Abstract: A medical catheter includes a multi-lumen tube including a first lumen and a second lumen; an extension tube fixed to an end surface in a longitudinal direction of the multi-lumen tube, extending from the end surface along the longitudinal direction, and including a third lumen communicating with the first lumen; and an outer wall portion extending from the multi-lumen tube along the extension tube and configured to cover a part of an outer surface of the extension tube, the outer wall portion including a pipeline formed to communicate with the second lumen and having a part of the outer surface in an inner surface of the pipeline.

Abstract: According to one aspect, a balloon-equipped treatment tool for an endoscope includes a balloon, and a sheath connected to a proximal end side of the balloon and configured to introduce fluid to the balloon. The balloon includes a body portion having a first wall thickness, a cylindrical tail portion arranged on a proximal end side of the body portion and connected to the sheath, a cone portion located between the body portion and the tail portion, and a thick portion forming a second wall thickness larger than the first wall thickness. The thick portion whose distal end is arranged in the cone portion and whose proximal end is arranged in the tail portion.