Angiographic And Arteriographic Catherters

Abstract

An angiographic catheter through which material passes toward a tapered tip and which includes several series of discharge holes arranged in axially spaced radial planes, the total cross sectional area of the holes in each of said planes decreasing as the planes are placed closer to the tip, and which also includes a discharge chamber immediately adjacent the tip, there being a set of proximal holes also aligned in a radial plane and leading backwardly away from the chamber and a small end hole in the tip which also leads to the chamber, all of the holes being formed by punching them from the inside of the catheter outwardly.

Description

Of the catheters manufactured today, there appear to be none which are designed and constructed in such a manner as to make them ideal for angiographic use wherein the catheter is passed through a vein and into one of the major chambers of the heart. When placed within the heart and used for angiographic and arteriographic purposes, a catheter must have the following three properties:

A. It must disperse its material within the cavity as a uniform, well defined bolus at variable injection rates using a minimum of material;

B. It must make such dispersal in such manner that the inner tissues and lining of the heart are not damaged by either "whipping" or axial displacement of the catheter, or by the force of the stream of material as it is dispersed; and

C. The catheter must be constructed in such manner that the discharge ports are free of burrs and particles of catheter material which could enter the heart and cause an embolism reaction therewithin.

Urological catheters, which are the most common, fall short in all three of the above requisites because of design and construction, and there now exists an immediate need for catheters designed and constructed specifically for angiographic usage and which have the above described properties.

It is the object of this invention to provide a catheter designed to satisfy this need.

With the above and other objects in view which will become immediately apparent upon reading this application, my invention resides in the unique and novel form, construction, combination and assembly of the various steps and structures shown in the drawings, described in the specification and claimed in the claims.

IN THE DRAWINGS

FIG. 1 is a side view of my catheter immediately prior to forming the tip;

FIG. 2 is a similar view of the tip forming mandrel with the catheter end shown in phantom;

FIG. 3 is a sectional view of my outer tip forming mold;

FIG. 4 is the same view as FIG. 3 showing the mandrel and mold in the forming position and the catheter shown in phantom;

FIG. 5 is a sectional view of the formed tip;

FIG. 6 is a sectional view of the block and punch utilized to punch reverse ports of the formed tip;

FIG. 7 is a view of the completed tip;

FIG. 8 is a fragmentary sectional view taken along lines 8--8 of FIG. 7; and

FIGS. 9, 10 and 11 are sectional views taken along lines B--B, C--C and D--D respectively of FIG. 7.

Referring now in more detail and by reference character to the drawings, A represents a catheter comprising a length of catheter tubing 20 (usually 1 meter in length) having an open end 22 with prepunched axially spaced sets of distal holes 24, 26 and 28. The holes 24 are equal to each other in size and in radial registration about plane C--C. Similarly, the holes 26 are larger than the holes 24 and are also equal to each other in size and in radial registration about plane D--D. Furthermore, the holes 28 are larger than the holes 26 and are equal to each other in size and in radial registration about plane E--E. It should be here noted that each of the planes C--C, D--D and E--E are radial to the longitudinal axis of the catheter A.

Provided for forming the tip 30 of the Catheter A, is a mandrel 32 and mold 34. The mandrel 32 comprises an elongated flexible push wire 36 sized in length for passage through the tubing 20 and provided on its forward end with a diametrally reduced neck 38, an enlarged button-like head 40 and a tip 42. The mold 34 comprises an elongated tubular shell 44 terminated at one end with an outwardly flanged tip 46 and at the other end with a taper 48 provided with a bore 50 sized for accepting the tip 42 of the mandrel 32.

The tip 30 is formed by inserting the mandrel 32 in the tube A as seen in FIG. 2 in such manner that the head 40 is nestedly disposed therewithin at the end of the tubing 20 and the tip 42 projects outwardly therefrom. Thereafter the mold 34 is heated and the tubing 20 and mandrel 32 are urged into the heated mold 34 and allowed to cool. After sufficient time has elapsed for the material of the tubing 20 to conform to the shape of the mandrel 32 and the mold 34 and thereafter cool, the mold 34 is removed and the mandrel 32 is "popped" out of the tubing 20.

After the tip forming process is completed, the tip 30 of the catheter A will have an outer taper 54 and an inner neck 56, a diametrically reduced end hole 58, and a diametrically enlarged chamber 60 therebetween.

The catheter A is completed by punching proximal holes 62 in the tip 30. This is accomplished by using a jig 64 and a punch 66. The jig 64 comprises a block 68 of material provided at one end with a tapered bore 70 sized for snug-fitting nested disposition about the tip 30. The depth of the bore 70 is such that the end 72 of the block 66 will lie in registration with the slots 26 for purposes presently more fully to appear. The jig 64 also includes a guide bore 74 sized for accepting the tip 76 of the punch 66 and guiding the same through the end hole 58 and the chamber 60 through the wall of the catheter 20 to punch one hole 62. Ideally, the jig 64 is provided with opposing recesses 78, 80 to accommodate the handle 82 and the tip 76 of the punch 66. The core of the punch 66 is hollow so that as the hole 62 is punched, the catheter material which is removed becomes imbedded in the hollow portion of the tip 76. Slidably disposed in the hollow portion of the punch 66 is a material ejection pin 84 which may be utilized to eject the catheter slug 88 removed in the punching of the hole 62, as best seen in FIG. 6.

Since, as will be pointed out later, registration of alternating sets of holes is important to the operation of my invention, the end of the jig 64 is provided with a notch 90 (or other suitable indicia means) to permit the registration of the proximal holes 62 as they are punched and the holes 26, and to cause the proximal holes 62 to lie in plane B--B which is parallel to and spaced from planes C--C, D--D and E--E. It should be also noted that the holes 62 are directed rearwardly away from the end hole 58 for purposes presently more fully to appear.

LOCATION AND SIZING OF THE PERIPHERAL SLOTS

The location, direction and sizing of the holes 62, 24, 26 and 28 is the most critical to the successful operation of my catheter for angiographic purposes. Such location and sizing has been determined as a combined result of engineering study and clinical test. These holes have been designed and positioned in such manner as to produce quickly a bolus of uniform density about the end of the catheter with minimal displacement of the catheter in the heart cavity and without any high pressure jets of material emerging therefrom, or, more simply put, a cloud of uniform density within the cavity about the end of the catheter.

To accomplish this the peripheral holes 24, 26 and 28 are arranged in peripheral spray planes C--C, D--D and E--E which compliment proximal holes spray plane B--B and the end hole 58. It has been found that dispersion of the material is best accomplished using four sets of uniformly spaced distal holes 24, 26 and 28 in each of the planes C--C, D--D and E--E respectively, with the holes 24 and 28 being in axial registration and the holes 26 being angularly displaced by 45.degree. from the registered holes 24 and 28.

As the material moves through the catheter toward the tip 30, the material will first pass plane E--E and the holes 28 associated therewith. It should be noted that these holes 28 present the largest total opening. At plane E--E, some of the material will be urged through the holes 28 and the remainder of the material will proceed toward the tip 30 at slightly slower velocity but slightly increased pressure. As the undispersed material passes plane D--D and the holes 26 associated therewith, the combination of increased pressure and decreased total opening presented by the holes 26 will cause approximately the same amount of material to be dispersed through the holes 26 and the remainder of the material to continue proceeding toward the tip 30 under conditions of even slower velocity and increased pressure. Similarly, approximately the same amount of material will be dispersed through the holes 24, and the balance of the material will proceed through the catheter 20 and into the chamber 60 under even slower velocity and higher pressure. Once the material enters the chamber 60, it will be dispersed evenly out the proximal holes 62 and the end hole 58 under low velocity in the form of a cloud. Thus it should be apparent that the placement of each set of the holes 24, 26, 28 is such that there is no resultant radial forces to cause "whipping", and the proximal holes 62 being directed away from the chamber 60 in a direction opposite the direction of flow through the end hole 58, there are no resultant axial forces to cause axial movement of the catheter within the heart as material is dispersed.

One final item should be noted. In order to acquire the optimum angiographic catheter, it is necessary to form the holes 62, 24, 26 and 28 by punching them from the inside out as shown herein with regard to the holes 62. This technique produces a catheter which is completely smooth on the inside, and in which any burrs or irregularities are on the external surface where such burrs and irregularities may be removed by abrading, or other similar procedures. The resultant catheter is one in which the exposure to the danger of embollismic reactions due to the presence of foreign materials being introduced into the heart has for all practical purposes been eliminated.

Although the sets of holes 24, 26 and 28 have been shown as being equiangularly spaced with respect to each other for producing clouds of uniform density, various other configurations may be used provided that each hole used is complimented by an axially opposed hole to balance the forces and to eliminate the possibility of whipping.

Toward this end I have developed a special hole punching tool for punching the holes 24, 26, 28 which is the subject of a separate patent application being filed contemporaneously herewith.

It should be apparent that changes, alterations, substitutions and modifications in the various arrangement, combination, configuration, and steps described herein may be made without departing from the nature and principle of my invention.

Claims

Having thus described my invention, what I claim and desire to secure by Letters Patent is described in the following Claims.

1. An angiographic catheter including

an elongated tube provided at one end with a tapered tip and means for discharging a bolus of fluid of uniform density adjacent the tip,

including a plurality of sets of peripheral discharge openings in the tube, each set being longitudinally spaced from each other set,

each set of openings comprising a plurality of openings in radial registration,

and the cumulative amount of open area in one set of discharge openings being greater than the cumulative amount of open area in the set of discharge openings next closet to the tip.

2. The catheter of claim 1 in which the discharge openings in each set are equiangularly spaced with respect to each other.

3. The catheter of claim 1 in which the discharge openings in each set are equiangularly spaced with respect to each other and there are at least four discharge openings in each set.

4. The catheter of claim 3 in which the discharge openings in every other set of discharge openings are in registration along imaginary lines which are parellel to the longitudinal axis of the tube.

5. The catheter of claim 5 in which each discharge opening is in the shape of an elongated slot with rounded corners.

6. A catheter comprising an elongated tube provided at one end with a tapered tip having a small centrally located end hole, said tip also being provided internally with a narrow neck which is spaced from the end hole to define a chamber between the neck and the end hole, said tip also including a plurality of openings located adjacent the tip rearwardly of the end hole and in communication with the chamber, said tube also being provided rearwardly of the neck with a plurality of sets of distal openings, each of such sets comprising a plurality of similarly sized openings in radial registration and each set being axially spaced longitudinally along the tube from each other set, the size of the distal openings in each set being larger than the size of the distal openings of the other sets closer to the tip but smaller than the size of the distal openings of the sets farther from the tip.

7. The catheter of claim 6 in which each of the discharge openings in said chamber is constructed in such manner as to direct the outward flow of the contents of the chamber away from the tip in a direction substantially opposite to the direction of flow through the end hole.

8. The catheter of claim 7 in which there are at least four discharge openings.

9. The catheter of claim 7 in which there are at least four discharge openings and each of the openings are in radial registration and equiangularly spaced.

10. The catheter of claim 6 in which there are the same number of distal openings in each set and the distal openings in each set are regularly spaced with respect to each other.

11. The catheter of claim 10 in which the distal openings of every other set are in registration along imaginary lines which are parallel to the axis of the tube.

12. The catheter of claim 10 in which the distal openings of every other set are in registration along imaginary lines which are parallel to the axis of the tube and the distal openings of the sets therebetween are located centrally between the adjacent distal openings of the next closed set.

13. An angiographic catheter for transmitting material, said catheter comprising an elongated tube and means for balancing hydraulic discharge forces therefrom to prevent whipping and axial movement of said catheter tube during said discharge including, a plurality of forwardly and rearwardly axially directed distal discharge holes located near one end of said tube and also being provided with a tapered tip at said end, said distal holes being located about the longitudinal axis and in the tip of the tube preselectively sized and directed in such manner that the sum of the radial forces created by the discharge of the material through the distal holes is substantially zero.