Effect of parathyroidectomy in patients with hyperparathyroidism, Zollinger-Ellison syndrome, and multiple endocrine neoplasia type I: a prospective study.

This study evaluates prospectively the effect of parathyroidectomy on basal acid output (BAO), maximal acid output (MAO), fasting serum gastrin, secretin-stimulated serum gastrin, and sensitivity to antisecretory medication in 10 consecutive patients with primary hyperparathyroidism (PHP), Zollinger-Ellison syndrome (ZES), and multiple endocrine neoplasia type I (MEN-I). After parathyroidectomy, 9 of 10 patients remained normocalcemic, and each had a lower BAO; 6 of 9 no longer had gastric acid hypersecretion (less than 15 mEq/hr). Seven of 9 normocalcemic patients had a lower MAO, and a decrease in fasting serum gastrin. Two patients showed no evidence of ZES, a normal BAO, normal fasting serum gastrin concentration, and a negative secretin response after parathyroidectomy. Parathyroidectomy also reduced the dose of histamine H2-receptor antagonist required to control gastric acid secretion in 60% of patients. After successful parathyroidectomy three patients were studied for drug sensitivity, and each had greater acid inhibition with a given dose of histamine H2-receptor antagonist than preoperatively. One patient remained hypercalcemic after surgery and had no change in BAO, MAO, or gastrin. All patients with postoperative normocalcemia will have a lower BAO, 80% a lower MAO, 80% a decreased fasting serum gastrin, and 33% a negative secretin test. Antisecretory medication dose can be reduced because patients have reduced BAO and increased sensitivity to histamine H2-receptor antagonist. The study supports parathyroidectomy as the initial surgical procedure of choice in patients with PHP, ZES, and MEN-I.