Most patients with normal findings on functional luminal imaging probe (FLIP) showed no clinical evidence of a major esophageal motor disorder, even when their high-resolution manometry (HRM) test results were abnormal, according to the results of a single-center retrospective cohort study.
Among 111 study participants with normal FLIP findings, 79% also showed no evidence of a major esophageal motor disorder on esophageal high-resolution manometry (HRM), wrote Alexandra J. Baumann, DO, of Northwestern University, Chicago, and associates. “Among the remaining 21% with apparent disagreement with HRM, [those] with normal FLIP panometry carried overall clinical impressions of not having a major esophageal motor disorder and subsequently were treated conservatively without the need for surgical interventions,” they reported. For patients with normal upper endoscopy and normal FLIP panometry, “the initial clinical management strategy could be directed toward addressing gastroesophageal reflux or a functional syndrome,” they wrote in.
FLIP uses high-resolution impedance planimetry to evaluate esophageal lumen parameters, distensibility, and contractility in response to distension. Although HRM is standard for evaluating esophageal motility, false negatives and positives can result from challenges with interpreting outflow obstructions and normal lower-esophageal sphincter relaxation pressures among patients with clinical achalasia.
Hence, the researchers evaluated correlations between FLIP and HRM in 111 patients with esophageal symptoms and nonobstructive endoscopy findings who were evaluated at the Esophageal Center of Northwestern University between 2012 and 2019. Gastroenterologists performed additional studies, such as barium esophagrams, at their discretion. By study design, all patients had normal FLIP results, defined as an esophagogastric junction distensibility index above 3.0 mm2 per mm Hg and a normal contractile response (that is, normal repetitive retrograde contractions and a repetitive antegrade contraction pattern that met the Rule-of-6s). Three clinicians evaluated and reached consensus on each FLIP study. Esophageal HRM data were interpreted based on the Chicago classification system (version 3.0).
Patients with normal FLIP panometry findings “did not have a clinical impression of a major esophageal motor disorder,” the researchers reported. In all, 23 (21%) patients with normal FLIP results had discrepant (abnormal) HRM findings, most of which were false positives or equivocal.
For example, among 20 patients whose HRM suggested an esophagogastric junction outflow obstruction, 17 showed normal bolus transit on supine swallows and 16 showed normalization of integrated relaxation pressure after adjunctive maneuvers. Similarly, among 10 patients who underwent a barium esophagram, 8 showed normal emptying, 1 showed a temporary delay but no retention, and 1 had an incomplete study. “The overall clinical impression was not of an achalasia variant in any of these 20 patients with [esophagogastric junction outflow obstruction] on HRM, and thus none underwent botulinum toxin injection, pneumatic dilation, or lower-esophageal sphincter myotomy at our center,” the researchers wrote. Among 17 patients who were available for clinical follow-up, 4 underwent empiric dilation, of whom none had mucosal disruption. One patient was diagnosed with dysphagia lusoria based on cross-sectional imaging, while the rest were managed conservatively.
Similarly, among 10 patients with at least 50% ineffective swallows on HRM, 5 showed normal barium emptying and 9 were managed conservatively (the remaining patient underwent cricopharyngeal dilation for concurrent oropharyngeal dysphagia). The strong correlation between HRM and esophagrams in this study indicates that“[n]ormal findings from FLIP panometry can be used to exclude esophageal motility disorders at the time of endoscopy, possibly reducing the need for high-resolution manometry evaluation of some patients,” the investigators concluded. “However, further longitudinal studies are needed to support this approach.”
The work was supported by the Public Health Service and the American College of Gastroenterology. Dr. Baumann reported having no conflicts of interest. Four coinvestigators disclosed relevant ties to Crospon, Given Imaging, Ironwood, Medtronic, Sandhill Scientific, Torax, and other companies..
SOURCE: Baumann AJ et al. Clin Gastroenterol Hepatol 2020 Mar 20.