Telesurgery Remote Monitoring and Assistance During Laparoscopy

Takeshi Inagaki, Sam B. Bhayani, and Louis R. Kavoussi

Summary. Laparoscopic surgery is the most commonly practiced and accepted form of minimally invasive surgery. Laparoscopic surgery in urology has, in many instances, become the standard of care. However, laparoscopy is associated with a steep learning curve because of its complexity and difficulty.This learning curve causes long operative times and potentially increases operative complications. Interestingly, to date there are no formal credentialing guidelines. Telesurgery has become feasible with the advent of recent Internet and robotic technology. This new technology has applicability within urology, as it enables an expert laparoscopic surgeon to mentor an inexperienced surgeon from a remote location. In this article, we review the background to current telesurgical research and describe experiences, with emphasis on the current status of this technology within urology. Telesurgery is feasible and may play a major role within urology. Although the utility of this technology is apparent, especially within minimally invasive approaches, barriers such as technical limitations and legal implications may hinder its progress and eventual acceptance. Urologists standing at the beginning of the twenty-first century should be cognizant of the eventual implementation of this technology.

Keywords. Laparoscopy, Telesurgery, Telementoring, Robot Introduction

During the past 20 years, minimally invasive surgery has influenced the techniques used in every specialty of surgery. Laparoscopic surgery has been the most visible aspect of minimally invasive surgery. Laparoscopy not only has supplanted conventional procedures, but also has stimulated surgeons to reevaluate conventional approaches with regard to perioperative parameters such as post-

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operative pain, cosmesis, recovery, and length of hospital stay. As in general surgery and gynecology, laparoscopic surgery has a great role in the realm of urologic surgery. The initial emphasis was on ablative procedures [1-3]. Ratner and his coworkers reported the first laparoscopic donor nephrectomy in 1995. This has become a standard operation [4]. As urologists became more skilled, the most challenging aspect of laparoscopy became reconstructive surgery. With the development of suturing and intracorporeal knot tying, many reconstructive procedures were successfully completed laparoscopically [5]. Additionally, laparoscopic surgery began to expand into such technically advanced surgeries as radical cystectomy [6,7] and radical prostatectomy [8].

Although laparoscopy has moved into the mainstream of urologic surgery, one major drawback has emerged. The ability of surgeons to perform laparo-scopic surgery improves significantly as they gain experience with the procedure. This is the so-called learning curve, and the drawback is that learning curve for most surgeons is still steep because of complexity and technical difficulties, in comparison with the learning process in open surgery. Furthermore, complications may be more common during a surgeon's initial experience with laparoscopy [9].

Telemedicine is a rapidly developing field that takes advantage of the information highway to provide physicians and patients with global access to health care [10]. In laparoscopic surgery, all members of the surgical staff, including the primary surgeon, assistant surgeon, and operation room staff, watch the same laparoscopic images. Therefore, transferring of laparoscopic images readily influences education and assistance in laparoscopic surgery. In that context, laparoscopic surgery is the most appropriate surgery that adopts telesurgical technology. Telesurgery, a subcategory of telemedicine, would enable a laparo-scopic surgeon to educate a less experienced surgeon from a remote place [11]. In this article, we review the background of current telesurgical research and describe clinical experiences.

Background

Definitions of Terms

Teleproctoring: Teleproctoring is the monitoring and evaluation of surgical trainees from a distance. In its most simple form, teleproctoring can provide oneway communication from the local operating room to the remote specialist workstation. The use of modern telecommunications in proctoring for the purpose of granting of hospital privileges, specialty board credentialing, and training has the potential to make a significant impact. Its enables the expanded use of real-time skill assessment and technique surveillance [12].

Teleconsultation: Teleconsultation involves transmission of still or video images for review by a remote specialist, who then communicate his or her opinions to the local surgeon [13].

Telementoring: Telementoring involves the remote real-time guidance of a treatment or a surgical procedure where the local doctor has no or limited experience [13]. This interaction requires two-way communication by video and audio, which must occur simultaneously between the local and the remote site. Furthermore, it is mandatory that the time lag of this communication be as short as possible.

Robotic surgery: The Robot Institute of the USA defines a robot as "a programmable multifunctional manipulator designed to move materials, parts, tools, or specialized devices through variable programmed motions for the performance of a variety of tasks" [14]. The first robots introduced into clinical surgical procedures were controlled directly by the surgeon at the operating room table [15,16]. More recently, robotic surgery has involved active control of surgical instruments, such as graspers, electrocautery, scissors, etc., by a surgeon located at a remote site [17-20].

Telepresence surgery: The success of telerobotic surgery has spurred interest in telepresence surgery. Telepresence surgery is defined as an operation controlled by a remote surgeon via telerobotic technology [21,22].

Other technical terms used in telesurgery, especially in data transmission, are listed briefly in Table 1.

Types of Communication Links

Telesurgery is dependent on reliable data transmission between the primary operating room and the remote site. Conventional telephone and modem, Ethernet, ISDN, ADSL, and ATM are currently used for transmission of information (Table 2) [23,24]. In telesurgery, time delay in the transmission of surgical information is a major problem. Currently, ISDN is the most frequently used mode of transmission, and three or four ISDN lines are generally used for telesurgical transmission [25]. Janetschek et al. reported that the time delay for telementoring between Innsbruck in Austria and Baltimore in the United States using three ISDN lines was 1 second, which did not present a problem for transcontinental telementoring [26]. However, three ISDN lines provide only 384kbps, and the sharpness of the transmitted image is limited. ATM provides high-speed packet switching data services, and a mean time delay of 155 ms over a transoceanic distance was reported [21]. Technical surveys of network architectures for teleradiology suggest that ATM is the most reliable high-speed switching network available for this application [27].

Currently Available Robotic Systems

Telesurgery is usually carried out by using various surgical robots.

Table 1. Definition of technical terms used in telesurgery

Term

Definition

ATM Asynchronous transfer mode: a high-speed and high-quality terrestrial fiberoptic network

Bandwidth The amount of data that can be transmitted over a line or channel in a fixed amount of time. A higher bandwidth results in higher information-carrying capacity

Broadband A high-speed, high-capacity transmission channel

Cable modem Digital modem that supports Internet access using the coaxial cable provided by cable television providers. Bandwidth is approximately 2 Mbps

DICOM Digital imaging and communication in medicine

DSL Digital subscriber lines: sophisticated modulation schemes that pack large amounts of data onto copper telephone wires. Now available to consumers, these systems provide high-bandwidth connections to the Internet (as high as 32 Mbps)

Duplex Transmission of data between parties simultaneously in both directions

Encryption Translation of data into code for security purposes. To read encrypted data, the recipient must have access to a key that enables decryption

Force-feedback Transmission of force information from a remote instrument back to the operator in an attempt to simulate tactile sensation

Frame rate A measure of how information is used to store and display motion video.

Each frame is a still image, and the frame rate is described as frames per second (fps)

ISDN Integrated services digital network: an international standard for transmitting data over digital telephone lines. Supports transfer rates in increments of 64 Kbps

Time lag Time delay for an instruction to be encoded on a local machine, propagated over a transmission line to a remote machine, decoded, and executed

Table 2. Types of communication links and their data transfer speed

Network Typical speeds (kbps)

Local area network Ethernet Fast ethernet Wide area networking Telephone and modem ISDN

Broadband ISDN Broadband ISDN ADSL ATM

10,000 100,000

56 64-128 384 631 512-2,000 25,000-155,000

Kbps, kilobits per second; ISDN, integrated services digital network; ADSL, asynchronous digital subscriber line;ATM, asynchronous transfer mode

Fig. 1. AESOP (automated endoscopic system for optimal positioning) camera holder enables a single surgeon to perform a laparoscopic procedure

AESOP

AESOP (automated endoscopic system for optimal positioning) was initially approved by the US Food and Drug Administration (FDA) for clinical use in 1994. AESOP's arm was modified to hold a laparoscope. Initially AESOP was attached to the operating table and controlled manually or remotely with a foot switch or hand control [27, 28]. More recently AESOP may be controlled by voice activation (Fig. 1) [29].

PAKY

PAKY (percutaneous access to the kidney) is a radiolucent, sterilizable needle driver located at the terminal end of the robot arm. The needle driver utilizes an axial-loaded rotational-to-translational friction transmission principle to grasp, stabilize, and advance an 18-gauge access needle into the kidney percuta-neously. Needle insertion is driven by a variable-speed, battery-powered DC motor [30].

Da Vinci

The first telerobotic surgery system was developed by Green and colleagues at the Stanford Research Institute (SRI International, California, USA) in 1992 [31]. This system was then developed commercially as the MOMA telesurgery system (Intuitive Surgical, California, USA), and was later improved and renamed the da Vinci telesurgery system 17]. The da Vinci system now uses

EndoWrist technology, giving the arm seven degrees of freedom in its articulated movement, and has two cameras to allow a three-dimensional view to be presented through a specialized binocular arrangement [18,19].

ZEUS

The ZEUS system (Computer Motion, California, USA) is similar in design to the da Vinci system. It has robotic arms on the patient side that attach directly to the operating table, and the surgical site is viewed on the screen by the theater staff. The ZEUS system uses a voice-controlled AESOP robotic arm (Computer Motion) to hold a camera and has a range of laparoscopic instruments that attach to the other two arms [18, 20].

Progress to Date

In the realm of pathology and radiology, teleconsultation for pathological diagnosis and radiological diagnosis has been refined in the last decade. One of the first reports of real-time teleconsultation was published by Kyser and Drlicek in 1992 [32]. They transferred histopathological images of intraoperative sections by use of normal telephone lines between two departments of pathology. It was reported that the transfer of an image lasted for 1.4 to 2min, and the expert discussion was finished 3 min after the transfer of the last image. Using the Internet as a telecommunication pathway for static images is a low-cost, widely available option [33, 34]. Recently, dynamic telepathology has used remote-controlled microscope systems with high-throughput online image-transport channels [35]. This method has the advantage of entire slide access and prevent errors from preselected microscopical frames. On the other hand, internet technology has enabled computed tomographic (CT) images and magnetic resonance images (MRI) to be downloaded from a centralized server and displayed at a remote hospital or a radiologist's home [36-38]. Tachakra et al. reported that teleradiological consultation is effective to prevent patients from being transferred unnecessarily [39].

In general surgery, Chinnock reported that since virtual reality systems have become digitally based, they have become capable of being put on line for tele-training, consulting, and even surgery [40]. In addition, surgical teleproctoring during laparoscopic surgery was reported by Hiatt and his coworkers [41]. In 1997, Rosser telementored laparoscopic colectomies performed by inexperienced surgeons [42]. This area has been of particular interest to military and National Aeronautics and Space Administration (NASA) surgeons who face the challenges of emergency procedures in remote locations, aboard ships at sea, or in space [43-45]. Cubano et al. reported five laparoscopic hernia repairs performed successfully abroad the USS Abraham Lincoln Aircraft Carrier Battle group under remote telementoring guidance [43]. In Japan, the telecommunica tion center was established at Osaka and has been operational since 1997 using six ISDN channels. The network, composed of five remote hospitals, aimed to teleeducate young surgeons in constituent hospitals, and it was applied not only to teleeducation in routine endoscopic surgery, but also to telementoring in advanced operations [46].

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