Pain is one of the main causes for people to seek medical help. One approach for relieving pain is auricular vagus nerve stimulation (aVNS), which uses a stimulation unit and surface electrodes on the ear to transmit weak electrical current pulses along the vagus nerve to the brain in order to influence pain.

This systematic review evaluates the efficacy and safety of aVNS for pain relief in patients with acute postoperative and chronic pain. In total, four RCTs on acute postoperative pain and six RCTs on chronic pain were included. The comparison groups received standard therapy or sham treatment. Regarding postoperative pain, aVNS showed improvement in rebound pain after anterior cruciate ligament (ACL) reconstruction. For chronic pain, improvement was observed in gastrointestinal pain, migraine without aura, and myofascial pain syndrome. Adverse (device-related) events were rare.

The overall evidence of effectiveness and safety was rated as very low to high. The use of aVNS for postoperative and chronic pain was found to be an effective and safe adjunctive therapy in selected patients and indications.