Fig. 2

Schematic diagram illustrating the effect of vagotomy on PONV. Four neural pathways potentially send stimulating inputs to the nucleus of the solitary tract (NTS) in the hindbrain: 1) gut vagal afferent fibers (yellow line) from the gastrointestinal tract; 2) motion-related vestibular input from the vestibular nuclei (Vnu); 3) area postrema (AP) and 4) descending pathways from the forebrain. NTS then produces the emetic reflex by activating its output pathways within local brainstem areas and causes nausea by projecting to the mid- and forebrain. However, which one of these four neuronal pathways as the primary mediator of PONV is still unknown. In this cohort study, occurrence of PONV is about 30% after non-vagotomy surgery (hepatectomy, pulmonary lobectomy and colorectomy), while PONV is reduced to approximately10% after vagotomy surgery (esophagectomy and gastrectomy) and selective vagotomy, suggesting that vagus nerve dependent gut-brain signaling mainly contributes to PONV