Incidence and predictors of thermal oesophageal and vagus nerve injuries in Ablation Index-guided high-power-short-duration ablation of atrial fibrillation: a prospective study.

AIMS: High-power-short-duration (HPSD) ablation is an effective treatment for atrial fibrillation but poses risks of thermal injuries to the oesophagus and vagus nerve. This study aims to investigate incidence and predictors of thermal injuries, employing machine learning. METHODS AND RESULTS: A prospective observational study was conducted at Leipzig Heart Centre, Germany, excluding patients with multiple prior ablations. All patients received Ablation Index-guided HPSD ablation and subsequent oesophagogastroduodenoscopy. A machine learning algorithm categorized ablation points by atrial location and analysed ablation data, including Ablation Index, focusing on the posterior wall. The study is registered in clinicaltrials.gov (NCT05709756). Between February 2021 and August 2023, 238 patients were enrolled, of whom 18 (7.6%; nine oesophagus, eight vagus nerve, one both) developed thermal injuries, including eight oesophageal erythemata, two ulcers, and no fistula. Higher mean force (15.8 ± 3.9 g vs. 13.6 ± 3.9 g, P = 0.022), ablation point quantity (61.50 ± 20.45 vs. 48.16 ± 19.60, P = 0.007), and total and maximum Ablation Index (24 114 ± 8765 vs. 18 894 ± 7863, P = 0.008; 499 ± 95 vs. 473 ± 44, P = 0.04, respectively) at the posterior wall, but not oesophagus location, correlated significantly with thermal injury occurrence. Patients with thermal injuries had significantly lower distances between left atrium and oesophagus (3.0 ± 1.5 mm vs. 4.4 ± 2.1 mm, P = 0.012) and smaller atrial surface areas (24.9 ± 6.5 cm2 vs. 29.5 ± 7.5 cm2, P = 0.032). CONCLUSION: The low thermal lesion's rate (7.6%) during Ablation Index-guided HPSD ablation for atrial fibrillation is noteworthy. Machine learning based ablation data analysis identified several potential predictors of thermal injuries. The correlation between machine learning output and injury development suggests the potential for a clinical tool to enhance procedural safety.

Pulmonary vagus nerve transection for chronic cough after video-assisted lobectomy: a randomized controlled trial.

BACKGROUND: Chronic cough is common after lobectomy. Vagus nerves are part of the cough reflex. Accordingly, transection of the pulmonary branches of vagus nerve may prevent chronic cough. And there are no clear recommendations on the management of the pulmonary branches of vagus in any thoracic surgery guidelines. METHODS: This is a single-center, randomized controlled trial. Adult patients undergoing elective video-assisted thoracoscopic lobectomy and lymphadenectomy were randomized at a 1:1 ratio to undergo a sham procedure (control group) or transection of the pulmonary branches of the vagus nerve that innervate the bronchial stump plus the caudal-most large pulmonary branch of the vagus nerve. The primary outcome was the rate of chronic cough, as assessed at 3 months after surgery in the intent-to-treat population. RESULTS: Between 1 February 2020 and 1 August 2020, 116 patients (59.6±10.1 years of age; 45 men) were randomized (58 in each group). All patients received designated intervention. The rate of chronic cough at 3 months was 19.0% (11/58) in the vagotomy group versus 41.4% (24/58) in the control group (OR=0.332, 95% CI: 0.143-0.767; P =0.009). In the 108 patients with 2-year assessment, the rate of persistent cough was 12.7% (7/55) in the control and 1.9% (1/53) in the vagotomy group ( P =0.032). The two groups did not differ in postoperative complications and key measures of pulmonary function, for example, maximal voluntary ventilation, diffusing capacity of the lungs for carbon monoxide, and forced expiratory volume. CONCLUSION: Transecting the pulmonary branches of vagus nerve that innervate the bronchial stump plus the caudal-most large pulmonary branch decreased the rate of chronic cough without affecting pulmonary function in patients undergoing video-assisted lobectomy and lymphadenectomy.

Pulmonary vein isolation-induced vagal nerve injury and gastric motility disorders detected by electrogastrography: The side effects of pulmonary vein isolation in atrial fibrillation (SEPIA) study.

INTRODUCTION: Safety of pulmonary vein isolation (PVI) has been established in clinical studies. However, despite prevention efforts the incidence of damage to (peri)-esophageal tissue has not decreased, and the pathophysiology is incompletely understood. Damage to vagal nerve branches may be involved in lesion progression to atrio-esophageal fistula. Using electrogastrography, we assessed the incidence of periesophageal vagal nerve injury (VNI) following atrial fibrillation ablation and its association with procedural parameters and endoscopic results. METHODS: Patients were studied using electrogastrography, endoscopy, and endoscopic ultrasound before and after cryoballoon (CB) or radiofrequency (RF) PVI. The incidence of ablation-induced neuropathic pattern (indicating VNI) in pre- and postprocedural electrogastrography was assessed and correlated with endoscopic results and ablation data. RESULTS: Between February 2021 und January 2022, 85 patients (67 ± 10 years, 53% male) were included, 33 were treated with CB and 52 with RF (38 with moderate power moderate duration [25-30 W] and 14 with high power short duration [50 W]). Ablation-induced VNI was detected in 27/85 patients independent of the energy form. Patients with VNI more frequently had postprocedural endoscopically detected pathology (8% mucosal esophageal lesions, 36% periesophageal edema, 33% food retention) but there was incomplete overlap. Pre-existing esophagitis increased the likelihood of VNI. Ablation data and esophageal temperature data did not predict VNI. CONCLUSION: PVI-induced VNI is quite common and independent of ablation energy source. VNI is part of (peri)-esophageal damage and only partially overlaps with endoscopic findings. VNI-associated acidic reflux may be involved in the complex pathophysiology of esophageal lesion progression to fistula.

Impact of the Hepatic Branch of the Vagus Nerve Transection in Laparoscopic Sleeve Gastrectomy for Patients with Obesity and Type 2 Diabetes Mellitus.

BACKGROUND: An increase in gastroesophageal reflux disease (GERD) after laparoscopic sleeve gastrectomy (LSG) has been reported, and concomitant hiatal hernia repair (HHR) during LSG is expected to reduce the incidence of post-LSG GERD. In HHR, the hepatic branch of the vagus nerve is anatomically transected. Recent experimental animal models suggest that vagotomy may affect glycemic control and weight loss through a neuroendocrine response. OBJECTIVES: To examine whether LSG with/without hepatic branch vagotomy (HV) has a clinical impact on glycemic control in patients with obesity and type 2 diabetes mellitus (T2DM). Furthermore, the impact on weight loss and post-LSG GERD were evaluated. METHODS: A total of 204 Japanese patients with obesity and T2DM, who underwent LSG and completed 1-year follow-up, were retrospectively analyzed. Operative outcomes, weight loss, glycemic, and GERD-related parameters were compared between the LSG/HHR/HV group (n = 89) and the LSG group (n = 115). RESULTS: There was no significant difference in the background factors in terms of anthropometric and T2DM-related parameters between the groups. The median operation times in the LSG/HHR/HV and LSG groups were 133 and 124 minutes, respectively (p = 0.236). At 1 year, the diabetes remission rate, HbA1c, fasting glucose, and C-peptide levels were all comparable between the groups. The weight loss effect was also comparable. The patients in the LSG/HHR/HV group achieved significant improvement and prevention of GERD and hiatus hernia (p < 0.001). CONCLUSION: HV does not appear to have a clinical impact on glycemic control and weight loss. Concomitant HHR with LSG serves to reduce post-LSG GERD.

Anatomical variation and distribution of the vagus nerve in the esophageal hiatus: a cross-sectional study of post-mortem cases in Uganda.

PURPOSE: Vagus nerve injuries during gastroesophageal surgery may cause significant symptoms due to loss of vagal anti-inflammatory and neuromodulator function. Many previous studies have shown high anatomical variability of the vagus nerve at the esophageal hiatus, but information on its variability in Uganda specifically and Africa in general is scanty. This study provides a reliable and detailed description of the anatomical variation and distribution of the vagus nerve in the esophageal hiatus region of post-mortem cases in Uganda. METHODS: This was an analytical cross-sectional survey of 67 unclaimed post-mortem cases. Data collection used a pretested data collection form. Data were entered into Epi-Info version 6.0 data base then exported into STATA software 13.0 for analysis. RESULTS: The pattern of the anterior vagal trunk structures at the esophageal hiatus was: single trunk [65.7%]; biplexus [20.9%]; triplexus [8.9%] and double-but-not-connected trunks [4.5%]. The pattern of the posterior trunk structures were: single trunk [85.1%]; biplexus 10.4% and triplexus [4.5%]. There was no statistically significant gender difference in the pattern of vagal fibres. There was no major differences in the pattern from comparable British studies. CONCLUSION: The study confirmed high variability in the distribution of the vagus nerve at the esophageal hiatus, unrelated to gender differences. Surgeons must consider and identify variants of vagal innervation when carrying out surgery at the gastroesophageal junction to avoid accidental vagal injuries. Published surgical techniques for preserving vagal function are valid in Uganda.

Preservation of hepatic branch of the vagus nerve reduces the risk of gallstone formation after gastrectomy.

BACKGROUND: Injury to the vagus nerve has been proposed to be associated with occurrence of gallstones after gastrectomy. We investigated the effect of preservation of hepatic branch of the vagus nerve on prevention of gallstones during laparoscopic distal (LDG) and pylorus-preserving gastrectomy (LPPG). METHODS: Preservation of the vagus nerve was reviewed of cT1N0M0 gastric cancer patients underwent LDG (n = 323) and LPPG (n = 144) during 2016-2017. Presence of gallstones was evaluated by ultrasonography (US) and computed tomography (CT). Incidences of gallstones were compared between the nerve preserved (h-DG, h-PPG) group and sacrificed (s-DG, s-PPG) group. Clinicopathological features were also compared. RESULTS: The 3-year cumulative incidence of gallstones was lower in the h-DG (2.7%, n = 85) than the s-DG (14.6%, n = 238) (p = 0.017) and lower in the h-PPG (1.6%, n = 123) than the s-PPG (12.9%, n = 21) (p = 0.004). Overall postoperative complication rate was similar between the h-DG and s-DG (p = 0.861) as well as between the h-PPG and s-PPG (p = 0.768). The number of retrieved lymph nodes station #1 and 3-year recurrence-free survival were not significantly different between the preserved group and sacrificed group. Injury to the vagus nerve (p = 0.001) and high body mass index (BMI) (≥ 27.5 kg/m2) (p = 0.040) were found to be independent risk factors of gallstone formation in multivariate analysis. CONCLUSIONS: Preservation of hepatic branch of the vagus nerve can be recommended for LDG as well as LPPG of early gastric cancer patients to reduce postoperative gallstone formation.

Ex vivo study of vagal branches at risk for iatrogenic injury during laryngoplasty in horses.

OBJECTIVE: To localize vagal branches within the surgical field of laryngoplasty and identify potentially hazardous surgical steps. STUDY DESIGN: Observational cadaveric study. SAMPLE POPULATION: Five equine head-neck specimens and four entire equine cadavers. METHODS: Dissection of the pharyngeal region from a surgical perspective. Neuronal structures were considered at risk if touched or if the distance to instruments was less than 5 mm. RESULTS: The branches of the pharyngeal plexus (PP) supplying the cricopharyngeal muscle (PPcr), the thyropharyngeal muscle (PPth), and the esophagus (PPes) were identified in the surgical field in nine of nine, five of nine, and one of nine specimens, respectively. The internal branch of the cranial laryngeal nerve (ibCLN) was identified within the carotid sheath in six of nine specimens. The external branch of the cranial laryngeal nerve (ebCLN) was identified close to the septum of the caudal constrictors in nine of nine specimens. The blade of the tissue retractor compressed the ibCLN in six of six, the ebCLN in four of six, the PPcr in six of six, the PPth in two of three, and the PPes in two of two specimens in which the respective nerves were identified after further dissection. Surgical exploration of the dorsolateral aspect of the pharynx and the incision of the septum of the caudal constrictors harmed the ebCLN in nine of nine, PPcr in seven of nine, and PPth in four of eight specimens. CONCLUSION: Several vagal branches were located in the surgical field and must be considered at risk because of their location. CLINICAL SIGNIFICANCE: Use of the tissue retractor, dissection over the pharynx, and dissection of the septum of the caudal constrictors involve a risk to damage vagal branches.

Reduction in Pulmonary Vein Stenosis and Collateral Damage With Pulsed Field Ablation Compared With Radiofrequency Ablation in a Canine Model.

BACKGROUND: Pulmonary vein (PV) stenosis is a highly morbid condition that can result after catheter ablation for PV isolation. We hypothesized that pulsed field ablation (PFA) would reduce PV stenosis risk and collateral injury compared with irrigated radiofrequency ablation (IRF). METHODS: IRF and PFA deliveries were randomized in 8 dogs with 2 superior PVs ablated using one technology and 2 inferior PVs ablated using the other technology. IRF energy (25-30 W) or PFA was delivered (16 pulse trains) at each PV in a proximal and in a distal site. Contrast computed tomography scans were collected at 0, 2, 4, 8, and 12-week (termination) time points to monitor PV cross-sectional area at each PV ablation site. RESULTS: Maximum average change in normalized cross-sectional area at 4-weeks was -46.1±45.1% post-IRF compared with -5.5±20.5% for PFA (P≤0.001). PFA-treated targets showed significantly fewer vessel restrictions compared with IRF (P≤0.023). Necropsy showed expansive PFA lesions without stenosis in the proximal PV sites, compared with more confined and often incomplete lesions after IRF. At the distal PV sites, only IRF ablations were grossly identified based on focal fibrosis. Mild chronic parenchymal hemorrhage was noted in 3 left superior PV lobes after IRF. Damage to vagus nerves as well as evidence of esophagus dilation occurred at sites associated with IRF. In contrast, no lung, vagal nerve, or esophageal injury was observed at PFA sites. CONCLUSIONS: PFA significantly reduced risk of PV stenosis compared with IRF postprocedure in a canine model. IRF also caused vagus nerve, esophageal, and lung injury while PFA did not.

Tapia Syndrome After Cervical Laminoplasty: A Case Report and Review of the Literature.

BACKGROUND: Tapia syndrome is a rare complication of surgical positioning with resulting unilateral cranial nerve X and XII deficits that may provide diagnostic challenges in the perioperative period. Timely diagnosis will facilitate obtaining the necessary supportive care while preventing unnecessary workup and procedures. CASE DESCRIPTION: The following case report illustrates a patient that developed Tapia syndrome immediately after a posterior cervical laminoplasty with eventual resolution of symptoms. A review of the literature was also undertaken for comparison. CONCLUSIONS: Tapia syndrome can occur with a variety of surgeries, but appear to be most common in surgeries of the posterior cervical spine in the neurosurgical literature. It is theorized that flexed head position common among posterior cervical procedures makes patients more prone to Tapia syndrome in these cases. The ideal management remains poorly defined in the literature. The time course and resolution of neurologic deficits support a transient neuropraxic mechanism in most cases, though some patients do suffer permanent deficits.

An Unusual Cervical Injury Caused by Accidental Electrical Burns.

High-voltage electrocution is mostly unintentional, and it is associated with significant morbidity and mortality due to severe tissue damages. The present report describes an atypical electrocution with multiple victims and a fatal outcome of a 48-year-old man due to unusual neck injuries caused by accidental electrical burns.

What Happens in (the) Vagus, Stays in (the) Vagus.

Many cardiothoracic operations put the nerves of the thorax at risk. In fact, nerve injuries are one of the most common reasons cited in malpractice cases brought against cardiothoracic surgeons. While all physicians learn about the nerves of the thorax during anatomy courses in medical school, little is written about avoiding injury to these important nerves in the cardiothoracic surgical literature. We have, therefore, embarked on an effort to collate information on the anatomy, function, and protection of these nerves, with which every cardiothoracic surgeon should be familiar. We will call this effort "The Nerve Protection Project." Acknowledging that the material to be covered is considerable, we will break the project into a series of editorials. The first installment in this series will address the anatomy and function of the vagus nerve and the protection of this nerve and its branches during cardiothoracic surgical operations, as they are in harm's way during many of these procedures.

Activation of a nerve injury transcriptional signature in airway-innervating sensory neurons after lipopolysaccharide-induced lung inflammation.

The lungs and the immune and nervous systems functionally interact to respond to respiratory environmental exposures and infections. The lungs are innervated by vagal sensory neurons of the jugular and nodose ganglia, fused together in smaller mammals as the jugular-nodose complex (JNC). Whereas the JNC shares properties with the other sensory ganglia, the trigeminal (TG) and dorsal root ganglia (DRG), these sensory structures express differential sets of genes that reflect their unique functionalities. Here, we used RNA sequencing (RNA-seq) in mice to identify the differential transcriptomes of the three sensory ganglia types. Using a fluorescent retrograde tracer and fluorescence-activated cell sorting, we isolated a defined population of airway-innervating JNC neurons and determined their differential transcriptional map after pulmonary exposure to lipopolysaccharide (LPS), a major mediator of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) after infection with gram-negative bacteria or inhalation of organic dust. JNC neurons activated an injury response program, leading to increased expression of gene products such as the G protein-coupled receptor Cckbr, inducing functional changes in neuronal sensitivity to peptides, and Gpr151, also rapidly induced upon neuropathic nerve injury in pain models. Unique JNC-specific transcripts, present at only minimal levels in TG, DRG, and other organs, were identified. These included TMC3, encoding for a putative mechanosensor, and urotensin 2B, a hypertensive peptide. These findings highlight the unique properties of the JNC and reveal that ALI/ARDS rapidly induces a nerve injury-related state, changing vagal excitability.

Transient postsurgical gastroparesis is accompanied by reversible changes of the cervical vagus nerve's morphology after neck dissection - an ultrasound study.

AIMS: During neck dissection (ND), the vagus nerve (VN) may be exposed to manipulation together with common carotid artery and internal jugular vein. The postsurgical gastroparesis was previous related to the VN injury. The aim of our study was to evaluate by ultrasound the VN changes in patients with unilateral and bilateral ND and to establish if there is a relationship between postoperative findings of VN and postsurgical gastroparesis. MATERIAL AND METHODS: Seventeen patients in which 30 ND (4 unilateral and 13 bilateral) were performed, were enrolled in the study. The VN's area and diameter were measured preoperative (baseline), one week (T1) and one month (T2) postoperative. Gastrointestinal symptoms were evaluated at T1 and T2 phases using the patient assessment of the upper gastrointestinal symptom severity index (PAGI-SYM). RESULTS: There was a statistical difference between area and diameters of VN between T1 and baseline (p<0.001), and T1 and T2 phases (p<0.001), respectively. No statistical differences were detected at baseline and T2 phases in areas (p=0.934) and diameters (p>0.999). Gastrointestinal symptoms, found at the T1 phase regressed at T2 phase, were correlated with VN area and diameter changes (p<0.001). CONCLUSIONS: VN ultrasound clearly showed the transient dimensional changes of VN caused by manipulation in ND, which may lead to temporary gastrointestinal symptoms due to reversible dysfunction of VN.

Roux­en­Y gastric bypass surgery triggers rapid DNA fragmentation in vagal afferent neurons in rats.

Previous studies have shown that Roux­en­Y gastric bypass (RYGB), one of the most effective weight loss treatments for obesity, results in neurodegenerative responses in vagal afferent gut­brain connection reflected by microglia activation and reduced sensory input to the nucleus tractus solitarius (NTS). However, it is not known whether RYGB­induced microglia activation is the cause or an effect of the reported neuronal damage. Therefore, the aim of this study was to establish the order of neurodegenerative responses in vagal afferents after RYGB in the nodose ganglia (NG) and NTS in male and female rats. Sprague­Dawley rats were fed regular chow or an energy­dense diet for two weeks followed by RYGB or sham surgery. Twenty­four hours later, animals were sacrificed and NG and NTS were collected. Neuronal cell damage was determined by TUNEL assay. Microglia activation was determined by quantifying the fluorescent staining against the ionizing calcium adapter­binding molecule 1. Reorganization of vagal afferents was evaluated by fluorescent staining against isolectin 4. Results of the study revealed significantly increased DNA fragmentation in vagal neurons in the NG when observed at 24 h after RYGB. The surgery did not produce rapid changes in the density of vagal afferents and microglia activation in the NTS. These data indicate that decreased density of vagal afferents and increased microglia activation in the NTS likely ensue as a res ult of RYGB­induced neuronal damage.

Delayed onset vagus nerve paralysis after occipital condyle fracture in a horse.

Occipital condylar fractures (OCFs) causing delayed onset lower cranial nerve paralysis (LCNPs) are rare. We present a 7-year-old Friesian horse with delayed onset dysphagia caused by vagus nerve (CNX) paralysis and suspicion of glossopharyngeal nerve (CNIX) paralysis developed several days after a minor head injury. Endoscopic examination revealed right laryngeal hemiplegia and intermittent dorsal displacement of the soft palate. An area of submucosal hemorrhage and bulging was appreciated over the dorsal aspect of the medial compartment of the right guttural pouch. Radiological examination of the proximal cervical region showed rotation of the atlas and the presence of a large bone fragment dorsal to the guttural pouches. Occipital condyle fracture with delayed onset cranial nerve paralysis was diagnosed. Delayed onset cranial nerve paralysis causing dysphagia might be a distinguishable sign of OCF in horses. Delayed onset dysphagia after head injury should prompt equine clinicians to evaluate the condition of the atlanto-occipital articulation and skull base.

A novel approach to neurologic function sparing surgical management of vagal schwannomas: Continuous intraoperative nerve monitoring of the laryngeal adductor reflex.

BACKGROUND: Vagal schwannomas are rare, benign tumors of the head and neck. Nerve damage during surgical resection is associated with significant morbidity. A new technique of continuous intraoperative nerve monitoring (IONM) that allows for real-time intraoperative feedback has recently been used for thyroid and cervical spine surgeries but has not previously been used in vagal schwannoma surgery. METHODS: Case series of three patients who underwent vagal schwannoma excision utilizing this novel IONM technique. The recurrent laryngeal and vagus nerves were monitored via the laryngeal adductor reflex (LAR) using an electromyographic endotracheal tube. RESULTS: Three patients with suspected vagal schwannomas were treated surgically using the intracapsular enucleation approach with a combination of intermittent IONM and continuous IONM of the LAR. CONCLUSION: This combination of continuous and intermittent IONM can be used to preserve vagal laryngeal innervation and function and may represent the future standard of care for vagal schwannoma excision.

Effect of Tailored Perigastric Lymph Node Dissection on Gastric Motility in a Canine Model.

BACKGROUND: Combination laparoscopic lymph node (LN) dissection and endoscopic resection is a promising treatment for early gastric cancer. However, LN dissection could cause nerve injury and deterioration of motility in the preserved stomach. This experimental study aims to evaluate changes in gastric motility after tailored perigastric regional lymph node dissection without gastrectomy. MATERIALS AND METHODS: We identified four most frequently involved LN combinations considering tumor location from retrospective reviews of 4697 gastrectomy patients. We randomly assigned 55 dogs to five groups: control (laparotomy only) and four experimental groups with LN dissection without gastrectomy: group 1 (LNs 3, 7, and 8), group 2 (LNs 3, 4, and 6), group 3 (LNs 1, 3, and 7), and group 4 (LNs 3, 4, and 11). Gastric emptying time (GET) was measured using barium-impregnated polyethylene spheres. GET50 and GET75 were the time points when 50% and 75% of the markers, respectively, had emptied from the stomach. RESULTS: On postoperative days (PODs) 2 and 3, GET50, GET75, and proportion of GET50 <4 h in groups 1 and 2 were comparable with controls. However, group 3 showed delayed GET50 and GET75, and groups 3 and 4 demonstrated significantly smaller proportions of GET50 <4 h compared with controls on PODs 2 and 3. This effect resolved by POD 6 and there were no significant differences in GET50, GET75, or proportion of GET50 <4 h between the groups. CONCLUSIONS: Tailored perigastric LN resection without gastrectomy was feasible and acceptable in terms of postoperative motility in the preserved stomach.

Resection of a Superior Mediastinal Mature Teratoma Using Intraoperative Neural Monitoring.

A 33-year-old woman presented with a right cervical mass. Contrast computed tomography showed a multilocular tumor with a clear border and heterogeneous contents including fat and calcification. The tumor was located adjacent to the vagus and recurrent nerves. To avoid injury of these nerves, we resected the tumor through a median sternotomy and right cervical lateral incision. Intraoperative neural monitoring was performed using an NIM TriVantage EMG tube (Medtronic, Minneapolis, MN). After the surgery, no neuropathy such as hoarseness was recognized. Pathological diagnosis showed a benign mature teratoma. Intraoperative neural monitoring is useful for superior mediastinal surgery around the vagus and recurrent nerves.

Vagal schwannomas of the head and neck: A comprehensive review and a novel approach to preserving vocal cord innervation and function.

BACKGROUND: Schwannomas, benign tumors arising from neurolemmocytes, are the most common type of peripheral nerve tumors. Extracranial schwannomas are most often found in the parapharyngeal space, commonly involving the vagus nerve to cervical sympathetic trunk. Vagal schwannomas present several unique clinical and therapeutic challenges. METHODS: A comprehensive literature review was conducted on 197 articles reporting 235 cases of cervical vagal schwannomas. Presenting symptoms, treatment approach, and postoperative outcomes were recorded and analyzed. RESULTS: Vagal schwannomas commonly present as asymptomatic neck masses. When they become symptomatic, surgical resection is the standard of care. Gross total resection is associated with higher postoperative morbidity compared to subtotal resection. Initial reports using intraoperative nerve monitoring have shown improved nerve preservation. Recurrence rates are low. CONCLUSION: The combination of intermittent nerve mapping with novel continuous vagal nerve monitoring techniques may reduce postoperative morbidity and could represent the future standard of care for vagal schwannoma treatment.