Purpose: In the past, midline mandibulotomies and lateral pharyngotomies were required for resection of many oropharyngeal tumors. The morbidity of such surgery drove a movement towards chemoradiation as primary treatment; however, this approach can result in increased rates of locoregional recurrence, and crippling dyshapgia, dysarthria, xerostomia and chronic pain. Trans-Oral Robotic Surgery (TORS) offers a minimally invasive solution that can be used in isolation, or combined with radiation therapy, to gain all the benefits of locoregional control, with none of the morbidity associated with traditional surgical access or high dose primary radiotherapy. Current efforts in trans-oral robotic resections have been limited by oropharyngeal defects that are left to granulate, causing protracted pain and significant scarring. Trans-oral robotic free flap reconstruction is the next logical step in this new therapeutic approach.
Methods: The da Vinci Surgical System (Intuitive Surgical, Sunnyvale, CA) was set up in three separate scenarios: a dry lab model of the oropharynx consisting of a prosthetic, cylindrical orifice with an internal defect; a porcine wet lab with base-of-tongue resection and full-thickness skin graft reconstruction, and a cadaveric model with a lateral, hypopharyngeal resection consisting of soft palate, base of tongue and tonsillar fossa, followed by free radial forearm flap reconstruction. The vascular pedicle was externalized through a lateral pharyngotomy and anastamosed to the facial vessels. The entire intra-oral component, including resection and flap inset, suturing and flap trimming were performed remotely using robotic instrumentation with the surgeon seated at the remote command center.
Results: The dry lab model demonstrated that the robotic arms and camera could accommodate the complex movements required for suturing in a confined space with the da Vinci system. The porcine model with base of tongue resection and full-thickness skin grafting demonstrated the feasibility of autogenous reconstruction of an oropharyngeal defect in a live animal model. The cadaver study demonstrates the direct applicability of free flap reconstruction of a complex oropharyngeal defect such as might be created by trans-oral robotic resection of a squamous cell carcinoma of the tonsil. The inset of a thin radial forearm flap was used to recreate the complex, three dimensional contours of the soft palate, tonsillar fossa, posterior hypopharynx and base of tongue. A small lateral pharyngotomy was sufficient to pass the pedicle trans-cervically for standard microvascular anastamosis to the facial vessels.
Conclusion: Exceptional resolution, high magnification and three-dimensional optics, combined with wristed motion and tremor elimination, allow for elegant reconstruction of complex oropharyngeal defects using Trans-oral robotic free flap reconstruction. Robotic instrumentation for flap inset deep in the oropharynx can be combined with traditional microsurgical revascularization in the external neck. With these techniques, plastic surgery can continue to provide recipient site specific, low morbidity reconstruction in the context of a new era of robotic surgical extirpation.