Arterial and venous parathyroid hormone levels in minimally invasive surgery

To establish if venous and arterial parathyroid hormone (PTH) levels are similar during minimal access parathyroid surgery.

Prospective study.

Marshfield Clinic, a large multispecialty tertiary care referral center in central Wisconsin.

All patients who underwent minimally invasive parathyroid surgery over a 10-month period.

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).

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.