. Surgical robotics is typically used in laparoscopy rather than open surgical approaches. Since the 1980s, surgical robots have been developed to address the limitations of laparoscopy, including two-dimensional visualization, incomplete articulation of instruments, and ergonomic limitations. The goal of robot-assisted laparoscopic surgery is to help surgeons improve patient care by converting procedures that would have otherwise been performed by laparotomy into minimally invasive procedures. Robot-assisted laparoscopic surgery has all of the advantages of minimally invasive surgery, including less postoperative pain, smaller and possibly more cosmetically appealing incisions, shorter hospital stay, shorter recovery time, and faster return to work.

In its initial phase, robot-assisted procedures were performed almost exclusively by surgeons with advanced laparoscopic skills. However, since the da Vinci robot (one type of robot-assisted surgical platform) was approved by the US Food and Drug Administration for use in gynecologic surgery in 2005, there has been rapid adoption of robot-assisted laparoscopic procedures in gynecology by surgeons of all skill levels. Based on data published in 2008 [1], there were more than 645 da Vinci systems in use worldwide, and since then, there continued to be an exponential rise in the use of these surgical systems to 3477 units by late 2014 [2] and over 5000 units installed in 2018 [3]. Barriers to the adoption of robotics in surgery include the expense, training requirements for physicians and nurses, and lack of high quality data. Similar to conventional laparoscopy, robot-assisted laparoscopy has been widely adopted prior to emergence of data supporting efficacy and safety.

The role of robot-assisted laparoscopy in gynecologic surgery will be reviewed here. Related topics are discussed separately:

●General principles of conventional laparoscopic surgery (see "Abdominal access techniques used in laparoscopic surgery")

●Single port laparoscopy (see "Abdominal access techniques used in laparoscopic surgery", section on 'Single-incision laparoscopic surgery')

TERMINOLOGY — Surgical robots can serve several functions, including [4]:

●Passive – Robotic movements are set preoperatively or act to guide the surgeon to a surgical target. Types of passive robots are:

•Autonomous – Robot performs a sequence of movements which are programmed preoperatively (eg, Probot).

•Supervisory – Robot serves as a navigational aid or a precise positioning system (usually using preoperative imaging studies) to direct the surgeon to a lesion or other surgical target (eg, Minerva). Intraoperative ultrasound may be used to guide a surgeon to a tumor within an organ such as the liver or kidney. As an example, gynecologic oncologists use colorimetric or fluorometric sentinel lymph node mapping during robot-assisted surgery for endometrial cancer [5].

●Active – Surgeon directs the robot intraoperatively to move the surgical instruments. Terms used to describe active robots include:

•Immersive – Surgeons are using the robot as a tool, but are deeply engaged in the operative field as if they were actually right at the operative field. This is made possible by high quality imaging, magnification of the three-dimensional (3D) laparoscope, and use of a direct line of sight to position the instruments that the surgeon's hands are controlling.

•Haptics – The lack of haptics (ie, tactile feedback) is a limitation of robot-assisted surgery. The surgeon cannot actually feel the resistance of the tissue as the instrument meets or manipulates the tissue, but accommodates for this by using visual cues and knowledge of anatomy and surgical planes based upon previous surgical experience and study of anatomy.

•Teleoperated or telerobotic – The robot is manipulated by input devices under the surgeon's control remote from the operating table.

•Telepresence surgery – Teleoperated/telerobotic surgery in which the surgeon is located outside of the operating room (eg, in another city or country).

•Telementoring – Transmission of audio and video information from a robot-assisted set-up to a remote site, thereby allowing an expert surgeon to guide a novice through a procedure.

•Telestration – For use in telementoring, a surgical mentor can draw on the operating surgeon's video display.

•Dual-console system – An innovation in surgical training introduced in 2009 involving two consoles with the option to swap control of instruments and increase robot-assisted surgical exposure from one surgeon to two per procedure (picture 1) [6].

HISTORY OF SURGICAL ROBOTICS — Surgical robotics were first used in 1985 in neurosurgery; applications soon followed in urology and orthopedics. Major milestones in the development of robotics are listed below [4,7]:

●First robot-assisted surgery (1985) – The PUMA 560 was used to orient a needle for a brain biopsy under computerized tomography guidance [4].

●Robot-assisted surgery extended to urology (1988, Probot), orthopedics (1992, Robodoc), and gynecology (1999, Zeus) [4,8].

●Robot-assisted laparoscopic camera holder introduced (1994). The Automated Endoscopic System for Optimal Positioning (AESOP) was the first robot-assisted device approved by the US Food and Drug Administration for use in intraabdominal surgery; AESOP would later be included in an integrated robotic surgical system, however, this system is no longer available (2001, Zeus) [7]. A surgically controlled robot called the ViKY was introduced and previously used as a voice-activated control of the laparoscope for single-port procedures [9]. The same technology has been used to position the uterus during minimally invasive hysterectomy.

●Robotic telepresence technology became commercially available (the surgeon is at a remote site, yet has the feel of being in the operating room) (2000, da Vinci). The system was developed by the Stanford Research Institute and National Aeronautics and Space Administration [7]. The prototype was originally designed for use by the military to provide immediate operative care on the battle field from a remote surgical station.

ROBOT-ASSISTED VERSUS OTHER SURGICAL APPROACHES

Discussion of conventional and robot-assisted laparosocpy — While conventional laparoscopy has led to notable improvements in surgery, challenges include limitations in optics and instrumentation, need for advanced surgical training to perform complex procedures (specifically in laparoscopic suturing and knot-tying, ureterolysis, and dissection of and within the retroperitoneal space), and poor surgeon ergonomics remain challenges [4,10]. Robot-assisted laparoscopy has features which overcome the difficulties of conventional laparoscopy and may also introduce new surgical options (eg, remotely performed surgery). However, cost is higher and operative time (including time for robot set-up and disassembly) is typically longer, particularly when a surgeon is learning the technique. Surgeon fatigue is minimized by use of a console at which the surgeon may sit comfortably.

●Comparison with laparotomy – Conventional and robot-assisted laparoscopy share similar advantages over laparotomy, including decreased morbidity, rapid recovery, and improved aesthetics of incisions. However, both of these minimally invasive routes have introduced trocar injuries, insufflation related problems, and trocar-site abdominal wall hematomas when compared with laparotomy. As with conventional laparoscopy, there is an increased risk of bladder and ureteral injury with robot-assisted laparoscopy compared to open surgery.

Delayed thermal injuries are also increased compared with laparotomy because of increased use of electrosurgical instruments in conventional and robot-assisted laparoscopy procedures. Increased incidence of vaginal cuff dehiscence has also been reported with robot-assisted and conventional laparoscopic hysterectomy (LH) [11,12]. This has been attributed to the use of monopolar energy to perform the colpotomy incision and risk of lateral spread of thermal energy and subsequent inadequate closure due to inadequate purchase of tissue during suturing of the vaginal cuff. Many surgeons advocate barbed suture to facilitate vaginal cuff closure, while others favor closing the vagina from below as in routine vaginal hysterectomy. (See "Vaginal cuff dehiscence after total hysterectomy".)

●Unique complications of robot-assisted surgery – Unique complications that may occur with robot-assisted laparoscopic surgery include mechanical breakdown of the robot equipment, use of excessive pressure on various tissues due to lack of tactile feedback, erroneous activation of a control, errant movement or positioning of a robotic arm, or loss of a needle outside of direct vision while the console surgeon is zooming in on various structures. Newer system designs have reduced or eliminated some of these complications.

●Data specific to gynecologic surgery for benign indications – For benign gynecologic disease, there is no high-quality evidence that robot-assisted laparoscopy is superior to laparotomy or conventional laparoscopy [13]. As such, the American Association of Gynecologic Laparoscopists (AAGL) states that robot-assisted laparoscopy should not replace conventional laparoscopic or vaginal procedures for benign gynecologic disease [14].

Data examples include:

•General surgical outcomes – In a meta-analysis of 22 studies (mainly retrospective) that compared robot-assisted surgery with other approaches, robot-assisted surgery was associated with less blood loss and shorter length of hospital stay [15]. When compared with conventional laparoscopy, the only significant difference for robot-assisted surgery was a decrease in blood loss and fewer conversions to open surgery for endometrial cancer staging.

•Myomectomy – A retrospective cohort of 134 patients with eight-year mean follow-up reported no difference in long-term bleeding or fertility outcomes among robot-assisted, laparoscopic, or abdominal myomectomy procedures [16]. A subsequent review comparing laparoscopic and robotic-assisted myomectomy showed that the robotic approach may be favored for cases of higher complexity and multiple fibroids [17].

•Endometriosis – A trial comparing conventional laparoscopy with robot-assisted surgery in 73 patients with endometriosis reported similar operative times and perioperative outcomes (blood loss, complications, and conversions) [13,18].

Use of robot-assisted laparoscopy for specific procedures is discussed separately. (See "Oophorectomy and ovarian cystectomy", section on 'Use of robotic or single-port laparoscopy' and "Surgical myotomy for achalasia", section on 'Robotic surgery' and "Radical cystectomy" and "Hysterectomy: Laparoscopic".)

Advantages of robotic surgery — The major advantages of robot-assisted over conventional laparoscopy are [19,20]:

●Superior visualization – Conventional laparoscopy provides two-dimensional (2D) imaging of the operative field. A robotic system affords a 3D vision while allowing rapid zooming and panning of the camera. The newer systems have enhanced visualization with automatic white balancing, calibration, and focus.

●Mechanical improvements – A fulcrum effect is created when rigid conventional instruments pass through the incision, thereby leading to inversion of movement from the surgeon's hand to the working end of the instrument [20]. When an instrument is introduced into a trocar, the abdominal wall is the fulcrum. When a surgeon's hand moves in one direction, the instrument moves in the opposite direction. If a patient is obese, there is more torque placed on an instrument and the rigid smaller caliber instruments, such as laparoscopes, may fracture. Robotic instruments are less likely to break, thus, many surgeons prefer robot-assisted laparoscopy in patients with obesity. This is because all robotic instruments are 8 mm wide and attached to the robotic arms, which in turn are attached to the robotic cannulas (trocars). The force that the abdominal wall places on each instrument is sustained by the trocar and mechanical robotic arm. The robotic laparoscope is 8 or 11 mm in diameter and is also introduced through a trocar, which is docked to the robotic scope arm. In contrast, conventional laparoscopy is performed with 3 or 5 mm instruments that are introduced through smaller trocars.

Also, similar to the human arm and hand, robotic instruments have seven degrees of freedom, which allow wrist-like or "EndoWrist" movement that facilitates suturing, especially for trainees. Conventional rigid laparoscopic instruments only have four degrees of freedom. While flexible laparoscopic instruments (eg, Autonomy Laparo-Angle) can also move with seven degrees of freedom, their use requires additional training because the movements are not intuitive [21]. For comparison, all electrosurgical robotic instruments are available and wristed except the harmonic scalpel, which is not wristed.

●Stabilization of instruments within the surgical field – In conventional laparoscopy, small movements by the surgeon are amplified (including errors or hand tremor). Robot-assisted surgery minimizes surgeon tremor.

●Improved ergonomics for the operating surgeon – Having the surgeon be seated while using telerobotic systems provides significant ergonomic benefits, particularly when compared with conventional laparoscopy and open abdominal surgery [22,23]. While being seated appears to improve ergonomics for all surgeons [23], not having to stand for long periods may be of particular benefit for surgeons who are pregnant, those with orthopedic or mobility limitations, or those who are operating on patients with an elevated body mass index.

Limitations of robotic surgery — The limitations of robotic technology include [19]:

●Additional surgical training.

●Increased costs and operating room time.

●Bulkiness of the devices.

●Instrumentation cost and limited uses for instrumentation. For example, each DaVinci instrument is limited to 10 uses, and cost per instrument ranges from USD $220 to $320, excluding single-use ultrasonic energy instruments and advanced vessel, which range from USD $545 to $595.

●Lack of haptics (tactile feedback).

●Risk of mechanical failure.

●The older da Vinci systems are not designed for abdominal surgery involving more than two quadrants (the device needs to be redocked and repositioned to operate in the quadrants it is not facing). The upgraded da Vinci Si and "X" systems have 50 percent more range of motion in the robotic arms but may still require redocking. The newer, more costly da Vinci Xi models do not need to be redocked to operate in opposite quadrants because the arms, which rotate as a group, are connected to an overhead boom allowing unobstructed access to the patient.

Robotic surgical systems are designed with features intended to minimize the potential effects of mechanical failures on patients [19]. Such features include system redundancy, so-called ''graceful'' performance degradation or failure, fault tolerance, just-in-time maintenance, and system alerting. In simplified terms, there are several mechanical checks and balances built into current robotic surgical systems so that the risk of mechanical failure is minimized.

ROBOTIC DEVICES

Types of systems — Available robotic surgery systems include: the robotic camera holder (AESOP), an immersive telerobotic surgical system (eg, da Vinci), and open remote-control stations (eg, Senhance (picture 2) or Versius). The Versius system is available in the United Kingdom and is undergoing FDA trials in the United States.

●Robotic camera holders

•AESOP – The robotic camera holder (AESOP) provides a steady platform for the camera, eliminates the need for a human camera holder [24], frees the surgeon to control other instruments, and makes it possible to operate without an assistant and/or to use an additional port site. AESOP was initially introduced with surgeon-operated foot switch or hand control [25,26] and was later modified to respond to voice commands with a 23-word vocabulary [27]. The device facilitated single-port laparoscopy for some surgeons. However, the AESOP surgical system is no longer commonly used given the wider adoption of integrated robotic platforms.

•ViKY – The ViKY system offers vision control of the laparoscope and motorized, voice-controlled assistance that eliminates the need for a surgical assistant to position the camera or other endoscopic tools [9]. Use of this system has been applied to uterine manipulation as a motorized uterus positioner (ViKY UP) [28].

●Immersive telerobotic surgical system – For these systems, surgery is performed by a surgeon seated at a console remote from the operative field (picture 1).

Surgical components — Robot-assisted surgical systems are typically comprised of the surgeon's console, a surgical cart that holds three to four surgical arms (picture 3), and an equipment cart that holds the monitors and other components (eg, light sources, energy devices) [29,30]. An example of an immersive system is pictured here (picture 1). Other variations include open-console and single-port systems [9,31].

OPERATIVE PROCEDURE — Initially, the patient is positioned and prepped similarly to conventional laparoscopy.

Laparoscopic access — Prior to docking the robot, it may be appropriate to use a conventional laparoscope to explore the entire abdomen if the surgeon prefers a 5 mm visual port entry. In some circumstances, conventional laparoscopy can be used to free adhesions, or mobilize bowel, to allow the needed ports for the robot. Simply because a robotic procedure is possible does not mean that conventional laparoscopy cannot be used. For gynecologic procedures, the following incisions are typically made, although care is taken to both limit the number of incisions and types of instruments (figure 1 and picture 4):

●12 mm midline upper abdominal for the Si and Xi robots and 8 mm for the Xi – Laparoscope port; placement is at least 20 cm superior to the pubic symphysis and at least 8 to 10 cm superior to the uterine fundus.

●8 mm lateral lower abdominal – Robotic accessory ports; two ports placed bilaterally, inferior and 8 to 12 cm lateral to the laparoscope port (ie, midclavicular line, lateral to the rectus muscle, making a 15- to 30-degree angle); if the fourth robotic arm (the third operating arm) is used, then this port is placed 8 to 12 cm lateral (at the same level or cephalad) to the previously placed robotic port (either on the right or left side, depending on the surgeon's needs; this distance between ports is needed to avoid collision of the robotic arms). For newer surgical systems, the port placement is closer and equidistant (8 cm between instruments) because the laser targeting placement allows ease in positioning of the arms, which rotate as a unit (picture 4).

●8 to 10 mm lateral upper abdominal – Conventional accessory port (ie, for suction/irrigation, introduction of sutures, removal of specimens); placed on the left or right side of the patient, superior and medial to the ipsilateral robotic accessory port based on surgeon preference. 8 mm ports accommodate sutures with small half-circle (SH or CT-2) needles without requiring fascial closure; hence, the patient is at a lower risk of developing musculofascial pain from wound closure of laparoscopic sites.

The robotic arms are attached to these ports and, after this point, the operating table is no longer moved when using the older models of the surgical robot. During the surgery, the assistants stand at the patient's side and change the instruments.

The equipment tower supporting the robotic arms can be docked centrally (ie, placed between the patient's legs (figure 2)) or side-docked (figure 3), depending on the system. Side-dock location provides unobstructed access to the lower abdominal quadrant and pelvic structures (eg, vagina, perineum). Side docking can be performed with the robot tower positioned 45 degrees to the patient's left or right leg stirrup or in parallel to the patient's bed. For gynecologic surgery, side docking has been reported to improve access to the vagina and perineum and reduce assistant fatigue and the potential for injury due to a collision with the robotic arms. In our practice, we perform parallel side docking of the robot tower in the majority of procedures due to improved efficiency and ease and greater access to the vagina and perineum [32]. The da Vinci Xi system has an overhead arm architecture that can provide the surgeon with anatomical access from virtually any position, simplifying multiquadrant surgeries. Smaller, thinner arms coupled with longer instrument shafts also permit a greater range of motion and more flexibility. (See 'Vaginal access for gynecologic surgery' below.)

Surgeons are seated at a console, view the operative field via a binocular device, and place their hands in the "masters" hand controls, which translate the movements of their hands into an electric signal which travels via a cord to the surgical cart and activates the robotic arms. These "masters" can be modified to adjust the ratio of motion of the surgeon's hand to that of the robotic arms (motion scaling). As an example, a 3:1 ratio allows for every 3 cm of movement by the surgeon, only 1 cm movement by the robotic arm. Another "masters" modification adjusts the speed at which the instruments move. The hand controls also filter hand tremors, resulting in error reduction and more efficient suturing and dissection.

Surgeons supinate and pronate their hands while stepping on the camera foot pedal to focus the picture. There are buttons on the hand controls to clutch the arms and thus the instruments in order to improve instrument precision. The dual console system improves a surgeon's ability to teach a trainee because both surgeons are able to sit at a console simultaneously, visualize the operative field in 3D, and swap control of various instruments (picture 1).

Foot pedals control the camera, energy devices, and "masters." The pedals act to toggle each of these functions (ie, if you press on the camera foot pedal, the movement of the hand controls moves the camera in the same direction; if you press down on another foot pedal [corresponding to a robotic arm], you activate the energy source associated with the attached instrument).

The robotic arms, located on the surgical cart, are attached to surgical instruments through a robotic instrument adapter. An 11 mm telescope is connected to the central robotic arm and contains two 5 mm telescopes, producing 3D vision (picture 5). Newer systems employ optics that can provide high definition (HD) vision in three dimensions in a smaller 8 mm telescope with autofocus capability. Each instrument passes through a reusable 8 mm system-specific port [4]. Some robotic ports have valves, which allow insufflation through the robotic trocar.

Disadvantages of the da Vinci system are similar to those of other robotic systems, including a lack of tactile feedback and the bulkiness of equipment (restricts placement of accessory ports in small patients and movement of operating room staff), limited instrumentation, and difficulty changing the patient's position. TransEnterix's Senhance system is less bulky as it has individual units that are brought into the surgical table (picture 2). The control unit is not immersive and special glasses are used to obtain a 3D image. Cost remains a major drawback for all robotic systems and instrumentation, which in the current economic environment cannot be underestimated.

Successive upgrades of the robotic system have allowed each version to have more and more intuitive and efficient instrument swapping, energy control, camera manipulation, and better surgeon ergonomics [29].

Vaginal access for gynecologic surgery — With use of side or overhead docking of the surgical robot, vaginal access is similar to access for conventional laparoscopy with an assistant seated between the patient's legs.

There are several available uterine and vaginal manipulators. Placement of the uterine manipulator is performed during set up of laparoscopic equipment. Some of these can be attached to a device that is placed between the patient's legs, thus replacing the role of a vaginal surgical assistant. As an example, RUMI instruments are attached to the Uterine Positioning System. With this system, the device may be held in place by one or two stitches in the cervix. Other manipulators, such as VCare and Valchev, do not require stay sutures. Choice of uterine manipulator is a matter of surgeon preference.

TELEROBOTICS IN EDUCATION AND SIMULATION — Surgical simulation, telementoring, and telepresence surgery are potential novel benefits of robot-assisted technology. Physical distance between an expert surgeon in a telementoring or telepresence set-up requires safeguards in case of mechanical failure or surgical complication (eg, latency of signal from mentoring to operating surgeon, failure of internet lines), although these have not yet been established.

Robot workstations can transmit video and audio information to a surgical simulator [19,33]. Robotic simulation could allow rehearsal of procedures with the potential for reduction in complication rates and learning curves, and even for the development of new technical approaches. In addition to providing input integration of imaging registered with an interventional robotic platform, robots can capture data regarding how a surgeon performs specific tasks. In one study, robotic surgery training based upon simulation was equally effective as that based upon live animal models [34]. However, simulation-based training in robotic surgery is still under investigation and not in wide use because of cost and access.

Telementoring provides the ability for an experienced physician at a remote site to be able to mentor a less experienced surgeon in training or in real time [35-38]. As an example, in one report, transmission of audio and 3D video with telestration between a group of surgeons in the United States and Italy allowed telementoring of urologic procedures [35]. However, this function was provided only by the Zeus system, which is no longer available. When two consoles are available with the da Vinci Si system, the surgeon is able to mentor another surgeon by maintaining control of various instruments and swapping instruments. There are no published data yet to support routine use of a dual console system compared with an attending surgeon standing at bedside to assist a training surgeon.

Telepresence surgery is another innovation which may be possible with robotic technology. The largest series (n = 21) is from Canada, where a group of general hospital surgeons performed surgery at a distance of 400 km using the Zeus system [39]. There were no conversions to laparotomy, however, a skilled surgeon was present at the remote site to manage complications and complete the surgery conventionally, if necessary. Information was transmitted using commercially available internet lines with a signal latency of 135 to 140 milliseconds, which was easily perceived by the surgeons. The US Food and Drug Administration requires that all operations using a telerobotic system are performed in the same room as the patient.

The speed of information transmission is a key element in telepresence surgery. Surgeons are able to complete tasks with a delay in operating room to console signal transmission of up to 500 milliseconds [40].

ISSUES IN IMPLEMENTING A ROBOTIC SURGERY PROGRAM — Major obstacles to the clinical use of robots are cost, training of physicians and nursing teams, and lack of outcome data [19]. There is no doubt that robotic technology is fulfilling its promise to allow both generalists and subspecialists to gain competence in complex laparoscopic procedures. This is particularly the case for surgeons who have not had training or experience in complex conventional laparoscopic procedures that involve laparoscopic suturing, knot-tying, ureterolysis, retroperitoneal dissection, and minimally invasive hysterectomy for the enlarged uterus.

Is robotic surgery included in surgical training programs? — Training and credentialing standards have not yet been established for robotic surgeons [19,21,41]. Robotic training programs have become part of many surgical residency and fellowship programs, but such training is not standardized or required.

●Robotic Training Network – The Robotic Training Network (RTN) is a surgical training curriculum created with financial support from the device industry. Training guidelines or requirements have not been standardized for robot-assisted laparoscopy education in residencies. While some US residents and fellows will be trained as part of this curriculum, it is at the discretion of the residency or fellowship director whether the trainee is competent or not. Although there is a reliable and validated instrument developed by the RTN that can be used to assess technical skills in performing robotic surgery (robotic objective structured assessment of technical skills [ROSATS]), it has not been widely adopted [42].

●Industry-sponsored training – Intuitive surgical provides two paths to certification: A one-day laboratory at a training facility or a resident/fellowship equivalency. The company makes no official recommendations regarding number of cases, proctoring, etc, as those are up to the individual hospital's credentialing requirements. Additionally, there are five robotic training modules that must be completed online as part of the training.

●Determining appropriateness of robot-assisted surgical privileges – There are no standardized criteria in hospitals across the United States to discern whether a surgeon coming out of training or from another institution should receive robotic privileges. The time has come in the United States that newly introduced procedures in a resident's or fellow's training may be performed using robot-assisted or conventional laparoscopy rather than laparotomy.

How should a surgeon in practice learn robotic surgical skills? — Surgeons should set up three robotic cases prior to scheduled training in an animal laboratory at various robotic-training centers so that they can immediately implement the training and reinforce what they learned in the animal or cadaver laboratory. Trainees are also required to pass five online training modules in order to obtain a certificate that documents their training experience. The number of mentored patient procedures leading to independent practice varies from institution to institution and will likely be individualized based on surgical experience and technical ability. Additionally, many institutions are imposing a certain volume of cases so that surgeons maintain a competent skill level, although individual differences in acquiring skills make an arbitrary number of completed cases illogical. Additionally, performance of one type of pelvic surgery does not necessarily mean another type of pelvic procedure can also be performed safely. Credentialing requirements vary among institutions, and many institutions are in the process or have recently established criteria for credentialing surgeons to perform procedures on robotic platforms. Finally, in the United States, there is no current residency curriculum requirement established by the Residency Review Committee for robot-assisted surgery.

Surgical learning curves depend on two aspects of surgical volume: total number of procedures performed and the time interval between procedures [43,44]. Experience from urologic surgery suggests that acquiring robotic skills is possible with intensive training (eg, a five-day course) [45-47], but further study is needed for other surgical specialties. Proficiency in a new procedure includes both the procedure itself and the ability to manage complications [43]. In addition, safe surgical practice also depends upon continued surgical volume after training, just as for open procedures. Additionally, most experts agree that a surgeon should be competent in performing a procedure via laparotomy before learning a robotic approach. However, if a procedure is performed almost exclusively via a minimally invasive, rather than open, approach, then the trainees may learn to perform it with robot-assisted or conventional laparoscopy as the standard approach.

In studies of robot-assisted laparoscopic hysterectomy (LH), 15 to 70 cases were required to achieve an operating time of approximately two hours [11,48,49]. Similarly, a case series of 113 robot-assisted procedures performed by two surgeons with advanced laparoscopy skills found that set-up time, operative time, and blood loss improved until approximately 50 cases had been performed, and then stabilized [50].

Are surgical robots cost-effective? — Robot-assisted surgery is expensive.

●Examples of purchase costs – Robot-assisted laparoscopy systems cost approximately USD $2 to 3 million [51]. The da Vinci system cost ranges between USD $1.8 and 2.3 million, depending on the system, and each instrument attached to the robotic arm costs between USD $2200 and $3500. These arms must be replaced after 10 uses. For example, in our practice, for a robot-assisted sacral colpopexy, we use a pair of scissors, electrosurgical and bowel grasping forceps, and two needle drivers, which each cost USD $220 to $350 per case, for a total procedure cost of USD $1270. However, this cost could be decreased if we used a grasper as a needle driver; nevertheless, this may decrease suturing efficiency and increase total operating room time, and thus cost, as a result.

●Cost-effectiveness analysis – Results of cost-effectiveness analyses vary by whether single-procedure or overall robotic costs are included and by a hospital's surgical volume [52]. Costs incurred by robotic surgery include capital acquisition, limited use instruments, team training expenses, equipment maintenance, equipment repair, and operating room set-up time. As noted above, robot-assisted cases cost approximately $2000 more per case than the same procedure performed by conventional laparoscopy. (See 'Robot-assisted versus other surgical approaches' above.).

In the era of health care reform, this elevated cost may be the greatest detriment to continued implementation of robotic surgery, especially since industry competition has not yet emerged to instigate more affordable pricing. More prospective studies are required to analyze overall costs (direct and indirect) of robot-assisted procedures to health care systems. Further investigation is warranted.

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Laparoscopic and robotic surgery".)

SUMMARY AND RECOMMENDATIONS

●What is a surgical robot? – A surgical robot is a computer-controlled device that can be programmed to aid the positioning and manipulation of surgical instruments. The goal of robotic gynecologic surgery is to use a minimally invasive approach to perform procedures which are generally performed by laparotomy or are too complex for conventional laparoscopy or surgeons who are novices in laparoscopic surgery. (See 'Introduction' above.)

•Advantages – Advantages of robotic over conventional laparoscopy include three-dimensional (3D) imaging, mechanical improvement (eg, instruments with seven degrees of freedom), stabilization of instruments within the surgical field, and improved ergonomics. The major advantage to the patient is a potentially shorter hospital stay, and more rapid postoperative recovery and return to full function. (See 'Advantages of robotic surgery' above.)

•Limitations – The limitations of robotic technology include high costs and increased operating room time, lack of tactile feedback, large size of the devices, and risk of mechanical failure. (See 'Limitations of robotic surgery' above.)

●Types of surgical systems – Several robotic systems are available: the robotic camera holder, an immersive telerobotic surgical system, and an open remote-control system. (See 'Robotic devices' above.)

●Novel uses of telerobotics – Surgical simulation, telementoring (guidance given to the surgeon by another surgeon who is not in the operating room), and telepresence surgery (surgery performed via a robot by a surgeon who is not in the operating room) are potential novel benefits of robotic technology. (See 'Telerobotics in education and simulation' above.)

●Obstacles to adoption – Some obstacles to the clinical use of robots are cost, physician and nursing team training, and need for more outcome data. Further evaluation and implementation will determine the role of robot-assisted laparoscopy. (See 'Issues in implementing a robotic surgery program' above.)