A system for tissue approximation and fixation is described herein. The
devices are advanced in a minimally invasive manner within a patient's
body to create one or several divisions or plications within a hollow
body organ. The system comprises a tissue acquisition and folding device
and a tissue stapling or fixation device, each of which is used together
as a system. The acquisition device is used to approximate tissue regions
from within the hollow body organ and the stapling device is advanced
through a main lumen defined through the acquisition device and is used
to affix the approximated tissue. The stapling device is keyed to
maintain its rotational orientation relative to the acquisition device as
well as to provide the user positional information of the stapling
device. The acquisition device is also configured to provide lateral
stability to the stapling device prior to the stapling device being
clamped onto tissue.