Engagement catheter devices, systems, and methods to use the same under suctional tissue engagement. A method of the present disclosure comprises the steps of engaging a targeted tissue under suction/vacuum using an engagement catheter, delivering a substance into or through the targeted tissue using a needle positioned within a first lumen of the engagement catheter, injecting a fluid within the first lumen of the engagement catheter to flush at least part of the first lumen with the fluid, and suctionally removing the injected fluid from within the first lumen of the engagement catheter.
