Endoscopic ultrasound for the evaluation of Nissen fundoplication integrity: A blinded comparison with conventional testing

Background: For patients whose symptoms develop after Nissen fundoplication, the precise mechanism of anatomic failure can be difficult to determine. The authors have previously reported the endosonographic hallmarks defining an intact Nissen fundoplication in swine and the known causes of failure. The current clinical trial tested the hypothesis that a defined set of endosonographic criteria can be applied to determine fundoplication integrity in humans. Methods: The study enrolled seven symptomatic and nine asymptomatic subjects at a mean of 6 years (range, 1-30 years) after Nissen fundoplication. A validated gastroesophageal reflux disease (GERD)-specific questionnaire and medication history were completed. Before endoscopic ultrasound (EUS), all the patients underwent complete conventional testing (upper endoscopy, esophagram, manometry, 24-h pH). A diagnosis was rendered on the basis of combined test results. Then EUS was performed by an observer blinded to symptoms, medication use, and conventional testing diagnoses. Because EUS and esophagogastroduodenoscopy (EGD) are uniformly performed in combination, the EUS diagnosis was rendered on the basis of previously established criteria combined with the EGD interpretation. The diagnoses then were compared to examine the contribution of EUS in this setting. Results: The technique and defined criteria were easily applied to all subjects. All symptomatic patients had heartburn and were taking proton pump inhibitors (PPI). No asymptomatic patients were taking PPI. All diagnoses established with combined conventional testing were detected on EUS with upper endoscopy. Additionally, EUS resolved the etiology of a low lower esophageal sphincter pressure in two symptomatic patients and detected the additional diagnoses of slippage in two subjects. Among asymptomatic subjects, EUS identified additional diagnoses in two subjects considered to be normal by conventional testing methods. Conclusion: According to the findings, EUS is a feasible method for evaluating post-Nissen fundoplication hiatal anatomic relationships. The combination of EUS and EGD allows the mechanism of failure to be detected in patients presenting with postoperative symptoms after Nissen fundoplication.