MANIPULABLE SPRING GUIDE-CATHETER AND TUBE FOR INTRAVENOUS FEEDING
United States Patent 3757768
This invention is directed to a manipulable, flexible, unitary, combined spring guide-catheter that includes an inner wall portion formed as a continuous helical spring with the helices in contact with each other and an outer wall portion formed from an inert plastic material enclosing the spring in such a manner as to become firmly bonded to the spring while having its outer surface smooth. The distal end of the outer wall extends beyond that of the inner wall to define a hollow tip that is provided with axial and/or radial perforations. A wire stylette is freely carried within the lumen of the inner wall; and the stylette and the spring guide-catheter are separately manipulable by suitable handles attached to the respective proximal ends thereof. A shorter length guide-catheter of this same construction, but without the wire stylette, may be used to replace the rigid tubes heretofore used for intra-venous feeding.
US Patent References:
BALLOON CATHETER
Fogarty et al. - September 1969 - 3467101
VASCULAR CANULA FOR MEDICAL APPLICATIONS
Hoeltzenbein - August 1971 - 3598126
ANTITHROMBOTIC INTRAVASCULAR CATHETER REINFORCED WITH NONKINKING MEANS
Schulte - November 1971 - 3618613
Intravenous catheters
Ballard - September 1962 - 3055361
CATHETER
Leibinzohn - August 1972 - 3687142
BALLOON CATHETER
Fogarty et al. - September 1969 - 3467101
VASCULAR CANULA FOR MEDICAL APPLICATIONS
Hoeltzenbein - August 1971 - 3598126
ANTITHROMBOTIC INTRAVASCULAR CATHETER REINFORCED WITH NONKINKING MEANS
Schulte - November 1971 - 3618613
Intravenous catheters
Ballard - September 1962 - 3055361
CATHETER
Leibinzohn - August 1972 - 3687142
Application Number:
05/241915
Publication Date:
09/11/1973
Filing Date:
04/07/1972
View Patent Images:
Export Citation:
Primary Class:
Other Classes:
604/95.010
International Classes:
A61M25/09; A61M25/00
Field of Search:
128/348-351,343,356,33R,2M,2.5R,DIG.9,214.4
Other References:
US.C.I. Catalogue, 1967, pg. 41.
Primary Examiner:
Truluck, Dalton L.
Parent Case Data:
RELATED APPLICATION
This application is a continuation-in-part of my co-pending application Ser. No. 218,224, filed Jan. 17, 1972 (now abandoned), under the title "Manipulable Combined Spring Guide and Catheter".
Claims:
I claim
1. A flexible spring guide-catheter including an inner wall portion having proximal and distal ends and formed from stainless steel wire as a continuously wound lumen-defining helical spring with the helices thereof in contact with each other, and an uninterrupted externally smooth outer wall portion having proximal and distal ends and formed from an inert halogenated hydrocarbon so applied around said helical spring that its inner surface is firmly bonded thereto and its outer surface remains smooth, the distal end of said outer wall portion extending beyond the distal end of said inner wall portion and shaped to define a hollow tip, said hollow tip being provided with at least one perforation to effect open communication between the exterior and interior thereof, the proximal end of said hollow tip being closely engaged around the distal end of said inner wall portion whereby to prevent the said distal end of said inner wall portion from becoming axially elongated (the proximal portion of exterior and interior thereof).
2. The spring guide-catheter of claim 1 in which said hollow tip is preformed into a curvilinear shape.
3. The spring guide-catheter of claim 1 additionally including a wire stylette freely movable into and out of the lumen of said inner wall portion, and having a length such that when fully inserted into said spring guide-catheter the proximal end of said wire stylette extends proximally beyond the proximal end of said spring guide-catheter a distance sufficient to permit its manipulation from such proximal location, at least the distal end portion of said wire stylette being preformed into a curvilinear shape.
4. The spring guide-catheter of claim 1 additionally including; a wire stylette freely movable within the lumen of said inner wall portion and having a length such that when fully inserted into said spring guide-catheter the proximal end of said wire stylette extends proximally beyond the proximal end of said spring guide-catheter a distance sufficient to permit its manipulation from such proximal location; a first manipulative handle provided with an axial bore to permit free passage of said wire stylette therethrough and removably attached to the proximal end of said spring guide-catheter; and a separate manipulative handle removably attached to the proximal end of said wire stylette proximally of said first manipulative handle.
5. The construction of claim 1 having a length of from about 2.5 to about 10.0 cm. whereby to be capable without physical change for use as a tube for intravenous feeding purposes, and additionally including a fitting rigidly affixed to the proximal end thereof for operative connection to a liquid supply source.
6. The spring guide-catheter of claim 5 wherein said outer wall portion terminates at the distal end of said inner wall portion.
7. The intra-venous feeding tube of claim 5 wherein the distal end of said outer wall portion is cut off at an angle distally of said inner wall portion.
1. A flexible spring guide-catheter including an inner wall portion having proximal and distal ends and formed from stainless steel wire as a continuously wound lumen-defining helical spring with the helices thereof in contact with each other, and an uninterrupted externally smooth outer wall portion having proximal and distal ends and formed from an inert halogenated hydrocarbon so applied around said helical spring that its inner surface is firmly bonded thereto and its outer surface remains smooth, the distal end of said outer wall portion extending beyond the distal end of said inner wall portion and shaped to define a hollow tip, said hollow tip being provided with at least one perforation to effect open communication between the exterior and interior thereof, the proximal end of said hollow tip being closely engaged around the distal end of said inner wall portion whereby to prevent the said distal end of said inner wall portion from becoming axially elongated (the proximal portion of exterior and interior thereof).
2. The spring guide-catheter of claim 1 in which said hollow tip is preformed into a curvilinear shape.
3. The spring guide-catheter of claim 1 additionally including a wire stylette freely movable into and out of the lumen of said inner wall portion, and having a length such that when fully inserted into said spring guide-catheter the proximal end of said wire stylette extends proximally beyond the proximal end of said spring guide-catheter a distance sufficient to permit its manipulation from such proximal location, at least the distal end portion of said wire stylette being preformed into a curvilinear shape.
4. The spring guide-catheter of claim 1 additionally including; a wire stylette freely movable within the lumen of said inner wall portion and having a length such that when fully inserted into said spring guide-catheter the proximal end of said wire stylette extends proximally beyond the proximal end of said spring guide-catheter a distance sufficient to permit its manipulation from such proximal location; a first manipulative handle provided with an axial bore to permit free passage of said wire stylette therethrough and removably attached to the proximal end of said spring guide-catheter; and a separate manipulative handle removably attached to the proximal end of said wire stylette proximally of said first manipulative handle.
5. The construction of claim 1 having a length of from about 2.5 to about 10.0 cm. whereby to be capable without physical change for use as a tube for intravenous feeding purposes, and additionally including a fitting rigidly affixed to the proximal end thereof for operative connection to a liquid supply source.
6. The spring guide-catheter of claim 5 wherein said outer wall portion terminates at the distal end of said inner wall portion.
7. The intra-venous feeding tube of claim 5 wherein the distal end of said outer wall portion is cut off at an angle distally of said inner wall portion.
Description:
THE INVENTION
This invention is generally directed to new and useful improvements in those types of spring guides and catheters that are used for the catheterization of the heart and/or internal vessels of the body during certain diagnostic testing and treating procedures and particularly seeks to provide a novel, unitary, manipulable, combined spring guide and catheter for such purposes.
Although catheters of various constructions and materials have long been known, it has been only relatively recently that catheters and devices for controlling them have been developed to permit their generally successful use in techniques such as those required for coronary arteriography or aortography by percutaneous catheterization.
Currently, such techniques generally require the percutaneous insertion of a sharpened cannula into the lumen of a vein or other vessel, after which a wire guide is inserted through the cannula and advanced through the curvatures of the vessel(s), under fluoroscopic observation, until the distal tip of the guide has reached the position at which the injection of a liquid contrast material, or pressure or other readings taken, in order to commence the diagnostic test or chemo-therapy treatment. After the wire guide has been thus advanced to its then ultimate position, a catheter is inserted thereover and advanced to the point at which its distal end coincides with or extends beyond the distal end of the wire guide. At this stage, the wire guide must be withdrawn in order to allow sufficient volume within the lumen of the catheter to permit the required rate of flow of the injected contrast medium to take place or to permit the taking of pressure or other measurements without the throttling or other effects that may be caused by the presence of the wire guide.
Obviously, such catheterizations are very delicate in nature, requiring manipulative techniques that avoid such problems as the inadvertant perforation of the wall of a vessel, breaking or kinking of the guide due to its mishandling during advance through the curvatures or convolutions of the vessel's lumen, or comparable problems in advancing the catheter over the wire guide. Still further complications can arise during or as a consequence of withdrawing the wire guide in the event that its withdrawal or retraction is improperly effected.
More recently, such problems have been somewhat reduced through the use of guides formed as closely wound helical springs that are more capable of following the various curvilinear paths of the vessel's lumen; and still more recently, these latter types of wire guides have been constructed to permit the manipulation of their distal ends by devices located at their proximal ends.
Even so, it is still necessary to withdraw the wire guide after the catheter has been advanced into place thereover.
However, a combined spring guide and catheter constructed in accordance with this invention overcomes the problems heretofore present in such catheterization procedures and does not require the separate and successive use of a wire guide followed by a catheter, and in a shorter length can be used as a tube for intra-venous feeding.
Therefore, an object of this invention is to provide a novel manipulable unitary spring guide and catheter that can be ued in place of the heretofore used separate spring guides and used
Another object of this invention is to provide a spring guide-catheter of the character stated that is of tubular construction and includes an inner wall portion formed from a continuous helically wound metal spring with the helices thereof in contact with each other and an outer wall portion or sheath formed from an inert plastic material that is shrunk fit over the coils of said inner wall portion.
Another object of this invention is to provide a spring guide-catheter of the character stated in which the distal end of said outer wall portion extends distally beyond the distal end of said spring-defined inner wall portion and is provided with at least one perforation whereby to define a distal tip for open communication with the adjacent portion of the vessel into which said spring guide-catheter has been inserted.
Another object of this invention is to provide a spring guide-catheter of the character stated into which a pre-configured wire stylette may be freely inserted and withdrawn before, during or after insertion of the spring guide-catheter into a body vessel, whereby to assist the guidance or positioning of at least the distal end of the spring guide-catheter.
Another object of this invention is to provide a spring guide-catheter of the character stated in which detachable means are provided for torsionally rotating or oscillating the spring guide-catheter and for advancing, retracting or rotating or oscillating the freely movable wire stylette.
A further object of this invention is to provide a spring guide-catheter of the character stated which is so constructed that its lumen capacity for any given outside diameter is greater than that heretofore available in prior known catheters of corresponding external diameters.
A further object of this invention is to provide a spring guide-catheter of the character stated in which the distal end of the outer wall portion or sheath may be preformed into any desired curvilinear shape.
A further object of this invention is to provide a spring guide-catheter of the character stated in which the material of the spring inner wall is sufficiently radiopaque as to eliminate the need for any additional radiopaque material in order to permit fluoroscopic observation of the guide-catheter as it is advanced, manipulated or retracted.
A further object of this invention is to provide a spring guide-catheter of the character stated in which the outer wall portion is sufficiently strong and well bonded to the spring inner wall portion as to safely contain the spring in the event that it should become broken due to any overviolent mishandling by an operator or to fatigue that may occur through overuse.
A further object of this invention is to provide a guide-catheter of the character stated that, if produced in short lengths and without the wire stylette, can be used as an insertable tube for intra-venous feeding purposes.
A further object of this invention is to provide a spring guide-catheter of the character stated that is simple in design, rugged in construction and economical to manufacture.
With these and other objects, the nature of which will be apparent, the invention will be more fully understood by reference to the drawings, the accompanying detailed description and the appended claims.
In the drawings:
FIG. 1 is an enlarged longitudinal section of a spring guide-catheter constructed in accordance with this invention and shows a straight tip having a single axial perforation at its distal end;
FIG. 2 is an enlarged longitudinal section of the distal end of the spring guide-catheter in which the tip is preformed into a curvilinear shape and is provided with a plurality of lateral perforations;
FIG. 3 is an enlarged detail elevation of the distal end of a control wire stylette that has been preformed into a J-configuration;
FIG. 4 is a view similar to FIG. 3 but showing the wire stylette preformed as a long pitch spiral;
FIG. 5 is an enlarged fragmentary longitudinal section of the proximal end of the spring guide-catheter when attached to typical manipulating handles or devices;
FIG. 6 is a view similar to FIG. 1, but showing a modification of the spring guide-catheter, without the wire stylette, for use as an intra-venous feeding tube;
FIG. 7 is a fragmentary longitudinal section of the distal end of the tube of FIG. 6, but showing its tip biased or cut at an angle; and
FIG. 8 is a fragmentary longitudinal section of or modification of the distal end of the tube of FIG. 6 in which the distally extending hollow tip has been eliminated.
Referring to the drawings in detail the invention, as illustrated, is embodied in a spring guide-catheter generally indicated 5 that may be made in any required length, for example, from 20 cm. to 150 cm. or more, and of a size ranging from a No. 2 to a No. 10 French.
The spring guide-catheter 5 includes an inner wall portion 6 defined by a continuous helical spring wound with the helices thereof in contact with each other and formed from stainless steel spring wire, and an outer portion 7 formed from a tube of smooth, inert, flexible plastic material, such as a halogenated hydrocarbon, that is shrunk-fit, as by heat, over the inner wall portion 6 in such a manner that the outer surface of the plastic tube remains smooth and its inner surface is forced into the spiral grooves on the outer surface of the inner wall portion 6, thus effecting a firm bond between the outer tube and the inner spring.
The tubular outer wall portion 7 extends beyond the distal end of the inner wall portion 6 to define a distally extending straight tip 8 (see FIG. 1) provided at its distal end with an axial perforation 9 to permit open communication between the lumen of the spring guide-catheter 5 and the lumen of the vessel into which the spring guide-catheter is inserted.
Shrinkage of the plastic tube from which the outer wall portion 7 is formed causes a natural slight necking down of the tip 8, as at 10, which locks the distal end of the inner wall spring against axial elongation and also provides a smaller outside diameter for the tip which enhances its advance through a vessel or into a branch thereof.
FIG. 2 of the drawings shows a modification of the distal end of the spring guide-catheter in which the tip 8 thereof is preformed, as by heat-setting, into a curved shape and the axial perforation 9 is replaced by a plurality of lateral or radial perforations 11.
A stylette wire 12, for assisting in the manipulation and control of the spring guide-catheter as it is being advanced into or withdrawn from a vessel, fits freely within the lumen 13 of the spring guide-catheter and is freely movable axially with respect thereto. The stylette wire 12 may be straight as shown in FIG. 1; may have a preformed J-shape 14 at its distal end as shown in FIG. 3; or may have all or a portion of its length formed as a long-pitch spiral 15 as shown in FIG. 4. In any event, the specific configuration or curvature of the wire stylette will be that which has been determined, from manipulative experience, to be the most desirable to enable the spring guide-catheter to be most easily used for the type of catheterization involved.
In use, and common to prior techniques, a sharpened hollow needle or cannulus is first used to gain percutaneous entry to the lumen of a vessel to be catheterized, after which the spring guide-catheter of this invention is employed for the actual catheterization.
At this stage, due to the unitary construction and proportions of this spring guide-catheter, only the single passage of a single device along the lumen of the vessel to be catheterized is required.
By contrast, all prior known techniques have at least required; firstly, the introduction and advance of an independent spring guide to its ultimate position within the lumen of a vessel; secondly, the insertion of a catheter over the previously inserted spring guide with the consequent further abrasion or frictional contact with the walls of the vessel's lumen and a further dilation thereof due to the added thickness of the catheter; and thirdly a complete retraction or withdrawal of the initially implanted spring guide in order to provide sufficient volumetric capacity within the lumen of the implanted catheter to permit the proper infusion of a contrast medium through the catheter or to permit the unobstructed or unthrottled taking of pressure or other measurements therethrough.
Here, even if the stylette wire 12 should be retained within the lumen of the spring guide-catheter 5, there is still sufficient capacity within the lumen to permit proper infusion of a contrast medium under the required pressure or to permit the taking of pressure or other measurements, although such functions would be enhanced if the wire stylette were completely retracted or withdrawn before any such functions are commenced.
It should be pointed out that the fully bonded inner-to-outer wall construction of the spring guide-catheter of this invention enables it to withstand any normally used pressures for the introduction and dispersion of a contrast medium through the distal tip and that the tip itself has a wall strength to withstand such pressures, even though there is a pressure drop in the tip due to the release or discharge of the contrast medium through the perforations thereof.
Manipulation of the spring guide-catheter 5 by torsion in either direction and its advance or retraction within the lumen of a vessel is effected by a handle generally indicated 16 which is removably attached to the proximal end of the spring guide-catheter and provided with an axial bore 17 which initially permits passage of the wire stylette 12 therethrough and subsequently serves as a duct for transmission of the contrast medium or the taking of pressure measurements after the stylette has been fully withdrawn therefrom.
The stylette 12 is manipulated axially and torsionally relative to the spring guide-catheter as the spring guide-catheter is being advanced to assist in the proper directioning thereof during advance. For this purpose, a handle or knob generally indicated 18 is removably attached to the proximal end of the stylette.
It will have become evident from the description thus far, that since only a single device, namely the combined spring guide-catheter of this invention, is required for catheterization in a single pass into a vessel, the time required to effect the fully-controlled catheterization is greatly reduced in comparison with that required by prior known techniques using separate and sequentially inserted spring guides and catheters.
Furthermore, the spring guide-catheter of this invention is so proportioned and constructed that it can be used for the controlled catheterization of smaller diameter vessels than heretofore possible while retaining an adequate capacity for the transmission of a contrast medium therethrough at any desired flow rate and pressure normally used.
For example, it is believed that no prior known sequentially used spring guides and catheters could effectively catheterize vessels having lumens smaller than about 0.72 inch I.D. (inside diameter), since a French No. 5 catheter, having an O.D. (outside diameter) of about 0.65 inch is the smallest that could be used for such a vessel while providing sufficient volume capacity within the catheter lumen to properly transmit a contrast medium under the flow rates and pressures required.
In contrast, a spring guide-catheter constructed in accordance with this invention can be fabricated down to a No. 2 or No. 3 French size (O.D. 0.035 - 0.045 inch) and still have adequate lumen capacity for the transmission of a contrast medium, under the desired flow rates and pressures, without danger of blow out through the walls or of whiplash of the distal end due to reaction from the release or emission of the contrast medium through the perforation(s) of the tip thereof.
As a corrolary, it should also be noted that, on a size-for-size basis, the spring guide-catheter of this invention has a delivery capacity of from about 1.5 to about 1.75 times greater than that of prior catheters per se usable for the same purposes.
Where the tip 8 is provided with the single distal axial perforation 9, as shown in FIG. 1, it has been observed that the discharge of a contrast medium therethrough takes place in a whirling manner about the axis of delivery, thus assuring complete and immediate contact of the contrast medium with all of the adjacent wall portions of the vessel's lumen.
If the length of the tip 8 should extend sufficiently beyond the distal end of the radiopaque spring inner wall 6 that additional radiopaqueness of the tip is required, such can be accomplished by treating all or part of the tip with a supplemental radiopaque material that either is incorporated therein or is separately applied and firmly bonded thereto.
As previously indicated in the objects of this invention and as illustrated in FIGS. 6-8 of the drawings, this spring guide-catheter may be readily modified by reducing its length to from about 2.5-10.0 cm. and by eliminating the wire stylette 12 in order to adapt it for use as a flexible intra-venous feeding tube to replace the heretofore used normally rigid I.V. tubes or hollow needles.
It is believed that, originally, such I.V. tubes were made of a frangible material such as glass, with consequent risks of injury to the patient due to breaking of the tube during or after insertion thereof into a vein or to movements of the patient that would cause discomfort, breaking of the tube or even perforation of the vein wall; or, more recently, were made of a vinyl or other relatively rigid plastic material that eliminated only the breakage problem while introducing the new problem of flow stoppage or reduction due to wall collapse or kinking resulting from a patient's movements.
Such problems, too, are solved through the use of guide-catheter tubes constructed in accordance with this invention since these tubes (1) are not frangible; (2) are strong enough to withstand substantial flexing without being subject to wall collapse or kinking; and (3) are sufficiently flexible as to minimize patient discomfort during movements while at the same time adapting to such patient movements without danger of causing perforation of the vein walls.
For this purpose (see FIG. 6) the guide-catheter 5 still comprises the spring inner wall portion 6, the plastic outer wall portion 7 and the distal tip 8 extending from the necked-down portion 10. However, the distal end of the tip 8 is shorter than that shown in FIG. 1 and is open as at 19 to permit a free flow of the I.V. liquid therethrough; and the handle 16 (shown in FIG. 5) at the proximal end of the guide-catheter 5 is replaced by a female Luer or other suitable fitting 20 for connection with the discharge from the I.V. supply.
Naturally, the lumen capacity of this modification of the guide-catheter will be such as to permit the required flow rate of the I.V. fluid while its outside diameter is small enough to permit its ready insertion into the patient's vein.
Although it is believed desirable in this modification to retain the shortened distal tip 8, since its somewhat smaller diameter enhances the ease of insertion of the I.V. tube into a vein, some technicians may feel that it produces an unnecessary constriction at the distal end. In such cases the tip 8 may be eliminated by terminating the outer wall portion 7 at the distal end of the inner wall portion 6 (see FIG. 8), where its natural tendency to neck-down will simply form a smooth bead 21 at the distal end which still will restrain the inner wall portion 6 against axial elongation.
The distal end of the tip 8 may also be biased or cut off at an angle as shown at 22 in FIG. 7 of the drawings.
For either catheterization of I.V. feeding purposes, percutaneous access to the vein or vessel involved may be gained through the use of a sharpened split cannula or needle through which the guide-catheter or I.V. tube is inserted and which is removed from the patient immediately thereafter.
Whenever the guide-catheter or I.V. tube must remain in place for a substantial length of time, its proximal end may be removably fastened to the patient's skin by adhesive tape, but more preferably through the use of a two part multiple hook fabric fastener, such as that currently available under the trademark "Velcro", in which one part is carried by the proximal end of the tube or guide-catheter and the other part is carried by the exposed surface of a strap or adhesive strip removably fastened to the patient.
It should be further mentioned that, due to the relative low cost of fabrication, the spring guide-catheter of this invention normally will be disposed or discarded after a single use, even though its materials and construction are such that it is capable of being used a plurality of times before being discarded, assuming that it would be properly autoclaved for cleanliness and sterility between uses.
It is of course to be understood that variations in arrangements and proportions of parts may be made within the scope of the appended claims.
This invention is generally directed to new and useful improvements in those types of spring guides and catheters that are used for the catheterization of the heart and/or internal vessels of the body during certain diagnostic testing and treating procedures and particularly seeks to provide a novel, unitary, manipulable, combined spring guide and catheter for such purposes.
Although catheters of various constructions and materials have long been known, it has been only relatively recently that catheters and devices for controlling them have been developed to permit their generally successful use in techniques such as those required for coronary arteriography or aortography by percutaneous catheterization.
Currently, such techniques generally require the percutaneous insertion of a sharpened cannula into the lumen of a vein or other vessel, after which a wire guide is inserted through the cannula and advanced through the curvatures of the vessel(s), under fluoroscopic observation, until the distal tip of the guide has reached the position at which the injection of a liquid contrast material, or pressure or other readings taken, in order to commence the diagnostic test or chemo-therapy treatment. After the wire guide has been thus advanced to its then ultimate position, a catheter is inserted thereover and advanced to the point at which its distal end coincides with or extends beyond the distal end of the wire guide. At this stage, the wire guide must be withdrawn in order to allow sufficient volume within the lumen of the catheter to permit the required rate of flow of the injected contrast medium to take place or to permit the taking of pressure or other measurements without the throttling or other effects that may be caused by the presence of the wire guide.
Obviously, such catheterizations are very delicate in nature, requiring manipulative techniques that avoid such problems as the inadvertant perforation of the wall of a vessel, breaking or kinking of the guide due to its mishandling during advance through the curvatures or convolutions of the vessel's lumen, or comparable problems in advancing the catheter over the wire guide. Still further complications can arise during or as a consequence of withdrawing the wire guide in the event that its withdrawal or retraction is improperly effected.
More recently, such problems have been somewhat reduced through the use of guides formed as closely wound helical springs that are more capable of following the various curvilinear paths of the vessel's lumen; and still more recently, these latter types of wire guides have been constructed to permit the manipulation of their distal ends by devices located at their proximal ends.
Even so, it is still necessary to withdraw the wire guide after the catheter has been advanced into place thereover.
However, a combined spring guide and catheter constructed in accordance with this invention overcomes the problems heretofore present in such catheterization procedures and does not require the separate and successive use of a wire guide followed by a catheter, and in a shorter length can be used as a tube for intra-venous feeding.
Therefore, an object of this invention is to provide a novel manipulable unitary spring guide and catheter that can be ued in place of the heretofore used separate spring guides and used
Another object of this invention is to provide a spring guide-catheter of the character stated that is of tubular construction and includes an inner wall portion formed from a continuous helically wound metal spring with the helices thereof in contact with each other and an outer wall portion or sheath formed from an inert plastic material that is shrunk fit over the coils of said inner wall portion.
Another object of this invention is to provide a spring guide-catheter of the character stated in which the distal end of said outer wall portion extends distally beyond the distal end of said spring-defined inner wall portion and is provided with at least one perforation whereby to define a distal tip for open communication with the adjacent portion of the vessel into which said spring guide-catheter has been inserted.
Another object of this invention is to provide a spring guide-catheter of the character stated into which a pre-configured wire stylette may be freely inserted and withdrawn before, during or after insertion of the spring guide-catheter into a body vessel, whereby to assist the guidance or positioning of at least the distal end of the spring guide-catheter.
Another object of this invention is to provide a spring guide-catheter of the character stated in which detachable means are provided for torsionally rotating or oscillating the spring guide-catheter and for advancing, retracting or rotating or oscillating the freely movable wire stylette.
A further object of this invention is to provide a spring guide-catheter of the character stated which is so constructed that its lumen capacity for any given outside diameter is greater than that heretofore available in prior known catheters of corresponding external diameters.
A further object of this invention is to provide a spring guide-catheter of the character stated in which the distal end of the outer wall portion or sheath may be preformed into any desired curvilinear shape.
A further object of this invention is to provide a spring guide-catheter of the character stated in which the material of the spring inner wall is sufficiently radiopaque as to eliminate the need for any additional radiopaque material in order to permit fluoroscopic observation of the guide-catheter as it is advanced, manipulated or retracted.
A further object of this invention is to provide a spring guide-catheter of the character stated in which the outer wall portion is sufficiently strong and well bonded to the spring inner wall portion as to safely contain the spring in the event that it should become broken due to any overviolent mishandling by an operator or to fatigue that may occur through overuse.
A further object of this invention is to provide a guide-catheter of the character stated that, if produced in short lengths and without the wire stylette, can be used as an insertable tube for intra-venous feeding purposes.
A further object of this invention is to provide a spring guide-catheter of the character stated that is simple in design, rugged in construction and economical to manufacture.
With these and other objects, the nature of which will be apparent, the invention will be more fully understood by reference to the drawings, the accompanying detailed description and the appended claims.
In the drawings:
FIG. 1 is an enlarged longitudinal section of a spring guide-catheter constructed in accordance with this invention and shows a straight tip having a single axial perforation at its distal end;
FIG. 2 is an enlarged longitudinal section of the distal end of the spring guide-catheter in which the tip is preformed into a curvilinear shape and is provided with a plurality of lateral perforations;
FIG. 3 is an enlarged detail elevation of the distal end of a control wire stylette that has been preformed into a J-configuration;
FIG. 4 is a view similar to FIG. 3 but showing the wire stylette preformed as a long pitch spiral;
FIG. 5 is an enlarged fragmentary longitudinal section of the proximal end of the spring guide-catheter when attached to typical manipulating handles or devices;
FIG. 6 is a view similar to FIG. 1, but showing a modification of the spring guide-catheter, without the wire stylette, for use as an intra-venous feeding tube;
FIG. 7 is a fragmentary longitudinal section of the distal end of the tube of FIG. 6, but showing its tip biased or cut at an angle; and
FIG. 8 is a fragmentary longitudinal section of or modification of the distal end of the tube of FIG. 6 in which the distally extending hollow tip has been eliminated.
Referring to the drawings in detail the invention, as illustrated, is embodied in a spring guide-catheter generally indicated 5 that may be made in any required length, for example, from 20 cm. to 150 cm. or more, and of a size ranging from a No. 2 to a No. 10 French.
The spring guide-catheter 5 includes an inner wall portion 6 defined by a continuous helical spring wound with the helices thereof in contact with each other and formed from stainless steel spring wire, and an outer portion 7 formed from a tube of smooth, inert, flexible plastic material, such as a halogenated hydrocarbon, that is shrunk-fit, as by heat, over the inner wall portion 6 in such a manner that the outer surface of the plastic tube remains smooth and its inner surface is forced into the spiral grooves on the outer surface of the inner wall portion 6, thus effecting a firm bond between the outer tube and the inner spring.
The tubular outer wall portion 7 extends beyond the distal end of the inner wall portion 6 to define a distally extending straight tip 8 (see FIG. 1) provided at its distal end with an axial perforation 9 to permit open communication between the lumen of the spring guide-catheter 5 and the lumen of the vessel into which the spring guide-catheter is inserted.
Shrinkage of the plastic tube from which the outer wall portion 7 is formed causes a natural slight necking down of the tip 8, as at 10, which locks the distal end of the inner wall spring against axial elongation and also provides a smaller outside diameter for the tip which enhances its advance through a vessel or into a branch thereof.
FIG. 2 of the drawings shows a modification of the distal end of the spring guide-catheter in which the tip 8 thereof is preformed, as by heat-setting, into a curved shape and the axial perforation 9 is replaced by a plurality of lateral or radial perforations 11.
A stylette wire 12, for assisting in the manipulation and control of the spring guide-catheter as it is being advanced into or withdrawn from a vessel, fits freely within the lumen 13 of the spring guide-catheter and is freely movable axially with respect thereto. The stylette wire 12 may be straight as shown in FIG. 1; may have a preformed J-shape 14 at its distal end as shown in FIG. 3; or may have all or a portion of its length formed as a long-pitch spiral 15 as shown in FIG. 4. In any event, the specific configuration or curvature of the wire stylette will be that which has been determined, from manipulative experience, to be the most desirable to enable the spring guide-catheter to be most easily used for the type of catheterization involved.
In use, and common to prior techniques, a sharpened hollow needle or cannulus is first used to gain percutaneous entry to the lumen of a vessel to be catheterized, after which the spring guide-catheter of this invention is employed for the actual catheterization.
At this stage, due to the unitary construction and proportions of this spring guide-catheter, only the single passage of a single device along the lumen of the vessel to be catheterized is required.
By contrast, all prior known techniques have at least required; firstly, the introduction and advance of an independent spring guide to its ultimate position within the lumen of a vessel; secondly, the insertion of a catheter over the previously inserted spring guide with the consequent further abrasion or frictional contact with the walls of the vessel's lumen and a further dilation thereof due to the added thickness of the catheter; and thirdly a complete retraction or withdrawal of the initially implanted spring guide in order to provide sufficient volumetric capacity within the lumen of the implanted catheter to permit the proper infusion of a contrast medium through the catheter or to permit the unobstructed or unthrottled taking of pressure or other measurements therethrough.
Here, even if the stylette wire 12 should be retained within the lumen of the spring guide-catheter 5, there is still sufficient capacity within the lumen to permit proper infusion of a contrast medium under the required pressure or to permit the taking of pressure or other measurements, although such functions would be enhanced if the wire stylette were completely retracted or withdrawn before any such functions are commenced.
It should be pointed out that the fully bonded inner-to-outer wall construction of the spring guide-catheter of this invention enables it to withstand any normally used pressures for the introduction and dispersion of a contrast medium through the distal tip and that the tip itself has a wall strength to withstand such pressures, even though there is a pressure drop in the tip due to the release or discharge of the contrast medium through the perforations thereof.
Manipulation of the spring guide-catheter 5 by torsion in either direction and its advance or retraction within the lumen of a vessel is effected by a handle generally indicated 16 which is removably attached to the proximal end of the spring guide-catheter and provided with an axial bore 17 which initially permits passage of the wire stylette 12 therethrough and subsequently serves as a duct for transmission of the contrast medium or the taking of pressure measurements after the stylette has been fully withdrawn therefrom.
The stylette 12 is manipulated axially and torsionally relative to the spring guide-catheter as the spring guide-catheter is being advanced to assist in the proper directioning thereof during advance. For this purpose, a handle or knob generally indicated 18 is removably attached to the proximal end of the stylette.
It will have become evident from the description thus far, that since only a single device, namely the combined spring guide-catheter of this invention, is required for catheterization in a single pass into a vessel, the time required to effect the fully-controlled catheterization is greatly reduced in comparison with that required by prior known techniques using separate and sequentially inserted spring guides and catheters.
Furthermore, the spring guide-catheter of this invention is so proportioned and constructed that it can be used for the controlled catheterization of smaller diameter vessels than heretofore possible while retaining an adequate capacity for the transmission of a contrast medium therethrough at any desired flow rate and pressure normally used.
For example, it is believed that no prior known sequentially used spring guides and catheters could effectively catheterize vessels having lumens smaller than about 0.72 inch I.D. (inside diameter), since a French No. 5 catheter, having an O.D. (outside diameter) of about 0.65 inch is the smallest that could be used for such a vessel while providing sufficient volume capacity within the catheter lumen to properly transmit a contrast medium under the flow rates and pressures required.
In contrast, a spring guide-catheter constructed in accordance with this invention can be fabricated down to a No. 2 or No. 3 French size (O.D. 0.035 - 0.045 inch) and still have adequate lumen capacity for the transmission of a contrast medium, under the desired flow rates and pressures, without danger of blow out through the walls or of whiplash of the distal end due to reaction from the release or emission of the contrast medium through the perforation(s) of the tip thereof.
As a corrolary, it should also be noted that, on a size-for-size basis, the spring guide-catheter of this invention has a delivery capacity of from about 1.5 to about 1.75 times greater than that of prior catheters per se usable for the same purposes.
Where the tip 8 is provided with the single distal axial perforation 9, as shown in FIG. 1, it has been observed that the discharge of a contrast medium therethrough takes place in a whirling manner about the axis of delivery, thus assuring complete and immediate contact of the contrast medium with all of the adjacent wall portions of the vessel's lumen.
If the length of the tip 8 should extend sufficiently beyond the distal end of the radiopaque spring inner wall 6 that additional radiopaqueness of the tip is required, such can be accomplished by treating all or part of the tip with a supplemental radiopaque material that either is incorporated therein or is separately applied and firmly bonded thereto.
As previously indicated in the objects of this invention and as illustrated in FIGS. 6-8 of the drawings, this spring guide-catheter may be readily modified by reducing its length to from about 2.5-10.0 cm. and by eliminating the wire stylette 12 in order to adapt it for use as a flexible intra-venous feeding tube to replace the heretofore used normally rigid I.V. tubes or hollow needles.
It is believed that, originally, such I.V. tubes were made of a frangible material such as glass, with consequent risks of injury to the patient due to breaking of the tube during or after insertion thereof into a vein or to movements of the patient that would cause discomfort, breaking of the tube or even perforation of the vein wall; or, more recently, were made of a vinyl or other relatively rigid plastic material that eliminated only the breakage problem while introducing the new problem of flow stoppage or reduction due to wall collapse or kinking resulting from a patient's movements.
Such problems, too, are solved through the use of guide-catheter tubes constructed in accordance with this invention since these tubes (1) are not frangible; (2) are strong enough to withstand substantial flexing without being subject to wall collapse or kinking; and (3) are sufficiently flexible as to minimize patient discomfort during movements while at the same time adapting to such patient movements without danger of causing perforation of the vein walls.
For this purpose (see FIG. 6) the guide-catheter 5 still comprises the spring inner wall portion 6, the plastic outer wall portion 7 and the distal tip 8 extending from the necked-down portion 10. However, the distal end of the tip 8 is shorter than that shown in FIG. 1 and is open as at 19 to permit a free flow of the I.V. liquid therethrough; and the handle 16 (shown in FIG. 5) at the proximal end of the guide-catheter 5 is replaced by a female Luer or other suitable fitting 20 for connection with the discharge from the I.V. supply.
Naturally, the lumen capacity of this modification of the guide-catheter will be such as to permit the required flow rate of the I.V. fluid while its outside diameter is small enough to permit its ready insertion into the patient's vein.
Although it is believed desirable in this modification to retain the shortened distal tip 8, since its somewhat smaller diameter enhances the ease of insertion of the I.V. tube into a vein, some technicians may feel that it produces an unnecessary constriction at the distal end. In such cases the tip 8 may be eliminated by terminating the outer wall portion 7 at the distal end of the inner wall portion 6 (see FIG. 8), where its natural tendency to neck-down will simply form a smooth bead 21 at the distal end which still will restrain the inner wall portion 6 against axial elongation.
The distal end of the tip 8 may also be biased or cut off at an angle as shown at 22 in FIG. 7 of the drawings.
For either catheterization of I.V. feeding purposes, percutaneous access to the vein or vessel involved may be gained through the use of a sharpened split cannula or needle through which the guide-catheter or I.V. tube is inserted and which is removed from the patient immediately thereafter.
Whenever the guide-catheter or I.V. tube must remain in place for a substantial length of time, its proximal end may be removably fastened to the patient's skin by adhesive tape, but more preferably through the use of a two part multiple hook fabric fastener, such as that currently available under the trademark "Velcro", in which one part is carried by the proximal end of the tube or guide-catheter and the other part is carried by the exposed surface of a strap or adhesive strip removably fastened to the patient.
It should be further mentioned that, due to the relative low cost of fabrication, the spring guide-catheter of this invention normally will be disposed or discarded after a single use, even though its materials and construction are such that it is capable of being used a plurality of times before being discarded, assuming that it would be properly autoclaved for cleanliness and sterility between uses.
It is of course to be understood that variations in arrangements and proportions of parts may be made within the scope of the appended claims.