An evaluation score of the difficulty of thyroidectomy considering operating time and preservation of recurrent laryngeal nerve.

The purpose of this study was to edit a renovated thyroidectomy difficulty scale (rTDS) in order to identify underlying thyroid diseases with a longer operative time and higher technical difficulty, also considering preservation of recurrent laryngeal nerve. We developed a renovated scale with a maximum score of 20 points by creating a form in which five variables were considered: vascularity, friability, mobility/fibrosis, gland size and difficulty in preservation of the recurrent laryngeal nerve. Two surgeons separately evaluated each of these. Through a simple linear regression analysis, we have analyzed the relationship between rTDS score and operative times, and between rTDS score and preservation of recurrent nerve. Eventually, Spearman's rank correlation coefficient has been used in order to evaluate our double-blind study. Our cohort included 131 patients undergoing total thyroidectomy. The mean of the rTDS was 9.00 ± 3.67 for Surgeon A and 8.31 ± 3.42 for Surgeon B, with Spearman's rank correlation coefficient between surgeons of 0.85 (p < 0.0001). We have shown that the rTDS score significantly influences the operating times (R2 = 0.44 for surgeon A, R2 = 0.46 for B, p < 0.0001 for both). Moreover, we can say that the rTDS score significantly influences preservation of the recurrent nerve (R2 = 0.37, Beta 0.61, 8.84 t test, p < 0.0001). Our rTDS is a useful tool and, thanks to it, we identified hyperthyroidism and goiter as the hardest underlying disease for surgery. Thus our scale could change operative approach, resulting in better surgeries' scheduling and identification of pathologies that require higher attention.