NEW YORK-Urologic surgeons at Beth Israel Medical Center are turning for help to a robot "assistant" that makes the difficult and time-consuming procedure of laparoscopic radical prostatectomy easier and more efficient.
NEW YORKUrologic surgeons at Beth Israel Medical Center are turning for help to a robot "assistant" that makes the difficult and time-consuming procedure of laparoscopic radical prostatectomy easier and more efficient.
Compared to conventional open surgery, laparoscopic radical prostatectomy is a minimally invasive procedure associated with a significant reduction in blood loss and postoperative pain. However, the procedure, introduced only 4 years ago, has a steep learning curve and is difficult to master.
The da Vinci Surgical System, developed by Intuitive Surgical, Inc., of Sunnyvale, California, promises to change all that. It combines a high-resolution, three-dimensional imaging system with miniaturized, robot-controlled instruments that can be moved precisely in any direction. The combination permits delicate operations to be performed with far greater dexterity and precision than would otherwise be attainable by conventional endoscopy.
At Beth Israel Medical Center, Caner Z. Dinlenc, MD, physician-in-charge of endourology, and Joseph R. Wagner, MD, physician-in-charge of urologic oncology, work as a team with two nurses and a surgical resident to perform laparo-scopic radical prostatectomies using the da Vinci system. They have completed 52 robot-aided operations to date. Beth Israel is one of only a dozen hospitals in the United States where the procedure is now routinely performed with robotic assistance.
Patients are typically discharged within 24 to 48 hours after the procedure, require little or no pain medication, and can return to their normal activities as early as 1 week after surgery, rather than the traditional 6 to 8 weeks. And because the operation is minimally invasive and precisely controlled, the risk of incontinence and impotencethe two major complications of conventional radical prostatectomyis low.
"Every study done thus far, both European and American, has shown that robotic surgery, at least in our early experience with the system, is as good as open surgery," Dr. Dinlenc told ONI. "Most surgeons doing the procedure feel confident that outcomes will continue to improve, ultimately surpassing open surgical results."
The da Vinci Surgical System is a robotics-assisted apparatus for performing endoscopic surgery under the direct control of a surgeon experienced in laparos-copy. The operating surgeon sits at a console several feet away from the operating table and manipulates the robot’s surgical instruments remotely (see Figure 1). Another surgeon sits beside the patient, maneuvering the placement of the robot’s arms and adjusting the camera and instruments as needed.
The robot has three arms attached to a freestanding cart that is rolled up to the patient’s side. One arm holds a binocular endoscope, while the other two arms hold the instruments. The endoscope and instruments are inserted through three ports, each less than 1 cm wide, in the patient’s lower abdomen. Two more small incisions are made for retracting organs and suctioning fluid.
At the business end of each of the robot’s instrument arms is a flexible mechanized "wrist" that the surgeon can bend and twist like a human wrist. Unlike conventional endoscopic instruments, which are capable of only four degrees of motion (up, down, right, and left) in a single plane, the da Vinci’s mechanical wrists replicate all six degrees of motion of the human wrist and can be rotated in a full circle, providing complete flexibility. "Not having this kind of flexibility in laparoscopic surgery," Dr. Wagner observed, "is akin to performing open surgery while wearing a cast on your wrist."
The instruments themselves are tiny replicas of full-sized surgical instruments, no bigger than a pencil, that can be attached and removed from the robot’s mechanical wrists in seconds (see Figure 2). Their small size permits precise, delicate movements that would be impossible to achieve with conventional endoscopic instruments.
One of the key benefits of robotic surgery, Dr. Wagner said, is that it eliminates the tremor associated with laparos-copy. As a result, the instruments held in the grasp of the robot’s arms remain steady at all times. By contrast, the long distance between the operating end of a conventional endoscopic instrument and its fulcrum, positioned at the insertion port several centimeters away, tends to amplify any tremor or sudden movements in the surgeon’s hand.
Tremor, Dr. Wagner explained, increases with the duration of the proceduretypically about 3 hours for an anatomic prostatectomyas fatigue in the shoulder and neck muscles develop from standing over the operating table. With the da Vinci system, the surgeon sits comfortably at a console fitted with head and arm supports, so that fatigue is largely averted even during a prolonged procedure. Repetitive tasks, such as suturing, can be precisely carried out under computer control (see Figure 3).
Feels More Natural
Because the robotic wrists smoothly and accurately mimic the motions of the surgeon’s own wrists in real time and right side up, performing the operation feels natural and is quickly learned, Dr. Wagner pointed out. "Try to imagine tying someone’s shoes while looking through a peephole with one eye and holding the laces with two long sticks," he said, "and you can visualize the difficulty of performing a conventional laparoscopic operation."
The da Vinci’s computer-enhanced optics and binocular vision can magnify the surgical field up to 10 times and present it in the same orientation as the naked eye would see it, giving the surgeon a three-dimensional view of the operating field. Conventional endoscopic cameras provide only a flat, two-dimensional image.
"The combination of small instrument size, maneuverability, and superior vision allows for more consistent preservation of the neurovascular structures involved with potency," Dr. Dinlenc commented. "The same holds true for muscular continence mechanisms."
Learning the Procedure
The Beth Israel team had 1 year of experience in laparoscopic radical prostatectomy before learning to use the robot. "The general experience among urologic surgeons, however, is different than ours, " Dr. Dinlenc said. "Most surgeons who call us for proctoring have not done a laparoscopic prostatectomy at all, and their first experience doing it will be with the da Vinci system. It appears to decrease some of the difficulty inherent in the operation, reducing the learning curve."
Dr. Wagner agreed. "Learning lapa-roscopy takes time and practice," he said, "to understand how to judge tension and distances from purely visual clues. With the da Vinci system, you can just jump right in from the start and get to work, tying knots or making a precise incision."
He acknowledged, however, that both he and his colleague are fortunate in having learned laparoscopy first. "If anything should go wrong during a robotic-assisted procedure," he said, "you can take over and finish the operation laparo-scopically without converting to open surgery." So far, that has not happened at Beth Israel.
If the da Vinci Surgical System has one drawback, it is the lack of tactile feedback from the operating instruments. "The lack of tactile sensation exists to a degree in standard laparoscopy but is quite common with robotic procedures," Dr. Dinlenc said. "Interestingly, surgeons already familiar with laparoscopic techniques develop skills in the visual interpretation of tension in tissues and sutures, which again underscores the importance of the superior optical experience."
Concurring with his colleague, Dr. Wagner remarked, "The loss in sensation is more than made up for by the gain in visual acuity provided by the robot’s magnified 3D optical system."
As to the future of robotic surgery, Dr. Dinlenc said, "Development is underway for even smaller and more maneuverable instruments in the near term. Also, a welcome advance will be the addition of a fourth arm to reduce the number of assistants at the bedside, and a graphic drawing tablet that interfaces with the visual system. This will aid mentoring trainee surgeons."
Dr. Wagner concluded: "The most important thing is that this new technology results in significantly less postoperative pain and faster recovery. It is now possible for patients who have received radical prostatectomies to be back at work, without limitations, within 1 to 2 weeks following the procedure."