Preservation of the celiac branch of the vagus nerve reduces the incidence of postoperative diarrhea in gastric cancer: a cohort study.

BACKGROUND: To investigate the short-term and long-term outcomes of preserving the celiac branch of the vagus nerve during laparoscopic distal gastrectomy. METHODS: A total of 149 patients with prospective diagnosis of gastric cancer who underwent laparoscopic-assisted distal gastrectomy (LADG) combined with Billroth-II anastomosis and D2 lymph node dissection between 2017 and 2018 were retrospectively analyzed. The patients were divided into the preserved LADG group (P-LADG, n = 56) and the resected LADG group (R-LADG, n = 93) according to whether the vagus nerve celiac branch was preserved. We selected 56 patients (P-LADG, n = 56) with preservation of the celiac branch of the vagus nerve and 56 patients (R-LADG, n = 56) with removal of the celiac branch of the vagus nerve by propensity-matched score method. Postoperative nutritional status, weight change, short-term and long-term postoperative complications, and gallstone formation were evaluated in both groups at 5 years of postoperative follow-up. The status of residual gastritis and bile reflux was assessed endoscopically at 12 months postoperatively. RESULTS: The incidence of diarrhea at 5 years postoperatively was lower in the P-LADG group than in the R-LADG group (p < 0.05). In the multivariate logistic analysis, the removal of vagus nerve celiac branch was an independent risk factor for the occurrence of postoperative diarrhea (odds ratio = 3.389, 95% confidential interval = 1.143-10.049, p = 0.028). In the multivariate logistic analysis, the removal of vagus nerve celiac branch was an independent risk factor for the occurrence of postoperative diarrhea (odds ratio = 4.371, 95% confidential interval = 1.418-13.479, p = 0.010). CONCLUSIONS: Preservation of the celiac branch of the vagus nerve in LADG reduced the incidence of postoperative diarrhea postoperatively in gastric cancer. TRIAL REGISTRATION: This study was registered with the Ethics Committee of the First Affiliated Hospital of Dalian Medical University in 2014 under the registration number: LCKY2014-04(X).

Vagus nerve signal has an inhibitory influence on the development of peritoneal metastasis in murine gastric cancer.

The vagus nerve is the only pathway for transmitting parasympathetic signals between the brain and thoracoabdominal organs, thereby exhibiting anti-inflammatory functions through the cholinergic anti-inflammatory pathway. Despite often being resected during lymph node dissection in upper gastrointestinal cancer surgery, the impact of vagotomy on postoperative outcomes in gastric cancer patients remains unclear. Sub-diaphragmatic vagotomy was performed on C57BL/6 mice. Three weeks later, syngeneic murine gastric cancer cell line YTN16P was injected into the peritoneal cavity, and the number of peritoneal metastases (PM) on the mesentery and omentum compared with control mice. The phenotypes of immune cells in peritoneal lavage and omental milky spots one day after tumor inoculation were analyzed using flow cytometry and immunohistochemistry. Intraperitoneal transfer of 3 × 105 YTN16P significantly increased the number of metastatic nodules on the mesentery in the vagotomy group compared to the control group. The omental metastasis grade was also significantly higher in the vagotomy group. Phenotypic analysis of immune cells in peritoneal lavage did not reveal significant differences after vagotomy. However, vagotomized mice exhibited a notable increase in milky spot area, with a higher presence of cytokeratin(+) tumor cells, F4/80(+) macrophages, and CD3(+) T cells. Vagus nerve signaling appears to regulate the immune response dynamics within milky spots against disseminated tumor cells and inhibits the development of PM. Preserving the vagus nerve may offer advantages in advanced gastric cancer surgery to reduce peritoneal recurrence.

Implantation Surgery for Abdominal Vagus Nerve Stimulation and Recording Studies in Awake Rats.

Abdominal vagus nerve stimulation (VNS) can be applied to the subdiaphragmatic branch of the vagus nerve of rats. Due to its anatomical location, it does not have any respiratory and cardiac off-target effects commonly associated with cervical VNS. The lack of respiratory and cardiac off-target effects means that the intensity of stimulation does not need to be lowered to reduce side effects commonly experienced during cervical VNS. Few recent studies demonstrate the anti-inflammatory effects of abdominal VNS in rat models of inflammatory bowel disease, rheumatoid arthritis, and glycemia reduction in a rat model of type 2 diabetes. Rat is a great model to explore the potential of this technology because of the well-established anatomy of the vagus nerve, the large size of the nerve that allows easy handling, and the availability of many disease models. Here, we describe the methods for cleaning and sterilizing the abdominal VNS electrode array and surgical protocol in rats. We also describe the technology required for confirmation of suprathreshold stimulation by recording evoked compound action potentials. Abdominal VNS has the potential to offer selective, effective treatment for a variety of conditions, including inflammatory diseases, and the application is expected to expand similarly to cervical VNS.

Long-term outcomes of cardioneuroablation with and without extra-cardiac vagal stimulation confirmation in severe cardioinhibitory neurocardiogenic syncope.

BACKGROUND: Cardioneuroablation (CNA) is a novel therapeutic approach for functional bradyarrhythmias, specifically neurocardiogenic syncope or atrial fibrillation, achieved through endocardial radiofrequency catheter ablation of vagal innervation, obviating the need for pacemaker implantation. Originating in the nineties, the first series of CNA procedures was published in 2005. Extra-cardiac vagal stimulation (ECVS) is employed as a direct method for stepwise denervation control during CNA. OBJECTIVE: This study aimed to compare the long-term follow-up outcomes of patients with severe cardioinhibitory syncope undergoing CNA with and without denervation confirmation via ECVS. METHOD: A cohort of 48 patients, predominantly female (56.3%), suffering from recurrent syncope (5.1 ± 2.5 episodes annually) that remained unresponsive to clinical and pharmacological interventions, underwent CNA, divided into two groups: ECVS and NoECVS, consisting of 34 and 14 cases, respectively. ECVS procedures were conducted with and without atrial pacing. RESULTS: Demographic characteristics, left atrial size, and ejection fraction displayed no statistically significant differences between the groups. Follow-up duration was comparable, with 29.1 ± 15 months for the ECVS group and 31.9 ± 20 months for the NoECVS group (p = .24). Notably, syncope recurrence was significantly lower in the ECVS group (two cases vs. four cases, Log Rank p = .04). Moreover, the Hazard ratio revealed a fivefold higher risk of syncope recurrence in the NoECVS group. CONCLUSION: This study demonstrates that concluding CNA with denervation confirmation via ECVS yields a higher success rate and a substantially reduced risk of syncope recurrence compared to procedures without ECVS confirmation.

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.

Quantitative assessment of transient autonomic modulation after single-shot pulmonary vein isolation with pulsed-field ablation.

INTRODUCTION: Pulmonary vein isolation (PVI) with thermal energy is characterized by concomitant ablation of the surrounding ganglionated plexi (GP). Pulsed-field ablation (PFA) selectively targets the myocardium and seems associated with only negligible effects on the autonomic nervous system (ANS). However, little is known about the dynamic effects of PFA on the GP immediately after PVI. This study sought to investigate the degree and acute vagal modulation induced by the FarapulseTM PFA system during PVI compared with single-shot thermal ablation. METHODS: A total of 76 patients underwent first-time PVI with either FarapulseTM PFA (PFA group, n = 40) or cryoballoon ablation (thermal ablation group, n = 36) for paroxysmal atrial fibrillation (AF). The effect on the ANS in the two groups was assessed before and after PVI with extracardiac vagal stimulation (ECVS). To capture any transient effects of PFA on the ANS, in a subgroup of PFA patients ECVS was repeated at three predefined timepoints: (1) before PVI (T0); (2) immediately after PVI (T1); and (3) 10 min after the last energy application (T2). RESULTS: Despite similar baseline values, the vagal response induced by ECVS after PVI almost disappeared in the thermal ablation group but persisted in the PFA group (thermal group: 840 [706-1090] ms, p < .001 compared to baseline; PFA group: 11 466 [8720-12 293] ms, p = .70 compared to baseline). Intraprocedural vagal reactions (defined as RR increase >50%, transitory asystole, or atrioventricular block) occurred more frequently with PFA than thermal ablation (70% vs. 28%, p = .001). Moreover, heart rate 24 h post-PVI increased more with thermal ablation than with PFA (16.5 ± 9.0 vs. 2.6 ± 6.1 beats/min, p < .001). In the subgroup of PFA patients undergoing repeated ANS modulation assessment (n = 11), ECVS demonstrated that PFA determined a significant acute suppression of the vagal response immediately after PVI (p < .001 compared to baseline), which recovered almost completely within 10 min. CONCLUSION: PVI with the FarapulseTM PFA system is associated with only transitory and short-lasting vagal effects on the ANS which recover almost completely within a few minutes after ablation. The impact of this phenomenon on AF outcome needs to be further investigated.

Report of a vagal paraganglioma at the cervicothoracic junction.

BACKGROUND: Vagus nerve paragangliomas are rare tumors, comprising 0.03% of head and neck neoplasms. These tumors are usually located cephalad to the hyoid bone, and there is only one previously reported case that arose from the lower third of the neck. METHODS: We describe the second reported case of a lower neck vagus nerve paraganglioma that was managed with a limited sternotomy for access and surgical removal. RESULTS: A 66-year-old male presented with a long-standing lesion of the cervicothoracic junction. CT, MRI, and Ga-68 DOTATATE PET/CT showed an avidly enhancing 5.2 × 4.2 × 11.5 cm mass extending from C6 to approximately T4 level. FNA confirmed the diagnosis. The patient underwent catheter angiography and embolization via direct puncture technique followed by excision of the mass via a combined transcervical and limited sternotomy approach. CONCLUSION: We describe an unusual case of vagal paraganglioma at the cervicothoracic junction with retrosternal extension requiring a sternotomy for surgical excision.

Application of Adhesive Skin Electrode for Intraoperative Neuromonitoring During Enucleation of a Cervical Vagal Schwannoma.

BACKGROUND: No reports on applying adhesive skin electrodes for intraoperative nerve monitoring (IONM) of the vagus nerve during schwannoma enucleation have been reported in the literature. METHODS: A 45-year-old patient was referred to our institution with a 2.2 cm mass in the left lateral neck, suspected to be a vagal nerve schwannoma. A pair of surface electrodes were attached to the lateral margin of the thyroid cartilage. After exposing the tumor, the authors selected the incision site avoiding the expected course of the vagus nerve fibers after mapping on the surface of the tumor. RESULTS: Postoperative vocal cord function was intact, without aspiration or dysphagia. CONCLUSIONS: The authors report the successful use of skin electrodes for IONM of the vagus nerve during cervical vagal schwannoma removal, suggesting the feasibility of applying these electrodes for IONM of neck surgeries other than those associated with the thyroid or parathyroid glands.

Resection of a schwannoma originating from vagus nerve in the right superior mediastinum.

BACKGROUND: Schwannoma is the most common mediastinal neurogenic tumor, while schwannoma originating from mediastinal vagus nerve is rare. CASE PRESENTATION: This article reported one case of schwannoma originating from vagus nerve in the right superior mediastinum. The mediastinal schwannoma was completely resected through a right-sided video-assisted thoracoscopic thoracotomy. Histologic examination clarified the diagnosis as schwannoma. CONCLUSION: Chest CT scan and MRI can be used to determine the location of mediastinal schwannoma and its relationship with adjacent tissue. Histologic examination showing distinctive feature of Antoni A areas and Antoni B areas can help clarify the diagnosis. Complete surgical resection is the first-line treatment option for mediastinal schwannomas.

Pulsed Field Ablation to Treat Atrial Fibrillation: Autonomic Nervous System Effects.

BACKGROUND: During atrial fibrillation ablations using thermal energy, the treatment effect is attributed to not just pulmonary vein isolation (PVI), but also to modulation of the autonomic nervous system by ablation of cardiac ganglionated plexi (GP). OBJECTIVES: This study sought to assess the impact of pulsed field ablation (PFA) on the GP in patients undergoing PVI. METHODS: In the retrospective phase, heart rate was assessed pre- versus post-PVI using PFA, cryoballoon ablation, or radiofrequency ablation. In the prospective phase, a pentaspline PFA catheter was used in a protocol: 1) pre-PFA, high-frequency stimulation (HFS) identified GP sites by vagal effects; 2) PVI was performed assessing for repetitive vagal effects over each set of PF applications; 3) mapping defined PVI extent to identify those GP in the ablation zone; and 4) repeat HFS at GP sites to assess for persistence of vagal effects. RESULTS: Between baseline and 3 months, heart rates in the retrospective radiofrequency ablation (n = 40), cryoballoon (n = 40), and PFA (n = 40) cohorts increased by 8.9 ± 11.4, 11.1 ± 9.4, and -0.1 ± 9.2 beats/min, respectively (P= 0.01 PFA vs radiofrequency ablation; P= 0.01 PFA vs cryoballoon ablation). In the prospective phase, pre-PFA HFS in 20 additional patients identified 65 GP sites. During PFA, vagal effects were noted in 45% of first PF applications, persisting through all applications in 83%. HFS post-PFA reproduced vagal effects in 29 of 38 sites (76%) in low-voltage tissue. CONCLUSIONS: PFA has minimal effect on GP. Unlike with thermal ablation, the mechanism by which PFA treats atrial fibrillation is mediated solely by durable PVI.

A Gastrectomy for early-stage gastric cancer patients with or without preserving celiac branches of vagus nerves: A meta-analysis.

BACKGROUND: Vagus nerve-preserving gastrectomy is increasingly popular in treating gastric cancer in the early stage, however the long and short-term outcomes after gastrectomy while preserving the celiac branch of the vagus nerve are not well defined. We aimed to summarize and compare perioperative and longer-term outcomes after celiac branch vagus nerve-preserving gastrectomy (CBP, preserving both the celiac and hepatic branches of the vagus nerve), compared to those without CBP (non-CBP, only the hepatic branch of the vagus nerve is preserved). METHODS: We searched the Embase, PubMed, Cochrane Library and Web of Science databases for papers published before October 2021. The primary results were evaluated by short-term and long-term postoperative complications, whereas the secondary outcomes included surgery-related parameters, recovery-related parameters and overall survival. Random-effects or fixed-effects model were used to estimate odds ratio, and weighted mean difference for the outcomes. The underlying publication bias was identified via funnel charts, Begg's test and Egger's test. Sensitivity analysis was conducted by removing the research one by one. RESULTS: A total of 9 studies consisting of 8 retrospective studies and one randomized control trial were included. The analysis included 1,109 patients, with 568 (51.2%) of patients receiving CBP and 541 (48.8%) patients who received non-CBP. The CBP group had a shorter time in terms of first flatus (weighted mean difference = -0.436, 95% confidence interval: -0.603 to -0.269; P < 0.001) and hospital stay (weighted mean difference = -0.456, 95% confidence interval: -0.874 to -0.037, P = 0.033) than the non-CBP group, but the time to the start of oral intake was comparable between the groups. Regarding short-term complications and surgery-related parameters, between CBP and non-CBP, no evident differences were observed in pancreatic complications, anastomotic leakage, postoperative bleeding, operation time, blood loss or lymph nodes examined. In terms of long-term complications, the incidence of gallstones in CBP was lower than that in non-CBP (odds ratio = 0.582, 95% confidence interval: 0.356-0.953, P = 0.031), and the incidence of bile reflux in CBP was lower than that in non-CBP (odds ratio = 0.473, 95% confidence interval: 0.280-0.800, P = 0.005). However, the prevalence rates of diarrhea, early dumping syndrome, esophageal reflux, and delayed gastric emptying were comparable between CBP and non-CBP. CONCLUSION: The present research showed that gastric cancer patients in the early stage under CBP were superior to those without CBP in terms of incidence of gallstones, bile reflux, time of first flatus and hospital stay. Furthermore, it is imperative to conduct randomized control studies with larger sample sizes to determine the oncological survival outcomes when preserving the celiac branch.

Vagus nerve-guided (modified Bai-Jiang-style) robotic-assisted laparoscopic splenectomy and azygoportal disconnection.

BACKGROUND: How to precisely protect and preserve anterior and posterior vagal trunks and all their branches during the procedure of splenectomy and azygoportal disconnection is studied rarely. We firstly developed a vagus nerve-guided robotic-assisted laparoscopic splenectomy and azygoportal disconnection (VGRSD). The aim of this study was to evaluate whether VGRSD is feasible and safe and to determine whether VGRSD can effectively eliminate postoperative digestive system complications by protecting vagal nerve precisely. METHOD: In this prospective clinical study, 10 cirrhotic patients with oesophagogastric variceal bleeding and hypersplenism who underwent VGRSD between January 2022 and March 2022 were gathered, and compared with a retrospective cohort who received a part of the vagus nerve-preserving robotic-assisted laparoscopic splenectomy and azygoportal disconnection (VPRSD). They were all followed up for 6 months. RESULTS: In VGRSD group, the operation time was 173.5 ± 16.2 min, blood loss was 68.0 ± 39.1 ml, VAS pain score on the first day was 1.9 ± 0.7, and the postoperative hospital stay was 7.7 ± 0.7 days. There was no incisional complications, pneumonia, gastric fistula, pancreatic fistula, and abdominal infection. No patients suffered from diarrhoea, delayed gastric emptying, and epigastric fullness. Compared with VPRSD, operation time was significantly longer for VGRSD (p < 0.05). However, VGRSD was significantly associated with less diarrhoea and shorter postoperative hospital stay (all p < 0.05). CONCLUSION: VGRSD procedure is not only technically feasible and safe, it also effectively eliminate postoperative digestive system complications. TRIAL REGISTRATION: We registered our research at https://www. CLINICALTRIALS: gov/. The name of research registered is 'Vagus Nerve-guided Robotic-assisted Splenectomy and Azygoportal Disconnection'. The trial registration identifier at clinicaltrials.gov is NCT05300516.

[A case report of giant vagal schwannoma in the right neck and literature review].

Vagal nerve-derived schwannomas are rare, especially those with huge tumors. This paper reports a case of giant tumor in the right neck. The patient was misdiagnosed as pleomorphic adenoma before operation, and was diagnosed as schwannoma during operation. The clinical manifestations, diagnosis, differential diagnosis, treatment and prognosis are discussed in this paper based on the history and related literature.

Cervical vagal nerve schwannoma induced arrhythmia: a rare case report and literature review.

BACKGROUND: Schwannomas are benign tumors deriving from the sheath of cranial and peripheral nerves. The vagus nerve is comprised of a complex neuro-endocrine-immune network that maintains homeostasis, most tracts of it play a role in parasympathetic activity. We present an example of a rare cervical vagal schwannoma case accompanied by arrhythmia. CASE PRESENTATION: A 35-year-old female patient with a left cervical vagus schwannoma and ventricular arrhythmia underwent schwannoma resection in the operating room. The patient's suppressed heart rate increased after tumor removal, and the cardiac rhythm returned to normal postoperatively. Pathological examination demonstrated the diagnosis of schwannoma. CONCLUSIONS: This case explains the link between the vagus nerve and the cardiovascular system, proving that a damaged cervical vagus nerve can inhibit the heart rate and lead to arrhythmias, and eventually requiring surgical intervention.

Application of Vagus Nerve Branch Preservation in Thoracoscopic Surgery for Early-Stage Lung Cancer.

Background: In this study, we introduced a novel surgical strategy to protect vagal nerve branches during radical thoracoscopic surgery in right lung cancer and explored the effects of vagal nerve branch preservation. Methods: We retrospectively studied 53 patients with right-sided lung cancer with clinically staged T1N0M0 between 2019 and 2020. All 53 patients were treated with total thoracoscopic lobectomy and mediastinal lymph node dissection in the same number of lymph node stations. Of these, 22 patients adopted a vagus nerve branch protection strategy during lymph node dissection. Another 31 patients were treated with traditional lymph node dissection as the control group. Results: The characteristics of the patients were similar between the two groups. The operation time and intraoperative bleeding in the protection group were longer than those in the control group. However, the protection group had a lower average postoperative pain score and average postoperative hospital stay. The above difference was not statistically significant. Three cases of arrhythmia occurred in the protection group, including 1 case of tachycardia and 2 cases of atrial fibrillation. In the control group, 13 cases of arrhythmia occurred after the operation, including 8 cases of tachycardia and 5 cases of atrial fibrillation. We also tracked changes in the patients' heart rates throughout the treatment process (excluding patients with arrhythmias). An increased heart rate was observed postoperatively in both groups, but the increase of heart rate of the protection group was smaller than that of the control group; however, the difference was not statistically significant. Conclusions: A vagus nerve branch preservation-based approach to radical surgery is a safe and feasible strategy for right lung cancer treatment, which could significantly reduce the risk of postoperative arrhythmia in patients and may also have a potential role in reducing the length of hospital stay and maintaining heart rate stability in the postoperative period.

Rise in Postprandial GLP-1 Levels After Roux-en-Y Gastric Bypass: Involvement of the Vagus Nerve-Spleen Anti-inflammatory Axis in Type 2 Diabetic Rats.

PURPOSE: The mechanism underlying postprandial glucagon-like peptide-1 (GLP-1) changes after metabolic surgery remains mostly unclarified. This investigation aimed to address whether the vagus nerve-spleen anti-inflammatory axis is involved in the rise in postprandial GLP-1 levels in type 2 diabetes mellitus (T2DM) rats following metabolic surgery. MATERIALS AND METHODS: T2DM rat model was established with a high-fat diet and a low dose of streptozotocin and subjected to Roux-en-Y gastric bypass (RYGB) and splenic denervation. A mixed-meal tolerance test for postprandial GLP-1 response was performed. TNF-α in the plasma, spleen, and ileum was measured by ELISA, and alpha 7 nicotinic acetylcholine receptor (α7nAChR) expression in the spleen was analyzed by Western blot. RESULTS: Postprandial GLP-1 improvement by RYGB was accompanied by the reduction of TNF-α levels in spleen and ileum and up-regulation of splenic α7nAChR in T2DM rats. Splenic denervation abrogates a rise in postprandial GLP-1 levels in response to the mixed-meal challenge, along with higher TNF-α levels in spleen and ileum and down-regulation of splenicα7nAChR, compared with denervated sham rats. CONCLUSION: Our results reveal that the vagus nerve-spleen anti-inflammatory axis mediates the rise of postprandial GLP-1 response after RYGB through lowering TNF-α contents in the intestinal tissue in T2DM rats.