Intraoperative Vagus Nerve Stimulation Accelerates Postoperative Recovery in Rats

Postoperative ileus (POI) is a heavy burden for healthcare industries and reduces the postoperative quality of life. The aim of this study was to investigate the effects and mechanisms of the intraoperative vagus nerve stimulation (iVNS) on gastrointestinal motility in a rodent model of POI.

For control group (control, n = 8), electrodes were placed on the chest wall for recording the electrocardiogram and on the stomach and small intestine for measuring gastric slow waves (GSWs) and small intestinal slow waves (SSWs). For sham group (sham, n = 8) and iVNS group (VNS, n = 8), after the same surgery as the control, intestinal manipulation (IM) was performed to induce POI. iVNS was performed during the surgery for the iVNS group. Small intestinal transit (SIT), gastric emptying (GE), postoperative pain, and plasma TNF-α were evaluated after operation.

IM delayed GE that was normalized by iVNS (P < 0.05). iVNS reduced plasma TNF-α increased by IM (P = 0.04). iVNS prevents the injury of ileum mucosa induced by IM (P < 0.05). iVNS reduced the postoperative pain (P < 0.05). iVNS prevented the IM-induced decrease in vagal activity (sham 0-30 min vs. 150-180 min, P = 0.03, VNS 0-30 min vs. 150-180 min, P = 0.58) and increase in sympathovagal balance (sham 0-30 min vs. 150-180 min, P = 0.04, VNS 0-30 min vs. 150-180 min, P = 0.72).

iVNS accelerates postoperative recovery by improving GE, reducing postoperative pain, and preventing the injury of ileum mucosa mediated via the autonomic mechanisms.