Disclosed are implantable medical devices (500, 1200, 1300) for connecting tissue layers, such as for connecting a gallbladder and a portion of a gastrointestinal tract to create an anastomosis, include a tubular structure having a plurality of apposition portions (502, 1202,1302 504,1204,1304), a central portion (506), and a covering material (512). The devices can be used by endoscopic deployment, and the devices may include self-expanding frameworks that facilitate a secure connection between the tissue structures.