Injection devices and systems and methods for using them

A device for injecting one or more agents into tissue within a patient's body, comprising:

• a substantially radially fixed tubular member comprising a proximal end and a distal end sized for introduction into a patient's body, at least a distal portion of the tubular member being sufficiently flexible to allow introduction into tortuous anatomy within a patient's body, the tubular member comprising a coil including windings extending between the proximal and distal ends and a tensile element coupled to the proximal and distal ends;
• a flexible, fluid-tight member disposed within an interior region of the tubular member and extending between the proximal and distal ends, the fluid-tight member fixed at the distal end of the tubular member and free-floating within the interior region at least partially between the proximal and distal ends of the tubular member, the fluid-tight member defining a lumen extending between the proximal and distal ends of the tubular member, the fluid-tight member being expandable within the interior of the tubular member when exposed to internal fluid pressure with the tubular member limiting expansion of the fluid-tight member;
• and
• a needle tip fixed to and extending from a distal end of the tubular member and having a cross-section smaller than the distal end, the needle tip comprising a passage communicating between the lumen and one or more outlets in the needle tip, the passage having a cross-section smaller than the lumen.

A method for delivering one or more agents into tissue, comprising:

• providing an injection device comprising:
• a substantially radially fixed tubular member including a proximal end, a distal end, a flexible, fluid-tight member disposed within an interior region of the tubular member and extending between the proximal and distal ends, the fluid-tight member defining a primary lumen extending between the proximal and distal ends, and a secondary lumen extending between the proximal and distal ends, the fluid-tight member being expandable within the interior of the tubular member when exposed to internal fluid pressure with the tubular member limiting expansion of the fluid-tight member;
• a distal stop;
• and
• a needle tip fixed to and extending from the distal stop including a passage communicating with both the primary lumen and the secondary lumen and an outlet of the needle tip, the needle tip having a cross-section smaller than the distal end and comprising a passage communicating between the primary lumen and one or more outlets in the needle tip, the passage having a cross-section smaller than the lumen, the secondary lumen also communicating with the passage such that fluids may be selectively delivered through the passage from either of the primary lumen and the secondary lumen;
• introducing the distal end of the elongate member into a body lumen adjacent a target injection site;
• delivering contrast through the secondary lumen and the passage out the outlet into the target injection site;
• using external imaging to confirm that the needle tip is positioned at the target injection site;
• delivering material through the primary lumen and the passage out the outlet into the target injection site;
• and
• delivering fluid through the secondary lumen to clear residual material from the passage.

A device for injecting one or more agents into tissue within a patient's body, comprising:

• a substantially radially fixed tubular member comprising a proximal end and a distal end sized for introduction into a patient's body, at least a distal portion of the tubular member being sufficiently flexible to allow introduction into tortuous anatomy within a patient's body;
• a flexible, fluid-tight member disposed within an interior region of the tubular member and extending between the proximal and distal ends, the fluid-tight member defining a lumen extending between the proximal and distal ends, the fluid-tight member being expandable within the interior of the tubular member when exposed to internal fluid pressure with the tubular member limiting expansion of the fluid-tight member;
• and
• a needle tip fixed to and extending from a distal end of the tubular member and having a cross-section smaller than the distal end, the needle tip comprising a passage communicating between the lumen and one or more outlets in the needle tip, the passage having a cross-section smaller than the lumen,
• wherein the lumen defined by the fluid-tight member is a primary lumen, the device further comprising a secondary lumen extending between the proximal and distal ends and also communicating with the passage such that fluids may be selectively delivered through the passage from either of the primary lumen and the secondary lumen.