Prevalence and implications of thyroid related embryological remnants: A prospective study of 1118 total thyroidectomies.

Abstract

Modern thyroid surgery has undergone a paradigm shift from subtotal thyroidectomy to an extended total thyroidectomy (TT) even for benign disorders. This entails removal of all embryological remnants even in benign disorders. To study the prevalence of various embryological remnants of the thyroid and surgical utility and implications in preventing complications. Retrospective study of total thyroidectomies done by a single endocrine surgeon by standardized technique. A detailed search of all embryological rests including Pyramidal tract (PT), Tubercle of Zuckerkandl (TZ), and Thyro-thymic thyroid rests (TTR) were done in 1118 patients undergoing TT over 6 years. The cases with and without TTR were divided as Group A and B, respectively. Their prevalence and impact on parathyroid preservation and other clinical parameters were analysed. Descriptive analyses. Out of the 1118 TT cases, TTR was seen in 230 (20.57%) cases, TZ in 598 (53.48%), cases and PT in 641 (57.33%) cases. Among group-A (<i>n</i> = 230), 213 had unilateral and 17 had bilateral TTR with 51 (22.17%) having retrosternal extension. Compressive symptoms, presence of TZ and PT were also significantly higher in group A. On follow up the incidence of temporary hypoparathyroidism was significantly higher in group-A, where as permanent hypoparathyroidism, temporary and permanent vocal cord palsy were comparable between the two study groups. Embryological remnants related to thyroid are not uncommonly encountered during total thyroidectomy. A thorough search and complete removal is crucial for the successful outcome of the procedure.