Endocrine Abstracts

Introduction: Hypoparathyroidism (hypoPT) is the most frequent complication after thyroid surgery, usually as transient hypocalcaemia. Permanent parathyroid lesion is less frequent, but it can extend hospital stay and complicate postoperative management. Several preoperative factors predicting the development of hypoPT have been identified, including advanced age, hyperthyroidism, surgical experience and others. We evaluate the role of some potentially predictive factors in our recent surgical series.

Description of methods/design: We analyze retrospectively 649 patients with total thyroidectomy from 2005 to 2011, followed up more than 1 year after surgery. Permanent hypoPT (PhypoPT) is defined by (iPTH) <15 pg/ml without treatment more than 1 year after surgery. (iPTH) between 5 and 15 pg/ml were defined as partial deficiency, whereas <5 pg/ml was considered total deficiency. Cases with spontaneous recovering of parathyroid function after a period of (PTHi) <15 were named as transient hypoPT (ThypoPT). We consider age, thyroid size (by weight), sex, presence of hyperthyroidism, central dissection and cause of surgery as variables in our study.

Results: 449 patients didn’t show postoperative hypoPT (70.6%), 151ThypoPT (23.3%; 87 of them normalized at 1st month) and 49 (7.55%) PhypoPT, 27 of them (4.1%) total deficiency. Significant differences among the three groups were found in three variables: thyroid weight, lower in PhypoPT (mean (S.D.): 53.5 (57.8) g vs 69.9 (46.8) and 63.3 (58.6) g in non-hypoPT and ThypoPT; P:0.027); fulfillment of central dissection, carrying an OR for hypoPT of 5.06 (CI: 3.10–8.28), and OR for PhypoPT vs ThypoPT: 3.08 (CI: 1.99–4.77)); and surgery reason (cytology/biopsy vs others; OR for HypoPT: 1.72 (CI: 1.22–2.41), and OR for PHyPT vs THyPT: 1.38 (CI: 1.04–1.84)). Neither age nor prevalence of hyperthyroidism showed differences among three groups as well as sex distribution.

Conclusion: Parathyroid damage is more prevalent in total thyroidectomy when it is indicated for malignant or suspicious cytology or biopsy, particularly when it is completed with dissection of central cervical compartment in smaller glands. Our series finds that gender, age or hyperthyroidism haven’t got influence in the risk of postoperative hypoPT.