This study is designed as a multicenter prospective data recording study to document the performance of the DAT clip as part of standard medical care of patients. No experimental interventions will be performed.

Endoscopic clipping devices are instruments designed to achieve tissue approximation during gastrointestinal endoscopy. Although endoscopic clips were initially developed for the primary purposes of accomplishing hemostasis of focal gastrointestinal bleeding, the indications for endoscopic clipping have expanded to include closure of perforations and fistulas, securing positioning of catheters and stents as well as to provide a radio-opaque markers to direct endoscopic, radiological, and surgical therapy.

Traditionally, through-the-scope (TTS) clipping devices consist of 2 main components: metallic double pronged clips and delivery/deployment catheter-handle assembly. TTS clips are the most used devices for both hemostasis and defect closure given the familiarity and ease of use. However, larger defects or those in a difficult position within the GI tract can be difficult to close using conventional TTS clips alone, given the inherent restrictions in clip opening width and inability to approximate large gaps firmly and securely. Incomplete closure can have serious consequences, including delayed bleeding and need for additional interventions including surgery for treatment of acute perforations.

The Dual Action Tissue (DAT) clip is a novel, Federal Drug and Administration (FDA) approved commercially available 3-arm TTS clip designed for endoscopic closure of large defects. Compared to conventional TTS clips, the DAT clip has an additional center post or fixed column in the middle position. The two arms of the DAT clip operate independent of each other, with an overall maximum opening width angle of 60 degrees. Opening and closing of each arm is controlled by two color-coded handles, which facilitates distinguishment of the clip arms during operation. The arm on one side of the DAT clip is opened to clamp the edge of a defect. The clamped mucosa can then be pulled close to the other side of the defect. The second arm of the DAT is then opened to clamp the opposite edge. Once both edges of the defect are secured by the arms of the DAT clip, the clip can then be deployed by firmly pressing and releasing both handles simultaneously.

Experimental studies using the DAT clip have confirmed its safety and efficacy and shown it to be easy to operate, safe and effective for defect closure. Our initial experience in 6 cases (unpublished data) supports its safety and its utility as an additional endoscopic tool in our armamentarium for challenging tissue approximation. However, more data is needed to evaluate the performance and the role of the DAT clip. The purpose of this study is to prospectively evaluate our experience with the DAT clip as part of routine medical care.

Inclusion Criteria:

• Age 18 years or older.
• Patients scheduled to undergo endoscopic procedures as part of their routine care in which endoscopic clip closure is clinically indicated:

Treatment of bleeding Treatment of perforation and/or fistulas Tissue approximation for mucosal gaps associated with endoscopic resection (e.g., endoscopic mucosal resection, endoscopic submucosal dissection) or third space endoscopy (e.g., peroral endoscopic myotomy in the gastrointestinal tract)

Exclusion Criteria:

• Any contraindications to performing endoscopy.
• Participants in another research protocol that could interfere or influence the outcomes measures of the present study.

Adult patients scheduled to undergo endoscopic procedures at participating centers as medically indicated will be considered for the study.