[Parathyroid hypofunction after total thyroidectomy for differentiated thyroid carcinoma--perspectives after long term observation and treatment].

Hypoparathyroidism remains a serious complication of total thyroidectomy for differentiated thyroid carcinoma (DTC). In Brachytherapy Department 952 patients affected with DTC were followed up in the years 1996-2000. Radical total thyroidectomy was performed in 235 (24.6%) of cases, while the other 717 patients underwent complete rethyroidectomy. The incidence of hypoparathyroidism following radical operation and after complete rethyroidectomy was 15.74% and 23.43%, respectively. In patients operated in our institution, blood for calcium was analyzed daily for five days following the surgery. If calcium level was normal the next measurement was performed 4-5 weeks thereafter. Hypoparathyroidism was diagnosed later in postoperative period in many patients operated elsewhere. Asymptomatic hypocalcemia during the first week after the operation requires oral administration of calcium. If hypocalcemia requiring intravenous calcium supplementation does not resolve in a few days, vitamin 1(OH)D3 is introduced. Vitamin 1(OH)D3 and calcium carbonate play the main role in management of persistent hypocalcemia. In case of marked hypercalciuria thiazid diuretics are instituted. Low-phosphate diet is recommended. The aim of treatment of hypoparathyroidism is to restore normal serum calcium level with calciuria not exceeding 5 mg/kg/24 h, so to avoid hypocalcemic complications as well as vitamin D intoxication.