Apparatus for injecting fluids into the walls of blood vessels, body cavities, and the like

Apparatus for injecting fluids into the walls of blood vessels, body cavities, and the like, includes a plurality of laterally flexible needles disposed in a catheter for exit either out the distal end of the catheter or the catheter or through corresponding side openings in the catheter. In the latter case, the terminal ends of the needles would be curved laterally, with each terminal end being positioned in a respective side opening so that when the needles were moved forwardly in the catheter, the terminal ends of the needles would move laterally out the respective openings to pierce a vessel or cavity wall adjacent to which the catheter was positioned. Hilts positioned near the terminal ends of the needles serve to control the depth of penetration of the needles.

BACKGROUND OF THE INVENTION
 1. Field of the Invention
 This invention relates to invasive medical devices for injecting
 medications and therapeutic agents into the walls of blood vessels, body
 cavities, ducts, organs, tumors and the like. More particularly, the
 present invention relates to devices for concentrating the delivery of
 such medications and agents to the walls of the blood vessels, cavities
 and ducts.
 2. State of the Art
 Various vascular diseases involving vessel walls, such as arterial
 sclerosis, occlusive lesions, aneurysm or other weakening of the vessel
 wall, etc., may benefit from the application of medications directly to
 the affected area of the vessel wall. This may be done systemically by
 injecting medication into the vessel and then allowing the blood to carry
 the medication to the affected area. The problem with this approach is
 that high dosages of medication are required to ensure that some small
 portion reaches the affected area, and the high dosage may be harmful to
 other organs or body parts. Also, systemic application is generally not
 effective and quite expensive.
 Another approach to treating diseases of vessel walls is to place a block
 before and after the affected area and then inject medications into that
 portion of the vessel between the two blocks. The problem with this
 approach is that blood flow is stopped for a certain amount of time and
 this, in itself, is dangerous; also, may not be able to stop the flow long
 enough for uptake of the medications.
 Another prior art approach is to thread a catheter through the blood vessel
 to the affected area and then either supply the medication through the
 catheter to the affected area or supply the medication through a needle
 which itself is threaded through the catheter, pierce the vessel wall with
 the needle, and then supply the medication (see U.S. Pat. No. 5,354,279).
 The problem with simply supplying the medication via the catheter is that
 much of the medication is carried away in the blood and may adversely
 affect other organs.
 An additional prior art approach to supplying medication to a vessel wall
 involves the use of an inflatable sleeve positioned adjacent the affected
 area, where the sleeve includes an annular cavity holding the medication.
 When the sleeve is inflated to expand outwardly, the medication held in
 the cavity is placed into contact with the vessel walls and released
 thereinto. The problem with this approach is that the blood vessel again
 is blocked for a time and thus a gradual therapeutic regimen is not
 possible.
 Other approaches to delivering medication to vessel walls are disclosed in
 U.S. Pat. Nos. 5,681,281, 5,364,356, and 5,112,305.
 OBJECTS AND SUMMARY OF THE INVENTION
 It is therefore an object of the present invention to provide a device for
 injecting medication, therapeutic agents, and the like efficiently and
 effectively into a blood vessel wall, body cavity wall, duct wall, etc.
 It is also an object of the invention to provide such a device which is
 non-occlusive and substantially non-inhibiting of blood flow.
 It is a further object of the invention to provide such a device which may
 be easily deployed through the vascular system and other body cavities or
 ducts to desired target locations for delivering the medication,
 therapeutic agents, and the like.
 It is an additional object of the invention to provide such a device, in
 accordance with one aspect thereof, in which the vessel or cavity wall may
 be penetrated and the degree of penetration may be controlled.
 The above and other objects are realized in one illustrative embodiment of
 the invention which includes a plurality of laterally flexible needles
 disposed in a catheter for exit either out the distal end of the catheter
 or through corresponding side openings in the catheter. In the latter
 case, the terminal ends of the needles would be curved laterally, with
 each terminal end being positioned in a respective side opening so that
 when the needles were moved forwardly in the catheter, the terminal ends
 of the needles would move laterally out of the respective openings to
 pierce a vessel, cavity or duct wall adjacent to which the catheter was
 positioned. In the former case, the terminal ends of the needles would be
 curved to extend radially so that upon exit from the distal end of the
 catheter, the terminal ends of the needles would move radially to contact
 and pierce a vessel or cavity wall.
 Upon piercing the vessel or cavity wall, medication would be supplied to
 the needles for delivery to the vessel, cavity or duct wall. Hilts
 positioned near the terminal ends of the needles serve to control the
 depth of penetration of the needles.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
 Referring to FIG. 1, there is shown a side, fragmented, partially
 cross-sectional view of one embodiment of a device for delivering
 medication to the walls of a vessel, duct or body cavity. Here, the distal
 end of a catheter 10 is shown disposed within a blood vessel 14. Disposed
 in the catheter 10 are a plurality of tiny hollow needles 18 whose
 terminal ends are preshaped to curve radially outwardly when unconstrained
 by the catheter 10. Thus, when pushed out of the distal end of the
 catheter 10, the terminal ends of the needles 18 curve radially toward the
 walls of the blood vessel 14 to pierce the walls. Medication may then be
 supplied through the needles 18 into the vessel walls to treat the vessel
 wall in a circumferential manner.
 Hilts 22 are provided near the terminal ends of the needles 18 to prevent
 piercing the walls of the blood vessel 14 beyond a certain distance. In
 particular, the needles penetrate the vessel wall until the hilt makes
 contact therewith to stop further penetration. The hilts 22 may be
 selectively positioned at the terminal ends of the needles 18 to
 effectively control the depth of penetration of the needles.
 Advantageously, the needles may be made of stainless steel, and the
 catheter of various plastics.
 A radiopaque marker 26 may be provided on the distal end of the catheter 10
 to allow tracking the position of the end of the catheter in the body (by
 radioscopy), and thus, the position or location at which the needles exit
 the catheter.
 FIG. 2 is an alternative embodiment of a needle injection device made in
 accordance with the present invention. Here, a catheter 30 is shown
 disposed within a blood vessel 34. The catheter 30 includes a plurality of
 openings 36 generally arrayed in a line on one side of the catheter, and
 in which are positioned the terminal ends of hollow needles 38. The
 needles would be placed in the catheter 30 with their terminal ends
 positioned in the openings 36, and then the catheter would be threaded
 into the blood vessel 34 to the target location.
 The terminal ends of the needles 38 are preformed with a curve so that when
 the catheter 30 is moved adjacent to the target location, the needles may
 be moved forwardly in the catheter, causing the needles to exit the
 openings 36 and move laterally into contact and pierce the walls of the
 blood vessel 34. The terminal ends of the needles 38 also include hilts 42
 to prevent the needles 38 from piercing the vessel wall greater than a
 certain distance.
 To facilitate rotational positioning of the catheter 30 (so that the
 openings 36 are positioned adjacent the area to be treated), the catheter
 may be constructed with a proximal section formed to be torsionally stiff
 (e.g. stainless steel) and a distal section formed to be torsionally stiff
 yet laterally flexible (e.g. nickel-titanium alloy including cuts to
 predetermine the flexibility). See co-pending U.S. patent application,
 Ser. No. 08/653,289, filed May 24, 1996. Radiopaque markers 46 could also
 be provided as described for the FIG. 1 embodiment. After the needles 98
 are in place in the vessel wall, medication would be supplied to the
 needles for injection into the vessel wall as desired.
 FIG. 3 shows a fragmented, side, cross-sectional view of another embodiment
 of the invention, which includes a primary catheter section 52 on the
 distal end of which is a secondary catheter section 56. A single hollow
 needle or tube 60 is disposed in the primary catheter section 52, and
 includes a manifold 64 formed on the distal end of the tube. Extending
 forwardly from the manifold 64 are a plurality of needles 68 and 72,
 formed to curve radially outwardly at their terminal ends when
 unconstrained. Thus, when the tube is withdrawn so that the manifold 64
 abuts against the end of the primary catheter section 52, the ends of the
 needles 68 and 72 are withdrawn into the secondary catheter section 56.
 When the tube 60 is moved forwardly, the ends of the needles 68 and 72
 emerge from the secondary catheter section 56 and curve radially outwardly
 to pierce the walls of a blood vessel, duct or body cavity into which the
 device has been inserted. Hilts 76 disposed near the pointed ends of the
 needles 68 and 72, prevent penetration of the needles beyond a certain
 distance, as described earlier.
 FIG. 4 is a side, elevational view of another embodiment of the invention
 somewhat similar to the embodiment of FIG. 1. In FIG. 4, a distal end of a
 catheter 80 is shown, with a plurality of small hollow needles 84 disposed
 in the catheter. Also disposed in the catheter 80 is a deflection guide 88
 which is enlarged on its distal end so that when the needles 84 are pushed
 forwardly in the catheter 80, the ends of the needles are deflected
 radially outwardly as shown to penetrate the walls of a blood vessel, duct
 or body cavity. Hilts 92 are formed near the tips of the needles to limit
 the depth of penetration of the needles in the body cavity wall.
 Of course, once the needles have been deployed to penetrate the body cavity
 walls, medication would be supplied through the needles and into the walls
 for the desired treatment.
 FIG. 5 is a perspective, fragmented view of a further embodiment of the
 invention, and shows a distal end of a catheter 100 in which are disposed
 a plurality of small needles 104. Hilts 108 are disposed near the ends of
 the needles 104 as previously described. Formed in a side wall of the
 catheter 100 are a plurality of pockets or recesses 112 into which the
 ends of the needles 104, along with the respective hilts 108 can nest when
 the needles are withdrawn. When the needles 104 are pushed forwardly, the
 ends are preformed to curve and move radially outwardly to penetrate the
 wall of a blood vessel, duct or body cavity, as before described. Note
 that the pockets 112 and needles 104 are arranged generally in a line,
 similar to the configuration of FIG. 2.
 FIG. 6 is a fragmented, perspective view of still another embodiment of the
 invention in which a plurality of needles 120 are carried by a catheter
 124, with some of the needles 120 positioned radially about the catheter
 124 to nest in respective pockets or recesses 128, and with other needles
 positioned to extend out the distal end of the catheter through openings
 132. The openings 132 allow for the needles 120 to project therethrough,
 but are too small for hilts 136 formed near the ends of the needles to
 slide through the openings. Thus, when the needles 120 which project out
 the end of the catheter 124 are withdrawn, the hilts 136 serve as a stop
 for withdrawing the needles too far. Similarly, the needles disposed
 radially about the side of the catheter 124 and which nest in pockets 128,
 also are limited as to how far they may be withdrawn by the hilts 136
 contacting rear walls 140 formed in the recesses 128. The needles 120
 project through openings 144 in the rear walls 140 and can slide readily
 therein, but the hilts 136 are too large to move through the openings.
 The needles 120 are preformed to curve radially outwardly when the needles
 are moved forwardly in the catheter 124 so that the needles may penetrate
 walls of blood vessels, ducts, or body cavities into which the catheter
 has been threaded.
 FIGS. 7A and 7B show respectively a perspective view and a fragmented, side
 cross-sectional view of a balloon actuated needle injection system made in
 accordance with the present invention. The system includes an elongate
 balloon 150 which is initially disposed in a catheter 154 in a deflated
 condition, as indicated in the end, cross-sectional view at 158.
 Disposed on opposite sides of the balloon 150 are a pair of hollow rails
 162 in which are disposed a plurality of laterally extending hollow
 needles 166 as best seen in FIG. 7B. The hollows in the needles 166 are in
 communication with the respective hollows in the rails 162 so that
 medication supplied to the hollow of the rails will flow through and out
 the needles. A pair of supply tubes 170 are coupled to respective ones of
 the hollow rails 162, again as best seen in FIG. 7B.
 A tube 174 is coupled to a rear end of the balloon 150 to supply air or
 other gas to inflate the balloon and thereby force the rails laterally
 outwardly to cause the needles 166 to pierce adjacent walls of a blood
 vessel, duct or other body cavity. An end view of an inflated balloon is
 shown at 178.
 The tubes 170 coupled to the hollow rails 162 extend in the catheter 154 on
 either side of the tube 174 which is coupled to the rear end of the
 balloon 150. Advantageously, the tubes 174 are longitudinally stiff to
 allow pushing the rails 162 forwardly in the catheter 154 to carry along
 the balloon 150 until the balloon and rails reach the desired target
 location. The device is inserted with the needle rails 162 withdrawn up
 inside a catheter to protect the vessel walls from abrasion.
 The rails 162 may be affixed to the balloon 150 for support, as shown in
 FIGS. 7A and 7B. Alternatively, they may be supported by one or more
 stent-like biasing structures 180, shown in FIG. 7C. As is well known to
 those skilled in the art, a stent is a device used to provide support for
 tubular structures or passageways such as blood vessels, etc. Like a
 stent, the biasing structures 180 are spring-like coils which surround the
 balloon 150 to force the rails 162 outward when not constrained within the
 catheter 154. Unlike stents, however, the biasing structures 180 have
 elastic memory which causes them to return to a small size for retraction
 through the catheter.
 FIG. 8A provides a cross-sectional view of another embodiment of the
 present invention, and FIG. 8B is a side, cross-sectional view. Shown is a
 wall 200 of a blood vessel (or other body cavity). A catheter 204 is
 disposed in the blood vessel, and includes three openings 208
 circumferentially spaced apart about the catheter as shown. Disposed in
 the lumen of the catheter is a supply tube 212 (FIG. 8B) having three
 branching needles 216 at its terminal or distal end. The needles 216
 initially branch forwardly and then are curved radially outwardly so that
 the sharp ends of each of the needles resides in a respective one of the
 openings 208 of the catheter 204.
 In use, after the catheter 204, with supply tube 212, is in position in the
 blood vessel, the supply tube 212 is rotated as indicated in FIGS. 8A and
 8B and this causes the curved ends of the needles 216 to move generally
 radially outwardly through the openings 208 to pierce the vessel wall 200.
 Medication may then be supplied via the supply tube 212 and through the
 needles 216, into the vessel wall 200. In this manner, after positioning
 the catheter and supply tube at a target location, a simple rotational
 movement causes extension of the needles 216 to pierce the vessel wall to
 allow application of medication.
 It is to be understood that the above-described arrangements are only
 illustrative of the application of the principles of the present
 invention. Numerous modifications and alternative arrangements may be
 devised by those skilled in the art without departing from the spirit and
 scope of the present invention and the appended claims are intended to
 cover such modifications and arrangements.