The traditional answer is 1 criterion, with 4-gland exploration finding a single adenoma and 3 normal glands. But over the last 20 to 30 years, there has been an increasing impetus to limit surgical exploration, fueled by a series of innovations. These methods to identify a single adenoma and to facilitate intraoperative decision making are MIBI imaging, high-resolution US, and rapid IOPTH. MIBI imaging is widely used, but IOPTH is not available at every institution, not all imaging systems are enhanced with single-photon emission computed tomography, and all ultrasonographers are not created equal, nor are all necks created equal in the eyes of the ultrasonographer.
Coe NPW. How Many Criteria Does It Take to Remove a Single Parathyroid Gland?Comment on “Critical Role of Identification of the Second Gland During Unilateral Parathyroid Surgery”. Arch Surg. 2011;146(5):516. doi:10.1001/archsurg.2011.77