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Intraoperative neuromonitoring (IONM) facilitates recurrent laryngeal nerve (RLN) protection in thyroid and parathyroid surgeries. This study aimed to investigate a novel transcutaneous electromyography (EMG) recording method for IONM of the RLN during minimally invasive parathyroidectomy (MIP). Twenty patients with primary hyperparathyroidism undergoing MIP were enrolled. Two paired needle electrodes were percutaneously inserted into the bilateral laminas of thyroid cartilage for monitoring the vagus nerve and RLN. A standardized IONM procedure (V1-R1-R2-V2 signals) was strictly followed, and the RLN was routinely located and mapped. Pre- and postoperative laryngofiberoscopy was performed to confirm vocal cord function. The proposed technique was successfully used in all patients, and typical EMG signals were effectively detected. No significant change in EMG signals before and after tumor resection was noted, and a normal vocal cord movement was ensured in all patients with postoperative laryngofiberoscopy. IONM helped localize the position of the RLN and facilitated the safe resection of the parathyroid tumor during MIP. The novel transcutaneous EMG recording method proposed in this study was feasible, convenient, reliable, and inexpensive. [ABSTRACT FROM AUTHOR]

Purpose: During monitored thyroidectomy, a partially or completely disrupted point of nerve conduction on the exposed recurrent laryngeal nerve (RLN) indicates true electrophysiologic nerve injury. Complete loss of signal (LOS; absolute threshold value <100 μV) at the end of operation often indicates a postoperative vocal cord (VC) palsy. However, the evaluation for the injured RLN with incomplete LOS and its functional outcome has not been well described. Methods: Three hundred twenty-three patients with 522 RLNs at risk who underwent standardized monitored thyroidectomy were enrolled. The RLN was routinely stimulated at the most proximal (R signal) and distal (R signal) ends of exposure after thyroid resection to determine if there was an injured point on the RLN. Pre- and postoperative VC function was routinely examined. Results: Twenty-nine RLNs (5.6 %) were detected with an injury point. Five nerves had complete LOS and other 24 nerves had incomplete LOS where the R/R reduction (% of amplitude reduction compared with proximal to distal RLN stimulation) ranged from 22 to 79 %. Postoperative temporary VC palsy was noted in those five RLNs with complete LOS (final vagal signal, V < 100 μV) and four RLNs with incomplete LOS (R/R reduction 62-79 %; V 181-490 μV). In the remaining 20 nerves with R/R reduction ≤53 % (V 373-1623 μV), all showed normal VC mobility. Overall, false negative results were found in two RLNs (0.4 %) featuring unchanged V and R/R but developed VC palsy. Conclusions: Testing and comparing the R/R signal is a simple and useful procedure to evaluate RLN injury after its dissection and predict functional outcome. When the relative threshold value R/R reduction reaches over 60 %, surgeon should consider the possibility of postoperative VC palsy. [ABSTRACT FROM AUTHOR]

Purpose: The vagus nerve (VN) has essential regulatory roles in the gastric acid secretion and gastrin release. Continuous intraoperative neuromonitoring (CIONM) via VN stimulation is a promising technique in thyroid surgery because it potentially avoids injury to the recurrent laryngeal nerve. However, no studies have investigated changes in gastric acid secretion and gastrin release during CIONM. Method: This prospective study of 58 thyroid surgery patients compared gastric acid and serum gastrin at five time points: (1) before skin incision, (2) after baseline calibration of CIONM probe, (3) +20 min from baseline, (4) before probe removal, and (5) after extubation. Patients were excluded if they had any history of using tobacco, acid suppression medications, or drugs that affect gastric motility. Patients were also excluded if they had any history of gastroesophageal reflux symptoms, gastroesophageal reflux disease, peptic ulcer disease, helicobacter pylori infection, or chronic kidney disease. Results: Non significant differences in mean gastric pH values were observed at all time points, i.e., (1) before skin incision (2.2 ± 0.2; p = 0.50), (2) after baseline calibration of CIONM probe (2.0 ± 0.8; p = 0.62), (3) +20 min from baseline (2.5 ± 0.5; p = 0.24), (4) before probe removal (2.9 ± 0.9; p = 0.52), and (5) after extubation (2.6 ± 1.0; p = 0.60). Comparisons of pH monitoring parameters revealed no significant differences in age, gender, side of CIONM (left vs. right), sequence of CIONM, or duration of CIONM. Gastrin values were normal in sequential determinations and did not significantly differ at any time points. Conclusions: CIONM performed via VN stimulation during total thyroidectomy in healthy patients does not influence gastrin secretion and gastric pH. [ABSTRACT FROM AUTHOR]

The objective is to compare the consequences of routine visualization (RV) and the application of intermitted (I-IONM), standardized (S-IONM), and continuous monitoring (C-IONM) of recurrent laryngeal nerve (RLN) management. RV includes that 698 RLNs managed solely with visual identification. In a second period 777, RLNs were handled by the I-IONM. The third period 768 RLNs monitoring was performed according to the standards. C-IONM via VN stimulation included 626 RLNs. The following issues were analyzed and compared per each period study: RLN identification rate, branching detection, assessment of NRLN, intraoperative recognizable nerve damage, stage thyroidectomy rate, transient or definitive lesions, bilateral nerve palsy, and recovery time. Significance for nerve identification rate was achieved ( p = 0.03) when the statistical analysis was applied between RV vs. S-IONM and C-IONM. Extralaryngeal bifurcation was identified in 21, 44, 43, and 46 of RLN dissected, respectively, per period ( p = 0.005). The incidence of paralysis in identified and unidentified RLN was 3.8 % (107/2806) and 82 % (52/63), respectively. Rates of temporary/permanent RLNP were 16.7/1.7, 5/1.1, 4.5/1, and 3.1/0 % per period study, respectively ( p = 0.07). Recognizable intraoperatively nerve damage was, respectively, 15, 45, 100, and 100 % for period study (p = 0.03). The recovery of injured nerves was significantly faster in C-IONM group. S-IONM and C-IONM cumulate 40-stage procedures. The standardized technique, guidelines adherences, and C-IONM allowed to (1) increase RLN identification; (2) reduce the severity of injuries in terms of (a) reset bilateral RLNP, (b) faster recovery time, and (c) lower definitive RLNP; (3) gather detection of branching and NRLN; (4) recognize nerve stress; and (5) cumulate stage procedures. [ABSTRACT FROM AUTHOR]

Purposes: Cernea classification is applied to describe the external branch of the superior laryngeal nerve (EBSLN). Using intraoperative neural monitoring we evaluated whether or not this classification is useful for predicting which EBSLN subtype has an increased risk of injury. Methods: An analysis of 400 EBSLN. The identification of EBSLN was achieved with both cricothyroid muscle twitch and the glottis evoked electromyography response. We defined S1 initial EBSLN stimulation at identification and S2 final nerve stimulation achieved in the most cranial aspect of the nerve exposed above the area of surgical dissection after superior artery ligation. Results: The mean S1 amplitude acquired was 259+/67 (180-421), 321 +/79 (192-391), 371 +/38 (200-551) μV, respectively, for type 1, 2A, 2B ( p = 0.08). The S1 and S2 amplitudes were similar in type 1 ( p = 0.3). The S1 and S2 determinations changed significantly in type 2A and 2B ( p = 0.04 and 0.03). EBSLN which demonstrated a >25 % decreased amplitude in S2 increased significantly from Type 1 (4.9 %) to Type 2A (11.2 %) and 2B (18 %) ( p = 0.01). None of type 1, 2.8 % type 2A and 3 % type 2B showed a loss of EBSLN conductivity. The latency determinations did not vary significantly for any parameter compared. Conclusions: The Cernea classification was, therefore, found to predict the risk of EBSLN stress. We identified amplitude differences between S1 and S2 determinations in type 2A and 2B, thus confirming that surgical dissection in these subtypes is, therefore, extremely difficult to perform. [ABSTRACT FROM AUTHOR]

Three types of popular vendors, including meat and non-meat food (e.g, fishballs), vendor group (I), rice sausage sandwiches vendor group (II), and roasted corn on-the-cob vendor group (III), from the night markets of Taiwan were chosen for this research. The average concentrations of carcinogenic polycyclic aromatic hydrocarbons (car-PAHs) were 2445 ng/m3 for vendor (II), 2276 ng/m3 for vendor (II), and 133 ng/m3 for vendor (III). Vendors groups (I) and (II) had exposure levels of Benzo(a)pyrene (BaP)-equivalent doses (BaPeq) approximately 16 and 13 times higher than those for vendor group (III). The daily exposure doses of BaPeq in working duration for vendor group (II) and (II) were 2.80 and 2.28 μg/day, respectively. The employees of five offices on campus were chosen as a control group. The daily exposure doses of BaPeq during working hours for vendor group (II) and (II) were about 22 times and 18 times, respectively, higher than those for control group. This exposure dose for vendors group (III) (0.18 μg/day) was comparable with the dose for control group (0.13 μg/day). The whole-day exposure doses of t-PAHs, car-PAHs, BaP, and BaPeq for vendor groups (I) and (II) were very close to those during daily working hours. However, the daily exposure doses of BaPeq during working hours for vendor group (III) occurred only in a proportion of 62% of the whole-day exposure doses. [ABSTRACT FROM AUTHOR]