title: Postoperative impedance-pH testing is unreliable after Nissen fundoplication with or without giant hiatal hernia repair.
abstract: BACKGROUND
  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.
  
  
  METHODS
  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).
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  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.
authors: Division of Gastrointestinal and Minimally Invasive Surgery, The Oregon Clinic, Portland, OR 97210, USA.
authors: Brittany N
authors: BN
authors: Arnold
authors: Christy M
authors: CM
authors: Dunst
authors: Angi B
authors: AB
authors: Gill
authors: Trudie A
authors: TA
authors: Goers
authors: Lee L
authors: LL
authors: Swanström
mesh_terms: D000328:Adult; D000368:Aged; D017097:Electric Impedance; D050782:Esophageal pH Monitoring; D004947:Esophagus / Q000503:physiopathology*; D005260:Female; D018662:Fundoplication; D005764:Gastroesophageal Reflux / Q000503:physiopathology / Q000601:surgery*; D006551:Hernia, Hiatal / Q000601:surgery*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008365:Manometry; D008875:Middle Aged; D009119:Muscle Contraction / Q000502:physiology; D011184:Postoperative Period; D011446:Prospective Studies; D011795:Surveys and Questionnaires