ABSTRACT
ObjectiveTo investigate the effectiveness and feasibility of intraoperaive recurrent laryngeal nerve(RLN) monitoring via lateral cricoarytenoid muscle(LCA) compound muscle action potential (CMAP) monitoring by bipolar electrode implanting. MethodsSeventy-four cases were evenly divided into nerve monitoring group and non-monitoring group,NIM-Response 2.0 was applied into monitoring group for intraoperative nerve monitoring.A bipolar electrode was inserted into LCA to record CMAP,stimulating electrode intermittently stimulated exposed or unexposed recurrent laryngeal nerve to monitor the RLN function during cervical operation under the block anaesthesia of cervical plexus. ResultsThere were no statistically significant differences (P ＞ 0.05 ) in postoperative hospitalization days (5.14 ± 1.44 days,5.05 ± 1.31 days),operation time ( 125.54 ±42.23 min,107.30 ± 39.36 min) between monitoring group and the control group.Thirty-two RLNs were mapped their anatomical course with the NIM-Response 2.0 assistance before exposure,and 25 RLNs were anatomically exposed.The stimulating threshold between unexposed RLN (2.23 ± 0.57 mA) and exposed RLN ( 0.44 ± 0.20 mA) were statistically different ( P ＜ 0.01 ),but the evoked EMG amplitude(307.98 ± 253.47 μV,234.36 ± 142.18 μV) were not statistically different (P ＞ 0.05 ).With the NIM-Response 2.0 assistance the course of the unexposed RLNs detected were consistent to the course of the RLNs when exposed completely.ConclusionsIt is a effective and feasible method to monitor the RLN function by recording the CMAP of lateral cricoarytenoid muscle(LCA) via bipolar electrode implanted into LCA under block anaesthesia of the cervical plexus.
ABSTRACT
Objective To investigate the monitoring of the recurrent laryngeal nerve (RLN)function during thyroid surgery by recording the compound muscle action potential (CMAP) of lateral cricoarytenoid muscle(LCA) under block anaesthesia of the cervical plexus. Methods Nicolet Endeavor CR(Viasys Healthcare, USA) was applied for the intraoperative monitoring. A pair of needle electrodes were inserted into LCA to record CMAP, and a concentric electrode was used to intermittently stimulate the RLN for monitoring the RLN function during operation under block anaesthesia of the cervical plexus.Results In these 28 cases 31 RLNs were exposed during operation, CMAPs appeared with consistent latency when stimulation was applied at the exposed segment. The stimulating intensity threshold ranged from 0.2 to 1.6 mA. The average value was 0.96 mA. 25 of 31 showed CMAPs with consistent latency when stimulation was provided along the possible pathway of the unexposed segment. The stimulating intensity threshold ranged from 1.3 to 3.5 mA. The average value was 2. 03 mA. 6 of 31 did not evoked CMAP even though the maximal stimulating intensity was 5 mA. When these six nerves were exposured, compound muscle action potential were evoked consistently. All of the 28 patients had normal phonation function after surgery.Conclusions It is a safe, effective and feasible method to monitor the RL N function by recording the CMAP of lateral cricoarytenoid muscle under block anaesthesia of the cervical plexus.
ABSTRACT
OBJECTIVE To study the synchronous electromyograhic features of suprahyoid muscles [anterior digastric muscle(AD), posterior digastric muscle(PD),stylohyoid muscle(STH),mylohyoid muscle(MH)and geniohyoid muscle(GH)] and intrinsic laryngeal muscles [lateral cricoarytenoid muscle(LCA)and posterior cricoarytenoid muscle(PCA)]. METHODS Synchronous electromyograhic features of 13 dogs were observed under the circumstances of breath, swallowing and phonation. RESULTS ①AD, PD, STH, MH, GH and PCA discharged during inspiratory phase, while LCA discharged during expiratory phase. ②During swallow, suprahyoid muscles and LCA showed intensive synchronous discharge. The myoelectricity of PCA was suppressed while myopotential can be detected during intermission. ③During phonation, AD, PD, LCA and PCA showed an intensive synchronous discharge, while emergence time of PCA was later. GH and STH showed no myoelectricity activities. CONCLUSION①During phonation and swallowing, MH is synchronized with LCA. It can be chosen as the backup muscle for the reestablishment of glottic adduct function. ②During inspiratory phase, GH is synchronized with PCA. It can be chosen as the backup muscles for the reestablishment of vocal cord abduct function.