Objective To establish if venous and arterial parathyroid hormone (PTH) levels are similar during minimal access parathyroid surgery.
Design Prospective study.
Setting Marshfield Clinic, a large multispecialty tertiary care referral center in central Wisconsin.
Patients All patients who underwent minimally invasive parathyroid surgery over a 10-month period.
Results Fifteen consecutive patients were evaluated. There were 11 women and 4 men, with an average age of 65 years. All patients underwent a preoperative technetium Tc 99m sestamibi scan, with 11 localizing to the site of a probable adenoma. Mean ionized calcium levels were 5.95 mg/dL (1.49 mmol/L) preoperatively and 4.84 mg/dL (1.21 mmol/L) postoperatively. Of 13 patients undergoing both arterial and venous sampling, mean baseline venous PTH level was 221 pg/mL and 37 pg/mL at 10 minutes after excision of suspected adenoma (83% decline). Mean baseline arterial PTH level was 247 pg/mL and 38 pg/mL at 10 minutes after excision (84% decline). Using the Wilcoxon signed rank test, there was no significant difference in the arterial vs venous levels at baseline (P = .70) or 10 minutes (P = .48).
Conclusions Intraoperative PTH levels during minimal access parathyroid surgery are similar for venous and arterial samples. Blood samples for PTH level monitoring can be obtained using a temporary indwelling arterial line.
