Medical device for ultrasound-assisted drug delivery

A system for treating a vascular region, the system comprising:

• an elongate catheter shaft having a distal end region;
• wherein a central lumen is formed in the elongate catheter shaft;
• an ultrasound treatment core disposed within the central lumen, the ultrasound treatment core including a plurality of axially-spaced ultrasound transducers;
• wherein the catheter shaft includes a plurality of shielded delivery lumens disposed adjacent to the central lumen, the plurality of shielded delivery lumens being configured to deliver microbubbles and/or fluid to a target region;
• and
• wherein at least a portion of each of the shielded delivery lumens is configured to protect microbubbles and/or fluid disposed within the shielded delivery lumens from the plurality of axially-spaced ultrasound transducers.

A method for delivering a drug to a vascular region, the method comprising:

• advancing a catheter system to a treatment site, the catheter system comprising:
• an elongate catheter shaft having a distal end region,
• wherein a central lumen is formed in the elongate catheter shaft,
• a treatment core disposed within the central lumen, the treatment core including a plurality of ultrasound transducers disposed adjacent to the distal end region of the elongate catheter shaft,
• wherein catheter shaft includes a fluid and delivery lumen configured to deliver microbubbles and/or fluid therein disposed adjacent to the central lumen, and
• wherein at least a portion of the fluid and delivery lumen is arranged relative to the central lumen so that microbubbles and/or fluid disposed within the fluid and delivery lumen are protected from ultrasound energy transmitted from the plurality of ultrasound transducers;
• advancing the treatment core through the central lumen so that the plurality of ultrasound transducers are disposed adjacent to the distal end region of the elongate catheter shaft;
• passing a therapeutic fluid through the fluid and delivery lumen;
• and
• activating at least some of the plurality of ultrasound transducers.