This study focuses on the effectiveness of the Miami criteria in preventing disease persistence and reducing bilateral neck explorations in primary hyperparathyroidism surgery and investigates whether achieving a decrease in intraoperative parathyroid hormone (ioPTH) within the normal range (NR), either alone or in combination with the Miami criteria, leads to improved outcomes.

A retrospective analysis of 380 patient records from two centers was conducted. The ioPTH levels at baseline and 10 minutes after parathyroidectomy were assessed using Miami criterion and criterion of reaching NR. A univariate analysis was carried out and a multivariable logistic regression model was built to identify predictors of persistence. Multicollinearity was checked and the Hosmer and Lemeshow test was used. Odds ratios and 95% confidence intervals were calculated.

Among the patients, 360 were cured, while 20 (5.3%) had persistent disease. Of those with persistence, 11 had a drop >50%, 8 fell within the NR, and 9 and 12 had negative test results, respectively. The multivariate analysis showed a significant association between fall within NR and disease persistence, as well as a significant association with a drop >50%. The combination of both criteria yielded the highest accuracy. Therefore, both tests are considered valid and applicable in clinical practice. Falling within NR helps prevent persistences, while a drop >50% reduces unnecessary bilateral explorations. Combining this criterion provides the best results.

In conclusion, when the ioPTH drop at 10 minutes is <50% but falls within the NR, the intervention can be completed without an increased risk of persistence.