Outcome of subtotal parathyroidectomy for surgical treatment of hyperparathyroidism after renal transplantation

Financial support: None. Conflicts of interest: No conflicts of interest declared concerning the publication of this article. Submitted: February 06, 2019. Accepted: November 17, 2019. The study was carried out at Departamento de Otorrinolaringologia e Cirurgia de Cabeça e Pescoço, Universidade Federal de São Paulo (UNIFESP), São Paulo, SP, Brasil. This study was presented at the Congresso Brasileiro de Cirurgia de Cabeça e Pescoço – August 2019 Gramado, RS. Abstract Introduction: Parathyroidectomy (PTX) is one of the forms to treat hyperparathyroidism (HPT) after renal transplantation (RT), but choosing the appropriate surgical technique is controversial. The option for more conservative surgeries, such as subtotal parathyroidectomy (STPX), has been expanding owing to the lower risk of definitive HPT and its effectiveness in controlling hypercalcemia. Objective: To evaluate the efficacy of STPX as a definitive treatment for hyperparathyroidism after renal transplantation (HPTRT) and determine whether there is a relationship between percentage intraoperative parathyroid hormone (ioPTH) decay levels and parathyroid hormone (PTH) values on the first postoperative day and surgical success. Methods: This retrospective study analyzed the medical records of prospectively followed patients diagnosed with HPT-RT submitted to STPX in two tertiary hospitals (Brazilian Unified Health System SUS) for two years. Patients were allocated in two groups according to operative success (SG normalization of ionized calcium (iCa) and PTH six months after surgery) or operative failure (FG persistence of high iCa and PTH). The percentage ioPTH decay levels and the postoperative PTH absolute values on the first postoperative day were evaluated in both groups. Results: Of the total sample of 31 patients, surgical treatment was successful in 27 cases (87%). No statistically significant differences were observed between the groups for the percentage ioPTH decay levels (SG = 71.51% vs. FG = 70.4%), as well as for the PTH absolute values on the first postoperative day (SG = 52.69pg/ mL vs. FG = 54.55pg/mL). Conclusion: Subtotal parathyroidectomy is an effective and safe procedure for treating HPT-RT; however, the use of PTH levels remains subjective and cannot be considered as a predictor of surgical success.