Causes of failure in operations for hyperparathyroidism.

After a mean follow-up period of 6.1 years, a series of 862 patients who had undergone surgery for suspected hyperparathyroidism were evaluated to determine the reasons treatment failed. Incorrect diagnosis was found to be the cause of failure in 27 cases (3%). In 89 patients who required reoperation to achieve euparathyroidism, the three major reasons for failure were inexperience with the surgical procedure (n = 37), abnormal localization (n = 36), and multiglandular disease (n = 39). In patients with monoglandular involvement, the disease never recurred. However, of the 41 patients with more than one enlarged parathyroid gland, 20 had persistent disease and 21 others had recurrent disease with a normocalcemic interval of 1.2 to 17 years. In general, recurrent hyperparathyroidism occurs more frequently than is usually realized and thus patients with multiglandular involvement require very long follow-up periods. Persistent monoglandular disease is largely avoidable.