This disclosure is related to devices and related methods for isolating atreatment region in a human body from fluid pressure. In various embodimentsan implantable device for isolating a treatment region in a human body fromfluidpressure comprises a first elongated segment, and a second elongated segment,and one or more branch segments in fluid communication with one of the firstelongated segment and the second elongated segment. The elongatedsegments have a combined cross section that is substantially conformable to anintraluminal cross section of a body lumen into which they are implanted. Amethod of installing an implantable medical device into the body of a patientcomprises deploying a first elongated segment, deploying a second elongatedsegment, and deploying one or more branch segments in a target region of avasculature.
