Purpose: The extent of prophylactic lateral neck lymph node dissection is very controversial in medullary thyroid cancer. This retrospective study was undertaken to evaluate the efficacy of prophylactic lateral neck lymph node dissection. Methods: A total of 29 patients underwent curative operation for medullary thyroid carcinoma at our institution. Of these 29 patients, 13 patients had prophylactic lateral neck dissec-tion and 16 patients had non-prophylactic lateral neck dissection. Among 13 patients, one-compartment prophylac-tic lymph node dissection was performed in 10 patients and two-compartment prophylactic lymph node dissection was performed in 3 patients. Postoperative calcitonin level was evaluated between these groups. Results: A normalized calcitonin level was detected after surgery in 74% of patients without lateral neck lymph node metastases, and in 10% of patients with lateral neck lymph node metastases. In comparison of prophylactic node dissec-tion group and non-prophylactic node dissection group, the rate of normalized calcitonin level after surgery is 100%, 66.7% in stage 1, 100%, 50% in stage 2, 0%, 80% in stage 3, 14.3%, 0% in stage 4. In the patients who one-compartment prophylactic lymph node dissection was performed, 40% of patients had positive lymph node metastasis, and 70% had persistent hypercalcitoninemia. However, there was no post-operative hypercalcitoninemia in the patients with two-compartment prophylactic lymph node dissection although lymph node metastasis was not identified with pathologic examination. Conclusion: Prophylactic lymph node dissection was more effective in the early stage of medullary thyroid carcinoma than late stage. The two or more compartment lymph node dissection is more effective than just one-compartment dissection for the normalization of serum calcitonin level. (Korean J Endocrine Surg 2004;4:85-89)

BackgroundInjury to the external branch of the superior laryngeal nerve (EBSLN) during thyroidectomy results in a lowered fundamental frequency of the voice and deteriorated voice performance in producing high-frequency sounds. It remains unclear if the use of intraoperative nerve monitoring (IONM) can improve the clinical outcome of thyroidectomy in terms of preserved individual voice performance. This study was designed to test that hypothesis.MethodsA total of 210 consenting female patients planned for total thyroidectomy were randomly assigned to two groups equal in size (n = 105): visual inspection of the EBSLN and RLN vs. this plus additional EBSLN and RLN monitoring. The primary outcome was the identification rate of the EBSLN. The secondary outcomes included: anatomical variability of the EBSLN according to the Cernea classification and changes in postoperative voice performance. Voice assessment included pre- and postoperative videostrobolaryngoscopy and an analysis of maximum phonation time (MPT), voice level (VL), fundamental frequency (Fo), and voice quality rating on the GRBAS scale.ResultsThe following differences were found for operations without vs. with IONM: identification rate of the EBSLN was 34.3 % vs. 83.8 % (p < 0.001), whereas a 10 % or higher decrease in phonation parameters was found in 10 % vs. 2 % patients for MPT (p = 0.018), 13 % vs. 2 % for VL (p = 0.003), and 9 % vs. 1 % for Fo (p = 0.03), a change in the GRBAS scale > 4 points in 7 % vs. 1 % (p = 0.03), and temporary RLN injury was found in 2 % vs. 1 % (p = 0.56), respectively.ConclusionsThe use of IONM significantly improved the identification rate of the EBSLN during thyroidectomy, as well as reduced the risk of early phonation changes after thyroidectomy.

BackgroundThe prevalence of recurrent laryngeal nerve (RLN) injury is higher in repeat than in primary thyroid operations. The use of intraoperative nerve monitoring (IONM) as an aid in dissection of the scar tissue is believed to minimize the risk of nerve injury. The aim of this study was to examine whether the use of IONM in thyroid reoperations can reduce the prevalence of RLN injury.MethodsThis was a retrospective cohort study of patients who underwent thyroid reoperations with IONM versus with RLN visualization, but without IONM. The database of thyroid surgery was searched for eligible patients (treated in the years 1993–2012). The primary outcomes were transient and permanent RLN injury. Laryngoscopy was used to evaluate and follow RLN injury.ResultsThe study group comprised 854 patients (139 men, 715 women) operated for recurrent goiter (n = 576), recurrent hyperthyroidism (n = 36), completion thyroidectomy for cancer (n = 194) or recurrent thyroid cancer (n = 48), including 472 bilateral and 382 unilateral reoperations; 1,326 nerves at risk (NAR). A group of 306 patients (500 NAR) underwent reoperations with IONM and 548 patients (826 NAR) had reoperations with RLN visualization, but without IONM. Transient and permanent RLN injuries were found respectively in 13 (2.6 %) and seven (1.4 %) nerves with IONM versus 52 (6.3 %) and 20 (2.4 %) nerves without IONM (p = 0.003 and p = 0.202, respectively).ConclusionsIONM decreased the incidence of transient RLN paresis in repeat thyroid operations compared with nerve visualization alone. The prevalence of permanent RLN injury tended to be lower in thyroid reoperations with IONM, but statistical validation of the observed differences requires a sample size of 920 NAR per arm.

Miami criterion followed by Vienna criterion was found to be the best balanced among other criteria, with the highest accuracy in intraoperative prediction of cure. However, Rome criterion followed by Halle criterion was found to be the most useful in intraoperative detection of MGD. Nevertheless, their application in patients qualified for MIP with concordant results of sestamibi scanning and ultrasound of the neck would result in a significantly higher number of negative conversions to bilateral neck explorations and only a marginal improvement in the success rate of primary operations.

NCT01959711 (http://www.clinicaltrials.gov).