Real-world Application of the Chicago Classification Version 4.0 for Esophageal Manometry: Asian Multicenter Study

The Chicago classification version 4.0 (CC v4.0) proposes a standardized high-resolution manometry protocol for more sophisticated diagnosis of esophageal motility disorders. We aim to investigate the real-world application of CC v4.0 through multi-institutional surveys in Asian countries.

We requested a total of 161 questionnaires from members of the Asian Neurogastroenterology and Motility Association via Google Survey from March to June 2023. The questionnaire assessed CC v4.0 protocol compliance and diagnosis.

Responses were received from 33 centers in 9 countries (18 in Korea, 5 in Japan, and 10 in others). Among these, anticholinergics were investigated in 14 centers (42.4%), and narcotic drugs in 16 centers (48.5%). Eight centers (24.2%) fully adhered to CC v4.0 protocol for single wet swallows and provocation tests. Nine centers (27.3%) had an adaptation period < 60 seconds, 13 centers (39.4%) had < 3 breath counts, and 15 centers (45.5%) had swallowing intervals < 30 seconds (42.4% had 10-29 seconds and 3% had < 10 seconds). Twenty-four centers (72.7%) started the examination in a supine position and 13 centers (39.4%) did not change their position. Among 27 centers (81.8%) applying provocation tests, all applied multiple rapid swallows, whereas rapid drink challenge was applied in 19 (57.6%). Timed barium esophagography and functional lumen imaging probe were available in 16 (48.5%) and 6 centers (18.2%), respectively.

We observed heterogeneity among centers in the application of CC v4.0 protocol. To increase inter-center reliability and minimize diagnostic ambiguity, efforts should continue toward the practical clinical application of standard protocols.