Esophageal dysmotility according to Chicago classification v3.0 vs v2.0: Implications for association with reflux, bolus clearance, and allograft failure post-lung transplantation

Background: Proximal reflux and incomplete transit of boluses swallowed are risk factors for obstructive chronic lung allograft dysfunction (o-CLAD) post-lung transplantation (LTx). Likewise, so is esophagogastric junction outflow obstruction (EGJOO), but not hypo-contractility, when diagnosed using Chicago Classification (CC) v3.0. Given, peristaltic breaks as defined using CCv2.0 can prolong esophageal clearance, both swallowed and refluxed, but which are deemed within normality using CCv3.0, our aim was to determine whether hypo-contractility as diagnosed using CCv2.0, influences the association with reflux, along with its clearance, and that of boluses swallowed, and thus its association to allograft failure. Methods: Esophageal motility abnormalities were classified using CC v3.0 and v2.0 in 50 patients post-LTx (26 female, 55 years (20-73 years)). Results: Reclassification from CCv3.0 to v2.0 resulted in 7 patients with normal motility being reclassified to hypo-contractility (n = 6) or hyper-contractility (n = 1); 2 patients with hypo-contractility to normal motility; and 3 patients with EGJOO without hyper-contractility to EGJOO with hyper-contractility. The main consequence of reclassification was that the sub-group exhibiting hypo-contractility became more likely to have abnormal numbers of reflux events (P =.025) and incomplete bolus transit (P =.002) than those with normal motility using CCv2.0; associations not seen using CCv3.0. Irrespective of CC used only patients with EGJOO appeared more likely to develop o-CLAD than those with normal motility (P <.05). Conclusions: Irrespective of CC used, o-CLAD appears linked to EGJOO. CCv2.0 however, accentuates the increased reflux and incomplete bolus transit associated with hypo-contractility post-LTx, suggesting that these motor abnormalities, though considered minor, may be of importance after lung transplant.