Introduction
The Chicago Classification version 4.0©(CC4) provided an updated classification of oesophageal motility disorders based on high-resolution oesophageal manometry (HRM) findings[1-2]. A key modification included using solid swallows which have been shown to increase the diagnostic yield of oesophageal motility disorders[3]. CC4 fails to offer guidance on the weighting of relevant findings when wet and solid swallows are discordant[3]. Clinical judgement, such as incorporating patient reported symptoms, is therefore required when interpreting HRM findings[2-3].
Aims & Methods
This retrospective service evaluation aimed to determine the frequency of CC4 diagnostic discordance between wet and solid swallows and how this was managed clinically. Data was collected from consecutive patients at a single National Health Service Trust (UK) site over a 6-month period. HRM was performed using a 36-channel HRM solid state catheter with impedance (Medtronic ManoScan™ ESO HRM) following the upright study CC4 protocol[2]. All patients had 5 mL saline swallows and those with dysphagia or abnormal primary swallows underwent solid swallows (rice test meal)[3].
Results
69 patients underwent HRM during the 6-month period. 51 studies included solid swallows, 61% (n=31) showed agreement between wet and solid CC4 findings and 39% (n=20) showed disagreement. Of those with discordance, it was concluded that 9 were inconclusive due to mixed appearances. In 7 studies the solid swallows were deemed more clinically relevant and in 4 studies the liquids swallows best reflected the clinical context.
10 patients had abnormalities detected on wet swallows but normal solids, 50% of which showed ineffective oesophageal motility (IOM) and 50% showed oesophago-gastric junction outflow obstruction (OGJOO). Of the patients with OGJOO on wet swallows and normal solids, 3 were concluded to be normal due to a lack of symptoms, good bolus clearance on HRM and normal endoscopy and barium swallow results. One was deemed inconclusive as the patient was symptomatic to bolus hold-up measured on HRM. One was concluded as OGJOO due to abnormal rapid drink challenge, upright swallows and supine swallows.
Of the 5 studies showing IOM on liquid swallows but normal solids, 2 were overall concluded to be normal due to a lack of symptoms. 2 were concluded as IOM, although only one was symptomatic to ineffective swallows. Both reports did, however, mention evidence of peristaltic reserve. One study was concluded inconclusive as possible IOM.
3 patients who had normal liquid swallows had abnormalities on solids. One showed IOM on solids which was concluded as insignificant due to a lack of symptoms. One had hypercontractile oesophagus which was concluded as significant due to the presence of symptoms[3]. The other showed symptomatic OGJOO with solids. This was classed as inconclusive as the patient had normal bolus clearance on barium swallow.
Conclusion
More patients had abnormalities on liquid swallows which normalised on solids, despite studies indicating increased motility disorder diagnosis with solid swallows[4]. Test analysers placed greater significance on solid swallow findings compared to liquids. However, many tests were reported as inconclusive. Tests with abnormal liquid swallows but normal solids frequently had differing conclusions, in part due to adjunctive test findings and reported symptoms. This emphasizes the importance of symptoms and overall clinical judgement when reporting. Future CC iterations should consider discordant findings and offer guidance on what is clinically relevant during HRM studies.
References
[1] Yadlapati, R. Kahrilas, P.J. Fox, M.R. et al. 2021. Esophageal motility disorders on high-resolution manometry: Chicago classification version 4.0©. Neurogastroenterology and Motility. 33(1).
[2] Fox, M.R. Sweis, R. Yadlapati, R. Pandolfino, J. Hani, A. Defilippi, C. Jan, T. and Rommel, N. 2021. Chicago classification version 4.0© technical review: Update on standard high-resolution manometry protocol for the assessment of esophageal motility. Neurogastroenterology and Motility. 33(4).
[3] Ang, D. Misselwitz, B. Hollenstein, M. Knowles, K. Wright, J. Tucker, E. Sweis, R. and Fox, M. 2017. Diagnostic yield of high-resolution manometry with a solid test meal for clinically relevant, symptomatic oesophageal motility disorders: serial diagnostic study. The Lancet Gastroenterology & Hepatology. 2(9), 654-661.
[4] Sharma, P. and Yadlapati, R. 2022. Evaluation of Esophageal Motility and Lessons from Chicago Classification version 4.0. Current Gastroenterology Reports. 24(1):10-17.