Objective To investigate the clinical value of intact parathyroid (iPTH) in evaluating the treatment outcome of uremic secondary hyperparathyroidism (SHPT) after ultrasound-guided percutaneous microwave ablation.Methods A retrospective analysis was conducted on 51 cases of uremic SHPT patients who received ultrasound-guided microwave ablation in The Second Affiliated Hospital of Naval Medical University (Second Military Medical University) and Huai'an Tumor Hospital from Jan.2010 to Dec.2018.According to different ablation strategies,patients were divided into complete ablation group (30 cases) and incomplete ablation group (21 cases).Contrast-enhanced ultrasound (CEUS) and isotope localization were performed in 51 patients before ablation.In the incomplete ablation group,the iPTH determination of fine needle aspiration extract was completed for each hyperplast glands before operation.In the complete ablation group,CEUS and isotope examination were performed after operation to confirm whether the hyperplast glands were completely ablated.All patients were followed up for 9 months after surgery to analyze and compare the changes of serum iPTH level in the 2 groups.Results A total of 196 hyperplastic glands in 51 uremic SHPT patients were successfully ablated.The serum iPTH levels at 1 h and 1,3,6,9 months after operation in both groups were significantly lower than those before operation (all P<0.05);at 6 and 9 months after operation,the serum iPTH levels of patients in the incomplete ablation group were significantly higher than those in the complete ablation group (both P<0.001).The serum iPTH levels rebounded in 4 patients in the complete ablation group 6 months after operation,and rebounded in 8 patients in the incomplete ablation group 4 months after operation;the rebound time in the complete ablation group was later than that in the incomplete ablation group,and the rebound amplitude was lower than that in the incomplete ablation group.The percentage of patients whose serum iPTH level rebounded after operation in the complete ablation group was lower than that in the incomplete ablation group (26.7%[8/30]vs 71.4%[15/21],P<0.05).Conclusion There are defects in using iPTH alone as the main indicator of the postoperative efficacy of microwave ablation for uremic SHPT,so a new clinical evaluation system should be established to comprehensively evaluate the effectiveness of this treatment.