title: Endoscopic cryosurgery of the thyroid and parathyroid.
abstract: In this study we looked at the efficacy of cryosurgery for thyroid and parathyroid tissue ablation in the porcine model. An endoscopic neck approach was successfully used in six 25 kg pigs. T4, free T4 and calcium serum levels were measured pre- and post-operatively. Gross and histologic examination of the glands and surrounding tissue were performed on postoperative Day 40. Postoperative T4, free T4 and calcium levels were not significantly different from preoperative values. Gross examination of the thyroid showed scar tissue in the region that underwent cryosurgery. Parathyroid that was frozen was replaced by scar tissue. Histologic examination of the glands confirmed the gross findings. Trachea, vagus nerve and carotid artery were also resected, and no changes were noted on histological examination. There was no damage to the surrounding tissues after cryosurgery. Directed cryosurgery of the thyroid and parathyroid is safe and feasible in this model.