Parathyroidectomy: New criteria for evaluating outcome

Following successful parathyroidectomy, subjective improvement in recognize d symptoms and in the overall "well being" of asymptomatic primary hyperpar athyroid patients has been well documented. Because quantitative methods fo r measuring parathyroid hormone (PTH) and normal reference ranges of serum calcium have changed in recent years, a revised biochemical criteria for ev aluating postoperative outcome has become necessary. Two hundred seventy-on e selected patients were followed for an average of 6.3 years after parathy roidectomy. Although 257 patients had serum calcium levels <10.6 mg/dL duri ng the entire follow-up period, 15 per cent of them had elevated intact PTH (iPTH) levels. Fourteen patients had calcium levels greater than or equal to 10.6 mg/dL at some point during follow-up, with nine patients (64%) show ing high iPTH levels and eight (57%) of them developing recurrent hyperpara thyroidism (calcium greater than or equal to 11 mg/dL and iPTH greater than or equal to 68 pg/mL). Of the 14 remaining patients, 5 had hypercalcemia w ith normal iPTH levels. In patients with successfully treated primary hyper parathyroidism, the recommended annual follow-up is: 1) monitor total serum calcium only if serum calcium level is <10.6 . mg/dL, or if serum calcium level is greater than or equal to 10.6 mg/dL; and 2) monitor serum calcium and PTH levels, because these patients have an increased incidence of hyper functioning parathyroid;glands, which may point to late recurrence.