Comparison of delayed bleeding to immediate bleeding following thyroidectomy.

It is important to identify risk factors for post-thyroidectomy bleeding requiring airway intervention or reoperation. Therefore, we aimed to compare the characteristics of patients with postoperative bleeding after thyroid surgery according to the period until reoperation. We conducted a retrospective study analyzing data between April 2009 and July 2022 and included 126 patients who had postoperative bleeding. The patients were grouped according to the period between thyroidectomy and reoperation due to bleeding (0 day, 1-7 days, > 7 days). We performed among-group comparisons of patient characteristics and surgical aspects, including the extent of surgery. The ratios of male-female and lateral neck dissection were higher in the post-operative bleeding group than in the group without bleeding. In the analysis of patients with postoperative bleeding, grouped according to period between thyroidectomy and reoperation, there was a significant among-group difference in the male-female ratio. The male sex was positively correlated with the reoperation period. Further, the reoperation period was also positively correlated with total thyroidectomy and lateral neck dissection and the operation time showed a significant among-group difference. Our results indicate that the male sex and lateral neck dissection are risk factors for postoperative bleeding after thyroidectomy. Furthermore, male sex, total thyroidectomy, and lateral neck dissection are risk factors for delayed bleeding. Therefore, clinicians should consider these factors for interventions against immediate or delayed bleeding after thyroidectomy.