Unilateral exploration based upon preoperative imaging has become increasingly applied in the management of patients with primary hyperparathyroidism. Unilateral surgical exploration purportedly has high rates of disease control, limited morbidity, and shortened operative time. Unfortunately, significant cohorts of patients with primary hyperparathyroidism are unable to have abnormal glands localized on preoperative imaging evaluation.
Aim: The aim of our study was to evaluate the efficacy of Tc(99m) sestamibi preoperative imaging, intraoperative Tc(99m) sestamibi with gamma probe, and intraoperative parathyroid hormone (IOPTH) assessment in a large cohort of patients with primary hyperparathyroidism.
Results: A total of 427 patients were prospectively evaluated who were deemed surgical candidates for the treatment of primary hyperparathyroidism. Of these patients, 240 (56%) presented with positive Tc(99m) sestamibi imaging. Another 105 (25%) presented with equivocal Tc(99m) sestamibi imaging. Finally, 82 (19%) presented with negative Tc(99m) sestamibi imaging. Intraoperative rapid assessment of parathyroid hormone was performed at the time of surgical exploration in all patients with negative and equivocal preoperative imaging. All 240 patients with positive preoperative imaging underwent unilateral surgical exploration utilizing intraoperative Tc(99m) sestamibi with gamma probe. The most common finding in the positive Tc(99m) sestamibi scan group was single adenoma in 235 (98%). Normocalcemia was achieved in 233 (97%) of these patients, although in 25 (10%) this was normocalcemia with a persistent elevation in parathyroid hormone (PTH). The most common surgical finding in the equivocal Tc(99m) sestamibi scan group was single adenoma in 85 (81%). Additionally 85 (81%) of these equivocal patients were able to undergo unilateral exploration limited by IOPTH assessment. Normocalcemia was achieved in 101/105 (96%) of patients; although, 10 patients were normocalcemic with persistently elevated PTH and 2 patients had normocalcemia with low PTH. All patients with negative Tc(99m) sestamibi scan underwent bilateral cervical exploration plus IOPTH; 52/82 (63%) were found to have a single adenoma which was the most common surgical finding. Normocalcemia was achieved in 77/82 (94%) of the negative Tc(99m) sestamibi cohort; although 5 patients had normocalcemia with persistently elevated PTH and 2 had normocalcemia with low PTH. Only 3 (0.7%) overall recurrent laryngeal nerve injuries were encountered, and only 1 (0.2%) was permanent. Wound complication rates are reported in detail and were low and comparable for all three Tc(99m) sestamibi imaging based cohorts.
Conclusions: Tc(99m) sestamibi preoperative imaging, intraoperative Tc(99m) sestamibi with gamma probe, IOPTH, and combinations of these strategies allow for excellent opportunities for targeted excision of pathologic parathyroid tissue with the least dissection necessary while achieving excellent long-term calcium control and low rates of complication.