Can Biometric Measures Predict TORS Feasibility?

Abstract

Objective: 1) Investigate whether subjective evaluation of patient suitability for Transoral Robotic Surgery (TORS) is reliable. 2) Establish if TORS feasibility can be assessed using anthropometric measures and Mallampatti grade. 3) Determine which biometric characteristics warrant further clinical evaluation.

Method: Cadaver study (n = 42) conducted between April 2010-2012. Seven anthropometric measurements and Mallampati grade were recorded. Three head and neck surgeons assessed TORS feasibility. Adequate visualization of tonsil, tongue base, vallecula, and epiglottis were recorded using 2 TORS mouth gags. Significant anthropometric differences between full and suboptimal visualisation groups were identified.

Results: There was a negative correlation between subjective difficulty impression and actual transoral visualization for all anatomical regions (R² = 0.32, P < .05). Six anthropometric measures were identified whose mean values were significantly different between full and suboptimal transoral visualization groups. Suboptimal visualization of the tongue base was associated with shorter mean sterno-mental (P < .01) and cricoid-mental (P = .02) lengths and greater mean neck circumference (P = .04). Suboptimal visualization of the vallecula and epiglottis were associated with a short ramus width (P = .03) and long ramus length (P = .05). The mean Mallampati grade was higher in the suboptimal visualization group for tongue base (P < .01), vallecula (P < .03), and epiglottis (P < .04).

Conclusion: Subjective assessment is an unreliable predictor of TORS feasibility. Anthropometric measures of the neck, mandible, and Mallampati grade are valuable indicators which can potentially be used to devise a weighted predictive scale. Further clinical evaluation is warranted to determine the true predictive value of these anthropometric measures and Mallampati grade.