Robotic Surgery for Prostate Cancer
Laparoscopic surgeries, in which a surgeon performs procedures through small incisions in the abdomen wall, have led to less invasive cancer surgeries with decreased pain and faster recovery times for patients. Because of the reduced size of the incisions, hospital stays are often shorter, with some patients even able to go home the same day.
During laparoscopic surgery, several slim, cylindrical ports, called trocars, are inserted into the patient's abdomen through small incisions. Long thin instruments, including a lighted camera called a laparoscope, are passed through the trocars and into the abdomen. These instruments include scissors, graspers, and other instruments modeled after the typical instruments used in traditional open procedures.
However, because the surgeon does not have direct contact with the patient's organs, and instead relies on a camera and monitor to view inside the body, there are certain limitations to laparoscopic surgery. For one, the surgeon is limited by the range of motion of the instruments. Unlike the human hand and wrist, the laparoscopic tools can only move in certain directions, limiting the types of actions that can be performed. In addition, because the surgeons are relying upon a two-dimensional screen displaying a mirror image of the instruments and the patient's anatomy, there is a loss of depth perception, and an impact on hand-eye coordination. A new alternative to laparoscopic surgery, which is increasing in popularity, is robot-assisted surgery.
Surgery robots, which have been around in one form or another since the mid-1980s, can help surgeons overcome many of the challenges presented by the open or laparoscopic surgical styles, or platforms. Currently, the most successful and widely used surgical robot is the da Vinci system, developed by Intuitive Surgical in Sunnyvale, CA. The da Vinci system is similar to the laparoscopic surgical platform in that long, thin instruments resembling traditional surgical instruments (Figure 1) are inserted into the patient through trocars, allowing for smaller incisions, less pain, shorter hospital stays, and faster healing times. However, the style of the instruments and the way in which they are controlled are very different.
As shown in Figure 2, the da Vinci system has three main parts: the console, where the surgeon sits to operate the robot; the patient side cart, which is positioned over the operating table and contains the arms that hold the instruments; and a third cart which provides a view of the surgery for the other doctors and nurses in the room. When the surgeon looks into the console, he sees a three-dimensional view of the patients internal organs and the surgical instruments, similar to what he would see when operating in an open platform. Unlike when operating in the open platform, however, the viewer can magnify the image, using a high-resolution endoscopic camera. The console gives the surgeon more control over his own field of vision than is normally available using a laparoscopic platform, and there is no mirroring. In addition, because of its ergonomic design, the surgeon is not required to stand in awkward positions, for long hours, while using the long instruments required for laparoscopic surgery.
The arms of the robot on the patient cart and the individual instruments are operated by hand controls on the surgeon's console (Figure 3) and foot pedals. Along with the magnification, the surgeon has the option of changing the scale of motion, so that the robot will reduce the amount of movement by a certain percentage. For example, if the surgeon moves his hand two inches, the robot can be set so that it will only move one inch. This is particularly useful for procedures needing extremely fine movements. The surgical robot also removes surgical tremor. In the open and laparoscopic platforms, if a surgeon's hands shake slightly, that tremor will affect the instruments. However, with the surgical robot, those extremely small movements are not translated into the instruments.
Perhaps the largest advantage of the robot is in the design of the instruments. Unlike most laparoscopic instruments which can only move in certain directions, the da Vinci's instruments are wristed. The surgeon can manipulate the instruments in multiple directions, giving the surgeon freedom similar to that of an open platform.
Students, as well as experienced surgeons who are new to the robotic platform, often learn on training machines that use models and inanimate objects to familiarize the trainee with the console and the use of the hand controls and foot pedals. Students can perform procedures, such as suturing and grasping, on foam circles and cones in order to become accustomed to the interface. This, of course, does not truly prepare the student for viewing anatomy through the console, so there are companies working to develop virtual reality models for the robot, to bridge the gap between operating on inanimate objects and operating on patients.
Robotic surgery and the da Vinci system are not without disadvantages. The largest disadvantage of robotic surgery is its cost. Currently, systems cost over $1 million and maintenance costs can be substantial. In addition, unlike operating in an open platform, the surgeon cannot feel the organs. When using the instruments to touch the organs, there is no tactile feedback, so surgeons must be extra vigilant about where each instrument is, in order to avoid damage to the organs. Finally, the da Vinci requires use of instruments that are manufactured only by Intuitive Surgical, Inc. If a procedure requires an instrument that is not currently available through the manufacturer, that part of the procedure must be completed by an assistant.
Surgical robots have been used in treating several cancers, including cancers of the lung, breast, gastrointestinal tract, kidneys, colon, rectum, bladder, prostate, testis, cervix, uterus, ovary, and tongue. The ability of this platform to blend benefits of both open and laparoscopic platforms has shown particular potential in the area of kidney cancer.