The protective effect of cutaneous vagus nerve stimulation from necrotizing enterocolitis (NEC) in neonatal rats

Necrotizing enterocolitis (NEC) is a major source of morbidity and mortality among premature infants. Vagus nerve stimulation (VNS) has proven anti-inflammatory effects. Animal studies indicate that vagus nerve activity may dampen NEC inflammation.

We used an animal model that induces NEC in rat pups. Newborn pups were divided into six treatment groups: Pups receiving NEC induction with Actual VNS, Sham VNS, and No VNS; and pups not receiving NEC induction with Actual VNS, Sham VNS, and No VNS (total n = 112). After death, gastrointestinal (GI) samples were graded 0-4 using the NEC Histologic Injury Scoring System. NEC incidence was defined as grades 2-4. Length of survival and premature mortality were also quantified.

Among NEC induction pups, the differences between NEC scores and NEC incidence were not statistically significant. However, those pups who received Actual VNS or Sham VNS had a longer average survival (p = 0.014) and lower chance of premature mortality (p = 0.004). These effects were stronger when Any VNS pups (Actual and Sham VNS pups combined) were compared to No VNS pups (p = 0.0009 and 0.003, respectively).

Our results suggest a possible protective effect of both electrical and tactile cutaneous VNS against mortality among NEC patients.

Vagus nerve stimulation (VNS) has proven anti-inflammatory properties in human adults, and represents a possible new treatment for necrotizing enterocolitis (NEC). Using an animal model for NEC, we found that cutaneous VNS is protective against the development and severity of NEC. These protective effects held true for both electrical and tactile VNS. Our results suggest a potentially promising new treatment for NEC in the neonatal population.