BACKGROUND: The aim of this study is to describe the management and associated follow-up strategies adopted by thyroid surgeons with different surgical volumes when loss of signal (LOS) occurred on the first side of planned bilateral thyroid surgery, and to further define the consensus on intraoperative neuromonitoring (IONM) applications.
METHODS: The International Neural Monitoring Study Group (INMSG) web-based survey was sent to 950 thyroid surgeons worldwide. The survey included information on the participants, IONM team/equipment/procedure, intraoperative/postoperative management of LOS, and management of LOS on the first side of thyroidectomy for benign and malignant disease.
RESULTS: Out of 950, 318 (33.5%) respondents completed the survey. Subgroup analyses were performed based on thyroid surgery volume: <50 cases/year (n = 108, 34%); 50 to 100 cases/year (n = 69, 22%); and >100 cases/year (n = 141, 44.3%). High-volume surgeons were significantly (P < .05) more likely to perform the standard procedures (L1-V1-R1-S1-S2-R2-V2-L2), to differentiate true/false LOS, and to verify the LOS lesion/injury type. When LOS occurs, most surgeons arrange otolaryngologists or speech consultation. When first-side LOS occurs, not all respondents decided to perform stage contralateral surgery, especially for malignant patients with severe disease (eg, extrathyroid invasion and poorly differentiated thyroid cancer).
CONCLUSIONS: Respondents felt that IONM was optimized when conducted under a collaborative team-based approach, and completed IONM standard procedures and management algorithm for LOS, especially those with high volume. In cases of first-site LOS, surgeons can determine the optimal management of disease-related, patient-related, and surgical factors. Surgeons need additional education on LOS management standards and guidelines to master their decision-making process involving the application of IONM.

UNASSIGNED: Even though the use of nerve monitoring during parotid gland surgery is not the gold standard to prevent damage to the nerve, it surely offers some advantages over the traditional approach. Different from thyroid surgery, where a series of steps in intraoperative nerve monitoring have been described to confirm not only the integrity but-most importantly-the function of the recurrent laryngeal nerve, in parotid gland surgery, a formal guideline to follow while dissecting the facial nerve has yet to be described.
UNASSIGNED: A five-year retrospective study was done reviewing the intraoperative records of patients who underwent parotid gland surgery under neural monitoring. The operative findings regarding the neuromonitoring process, particularly in regard to the amplitude of two main branches, were revised. A literature search was done to search for guidelines to follow when a facial nerve loss of signal is encountered.
UNASSIGNED: Fifty-five patients were operated on using the Nim 3 Nerve Monitoring System (Medtronic); 31 were female patients, and 47 patients had benign lesions. Minimum changes were observed in the amplitude records after a comparison was made between the first and the last stimulation. There were only three articles discussing the term loss of signal during parotid gland surgery.
UNASSIGNED: Today, no sufficient attention has been given to the facial nerve monitoring process during parotidectomy. This study proposes a formal guideline to follow during this procedure as well as an instruction to consider when a loss of signal is observed to develop a uniform technique of facial nerve stimulation.

UNASSIGNED: This study was performed to compare the real-time electromyographic (EMG) changes and the rate of recurrent laryngeal nerve (RLN) injury in craniocaudal and lateral approaches for RLN during thyroidectomy.
UNASSIGNED: One hundred twelve and 86 patients were prospectively randomized to receive lateral (group 1) or craniocaudal (group 2) approach to RLN, respectively, under continuous intraoperative nerve monitoring.
UNASSIGNED: Loss of signal (LOS) occurred in 7 (2.0%) of 356 nerves at risk (NAR). LOS was significantly associated with repeated adverse EMG changes and presence of RLN entrapment at the ligament of Berry (LOB), which was accompanied by other clinicopathological or anatomical features, such as tubercle of Zuckerkandl (TZ), extralaryngeal branching, hyperthyroidism, autoimmune thyroid disease (ATD), or thyroid lobe volume of >29 cm3 (P = 0.001 and P = 0.030, respectively). The rate of repeated adverse EMG changes and LOS in the NARs with LOB entrapment accompanied by other clinicopathological and anatomical features was higher in group 1 vs. group 2 (11.1% vs. 2.2%, respectively and 9.7% vs. 0%, respectively; P = 0.070). The total rate of vocal cord palsy (VCP) was significantly higher in group 1 than in group 2 (P = 0.005). The rate of permanent VCP showed no significant difference between the 2 groups.
UNASSIGNED: The craniocaudal approach to the RLN is safer than the lateral approach in the RLNs with entrapment at the LOB accompanied by other features, such as TZ, extralaryngeal branching, hyperthyroidism, ATD, or high thyroid lobe volume.

The safety of thyroid surgery in terms of recurrent laryngeal nerve palsy and hypoparathyroidism has increased over the last decade. In this study, we present a new method of tension-free thyroidectomy (TFT), which could be used to further decrease the complication rate after a thyroidectomy. The procedure is based on the medial approach to the recurrent laryngeal nerve and the parathyroid glands after the division of the isthmus and successive complete dissection of Berry\'s ligament. In total, 92 patients (127 nerves at risk) underwent \"tension-free thyroidectomy\" (TFT) between August and November 2021. All the procedures were performed by a single surgeon at Saint Petersburg State University Hospital. There were 74 females and 18 male patients (ratio 4.1:1) with a mean age of 46.9 (range from 17 to 74). A lobectomy was carried out in 57 (62%) patients and a total thyroidectomy in 35 (38%). In 27 cases, patients additionally underwent central and/or lateral neck dissection. Indications for surgery were papillary carcinoma (N = 34), medullary cancer (N = 2), follicular neoplasia (N = 43), Grave\'s disease (N = 9), multinodular toxic goiter (N = 3), and multinodular nontoxic goiter (N = 1). Mean thyroid volume was 24.6 ml (ranged 12-70 ml). Intraoperative neuromonitoring was used in all the cases (5 mA). Translaryngeal ultrasound (TLUS) or direct laryngoscopy were routinely used prior and after surgery to evaluate vocal cords mobility. Calcium and parathormone levels were measured in patients after thyroidectomy on the first, 14th and 30th postoperative days. No recurrent laryngeal nerve palsy was observed. One patient exhibited hypoparathyroidism which was resolved in 2 weeks using substitution therapy with calcium and alfacalcidol. The mean operating time for lobectomy was 54 ± 14 min (range: 30-95 min) and for total thyroidectomy 99 ± 28 min (range: 55-158 min). There was no conversion to the conventional lateral-to-medial approach. TFT can be considered a safe and feasible operation. Comparative (randomized studies) with conventional dissection technique should be performed to investigate the hypothesis that this approach can provide a lower complication rate.

The aim of this study was to evaluate the effect of a single early administration of dexamethasone and escin after loss of signal (LOS) during a neuromonitored total thyroidectomy.
A retrospective analysis of results concerning consecutive patients undergoing total thyroidectomy was performed. Patients included in the study were divided into two groups: Group 1 for which a \"wait and see\" strategy was used; Group 2, receiving dexamethasone and escin immediately after LOS detection.
Overall 37 patients were included in Group 1 and 35 in Group 2. LOS recovery occurring in 29.7% of cases (n. 11) versus 65.7% (n. 23) respectively (p < 0.001). Postoperative fibrolayngoscopy for patients without LOS recovery showed normal cord function in 4 out of 26 cases (15.4%) in Group 1 and in 7 out of 12 (58.3%) in Group 2 (p < 0.001).
The early administration of dexamethasone and escin after LOS detection may achieve greater EMG signal recovery than a \"wait and see\" strategy.

BACKGROUND: Impact on blood flow by double vein anastomosis in head and neck free flaps is unclear. We aimed to assess venous doppler loss of signal (LOS) rates of double vein system compared with a single vein system.
METHODS: Consecutive free flaps with implanted venous flow couplers between 2015-2017 were included. LOS rates were compared between groups and with regard to flap type, defect site and recipient vein within double vein group.
RESULTS: 92 double-vein (184 veins) and 48 single-vein flaps were included. LOS was similar in single- and double-vein flaps (11/48 (25%) versus 46/184 (25%), p = 0.765). Double veins had fewer flap takebacks compared with single vein (4.3% vs. 12.5%, p = 0.075). Common facial vein (CFV) anastomosis showed superior LOS rates compared with external jugular and CFV branches (p = 0.026).
CONCLUSIONS: Double vein anastomosis does not impact LOS rates, results in fewer flap takebacks, yet LOS rates depend on selected recipient vein.

Background: The recurrent laryngeal nerve (RLN) can be injured during thyroid surgery, which can negatively affect a patient\'s quality of life. The impact of intraoperative anatomic variations of the RLN on nerve injury remains unclear. Objectives of this study were to (1) better understand the detailed surgical anatomic variability of the RLN with a worldwide perspective; (2) establish potential correlates between intraoperative RLN anatomy and electrophysiologic responses; and (3) use the information to minimize complications and assure accurate and safe intraoperative neuromonitoring (IONM). Methods: A large international registry database study with prospectively collected data was conducted through the International Neural Monitoring Study Group (INMSG) evaluating 1000 RLNs at risk during thyroid surgery using a specially designed online data repository. Monitored thyroid surgeries following standardized IONM guidelines were included. Cases with bulky lymphadenopathy, IONM failure, and failed RLN visualization were excluded. Systematic evaluation of the surgical anatomy of the RLN was performed using the International RLN Anatomic Classification System. In cases of loss of signal (LOS), the mechanism of neural injury was identified, and functional evaluation of the vocal cord was performed. Results: A total of 1000 nerves at risk (NARs) were evaluated from 574 patients undergoing thyroid surgery at 17 centers from 12 countries and 5 continents. A higher than expected percentage of nerves followed an abnormal intraoperative trajectory (23%). LOS was identified in 3.5% of NARs, with 34% of LOS nerves following an abnormal intraoperative trajectory. LOS was more likely in cases of abnormal nerve trajectory, fixed splayed or entrapped nerves (including at the ligament of Berry), extensive neural dissection, cases of cancer invasion, or when lateral lymph node dissection was needed. Traction injury was found to be the most common form of RLN injury and to be less recoverable than previous reports. Conclusions: Multicenter international studies enrolling diverse patient populations can help reshape our understanding of surgical anatomy during thyroid surgery. There can be significant variability in the anatomic and intraoperative characteristics of the RLN, which can impact the risk of neural injury.

(1) Background: Pediatric thyroidectomy is characterized by considerable space constraints, thinner nerves, a large thymus, and enlarged neck nodes, compromising surgical exposure. Given these challenges, risk-reduction surgery is of paramount importance in children, and even more so in pediatric thyroid oncology. (2) Methods: Children aged ≤18 years who underwent thyroidectomy with or without central node dissection for suspected or proven thyroid cancer were evaluated regarding suitability of intermittent vs. continuous intraoperative neuromonitoring (IONM) for prevention of postoperative vocal cord palsy. (3) Results: There were 258 children for analysis, 170 girls and 88 boys, with 486 recurrent laryngeal nerves at risk (NAR). Altogether, loss of signal occurred in 2.9% (14 NAR), resulting in six early postoperative vocal cord palsies, one of which became permanent. Loss of signal (3.5 vs. 0%), early (1.5 vs. 0%), and permanent (0.3 vs. 0%) postoperative vocal cord palsies occurred exclusively with intermittent IONM. With continuous nerve stimulation, sensitivity, specificity, positive and negative predictive values, and accuracy reached 100% for prediction of early and permanent postoperative vocal cord palsy. With intermittent nerve stimulation, sensitivity, specificity, positive and negative predictive values, and accuracy were consistently lower for prediction of early and permanent postoperative vocal cord palsy, ranging from 78.6% to 99.8%, and much lower (54.2-57.9%) for sensitivity. (4) Conclusions: Within the limitations of the study, continuous IONM, which is feasible in children ≥3 years, was superior to intermittent IONM in preventing early and permanent postoperative vocal cord palsy.

UNASSIGNED: Intraoperative posterior cricoarytenoid muscle (PCAM) electromyography (EMG) may be useful for predicting postoperative vocal cord function (VCF) and prognosis of vocal cord palsy (VCP) in patients with intraoperative loss of signal (LOS).
UNASSIGNED: Thirty out of 395 patients having LOS detected by intraoperative neural monitoring (IONM), were applied intraoperative PCAM EMG.
UNASSIGNED: VCP was present in all Type 1 injury RLNs (16) (100%) and in 8 (57%) of 14 RLNs with Type 2 injury (p = 0.005). 14 out of 30 LOS patients (47%) had positive PCAM EMG amplitudes. The sensitivity, specificity, positive and negative predictive values and accuracy rates for predicting postoperative VCP via PCAM EMG, were calculated as 66.7%, 100%,100%, 42.86% and 73.33%. The negative PCAM EMG was related to VCP in both Type 1 and Type 2 LOS. VCP recovery time of Type 1 LOS patients was significantly longer than that of Type 2 LOS patients (p = 0.009). In Type 2 LOS, VCP recovery time was significantly longer in negative PCAM EMG patients compared to positive PCAM EMG patients (p = 0.046).
UNASSIGNED: Negative PCAM EMG is associated with the postoperative VCP. Type 1 injury results in VCP regardless of PCAM EMG results, and VCF recovers after a longer period compared to Type 2 LOS.In Type 2 LOS, positive PCAM EMG may result in VCP by 40%. However, the presence of negative PCAM EMG is related to the postoperative VCP in all patients and the recovery time is longer compared to positive PCAM EMG patients.

OBJECTIVE: Bilateral vocal cord dysfunction (bVCD) is a rare but feared complication of thyroid surgery. This long term retrospective study determined the effect of intraoperative neuromonitoring (IONM) of the recurrent laryngeal nerve (RLN) during thyroid surgeries with regard to the rate of bVCD and evaluated the frequency as well as the outcome of staged operations.
METHODS: Retrospective analysis of prospectively documented data (2000-2019) of a tertiary referral centers\' database. IONM started in 2000 and, since 2010, discontinuation of surgery was encouraged in planned bilateral surgeries to prevent bVCD, if non-transient loss of signal (ntLOS) occurred on the first side. Datasets of the most recent 40-month-period were assessed in detail to determine the clinical outcome of unilateral ntLOS in planned bilateral thyroid procedures.
RESULTS: Of 22,573 patients, 65 had bVCD (0.288%). The rate of bVCD decreased from 0.44 prior to 2010 to 0.09% after 2010 (p < 0.001, Chi2). Case reviews of the most recent 40 months period identified ntLOS in 113/3115 patients (3.6%, 2.2% NAR), of which 40 ntLOS were recorded during a planned bilateral procedure (n = 952, 2.1% NAR). Of 21 ntLOS occurring on the first side of the bilateral procedure, 15 procedures were stopped, subtotal contralateral resections were performed, and thyroidectomy was continued in 3 patients respectively, with the use of continuous vagal IONM. Eighteen cases of VCD were documented postop, and all but one patient had a full recovery. Seven patients had staged resections after 1 to 18 months (median 4) after the first procedure.
CONCLUSIONS: IONM facilitates reduced postoperative bVCD rates. IONM is, therefore, recommendable in planned bilateral procedures. The rate of non-complete bilateral surgery after intraoperative non-transient LOS was 2%.