Abstract B29: Intraoperative identification of critical vascular landmarks of the lateral oropharynx and tongue base using transoral robotic ultrasound (TORUS)

Abstract

Abstract Transoral robotic surgery (TORS) is an expanding domain of minimally invasive surgery, which has been employed since 2009 in the United States primarily for the management of upper aerodigestive tract tumors (1). Tongue base reduction is an emergent application of TORS in obstructive sleep apnea (2). The technique uses the da Vinci surgical system (Intuitive Surgical, Sunnyvale, CA, USA) to deliver a camera and instruments on three robotic arms. Identification of large-caliber blood vessels emanating from the external carotid artery is a critical step in TORS for tongue base and lateral oropharynx disease. Specifically, control of the lingual artery and facial artery branches is necessary for safe surgical dissection (3). Previously, the use of ultrasound has been described in TORS for the intraoperative localization of retropharyngeal lymph nodes (4-6). One case series in the literature has described the use of a handheld ultrasound probe in TORS for pharyngeal and base of tongue tumors (7). We describe the use of a novel miniaturized ultrasound probe (Mindray North America, San Jose, CA, USA) capable of being manipulated by the da Vinci arm to allow intraoperative transoral robotic ultrasonography (TORUS). The ergonomics of this system was evaluated in human cadavers, followed by an efficacy trial in a porcine model. Two surgeons, one experienced (FCH) and one novice (VV), performed ultrasound-guided identification of the lingual and buccal arteries. Time to identification was measured. Mean time in seconds for the localization of the buccal artery was 53.0 for the experienced robotic surgeon versus 27.5 for the novice surgeon (p=0.10), and 55.0 versus 268.0, respectively, for the lingual arteries (p=0.003). Herein, we show the feasibility of TORUS to identify the large-caliber blood vessels of the oral cavity and oropharynx during TORS. This platform may allow for safer dissection, without a significant increase in operative time or need to interrupt the robotic setup. Future directions include human clinical trials, measurement of tumor volume, depth of invasion, and identification of additional surgical landmarks. Citation Format: Wen P. Liu, F. Chris Holsinger, Varun Vendra. Intraoperative identification of critical vascular landmarks of the lateral oropharynx and tongue base using transoral robotic ultrasound (TORUS) [abstract]. In: Proceedings of the AACR-AHNS Head and Neck Cancer Conference: Optimizing Survival and Quality of Life through Basic, Clinical, and Translational Research; 2019 Apr 29-30; Austin, TX. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(12_Suppl_2):Abstract nr B29.