Benefits and challenges of robotic technology in otolaryngology

The attributes of robotic technology that have resulted in their widespread use in manufacturing—steady, precise movements and untiring action in difficult positions and confined spaces—are well suited to surgical procedures that benefit from these qualities . Furthermore, the move toward minimal access and minimally invasive surgery, with the goals of less pain, shorter hospital stays, faster recoveries, and smaller incisions and scars, are well served by robotic technology . One of the greatest benefits of robotic surgical technology is the potential to operate in smaller confines than possible using other methods, including manual endoscopic methods . Ironically, the introduction of robotic technology to the specialty of otolaryngology has been limited by the same anatomic constraints that make the technology so appealing: the anatomic areas that currently are accessed using minimally invasive, endoscopic methods may not accommodate the robotic apparatus . For pediatric patients the goals of minimally invasive surgery are particularly poignant, but these limitations are most acute in pediatric patients because of the size of their anatomy and proportionately smaller surgical work spaces .

Surgical approach with robotic technology in pediatrics

Despite the challenges and limitations, pediatric surgeons have been quick to adopt robotic technology in the pursuit of optimal surgical care for children . Laparoscopic, pelviscopic/urologic, and limited cardiac procedures, in particular, have benefited from the robotic approach , and both animal models and studies using human cadavers have demonstrated the feasibility of applying the robotic endoscopic approach to many other areas, including head and neck procedures .

Surgical reconstruction of the airway has been performed most commonly through an open, transcervical approach . In a move toward minimally invasive technique, transoral surgery of the larynx and airway typically is attempted using a microscope and long, manually controlled instruments. This approach is limited by two inherent constraints: surgeon tremor and dependence on line-of-sight from the microscope objective to the target anatomic structure. Long instruments required to perform transoral microlaryngeal surgery create a fulcrum effect that magnifies movements, so any small amount of tremor that is present proximally at the surgeon’s hand is translated to a large excursion at the tip of the instrument. These inadvertent movements are magnified further by the operating microscope. Additionally, one is limited to structures that are within the view of the microscope objective. Therefore many lateral or subglottic structures are difficult to view and challenging to operate on. Although some daring surgeons have reported their results for cricoid split with rib grafting using endoscopic techniques , these techniques push the limits of endoscopic technique for reasons similar to those that limit microscopic endolaryngeal surgery.

The surgical robotic system avoids these limitations and adds other benefits as well. First, because robotic instruments are controlled through a computer-assisted console, tremor is filtered out. An additional benefit is that of “motion scaling,” whereby large excursions by the surgeon’s hands at the control console can result in very fine movements at the tips of the robotic instruments. The result can be very fine, precise movements that are proportional to the surgeon’s movements but that are simply scaled down. Because the robotic system depends on an endoscope for the operative view, angled endoscopes can provide views “around corners,” avoiding the line-of-sight limitation of the microscope. In parallel to this benefit is the ability of the robotic instruments to flex: unlike straight, manually controlled endoscopic instruments, robotic instruments incorporate a “wrist,” and some are flexible, allowing them to reach around corners. Finally, the current standard of surgical robotic technology employs a sophisticated multibarreled endoscope that provides a detailed three-dimensional (3D) view. This 3D visualization results in enhanced surgical ability and reduced operating times . Together, these features present the potential for improved transoral airway surgery using the surgical robot .

Surgical approach with robotic technology in pediatrics

Despite the challenges and limitations, pediatric surgeons have been quick to adopt robotic technology in the pursuit of optimal surgical care for children . Laparoscopic, pelviscopic/urologic, and limited cardiac procedures, in particular, have benefited from the robotic approach , and both animal models and studies using human cadavers have demonstrated the feasibility of applying the robotic endoscopic approach to many other areas, including head and neck procedures .

Surgical reconstruction of the airway has been performed most commonly through an open, transcervical approach . In a move toward minimally invasive technique, transoral surgery of the larynx and airway typically is attempted using a microscope and long, manually controlled instruments. This approach is limited by two inherent constraints: surgeon tremor and dependence on line-of-sight from the microscope objective to the target anatomic structure. Long instruments required to perform transoral microlaryngeal surgery create a fulcrum effect that magnifies movements, so any small amount of tremor that is present proximally at the surgeon’s hand is translated to a large excursion at the tip of the instrument. These inadvertent movements are magnified further by the operating microscope. Additionally, one is limited to structures that are within the view of the microscope objective. Therefore many lateral or subglottic structures are difficult to view and challenging to operate on. Although some daring surgeons have reported their results for cricoid split with rib grafting using endoscopic techniques , these techniques push the limits of endoscopic technique for reasons similar to those that limit microscopic endolaryngeal surgery.

The surgical robotic system avoids these limitations and adds other benefits as well. First, because robotic instruments are controlled through a computer-assisted console, tremor is filtered out. An additional benefit is that of “motion scaling,” whereby large excursions by the surgeon’s hands at the control console can result in very fine movements at the tips of the robotic instruments. The result can be very fine, precise movements that are proportional to the surgeon’s movements but that are simply scaled down. Because the robotic system depends on an endoscope for the operative view, angled endoscopes can provide views “around corners,” avoiding the line-of-sight limitation of the microscope. In parallel to this benefit is the ability of the robotic instruments to flex: unlike straight, manually controlled endoscopic instruments, robotic instruments incorporate a “wrist,” and some are flexible, allowing them to reach around corners. Finally, the current standard of surgical robotic technology employs a sophisticated multibarreled endoscope that provides a detailed three-dimensional (3D) view. This 3D visualization results in enhanced surgical ability and reduced operating times . Together, these features present the potential for improved transoral airway surgery using the surgical robot .

Transoral robotic surgery

The group at the University of Pennsylvania has described their step-wise development of the transoral robotic approach in great detail. They examined the feasibility of this approach using the da Vinci surgical robot (Intuitive Surgical, Inc., Sunnyvale, California) with an airway mannequin , followed by studies using human cadavers and by transoral robotic surgical procedures in animal models and finally by procedures in adult patients in the operating room . Their experience in this development has been documented meticulously in the literature, and the reader interested in pursuing transoral robotic surgery is encouraged to review their work, now presented in text format .