Robotic endoscopic surgery of the skull base: a novel surgical approach

OBJECTIVE: To describe a novel robotic surgical approach that allows adequate endoscopic access for resection of tumors involving the anterior and central skull base and allows 2-handed, tremor-free, endoscopic dissection and precise suturing of dural defects. DESIGN: Transnasal endoscopic approaches are being increasingly used for surgical access and resection of tumors of the anterior and central skull base. One major disadvantage of this approach is the inability to provide watertight dural closure and reconstruction, which limits its safety and widespread adoption in surgery of intracranial skull base tumors. Other disadvantages include limited depth perception and several ergonomic constraints. Four human cadaver specimens were used for this study. The surgical approach starts with bilateral sublabial incisions and wide anterior maxillary antrostomies (Caldwell-Luc). Transantral access to the nasal cavity is gained through bilateral wide middle meatal antrostomies. A posterior nasal septectomy facilitates bilateral access by joining both nasal cavities into 1 surgical field. The da Vinci Surgical System is then "docked" by introducing the camera arm port through the nostril and the right and left surgical arm ports through the respective anterior and middle antrostomies, into the nasal cavity. A 5-mm dual-channel endoscope coupled with a dual charge-coupled device camera is inserted in the camera port and allows for 3-dimensional visualization of the surgical field at the surgeon's console. Using the robotic surgical arms, the surgeon may perform endoscopic anterior or posterior ethmoidectomy, sphenoidotomy, or resection of the middle or superior turbinates depending on the extent of needed surgical exposure. In addition, resection of the cribriform plate is performed robotically with sharp dissection of the skull base. The dural defect is then repaired with a 6-0 nylon suture. RESULTS: Adequate access to the anterior and central skull base, including the cribriform plate, fovea ethmoidalis, medial orbits, planum sphenoidale, sella turcica, suprasellar and parasellar regions, nasopharynx, pterygopalatine fossa, and clivus, was obtained in all cadaveric dissections. The 3-dimensional visualization obtained by the dual-channel endoscope at the surgeon's console provided excellent depth perception. The most significant advantage was the ability of the surgeon to perform 2-handed tremor-free endoscopic closure of dural defects. CONCLUSIONS: Transantral robotic surgery provides adequate endoscopic access to the anterior and central skull base. To our knowledge, this is the first study to report the feasibility and advantages of robotic-assisted endoscopic surgery of the skull base. This novel approach also allows for 3-dimensional, 2-handed, tremor-free endoscopic dissection and precise closure of dural defects. These advantages may expand the indications of minimally invasive endoscopic approaches to the skull base.