Zuckerkandl's tubercle is a useful anatomic landmark for dissecting the recurrent laryngeal nerve during thyroid surgery

Abstract

Objective To study the anatomic characteristics of Zuckerkandl's tubercle (ZT) and its clinical relevance as an anatomic landmark of the recurrent laryngeal nerve (RLN) in thyroid surgery.Methods This study involved 147 (106 with benign thyroid diseases and 41 with malignancies) patients who underwent thyroidectomy.ZT was measured and classified based on the Pelizzo classification.The relationship between ZT and the RLN and the relationship between the RLN and the inferior thyroid artery were recognized and classified.Results 233 (107 left and 126 right) thyroid gland lobes were dissected and ZT was identified in most patients (left in 93.5％ and right in 96.0％).The distribution of ZT according to grade was as follows:Grade 0,left 16.0％ and right 13.2％ ; Grade Ⅰ,left 32.0％ and right 27.3％ ; Grade Ⅱ,left 46.0％ and right 44.6％ ; Grade Ⅲ,left 6.0％ and right 14.9％.There was no significant difference on classification between the left-sided and right-sided ZTs.In terms of the relationship between the ZT and the RLN,it was classified as follows:Type A,left 92.9％ and right 93.3％ ; Type B:left 0 and right 0; Type C:left 7.1％ and right 6.7％.Similarly,there was no significant difference between the left sided and the right sided.The ZT grade was correlated with the course of the RLN:the higher the ZT grade was (that is,the greater the size of the ZT),the more often was the course of RLN behind the back of the ZT; the lower the ZT grade (that is,the smaller the size of the ZT),the more often was the course of RLN running by the lateral of the ZT.Considering the incidence of being dangerous type of RLN,the right sided (19.0％) was higher than the left sided (8.3％).The relationship between the ZT and the RLN does not relate to RLN course across the inferior thyroid artery.Conclusions As an important anatomic landmark,the ZT is essential for locating and dissecting the RLN during thyroid surgery,and its classification is a guide to RLN dissection and preservation. Key words: Thyroidectomy; Recurrent laryngeal nerve; Zuckerkandl' s tubercle; Anatomic landmark