CT-derived surgical corridor anatomy predicts console time beyond body mass index in single-port hairline robotic thyroidectomy

Body mass index (BMI) and other anthropometric measures are widely used as surrogates for operative difficulty in robotic thyroidectomy, yet they may poorly represent the three-dimensional anatomy of the surgical corridor. We investigated whether computed tomography (CT)-derived characteristics of the surgical corridor predict console time in single-port hairline approach thyroidectomy (SPHAT), independently of BMI. We analyzed 125 consecutive robotic thyroid lobectomies with ipsilateral central neck dissection performed by a single surgeon operating within a confirmed expert phase, defined by the absence of a temporal trend in operative time. Corridor length, geodesic tortuosity, and peritrajectory fat heterogeneity were quantified from preoperative CT. Associations with console time were assessed using Spearman correlation and sequential multivariable linear regression. Console time correlated with corridor length (ρ = 0.210, p = 0.019), geodesic tortuosity (ρ = 0.190, p = 0.033), and peritrajectory fat heterogeneity (ρ = 0.319, p < 0.001), but not with BMI (ρ = 0.160, p = 0.075). On multivariable analysis, geodesic tortuosity and peritrajectory fat heterogeneity were independent predictors of console time (Model A R²=0.138). Peritrajectory fat heterogeneity remained significant across all model specifications (β = 2.22–2.43 min per standard deviation, all p ≤ 0.002). Adding BMI did not improve model fit (R²=0.144), and BMI was non-significant after adjustment (p = 0.395). Objectively quantified anatomy of the surgical corridor—particularly peritrajectory fat heterogeneity—provides an independent signal of operative difficulty in SPHAT that is not captured by BMI. Because both metrics are derivable from routine preoperative CT, corridor characterization may serve as an objective adjunct for assessing operative complexity and refining preoperative planning.