Surgery for primary hyperparathyroidism: experience with 500 consecutive cases and evaluation of the role of surgery in the asymptomatic patient.

A group of 500 patients with a presumptive diagnosis of primary hyperparathyroidism (HPT) was operated upon at the Mayo Clinic between September 1974 and May 1980 using a standardized operative strategy. Clinical profiles, biochemical data, operative findings and pathological changes are reviewed. Of the 500 patients, 461 (92.2 per cent) were cured after primary cervical exploration. One patient died during the postoperative period, 1 had a permanent unilateral vocal cord paralysis and 10 (2 per cent) had protracted hypoparathyroidism. Owing to the continuing controversy regarding the appropriate therapeutic management of asymptomatic, uncomplicated and mild ('biochemical') primary HPT, we further evaluated this surgical experience by comparing the results of operation in two groups of patients: those with 'biochemical' HPT (serum calcium less than 11 mg/dl) and those with 'non-biochemical' HPT (symptomatic or complicated disease or serum calcium greater than 11 mg/dl). The cure rate in each patient group was greater than 90 per cent. A statistically significant increase in the incidence of negative cervical exploration (4 normal parathyroid glands identified and biopsied) was noted in the 'biochemical' group. However, parathyroid disease was found at operation in 92 per cent of these patients. We conclude that cervical exploration in all patients with primary HPT, including those with 'biochemical' disease only, is safe and that such an aggressive management policy is justified.