A prospective evaluation of the effect of sample collection site on intraoperative parathormone monitoring during parathyroidectomy.

BACKGROUND: Sample collection site may affect the dynamics of intraoperative parathyroid hormone monitoring (IPM) and influence surgical decisions. METHODS: We prospectively studied 45 patients undergoing parathyroidectomy for primary hyperparathyroidism. The IPM cure criterion was a decrease in peripheral vein (PV) parathyroid hormone (PTH) of >50% at 10 minutes after gland excision. PTH samples were collected simultaneously from PV and central vein (CV) and compared for PTH decay, the incidence of >50% PTH decay, and the incidence of normal PTH values after gland excision. RESULTS: Mean PTH levels were significantly higher from the CV before and after gland excision. Mean PTH decay 10 minutes after gland excision was 89% PV versus 88% CV, resulting in mean PTH levels of 27 +/- 23 and 39 +/- 35 pg/mL, respectively (P < .0001). At 5 minutes, >50% decay in PTH was present in 98% PV versus 88% CV samples. By 10 minutes, the incidence of >50% PTH decay was equivalent (98%). This yielded normal range PTH levels from the PV versus CV in 90% versus 76% of patients at 5 minutes, 96% versus 89% at 10 minutes, and 95% versus 81% at 20 minutes. Of 45 patients, 44 (98%) are normocalcemic at a mean follow-up of 6.3 months. IPM predicted the single operative failure. CONCLUSIONS: CV sampling produces significantly higher PTH levels. Surgeons sampling from a PV may observe a >50% decrease in PTH and normal range PTH values starting 5 minutes after gland excision. Surgeons who sample from the CV and require normalization of PTH levels may have to wait longer and/or continue potentially unnecessary neck exploration.

Does homocysteine contribute to bone disease in hyperparathyroidism?

BACKGROUND: Osteoporosis is a complication of hyperparathyroidism (HPT). Hyperhomocysteinemia (HHCy) is an independent risk factor for osteoporotic fractures. We hypothesize that HHCy correlates with bone disease in HPT. METHODS: A prospectively collected database of 250 patients treated for HPT was reviewed. Patients were categorized into 3 groups: group I, normal renal function; group 2, mild renal insufficiency; and group 3, secondary HPT with end-stage renal disease on dialysis. Serum homocysteine levels, markers of bone metabolism, and bone density studies were examined. RESULTS: The prevalence of HHCy in group 1 (208 patients) was 5%, in group 2 (23 patients), 82%, and in group 3 (19 patients), 78%. Mean (+/-SD) preoperative homocysteinemia (HCy) levels in groups 1, 2, and 3 were 9.3 +/- 4.0, 20 +/- 10.2, and 20.6 +/- 12.3 micromol/L, respectively. Elevated serum markers of bone metabolism increased significantly with decreasing renal function. CONCLUSIONS: Prevalence of HHCy is low in HPT patients with normal renal function. It is significantly greater in those with dialysis-independent and -dependent renal insufficiency. HHCy correlates with other serum markers of bone metabolism in HPT and may be useful for monitoring progression or improvement.

Short-term outcomes of parathyroidectomy in patients with or without 25-hydroxy vitamin D insufficiency.

BACKGROUND: 25-OH Vitamin D (VitD) plays a role in serum calcium (Ca) and parathyroid hormone (PTH) homeostasis. VitD insufficiency in patients with primary hyperparathyroidism (HPT) may be associated with greater disease severity and a higher incidence of multi-gland disease and postoperative normocalcemic PTH elevation. MATERIALS AND METHODS: One hundred ten patients with HPT undergoing parathyroidectomy had preoperative VitD levels as follows: levels were insufficient (< or =20 ng/mL) in 55 patients (group 1) and sufficient (>20 ng/mL) in 55 patients (group 2). All patients had preoperative localizing sestamibi scans and/or ultrasounds and postoperative serum Ca and PTH levels. A focused approach was performed when possible, and intraoperative PTH monitoring (IPM) was used in all patients. RESULTS: Patients with VitD insufficiency had significantly higher preoperative Ca (11.3 +/- 1.2 versus 10.8 +/- 0.9 mg/dL, P = 0.012) and PTH levels (204 +/- 138 versus 156 +/- 179 pg/mL; P = 0.006) as well as higher bone specific alkaline phosphatase (P = 0.006). Localization studies were similar. IPM levels were significantly higher in group 1 at all time intervals. Both groups were similar in operative time, conversions to bilateral explorations, number of glands removed, and number of frozen sections. The glands in group 1 were larger (1757 versus 524 g; P = 0.005). Postoperative Ca levels, PTH levels, rates of eucalcemia, and rates of eucalcemic PTH elevation were all similar. CONCLUSION: Patients with HPT and VitD insufficiency may have significantly more severe disease based on preoperative serum Ca and PTH levels, bone markers, and gland size. IPM levels in these patients are higher but can be used to predict postoperative eucalcemia, an outcome which appears be independent of VitD status.