MINIMALLY INVASIVE PARATHYROIDECTOMY FACILITATED BY INTRAOPERATIVE NUCLEAR MAPPING

Background. The inability to predict the location and number of diseas ed parathyroid glands has precluded the wide acceptance of unilateral neck exploration for primary hyperparathyroidism. We used intraoperati ve nuclear mapping in patients identified by sestamibi scanning to hav e a single adenoma in hopes of minimizing operative intervention whit maintaining the efficacy of a full exploration. Methods. Fifteen conse cutive patients with primary hyperparathyroidism underwent technetium 99m-labeled sestamibi scanning 3.0 +/- 0.1 hours before operation. Pla cement of the initial 2.0 cm incision and all dissection were guided b y quantitative gamma counting in four neck quadrants with an 11 mm Neo probe. Ex vivo radioactivity was determined for parathyroid glands, fa t, and lymph nodes. Potential radiation hazards were assessed. Results . Intraoperative nuclear mapping discriminated between 14 solitary ade nomas and one patient with four-gland hyperplasia that was not Predict ed on preoperative sestamibi scanning: Removal of the adenoma resulted in a decline in radioactivity in that quadrant (p < 0.001) and the en tire neck (p < 0.05), with equalization of all neck quadrants. Ex vivo counts always identified parathyroid tissue (p < 0.0001 versus fat an d lymph node). Adenomas were located in 19 +/- 1.7 minutes through a 2 .3 +/- 0.1 cm incision. No significant radiation hazard existed, and n o special handling of the specimen was required (0.06 +/- 0.01 mR/hr). Conclusions. Intraoperative nuclear mapping complements sestamibi sca nning to help distinguish single-gland from multigland disease. This t echnique allows for a minimally invasive operation under local anesthe sia in a true outpatient setting.