Robotic surgery Applications in Otolaryngology & HNS
An Emerging Wave.
A role of Robotic surgery technology in otolaryngology is beginning to emerge, particularly where precision is required or visualization is limited, and there are a number of pioneering contributions. The first otolaryngologic application of robotics occurred as early as 2002 with several reports from the Terris group at the Medical College of Georgia exploring endoscopic neck procedures. The first human application was described by McLeod and Melder with a case report of excision of a vallecular cyst. Hockstein and colleagues further pursued oral and oropharyngeal applications of robotic technology with a stepwise experimental approach. Finally, interest in robotic skull base surgery has emerged with the work of Hanna and colleagues.
The first use of robotics for otolaryngologic applications was explored in a porcine model of neck surgery that included parotidectomy, submandibular gland resection, and selective neck dissection. This work built on previous promising findings for totally endoscopic neck surgery (also described by Terris and collaborators) and provided proof of principle, in that the safety and efficacy of endorobotic neck surgery was demonstrated, and quickly established that advantages in duration of surgery could be easily achieved with the addition of robotic technology.
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
The purpose of these studies was to learn how to position the da Vinci arms in a patient's mouth, Dr. weinstein 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.
Figure.Transoral robotic surgery, offering a three-dimensional visual environment, is being studied for use in a number of head and neck procedures.
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.
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 as it is 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.
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.
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. 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.
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.
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,
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.
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 saidtransoral 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.
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,.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.
Emeritus Prof. & Head