The occurrence of chyle leakage after central compartment dissection even without lateral neck dissection was not rare, but was easily controlled with conservative management. Surgical management should be considered if the drainage amount does not decrease by >50% of the original amount of the day of detection after 2 days of NPO.

BACKGROUND AND AIMS The efficacy of prophylactic central neck dissection (pCND) in patients with papillary thyroid carcinoma (PTC) is still unclear. The aim of this prospective randomized controlled study was to evaluate the clinical strengths and weaknesses of pCND. METHODS Between May 2009 and September 2015, a total of 1,134 patients with clinical N0 PTC were randomly assigned to two groups. Group A was treated with thyroidectomy alone and group B was treated with thyroidectomy + pCND. When the surgeon detected extrathyroidal extension or suspicious lymph nodes during the operation, frozen biopsy was performed to confirm the metastasis and the patients were excluded. We analyzed the clinicopathologic characteristics, postoperative complications, and recurrence. RESULTS Of the 1,134 patients, 110 were excluded because they had evidence of either capsular invasion or lymph node metastasis proven by frozen biopsy during the operation (rate of dropout: 9.7%). A total of 1,024 patients were included, 504 patients in group A and 520 patients in group B. In group B, 67 patients had ipsilateral central lymph node metastasis in frozen biopsy that were converted to total thyroidectomy. Clinicopathologic characteristics of the two groups were not significantly different. The median follow-up period was 20 months (1–77 months). Recurrence was detected in three patients (0.3%) in the lateral lymph node. Disease-free survival was not statistically significantly different between the two groups (p = 0.561). However, the incidence of temporary hypoparathyroidism in group B was significantly higher than that in group A (group A: 13.1%, group B: 20.8%, p = 0.001), while the permanent hypoparathyroidism, vocal cord palsy, chyle leakage, bleeding, and wound infection were similar between groups A and B. CONCLUSION Prophylactic central neck dissection did not reduce locoregional recurrence in clinical N0 PTC, but it significantly increased the incidence of transient hypoparathyroidism. But the assessment of effectiveness of pCND in reducing recurrence and mortality requires a long-term follow-up.