EndoFLIP-Guided Initial Management of Esophagogastric Junction Outflow Obstruction

O-FLIP is a prospective, multicenter, nonrandomized, single-arm interventional study evaluating an EndoFLIP-guided initial management strategy for esophagogastric junction outflow obstruction (EGJOO). Specialist esophageal motility units in Spain will enroll consecutive adults with clinically relevant dysphagia who meet the study eligibility criteria. Baseline data will include clinical characteristics, symptom scores, and findings from high-resolution manometry, timed barium esophagram, upper gastrointestinal endoscopy, and EndoFLIP panometry.

Participating centers will receive common training and use a standardized protocol for EndoFLIP acquisition and interpretation based on the Dallas Consensus. The treating endoscopist will interpret EndoFLIP findings in real time to guide initial management. The coordinating center will subsequently review coded recordings to assess measurement quality and agreement with the local classification.

Symptoms and scores on the Brief Esophageal Dysphagia Questionnaire (BEDQ) and Eckardt score will be recorded at 1, 3, 6, and 12 months, along with treatment changes, dysphagia recurrence, adverse events, and treatment escalation. Follow-up will start on the date of botulinum toxin administration for participants who receive it and on the date of the index endoscopy for those initially managed conservatively.

The primary analysis will estimate the proportion of participants with clinical response at 3 months in the overall cohort, with a 95% confidence interval. Outcomes will also be summarized by baseline EndoFLIP category. Secondary analyses will assess the durability of response and time to definitive treatment directed at the esophagogastric junction. Among participants who receive botulinum toxin, exploratory analyses will examine baseline clinical and physiological factors associated with an incomplete or transient response and with subsequent definitive treatment. Additional exploratory analyses will examine how baseline timed barium esophagram findings relate to EndoFLIP findings and clinical outcomes.

All participants will follow a standardized management algorithm based on esophagogastric junction (EGJ) opening on EndoFLIP panometry. Reduced opening will lead to botulinum toxin type A injection during the same endoscopy. Inconclusive or normal opening will lead to initial conservative management, which may include observation, proton pump inhibitors, neuromodulators, or calcium channel blockers at the treating physician's discretion.

Diagnostic Test: EndoFLIP Panometry · Drug: Botulinum Toxin Type A (BOTOX) Injection

EndoFLIP panometry will be performed during the index upper gastrointestinal endoscopy after mechanical causes of dysphagia have been excluded. The treating endoscopist will classify EGJ opening in real time according to standardized Dallas Consensus criteria. Coded recordings will subsequently undergo central review to assess measurement quality and agreement with the local classification.

Botulinum toxin type A will be injected endoscopically into the lower esophageal sphincter in participants with reduced EGJ opening. The treating physician will be responsible for prescribing and administering the injection as part of the EndoFLIP-guided management strategy.

Time frame: 3 months after botulinum toxin administration or, for participants initially managed conservatively, 3 months after the index endoscopy.

Proportion of participants in the overall cohort with at least a 50% reduction from baseline in the Brief Esophageal Dysphagia Questionnaire (BEDQ) total score. BEDQ scores range from 0 to 40, with higher scores indicating more severe dysphagia.

Time frame: Months 1, 6, and 12.

Proportion of participants with at least a 50% reduction from baseline in BEDQ total score.

Time frame: Baseline and months 1, 3, 6, and 12.

Change in BEDQ total score from baseline. Scores range from 0 to 40, with higher scores indicating more severe dysphagia.

Time frame: Baseline and months 1, 3, 6, and 12.

Change in Eckardt symptom score from baseline. Scores range from 0 to 12, with higher scores indicating greater symptom burden.

Time frame: Months 3 through 12.

Proportion of participants with a clinical response at month 3 who maintain at least a 50% reduction from baseline in BEDQ score through month 12 without recurrence.

Time frame: From the first documented response through month 12.

Proportion of participants with a previously documented clinical response who subsequently have a BEDQ reduction of less than 50% from baseline.

Time frame: Through month 12.

Proportion of participants who undergo pneumatic dilation, peroral endoscopic myotomy, or Heller myotomy after initial management, and time from the start of follow-up to the first such treatment.

Time frame: From the index endoscopy through month 12.

Proportion of participants with at least one adverse event associated with endoscopy, EndoFLIP, or treatment. Event severity will be reported using the AGREE classification, from grade I to V

Time frame: Index endoscopy, with subsequent central review of the same recording.

Agreement on EGJ opening category (reduced, inconclusive, or normal), quantified using Cohen's kappa with a 95% confidence interval.

Prospective Evaluation of an Impedance Planimetry-Guided Therapeutic Stratification Algorithm in Patients With Esophagogastric Junction Outflow Obstruction After Endoscopic Assessment: O-FLIP Multicenter Study