Acute Intraoperative Airway Emergency During Submucosal Tunnel Endoscopic Resection for an Esophageal Lesion: A Report of an Unusual Case.

BACKGROUND Endoscopic gastrointestinal surgery rarely leads to airway compromise, but when mediastinal emphysema or pneumoperitoneum caused by perforation occurs, it can result in acute respiratory failure under anesthesia. Since the underlying mechanisms differ from those of typical pulmonary causes, reporting such rare cases is valuable for raising awareness among anesthesiologists and clinicians, and for emphasizing the importance of understanding surgical progress and performing timely physical examinations. CASE REPORT A 60-year-old woman with a submucosal esophageal mass underwent submucosal tunnel endoscopic resection (STER). During the procedure, a critical event occurred: airway pressure surged and effective ventilation nearly ceased, manifesting as hypoxemia and hypotension. Physical examination revealed marked abdominal distension with elevated intra-abdominal pressure. Concurrent intraoperative observation identified a perforation in the lower esophagus. The diagnosis was an esophageal perforation leading to pneumoperitoneum-induced abdominal compartment syndrome, which caused thoracic compression and acute respiratory failure. Emergency management included halting the procedure and CO₂ insufflation, followed by immediate abdominal decompression. These interventions promptly restored adequate ventilation and stabilized hemodynamics. CONCLUSIONS Esophageal perforation during lower esophageal tumor dissection can permit gas to escape into the abdominal cavity, leading to abdominal compartment syndrome and subsequent thoracic compression. This cascade can rapidly progress to severe hypoventilation and hypoxemia. Awareness of this rare but potentially fatal complication is crucial, and timely recognition with prompt management is essential to improving patient safety during gastrointestinal surgery.