(through colonoscopy) gastrointestinal tract. Many bleeding lesions have been successfully clipped, including bleeding peptic ulcers, Mallory-Weiss tears of the esophagus, Dieulafoy's lesions, stomach tumours, and bleeding after removal of polyps. Bleeding peptic ulcers require endoscopic treatment if they show evidence of high risk stigmata of re-bleeding, such as evidence of active bleeding or oozing on endoscopy or the presence of a visible blood vessel around the ulcer. The alternatives to endoscopic clipping of peptic ulcers are thermal therapy (such as electrocautery to burn the vessel causing the bleeding), or injection of epinephrine to constrict the blood vessel. Comparative studies between endoclips and thermal therapy make the point that endoclips cause less trauma to the mucosa around the ulcer than electrocautery, but no definitive advantage to either approach has reached consensus by gastroenterologists. Other applications Endoclips have also found an application in preventing bleeding when performing complicated endoscopic procedures. For example, prophylactic clipping of the base of a polyp has been found to be useful in preventing post-polypectomy bleeding, especially in high-risk patients or patients on anticoagulant medications. In addition, clips can be used to close gastrointestinal perforations that may have been caused by complicated therapeutic endoscopy procedures, such as polypectomy, or by the endoscopic procedure itself. Clips have also been used to secure the placement of endoscopic feeding tubes, and to orient the bile duct to assist with endoscopic retrograde cholangiopancreatography, a procedure used to image to bile duct. Safety Endoclips have been seen to dislodge between 1 and 3 weeks from deployment, although lengthy clip retention intervals of as high as 26 months have been reported. Endoclips are believed to be safe and no major complications (such as perforation or impaction) have been reported with them, although concern has been raised about blocking the outflow of the bile duct if clips are deployed in the duodenum. References Gastroenterology Implants (medicine) Endoscopy