Robotic-assisted surgery is poised to become a standard technique for many head and neck surgical procedures, according to experts. Robotics has already been approved for prostate surgery, heart surgery, gastric bypass, and hysterectomy. If preliminary results in early studies of some head and neck surgical procedures are borne out, transoral robotic surgery (TORS) should also be approved by the FDA.
Background
In 2005, Bert W. O’Malley, Jr., MD, Gabriel Tucker Professor and Chairman, and Gregory S. Weinstein, MD, Professor and Vice Chairman and Director of the Division of Head and Neck Surgery at the University of Pennsylvania in Philadelphia, led the research team performing 10 robotic-assisted base-of-tongue resection experiments in cadavers and animals using the da Vinci Surgical Robot (Intuitive Surgical, Inc., Sunnyvale, CA). The purpose of these studies was to learn how to position the da Vinci arms in a patient’s mouth, Dr. Weinstein said. He described robotic-assisted procedures as follows: the surgeon sits at a console where the surgical field is displayed in high-quality, three-dimensional video, and small joysticks are used to control the robotic arms. The patient is positioned remotely, approximately 10 feet away.
Using joysticks to control the robotic arms takes away tremor, renders the surgeon ambidextrous, and utilizes miniaturized motions to make surgical incisions. The tip of the instrument goes into the patient’s mouth, and it’s as if you are standing inside the mouth. You get a broad, three-dimensional view of the surgical field, Dr. Weinstein explained.
Many surgical procedures that are experimental for robotics are currently done with laryngoscopic surgery along with a laser beam delivered through the scope using long instruments. A broad view of the surgical field is not possible with larygoscopy techniques, Dr. Weinstein noted.
Types of Procedures
Several types of head and neck surgical procedures are amenable to robotic-assisted surgery. Robotics can be used to resect benign and malignant tumors of the oral cavity, including the pharynx and larynx, tonsil, tongue base, supraglottis, glottis, pyriform sinus, and the parapharyngeal space.
Transoral robotic surgery is presently ideal for cancers or benign tumors of the oropharynx and supraglottis, and this technique is also useful for tumors in the pyriform sinus, but access is more difficult. It should be used for tumors not lower than the vocal cords and not higher than the lower nasopharynx, said Dr. O’Malley.
Robotic-assisted surgery has a potential use not only for treating benign and malignant tumors, but also for treating inflammatory conditions such as chronic lingual tonsillitis in the back of the tongue. When a patient complains of chronic tongue base tonsillitis that does not respond to antibiotics, it is a real problem for the patient and the surgeon, Dr. Weinstein said. It is very difficult to remove the tongue base tonsils using standard techniques. At the University of Pennsylvania, preliminary studies in a few patients suggest that robotic-assisted surgery takes only about 15 minutes to remove the tongue base tonsils, and no further infections have been seen with long-term follow-up.
Dr. Weinstein and his group conducted a study using robotic-assisted surgery to perform radical tonsillectomy in 27 patients with tonsil cancer; a review of these cases was presented in April at the Combined Otolaryngology Spring Meeting. Most of these patients would have been treated with chemotherapy and radiotherapy, which, studies suggest, may have a negative impact on swallowing function. At six-month follow-up, only one of these patients had swallowing difficulty. Robotic surgery allowed surgical staging and avoidance of chemotherapy and radiotherapy with their attendant side effects in approximately half of these patients, all of whom had good swallowing function, he said.
Although long-term oncologic and functional results still need to be evaluated, to date there have been no cancer recurrences in this group.
It’s too early to determine whether oncologic outcomes will be similar to those achieved by chemotherapy and radiotherapy. The hope is that robotic-assisted surgery can preserve function with equally good oncologic outcomes, he said.
Another potential application of robotic surgery may entail transaxillary approaches to the thyroid, said F. Christopher Holsinger, MD, Assistant Professor of Head and Neck Surgery at the M. D. Anderson Cancer Center in Houston. Dr. Holsinger attended a course in robotics techniques last year that was offered at University of Pennsylvania. A study to assess functional outcomes in TORS is now pending IRB approval at M.D. Anderson.
Benefits to Patients
The benefits of TORS are numerous, according to surgeons interviewed for this article.
Some tonsil- or tongue-based cancers require large, complex, long operative procedures involving tracheostomy, complex skin reconstruction, and splitting the jaw, Dr. Weinstein explained. Blood transfusions are often required for these large open procedures. Only one patient who underwent TORS at the University of Pennsylvania required a blood transfusion, he commented.
We can avoid tracheostomy, complex skin reconstruction, and jaw splitting with robotics, using one three-hour procedure and then a second procedure for another three hours to take out lymph nodes, Dr. Weinstein said.
Robotics causes less injury to speech and swallowing structures, and less cosmetic damage, because it is less invasive than open surgery. Also, robotics shortens surgical times from six to 18 hours to two hours. Robotics also allows good control of bleeding, Dr. O’Malley added. With robotics, we can use both hands for surgical procedures, whereas endoscopic-based procedures are typically done with one hand, because the other hand holds the endoscope.
For other lesions, such as lesions in the supraglottis or larynx, the major advantages of robotics over open surgery are better access and faster surgical times.
Robotics offers a three-dimensional visual environment that puts the surgeon right where the surgery is happening. This unique perspective allows the surgeon to operate at the same level as the anatomy of interest. ‘Master’ control manipulators then allow the surgeon to use precise instruments in situations and in ways that were never before possible. For instance, the surgeon can rotate a given instrument 540 degrees and overcome the limitations of the human wrist, said Dr. Holsinger.
Limitations of Robotic-Assisted Surgery
One limitation of robotic-assisted surgery, with present techniques, is limited access. Some tumors are located too deep in the laryngopharynx to allow access, Dr. Weinstein said. With current technology, it is difficult to have greater access beyond present boundaries (i.e., tumors not lower than the vocal cords and not higher than the lower nasopharynx), Dr. O’Malley commented.
Also, at present there are no robotic instruments for drilling and removing bone. ENTs use a lot of drills, and it is expected that companies will be developing rongeurs and drills along with the software to drive these tools using the robot, Dr. O’Malley said.
It would also be desirable to have haptic or tactile feedback with robotics, such as is used by the military. At present, we have to rely on the tremendous three-dimensional visualization for feedback. As we take the surgical robot into new frontiers, such as skull-based surgery, it would be advantageous to have a system for tactile feedback, Dr. O’Malley said.
According to Dr. Holsinger, at present the CO2 laser is used with endoscopy to resect tumors and develop planes, but this has limitations. The ideal technique would combine the precise tissue handling properties of the CO2 laser with robotics. Research efforts are aimed at trying to find an optimal laser to combine with robotics, he said.
Training for Robotic-Assisted Surgery
The first workshop and formal educational program in robotics for head and neck was taught by Drs. Weinstein and O’Malley at the Intuitive Surgery Training Facility in California. That course included a core group of 12 head and neck surgeons from several institutions, including the Mayo Clinic, M. D. Anderson Cancer Center, and Mount. Sinai Medical Center. These individuals, including Dr. Holsinger, have now gone back to their respective institutions to initiate IRB-approved studies of TORS. Drs. Weinstein and O’Malley are conducting an IRB-approved study at the University of Pennsylvania that is still open. Thus far, 120 patients have entered the trial, and only two of them had anatomy that was inaccessible for a robotic-assisted procedure.
If TORS gains FDA approval based on these studies, the University of Pennsylvania will offer a training course in robotics procedures. The plan is to have a two-day course, with one day in the laboratory and another day of observation. Other institutions will undoubtedly offer courses in robotics as well, said Dr. Weinstein.
The University of Pennsylvania also plans to erect a special building for research and training in robotics, Dr. O’Malley said. We hope that the people we trained [at the first training session last year] will set up their own programs and spread the seed-establishing more research and developing new procedures and applications, he added.
The Future of Robotics
In the future, it would be ideal to have smaller instruments to allow deeper access beyond presently defined boundaries, Dr. Weinstein said. Smaller instruments will be developed to allow access to the nasal cavity as an alternative to endoscopic surgery.
While the first TORS skull base surgery cases have been reported from the University of Pennsylvania, further miniaturization of instruments and more flexible instruments, tactile feedback, and techniques for skull based procedures will probably be developed, Dr. O’Malley said. At M. D. Anderson, transoral approaches through the nose to the skull base are being studied in the cadaver model using robotic-assisted techniques. If skull base procedures can be done with robotics, surgery could carry much less morbidity.
Another pressing need, according to Dr. O’Malley, is two-handed, delicate, fine magnification procedures for the vocal cords or subglottis, which may also be applicable to skull base surgery. The technology is not there yet, but it should be in the next five or 10 years. The team at the University of Pennsylvania is studying robotic-assisted surgery for skull-based procedures. There is a need to refine and hone instruments for these procedures, Dr. O’Malley continued.
We are just at the beginning of discovering uses for robotics in head and neck surgery, similar to when DOS was the only operating system for computers. At present, robotics allows removal of tumor and provides a bird’s eye view in areas that heretofore had difficult transoral access. I don’t have a crystal ball, but the types of approaches for robotics will continue to increase dramatically, Dr. Weinstein said. For me and for my patients, it is an incredibly exciting time.
There is unlimited potential for the application of robotics in head and neck surgery, said Dr. O’Malley. He predicted that 80% of the range of types of ENT surgeries will be performed with some aspects of robotics within the next 25 years, including head and neck, ear, sinus, certain cosmetic and skull-based procedures.
©2007 The Triological Society