RA06.01: PATHOLOGICAL IMPLICATIONS OF SWALLOW-ASSOCIATED TRANSIENT LOWER ESOPHAGEAL SPHINCTER ELEVATION

Background We have previously reported that swallow-induced transient hiatal hernia (tHH) is associated with pathological gastroesophageal reflux. In this study, we built upon our previous study of tHH, assessing the pathological implications of swallow-induced tHH in a new, larger cohort. Methods We queried a prospectively maintained database to identify patients who underwent both 24-hour pH monitoring and high-resolution manometry (HRM) between January 2017 and December 2017. We excluded patients with end-stage lung disease, inadequate LES relaxation, major esophageal motility disorders, or manometric hiatal hernia. Significant swallow-induced LES–CD separation was defined as ≥ 1 cm separation in ≥ 30% swallows or ≥ 2 cm separation in ≥ 10% swallows. We used HRM to separate patients into 3 groups, as follows: 1. Persistent tHH (p-tHH): Significant LES–CD separation at the 2nd inspiration after the conclusion of swallow-induced esophageal peristalsis. 2. Incident tHH (i-tHH): Significant LES–CD separation at the 1st inspiration after the conclusion of peristalsis without meeting p-tHH criterion. 3. Non-tHH: Neither p-tHH nor i-tHH was observed. Results In total, 472 patients underwent both HRM and a 24-hour pH study during the study period. Of these, 74 patients met inclusion criteria. The mean age was 51.6 years, and 45 patients (60.8%) were women. Forty-two patients (56.8%) had an abnormal DeMeester score (ie, > 14.72). Fourteen patients (18.9%) were categorized into the p-tHH group, 36 (48.6%) were in the i-tHH group, and 24 (32.4%) were in the non-tHH group. LES pressure, LES pressure integral, esophageal peristaltic vigor, and prevalence of dysmotility were similar among the groups. No significant differences were observed in the pH studies for patients with i-tHH and non-tHH; however, patients in the p-tHH group had a higher prevalence of abnormal DeMeester score and longer total acid reflux time than patients in the non-tHH cohort (78.6 vs 45.8%, P < 0.05; 8.0 vs 3.8%, P = 0.016, respectively). Conclusion We confirm that p-tHH is associated with pathological distal esophageal acid exposure and appears to be an early indicator of LES dysfunction. Disclosure All authors have declared no conflicts of interest.