Cannulas are provided for delivering therapeutic material to a treatment
site. The cannula includes a cannula body with a plurality of openings at
the distal end, including a longitudinal opening and a plurality of
transverse openings that are axially spaced from each other. The cannula
also includes a plunger that is configured to be slidably disposed within
the cannula lumen. When the plunger is proximally displaced in the cannula
lumen, the plunger seals the distal end and deflects the therapeutic
material out the transverse openings. As the plunger is proximally
displaced within the lumen, the therapeutic material is forced to perfuse
out transverse openings located proximal of the plunger position. In one
embodiment, the plunger includes an additional pliable sealable member. In
another embodiment, the distal end of the cannula body may be implanted by
separating the distal end from the cannula body.
