Interpretation of High Resolution Esophageal Manometry Interpretation: So near yet so far
Mayank Jain, Srinivas M, Piyush Bawane, Jayanthi Venkataraman.
Gleneagles Global Health City and SRIHER, Chennai, India
High Resolution esophageal manometry (HREM), using 16‐channel water‐perfused system has become the standard of care in supine posture for studying esophageal motility disorders. This is the most popular system that is currently available across several centres in the Indian subcontinent. Achalasia cardia and ineffective peristalsis are the 2 common types of motor abnormality across the Indian subcontinent.
We encounter 2 major referrals for study of HREM at the 2 centres. These are achalasia cardia for subtyping the type of achalasia and for patients who are proton pump dependent gastro esophageal refluxers and are being worked up for fundoplication. While Chicago Classification (CCv3.0) has made a major impact in diagnosis and management of incomplete lower esophageal relaxation (achalasia cardia and its subtypes) and major peristaltic abnormalities (spastic disorders of esophagus), we have major issues with interpretation of minor motility disorders especially ineffective peristalsis in patients with gastro esophageal reflux symptoms. There is a very poor correlation between clinical presentation and HREM findings. Should patients with ineffective peristalsis be subjected to fundoplication? We have not yet understood this. Use of Multiple Rapid Swallow (post-MRS contraction in IEM reflects the functional reserve of esophagus) has helped in assessing the influence of ineffective peristalsis in some of our patients with GER. Understanding the breaks in terms of length (2-5 cm and >5 cm) in transition zone and S2, S3 segment remains unfolded. Our study observed that large distal defects, rather than proximal breaks, had a greater impact on minor peristaltic abnormalities in patients with GER. What is not clear is whether abnormal distal contractile element is the primary defect in GERD or distal contractile abnormality is the resultant of long standing reflux.
The way forward: All along in the past decade we have been using CC derived normal values from western volunteers using solid‐state catheters. We have no normative data from India. For this very reason we for the first time reported normative data using this system in supine posture. Compared to CC v 3.0 we found a lower IRP and DCI, necessitating modification of CC cutoffs for this system for our patients. We are further researching normative data in upright posture (more physiological) and correlating the normatives with supine values.
In conclusion, while major advances have taken place in understanding the pathophysiology of swallow reflex using HREM, we have a far way to go ahead in understanding the clinical correlation of some of the unexpected findings in a clinical situation. Several questions remain unanswered. Will patients with ineffective peristalsis respond to prokinetics, can these patients be subjected to endoscopic or surgical anti reflux procedures. Can a single MRS study sequence suffice or is there a need for 3 or more sequential studies? Interpretation of HREM so near but yet so far.