Impact of vagus nerve integrity testing on surgical management in patients with previous operations with potential risk of vagal injury

Background Thoracic and foregut operations can cause vagal nerve injury resulting in delayed gastric emptying or gastroparesis. However, the cause of gastroparesis in these patients is not always from a vagal injury. We hypothesize that vagal nerve integrity (VNI) testing may better define who has vagal nerve dysfunction. This information may change subsequent operations. The aim of this study was to evaluate the impact of VNI testing in patients with prior thoracic or gastric surgery. Methods From January 2014 to December 2017, patients who had previous operations with the potential risk of vagal injury and had VNI testing were reviewed. Excluded patients were those with no plan for a second operation or the second operation was only for gastroparesis. The main outcome was the percentage of operations altered due to the results of VNI testing. Results Twelve patients (eight females) were included. Ages ranged from 37 to 77 years. VNI results were compatible with vagal injury in eight patients (67%). VNI test results altered subsequent operative plans in 41.7% (5/12). Pyloroplasty was done in addition to fundoplication in two patients. Plans for hiatal hernia repair with or without redo-fundoplication in three patients were changed by an additional pyloroplasty in one patient and partial gastrectomy with Roux-en-Y reconstruction in two patients. All patients who had secondary surgery had resolution of symptoms and improvement in objective testing. Conclusion The addition of VNI testing in patients with a previous potential risk of vagal nerve injury may help the surgeon select the appropriate secondary operation.