Use of Esophageal String Test to Understand Symptoms, Inflammation, and Function in Eosinophilic Esophagitis
Condition: Eosinophilic Esophagitis
MeSH terms: Esophagitis; Eosinophilic Esophagitis; Inflammation
Study type: Interventional

Summary: 
      Presently, the only method available to monitor disease activity in Eosinophilic Esophagitis
      (EoE) is endoscopy with pathological review of biopsies. The overall goal of this study is to
      determine the ability of the Esophageal String Test (EST), a minimally invasive capsule based
      technology, to measure disease activity in children with EoE. Additionally, to determine
      esophageal distensibility in children presenting with EoE by using the EndoFLIP (functional
      luminal imaging probe) device during endoscopic procedures.
    

Detailed description: 
      When children are scheduled to undergo an endoscopy, research assistants will contact the
      family to arrange for the Esophageal String Test (EST) to be performed within one week of the
      endoscopy. The string test involves swallowing a small capsule with a thin piece of string
      inside it. The string unravels as the capsule goes down into the stomach. The investigator
      would tape the end of the string to the child's cheek, leaving it there for one hour. At the
      end of the hour, the investigator would remove the string by gently pulling it out through
      the mouth. Prior to swallowing the EST, the patient will complete the PEESS form (Pediatric
      Eosinophilic Esophagitis Symptom Scores) to assess symptoms.

      The endoscopy and Endoscopic Reference System (EREFs) and EndoFLIP will be performed. The
      EndoFLIP is a slender probe covered by a smooth long balloon that is passed into the
      esophagus and slowly expanded with a salt solution. After standard of care endoscopic
      visualization, the FLIP, a 16 cm probe (Crospon) will be placed transorally and positioned 3
      cm distal to the lower esophageal sphincter. Esophageal cross sectional areas and intrabag
      pressure will be measured during stepwise distensions beginning with 5 mL and increasing to a
      maximum of 70mL or intrabag pressure of 50 mmHg is achieved, whichever comes first. FLIP is
      FDA-approved without age restriction and its use has been approved by our IRBs previously.
      Primary results will be reported as distensibility plateau (mm).

      Endoscopic severity: Endoscopic esophageal appearances will be scored using a validated EoE
      scoring system (EREFS). Five features of EoE will be scored: Edema (0-1), Rings (0-3)
      Exudates (0-2), Furrows (0-1), Stricture (0-1). Results will be reported as an inflammatory
      score (edema, exudates, furrows) and fibrostenotic score (rings, stricture). Functional
      Luminal Imaging Probe (FLIP):
    

Intervention name(s): Esophageal String Test (EST)
Intervention type(s): Device
Intervention description(s): The EST is a gelatin capsule filled with a 90cm nylon string. A trailing end of the string protrudes from one end of the capsule. This end is taped to the cheek and the capsule is swallowed. As the capsule travels to the small intestine, the string inside the capsule is dislodged, leaving a string that goes from the cheek to the small intestine. The capsule dislodges from the string and the string is left in place, in the mouth, esophagus, stomach and small intestine for an hour. During this time, the string rubs against the inside of the esophagus and collects eosinophil proteins. After one hour, the string is removed through the mouth and placed in preservative to save the eosinophil proteins.
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Pediatrics