UC San Diego

Background

Type II achalasia (Ach2) is distinguished from other achalasia sub-types by the presence of panesophageal pressurization (PEP) of ≥30 mmHg in ≥20% swallows on high-resolution manometry (HRM). Variable manometric features in Ach2 have been observed, characterized by focal elevated pressures (FEPs) (focal/segmental pressures ≥70 mmHg within the PEP band) and/or high compression pressures (PEP ≥70 mmHg). This study aimed to examine clinical and physiologic variables among sub-groups of Ach2.

Methods

This retrospective single center study performed over 3 years (1/2019-1/2022) included adults with Ach2 on HRM who underwent endoscopic ultrasound (EUS), functional lumen imaging probe (FLIP), and/or barium esophagram (BE) prior to therapy. Patients were categorized into two overarching sub-groups: Ach2 without FEPs and Ach2 with FEPs. Demographic, clinical, and physiologic data were compared between these sub-groups utilizing unpaired univariate analyses.

Key results

Of 53 patients with Ach2, 40 (75%) were without FEPs and 13 (25%) had FEPs. Compared with the Ach2 sub-group without FEPs, the Ach2 sub-group with FEPs demonstrated a significantly thickened distal esophageal circular muscle on EUS (1.4 mm [SD 0.9] vs. 2.1 [0.7]; p = 0.02), higher prevalence of tertiary contractions on BE (46% vs. 100%; p = 0.0006), lower esophagogastric junction distensibility index (2.2mm² /mmHg [0.9] vs 0.9 [0.4]; p = 0.0008) as well as higher distensive pressure (31.0 mmHg [9.8] vs. 55.4 [18.8]; p = 0.01) at 60 cc fill on FLIP, and higher prevalence of chest pain on Eckardt score (p = 0.03).

Conclusions and inferences

We identified a distinct sub-group of type II achalasia on HRM, defined as type II achalasia with focal elevated pressures. This sub-group uniquely exhibits spastic features and may benefit from personalized treatment approaches.