Abstract: Devices, systems and methods for removal of a mitral valve clip and subsequent delivery of a mitral valve implantation in a mitral valve replacement procedure. A modular port accessory device having a distal connector configured to be compatible with corresponding connectors on an existing therapeutic device, wherein the port accessory can be selectively attached to a proximal end portion connector of a proximal end portion of a catheter assembly of an existing therapeutic device. The catheter assembly is introduced to a target site within the patient's anatomy, and remains in place throughout a multistep therapeutic procedure for use with other therapeutic devices, all while allowing hemostasis to be controlled during use ad interchange of multiple therapeutic devices.