We reported pneumoperitoneum due to PEG bumper dislodgement during ESD in a PEG patient. We initially suspected mediastinal emphysema caused by esophageal perforation because of the sudden intraoperative changes in circulatory and respiratory status. However, postoperative CT showed PEG bumper dislodgement and a large amount of intra-abdominal gas accumulation. We concluded that it was highly likely that the insufflation gas in the surgical field had accumulated in the stomach, leaked into the abdominal cavity through the gastrostomy hole, and caused mediastinal emphysema via the esophageal hiatus. We believe that this increase in insufflation pressure may have exacerbated the patient’s respiratory depression. Pneumoperitoneum is a complication that occurs in as many as 50% of patients after PEG placement , but to our knowledge, there are no reports of PEG bumper dislodgement and pneumoperitoneum during esophageal ESD in PEG patients. Complications arising from CO2 insufflation include pneumothorax, mediastinal emphysema, and subcutaneous emphysema . Pathways of CO2 gas leakage from the abdominal cavity to the thoracic cavity include surgically induced medically induced fistulae and diaphragmatic anatomy (e.g., esophageal hiatus and vena caval foramen) .
In the case of laparoscopic surgery, factors that increase the likelihood of subcutaneous emphysema, pneumothorax, and mediastinal emphysema include the flow rate and pressure of the delivered gas, and the gas usage should be recorded .
Several improvements can be made: First, in endoscopic esophageal surgery, we believe that the flow rate and pressure of the insufflation gas as well as the amount of gas used should be recorded as in laparoscopic surgery, because in PEG patients, air accumulation in the stomach may cause the PEG bumper dislodgement, resulting in pneumoperitoneum.
Second, intraoperative measures such as keeping the PEG button open or inserting a tube for degassing from the PEG may be useful to prevent PEG bumper dislodgement by reducing the increase in intragastric pressure.
Third, it is important to remember that there is a possibility that the insufflation gas leaked into the abdominal cavity when the PIP, HR, and end-tidal CO2 (ETCO2) began to rise. In esophageal endoscopy, it is advisable to consider the possibility of subcutaneous emphysema, pneumothorax, or mediastinal emphysema when PIP, HR, and ETCO2 are elevated.