Use of intraoperative parathyroid hormone measurement does not improve success of bilateral neck exploration for hyperparathyroidism

Hypothesis: Use of intraoperative measurement of intact parathyroid hormone (iPTH) to confirm complete excision of hyperfunctioning parathyroid tissue does not improve overall operative success rates. Design: Case series of patients undergoing parathyroidectomy with or withou t intraoperative iPTH measurement. Setting: University teaching hospital. Patients and Interventions: Fifty patients undergoing parathyroidectomy bef ore our institution of intraoperative iPTH sampling in March 1999 (group 1) were compared with 50 patients undergoing parathyroidectomy after this tec hnique was adopted (group 2). Overall, 100 patients underwent operation bet ween December 1996 and May 2000. Serum calcium and iPTH levels were measure d at 1- and 3-month intervals. Intraoperative frozen sections and operative times were also analyzed. Results: Mean preoperative calcium levels were 2.85 and 2.82 mmol/L (11.4 a nd 11.3 mg/dL) in groups 1 and 2, respectively. One-month postoperative cal cium values were identical in both groups at 2.35 mmol/L (9.4 mg/dL) (group 1 SD=0.18 [0.74], group, 2 SD = 0.20 [0.82]). At 1 month, all but 1 patien t in group 1 had normalized calcium values (2% failure rate),while 3 patien ts in group 2 (6%) remained hypercalcemic. All 3 patients in group 2 had in traoperative iPTH levels that returned to normal. There was a significant d ifference in the number of intraoperative frozen sections between groups, w ith a mean (SD) of 3.4 (1.7) in group 1 and 2.0 (1.6) in group 2 (P < .01). There was no significant difference in operative times between groups. Conclusions: Use of intraoperative iPTH sampling did not significantly affe ct the overall success of parathyroidectomy, as determined by postoperative normocalcemia. There was, however, a significant decrease in the number of frozen sections sent at operation.