Disease Management Endoscopy, Gastrointestinal Humans Intestinal Perforation Postoperative Complications Practice Guidelines as Topic Vater papilla stenosis adult air embolism ampicillin article biliary tract endoscopy case report cholangitis clip colonoscopy complication computer assisted tomography conscious sedation dysphagia endoscopic complication endoscopic retrograde cholangiopancreatography endoscopy esophagoscopy esophagus perforation female fluoroscopy human inferior cava vein male