楯谷 一郎

Objective: The application of the da Vinci Surgical System in neurosurgery is limited due to technical difficulties requiring precise maneuvers and small instruments. This study details the advantages and disadvantages of robotics in neurosurgery and the reachable range of the transoral approach to lesions of the skull base and upper cervical spine.Methods: In a cadaver study, the da Vinci Xi robot, lacking haptic feedback, was utilized for sagittal and coronal approaches on 5 heads, facilitating dura suturing in 3, with a 30°-angled drill for bone removal.Results: Perfect exposure of all the nasopharyngeal sites, clivus, sellar, and choana, including the bilateral eustachian tubes, was achieved without any external incisions using this palatal split approach of transoral robotic surgery. The time required to perform a single stitch, knot, and complete single suture in robotic suturing of deep-seated were significantly less compared to manual suturing via the endonasal approach.Conclusion: This is the first report to show the feasibility of suturing the dural defect in deep-seated lesions transorally and revealed that the limit of reach in the coronal plane via a transoral approach with incision of the soft palate is the foramen ovale. This preclinical investigation also showed that the transoral robotic approach is feasible for lesions extending from the sellar to the C2 in the sagittal plane. Refinement of robotic instruments for specific anatomic sites and future neurosurgical studies are needed to further demonstrate the feasibility and effectiveness of this system in treating benign and malignant skull base lesions.

Transoral robotic surgery (TORS), introduced by Weinstein et al. in 2005, has been widely adopted as a minimally invasive procedure, particularly for the treatment of patients with early stage oropharyngeal cancer. TORS is typically performed using the da Vinci Surgical System, similar to robot-assisted surgeries for other malignancies. The main difference between TORS and these other robot-assisted surgeries is that it is performed through the natural orifice of the mouth, which limits the surgical working space, and that it progresses from the lumen of the pharynx to the deeper tissues. The advantages of TORS are mainly due to the benefits of using the da Vinci Surgical System, such as three-dimensional high-definition images, magnification, multiple forceps articulation, tremor-stabilization function and motion scale function. To date, many big data and meta-analyses have shown that TORS is superior to conventional surgeries, such as open surgery, in terms of oncological outcomes, post-operative functionality and quality of life. In Japan, TORS is expected to spread across the country, as it has been covered by health insurance since April 2022. This review highlights the procedures of TORS, its unique aspects, its unparalleled advantages as a minimally invasive surgery for treating laryngeal and pharyngeal cancers, and its current status in Japan.