Clinical characteristics and outcomes of patients operated for primary hyperparathyroidism at Tampere University Hospital in 2017-2018.

Background and objective: Studies on the outcomes of parathyroid surgery are scarce. The aim was to report the outcomes and to study the association between pre- and peri-operative information with the outcomes of patients operated for primary hyperparathyroidism.

Methods: This was a retrospective, descriptive study with unselected patients treated surgically for primary hyperparathyroidism from a catchment population of 704,500 in Finland. Data were acquired from the electronic hospital registers based on parathyroid surgery procedure codes between 1 January 2017 and 31 December 2018. Preoperative data, surgical data, preoperative and postoperative laboratory values, histopathological findings, and postoperative clinical data were recorded.

Results: During the 2-year study period, 149 patients with primary hyperparathyroidism were treated surgically with a 97% remission rate. Surgical complications included postoperative bleeding in two patients (1%) and vocal cord paralysis in one patient (0.6%). No postoperative infections were reported. Three patients (2%) developed postoperative hypoparathyroidism necessitating the use of alfacalcidol more than 1 month after surgery. Ionized calcium measured 0-1 days after surgery was not statistically significantly associated with remission or postoperative hypoparathyroidism. Serum parathyroid hormone (PTH) assessed 0-1 days postoperatively was associated with persistent disease, but not with postoperative hypoparathyroidism. The histopathological diagnosis was adenoma or hyperplasia in 112 patients (75%), atypical adenoma in 28 patients (19%), and carcinoma in five patients (3%). Patients with parathyroid carcinoma had higher preoperative ionized calcium and PTH values than those with adenoma or hyperplasia.

Conclusions: Most patients who were operated due to primary hyperparathyroidism achieved normocalcemia after surgery, and the frequency of complications was low. Ionized calcium taken 0-1 days after surgery was not associated with remission of hyperparathyroidism or postoperative hypoparathyroidism. High postoperative serum PTH predicted persistent disease.