Luminal organ sizing devices and methods. In at least one embodiment of a method of the present disclosure, the method comprises the steps of introducing at least part of a first device into a luminal organ at an aperture or opening of the luminal organ, the first device having a balloon positioned thereon； inflating the balloon at the aperture or opening of the luminal organ until a point of apposition is achieved； and obtaining a first aperture or opening measurement based upon the point of apposition.
