US 3570013 A
Abstract available in
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Description (OCR text may contain errors)
March 16, 1971 J, B UM 3,570,013
CARDIAC IMPLANT Filed June 19, 1968 FIG.|
2 V U U "1 W WW W M IMALI,
About 5-20mm. I. D.
INVENTOR LOUIS J. BLUMEN At forneys United States Patent 3,570,013 CARDIAC IMPLANT Louis J. Blumen, 8 Carleton Drive, Pittsburgh, Pa. 15243 Filed June 19, 1968, Ser. No. 738,202
Int. Cl. A61f J /24 US. Cl. 3-1 2 Claims ABSTRACT OF THE DISCLOSURE This patent discloses a cardiac implant for use in supplying arterial blood to portions of the myocardium of a patient. The implant is made of silicone-impregnated woven Dacron, pre-clotted in the patients own blood, and comprises a main portion or tube which separates into a number of branch portions. Each of the branch portions is provided with a number of perforations. The main tube is grafted to the aorta, and the branches are inserted in the myocardium of the patient. Blood-vessel growth will take place in the vicinity of the perforations, so that collateral circulation is provided, e.g., to a heart impaired by coronary thrombosis.
BACKGROUND OF THE INVENTION (1) Field of the invention This invention relates to prosthetic devices, and in particular, to an artificial blood vessel useful as a cardiac implant.
(2) Description of the prior art It is known that a myocardial infarction (heart attack) results from a clot in one of the coronary arteries, and that downstream of the clot, there is in many cases a bloodpoor area. When a heart attack occurs, the patient survives only if collateral circulation, around the clot, is sufiiciently gOOd to sustain enough of the heart muscle that the heart can continue to operate effectively. With mild heart attacks, natural processes of blood-vessel growth will frequently, in time, supply sufficient collateral circulation that the patient may return to a normal, or near-normal level of activity. With a heart attack somewhat more severe, however, there may be quite a large blood-poor area in the heart muscle, and as a result, it becomes necessary to supply arterial blood to the heart from an exterior source. It is known, for example, that additional blood can be brought to the heart by using the internal mammary artery. The operation is delicate and rather long (about 3 hours), and it cannot be performed if the internal mammary artery is hardened or too small. Moreover, the internal mammary artery cannot be stretched to reach the posterior side of the heart. Yet another drawback is that only a single connection is made to the heart. If it becomes plugged, or if the blood-poor area is of such extent that more collateral circulation is required than can be supplied from the single source, the operation is not successful.
It is also known that a rib or abdominal artery may be used in place of the internal mammary artery. These arteries are even less conventiently located, so that the operation takes even longer.
It is also known, as a way of supplying arterial blood 1 to a blood-poor portion of the heart, to use a vein taken from the patients leg, and connect it between the aorta and the myocardium of the patient. In this way, blood may be supplied to a posterior blood-poor area. This may be done separately or together with the operation in which the internal mammary artery is connected to the myocardium. With this practice, obtaining the vein to be used entails a separate operation. Moreover, only a single site for the start of capillary growth is provided.
It is also known, in the repair of damaged limbs, to replace a damaged length of blood vessel with an insert made of Dacron tubing about 6-30 millimeters in diameter. It is known that the smaller such tubing is, the more likely it is that a clot will develop therein. The vessels to be used in the vicinity of the patients heart are, of course, generally substantially smaller than those of a limb, and though it is to be expected that the higher blood pressure in the vicinity of the heart will help, to some extent, to prevent the development of thromboses, it has not been obvious to those skilled in the art, as of the time of the making of this invention, that Dacron tubing can be used in the vicinity of the heart. Thus, though bifurcated woven Dacron artificial blood vessels have been made and used, it has remained unobvious to those skilled in the art to practice the invention as described hereinbelow.
SUMMARY OF THE INVENTION According to the invention, I provide an artificial blood vessel made of tightly woven Dacron or the like and consisting of a main portion, adapted to be connected to the aorta of the patient, and a plurality of branch portions, each of which is provided with a number of perfo rations to provide sites for the start of blood-vessel growth. The branch portions are embedded in the myocardium of the patient. As it is unnecessary to locate and prepare the patients own arteries, the duration of the operation is considerably shortened. The use of my device provides, moreover, for multiple points of attachment of the device to the heart muscle. In this Way, the posterior part of the heart may be readily treated. If a single branch becomes plugged, the value of the operation is not lost.
BRIEF DESCRIPTION OF THE DRAWINGS A complete understanding of the invention may be obtained from the foregoing and following description thereof, taken together with the accompanying drawings, in which:
FIG. 1 is a perspective view of a device in accordance with my invention; and
FIG. 2 is a representation of the manner in which the device of FIG. 1 is used.
DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in FIG. 1, the device of the present invention comprises a main portion 2 and a plurality of branch portions 4, 6 and 8. Preferably, there are three branch portions, but a smaller or larger number may be used if desired. Each of the branches 4, 6 and 8 is provided with a number of perforations 10, which serve as sites for the beginning of blood-vessel growth.
The insert must be made of fiber sufficiently tightly woven as to retain the blood, but not so tightly Woven as to prevent certain cells from passing from the exterior to the interior thereof to develop an endothelium. For example, there may be used a dense weave yielding a Wesolowski value of about 10 to 50 cubic centimeters of water passed per minute per square centimeter under a head of millimeters of mercury.
It is within the skill of the art to devise fabric Woven to suit the requirements of the invention, using, for example, 70-denier 34-filament Dacron yarn. The main portion has an internal diameter of about 5 to 20 millimeters and each of the branch portions has an internal diameter of about 3 to 10 millimeters.
If desired, the fibers may be impregnated with silicone or similar suitable material. Silicone impregnation reduces the tendency to form unwanted clots that may travel in the blood-stream.
As is usual in the use of woven-fiber artificial blood vessels, the insert is immersed in the patients blood, clotted, and then squeezed out before being used.
The perforations 10 may be provided in the cardiac implant as it is made by its manufacturer, for example, by piercing the woven fabric with a red-hot needle or possibly by weaving the implant so as to leave openings of the proper size, Alternatively, the perforations 10 may be made by the surgeon while the operation is being done, by drawing a suture thread through a branch portion of the implant in the vicinity where a perforation 10 is to be provided, drawing on the ends of the suture thread to put up a portion of the implant, and then using scissors to snip off a little of the wall of the implant to leave a perforation 10 therein. This procedure will in many instances prove preferable, as it permits the perforations 10 to be placed as desired, having in mind the particular needs of the patient.
As shown in FIG. 2, the device is used by suturing of the main portion 2 to the aorta 12 of a heart 14, and then inserting the branches 4, 6 and 8 in the myocardium 16 f the heart 14.
By means of an eyed tool, the surgeon pierces the epicardium and the myocardium of the heart so as to produce a passage. Then, an end of one of the branch portions 4, 6 and 8 is inserted through the eye of the tool, preferably having been first constricted by means of a suture thread (which is laterremoved) and the tool is withdrawn until the branch 4, 6 0r 8 has been drawn into the myocardium 16 to a desired extent. The branch 4, 6 or 8 is then sutured to the epicardium as at 18, whereafter the tool may be withdrawn to leave the branch portion 4, 6 or 8 in place.
While I have shown and described herein a certain embodiment of my invention, I intend to cover as well any change or modification therein which may be made without departing from the spirit and scope of the invention.
I claim as my invention:
1. An insert for use in the treatment of coronary insufficiency, said insert being formed of woven fiber which is sufficiently tightly woven so as to retain blood therein without free passage of blood from the interior to the exterior thereof, said insert having a main portion with one end adapted for connection to the aorta of the heart and a plurality of branch portions connected to said main portion at the end thereof opposite to said one end, said branch portions being adapted for insertion into passages pierced into the myocardium of the heart, each of said branch portions having a plurality of spaced perforations therein etxending along its length, the size of said perforations being such as to permit blood to freely flow from the interior to the exterior of said branch portions to supply blood to the myocardium of the heart, said main portion having an internal diameter of about 5 to 20 millimeters and each of said branch portions having an internal diameter of about 3 to 10 millimeters.
2. An insert as defined in claim 1, characterized in that said insert is impregnated with silicone.
References Cited UNITED STATES PATENTS 8/1955 Stone 3-1 4/1961 Liebig 3-1 US. Cl. X.R.