title: Parathyroidectomies using intraoperative parathormone monitoring: when should we stop measuring intraoperative parathormone levels?
abstract: Intraoperative parathyroid hormone monitoring (IOPM), in use for the last 15 years, has facilitated focused parathyroidectomy. We undertook this study to determine if a drop in IOPT hormone levels below 50 per cent of baseline were sufficient to terminate the procedure. We conducted  a retrospective chart review (January 2007 to September 2010) of 104 patients who underwent initial parathyroidectomies with IOPM by general surgeons for primary hyperparathyroidism. Patients were followed up for serum calcium levels (range, 6 to 48 months). The number of specimens excised  was significantly decreased when IOPT hormone levels dropped to greater than 50 per cent and came within the normal range earlier. Moreover, for single-gland parathyroid adenomas, once the parathyroid hormone values dropped to less than 50 per cent in the 5-minute sample, they continued to  decrease in the subsequent samples. In 23 cases requiring further exploration, the parathyroid hormone values had already decreased to greater than 50 per cent in 14 cases but had not normalized (reference range, 8 to 74), leading to additional exploration. However, subsequent pathologic analysis  showed that the initial gland removed was the adenoma in all these cases. A drop in the initial 5-minute parathyroid hormone value to less than 50 per cent of the baseline should serve as sufficient evidence to terminate the procedure. This would translate into significant laboratory and personnel  cost savings over time. However, this should be carefully correlated with preoperative ultrasound/sestamibi findings.
authors.affiliation: Department of Surgery, Providence Hospitals and Medical Centers, Southfield, Michigan, USA. adi_dec17@yahoo.com
authors.forename: Aditya
authors.initials: A
authors.lastname: Gupta
authors.forename: Amruta
authors.initials: A
authors.lastname: Unawane
authors.forename: Gokulakkrishna
authors.initials: G
authors.lastname: Subhas
authors.forename: Barry R
authors.initials: BR
authors.lastname: Herschman
authors.forename: Sumet
authors.initials: S
authors.lastname: Silapaswan
authors.forename: Ramachandra
authors.initials: R
authors.lastname: Kolachalam
authors.forename: William
authors.initials: W
authors.lastname: Kestenberg
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Ferguson
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Jacobs
authors.forename: Vijay K
authors.initials: VK
authors.lastname: Mittal
mesh_terms: D000236:Adenoma / Q000601:surgery; D015415:Biomarkers / Q000097:blood; D002118:Calcium / Q000097:blood; D005260:Female; D006801:Humans; D006961:Hyperparathyroidism / Q000000981:diagnostic imaging / Q000601:surgery*; D007432:Intraoperative Period; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood*; D016105:Parathyroidectomy; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D014463:Ultrasonography
chemical_list: D015415:Biomarkers; D010281:Parathyroid Hormone; D002118:Calcium