Weeping balloon catheter

A balloon catheter comprising:

• a catheter shaft extending along a longitudinal axis and configured to carry a first fluid and a second fluid;
• a first balloon mounted on the catheter shaft and expandable with introduction of the first fluid therein, the first balloon having a first portion attached to the catheter shaft, a second portion disposed distal of the first portion and attached to the catheter shaft, and a middle region positioned from the first portion to the second portion of the first balloon, the first portion and the second portion of the first balloon joined to one another by the middle region, the first portion having an increasingly larger cross-sectional area along the longitudinal axis in a distal direction, the second portion having an increasingly smaller cross-sectional area along the longitudinal axis in the distal direction;
• and
• a second balloon mounted around at least a portion of the first balloon, the second balloon having a middle portion, a plurality of holes formed in the middle portion to define a perforated portion of the middle portion, the plurality of holes consisting of all of the holes through the second balloon;
• the first and second balloons in an expanded configuration structured and arranged to define an annular lumen therebetween, the annular lumen being in communication with the plurality of holes of the second balloon, the annular lumen configured to allow the second fluid to pass therethrough and out the holes,
• the annular lumen having a tapered working region extending longitudinally adjacent the perforated portion of the middle portion of the second balloon and a corresponding portion of the middle region of the first balloon, the annular lumen being defined by a length extending between a first end disposed longitudinally between the first portion and the second portion of the first balloon and at a most proximal hole of the plurality of holes of the second balloon, and a second end disposed distal of the first end and longitudinally between the first portion and the second portion of the first balloon and at a most distal hole of the plurality of holes of the second balloon, wherein the tapered working region has a cross-sectional area that decreases along the longitudinal axis in the distal direction along the length from the first end to the second end of the annular lumen.

A method of delivering a fluid to a treatment site within a body vessel, the method comprising:

• translating a balloon catheter to the treatment site within the body vessel, the balloon catheter comprising a first balloon coupled to a shaft and comprising a middle working region, a first portion contiguous with a first end of the middle working region, and a second portion positioned distal of the first portion and contiguous with a second end of the middle working region, the middle working region disposed from the first portion to the second portion, the first portion attached to the shaft and comprising an increasingly larger cross-sectional area along a longitudinal axis in a distal direction, the second portion attached to the shaft and comprising an increasingly smaller cross-sectional area along the longitudinal axis in the distal direction, a second balloon coupled to the shaft at least partially around the first balloon, the second balloon having a plurality of holes formed therein to define a perforated portion of the second balloon, the plurality of holes consisting of all of the holes through the second balloon, the first and second balloons structured and arranged in an expanded configuration to define an annular lumen therebetween, the annular lumen in communication with the plurality of holes and being disposed between the perforated portion of the second balloon and a corresponding portion of the first balloon, the annular lumen being defined by a length extending between a first end disposed at a most proximal hole of the plurality of holes of the second balloon and a second end disposed at a most distal hole of the plurality of holes of the second balloon, wherein said annular lumen has an increasingly smaller cross-sectional area along the longitudinal axis in the distal direction along the length from the first end to the second end of the annular lumen;
• expanding the first balloon to the expanded configuration;
• and
• introducing a fluid into the annular lumen between the first and second balloons to deliver the fluid through the plurality of holes of the second balloon to the treatment site of the body vessel.