Abstract: A catheter for applying a medium into the middle ear, includes a shaft having a distal and a proximal end, an inflatable first balloon, the interior of the first balloon being in communication with a first inflation lumen, an inflatable second balloon which is arranged distally in relation to the first balloon, the interior of the second balloon being in communication with a second inflation lumen, an application lumen having an inlet opening, an outlet opening and a center section that extends from the inlet opening to the outlet opening, the inlet opening being arranged outside of the shaft, the center section extending at least partially through the shaft and the outlet opening being arranged distally in relation to the proximal end of the second balloon, as well as a vent lumen having an inlet opening, an outlet opening and a center section that extends from the inlet opening to the outlet opening, the inlet opening being arranged distally in relation to the proximal end of the second balloon, the center