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

INTRODUCTION: 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. METHODS: 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. RESULTS: 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. CONCLUSIóN: 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.