Abstract: In some examples, a catheter apparatus, configured to cut through a vessel wall, includes an elongate body including a distal end. A cutting device, configured to selectively cut a hole in the vessel wall, is disposed at the distal end of the elongate body. The cutting device includes a substantially ring-shaped cutting portion including a first dimension and a second dimension, wherein the first dimension is greater than the second dimension. The gripping device, disposed at the distal end of the elongate body, is configured to grip the vessel wall to maintain the cutting device proximate the vessel wall during cutting of the hole in the vessel wall. The gripping device is further configured to retain a portion of the vessel wall removed during cutting of the vessel wall. In some examples, a method includes using a catheter apparatus to cut through a vessel wall.