Clinical Significance of Pulsatile High Pressure Zones on High Resolution Esophageal Manometry in Dysphagia Patients

Abstract

Introduction: Pulsatile high pressure zones (HPZ’s) are commonly seen in high resolution esophageal impedance manometry (HREIM) studies secondary to external association with thoracic cardiovascular structures (TCVS) and transmitted pulsations. The clinical significance of these findings is unclear in patients with dysphagia in terms of external CVS compression on esophagus. Methods: Retrospective review of 241 patients undergoing HREIM for dysphagia due to causes other than achalasia, stricture, esophageal dysmotility, mechanical obstruction, pharyngeal or esophageal pouch. The HRIM protocol included multiple 5 ml Gatorade swallows in both supine and upright swallows. Patients were identified based on findings of consistent pulsatile HPZ from either position with an average pressure of > 5mmHg. Further chart review was done for comparative radiology studies for TCV structures in anatomical esophageal proximity. Fifty patients with available radiology images (CT/MR chest, esophagogram) were identified. Manometric data were collected regarding number, location, width, pressure of HPZs from both postures. Esophageal clearance function identified by impedance was analyzed. Radiological imaging was reviewed to correlate with HREIM findings. Results: Among 241 patients (90F; 46M, Age 24-89 yrs), 136 (56.4%) were noted to have HPZ’s in either posture. Fifty of these 136 patients had at least one radiology comparison. A total of 70 HPZs were found in these 50 patients. Majority (39/70) of the HPZs were observed in both upright and supine postures, and 10 in upright, 16 in supine only. Only 3/50 patients had evidence of partial obstruction from TCVS compression on radiology (1 from aberrant subclavian artery with dysphagia lusoria, 2 from dilated left atrium). In the patient with dysphagia lusoria, bolus clearance was 10% in supine swallows and 90% upright swallows. In one of the patients with enlarged left atrium, bolus clearance was 80% in supine swallows and 10% in upright posture. No impedance data was available for the third patient. Pressure across HPZ in these 3 patients was from 25 to 35 mmHg. There was no radiological evidence of obstruction caused by TCVS in remaining 47/50 patients. Cross pressure of the HPZs ranged from 0-35mmHg (mean 9.96 mmHg). Impaired bolus clearance observed in 9/47 patients. Posture affected bolus clearance in these patients by >20% when HPZ became more prominent (supine vs upright). Conclusion: Pulsatile HPZ’s due to transmitted pulsations from TCV structures are frequently observed in HREIM; however, there was minimum clinical significance in most of the patients with dysphagia.