Apparatus and method for deploying an implantable device within the body

A method of implanting a device having a main lumen and at least one side-branch lumen extending therefrom to a target location within a vessel or tubular structure within the body having a main vessel and at least one side branch vessel in fluid communication with the main vessel, the method comprising:

• advancing the device through a vasculature using a catheter, where the device is in a stretched or tensioned state such that a diameter of the device is reduced;
• partially deploying the device from the first end of the catheter at the target location to position the main lumen of the device in the main vessel, wherein during partial deployment the device is selectively tensioned while maintained in the stretched or tensioned state, such that selectively tensioning the device can reposition the device by expanding and reducing the diameter of the device during delivery so that it can be repositioned, subsequently withdrawing the catheter relative to the device to expose the at least one side-branch lumen;
• guiding the respective side-branch lumen into at least one side branch vessel using a second catheter while the side-branch lumen is in the stretched or tensioned state;
• and
• fully deploying the device from the first end of the catheter by releasing the device from the stretched or tensioned state so that the device expands against the main branch vessel and side branch vessel to form a seal with the wall of the vessel.