Anatomical landmarks for transoral robotic tongue base surgery: comparison between endoscopic, external and radiological perspectives.
OBJECTIVE
To describe the transoral viewpoint of the tongue base anatomy, focusing on a superior to inferior perspective, which is less familiar to the head and neck surgeon but, at the same time, worthy to be known given the expanding interest and diffusion of the transoral robotic technique.


METHODS
Seven heads were dissected, two with the Da Vinci(®) robotic system, three by means of a transoral endoscopic approach and another two by means of a lateral "traditional" external approach. Ten normal patients, with normal oral cavity and oropharynx, were studied as control samples by means of a 3-T MRI scanner.


RESULTS
Major neurovascular elements are placed laterally and deeply within the tongue base. Dissection within intrinsic and genioglossus muscles is safe because the main trunk of the lingual artery lies on the lateral surface of genioglossus muscle, covered by the hyoglossus muscle. The hypoglossal nerve, with its comitant vein, is more lateral, lying on the external surface of the hyoglossus muscle. Radiological evaluation can visualize important details of this complex anatomy. The position of the vessels can be directly identified, whereas major nerves are more difficult to be visualized unless they are surrounded by fibro-fatty tissue.


CONCLUSIONS
A medial to lateral dissection of the tongue base can be considered safe. A strict collaboration with the radiologist is helpful in approaching these cases by means of a robotic technique and in improving a true 3D understanding of this complex anatomy.
U.O. Otorinolaringoiatria, Ospedale di Circolo e Fondazione Macchi, Varese, Italy. iacopodallan@tiscali.it
Iacopo
I
Dallan
Veronica
V
Seccia
Lorenzo
L
Faggioni
Paolo
P
Castelnuovo
Filippo
F
Montevecchi
Augusto Pietro
AP
Casani
Manfred
M
Tschabitscher
Claudio
C
Vicini
D059925:Anatomic Landmarks; D002102:Cadaver; D004724:Endoscopy / Q000379:methods*; D005927:Glossectomy / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007002:Hypoglossal Nerve / Q000033:anatomy & histology / Q000601:surgery; D008279:Magnetic Resonance Imaging / Q000379:methods; D019647:Oral Surgical Procedures / Q000379:methods; D009960:Oropharynx / Q000033:anatomy & histology / Q000601:surgery; D012371:Robotics / Q000379:methods*; D012680:Sensitivity and Specificity; D014059:Tongue / Q000033:anatomy & histology / Q000294:innervation / Q000601:surgery*