From the Guidelines
The anterior and posterior branches of the vagus nerve play crucial roles in innervating abdominal organs, with the anterior branch primarily supplying the anterior and lesser curvature of the stomach, liver, and portions of the duodenum, and the posterior branch innervating the posterior stomach wall, greater curvature, and continuing to supply the intestines, including the small intestine and proximal two-thirds of the large intestine, as noted in studies such as 1 and 1. The vagus nerve, also known as cranial nerve X, has a complex anatomy that is vital for various bodily functions, including digestion and respiration.
- The anterior branch of the vagus nerve contains predominantly parasympathetic fibers that stimulate gastric acid secretion.
- The posterior branch carries fibers important for gastric motility and intestinal function, as discussed in 1. Understanding the branching pattern of the vagus nerve is essential for surgeons operating in the upper abdomen and for comprehending the pathophysiology of conditions affecting vagal function, such as gastroparesis or certain types of abdominal pain syndromes, as highlighted in 1 and 1. In clinical practice, preserving the hepatic branch of the anterior vagus and/or the celiac branch of the posterior vagus is crucial, as reported in 1. The most recent and highest quality study, 1, emphasizes the importance of imaging protocols that visualize the full extent of the vagus nerve from the skull base to the mid chest, particularly in cases of vocal cord paralysis. Key points to consider include:
- The vagus nerve's long course makes it vulnerable to various pathologies, as noted in 1 and 1.
- Lesions anywhere along the course of the vagus nerve may potentially cause vocal cord paralysis, as discussed in 1 and 1.
- Imaging protocols, such as MRI and CT, play a crucial role in evaluating the vagus nerve and its branches, as highlighted in 1 and 1.
From the Research
Anterior and Posterior Branch of the Vagus Nerve
The vagus nerve is a complex structure with various branches, including the anterior and posterior branches. However, the provided studies do not specifically discuss the anterior and posterior branches of the vagus nerve.
Vagus Nerve Structure and Function
- The vagus nerve is an indispensable body-brain connection that controls vital aspects of autonomic physiology, such as breathing, heart rate, and gut motility 2.
- It is dominated by sensory axons originating in the heart, lungs, and airways, and the gastrointestinal tract 3.
- The vagus nerve has a tremendous diversity of sensory neuron types that innervate different internal organs 2.
Vagus Nerve Stimulation and Clinical Applications
- Vagal nerve stimulation (VNS) therapy is a surgical treatment that involves the implantation of a device to electrically stimulate the vagus nerve 4.
- VNS is indicated as an adjunctive treatment of epilepsy that is refractory to antiepileptic medications and for treatment-resistant depression 4.
- VNS has also shown efficacy in the treatment of certain gastrointestinal disorders 3.
Clinical Implications and Complications
- VNS can affect vocal fold function, leading to voice complaints of hoarseness 5, 4.
- Common complications of VNS therapy include hoarseness, throat pain/dysphagia, coughing, and shortness of breath 4.
- Vagus nerve schwannomas are rare, benign masses that can develop anywhere along the vagus nerve, and may present with symptoms such as dysphagia, slurred speech, and cervical masses 6.