Postoperative Impedance–pH Testing is Unreliable After Nissen Fundoplication With or Without Giant Hiatal Hernia Repair
Combined 24-h multichannel intralumenal impedance–pH monitoring (MII-pH) is gaining popularity as a diagnostic tool for gastroesophageal reflux. Since the surgical reduction of hiatal hernias and creation of a fundoplication anatomically restores the gastroesophageal reflux barrier, one would assume that it effectively stops all reflux regardless of composition. Our aim is to evaluate the results of routine MII-pH testing in successful Nissen fundoplication patients. Sixty-two patients with normal acid exposure, confirmed by 24-h pH testing, after Nissen fundoplication were evaluated with symptomatic questionnaire, esophageal manometry and MII-pH testing more than 6 months after surgery. Patients were grouped into normal and abnormal based on postoperative impedance results. Patients with Nissen alone were separately compared to patients with Nissen + giant hiatal hernia (GHH). Twenty-nine (47%) patients exhibited abnormal impedance after successful Nissen fundoplication. Abnormal impedance was associated with GHH repair, lower bolus pressures, and lower distal esophageal contraction amplitudes. Postoperative testing with the standard MII-pH catheters using published normative values seems to be clinically irrelevant. Clinicians should analyze the results of routine MII-pH testing in the setting of a fundoplication critically as the current technology is associated with a high false positive rate.