Exploration of Transcutaneous Vagus Nerve Stimulation As a Treatment Option for Adjuvant Cancer and Heart Failure Therapy

Vagus nerve stimulation (VNS) has gained prominence in the treatment of various clinical disorders such as migraine, depression, and tinnitus. Based on increased scientific knowledge of the VNS and insights into the vagus nerve (VN) function and anatomy/conduction, robust treatment approaches have been developed. There are both noninvasive and invasive VNS (iVNS) techniques. Currently, only iVNS techniques are approved by the US Food and Drug Administration (FDA). In contrast, transcutaneous VNS (tVNS) is a new treatment option that is receiving increasing attention. The tVNS application uses the cutaneous distribution of afferent VN fibers in the auricle, the auricular branch of the VN (ABVN), or in the neck, the cervical branch of the VN (CBVN). However, the tVNS technique has not yet been sufficiently researched in its application and mode of action to be used clinically on a large scale. Moreover, the stimulation parameters of the VN vary widely in different studies. Despite the growing number of research papers on this topic, more coherence in neurostimulation research and neuroanatomical basis is needed. The aim of this review is to highlight new clinical treatment options based on existing clinically applied treatment options. In this article, current clinical applications of tVNS are analyzed and important stimulation parameters are highlighted. Based on this data, useful new tVNS therapies are recommended. The focus will be placed on the study of inflammatory processes associated with cancer and on applications to cardiovascular events such as heart failure.