IONM and thyroidectomy in benign thyroid disease. Analysis of adverse events.

OBJECTIVES: The aim of this study is to identify statistically significant differences in the onset of postoperative complications in patients undergoing thyroid surgery for benign pathology, following the systematic introduction of intraoperative neuromonitoring (IONM) of the laryngeal nerves. MATERIALS AND METHODS: In this study we have retrospectively analysed data of 604 consecutive patients underwent to thyroidectomy in the Unit of General Surgery - University Hospital of Parma between January 2011 and December 2017. All patients were divided in two groups: the first group of patients was operated without the use of IONM (Group A) the second group was operated after the introduction of the systematic use of IONM (Group B). We have compared the incidence of adverse events in these two groups, analysing the impact of IONM on the onset of the most frequent complications after thyroid surgery. We have considered the impact of other variables in both groups, such as thyroiditis, hyperfunction and gland sinking in mediastinum. RESULTS: No statistically significant differences in the incidence between Group A (patients operated without the use of IONM) and Group B (patients operated with the use of IONM) were detected, though a decreasing trend after the introduction of IONM was observed. No statistically significant differences were reported even analysing the influence of other patient's variables such as thyroiditis, hyperfunction and glandular sinking in mediastinum. CONCLUSION: Even if the number of patients considered is not sufficient to value statistically significant differences, the decreasing trend of the incidence of postoperative complications after introduction of IONM encourage us. The surgeon expertise is still the most relevant variable influencing the decreasing of postoperative complications, underlining the importance of the centralization of this kind of surgery in the high volume centres.

IONM and minimally invasive videoassisted thyroidectomy.

BACKGROUND: We know that benefits of MIVAT are related to a better cosmetic result and lower post-operative pain in comparison to CT. The incidence of nerve cold palsy is related to a correct identification of the recurrent laringeal nerve (RLN) as standard procedure in thyroid surgery. From September 2014 we have introduced the use of intraoperative neural monitoring(I-IONM) in all thyroidectomies in the Unit of General Surgery of University Hospital of Parma, including in MIVAT. PATIENTS AND METHODS: We have considered all patients treated from September 2014 to September 2017 for thyroid diseases using MIVAT and IONM. Intermittent neuromonitoring with NIM-3.0 equipment (Medtronic, Jacksonville, FL, USA) was used during all operations. We have recorded all data about age, sex, diagnosis, surgical time, i-IONM signal, postoperative pain, postoperative hypocalcemia after 24 hours, haematoma and vocal cord palsy. The mean hospital stay was collected from surgical procedure to hospital discharge. We have considered vocal dysfunctions that persist six months after surgery as permanent. RESULTS: From September 2014 to September 2017 we treated consecutively with both MIVAT and i-IONM 100 patients. Considering the extent of surgery, 26 pts underwent to hemithyroidectomy and 74 pts to total thyroidectomy. The mean surgical time was 61.8 minutes. In 7 cases the patients were affected by preoperative clinical dysphonia. Using I-IONM during thyroidectomy, we recorded in 5 cases (5%) a loss of signal; in two cases (2%) we experienced a temporary postoperative vocal cord palsy. DISCUSSION: In our experience the use of IONM has improved the safety during thyroidectomy because precision that can be achieved by endoscopic procedures is further improved by complementary use of IONM. The costs associated to a potential reduction of medical litigation have not been investigated.