US3730186A - Adjustable implantable artery-constricting device - Google Patents

Abstract

A device, completely implantable within the human body, for restricting the flow of blood through a major blood vessel, such as an artery, especially the pulmonary artery. An inflatable, flexible annulus, generally circular in shape but not a closed circle, has a non-distensible outer wall so that upon inflation all distention or expansion is inward. The device is placed around an artery or other blood vessel, and the ring may then be closed, as by suturing together preformed tabs attached to the annulus, or by suturing together the ends of an overlapping tape, for instance, to firmly hold the vessel. Upon inflation, inward distention of the inflatable annulus constricts the vessel, and flow of blood therethrough is accordingly restricted. Inflation and deflation are effected through a self-sealing hollow bulb and a non-distensible tube connecting the bulb to the interior of the inflatable annulus, pressure fluid being introduced into the bulb by a fine hypodermic needle. The device may be wholly contained within the patient''s body, and all surfaces thereof are of a substance, such as a medical elastomer, that is compatible with and resistant to the action of body fluids.

Description

1 United States Patent 1 Edmunds, Jr. et al.

[54] ADJUSTABLE IMPLANTABLE ARTERY-CONSTRICTING DEVICE [75] Inventors: Louis Henry Edmunds, Jr., Piedmont, Calif.; Silas A. Braley, Midland, Mich.

[73] Assignee: The Regents of The University of Calif., Berkeley, Calif.

[22] Filed: Mar. 5, 1971 [21] Appl.N0.: 121,406

[52] US. Cl. ..128/325, 128/327, 128/346, I 128/DIG. 25 [51] Int.Cl. ..A6lb 17/12 [58] Field ofSearch ..128/325, 326,327, 128/344, 346, DIG. 25

[56] References Cited UNITED STATES PATENTS 3,527,220 9/1970 Summers ..128/260 3,538,917 11/1970 Selker ..128/326 3,447,570 6/1969 Collinsm. ....l28/2l4RX 2,455,859 12/1948 Foley....... ....l28/346 7 3,176,690 4/1965 HDoubler ..128/348 OTHER PUBLICATIONS In Vivo Metric Systems Bulletin, March 1968, 2 shts. of Bulletin. Khouri et al., Jour. of Applied Physiology. Vol. 23 No.

V 11] 3,730,186 51 May 1, 1973 3, Sept. 1967, pp'. 395-397.

Primary Examiner-Dalton L. Truluck Attorney-Owen, Wickersham & Erickson 57 ABSTRACT A device, completely implantable within the human body, for restricting the flow of blood through a major blood vessel, such as an artery, especially the pulmonary artery. An inflatable, flexible annulus, generally circular in shape but not a closed circle, has a nondistensible outer wall so that upon inflation all distention or expansion is inward. The device is placed around an arteryor other blood vessel, and the ring may then be closed, as by suturing together preformed tabs attached to the annulus, or by suturing together the ends of an overlapping tape, for instance, to firmly hold the vessel. Upon inflation, inward distention of the inflatable annulus constricts the vessel, and flow of blood therethrough is accordingly restricted. Inflation and deflation are effected through a self-sealing hollow bulb and a non-distensible tube connecting the bulb to the interior of the inflatable annulus, pressure fluid being introduced into the bulb by a fine hypodermic needle. The device may be wholly contained within the patients body, and all surfaces thereof are of a substance, such as a medical elastomer, that is compatible with and resistant to the action of body fluids.

6 Claims, 5 Drawing Figures Patented May 1, 1973 I 3,730,186

INVENTORS LOUIS HENRY EDMUNDS, JR. SI L AS A. BRALEY ATTORNEYS ADJUSTABLE IMPLANTABLE ARTERY- CONSTRICTING DEVICE BACKGROUND OF THE INVENTION blood flow through the pulmonary artery. The device is suitable for prolonged use within the human body, i.e., for months or even years of such use.

The invention described herein was made in the performance of work under a research grant from the United States Public Health Service.

It has been recognized that approximately eight babies per thousand have congenital heart disease, and, of these, four have greater than normal pulmonary arterial blood flow. Such mechanical defects have led to attempts to develop a safe, reliable, adjustable device to effect arterial banding. Attempts previously have required that mechanical control be applied from outside the body, as by a screw device to manipulate a tape encircling a blood vessel, and heretofore no such device has been capable of being implanted in the body for permanent or at least long-term use.

The present invention provides a device for arterial banding and mechanical restriction of blood flow through an artery, or other major blood vessel. It is safe, is compatible with body fluids, and is controllable externally while being totally contained within the patients body. An advantage of the present invention is that the device is adjustable to conform to the size of the artery being banded and can be permanently emplaced, while yet periodic adjustments continue to be possible, as desired. Furthermore, the device is wholly implanted in the body and yet is later controllable without surgery. Further advantages are that adjustments can easily be made in the amount of inflation to accommodate for somatic growth, pulmonary pressure can be determined with the aid of this device, the band or annulus can be easily reached in order to close it upon emplacement and the connecting tube is short and non-twisting thus preventing interference in any desired flow of liquid.

SUMMARY OF THE INVENTION The present invention provides, in combination 1) an unclosed annulus or doughnut ring, capable of inward distention only, (2) a non-distensible bulb, (3) a non-distensible tube connecting the bulb to the annulus, and (4) means to control penetration by a later-inserted needle or the like and to protect the bulb from undesired punctures.

The annulus is shaped to form an unclosed circle, the circle being left open to enable insertion around an artery. The annulus is closed at both ends and has a distensible inner wall and a non-distensible or substantially non-distensible outer wall. The small non-distensible tube is affixed to the outer wall of the annulus at any convenient point and provides a conduit in open communication with the interior of the annulus through a suitable aperture in the outer wall of the latter. At the end of the tube distant from the annulus is the bulb, which is used to pump fluid through the conduit and into the banding annulus, thereby inflating the annulus and distending the inner wall. The distending of the inner wall exerts pressure on the enclosed portion of the artery or other blood vessel and completely or partially restricts the flow of blood therethrough.

The purposes of having a non-distensible outer wall of the annulus are (1) that the effect of inflation of the annulus be directed substantially entirely inwardly toward the enclosed artery, and (2) that any pressure on the surrounding body structure be avoided or minimized. The desired restraint on the outer wall can be effected in any desired manner, one advantageous means being to affix thereto a reinforcing layer of Teflon (tetrafluoroethylene) tape.

The banding annulus can be made in several sizes to accommodate different situations or needs. For instance, annu li can be supplied in various internal diameters of from about 1.0 cm. to 3.0 cm., e.g., in steps of 0.5 cm. of intervals, the diameters being measured when the annuli are uninflated.

The tube that connects the interior of the annulus to the interior of the bulb is not distensible and is suitably made of Dacron or possibly of hard, non-distensible medical elastomer, such as silicone rubber. The hollow bulb is also not distensible and can be made from the same or similar material. The volume of this bulb is suitably about from 3 to 6 ml. A sink or pan of suitable body-compatible metal, e.g., titanium, and having a base and a side wall conforming to the interior shape of the bulb is disposed within the base of the bulb and facilitates location of the injection chamber with a needle and prevents perforation of the floor or lower wall of the bulb itself. This will be further explained in the more detailed description below. In the insertion or emplacement of the device, the bulb is preferably disposed on the sternum just underneath the patients skin, where it can be readily located by palpation and inflated by means of a needle inserted through the skin.

The interior of the ring, tube and bulb are in open communication with each other and are self-sealing, and they must not leak. All surfaces of such a device to be wholly implanted in the body are made of a substance compatible with and resistant to the action of body fluids. Such a substance is suitably a medical elastomer such as silicone rubber, of varying degrees of hardness or cure to accommodate the need for distensible or non-distensible portions.

BRIEF DESCRIPTION OF THE DRAWINGS The invention and an advantageous mode of carrying it out are illustrated by the following description and by the annexed drawings, wherein:

FIG. 1 is a view in front elevation of an embodiment of an implantable pulmonary arterial band with the annulus partially inflated; the inner periphery is shown deflated in a broken line. Y I

FIG. 2 is a view in side elevation of the band of FIG. 1.

FIG. 3 is a view in section taken. on the line 3-3 of FIG. 1 of an inserted inflated annulus and its relationship to an enclosed artery.

FIG. 4 is a somewhat schematic view in side elevation of the device in place around the pulmonary artery of a patient.

FIG. 5 is a cross-sectional view of an embodiment of a non-distensible bulb of a device according to this invention showing the interior elements.

DETAILED DESCRIPTION OF THE INVENTION For purposes of illustration only, the invention is illustrated by the device shown in the accompanying drawings.

This device is a pulmonary arterial band or extravascular occluder and comprises an inflatable nonclosed ring or annulus of flexible material to enable its introduction around an artery to enclose it, a connectingtube 11 and abulb 12. Each of these components is made of or covered by material which is nontoxic and resistant to attack by body fluids, i.e., does not deteriorate within the body, because the entire device is to be implanted.

Theannulus 10 includes an inflatable or ballooninner portion 13 which is formed from a medical elastomer and is flexible and distensible. Preferably, it is made from or includes a selfsealing latex or elastomer. An advantageous type of such elastomer is the silicone rubber widely available in commerce in medical grades. Theannulus 10 is in the form of an incomplete or non-closed ring or circle, having two closed, sealed ends 14 and 15 forming an opening 16 therebetween. Theouter wall 17 of theannulus 10 is reinforced so that it is not distensible when internal fluid pressure is applied although it, too, remains flexible. This reinforcement can be accomplished in one embodiment as shown by incorporating or embedding afabric 18, such as nylon or Dacron mesh or cloth, within theouter portion 17 of thesilicone rubber annulus 10. The curvature of the casing orannulus 10 helps to direct the non-reinforced inflatable orballoon portion 13 inwardly as it is inflated and to prevent rolling or distortion ofsuch portion 13. An advantageous method of incorporating thefabric 18 in theannulus 10 is to form a coating piece or tire, of the required size and curvature, of such fabric molded into silicone rubber and to weld such tire to the outer surface of an inflatable tube of medical rubber.

The connectingtube 11 can be made from a harder, non-distensible silicone rubber, or of Dacron-reinforced silicone rubber, so that it remains of constant dimensions under the pressures to be, applied. It is relatively short and relatively thick-walled so as to be twistresistant and non-kinking. That is, the wall thereof may be from 0.062 to 0.065 inch thick and the tube is of such length as to extend in a substantially straight path, i.e., without curling upon itself, from adjacent the inner surface of the skin to the blood vessel to be treated. For example, the tube so extends from the sternum to the pulmonary artery area, in one embodiment, and is about four inches long. Thetube 11 connects with a suitable aperture in the reinforcedcasing portion 17 and debouches into the interior of theannulus 10, being sealed thereto to prevent leakage. At the end remote from theannulus 10, the tube connects with a suitable aperture in thebulb 12 similarly and is also sealed thereto. Advantageously, thetube 11 connects tangentially to the outer surface ofannulus 10, which provides for smoother flow of liquid therethrough and makes easier the placement of theannulus 10 relative to the artery.

Thebulb 12 can be formed of a flexible, nondistensible and self-sealing elastomer, such as a suitable reinforced or non-reinforced silicone rubber. It is adapted to being punctured and filled or emptied ofa pressureproviding fluid, such as 0.9 percent aqueous saline solution, by using a very fine hypodermic needle, e.g., a No. 22 or 25 needle. Upon withdrawal of the needle the bulb l2 seals itself. This result may be advantageously obtained by providing abulb 21 of a self-sealing elastomer. In one advantageous embodiment, thebulb 21 contains anupper chamber 26 and alower chamber 27 separated by animpervious diaphragm 28.Upper chamber 26 containssilicone gel 29, which acts to seal any puncture inbulb 21 caused by insertion of the liquid-injecting needle.

Disposed inlower chamber 27, fitting snugly therein and substantially covering the base and side walls thereof, is a metal sink or pan 30 having a base 31, aside wall 32, and anaperture 33 in the base 31 registering with thecentral passage 34 in the tube 1 1. Abaffle 35 is spaced from the base 31 by a plurality oflegs 36 to provide free flow of liquid into and from thepassage 34. In this manner, location of the receptacle for injected liquid is facilitated during such operation and the bottom and side walls of the bulb are protected by the metal from punctures due to insertion of the needle. Thediaphragm 28 is suitably extended beyond the exterior wall of thebulb 12 to provide asewing flange 37.Advantageously aperture 33 can be in the form of a plurality of small holes arranged to form a pattern to register with the interior oftube 11 and to be protected bybaffle 35. Theelastomer bulb 21 is then provided with aprotective coating 22 of silicone rubber which is reinforced with Dacron mesh or the like. Suitably,diaphragm 28 with itsflange portion 37 is also of such reinforced rubber. There are also sometimes provided a pair of diametrically disposed anchor orsewing tabs 38, 39, preferably disposed transversely or at right angles to the direction of curvature of theannulus 10 and affixed to its outer surface to enable suturing to adventitia of the artery so that the device remains in stable position on the artery being treated.

In using the device of this invention, the pulmonary artery 40 is made accessible by suitable, known surgical procedures, and the artery 40 is inserted within theannulus 10 by way of the opening 16, which may be pulled apart or enlarged as necessary, thering 10 being quite flexible. After placement of the artery 40 in theannulus 10, ends 24 and 25 ofannulus 10 which extend beyond closed ends 14 and 15 thereof may be trimmed if necessary by the surgeon and are then sewn together, suitably using heavy ligatures. Thebulb 12 is placed on top of the sternum (not shown) just below the skin where it can be located later by palpation and easily reached by a hypodermic needle to fill or empty the bulb l2 and, through it and connecting tube 1 1, the annulus l0 and theinflatable annulus 10, to inflate and force inwardlydistensible portion 13 to constrict the artery 40 as desired, as shown in FIG. 3. The incision in the patient is then closed by the surgeon in the usual manner, the implanted device remaining entirely subcutaneously disposed.

In use of the device after it is emplaced and any incision closed, thehollow bulb 12 is located by palpation and is filled by means of a hypodermic needle, as noted above, introducing a fluid such as 0.9 percent aqueous saline, which flows through the connectingtube 11 into the hollow interior of theannulus 10 causing theinner wall 27 to distend and constrict theartery 26, reducing flow of blood therethrough. The flow of pressure fluid can be aided by manual pressure on thebulb 12. Fluid can be withdrawn, when desired, also by means of a needle. In each case the interior layer of the bulb l2 seals itself, as described.

It will be understood that the above specific description and the drawings have been given for purposes of illustration only and that variations and modifications can be made therein without departing from the spirit and scope of the appended claims. For instance, instead of a permanently fluid pressure substance, thebulb 12 can be filled with a fluid plastic mixed with a catalyst which will cause it to harden in a predetermined time after it fills the inflatable element.

Having described the invention, what is claimed is:

1. A totally implantable adjustable extravascular occluding band adapted to restrict flow of blood through an artery or other major blood vessel, including in combination:

a flexible, inflatable annulus having an incomplete unclosed, generally circular shape, having two ends, each of which is closed, and having a hollow interior, a distensible inner wall, and a non-distensible outer wall, said inflatable annulus forming an artery-receiving space bounded by said inner wall, having a hollow interior and being adapted to penetration by a hypodermic needle, and comprising an upper chamber, a lower chamber, an impervious diaphragm separating said chambers, silicone rubber gel disposed in said upper chamber,

shield means in said lower chamber to protect said lower chamber from penetration by a needle, said shield means being a metal sink having a bottom and a side wall, said sink fitting snugly within said lower chambersubstantially covering the side wall and base of said chamber, and having an aperture in said bottom registering with the central passage of a flexible connecting tube, and

a non-distensible flexible, twist-resistant tube having a central passage providing a conduit between the interior of said bulb and said hollow interior of said annulus.

2. The band of claim I wherein said diaphragm extends to form an annular flange around said bulb.

3. The band of claim 1 wherein said metal is titanium.

4. The band of claim 1 having a baffle in said sink spaced from and protecting said aperture.

5. The band of claim 1 wherein said sink has an aperture of a plurality of small holes arranged in a pattern to register with said central passage.

6. In an adjustable occluding band adapted to be totally implanted in a human body and to restrict flow of blood through an artery or other major blood vessel, and comprising generally a flexible, inflatable, hollow annulus adapted to receive an artery or other major blood vessel, a needle-penetrable bulb and a nondistensible flexible tube connecting the interior of said annulus and the interior of said bulb,

the improvement wherein said bulb is non-distensible and self-sealing and comprises an upper chamber, a lower chamber an impervious diaphragm separating said chambers, a shield means in said lower chamber to protect said lower chamber from puncture by a needle, said shield means being a metal sink having a bottom and a side wall, said sink fitting snugly within said lower chamber substantially covering said side wall and bottom of said chamber, and having an aperture in said bottom registering with the central passage of said flexible tube, and means to anchor said bulb within said body.

Claims (6)

1. A totally implantable adjustable extravascular occluding band adapted to restrict flow of blood through an artery or other major blood vessel, including in combination: a flexible, inflatable annulus having an incomplete unclosed, generally circular shape, having two ends, each of which is closed, and having a hollow interior, a distensible inner wall, and a non-distensible outer wall, said inflatable annulus forming an artery-receiving space bounded by said inner wall, having a hollow interior and being adapted to penetration by a hypodermic needle, and comprising an upper chamber, a lower chamber, an impervious diaphragm separating said chambers, silicone rubber gel disposed in said upper chamber, shield means in said lower chamber to protect said lower chamber from penetration by a needle, said shield means being a metal sink having a bottom and a side wall, said sink fitting snugly within said lower chamber substantially covering the side wall and base of said chamber, and having an aperture in said bottom registering with the central passage of a flexible connecting tube, and a non-distensible flexible, twist-resistant tube having a central passage providing a conduit between the interior of said bulb and said hollow interior of said annulus.

2. The band of claim 1 wherein said diaphragm extends to form an annular flange around said bulb.

3. The band of claim 1 wherein said metal is titanium.

4. The band of claim 1 having a baffle in said sink spaced from and protecting said aperture.

5. The band of claim 1 wherein said sink has an aperture of a plurality of small holes arranged in a pattern to register with said central passage.

6. In an adjustable occluding band adapted to be totally implanted in a human body and to restrict flow of blood through an artery or other major blood vessel, and comprising generally a flexible, inflatable, hollow annulus adapted to receive an artery or other major blood vessel, a needle-penetrable bulb and a non-distensible flexible tube connecting the interior of said annulus and the interior of said bulb, the improvement wherein said bulb is non-distensible and self-sealing and comprises an upper chamber, a lower chamber an impervious diaphragm separating said chambers, a shield means in said lower chamber to protect said lower chamber from puncture by a needle, said shield means being a metal sink having a bottom and a side wall, said sink fitting snugly within said lower chamber substantially covering said side wall and bottom of said chamber, and having an aperture in said bottom registering with the central passage of said flexible tube, and means to anchor said bulb within said body.

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