The Role of Distal Mean Nocturnal Baseline Impedance in Differentiating GERD Phenotypes.

BACKGROUND AND AIMS: Gastroesophageal reflux disease (GERD) is one of the most frequent digestive pathologies. The current diagnosis of GERD either by trial of proton pump inhibitors (PPIs), endoscopy or by multichannel impedance pH study (MII/pH) has limitations. Our study aims to show if mean nocturnal baseline impedance (MNBI) can differentiate between the GERD phenotypes. METHODS: We recruited 62 patients who underwent upper digestive endoscopy and MII/pH, with some patients undergoing esophageal manometry to exclude motility disorders. Patients were separated into 4 GERD phenotypes: erosive reflux disease (ERD), non-erosive reflux disease (NERD), reflux hypersensitivity (RH) and functional heartburn (FH). Proximal MNBI was calculated as the mean value of the proximal 2 channels (Z1 and Z2), and distal MNBI was calculated as the mean value of the distal 4 channels (Z3, Z4, Z5, Z6). RESULTS: Distal MNBI can help distinguish the abnormal acid exposure time (AET) phenotypes (ERD, NERD) from normal AET phenotypes (RH, FH) with a decent performance (AUROC 0.857). Distal MNBI has good accuracy in separating ERD from other phenotypes (AUROC 0.872). Furthermore, distal MNBI can differentiate FH from ERD, NERD, RH with good accuracy (AUROC 0.879), and on top of that is able to separate FH from RH (AUROC 0.817). CONCLUSIONS: Our study showed that distal MNBI is a good method of differentiating GERD phenotypes and should be taken into consideration in future studies to assess its validity in helping physicians make the correct diagnosis.

The role of spleen stiffness using ARFI in predicting esophageal varices in patients with Hepatitis B and C virus-related cirrhosis.

INTRODUCTION: Current guidelines recommend that all patients with cirrhosis undergo upper gastrointestinal endoscopy (UGE) screening for esophageal varices (EV). Unfortunately, UGE has a lot of disadvantages, consequently various non-invasive methods of diagnosing EV have been proposed. We evaluated if spleen stiffness (SS) measured by Acoustic Radiation Force Impulse (ARFI) is a viable technique in diagnosing EV. METHODS: We recruited 178 patients with cirrhosis caused by Hepatitis B and C who underwent biochemical tests, abdominal ultrasound, UGE, LS and SS measurements using ARFI elastography. Based on the endoscopic results the patients were divided in 3 groups: without EV, with small EV (<5 mm) and with large EV (>5 mm). RESULTS: ARFI SS was the only non-invasive parameter associated with the presence of EV (2.7±0.30 vs. 3.4±0.52, p<0.001) and large EV (2.91±0.36 vs. 3.86±0.37, p=0.001) after multivariate logistic regression (p<0.001). ARFI SS for predicting EV showed an AUROC of 0.872 (CI 95%: 0.799-0.944), for a cut-off value of 2.89 m/s: Sensitivity (Se) 91.4% (CI 95%: 81-97%), Specificity (Sp) 67.7% (CI 95%: 51-85%). ARFI SS for diagnosing large EV (>5mm) had better results with an AUROC 0.969 (CI 95%:0.935-0.99), and for a cut-off of 3.30 m/s: Se 96.4% (CI 95%: 82-99.9%), Sp 88.5% (CI 95%: 78-95%). CONCLUSIONS: SS measured using ARFI is a good method of detecting EV and is an excellent method of diagnosing large EV in patients with virus-related cirrhosis.