Total Thyroidectomy is Associated with Increased Prevalence of Permanent Hypoparathyroidism

BACKGROUND: Thyroid disorders are very common in adults. Despite advances in conservative management, surgery remains a treatment modality of choice in many cases. The mortality and morbidity of thyroidectomy are low, but long-term postoperative hypoparathyroidism (HPT) remains a prominent complication of the procedure. The aim of this study was to assess the incidence of permanent HPT and identify the risk factors for this complication in a cohort of post-thyroidectomy patients followed at a District Endocrine Clinic. MATERIAL AND METHODS: This was a retrospective analysis of 401 patients followed up at a Regional/District Endocrine Clinic, who had undergone thyroid surgery in the years 1993-2011. The percentage of patients with permanent (>12 months) HPT was the primary endpoint of the study. The statistically analyzed data of patients with permanent HPT versus the remaining patients free from postoperative complications included their demographic data, indications for surgical treatment of their thyroid disorder, and extent of the thyroid resection. The risk factors for postoperative hypoparathyroidism were assessed using logistic regression analysis. RESULTS: Permanent HPT following surgery on the thyroid gland occurred in 8.5% of the patients. It was more frequent following total thyroidectomy (20.2%) than near-total thyroidectomy (6.7%) or subtotal thyroidectomy (4.2%); p<0.0001. A multivariate statistical regression analysis demonstrated that primary total thyroidectomy was a significant risk factor for permanent HPT (OR 6.5; 95% CI: 2.9-14.4; p<0.0001). CONCLUSIONS: Total thyroidectomy was associated with increased prevalence of permanent hypoparathyroidism when compared to less extensive thyroid resection modes in patients with benign thyroid diseases.