J. Lee1, M. B. Albuja-Cruz1, C. Burton1, C. D. Raeburn1, R. McIntyre1 1University Of Colorado School Of Medicne,GI, Tumor And Endocrine Surgery,Denver, CO, USA
Introduction:
Intraoperative parathyroid hormone (ioPTH) monitoring is the current gold-standard for intraoperative determination of multi-gland disease (MGD) in patient with primary hyperparathyroidism (PHPT). A prior study found that the risk of persistent disease after minimally invasive parathyroidectomy (MIP) is higher if the weight of the resected gland is ≤ 200mg. The purpose of this study is to determine if the volume and weight of first resected adenoma is a reliable predictor of MGD. This would provide surgeons immediate and inexpensive information to assist with the decision of conversion from a MIP to bilateral neck exploration (BNE).
Methods:
Retrospective review of prospectively collected data of 469 consecutive patients who underwent initial parathyroidectomy for PHPT at a single tertiary medical center from 2010 to June 2015 was performed. Intraoperative parathyroid hormone was used in all cases and intraoperative cure was defined by a >50% drop of the preoperative PTH at 10 minutes and within normal limits. One hundred eighty-five patients met criteria for inclusion in this study. Data was analyzed for patient demographics, operative procedure, first resected adenoma weight and volume, presence of MGD, complications, cure and persistence disease.
Results:
Of the 185 patients, 74% had a single adenoma and 26% had MGD. The mean weight for the single adenoma group was 846 mg compared to 461mg for the MGD group (P< 0.05). A weight of ≥200mg was used as a cutoff to distinguish a single adenoma from MGD (sensitivity 87%, specificity 28%, PPV 76%, NPV 45% and accuracy 71%; P= 0.73).
The mean volume for the single adenoma group was 1.13 compared to 0.5cm3 for the MGD group (P< 0.05). A volume of ≥0.2cm3 was used as cutoff to differentiate a single adenoma from MGD (sensitivity 83%, specificity 35%, PPV 78%, NPV 44% and accuracy 71%; P= 0.82).
Final cure rate for PHPT was achieved in 97% of the patients included in the study. Then median follow up was 25 months.
Conclusions:
The weight and volume of the first resected adenoma are not accurate measures to determine the presence of multigland disease in patients with PHPT, despite significant difference in mean weight and volume between the single adenoma vs. MGD groups. Surgeon judgment and ioPTH remains paramount in the in the operative management of this patient population.