S496 A Comparison of Manometric and Functional Lumen Impedance Planimetry (FLIP) Diagnoses of Esophageal Dysmotility

Abstract

Introduction: Functional lumen impedance planimetry (FLIP) has been utilized extensively as an adjunct to high resolution impedance manometry (HRIM) for evaluating disorders of esophageal dysfunction. HRIM and FLIP provide valuable metrics that provide similar but distinct information about esophageal function, resulting in similar but distinct diagnoses. For both tools to be used in parallel to diagnose esophageal disorders, it is imperative to understand concordance rate of diagnoses between the two studies.The aim of this study is to evaluate the extent of agreement between FLIP and HRIM diagnoses by constructing parallels between diagnoses made by FLIP and HRIM on patients who underwent both studies and evaluating whether the modalities aligned by more than random chance. Methods: A retrospective review of 227 patient charts was performed. Pairs of similar HRIM and FLIP diagnoses pertaining to peristaltic and aperistaltic conditions were formed by comparing and correlating the criteria for each diagnosis by HRIM to criteria by FLIP. Diagnoses without a correlation were designated “other.” The number of patients whose FLIP and HRIM diagnoses were and were not in agreement was recorded for each diagnosis pair. Results: Table shows the specific HRIM and FLIP diagnoses that were correlated, the number of the patients in which their diagnoses by HRIM and FLIP represent the same condition, and the percentage of the patients with each HRIM diagnosis that had the predicted correlating FLIP diagnosis.The overall percentage in agreement among all diagnoses was 26%. Cohen’s Kappa of agreement for all studies was statistically significant at 0.121 (p < 0.0001). When “other” diagnoses without matching diagnoses between HRIM and FLIP were omitted from analysis, agreement increased to 33.5%. Cohen’s Kappa of agreement for paired diagnoses was statistically significant at 0.157 (p < 0.0001). Conclusion: Our study found that FLIP testing agreed with manometric diagnosis more often than random chance would predict, but only 26% of the time. The studies are therefore slightly predictive of one another, though imperfectly. The tools analyze different aspects of esophageal physiology to arrive at their diagnoses. This both complicates direct pairing of diagnoses and also provides each modality a unique role in assessing esophageal dysmotility. These findings support that HRIM and FLIP testing may be considered complementary tools to utilize in parallel for patients with suspected esophageal dysmotility. Table 1. - Correlated HRIM (High Resolution Impedance Manometry) and FLIP (Functional Lumen Impedance Planimetry) Diagnoses and Their Agreement Rates HRIM Diagnosis Correlating FLIP Diagnosis Number in Agreement Percent of Total in Agreement Normal Normal 7 41.2% Diffuse Esophageal Spasm Normal Distensibility with Repetitive Retrograde Contractile Response 0 Undefined Type 1 Achalasia EGJOO with Absent Contractile Response 14 77.8% Type 3 Achalasia EGJOO with Repetitive Retrograde Contractile Response 5 33.3% EGJOO EGJOO with Normal Contractile Response 29 25.7% Aperistalsis Normal Distensibility with Absent Contractile Response 2 33.3% Other (Jack Hammer, Ineffective Esophageal Motility, Type 2 Achalasia, Fragmented Peristalsis) Other (Normal Contractile Response with Increased EGJ Distensibility, Absent Contractile Response with Increased EGJ Distensibility, Diminished or Disordered Contractile Response) 1 1.9% EGJ - Esophagogastrojejunal, EGJOO - Esophagogastrojejunal Outflow Obstruction)