Sonographically guided fine needle aspiration with rapid parathyroid hormone assay.

BACKGROUND: Persistent or recurrent primary hyperparathyroidism (1 degrees HPTH) is ideally treated with limited dissection, based on accurate localization, to minimize operative risks. To accurately localize parathyroid tissue, we employed ultrasound-guided fine needle aspiration (US FNA) with an on-site rapid parathyroid hormone (PTH) assay to confirm localization. METHODS: Of the 272 patients evaluated for 1 degrees HPTH, 34 had persistent or recurrent disease. Standard localization was equivocal in 12, who were referred for US FNA. Suspicious tissue was identified on US and FNA was performed. Analysis with a rapid PTH assay provided on-site result within 12 min. Patients were monitored clinically, and then discharged after observation. RESULTS: Twelve patients were referred for US FNA; eight were female. Ten patients had persistent disease, one had recurrent, and one had 1 degrees HPTH following thyroidectomy. Two of the 12 were excluded due to negative ultrasound examination. Of the remaining ten, positive aspirates were found in nine, and seven proceeded to surgery. In six patients there was 100% correlation between sonographic and operative findings. The remaining patient had no identifiable adenoma, but PTH normalized after arterial ligation. All patients received a limited directed surgical approach, employing cervical block anesthesia in three. Four were discharged on the day of surgery and all were cured. There was one infectious complication of US FNA. CONCLUSIONS: The use of rapid PTH assay can be effectively utilized for localization of parathyroid tissue in remedial parathyroid surgery. Confirmation of localization markedly improves subsequent surgery and allows selective use of minimally invasive techniques.

Rapid parathyroid hormone analysis during venous localization.

OBJECTIVE: To determine the usefulness of the rapid parathyroid hormone (PTH) assay during venous localization for primary hyperparathyroidism (1 degrees HPTH). SUMMARY BACKGROUND DATA: Remedial exploration for persistent 1 degrees HPTH poses a significant challenge when noninvasive preoperative localization studies are negative. Based on experience with the intraoperative rapid PTH assay, this technique was extrapolated to the interventional radiology suite and generated near real-time data for the interventional radiologist employing on-site hormone analysis, with a 12-minute turnaround time from blood sampling to assay result. METHODS: Between November 1997 and July 2002, 446 patients with 1 degrees HPTH were referred for treatment. Of these, 56 (12.5%) represented remedial patients who had each undergone one or more previous cervical explorations. Noninvasive imaging studies were positive for or suggestive of localized disease in 49/56 (87.5%) of these patients, who therefore proceeded directly to surgical exploration. Seven patients with persistent 1 degrees HPTH and negative noninvasive studies underwent selective venous sampling employing a rapid PTH assay in the interventional suite. RESULTS: Venous localization demonstrated an apparent PTH gradient in six of the seven patients. In three, a subtle gradient demonstrated in near real-time prompted additional sampling, which confirmed an unequivocal hormone gradient. In an additional case, the absence of a gradient on initial sampling prompted further sampling, which was positive. All of the patients were explored, and in five of the six patients with a positive PTH gradient, a parathyroid adenoma (mean weight 636 +/- 196 mg) was resected from a location predicted by venous localization. In the sixth patient with a positive gradient, parathyroid tissue was not identified; however, there was a significant fall in the intraoperative PTH values, and immediate postoperative and follow-up laboratory data at 1 month are indicative of a cure. In the one patient with negative localization, abnormal parathyroid tissue could not be located during surgical exploration. CONCLUSIONS: The rapid PTH assay is a major adjunct for obtaining informative venous localization in patients with persistent 1 degrees HPTH. This information is extremely helpful to the surgeon in this challenging group of patients and resulted in a 100% cure rate when a venous gradient was demonstrated. The authors now employ this technique routinely in remedial patients with negative noninvasive imaging studies.