Prospective cross‐organ analysis for the causes of fever and increased inflammatory response after endoscopic resection

Objectives Fever and increased inflammatory responses sometimes occur following endoscopic resection (ER). However, the differences in causes according to the organ are scarcely understood, and several modified ER techniques have been proposed. Therefore, we conducted a comprehensive prospective study to investigate the cause of fever and increased inflammatory response across multiple organs after ER. Methods We included patients who underwent gastrointestinal endoscopic submucosal dissection (ESD) and duodenal endoscopic mucosal resection at our hospital between January 2020 and April 2022. Primary endpoints were fever and increased C‐reactive protein (CRP) levels following ER. The secondary endpoints were risk factors for aspiration pneumonia. Blood tests and radiography were performed on the day after ER, and computed tomography was performed if the cause was unknown. Results Among the 822 patients included, aspiration pneumonia was the most common cause of fever and increased CRP levels after ER of the upper gastrointestinal tract (esophagus, 53%; stomach, 48%; and duodenum, 71%). Post‐ER coagulation syndrome was most common after colorectal ESD (38%). On multivariate logistic regression analysis, lesions located in the esophagus (odds ratio [OR] 3.57; P < 0.001) and an amount of irrigation liquid of ≥1 L (OR 3.71; P = 0.003) were independent risk factors for aspiration pneumonia. Conclusions Aspiration pneumonia was the most common cause of fever after upper gastrointestinal ER and post‐ER coagulation syndrome following colorectal ESD. Lesions in the esophagus and an amount of irrigation liquid of ≥1 L were independent risk factors for aspiration pneumonia.