Inadvertent parathyroid excision during thyroid surgery

Background: Thyroidectomy is a commonly performed operation for the treatment of thyroid disease. Inadvertent removal of parathyroid glands is a recognised complication of this operation and may have consequences on the longterm regulation of calcium homeostasis post-operatively. We aimed to establish the incidence of parathyroid gland excision during surgery for thyroid disease and whether there was an effect on calcium control in patients in whom inadvertent parathyroidectomy had occurred. Methods: A retrospective review of thyroid operations at our hospital from 2001 to 2004 was carried out, reviewing pathology reports to identify specimens which included parathyroid tissue. Post-operative calcium levels were reviewed in these patients. Results: Over three years, 126 thyroid operations were performed; 96 total thyroid lobectomies and 30 total thyroidectomies. Of these, 12 (10%) were performed for malignant disease. Parathyroid tissue was removed inadvertently in 5 of 30 thyroidectomies (16.7%) and 17 of 96 total thyroid lobectomies (17.7%) or 17.4% of all thyroid operations during this time. None of the patients in whom a parathyroid gland was removed inadvertently became hypocalcaemic post-operatively and all of these patients were normocalcaemic when followed-up at six weeks. Conclusions: In specialist hands there is a risk of removing a single parathyroid gland of approximately 17% during thyroid surgery. However, this does not appear to carry a risk of causing hypocalcaemia post-operatively. Careful capsular dissection will reduce the incidence of removing more than one gland