Case Control Study of Risk Factors for Occurrence of Postoperative Hematoma After Thyroid Surgery: Ten Year Analysis of 6938 Operations in a Tertiary Center in Serbia

BACKGROUND: Post-thyroidectomy bleeding is rare, but potentially life-threatening complication. Early recognition with immediate intervention is crucial for the management of this complication. Therefore, it is very important to identify possible risk factors of postoperative hemorrhage as well as timing of postoperative hematoma occurrence. METHODS: Retrospective review of 6938 patients undergoing thyroidectomy in a tertiary center in a ten year period (2009-2019) revealed 72 patients with postoperative hemorrhage requiring reoperation. Each patient who developed postoperative hematoma was matched with four control patients that did not develop postoperative hematoma after thyroidectomy. The patients and controls were matched by the date of operation and surgeon performing thyroidectomy. RESULTS: The incidence of postoperative bleeding was 1.04%. On univariate analysis older age, male sex, higher BMI, higher ASA score, preoperative use of anticoagulant therapy, thyroidectomy for retrosternal goiter, larger thyroid specimens, larger dominant nodules, longer operative time, higher postoperative blood pressure and the use of postoperative subcutaneous heparin were identified as risk factors for postoperative bleeding. Sixty-nine patients (95.8%) bled within first 24 h after surgery. CONCLUSION: The rate of postoperative bleeding in our study is consistent with recent literature. Male sex, the use of preoperative anticoagulant therapy, thyroidectomy for retrosternal goiter and the use of postoperative subcutaneous heparin remained statistically significant on multivariate analysis (p < 0.001). When identified, these risk factors may be an obstacle to the outpatient thyroidectomy in our settings.