VALIDATION OF FLIP PANOMETRY ESOPHAGEAL MOTILITY CLASSIFICATION: A STUDY OF 558 NEW PATIENTS WITH MANOMETRY

BACKGROUND: A scheme for classifying esophageal motility using Functional Lumen Imaging Probe (FLIP) Panometry that paralleled high-resolution manometry (HRM) was previously developed and described in a study of 722 subjects. This study aimed to further assess and validate that classification scheme on a cohort of 558 new patients and evaluate it against HRM and Chicago Classification v4.0 (CCv4.0).
METHODS: 558 adult patients (mean age 54 (SD 17) years; 62% female) evaluated for esophageal symptoms via upper endoscopy with FLIP and HRM eligible for CCv4.0 were included. The primary analysis included 472 patients with a conclusive CCv4.0 diagnosis, with timed barium esophagram (TBE) applied to define conclusive esophagogastric junction (EGJ) outflow obstruction (EGJOO). TBE findings relative to FLIP were also described among all EGJOO on HRM. EGJ opening (applying 60ml EGJ distensibility index and maximum EGJ diameter) and contractile response (CR) to distension (i.e. secondary peristalsis) were evaluated with a 16-cm FLIP during sedated endoscopy and analyzed using a customized software program.
RESULTS: In the primary analysis (Figure 1), 105 patients had normal motility on FLIP Panometry (defined by normal EGJ opening and normal or borderline CR): 91% had normal motility or ineffective esophageal motility on HRM. 146 patients had obstruction with weak CR (defined by reduced EGJ opening with absent or impaired/disordered CR): 89% had a conclusive disorder of EGJ outflow per CCv4.0. Further, among manometric EGJOO (inconclusive), there was a significant association with retention on TBE (P=0.020), with 73% of normal FLIP having a normal TBE while 80% of obstruction with weak CR on FLIP having retention on TBE (Figure 2). TBE was not available in 39 EGJOO.
DISCUSSION: Classifying esophageal motility by FLIP Panometry continued to parallel swallow-associated motility evaluation on HRM +/- TBE per CCv4.0 in this new cohort of patients. This further validates the utility of FLIP Panometry as a well-tolerated method done during sedated endoscopy to complement or replace HRM for evaluating esophageal motility disorders.