Abstract: Objective To study the protective effect of nerve detection technique(IONM) on recurrent laryngeal nerve(RLN) in Miccoli endoscopic assisted complex thyroid surgery.Methods The clinical data of one hundred and two patients who underwent complex thyroidectomy in our hospital from February 2019 to February 2020 were collected retrospectively.They were divided into two groups according to the time of admission,of which the patients selected from February 2019 to August 2019 were the control group and the patients selected from September 2019 to February 2020 were the observation group,with fifty-one cases in each group.The control group was treated with conventional RLN exposure combined with endoscopic assisted surgery in Miccoli mode,and the observation group was treated with endoscopic assisted surgery in IONM combined with Miccoli mode.The operation conditions(operation time,bleeding volume,RLN exploration time,drainage volume and hospital stay) of the two groups were compared,the pain degree [visual analog score(VAS score)] at 6 h,12 h and 24h after operation were compared,and the voice condition [voice disorder index(VHI score)] and the incidence of postoperative recurrent laryngeal nerve injury(RLNi) at 3 months after operation were evaluated.Results The bleeding of observation group was  ( 24.20 ±3.23)ml, volume of drainage was (30.52 ±4.36)ml, length of hospital stay was (4.26 ±0.58) days, while the data in the control group were (25.12±3.14)ml,(31.10±4.41)ml,(4.31±0.62)d, respectively.There was no significant difference between the two groups(P>0.05).The operation time(96.52±11.03)min and RLN exploration time(7.59±1.02)min in the observation group were shorter than those in the control group[(141.26±13.47)min and(13.10±2.23)min,P<0.05].The VAS scores at 6h,12h and 24h in the observation group were(4.36±1.07),(3.59±0.84) and(1.89±0.46),respectively,and the VAS scores at 6h,12h and 24h in the control group were(4.56±1.18),(3.66±0.95) and(1.93±0.52),respectively.The VAS score of the two groups decreased gradually after operation(P<0.05).However,there was no significant difference in VAS score between the two groups(P>0.05).The VHI score of the observation group(13.38±2.52) was lower than that of the control group(17.99±3.46) 3 months after operation(P<0.05).The total incidence of RLNi in the observation group was 3.92%,which was lower than the control group(17.65%,P<0.05).Conclusion IONM can shorten the exploration time and operation time of RLN in Miccoli endoscopic assisted complex thyroid surgery,improve the voice condition,reduce the incidence of RLNi,and improve the operation effect.

Key words: complex thyroidectomy, Miccoli model, endoscopic assistance, neural detection technology, recurrent laryngeal nerve, protective effect