EndoFLIP® in Comparison to High-Resolution Manometry and Eckardt Score in the Assessment of Achalasia Prior to Intervention

Abstract

Introduction: Achalasia is defined by manometry that demonstrates aperistalsis of the esophageal body and incomplete relaxation of the lower esophageal sphincter (LES). The purpose of this study is to compare the EndoFLIP (FLIP) to high resolution manometry (HRM) and Eckardt score (ES) in the initial assessment of achalasia. Methods: Twenty-one patients with achalasia were enrolled at a single tertiary center. For each patient, diagnostics included: ES, HRM, and FLIP. The FLIP system is catheter based with a distal 14cm probe containing 17 electrodes, each 5mm apart and designed to make impedance planimetry measurements. Once the bag is filled to 40cc, distensibility index (DI), cross-sectional area (CSA), balloon pressure, and minimum diameter are measured at the most narrow point. Results: The patients had a mean age of 59 years and BMI of 26.3 + 1.4 Kg/M2. The mean ES across all patients was 7.0 + 2.9. The mean LES pressure was 37.8 + 5.1 mmHg and the residual LES pressure was elevated at 25.9 + 12.1 mmHg with incomplete relaxation. There were 9 patients with type 1 achalasia, 8 patients with type 2 achalasia, and 4 patients with type 3 achalasia. Using FLIP, the CSA was 54.2 + 9.7mm2 and the minimum diameter was 7.8 + 0.7mm. The mean distensibility in the patients was 1.6 + 1.3 mm2/mmHg. There was poor correlation between the ES and DI (r= -0.22; p= 0.34 ). However, the LES residual pressure and DI were significantly inversely correlated (r= -0.44; p= 0.047). The number of patients was insufficient to show variations in results between achalasia subtypes. Conclusion: This study shows 1) DI is decreased, showing decreased stretch, in symptomatic patients with achalasia and 2) the DI correlated significantly with residual LES pressure, but not symptoms. Thus the DI can be used as a parameter to monitor therapy of achalasia. Conclusion: Distensibility is a useful tool to assess achalasia, correlating with ES and correlating significantly with LES residual pressure in the pre-intervention assessment of achalasia.