Up to 80% of non-cancer patients on chronic opioids develop opioid-induced constipation (OIC), which worsens over time. Using a pig model of OIC induced by chronic loperamide, we evaluated whether cervical vagus nerve stimulation (CBVNS) could alleviate constipation.
We collaborate with Dr. Million Mulugeta’s team from UCLA medical school and created a OIC porcine model. These Yucatan minipigs were implanted with CBVN cuff electrodes and cecal cannulas, then administered daily loperamide. Colon motility was assessed via manometry. Acute CBVNS effects were tested in naïve-anesthetized pigs, while repeated CBVNS (R-CBVNS) was applied in OIC pigs. Manometry data from multiple colon segments were analyzed using motility index, frequency band power, and burst contraction features.
Acute CBVNS induced pan-colonic contractions. R-CBVNS improved motility in OIC pigs by enhancing proximal colon contraction frequency and modulating contraction rate, duration, and possibly secretory function, as indicated by increased stool water content.
Published Paper: https://doi.org/10.1111/nmo.13925 https://doi.org/10.1152/physiol.2024.39.S1.1242
