Robotic skull base surgery: preclinical investigations to human clinical application.

OBJECTIVE To develop a minimally invasive surgical technique for the treatment of parapharyngeal space and infratemporal fossa skull base neoplasms using the technical and optical advantages of robotic surgical instrumentation. DESIGN A robotics skull base surgery program at the University of Pennsylvania, Philadelphia, was initiated in the fall of 2005. Six experimental procedures focusing on developing approaches to the parapharyngeal space and infratemporal fossa were performed on a total of 2 cadavers and 1 mongrel dog. Based on the preclinical work, transoral robotic surgery (TORS) was then performed in February 2007 on 1 human patient with a parapharyngeal to infratemporal fossa cystic neoplasm as part of a large prospective human trial. SETTING In each cadaver and in the dog, a TORS approach to parapharyngeal space and infratemporal fossa was performed bilaterally and in an approved training facility using the da Vinci Surgical System. For the human surgical case, a TORS approach was evaluated on one side for a benign neoplasm. The human patient underwent TORS of the parapharyngeal space and infratemporal fossa under an institutional review board-approved prospective clinical trial. PATIENTS For the human clinical trial, a TORS approach was evaluated for a patient with a benign neoplasm of the parapharyngeal space and infratemporal fossa. MAIN OUTCOME MEASURES The ability to access and dissect tissues within the various areas of the parapharynx and infratemporal fossa was evaluated, and techniques to enhance visualization and instrumentation were developed. RESULTS Using TORS approaches permitted excellent access, visualization, and tissue dissection within the parapharyngeal space and infratemporal fossa in both the cadaver and canine experiments. In the first known human surgical case, TORS was used to remove a parapharyngeal space and infratemporal fossa cystic neoplasm. Wide visualization, followed by complete resection using the identical techniques developed in the preclinical models, was achieved. The robotic procedure allowed adequate and safe identification of the internal carotid artery and cranial nerves, and excellent hemostasis was achieved with no complications during or after surgery. CONCLUSIONS The TORS approaches provided excellent 3-dimensional visualization and instrument access that allowed successful parapharyngeal space and infratemporal fossa surgical resections from cadaver models to the first known human patient application. Robotic surgery for the skull base holds potential as a minimally invasive approach to skull base neoplasms; however, continued development and investigation is warranted in a prospective human clinical trial before final conclusions can be drawn as to the full advantages and limitations of this approach.