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Impedance-pH monitoring on medications does not reliably confirm the presence of gastroesophageal reflux disease in patients referred for antireflux surgery

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The gold standard for the objective diagnosis of gastroesophageal reflux disease (GERD) is ambulatory-pH monitoring off medications. Increasingly, impedance-pH (MII-pH) monitoring on medications is being used to evaluate refractory symptoms. The aim of this study was to determine whether an MII-pH test on medications can reliably detect the presence of GERD.


Patients referred for persistent reflux symptoms despite pH confirmed adequate acid suppression (DeMeester score ≤14.7) were reviewed retrospectively. All patients who originally had MII-pH testing on medications were re-evaluated with an off medication Bravo-pH study. Acid exposure results (defined by off medication Bravo) were compared to the original on medication MII-pH.


There were 49 patients who met study criteria (median age 51). Patients had normal acid exposure during their MII-pH test on medications (average DMS 4.35). Impedance was abnormal (normal ≤47) in 25 of the 49 patients (51%). On subsequent Bravo-pH off medications, 37 patients (75.7%) showed increased esophageal acid exposure (average DMS 36.4). Bravo-pH testing was abnormal in 84% of patients with abnormal MII testing and in 67% with normal MII testing. The sensitivity and specificity of an abnormal MII-pH on medications for increased esophageal acid exposure off medications was 56.8 and 66.7%, respectively. The positive predictive value of confirming GERD from an abnormal MII-pH on medications is 84%, while the negative predictive value is 33.3%. A receiver operating characteristic (ROC) curve was generated and the area under the curve was 0.71, indicating that MII-pH on medications is a fair test (0.7–0.8) in diagnosing pathologic GERD.


Compared to the gold standard, MII-pH on medications does not reliably confirm the presence of GERD. Excellent outcomes with antireflux surgery are dependent on the presence of GERD; thus, patients should not be offered antireflux surgery until GERD is confirmed with pH testing off medications.

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  1. Dent J, El-Serag HB, Wallander MA et al (2005) Epidemiology of gastrooesophageal reflux disease: a systematic review. Gut 54:710–717

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  2. Locke GR, Talley NJ, Fett SL et al (1997) Prevalence and clinical spectrum of gastroesophageal reflux: a population-based study in Olmsted County, Minnesota. Gastroenterology 112:1448–1456

    Article  PubMed  Google Scholar 

  3. Anderson WD 3rd, Strayer SM, Mull SR (2015) Common questions about the management of gastroesophageal reflux disease. Am Fam Physician 91(10):692–697

    PubMed  Google Scholar 

  4. Kahrilas PJ, Shaheen NJ, Vaezi MF (2008) American Gastroenterological Association Institute technical review on the management of gastroesophageal reflux disease. Gastroenterology 135:1383–1413

    Article  PubMed  Google Scholar 

  5. Kenneth R, DeVault DOC (2005) Updated guidelines for the diagnosis and treatment of gastroesophageal reflux disease. Am J Gastroenterol 100:190–200

    Article  Google Scholar 

  6. Tutuian R, Castell D (2006) Review article: complete gastro-oesophageal reflux monitoring—combined pH and impedance. Aliment Pharmacol Ther 24(Suppl 2):27–37

    Article  PubMed  Google Scholar 

  7. Agrawal A, Castell D (2008) Clinical importance of impedance measurements. J Clin Gastroenterol 42:579–583

    Article  PubMed  Google Scholar 

  8. Park W, Vaezi M (2005) Esophageal impedance recording: clinical utility and limitations. Curr Gastroenterol Rep 7:182–189

    Article  PubMed  Google Scholar 

  9. Sifrim D, Blondeau K (2006) Technology insight: the role of impedancetesting for esophageal disorders. Nat Clin Pract Gastroenterol Hepatol 3:210–219

    Article  PubMed  Google Scholar 

  10. Peters JH, DeMeester TR, Crookes P, Oberg S, de Vos Shoop M, Hagen JA, Bremner CG (1998) The treatment of gastroesophageal reflux disease with laparoscopic Nissen fundoplication: prospective evaluation of 100 patients with “typical” symptoms. Ann Surg 228(1):40–50

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  11. Tutuian R, Mainie I, Agrawal A et al (2006) Normal values for ambulatory 24-h combined impedance-pH monitoring on acid suppressive therapy. Gastroenterology 130(Suppl 2):A171

    Google Scholar 

  12. Pandolfino J, Richter J, Ours T et al (2003) Ambulatory esophageal pH monitoring using a wireless system. Am J Gastroenterol 98:740–749

    Article  PubMed  Google Scholar 

  13. Campos GM, Peters JH, DeMeester TR, Öberg S, Crookes PF, Tan S, DeMeester SR, Hagen JA, Bremner CG (1999) Multivariate analysis of factors predicting outcome after laparoscopic Nissen fundoplication. J Gastrointest Surg 3(3):292–300

    Article  CAS  PubMed  Google Scholar 

  14. Hemmink GJ, Bredenoord AJ, Weusten BL, Monkelbaan JF, Timmer R, Smout AJ (2008) Esophageal pH-impedance monitoring in patients with therapy-resistant reflux symptoms:‘on’or ‘off’proton pump inhibitor? Am J Gastroenterol 103(10):2446–2453

    Article  PubMed  Google Scholar 

  15. Ayazi S, Lipham JC, Portale G, Peyre CG, Streets CG, Leers JM, DeMeester SR, Banki F, Chan LS, Hagen JA, DeMeester TR (2009) Bravo catheter-free pH monitoring: normal values, concordance, optimal diagnostic thresholds, and accuracy. Clin Gastroenterol Hepatol 7(1):60–67

    Article  PubMed  Google Scholar 

  16. Zentilin P, Iiritano E, Dulbecco P, Bilardi C, Savarino E, De Conca S, Parodi A, Reglioni S, Vigneri S, Savarino V (2006) Normal values of 24-h ambulatory intraluminal impedance combined with pH-metry in subjects eating a Mediterranean diet. Digest Liver Dis 38(4):226–232

    Article  CAS  Google Scholar 

  17. Doulami G, Triantafyllou S, Natoudi M, Albanopoulos K, Menenakos E, Filis K, Zografos G, Theodorou D (2016) Normal values of 24H multichannel intraluminal impedance pH-metry in a Greek obese population based on montreal definition of Gerd. Obes Surg 26(1):126–131

    Article  PubMed  Google Scholar 

  18. Moawad FJ, Betteridge JD, Boger JA, Cheng FK, Belle LS, Chen YJ, Maydonovitch CL, Wong RK (2013) Reflux episodes detected by impedance in patients on and off esomeprazole: a randomised double-blinded placebo-controlled crossover study. Aliment Pharmacol Ther 37(10):1011–1018

    Article  CAS  PubMed  Google Scholar 

  19. Zerbib F, des Varannes S, Roman S et al (2005) Normal values and day-to-day variability of 24-h ambulatory oesophageal impedance-pH monitoring in a Belgian; French cohort of healthy subjects. Aliment Pharmacol Ther 22:1011–1021

    Article  CAS  PubMed  Google Scholar 

  20. Xiao YL, Lin JK, Cheung TK, Wong NY, Yang L, Hung IF, Wong BC, Chen MH (2009) Normal values of 24-hour combined esophageal multichannel intraluminal impedance and pH monitoring in the Chinese population. Digestion 79(2):109–114

    Article  PubMed  Google Scholar 

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The authors would like to acknowledge Angie Gill, RN, and Lisa Leeth for their help coordinating the clinical aspects of this study.

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Correspondence to Steven R. DeMeester.

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Dr. Reavis is a consultant for Boston Scientific, Endogastric Solutions, and Stryker, and receives teaching or advisory honoraria from Ethicon, Mederi, Gore, and Apollo. Dr. Swanstrom is on the scientific advisory boards of Olympus and Boston Scientific. Dr. DeMeester is a consultant for Bard, Gore, Endogastric solutions, C2 Therapeutics, Novadaq, Mauna Kea, and CDx Diagnostics. Drs. Ward, Dunst, Teitelbaum, and Halpin have no disclosures or conflicts of interest to report. These disclosures are not relavent to the current study.

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Ward, M.A., Dunst, C.M., Teitelbaum, E.N. et al. Impedance-pH monitoring on medications does not reliably confirm the presence of gastroesophageal reflux disease in patients referred for antireflux surgery. Surg Endosc 32, 889–894 (2018).

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