Shunsuke Akimoto, Saurabh Singhal, Sumeet K Mittal. Creighton University Medical Center
Introduction: Chicago classification has recently added morphological sub-classification for Lower esophageal sphincter complex. Aim of this study to discuss and hypothesize esophagogastric junction (EGJ) morphology as assessed by high-resolution manometry (HRM) and its association with reflux. We assessed esophageal reflux in patients with Chicago EGJ-Type 3a and 3b.
Methods: After IRB approval, from a prospectively collected HRM database, we identified patients who underwent pH study between Oct 2011 and Jun 2015 and were diagnosed with EGJ-Type 3. Chicago EGJ-Type3 is defined as the inter-peak nadir pressure ≤ gastric pressure and LES-CD separation ≥2 cm [3a- PIP (pressure inversion point) remains at the CD level, 3b-PIP remains at the LES level]. We excluded the patients with prior foregut intervention, esophageal dysmotility, LES-CD >5cm or if 24-hour pH study was done on acid suppressions. We classified the patients into reflux group [DeMeester score > 14.72 or Fraction time pH (<4) >4.2%] and no reflux group.
Results: Fifty patients satisfied study criteria, of which 37 patients (74%) were type 3a. Abdominal LES length (AL) in reflux group was significantly shorter than no reflux group (0.1 vs. 0.9 p=0.003). While overall LES length (OL), LES pressure (LESP), LESP integral (LESPI), Integrated relaxation pressures (IRP) and Distal contractile integral (DCI) were not significantly different between reflux and no-reflux groups. The pH study was more commonly positive in LES-CD ≥3cm than in LES-CD <3 cm (85% vs. 56.7%, p=0.046). Type 3a patients showed significantly higher values of DeMeester score, Fraction time pH and the positive pH study than type 3b (DeMeester score: 36.4 vs. 16.1 p=0.005, Fraction time: 10.1 vs.4.3 p=0.003, positive pH study: 81.1% vs. 30.8% p <0.001). In type 3b, AL in the reflux group was significantly lower than the no reflux group (0.9 vs. 1.6 p=0.021).
Conclusion: A subset of patients with LES-CD separation maintain a physiological intra-abdominal location of EGJ (type 3b) and hence are less likely to have reflux. LES-CD ≥3cm seems to discern a hiatus hernia of clinical significance.