S4232 Megaesophagus Causing Respiratory Failure: Diagnosis of Achalasia via EndoFLIP™

Introduction: Achalasia is characterized by impaired relaxation of the lower esophageal sphincter and aperistalsis of the distal 2/3 of the esophagus. It can progress to esophageal dilation and megaesophagus (diameter >6 cm) in ∼ 10% of patients. This can cause severe dysphagia, regurgitation, chest pain, and weight loss. Management depends on classifying achalasia into 1 of 3 phenotypes and thereafter assessing patient candidacy for surgical or endoscopic intervention. We present a case of a patient with cough and weight loss, who was found to have megaesophagus causing recurrent aspiration and acute respiratory failure, later diagnosed with type I achalasia on EndoFLIP™. Case Description/Methods: A 69-year-old with achalasia presented with 2 days of dyspnea and 3 weeks of productive cough. He lost 15 pounds in 4 months after starting Tirzepatide. His achalasia was diagnosed 30 years earlier with manometry, but he was unsure of which subtype, and it was unsuccessfully treated with 1 attempt at balloon dilatation. On arrival, the patient was in respiratory distress: tachypneic to 28, hypoxic to 91%, and confused. He was intubated; a computed tomography angiogram ruled out pulmonary embolism but showed a right lower lobe mucus plug and a fluid-filled and massively dilated esophagus to >7 cm. Endoscopy was performed which revealed a dilated fluid filled esophagus with retained food. An endoscopic PEG-J was then placed to prevent further aspiration. He was extubated and planned for outpatient follow up for further achalasia evaluation and management, however he returned 1 month later with G-J dislodgement, and underwent esophagogastroduodenoscopy with EndoFLIP™ which revealed at 60 ml the distensibility index was 1.3-1.5 mm2/mmHg [normal >2] and the diameter was 6.8-7.2 mm. [normal >16 mm]. No peristalsis was visualized. At 70 ml the diameter was 10.5-11.1 mm. The patient was diagnosed with type I achalasia and planned for Heller myotomy. Discussion: Esophageal pathology should be considered in patients with unexplained respiratory symptoms. His weight loss was attributed solely to tirzepatide, however, it could have been exacerbated by achalasia. Type I achalasia was diagnosed solely on EndoFLIP™ and patient is planned for appropriate treatment based on subtype, raising the question of whether manometry is truly necessary for diagnosis when EndoFLIP™ is available. More studies need to be performed to elucidate this. Timely interventions for achalasia can prevent progression of disease and therefore reduce morbidity and improve outcomes.