Effect of Dissection of the Recurrent Laryngeal Nerves on Parathyroid Insufficiency during Total Thyroidectomy for Multinodular Goitre.

Introduction: Total thyroidectomy is the accepted standard treatment for benign goitrous enlargements. The surgical skill and technique is one of the most important factor which affect the outcome in thyroid surgery. Hypocalcaemia due to parathyroid insufficiency remains a significant postoperative morbidity after total thyroidectomy. The primary cause is unintentional damage to, or devascularization of, one or more parathyroid glands during surgery.

Aim: To study the risk of hypocalcaemia due to recurrent laryngeal nerves (RLNs) dissection during total thyroidectomy for benign multinodular goitre (MNG).

Materials And Methods: The study is a non-randomized control trial, where 100 patients with benign MNG were divided into two groups (group A and group B) each consisting of 50 patients. All 100 patients underwent total thyroidectomy by a subcapsular dissection. In patients of group A, both RLNs were clearly dissected for a minimum length of 2cm down from its entry into the larynx before total thyroidectomy was performed. In group B, each patient had total thyroidectomy without making any deliberate attempt to dissect and demonstrate the RLNs. The patients in the two groups were followed up for the incidence of clinically significant hypocalcaemia in the postoperative period.

Results: A total of 30% of patients in group A developed clinical and biochemical manifestations of hypocalcaemia but the incidence of hypocalcaemia was only 6% in the group B. Three (6%) patients out of those who developed hypocalcaemia in group A had a prolonged hypocalcaemia for upto six months. p-value is 0.003 and odds ratio is 6.59.

Conclusion: Routine dissection to identify the RLNs could predispose to a higher incidence of postop hypocalcaemia. Subcapsular dissection of the thyroid safely preserves the parathyroid glands.