Complications After Thyroid Surgery

Abstract: Background: Thyroidectomy is a common surgical procedure performed worldwide. Postoperative complications can be life-threatening. Many efforts have been made during the last century to reduce the burden of postoperative complications, with remarkable achievements. However, there are still many patients suffering.Aims: the main aims of the first three studies were to understand risk factors for infection, postoperative bleeding, and hypocalcaemia after thyroidectomy. The fourth study aimed to understand the life expectancy in elderly patients (80 or older) undergoing thyroid surgery for benign thyroid disorders.Methods: The Scandinavian Quality Register for Thyroid, Parathyroid, and Adrenal Surgery (SQRTPA), a nationwide database for thyroid surgery, was used for patient data collection. Studies I and II used a nested case-control design, and attending surgeons were asked to add further data on cases and controls. For studies III and IV, data from the SQRTPA were used along with data from the National Health Care Registers; the Swedish Prescribed Drug Register, and the Swedish Cause of Death Register. Results: In study I, multiple regression analysis showed that risk factors for postoperative bleeding were male gender, high age, and use of a drain, with odds ratios (ORs) and corresponding 95 % confidence intervals (95 % CIs) of 2.2 (1.6-3.0), 3.6(1.8-7.4), and 1.7(1.1-2.7) respectively. In study II, adjusted multiple regression showed that risk factors for postoperative surgical site infection were lymph node dissection and use of a drain, with OR (95 % CI) 3.2(1.3-7.8) and 1.8(1.04-3.2) respectively. In study III, central lymph node dissection was an independent risk factor for postoperative permanent hypoparathyroidism in patients operated for papillary thyroid cancer with OR (95 % CI) of 3.7(1.5-9.6). In patients operated with total thyroidectomy and central lymph node dissection, node-negativity was a risk factor for permanent hypoparathyroidism and had an OR (95 % CI) of 3.1(1.3-7.2). In study IV, apart from age, no other risk factors were found for death after thyroid surgery for benign thyroid disease. The median (IQR) follow-up time was 4.5 (2.9-7.2) years, and the median (IQR) survival time was 8.0 (4.1-12.5) years. The standardised mortality ratio was 0.76 for women and 0.67 for men.Conclusions: In thyroid surgery, high age, male gender, and the use of a drain are independent risk factors for postoperative bleeding. Lymph node dissection and the use of a drain are independent risk factors for surgical site infection. Central lymph node dissection is an independent risk factor for postoperative permanent hypoparathyroidism in patients operated for papillary thyroid cancer; those with negative lymph nodes have a higher risk. Mortality in patients aged 80 years or older undergoing thyroid surgery for benign thyroid disease is lower than the general population, with no specific risk factors apart from age.