Gastrointestinal ImagingE2800. Imaging for Transmural Drainage of Pancreatitis-Related Collections With a Novel Stent
Holbert B, Whitworth P, Pawa R, Tappouni R. Wake Forest School of Medicine, Winston–Salem, NC
Address correspondence to B. Holbert (email@example.com)
Background Information: Pancreatitis-related collections, including pseudocyst (PS) and walled-off necrosis (WON), often fail transluminally placed plastic stenting and percutaneous drainage because of the difficulty draining nonliquefied necrotic material. Endoscopic transmural drainage is now increasingly used for treating symptomatic PS and WON to avoid invasive surgery. A new endoscopically placed lumen-apposing covered self-expanding metallic stent (LACSEMS) became available two years ago. This stent is designed with large diameter (> 10 mm) and flared ends for improved stabilization and more effective drainage and can accommodate an endoscope for future necrosectomies. The purpose of this exhibit is to review imaging features of PS and WON relevant to the employment of the LACSEMS and to discuss the role of CT and MRI in treatment planning and follow-up.
Educational Goals/Teaching Points: The goals of this exhibit are to first, review the CT and MRI findings of PS and WON according to the Revised Atlanta Definitions. Second, we will describe the technique, advantages, and concerns associated with the LACSEMS. Third, we will demonstrate how collection characteristics are used to select intervention and assist the gastroenterologist in planning stent insertion and necrosectomy. Fourth, we will recognize the utility of CT and MRI in subsequent resection of necrotic pancreatic debris through the stent.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques: Size, location, and nature of the symptomatic peripancreatic collection are critical in planning the procedure. The target must be a clearly defined PS or WON. The collection should have a diameter of 6 cm or greater, a location abutting stomach or small bowel, and a composition of at least 70% fluid. Imaging is crucial for detecting contraindications to stent placement, which include cystic neoplasm, pseudoaneurysm, duplication cyst, noninflammatory fluid collection, intervening gastric varices or other vessels within a 1-cm radius of the insertion site, and anatomy that prevents stent placement. Follow-up imaging can reveal a residual collection or complications.
Conclusion: Treatment of symptomatic pancreatic PS and WON is advancing rapidly with FDA approval of the LACSEMS. The benefits of this device are so substantial that gastroenterologists can reasonably expect that their radiology colleagues would be familiar with its use. The radiologist has a vital role in evaluating inflammatory peripancreatic collections, route planning for LACSEMS placement, and follow-up.