Observations on 334 patients operated on for primary hyperparathyroidism.

334 patients were operated on for PHPT during the years 1956-79. A follow-up study of the material was performed during the years 1980-82 and it included 289 patients. The material was divided into single adenoma (SA) and multiglandular disease (MGD) cases. The initial diagnosis of SA given by the primary operation was later changed in 12 patients (4%) by reoperations performed for persistent or recurrent hypercalcaemia; the follow-up study changed the diagnosis in four patients. The proportion of MGD in the follow-up material was 15.2%. Reoperations were performed in 4% in the SA group and in 29% in the MGD group. The primary results concerning the serum calcium level were good in both SA and MGD groups, but, at the follow-up study 1.6% of the patients in the SA group and 41% of the patients in the MGD group were hypercalcaemic (serum calcium over 2.65 mmol/l). The hypercalcaemia at the follow-up study was, however, slight in general (mean 2.75 +/- 0.09 mmol/l). In the whole material, permanent hypoparathyroidism occurred in 1.2%, permanent unilateral vocal cord paralysis in 0.9% and permanent bilateral vocal cord paralysis in 0.6%. Operative mortality was 0.9%. The "conservative" strategy used in the whole material gave good results in SA patients but considerably worse results in MGD patients. Accordingly, MGD patients should be operated more "radically".