Controllable tip guide body and catheter

BACKGROUND OF THE INVENTION

It is often desired to place a catheter or other instrument at a particular point in a body lumen, such as a blood vessel, which is difficult of access. In selective angiography, for example, the blood vessel often must be entered at some remote point and the catheter or instrument guided into a selected branch as it is pushed along through the vessel. The necessary guidance to effect entry into the selected branch involves the two variables of bending and orientation of bending.

The change of direction has generally been accomplished heretofore by the use of prebent catheter tips. This has advantages for certain purposes but the configuration of the bend cannot be changed after the catheter has been inserted in the vessel and it is difficult to orient the bend in the desired direction because of the torsional flexibility of the catheter tube.

Short and rigid controllable tip devices have also heretofore been proposed for special purposes in which the degree of bending of the tip could be controlled from a handle but such devices have not been satisfactory for vascular purposes were the catheter must be long, slender and flexible throughout its entire length- It is desireable to provide precise control of the orientation of the bendable tip as well as the degree of bending and it is further desirable to afford greater flexibility in the manner in which such instruments may be used in blood vessels and other body lumens. Torsional rigidity is necessary for control of orientation.

SUMMARY OF THE INVENTION

This invention relates to an improved controllable tip guide body which may be used to guide a catheter tube or other instrument into a relatively inaccessible location in a blood vessel or other body lumen and to an improved intralumenal device including such a guide body.

The present instrument comprises a handle detachably con- ₄θ nected with an injection tube unit. A catheter outer body may be detachably mounted on the latter. The handle carries a controllable tip guide body which extends through the injection tube unit and catheter outer body and is removable therefrom. The guide body is freely flexible in bending but tor- ₄₅sionally rigid. It has a tip which is bendable in one direction. Devices are provided on the handle for bending and rotating the tip. Means are provided on the injection tube unit for sliding the catheter outer body on the guide body to expose or sheath the bendable tip. Means are also provided for locking 50 the bending and sliding adjustments in selected positions.

The detachable connections are arranged in such a way that the guide body may be inserted into the vessel first and then the catheter outer body applied over the guide body, or the catheter outer body may be first inserted in the vessel and then 55 the guide body inserted through the catheter. After the catheter has been inserted to its desired position in the vessel or other lumen, the handle and guide body may be removed from the injection fitting and catheter. The injection tube unit may be used to introduce an X-ray opaque dye through the 60 catheter either while the guide body remains in the catheter or after the guide body has been removed. These capabilities provide a flexibility of operation which is of great advantage to the surgeon and which has not been available in prior instruments.

Objects of the invention are, therefore, to provide an improved controllable tip guide body for a catheter and other purposes, to provide a controllable tip guide body in which the degree of bending may be controlled and locked in selected adjustment on a handle part, to provide a controllable tip 70 guide body and catheter combination in which the guide body tip may be sheathed and unsheathed by the catheter, to provide a catheter probe assembly having an inner guide body which is rotatable within a nonrotatable catheter outer body, to provide an improved injection tube unit for a catheter of 75 the type described to provide a handle having a controllable tip guide body and detachable injection tube unit and catheter wherein the guide body is removable along with the handle from the injection tube unit and catheter and to provide an in5 strument of the type described in which the several parts may be used in different combinations and as a complete assemblage.

The foregoing and other objects and advantages will become apparent and the invention will be better understood •θ with reference to the following description of the preferred embodiment illustrated in the accompanying drawings. Various changes may be made, however, in the details of construction and arrangement of the parts and certain features may be 15 used without others. All such modifications within the scope ³ of the appended claims are included in the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevation view of a complete instrument em20 bodying the features of the invention, showing the bendable tip of the guide body unsheathed by the catheter;

FIG. 2 is view similar to FIG. 1, showing the bendable tip sheathed;

FIG. 3 is a longitudinal sectional view of the handle of the 25 instrument, showing the palm lever in relaxed position

FIG. 4 is an elevation view of the handle, with parts broken away, showing the palm lever in actuated position;

FIG. 5 is a view on the line 5-5 in FIG. 3;

FIG. 6 is a view on the line 6-6 in FIG. 3;

™ FIG. 7 is a view on the line 7-7 in FIG. 3;

FIG. 8 is an exploded perspective view of the slide in FIGS.

and 4;

FIG. 9 is a longitudinal sectional view of the injection tube ₃5 unit;

FIG. 10 is a view on the line 10-10 in FIG. 9;

FIG. 11 is an enlarged fragmentary sectional view showing a portion of the handle and a portion bf the injection tube unit;

FIG. 12 is an elevation view of the catheter outer body;

FIG. 13 is an elevation view of the controllable tip guide body, with parts broken away, showing the tip in straight position

FIG. 14 is a view similar to FIG. 13, showing the tip in bent position;

FIG. 15 is an enlarged longitudinal sectional view, showing the bendable tip portion of the guide body;

FIG. 16 is a view on the line 16-16 in FIG. 15;

FIG. 17 is an enlarged view on the line 17-17 in FIG. 14; and

FIG. 18 is a view on the line 18-18 in FIG. 17.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The Handle A

The complete instrument comprises a handle A, guide body B, injection tube unit C and catheter outer body D as shown in FIGS, land2.

Referring now to FIG. 3, the operating mechanism in the handle A is carried by a tubular body member 10. Body member 10 has a distal end wall 11 provided with a bore 12 to receive a cylindrical rotator support 13. The rotator support is fixedly secured in this bore by setscrews 14. Extending through the rotator support is n axial passageway 15 which 65 opens into a socket 16 in the outer end of the rotator support. The inside of socket 16 is provided with a plurality of longitudinal grooves 17. Rotatably mounted on the outside of socket 16 is a threaded support collar 20 for connecting the injection tube unit C with handle A

A knurled cylindrical rotator 21 is rotatably mounted on Teflon balls 22 on the inner end of support 13. These balls are introduced through a radial bore 23 which is closed by a screw plug 24. An index fitting 25 is fixedly mounted by press fit in rotator 21. This fitting has an axial passageway 26 in alignment with passageway 15. A pair of longitudinal grooves 27

3,552,384 intersect opposite sides of passageway 26 to form a transversely elongated slot extending through the length of index fitting 25. The adjacent ends of passageways 15 and 26 are chamfered at 28. The distal end of passageway 26 is counterbored to form an enlarged circular end portion 29 having a seating shoulder at 30. The proximal end of guide body B extends through passageway 15 and seats against shoulder 30. The proximal end of passageway 26 is chamfered at 31. An axial tube 35 is soldered onto the proximal end of index fitting 25, this tube being provided with a pair of longitudinal slots 36.

A lever bracket 40 is detachably mounted in body 10 by means of thumb screw 41. A forwardly extending palm lever 42 is pivotally mounted on a pin 43 in ears 44 on the bracket 40 as shown in FIG. 6. In order to reduce friction, the pin 43 is preferably equipped with an oil-less nylon bushing 45.

A slide bracket 46 is mounted on lever bracket 40 by means of screws 47. Slide bracket 46 is bored to receive a bushing 48 for a cylindrical slide 50 which is adapted to reciprocate and rotate in the bushing 48. Slide 50 is urged toward the left in FIG. 3 by a compression spring 51 which is seated at its opposite ends on the bushing 48 and a support washer 52 which is rotatable on the slide. Washer 52 abuts a radial flange 53 on the slide. The distal end of slide 50 is equipped with a pair of radial guide pins 54 which are disposed in the slots 36 of tube 35. Slide 50 further contains an axial passageway 55 in alignment with the in alignment with the passageways 15 and 26, the distal end of passageway 55 being chamfered at 56.

Palm lever 42 is in bell crank shape having a forked inner end 60 which straddles slide 50 on the proximal side of slide bracket 46. The end 60 is rounded to function as a cam and is normally held in a limit position against slide bracket 46 by a cam washer 61 on the slide. Washer 61 is mounted so that it rotates when the slide 50 rotates, by means of a setscrew 62 which enters a longitudinal slot 63 in the slide. The position of washer 61 is fixed by a retainer 65 which bears against a thrust abutment in the form of a two-part stop washer 66. Washer 66 is mounted in a circumferential groove 67 in slide 50 as best shown in FIG. 8. The position of washer 66 is fixed by its abutment against the right side of groove 67 as shown in FIG. 3.

When palm lever 42 is squeezed toward body 10 as shown in FIG. 4, its cam-shaped inner end 60 bearing against washer 61 moves slide 50 to the right in FIG. 3, causing pins 54 to slide in slots 36. The purpose of this movement is to retract a pull wire, presently to be described, which bends the tip of guide body B. The proximal end ofthe guide body seats in counterbore 29 and the pull wire extends through passageways 26 and 55 and has its end anchored at the extreme proximal end of slide 50 by means presently to be described. Such squeezing movement of lever 42 compresses the spring 51 and when the squeezing force on the lever is relaxed, the spring acts through washer 61 to return the parts to their FIG. 3 position. Slide bracket 46 acts as a stop for this return movement, as washer 61 presses lever end 60 against the end of bracket 46.

Slide 50 may be rotated at all times by finger and thumb manipulation of rotator 21. Rotator 21 directly rotates the guide body seating bore 29 and indirectly rotates slide 50 through its pins 54. During such rotation, washer 61 slides freely against the inner lever end 60 regardless of the position of the lever.

An adjustable anchor for the guide body pull wire will now be described with reference to FIG. 3. A slide cap 70 is mounted for longitudinal sliding movement on the end of slide 50. For this purpose the slide 50 is provided with a longitudinal tongue 71 which is received in a slot 72 in one side ofthe slide cap. The slide cap is externally threaded at 73 for engagement with an internally threaded adjustment nut 75. The inner end of nut 75 is externally threaded at 74 for connection with the retainer 65, this connection being screwed tightly together so that the retainer will rotate as a part of the nut. Thus, the longitudinal position of nut 75 is fixed by retainer 65 which is confined between stop washer 66 and cam washer 61 so that rotation of the nut causes slide cap 70 to move longitudinally oh slide 50.

Slide cap 70 has a slot for the guide body pull wire with a narrow central portion 76 interconnecting a wider end portion 77 and a hole 78. Wide portion 77 has a seat 80 for a button on the end of the pull wire while hole 78 forms a smooth bore 5 angular passage for insertion of the pull wire from the distal end of the handle. The inner end of this slot communicates with passageway 55 and the proximal end of passageway 55 is chamfered as indicated at 81. - - . .

The proximal end of body 10 is covered by a cap 85 having ¹⁰ an opening 86 therein for the adjusting nut 75. This cap is secured to handle bracket 40 by screws 87. Mounted on the cap is a locking thumb screw 90 for holding the palm lever 42 in adjusted position. The inner end of this thumb screw has .. threaded engagement with a bore 91 in lever bracket. 40. ¹⁵ Thumb screw 90 extends between the forks of lever end portion 60 and is equipped with an abutment flange 92 which is adapted to bear against the forks. When lever 42 is squeezed toward body 10 in a position to obtain the desired degree of 20 bending in the bendable tip of guide body B, such adjustment may be locked by screwing out the thumb screw 90 Until abutment flange 92 engages the forked lever end 60 as shown in FIG. 4. V ^r’·'By removing thumb screw 41, the entire assemblage of palm 25 lever 42, brackets 40 arid 46, slide 50, and adjustment devices 75 and 90 are removable through the proximal end of handle body 10.

Injection Tube Unit C and Catheter Outer Body D ³⁰ Referring now to FIG. 9, the injection tube unit C comprises an injection tube 100 slidably mounted in a guide tube 101. The guide tube has a threaded proximal end 102 for detachable connection with support collar 20 on the handle A and a , projection 103 to fit in the socket 16 as shown in FIG. 11.

³⁵ Lands 104 fit in grooves 17 so that the unit will fit in the handle in different rotative positions but will be fixedly held against relative rotation.

A stop screw 105 in tube 100 extends through a longitudinal 40 slot 106 in guide tube 101. Tightening screw 105 clamps the two parts in adjusted position arid loosening the screw permits longitudinal movement of the injectiori tube 100 in the guide tube 101 within the rarige of travel allowed by end stops .107 and 108. The injection tube is shown fully retracted in FIGS. 1 45 and 9 and fully extended in FIG. 2.

Injection tube 100 has an axial passageway 110 for the guide body B. The distal end of the injection tube is provided with a branch fitting 111 communicating with passageway Γ10 and immediately on the proximal side of branch 111 is a shu50 toff valve 112 to open and close passageway 110. The distal extremity of tube 100 is threaded at 113 for connection with the catheter outer body D. Fitting 111 may be used for injecting dye or medication through catheter outer body D, for withdrawing a blood sample or for taking blood pressure mea³³ surements.

The proximal end of injection tube 100 is threaded at 119 to receive a squeeze nut 120 containing a resilient rubber O-ring 121. Nut 120 is adjusted to squeeze the O-ring sufficiently to ,- effect a seal with the guide body B at the end of passageway ⁶⁰ 110 while still permitting the guide body, to be inserted and removed through the O-ring, as shown in FIG. 11. Thus, when valve 112 is open and guide body B is in place in passageway 110, the passageway is sealed by O-ring 121 so that fluid in65 jected through branch 111 cannot escape from tube 100 and enter the handle A. When the guide body is removed in a proximal direction, valve 112 is closed: as soon as the distal end of the guide body has cleared the valve in FIG; 9 but before the end of the guide body has cleared the seal 121. After 70 the guide body has been completely withdrawn, the valve 412 prevents any fluid in branch 11Γ arid outer body D from escaping from tube 100. :

The catheter outer body D is shown in FIG. 12. This is simply a flexible plastic tube 125 having a screw threaded 75 fitting 126 on its proximal end for connection Wit the threaded

3,552,384 member Ϊ13 in FIG 9. The distal end 127 of tube 125 is open so that guide body B may be projected as shown in FIG. 2 and for the other purposes mentioned.

Guide Body B

Guide body B is illustrated in FIGS. 13 to 18. This guide body comprises a flexible plastic tube 140 having a tip end portion 141 equipped with a bending element. The proximal end is equipped with a proximal end fitting 142 and extending through this fitting is a flexible pull wire 150 equipped with a button 151 on its end.

Pull wire 150 extends through a thrust coil 155 which is a coil of spring wire wound on a mandrel with adjacent turns in contact with each other so that the coil is rigid as a column and cannot be compressed lengthwise, although it is freely flexible in bending. The mandrel on which coil 155 is wound is of a suitable size so that the pull wire 150 will be freely slidable therein. Surrounding coil 155 is a tightly wound triple wrap coil 156 of finer wire in three layers as best shown in FIG. 17. The center layer is wound in the opposite direction from the inner and outer layers. That is to say, that if the center layer is wound clockwise, the inner and outer layers are wound counterclockwise. Coil 156 is wound on a mandrel of a size to form an inside coil diameter suitable for insertion of coil 155.

Coil 155 may be omitted if desired. Triple wrap coil 156 in itself provides adequate thrust resistance for the pull wire.

The purpose of the three layer, triple wrap coil 156 is to provide torsional rigidity for guide body B while still retaining free flexibility in bending. Since the middle layer of coil 156 is locked between the inner and outer layers, the middle layer can neither contract nor expand radially when the tube is stressed in torsion in opposite directions of rotation. Also, the inner layer cannot expand in one direction of rotation and the outer layer cannot contract in the opposite direction of rotation. This interna! and external restraint eliminates al! torsional flexibility so that when one end of the tube is rotated about its axis, the opposite end will rotate precisely the same amount.

Such rotation is imparted by the flat tongue 160 on the end of fitting 142 which fits in the grooves 27 of index fitting 25 on the rotator 21 in FIG. 3. Fitting 142 has a flat end surface 161 which seats against the shoulder 30, FIG. 11 shows these parts in assembled relation.

Guide body tube 140 further includes an outer layer of plastic 162 which encloses the wire coil assemblage just described and provides a smooth outer surface to minimize sliding and rotating friction against other objects. Plastic 162 also prevents leakage of any fluid into the coils 155 and 156. Fitting 142 is secured tightly to the tube 140 so as to transmit rotative movements of rotator 21 to the tube. Pull wire 150 slides freely in a bore 163 in the fitting 142.

The distal end of tube 140 is equipped with a tip junction fitting 165 which is likewise securely attached to the tube. The opposite ends of both coils 155 and 156 seat against end walls in the two fittings 142 and 165 as shown. Fitting 165 has a bore 166 slidably receiving the pull wire 150. Fitting 165 has an extension 167 with a flat side 168 offset from bore 166 on which is soldered a proximal end of a metal leaf spring member 170. The distal end of spring leaf 170 is similarly soldered to a tip wire fitting 171. Pull wire 150 extends along one flat side of spring leaf 170 and the end of the pull wire is soldered at 172 to the fitting 171.

Spring leaf 170 and pull wire 150 are enclosed in a cage formed by wrapping a wire 173 around the two elements in spiral configuration. One end of wire 173 is soldered at 174 to spring leaf 170 and fitting 165 and the other end is soldered at 175 to spring leaf 170 and fitting 171. The spiral wrap 173 is sufficiently loose that it does not impede free axial movement of pull wire 150.

The metal parts 165,170,171 and 173 are then coated with a primer and pull wire 15® is coated with a lubricant and a plastic covering 176 is molded around the parts as shown. The plastic bonds itself to the primer coated surfaces but does not adhere to pull wire 150 whereby the latter may slide freely through the plastic and through wire cage 173 for bending the tip 141. During the molding operation the plastic 176 on the tip is merged with the plastic 162 on the tube portion 140 making a smooth surfaced juncture completely covering the fitting 165. The tip 141, however, may be molded separately and attached to the body 140.

When pull wire 150 is drawn through fitting 165, leaf spring 170 is caused to bend, producing the curved tip configuration shown in FIG. 14. Coil 155 in the main tube portion 140 acts as a thrust member to prevent snaking of the whole length of the guide body when the pull wire is tensioned. Thus, the tip 141 may be bent at any angle desired up to 180°.

An advantage of the present form of construction of guide body tube 140 is that this tube may be manufactured conveniently in continuous length and then cut to the desired lengths for different surgical purposes. The bendable tip portions 141 may be standardized and used with any length tube portion 140. This effects distinct economy in manufacture while still permitting the different lengths required by surgeons.

Adjustment nut 75 in conjunction with slide cap 70 in FIG. 3 ailows for reasonable manufacturing tolerance in the length of pull wire 150. In installing guide body B in handle A, the button 151 is inserted in a proximal direction through passageways 15, 26 and 55 until the button appears in wide slot portion 78 of slide cap 70. The depth of insertion is limited by the seating of tube fitting 142 against shoulder 30. If necessary, adjusting nut 75 is turned to retract slide cap 70 into the nut until button 151 is emergent from the slide cap so that guide wire 150 may be passed through the narrow portion 76 of the slot to the upper wide portion 77 in FIGS. 3 and 7. Then nut 75 is rotated in the reverse direction to seat button 151 against the seat 80. This longitudinal adjustment of slide cap 70 thereby compensates for any variation in the distance between button 151 and the proximal end fitting 142 on the tube 140.

When lever 42 is squeezed toward handle body 10, the entire slide 50 is moved rearwardly carrying with it slide cap 70 and nut 75 and causing tip 141 to bend. A desired degree of bending may be retained by means of locking thumb screw 90 is previously described.

Guide body B is removed from handle A by merely returning palm lever 42 to its FIG. 3 position and moving slide cap 70 inwardly by rotating nut 75 until button 151 emerges from the wide slot portion 77. Then pull wire 150 is shifted through narrow slot portion 76 to the opposite wide slot portion 78. Guide body B may then be withdrawn from the distal end of the handle. Passageway 55 and hole 78 are of sufficient width to permit the button 151 to pass freely through the angular juncture.

Operation

The parts A, B, C and D may be assembled in different order and used in different combinations for different purposes.

In One type of use guide body B may be assembled with handle A without injection tube unit C and catheter outer body D. After guide body B has been advanced to its destination in a blood vessel or other body lumen, the handle A maybe removed and catheter outer body D, with or without injection tube unit C, may be introduced over guide body B and inserted into the vessel or lumen to follow the path of the guide body. Then guide body B may be withdrawn if desired, leaving outer body D in the vessel.

Alternatively, the catheter outer body D, with injection tube unit C attached, may be inserted first for a distance into the vessel or lumen and then the guide body B, assembled with handle A, may be pushed through the injection tube unit and catheter outer body and the handle connected with the injection tube unit. Then the complete assemblage may be advanced farther into the vessel or into a branch of the vessel.

3,552,384

In a third alternative, the parts B and D of the complete assemblage may be inserted in the vessel or other lumen. This may be done with the catheter outer body D retracted as shown in FIG. 1 or with the catheter outer body projected to cove the bendable tip of the guide body as shown in FIG. 2. In some cases, it is most effective to proceed with a step-by-step movement advancing first the guide body B and then the catheter outer body D by sliding stop screw 105 back and forth in its slot 106 in FIG. 9 and continuing in this manner until the objective has been reached. In this connection, it will be mentioned that the bendable tip portion 141 of the guide body will bend the catheter outer body D when completely enclosed by the latter, when desired.

The instrument may be used in three different catheterization techniques known as cutdown, percutaneous with separate guide wire and percutaneous using guide body B in place of separate guide wire. The cutdown procedure involves simply cutting through the overlying tissue to obtain access to the desired vessel, then cannulating this vessel and, finally, inserting guide body B and catheter outer body D into this vessel for further advance in the vessel or into a branch vessel.

In the general percutaneous procedure, a conventional flexible guide wire is first inserted into the vessel and then the catheter outer body D is inserted over the guide wire. Injection tube unit C may be assembled to the catheter outer body D optionally before or after the catheter outer body is inserted over the guide wire. Then, the flexible guide wire is removed and guide body B, assembled with handle A, is inserted through injection tube unit C and catheter outer body D for further advance. . .

In the second percutaneous procedure, guide body B is inserted through the needle cannula into the vessel. Then the cannula is removed over the proximal end of guide body B and catheter outer body D is inserted into the vessel over guide body B. Handle A may be assembled to guide body B before or after the guide body is inserted through the needle cannula into the vessel. Likewise, the injection tube unit C may optionally be assembled with the catheter outer body D before or after the latter is inserted into the vessel over guide body B. A surgeon will usually elect to minimize the bulk assembled to intralumenal devices during the installation phases, hence will defer attachment of assemblies and instrumentalities.

Specialized types of catheters may be used instead of the plan tube catheter outer body D. For example, the guide body B is of particular advantage in guiding a double lumen balloon catheter to a desired location in the body. Such catheter is attached to the injection tube unit C for injection of an X-ray contrast medium or localized medication through branch connector 111. With the vessel occluded by inflation of the balloon, washing of the blood is minimized and less contrast dye or medication is required.

The present instrument is also useful in connection with other specialized instrumentalities. For example, in fiber optics visualization guide body B is used as previously described to get an outer body tube D to the desired location within the body. Then the guide body B is removed and a fiber optic device inserted through the outer body D for the visualization study. Similarly, the present instrument may be used to guide the placement of other devices such as flow probes, pressure probes, etc.

For still other purposes, a PH probe, pressure transducer or thermistor is attached to the tip of guide body B which my then be used advantageously in combination with a double lumen balloon catheter. Very selective localized measurements of a variety of kinds are thereby possible concurrently with angiography or administration of medication in a single procedure. Such modifications are applicable to systems other than vascular, such a the urinary system.

The foregoing examples are merely illustrative of the wide variety of uses of the present instrument. Still other applications are possible and the field of use is not intended to be limited to the specific examples cited.

The handle A is easily taken apart for cleaning and autoclaving and is reusable indefinitely as is also the injection tube unit C. Guide body B is intended to be reusable for a limited time. Catheter outer body D is essentially a single-use, disposable device, although it may be cleaned, sterilized and reused a number of times, if desired.

Two other advantages of major importance are the rotatability of guide body B continuously in one direction without twisting the pull wire 150 and the rotatability of the guide body within the nonrotatable catheter outer body D, In regard to the former, it will be observed in FIG. ..3 that rotator .21 rotates the pull wire anchorage in slide cap 70 together with index fitting 25 which rotates guide body tube 140. There is no restraint upon the degree of rotation. The advantage of the latter is that the smooth inner surface of catheter outer body D imposes less frictional resistance against rotation ofthe guide body than does the inner suiface of a body lumen. This makes it easier to orient the bendable tip.