PARP-1 Involvement in Autophagy and Their Roles in Apoptosis of Vascular Smooth Muscle Cells under Oxidative Stress

Autophagy and poly(ADP-ribose) polymerase 1 (PARP-1) are activated and involved in a series of cell processes under oxidative stress, which is associated with pathogenesis of atherosclerosis. Research on their relationship under oxidative stress has been limited. In this study, we aimed to investigate the activation, relationship, and role of autophagy and PARP-1 in vascular smooth muscle cell (VSMC) death under oxidative stress. This study explored the signal molecule PARP-1 and autophagy in VSMCs using gene silencing and the hydrogen peroxide (H2O2)-stimulated oxidative stress model. We observed that H2O2 could induce autophagy in VSMCs, and the inhibition of autophagy could protect VSMCs against oxidative stress-mediated cell death. Meanwhile, PARP-1 could also be activated by H2O2. Additionally, we analysed the regulatory role of PARP-1 in oxidative stress-mediated autophagy and found that PARP-1 was a novel factor involved in the H2O2-induced autophagy via the AMPK-mTOR pathway. Finally, PARP-1 inhibition protected VSMCs against caspase-dependent apoptosis. These data suggested that PARP-1 played a critical role in H2O2-mediated autophagy and both of them were involved in apoptosis of VSMCs.

Analyzing cost-effectiveness of neural-monitoring in recurrent laryngeal nerve recovery course in thyroid surgery

PURPOSE

The increasing use of intraoperative neural monitoring (IONM) of the recurrent laryngeal nerve (RLN) during thyroid surgery imposes an evaluation of cost-effectiveness.

METHODS

The analysis estimated the cost versus utility of different alternatives that simulate nerve injury course and the consequences for the following cohorts of patients: (1) no RLN injury, or vocal fold palsy (VCP) recovery within 1 month (2), 2 months (3), 6 months (4), and after 12 months (5). In the model applied, the average simulated cohort consisted of a young female patient, 40 years old, employed, daily voice user, who underwent elective, conventional total thyroidectomy via cervical incision using a standardized intermittent IONM technique, for an operable benign, bilateral, diffuse, multinodular, non-toxic, non-retrosternal goiter.

RESULTS

IONM was cost-ineffective when parameters such as the rates of transient vocal fold palsy (VCP) reached 38.5%. IONM was cost-effective if the rate of VCP was 33.6% at 1 month, 22.9% at 2 months, 9.8% at 6 months, and 3.8% at 12 months, independent of phono-surgery. The described scenario is cost-effective only in a high-volume setting.

CONCLUSIONS

This study used simulation economic modeling to assess clinical and cost-effectiveness utility of IONM implementation. In light of the limitations of a simulation-based study, we conclusively assumed that IONM is cost-effective for permeant RLN injuries.

Preoperative, intraoperative and postoperative anesthetic prospective for thyroid surgery: what's new

The aim of this review is to analyze what's new on anesthetic prospective to perioperative management for thyroid surgery. For recent decades intraoperative neuromonitoring (IONM) during thyroid and parathyroid surgery has obtained more and more popularity. New modality of anesthetic technique was also developed to incorporate into surgical teamwork. For example, the precise position of EMG tube and optimal use of neuromuscular blocking agents (NMBAs) play key roles in successful IONM system. Special focus is paid to following issues: (I) preoperative airway evaluation and pre-op preparation; (II) anesthetic managements including advanced intubation tools, NMBAs and sugammadex; and (III) post-op adverse events such as pain and postoperative nausea vomiting.

Trachway video intubating stylet allows for optimization of electromyographic endotracheal tube placement for monitored thyroidectomy

Background

Endotracheal tube-based surface electrodes are now commonly applied to measure evoked electromyographic (EMG) response of the vocal cord during monitored thyroidectomy. The aim of the study was to determine the incidence of difficult intubation and to assess the effectiveness of using video-assisted intubating stylet (Trachway) for EMG tube placement in patients undergoing monitored thyroidectomy.

Methods

Medical records were collected from consecutive patients undergoing thyroid surgery before and after implementation of the protocol. A total of 748 patients intubated with EMG tube for monitored thyroidectomy by the same team were enrolled in this study. Patient allocation was based on intubation technique either conventional direct laryngoscopy (n=336) or Trachway (n=412). The intubation difficulty was assessed and analyzed.

Results

The overall incidence of difficult intubation was 4.4%. Incidence of difficult intubation was significantly lower in patients with the Trachway procedure (2.7%) than direct laryngoscopy (6.5%, P=0.01). The incidence of "unable to intubate" (>3 attempts, or change airway device or anesthesiologist) also significantly reduced from 2.3% to 0.5% after introduction of the Trachway intubating stylet (P=0.02).

Conclusions

We conclude that the incidence of difficult intubation was significantly lower with Trachway than direct laryngoscopy. The Trachway video-intubating stylet is useful and helpful to reduce EMG tube intubation difficulty for monitored thyroidectomy.

Speech therapy after thyroidectomy

Common complaints of patients who have received thyroidectomy include dysphonia (voice dysfunction) and dysphagia (difficulty swallowing). One cause of these surgical outcomes is recurrent laryngeal nerve paralysis. Many studies have discussed the effectiveness of speech therapy (e.g., voice therapy and dysphagia therapy) for improving dysphonia and dysphagia, but not specifically in patients who have received thyroidectomy. Therefore, the aim of this paper was to discuss issues regarding speech therapy such as voice therapy and dysphagia for patients after thyroidectomy. Another aim was to review the literature on speech therapy for patients with recurrent laryngeal nerve paralysis after thyroidectomy. Databases used for the literature review in this study included, PubMed, MEDLINE, Academic Search Primer, ERIC, CINAHL Plus, and EBSCO. The articles retrieved by database searches were classified and screened for relevance by using EndNote. Of the 936 articles retrieved, 18 discussed "voice assessment and thyroidectomy", 3 discussed "voice therapy and thyroidectomy", and 11 discussed "surgical interventions for voice restoration after thyroidectomy". Only 3 studies discussed topics related to "swallowing function assessment/treatment and thyroidectomy". Although many studies have investigated voice changes and assessment methods in thyroidectomy patients, few recent studies have investigated speech therapy after thyroidectomy. Additionally, some studies have addressed dysphagia after thyroidectomy, but few have discussed assessment and treatment of dysphagia after thyroidectomy.

Endoscopic screening for synchronous esophageal neoplasia among patients with incident head and neck cancer: Prevalence, risk factors, and outcomes

Esophageal squamous-cell neoplasia (ESCN) is a common second primary neoplasia found in patients with head-and-neck squamous-cell carcinoma (HNSCC). This study sought to identify the risk factors for synchronous ESCN and how they influence survival in HNSCC patient. Eight hundred and fifteen incident HNSCC patients were prospectively recruited for endoscopy screening for ESCN using white-light imaging, narrow-band imaging, Lugol chromoendoscopy, and pathological confirmation. Associated lifestyle and clinicopathological data were collected. The interquartile follow-up period cutoffs were 11.3, 20.5 and 34.9 months. 124 patients (15.2%) were diagnosed as having synchronous ESCN (66 low-grade dysplasia, 29 high-grade dysplasia, and 29 esophageal squamous-cell carcinoma). Consumption of alcohol, but not betel nut or cigarette, was significantly associated with the presence of synchronous ESCN (adjusted odds ratio [aOR] = 7.1 and 10.9 for former and current drinkers, respectively). There was an interaction between cumulative dose of alcohol consumption and alcohol flushing response on the development of ESCN. High-dose drinkers with flush response were 16.9 times more likely to have esophageal high-grade dysplasia/SCC than non-drinkers. Compared with oral cavity cancer patients, those with hypopharyngeal, laryngeal and oropharyngeal cancer were 6.8, 4.6 and 2.8 times more likely to have esophageal high-grade dysplasia/SCC. HNSCC patients with synchronous ESCN had lower overall survival than those without (p < 0.0001). In conclusion, surveillance of ESCN is strongly recommended for the high-risk subpopulation of HNSCC patients, especially drinkers who have a flush response to alcohol, and those with distant metastasis of index cancer and cancers in hypopharynx, oropharynx and larynx.

Novel quantitative analysis of autofluorescence images for oral cancer screening

OBJECTIVES

VELscope® was developed to inspect oral mucosa autofluorescence. However, its accuracy is heavily dependent on the examining physician's experience. This study was aimed toward the development of a novel quantitative analysis of autofluorescence images for oral cancer screening.

MATERIALS AND METHODS

Patients with either oral cancer or precancerous lesions and a control group with normal oral mucosa were enrolled in this study. White light images and VELscope® autofluorescence images of the lesions were taken with a digital camera. The lesion in the image was chosen as the region of interest (ROI). The average intensity and heterogeneity of the ROI were calculated. A quadratic discriminant analysis (QDA) was utilized to compute boundaries based on sensitivity and specificity.

RESULTS

47 oral cancer lesions, 54 precancerous lesions, and 39 normal oral mucosae controls were analyzed. A boundary of specificity of 0.923 and a sensitivity of 0.979 between the oral cancer lesions and normal oral mucosae were validated. The oral cancer and precancerous lesions could also be differentiated from normal oral mucosae with a specificity of 0.923 and a sensitivity of 0.970.

CONCLUSION

The novel quantitative analysis of the intensity and heterogeneity of VELscope® autofluorescence images used in this study in combination with a QDA classifier can be used to differentiate oral cancer and precancerous lesions from normal oral mucosae.

Severity of Recurrent Laryngeal Nerve Injuries in Thyroid Surgery

BACKGROUND

Few studies in the literature have reported recovery data for different types of recurrent laryngeal nerve injuries (RLNIs). This study is the first attempt to classify RLNIs and rank them by severity.

METHODS

This prospective clinical study analyzed 281 RLNIs in which a true loss of signal was identified by intraoperative neuromonitoring (IONM), and vocal cord palsy (VCP) was confirmed by a postoperative laryngoscope. For each injury type, the prevalence of VCP, the time of VCP recovery, and physical changes on nerves were analyzed. Additionally, different RLNI types were experimentally induced in a porcine model to compare morphological change.

RESULTS

The overall VCP rate in at-risk patients/nerves was 8.9/4.6 %, respectively. The distribution of RLNI types, in order of frequency, was traction (71 %), thermal (17 %), compression (4.2 %), clamping (3.4 %), ligature entrapment (1.6 %), suction (1.4 %), and nerve transection (1.4 %). Complete recovery from VCP was documented in 91 % of RLNIs. Recovery time was significantly faster in the traction group compared to the other groups (p < 0.001). The rates of temporary and permanent VCP were 98.6 and 1.4 % for traction lesion, 72 and 28 % for thermal injury, 100 and 0 % for compression injury, 50 and 50 % for clamping injury, 100 and 0 % for ligature entrapment, 100 and 0 % for suction injury, and 0 and 100 % for nerve transection, respectively. Physical changes were noted in 14 % of RLNIs in which 56 % of VCP was permanent. However, among the remaining 86 % IONM-detectable RLNIs without physical changes, only 1.2 % of VCP was permanent. A porcine model of traction lesion showed only distorted outer nerve structure, whereas the thermal lesion showed severe damage in the inner endoneurium.

CONCLUSIONS

Different RNLIs induce different morphological alterations and have different recovery outcomes. Permanent VCP is rare in lesions that are visually undetectable but detectable by IONM. By enabling early detection of RLNI and prediction of outcome, IONM can help clinicians plan intra- and postoperative treatment.

Usefulness of CBCT and guidance software for percutaneous embolization of a lymphatic leakage after thyroidectomy for cancer

Lymphatic leakage can develop as an iatrogenic complication of thoracic, cardiac, and neck surgery. The management of this complication may be challenging and involves more specialists. Percutaneous, image-guided techniques may offer two advantages: mini-invasivity and ability to image and identify the anatomy and the site of the leakage. We report a case of refractory cervical chylous leakage after thyroidectomy and lymphadenectomy for cancer that was successfully treated with an ultrasound-guided intranodal lymphangiography and a percutaneous puncture of the leak performed using CBCT as imaging guidance.

Continuous intraoperative neural monitoring of the recurrent nerves in thyroid surgery: a quantum leap in technology

The continuous intraoperative neural monitoring (CIONM) technique is increasingly acknowledged as a useful tool to recognize impending nerve injury and to abort the related manoeuvre to prevent nerve injury during thyroid surgery. CIONM provides valuable real-time information constantly, which is really useful during complex thyroid surgeries especially in the settings of unusual anatomy. Thus, CIONM overcomes the key methodological limitation inherent in intermittent nerve monitoring (IINOM); which is allowing the nerve to be at risk in between the stimulations. The clinically important combined electromyographic (EMG) event, indicative of impending recurrent laryngeal nerve (RLN) injury, prevents the majority of traction related injuries to the anatomically intact RLN enabling modification of the causative surgical manoeuvre in 80% of cases. These EMG changes can progress to loss of EMG signal with postoperative vocal cord palsy (VCP) if corrective action is not taken. As a further extension, CIONM also helps to identify intraoperative functional nerve recovery with restitution of amplitude to ≥50% of initial baseline; this allows continuing of resection of contralateral side. CIONM facilitates for early corrective action before permanent damage to the nerve has been done. CIONM is a recent but rapidly evolving technique, constantly being refined by various studies focusing on improvement in its implementation and interpretation, as well as on the elimination of the technical snags.

Safety of energy based devices for hemostasis in thyroid surgery

Energy based devices (EBD) have been developed, implemented and increasingly applied in thyroid surgery because they can provide a combined dissection and haemostatic effect. In particular, advantages of EBD have been described in terms of efficacious haemostasis, reduction of procedure-associated time, reduced incision length, less operative blood loss and transfusion need, decreased postoperative drain, pain and hospital stay. In addition, EBD are essential for endoscopic procedures. On the contrary, a potential drawback is the increased health care costs. This paper reviews relevant medical literature published on the safety of new devices for achieving hemostasis and dissection around the recurrent laryngeal nerve (RLN).

Intraoperative neural monitoring in thyroid surgery: lessons learned from animal studies

Recurrent laryngeal nerve (RLN) injury remains a significant morbidity associated with thyroid and parathyroid surgery. In the past decade, surgeons have increasingly used intraoperative neural monitoring (IONM) as an adjunct technique for localizing and identifying the RLN, detecting RLN injury, and predicting the outcome of vocal cord function. In recent years, many animal studies have investigated common pitfalls and new applications of IONM. For example, the use of IONM technology in animal models has proven valuable in studies of the electrophysiology of RLN injury. The advent of animal studies has substantially improved understanding of IONM technology. Lessons learned from animal studies have immediate clinical applications in establishing reliable strategies for preventing intraoperative RLN injury. This article gives an overview of the research progress on IONM-relevant animal models.

Safety of LigaSure in recurrent laryngeal nerve dissection-porcine model using continuous monitoring

OBJECTIVES/HYPOTHESIS

This study investigated recurrent laryngeal nerve (RLN) real-time electromyography (EMG) data to define optimal safety parameters of the LigaSure Small Jaw (LSJ) instrument during thyroidectomy.

STUDY DESIGN

Prospective animal model.

METHODS

Dynamic EMG tracings were recorded from 32 RLNs (16 piglets) during various applications of LSJ around using continuous electrophysiologic monitoring. At varying distances from the RLN, the LSJ was activated (activation study). The LSJ was also applied to the RLN at timed intervals after activation and after a cooling maneuver through placement on the sternocleidomastoid muscle (cooling study).

RESULTS

In the activation study, there was no adverse EMG event at 2 to 5 mm distance (16 RLNs, 96 tests). In the cooling study, there was no adverse EMG event after 2-second cooling time (16 RLNs, 96 tests) or after the LSJ cooling maneuver on the surrounding muscle before reaching the RLNs (8 RLNs, 24 tests).

CONCLUSION

Based on EMG functional assessment, the safe distance for LSJ activation was 2 mm. Further LSJ-RLN contact was safe if the LSJ was cooled for more than 2 seconds or cooled by touch muscle maneuver. The LSJ should be used with these distance and time parameters in mind to avoid RLN injury.

LEVEL OF EVIDENCE

N/A. Laryngoscope, 127:1724-1729, 2017.

The electrophysiology of thyroid surgery: electrophysiologic and muscular responses with stimulation of the vagus nerve, recurrent laryngeal nerve, and external branch of the superior laryngeal nerve

OBJECTIVES/HYPOTHESIS

Correlation of physiologically important electromyographic (EMG) waveforms with demonstrable muscle activation is important for the reliable interpretation of evoked waveforms during intraoperative neural monitoring (IONM) of the vagus nerve, recurrent laryngeal nerve (RLN), and external branch of the superior laryngeal nerve (EBSLN) in thyroid surgery.

STUDY DESIGN

Retrospective chart review.

METHODS

Data were reviewed retrospectively for thyroid surgery patients with laryngeal nerve IONM from January to December, 2015. EMG responses to monopolar stimulation of the vagus/RLN and EBSLN were recorded in bilateral vocalis, cricothyroid (CTM), and strap muscles using endotracheal tube-based surface and intramuscular hook electrodes, respectively. Target muscles for vagal/RLN and EBSLN stimulation were the ipsilateral vocalis and CTM, respectively. All other recording channels were nontarget muscles.

RESULTS

Fifty surgical sides were identified in 37 subjects. All target muscle mean amplitudes were significantly higher than in nontarget muscles. With vagal/RLN stimulation, target ipsilateral vocalis mean amplitude was 1,095.7 μV (mean difference range = -814.1 to -1,078 μV, P < .0001). For EBSLN stimulation, target ipsilateral CTM mean amplitude was 6,379.3 μV (mean difference range = -6,222.6 to -6,362.3 μV, P < .0001). Target muscle large-amplitude EMG responses correlated with meaningful visual or palpable muscular responses, whereas nontarget EMG responses showed no meaningful muscle activation.

CONCLUSIONS

Target and nontarget laryngeal muscles are differentiated based on divergence of EMG response directly correlating with presence or absence of visual and palpable muscle activation. Low-amplitude EMG waveforms in nontarget muscles with neural stimulation can be explained by the concept of far-field artifactual waveforms and do not correspond to a true muscular response. The surgeon should be aware of these nonphysiologic waveforms when interpreting and applying IONM during thyroid surgery.

LEVEL OF EVIDENCE

4 Laryngoscope, 127:764-771, 2017.

Recurrent laryngeal nerve injury in thyroid surgery: Clinical pathways and resources consumption

BACKGROUND

The impact of recurrent laryngeal nerve (RLN) injury management in thyroid surgery seems to be relevant to patients, National Healthcare System (NHS), and society.

METHODS

We studied resource consumption in the management of patients with RLN injury versus noninjured patients investigating 3 perspectives (patients, NHS, and society) in 5 clinical pathways.

RESULTS

Direct medical costs supported by the NHS range from a minimum of euro (€) 79.46 to a maximum of € 3261.95. From the patient's perspective, the direct medical costs supported by the patient increased from a minimum of € 3.60 to a maximum of € 499.45. Productivity losses were accounted in € 156 per day per patient. From the NHS perspective, the percentage increase ranged from 43.25% to 98.14%. From the patient's perspective, it ranged from 51.52% to 80.60%.

CONCLUSION

The analysis shows a significant economic impact of RLN injury management, which varies depending on the damage, duration, and severity. © 2016 Wiley Periodicals, Inc. Head Neck 38: 1708-1716, 2016.

Posterior cricoarytenoid muscle electrophysiologic changes are predictive of vocal cord paralysis with recurrent laryngeal nerve compressive injury in a canine model

OBJECTIVES/HYPOTHESIS

Injury to the recurrent laryngeal nerve (RLN) is a dreaded complication of endocrine surgery. Intraoperative neural monitoring (IONM) has been increasingly utilized to assess the functional status of the RLN. Although the posterior cricoarytenoid muscle (PCA) is innervated by the RLN as the abductor of the larynx, PCA electromyography (EMG) is infrequently recorded during IONM and PCA activity after RLN compressive injury remains poorly characterized.

STUDY DESIGN

Single-subject prospective animal study.

METHODS

We employed a canine model to identify postcricoid EMG correlates of postoperative vocal cord paralysis (VCP). Postcricoid electrode recordings were obtained before and after compressive RLN injury associated with VCP.

RESULTS

Normative postcricoid recordings revealed mean amplitude of 1288 microvolt (μV) and latency of 8.2 millisecond (ms) with maximum (1 milliamp [mA]) vagal stimulation, and mean amplitude of 1807 μV and latency of 3.5 ms with maximum (1 mA) RLN stimulation. Following injury that was associated with VCP, there was 62.1% decrement in postcricoid EMG amplitude with maximum vagal stimulation and 80% decrement with maximum RLN stimulation. Threshold stimulation of the vagus increased by 23%, and there was a corresponding 42% decrease in amplitude. For RLN stimulation, latency increased by 17.3% following injury, whereas threshold stimulation increased by 61% with 35.5% decrement in EMG amplitude. Thus, if RLN amplitude decreases by ≥ 80%, with absolute amplitude of ≤ 300 μV or less and latency increase of ≥ 10%, RLN injury is likely associated with VCP.

CONCLUSION

Our results predict postoperative VCP based on postcricoid electromyographic IONM and may guide surgical decision making.

LEVEL OF EVIDENCE

NA Laryngoscope, 126:2744-2751, 2016.

Reversal of rocuronium-induced neuromuscular blockade by sugammadex allows for optimization of neural monitoring of the recurrent laryngeal nerve

OBJECTIVES/HYPOTHESIS

The use of neuromuscular blocking agent may effect intraoperative neuromonitoring (IONM) during thyroid surgery. An enhanced neuromuscular-blockade (NMB) recovery protocol was investigated in a porcine model and subsequently clinically applied during human thyroid neural monitoring surgery.

STUDY DESIGN

Prospective animal and retrospective clinical study.

METHODS

In the animal experiment, 12 piglets were injected with rocuronium 0.6 mg/kg and randomly allocated to receive normal saline, sugammadex 2 mg/kg, or sugammadex 4 mg/kg to compare the recovery of laryngeal electromyography (EMG). In a subsequent clinical application study, 50 patients who underwent thyroidectomy with IONM followed an enhanced NMB recovery protocol-rocuronium 0.6 mg/kg at anesthesia induction and sugammadex 2 mg/kg at the operation start. The train-of-four (TOF) ratio was used for continuous quantitative monitoring of neuromuscular transmission.

RESULTS

In our porcine model, it took 49 ± 15, 13.2 ± 5.6, and 4.2 ± 1.5 minutes for the 80% recovery of laryngeal EMG after injection of saline, sugammadex 2 mg/kg, and sugammadex 4 mg/kg, respectively. In subsequent clinical human application, the TOF ratio recovered from 0 to >0.9 within 5 minutes after administration of sugammadex 2 mg/kg at the operation start. All patients had positive and high EMG amplitude at the early stage of the operation, and intubation was without difficulty in 96% of patients.

CONCLUSIONS

Both porcine modeling and clinical human application demonstrated that sugammadex 2 mg/kg allows effective and rapid restoration of neuromuscular function suppressed by rocuronium. Implementation of this enhanced NMB recovery protocol assures optimal conditions for tracheal intubation as well as IONM in thyroid surgery.

LEVEL OF EVIDENCE

NA.