Discriminating "impaired" from "disordered" contractile response on FLIP panometry by utilizing pressure measurement.

ABSTRACT

BACKGROUND: Functional lumen imaging probe (FLIP) panometry evaluates esophageal motility, including the contractile response to distension, that is, secondary peristalsis. Impaired/disordered contractile response (IDCR) is an abnormal, but nonspecific contractile response that can represent either hypomotility or spastic motor disorders on high-resolution manometry (HRM). We hypothesized that FLIP pressure could be incorporated to clarify IDCR and aimed to determine its utility in a cohort of symptomatic esophageal motility patients. METHODS: 173 adult patients that had IDCR on FLIP panometry and HRM with a conclusive Chicago Classification v4.0 (CCv4.0) diagnosis were included and analyzed as development (n = 118) and validation (n = 55) cohorts. FLIP pressure values were assessed for prediction of either hypomotility or spasm, defined on HRM/CCv4.0. KEY RESULTS: HRM/CCv4.0 diagnoses were normal motility in 48 patients (28%), "hypomotility" (ineffective esophageal motility, absent contractility, or Type I or II achalasia) in 89 (51%), and "spasm" (Type III achalasia, distal esophageal spasm, or hypercontractile esophagus) in 36 (21%). The pressure at esophagogastric junction-distensibility index (DI) (60 mL) was lower in hypomotility (median [interquartile range] 34 [28-42] mmHg) than in spasm (49 [40-62] mmHg; p < 0.001) and had an area under the receiver operating characteristic curve of 0.80 (95% CI 0.73-0.88) for hypomotility and 0.76 (0.69-0.83) for spasm. For "spasm" on HRM, a threshold FLIP pressure of >35 mmHg provided 90% sensitivity (47% specificity) while >55 mmHg provided 93% specificity (40% sensitivity). CONCLUSION & INFERENCES Pressure on FLIP panometry can help clarify the significance of IDCR, with low-pressure IDCR associated with hypomotility and high-pressure IDCR suggestive of spastic motor disorders.