Preoperative investigations in thyroglossal duct cyst surgery: a 9-year experience and proposed practice guide.

INTRODUCTION: Thyroglossal duct cysts (TGDC) are the commonest midline developmental cyst and have a bimodal age distribution. They usually develop in an infrahyoid position. A National survey of TGDC practice among otolaryngologists in 2012 recommended preoperative investigation with ultrasound, with or without blood tests.

METHODS: Retrospective analysis of preoperative investigation for clinically diagnosed TGDC surgeries between 2012 and 2020 in a single tertiary centre was undertaken. This was collated alongside postoperative outcomes (histology, recurrence, hypothyroidism). Comparison was made with the 2012 national survey.

RESULTS: Ninety-five cases of thyroglossal duct surgery in children and adults were studied. Demographic data were comparable to the literature. Ultrasonography was the most commonly used preoperative investigation. Histology of 71% of excised cysts confirmed TGDC with another 8% reported as development cysts. The excision of the cyst with a cuff of strap muscles and middle portion of hyoid bone had the lowest recurrence rate, which was 4% overall in this study. There were no cases of ectopic thyroid tissue or postoperative hypothyroidism.

DISCUSSION AND CONCLUSION: Nearly a decade of thyroglossal duct cyst excisions in a large-volume unit gave detail on actual preoperative practice and outcomes. Practice was found to be consistent overall with the 2012 recommendations although not standardised across all cases. From this experience, and a literature review, a visual guide on preoperative investigations for different age groups in the form of a flow chart is proposed to reduce risk of complications while avoiding unnecessary investigations.