Morbidity of prophylactic lymph node dissection in the central neck area in patients with papillary thyroid carcinoma

The benefits of prophylactic central neck dissection (PCND) in patients with papillary thyroid carcinoma (PTC) have not been clearly demonstrated so far and should be weighed against the potential risks of the procedure. The aim of the study was to assess the recurrent laryngeal nerve and parathyroid risks of PCND after total thyroidectomy in patients with PTC and to compare the results with those obtained in patients who underwent total thyroidectomy only.

We selected 100 patients who underwent a total thyroidectomy: 50 for nontoxic benign multinodular goiter (Group 1) and 50 for PTC (Group 2). Patients with PTC had no evidence of macroscopic lymph node invasion during surgery and underwent, in addition to the total thyroidectomy, a PCND. All of the 100 patients were operated on by two experienced endocrine surgeons. All patients had pre- and postoperative investigations of vocal cord movements. Calcemia and phosphoremia were systematically evaluated preoperatively and on day 1 and day 2 after surgery. All patients presenting a postoperative calcemia below 1.90 mmol/l were considered to present an early postoperative hypoparathyroidism and received calcium-vitamin D therapy. The hypoparathyroidism was considered permanent when calcium-vitamin D therapy was still necessary 1 year after surgery.

None of the patients presented permanent nerve palsy. There were three cases of transient nerve palsy (6%) in Group 1 and two (4%) in Group 2. In Group 1 there was no permanent hypoparathyroidism and four cases of transient hypoparathyroidism (8%). In Group 2, seven patients presented transient hypoparathyroidism (14%) and two patients (4%) remained with definitive hypoparathyroidism.

After total thyroidectomy for PTC, PCND does not increase recurrent laryngeal nerve morbidity but it is responsible for a high rate of hypoparathyroidism, especially in the early postoperative course. Even taking into account the possible benefits, the results make it difficult to advocate PCND as a routine procedure in all patients presenting a PTC.