Risk factors for surgical failure in patients undergoing surgery for primary hyperparathyroidism

Primary hyperparathyroidism is the third most common endocrine disease. The aim of our study was to determine long-term outcomes and risk factors for persistence in patients undergoing parathyroidectomy for primary hyperparathyroidism.

Retrospective study including patients undergoing parathyroidectomy between 2009-2019. Cure was defined as reestablishment of normal calcium homeostasis lasting a minimum of 6 months. Persistence was defined by ongoing hypercalcemia more than 6 months after surgery. Recurrent PHTP was defined by recurrence of hypercalcemia after a normocalcemic interval at more than 6 months after surgery. A more detailed analysis was performed on patients with normocalcemia and persistently elevated PTH levels after surgery. Variables independently related to persistence were analyzed by multivariate analysis.

We included 212 patients. Mean age was 59 years and 83% were women. Cure was observed in 204 patients (96.2%), persistence in 8 (3.8%) and recurrence in 3 (1.4%). Four patients (1.9%) presented normocalcemia and persistently elevated PTH after surgery. All presented parathyroid pathology (2 adenomas and 2 hyperplasia). In follow-up we observed that adenoma subgroup presented one patient with CKD and one with vitamin D deficiency while in the hyperplasia subgroup two patients presented CKD. Persistence was independently associated with hyperplasia (Odds ratio = 12.6, IC95% = 1.28-124, p = 0.030) and normal parathyroid tissue (Odds ratio = 188, IC95% = 9.33-379, p = 0.001) on histopathological report.

Primary hyperparathyroidism is a safe procedure in terms of morbidity and long-term outcomes. Hyperplasia and normal parathyroid tissue on histopathological report are risk factors for persistence. An interdisciplinary diagnostic and therapeutic approach is required to prevent persistence.