Venocclusion Device

Abstract

A device designed to be implanted in a blood vessel such as the inferior vena cava, as a substitute for a tying or clamping operation on such vessel, the device being inserted in deflated condition through a simple incision, moved to the desired location, inflated to engage securely the wall of the vessel and then detached from the inserting means. The device comprises a generally cylindrical core body containing one or more one-way valves and having around its outer surface an inflatable balloon, the device being initially mounted on and inserted by an elongated catheter traversed by a needle through which inflation fluid is fed to the balloon; withdrawal of the needle after inflation permits the valve or valves to close and simultaneously separates the device from the catheter.

Description

The problem of migration of clots from veins in the legs toward the heart has been met heretofore by a dangerous major operation in which the inferior vena cava is tied, causing blood to return to the heart by way of collateral circulation. The background of the present invention is clearly set forth in Mobin-Uddin U. S. Pat. No. 3,540,431, wherein an umbrella-like device is proposed, to serve as a permanently implanted filter. That patent also suggests that the "canopy" part of the umbrella may be impervious, for complete occlusion, and it is known that the filter commonly becomes clogged sooner or later so that the passageway is completely blocked, either intentionally or otherwise. Other forms of occlusion devices are shown in Hunter and Sessions application Ser. No. 878,813, filed Nov. 21, 1969, (and continuation application Ser. No. 232,323, filed Feb. 23, 1972) under which applicant's assignee is licensed, and the present invention being specifically an improvement on the Hunter and Sessions devices.

Objects of the present invention are the provision of an occlusion device with a balloon assembly in which the balloon material is practically impervious to the inflating fluid, in which a spring-loaded mechanical valve is in series with a plug of self-sealing material under compression, and in which the balloon assembly is detachably secured to the end of the inserting catheter only by means of the inflating needle. Additionally, the catheter is provided with a passage, an inlet fitting and outlet holes for feeding radiopaque dye to a point in the vessel, as an aid in the precise location of the occlusion device.

A practical embodiment of the invention is shown in the drawings, wherein:

FIG. 1 represents a longitudinal axial section of the occlusion device, needle and distal end of the insertion catheter with valve open;

FIG. 2 represents a similar longitudinal axial section with the balloon inflated and valve closed;

FIG. 3 represents an elevation of the occlusion device and insertion catheter, with fittings, part of the length being indicated by a broken line;

FIG. 4 represents a detail elevation, on an enlarged scale, of the proximal end of the catheter and its fitting, parts being in section and parts being broken away.

Referring to the drawings, the occlusion device 10 is shown as comprising cylindrical body portion 11 having a tapered distal end 12 and a proximally open axial bore 13, the distal portion 14 of said bore having a smaller diameter than the proximal portion thereof and said portions being defined by an annular shoulder 15 forming a proximally facing seat.

A distally recessed annular retainer 16 rests against the shoulder 15 and an O-ring 17 is seated in the recess. Proximally of the retainer 16, the bore 13 is filled with a self-sealing rubber compound 18 held in the bore 13 by a tight fitting plug 19 having a small axial bore 20. A valve 21 having a beveled face 22 is slidable in the portion 14 of the bore, constituting a valve compartment, the valve being urged by a spring 23 under compression toward engagement with the O-ring 17. One or more radial holes 24 extend outward from the portion 14 at points near the proximal end of said portion.

The latex rubber balloon 25 is applied to the outer surface of the body 10, preferably, by first stretching the end 26 of a cylindrical rubber sleeve or sheath over the proximal end of said body, wrapping said end tightly with thread (Dacron) 27, reversing the sleeve to cover the thread, as shown, and securing the distal end 28 of the sleeve against the tapered distal end 12 of the body 10 by means of an internally tapered ring 29 which is held in place by a round-headed screw 30 threaded into the distal end of the body 10. The ring 29 and screw 30 are very precisely proportioned to hold the sleeve end 28 securely in sealing contact with the tapered end 12 of the body but without undue compression, and the diameters of said ring and screw are the same so that a comparatively smooth edge is formed at their juncture. In addition to the fastenings just described the balloon sleeve or sheath may be cemented to the body 10 at any desired areas in order to predetermine the size and shape of the balloon when inflated.

The insertion catheter 35 is an elongated plastic tube having a small bore 36, a simple adapter fitting 37 at its distal end and a multi-purpose fitting 38 at its proximal end. The fitting 37 has a plug portion 39 seated within the end of the catheter, a socket 40 (which may be slightly flaring) to receive the proximal end of the body portion 10 and a cylindrical or slightly tapering outer surface 41 which is flush, proximally, with the outer surface of the catheter and distally with the wrapped proximal end 26 of the rubber balloon 25.

The proximal fitting 38 is traversed by an axial bore 42 and has a plug portion 43 seated within the end of the catheter, a Luer lock 44 on a separate base 45 at its proximal end with valve 46 and a side-arm two-way Luer lock 47 with valve 48, communicating with the bore 36. An annular flange 49 extends radially outward from the bushing 50 which is threaded on the proximal end of the fitting 38.

The needle 31 has an outside diameter smaller than the bore 36 of the catheter, and a lumen extending from the proximal end Luer lock fitting 44 to a lateral opening 52 spaced from the distal tip 53, the needle being securely fixed to the base 45. The length of the needle is such that, when the base 45 is engaged against the fitting 38 and bushing 50, the sharply pointed tip end 53 will extend through and beyond the self-sealing material 18 to a position within the valve bore 14 where it holds the valve 21 wide open (FIG. 1), with the opening 52 in the bore 14 more or less opposite the opening or openings 24. The base 45 is held non-rotatably in its set position by means of pins 55 mounted in the base and extending into holes in the fitting 38.

With the parts assembled in the position of FIG. 1, the occlusion device 10 is introduced into a selected vessel and advanced to the desired location, such as the inferior vena cava, the position and progress of the device being monitored radioscopically, with or without the injection of dye and/or heparin saline through the side-arm 47, lumen 36 and radial passages 56 near the distal end of the catheter 35. During introduction of the occlusion device the body 10 is held firmly in the socket 40 on the end of the catheter by the engagement of the needle 31 in the compressed mass of self-sealing material 18, this engagement being secure enough to permit the occlusion device to be adjusted in either direction to its optimum position. Upon reaching that position, inflation of the balloon 25 is effected by injecting an inflation fluid from a syringe (not shown) through the luer lock fitting 44, the lumen of the needle and the opening 52.

The fluid acts through the opening 24 to inflate the balloon 25 to a diameter sufficient to engage securely the adjacent wall of the vessel to be occluded, the size of said vessel being generally both known and observable. When satisfactory engagement has been effected, inflation is stopped, the base 45 is disengaged from the fitting 38 and the needle is carefully withdrawn, as by screwing in a proximal direction the bushing 50.

As the needle is withdrawn from the open position of FIG. 1 to the closed position of FIG. 2 the valve 21 is moved proximally by the spring 23 until the surface 22 comes to a rest on the O-ring 17, creating a tight seal as the O-ring is compressed into the recess of retainer 16. Further retraction of the needle eventually frees its tip portion from the material 18, the hole made by original insertion of the needle closing tightly in the wake of the needle point to create a second seal, preventing leakage of the inflation fluid in the event that any is able to pass the O-ring. The cylindrical body of the valve 21 may be so proportioned that its surface will, in the closed position, seal off the opening 24, as an additional precaution against leakage.

For optimum results, the balloon has to be scientifically compounded to reduce the effect of osmolarity imbalance, prevent premature deflation, and transfer of liquid and salts from inside the balloon to the surrounding tissue. The balloon must be of a sufficient modulus to prevent premature rupture while under tension.

The balloon shape is substantially spherical when unrestricted, but becomes somewhat elongated when inflated against the wall of the inferior vena cava. Its proportions can be designed for use in occluding vessels from 4F through 22F.

It will be understood that various changes may be made in the form, construction and arrangement of the several parts without departing from the spirit and scope of the invention and hence I do not intend to be limited to the details shown or described herein except as the same are included in the claims or may be required by disclosures of the prior art.

Claims

What I claim is:

1. A blood vessel occluding device comprising, a rigid cylindrical body having distal and proximal ends and an axial bore, means closing the distal end of said bore, a valve seat spaced from said closing means, to define a valve compartment between said closing means and said seat, a valve movable in said compartment toward and away from said seat, a passage extending outward from said compartment through the body wall, resilient means urging said valve toward engagement with said seat, a mass of self-sealing material substantially filling said bore proximally of said valve seat, means at the proximal end of said body for retaining said mass in said bore, and a sheath of stretchable fluid-impervious material sealed to said body distally and proximally of said passage and adapted to be inflated to form a balloon around said body.

2. A blood vessel occluding device according to claim 1 which includes a ring engaging the distal end portion of the sheath to hold it in sealing contact with the body surface.

3. A blood vessel occluding device according to claim 2 which includes a smoothly rounded distal tip element adapted to hold the ring in sheath engaging position.

4. A blood vessel occluding device according to claim 1 wherein the valve seat and the mass retaining means are traversed axially by openings to permit passage of an inflating needle.

5. In combination, the occluding device as claimed in claim 1 and a positioning device comprising an elongated flexible catheter, a fitting on the distal end of the catheter having a socket adapted to receive the proximal end of the body and an axial opening, an elongated needle having a bore and a distal end, the bore terminating distally in an opening adjacent said distal end, and means for moving said needle axially relative to said catheter, the occluding device being associated with the positioning device with the proximal end of the body seated in the socket and the needle passing through the mass of material and projecting distally therefrom sufficiently to hold the valve off its seat and provide communication between the distal opening in the needle and the outwardly extending passage.

6. The combination according to claim 5 wherein the outer surface of the fitting forms a smooth continuation of the outer surface of the catheter at the distal end of the latter.

7. The combination according to claim 5 wherein the outer surface of the fitting forms a smooth continuation of the outer surface of the balloon sheath at the proximal end of the latter.

8. The combination according to claim 5 wherein the needle moving means includes a fitting on the proximal end of the catheter and a separate base element, the needle having its proximal end connected to said base element and passing through said proximal catheter fitting, and said base element being adapted to rest against said latter fitting.

9. The combination according to claim 8 which includes a flanged bushing threaded to the proximal catheter fitting and adapted to be positioned to determine the axial position of the separate base element relative to said latter fitting.

10. The combination according to claim 8 which includes means preventing rotation of said base element relative to said proximal catheter fitting.