CA2137153A1 - Catheter with retractable cannula for delivery of chemicals - Google Patents

Abstract

Catheter (11) with a retractable cannula for delivering a plurality of chemicals comprising a flexible elongate member (13) having a centrally disposed lumen (17) and a plurality of circumferentially spaced apart lumens (18-25). An actuator member (31) is slidably mounted in the centrally disposed lumen (17). Springs (56-57) are disposed within the centrally disposed lumen (17) and engage the actuator member (31) for moving the actuator member between extended and retracted positions. A tool (36) having a distal extremity is carried by the actuator member (31) and has a flow passage (38) therein extending through the distal extremity of the tool (36). First and second fittings (48-49) are secured to the proximal extremity of the flexible elongate member (13) in communication with the lumens (18-25) in the flexible elongate element (13). The distal extremity of the flexible elongate member (13) is capable of supplying fluid from said passage lumens (18-25) to the flow passage (38) in the tool (36) when the tool (36) has been advanced to an extended position.

Description

W~93~25263 2137 5 ~ P~T/USg3/0~0 ~THETER WITH RETRACTABLECANNULA FOR DELIVERYOFCHEMICALS

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This invention relates to a catheter with a retractable cannula ~or delivering a plurality of chemicals. ~;
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In the past,~: catheters have been provided for 5~ delivering a chemical to a site within the body of the patient. Typically, such catheters have been provided wlth a single lumen for delivering the chemical. If it is desired to deliver a second chemical to the same site, or even ~to a second ~site, the lumen in the cathete~ for~ ~-delivering the first chemical must be flushed.clear of the first chemical before the~ second chemical can be delivered. This has~been found to~be undesirable in~many s~ituations;,:~ par~icularly because :it is~ difficult to control:~the:~amount of chemical which is d~eli:vered to the ~:: 15: patient:~site.~: In addition,:an undue~amount o~ time is ~:
~: ~required for delivering the ~wo chemicals to the site. `~
: There is therefore;a need for a new and improved catheter .-which can be used:for~d~liv~ring a~-plur~lity of chemicals.
In~general,~ it is an o~iect of ~he present in~ention ::;
20 to provide a catheter~ wi~h~ a retractable cannula~for ~
delivering a plurality of chemicals. ~ ~ ~:
nother object of the invention is to provide a catheter of the above charac~er in which it s necessary --:: ::
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W093/25263 ~ 1 3 1 1 ~ ~ PCT/US93/05060 _ to flush one chemical from the catheter before ~he next chemical is delivered by the catheter.
Another object of the invention is to provide a catheter of the above character in which thére is a minimum of mixing of the chemicals which are delivered.
Additional objects and features of the invention will appear from the following description in which the preferred embodiments are set forth in conjunction with the accompanying drawings.
Figure 1 is a side elevational view of a catheter with a retractable cannula for delivering a plurality of chemicals incorporating the present invention in conjunction with a control console utilizPd therewith.
Figure 2 is an enlarged view partially in cross-section of the distal extremity of the catheter shown in Figure l with the cannula ~eing in a retracted position.
Figure 3 is a cross-sec~ional view taken along the line 3-3 of Figure 2.
Figure 4 is a cross-sectional view similar to that shown in Figure 2 but showing the cannula in an extended position.
Figure 5 is a cross-sectional view taken along the line 5-5 of Figure 4.
In general, the catheter with a retractable cannula for delivering a plurality of chemicals is comprised of a ; flexible elongate member havi~g a centrally disposed lumen and a plurality of circumferentially spaced apart lumens including first and second fIuid passage lumens~ The flexible elongate memher has proximal nd distal extremities. An actuator member is slidably mounted in ~he central lumen~ Neans is disposed within the central ; lumen and engaging the actua~or member for moving the actuator member between extended and retracted positions.
A tool having a distal extremity is carried by the actuator m~mber and has a flow passage therein extending through the distal;extremity. First and second fittings WZ~93~25263 2 1 3 7 1 5 ~ PZCT/US93/05~l .

are secured tZ_ZZ the proximal extre~ity of the flexibleelongate member and are in communication with the first and second fluid passage lumens. Cooperative means is carried by the tool and the distal extremity of the flexible e~ongate member for supplying fluid from said first and second fluid passag~ lumens to the flow passage in thZZ tool when the tool has been advanced to an extended pZ~sition.
More particularly, the catheter with a retractable 10Z cannula for delivering a plurality of chemicals is shown in Figures 1 through 5 of the drawings and consists of a catheter ~1 which is adapted to be connected to a control console 12~ The catheter 11 consists of a fl~xible elongate member 13 formed of a suitable material such as plastic which is provided with proximal and distal extremities 14 and 16. The flexible Zelongate member is : provided with a central lumen 17 and a plurality of circum~erentially spaced apart lumens 18-25 which include at least first and second f luid passage lumens. Thus, as shown~ lumens 21 and 25 are fluid passage lumens and are disposed diametrically of the flexible elongate membZer .
: An actuator mZl~mber 31 is clidably mcîZunted in the central lumen 17 at the distal extremity 16 of the flexible elongate member 13.
: 25 The actuator member 31 consists of a cylindrical or , .
- tubular rod 32 which has circular disks 33 and 34 mounted :
: on the proximal:and distal extremities of the rod 32. The ~ .
tube 3~ is~provided with a bore 35 that extends axially ~; thereof. :The disk 34 is foZrmed inte~Zgral with a tool 36 which i~ the form of a circular cannula which is provided - ~ ~, Z ~ , , with an inclined:cutting edge 37. -:
Coopera~ive means ;is carried by the tool and the i-dist 1 extrPmity of the: flexible Plongate member 13 for ~upplying fluid f~om the first and second fluid passage 35 ~lumens 21 and 25 to flow passa~e 38 providPd in the.
: cannula or tool 3~ and~ ext~nding thr~ugh the distal ~:
extremity of the same. ~This means includes an annular ~

W093/25263 PCT/US93/05~0 -21371~

recess 39 in the tool 36 which has a plurality of circumferentially space apart~ radially extending holes 41 extending from the annular recess 39 into the passage 38.
The annular recess is adapted to be moved into registration with holes 42 and 43 provided in the flexible elongate member 13 and extending from the fluid passage lumens 21 and 25, respectively. M~ans is provided for supplying a fluid such as a liquid chemical to the fluid passage lumens 21 and 25, and consists of tubular members lQ 46 and 47 which have flow passages therein in communication with the fluid passage lumens 21 and 25, respectively. Luer-type fittings 48 and 49 are mounted on the proximal extremities of the t~bular members 46 and 47 which are adapted to be connected to syringes 51 and 52 carrying the fluid, as for example the liquid chemicals that are to be used.:
: Means is provided within the central lumen 17 and ~ ~engaging the actuator member 31 for mo~ing the actuator :~ member 31 between extended and retracted positions. The retracted position is determined by an annular stop 54 which is secured in the lumen 17 by suita~le means such as an adhesive.- Such means can be in the form of first and second helical springs 56 and 57 formed of a shape memory material such as Nitinol, which are coaxially disposed on the rod 32 with the proximal end of the spring 56 engaging th~ disk 33 and the distal extremity an annular member 59 : pro~ided within the centra} lumen 17 and secured to the : wall forming the centr l lumen by suitable means such as an adhesive. The other or second helical spring 57 has 3Q its proximal extremity engaging the annular membe~ 59 and his its distal extremity engaging the disk 34.
Means is provided for supplying eleGtrical energy to the:springs 56 and 57 and consists of a conduct~r 6 extending through the central lum2n 17 and extending into ~the bore 35 and t~rough a hole 62 in the tuhular member 32 : ~and connected to the~proximal extremity of the spring 56 ~ as shown in Figure 2. Slmilarly, ano~her conductor 63 ;~093/25~63 ~ 1 3 7 1 S ~ ~CT/US93/05060 extends through the central lumen 17 and the bore 35 and is connected to the distal extremity of the spring 57 through a hole 64 in the tubular mPmber 32. The proximal extremity of the spring 57 is connected by a cross link 65 extending through a hole (not shown) in the annular member 59 to the distal extremity of the spring 56. The cross : link 65 is connected to a common return conductor 66 through a hole 6~. The common return conductor 66 extends through the lumen 21. The conductors 61 and 63 are provided with coil portions 61a and 63a to accommodate rectilinear movement of the actuator member 31.
: The conductors 61 and 63 and the common return conduotor 66 are connected at the prsximal extremity of the flexible elongate:member ~4 into a cab~e 71 which is connected to: a connector 72. The connector 72 is connected~to a mating connec~r 73 which is connected by a cable 74 to:the control console 12. The control console is~provided with means for supplying energy to the cable :~ 74 under the contrQl of a slide mechanism 76 movable upwardly and: downwardly for: forward and reverse movement of the a~ctuator mem~er 31. The control console~ is the type disclosed ~in co-pending application Serial No.`07/893,7~:0, filed June 5, :1992, (A-55929/HCH~.~ The :: control consQle is pro~ided with an on-off switch 77 and .
an~indicator lamp 78 in the ~orm of a }ight emitting dlode to indicat~:when the power is turned on.~ ~:
In orde~ ~o ma~e it possible to steer:the distal extremity:~16 of~ the ;ca~heter 11, means of the type :~
isclosed in co-pending application Serial No.~ 07/753,~58, i-.
filed~Nove~ber 18, 1991, is provided. As disclosed thereîn, such steering~means ~an consist of ~irst, second : `and thlrd~wires or~elongate elements 81, 82 and ~3 ~ormed of a material:~having;a~negative coefficient of Qx~ansior.
: : such as Flexinol~supplied by Toki of Japan. These 35~ elongat:e elements 81, 82 and 83 are disposed in ~he lumens 19, 2~ and 24, and are offset approximately 120:with respect to each other. When more than three o~ such - ~

WO93/?5263 PCT/US93/05060 -2 1 3 7 1.3 3 elongate elements are provided, they would be offset ~y angles of less than 120. These elongate elements are connected to conductors which extend to the proximal extremity of the flexible elongate element through the lumens 19, 22 and 24, and are connect~.d into the cable 71 and-are connected to the control console 12. The distal extremities of the elongate elements 81, 82 and 83 are interconnected and are connected to the return conductor 66, which also extPnds into the cable 77 and is ronnected to the control console. The control console includes a joystick 9} which is pivotally movable through a cone extending through 360 and is used for selec~ively applying energy to the elements 81, 82 and 83 to cause bending or steering of the distal extremity of the catheter 11 in a manner descri~ed in co-pending application Serial No~ 07/793,858, filed November 18, 1991.
A catheter constructed in accordance with the present invention can have a length ranging from 150 to 200 cm.
It can have an outside diameter ranging from .030 inches to .120 inches. The cannula 36 can be in the form of a : hypo tube which has been beveled to create the cutting edge 37. The hypo tube can have an outside diameter of a suitable si~e such as .015 inches.
Operatlon and use of the catheter with a retractable :
: :: cannula for delivering~a plurality o~ chemicals may now be i briefly described as follows. Let :is ~e assumed that a mapping and ablation procedura is underway wit~ respect to the heart of~ a ~patient~ with ~he apparatus disclosed in ~30 co pendin~ application Serial ~o. 07/656,764~ filed February: 15 J 199~ . Let is be assumed that mapping has occurred and that it is desired to create a chemical : ablation Q~ a portion of the myocardium to destroy ~: aber~ant paths in the myocardium to elimina~e arrhythmias 35 ~in the heart~ of the pat~ent. The catheter 11 of the present invention is inserted into the apparatu5 and is ad~anced into the appropriate chamber of the h~art~ as for :

iW093/2~263 ~ 1 3 7 1 ~ ~ PCT/USg3/05~0 .:

example the left ventricle. This can be accomplished bythe physician pushing on the proximal extremity of the catheter and causing the same to be advanced. In order to direct the distal extremity of the catheter appropriately, the surgeon can operate the joystick 91 to steer the distal extremity into the desired position as described in said co-pending application Serial No. 07/793,858, filed Nove~ber 15, 1991.
The distal extremities of the fluid passage lumens 21 and 25 are closed by plugs 96 and 97 of a suitable plastic so that fluid cannot flow from those fluid passage lumens : : 2~1 and 25 t~rough the dis~al extremity of the flexible elongate member 13. In order to prevent blood and other liquids from~enteriny into the c~nnula 36 when it is in a retracted position and co~sists of a circular disk formed of a ~lPxible material, as for examp:le an elastomeric.
The disk 98 is provided with a slit 99 through which the cannula 36 can extend.
fter the distal e~tremity of the catheter 11 has been~ advanced so that it is in contact with the ; myocardium~ the slider mechanism 76 can be operated to cause electrical energy to be supplied to the spring 57 to cause .it to expand and t~ urge the cannula 36 distally : throu~h the:slit 99 in the disk seal 98 to cause it to :25 punctu~e~the myocardium wlth the knife edge ~37 of the cannula. ~s the cannula 36 is moved forwardly, the : annular recess is moved into registration with the holes 42 ~and 43 whi h are in communication with the fluid passage lumens 21 and 25. As soon as th~s occurs~, a : ~ 30: des~red::chemical can.be introduced by the use of syringe 51 into the tukular member 46 and into the f luid passage lumen 21 to cause it ~low through the lumen 21 to the di~tal~extremity of the catheter and then to pass through the hole: 4~ and thus into the annular recess 39 and 35 `through the holes 4~1~ in the cannula and through the : : passage 78 proYided in ~he cannula into ~he myocardium~

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W093/25~63 PCT/US93/05~0,--2 1 3 7 1 5 3 --8-- !

This procedure is continued until the desired amount of chemical has been dispensed from the syringe 51.
Now let it be assumed that it is desired to dispenSe another chemical from the catheter. This can be readily accomplished by pIacing the chemical in the syringe 52 and ;operating the syringe the cause the chemical in the form of a liquid to be introduced through the tubular member 47 1nto the fluid passage lumen 25, and thence through the hole 4~ into the annular recess 39 and through the holes l~ 41 in the cannula 36 and through the passage 38, to ayain be disposed in the myocardium. It is easy to ascertain when registration has been achieved between the annular recess 39 and the holes 42 and 43 because this information will be communicate~ through the pressure column generated in the fluid passage lumens ~1 and 25 as the liquid is eing introduced into the lumens by syringes 51 and 52.
If the ~annular recess was not in registration with the passages 42 and 43 it wouId not be possible to introduce the liquid through the catheter and this would be readily apparen~ from the physician operating the syringes 51 and ~ 52.
:: ~: Thus it~ can be seen that a plurality of chemicals and, in particular, two, as described herein, can be introduced into the myocardium without the necessity of flushing out ~he~chemical which is p~ovi~ed in the other passage 21. Also it can be~seen that there is very little intermixing of the ~two cheml~als which have been introduced~in the~ catheter itself. The com~on path ; travelled is basically` ~he passage 38 provided in the ~ 30 cannula 36. ~As ~oon as the desired amounts and types of ; ~~chemicals have been in~roduced into tne myocardium, the cannulà~ 36 can be retracted by operating the slider mechanism 76~to the reverse position to ause energization of ths spring 56 to rause it to retract the actuator member 31. Th~s is;caused by the expansion of the spring 56. The catheter can then be withdrawn in a conventional manner. ~ ~

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.~ W093/25263 2 1 3 7 1 5 3 PCT/US93/05~
''; ...' ~9_ From the foregoing it can be seen that a cannul~ has been provided which can be extended and retracted or mo~ed forward and rearward without the necessity of pull wires and the like. This makes it possible to kPep the distal extremity of the ca heter relatively flexible while not making it unduly stiff b~' the use of pull wires.
In addition, it is possible to provide a catheter of the above character in which it is possible to deliver two different chemicals ;with a minimum amount of mixing between the two, and makes it possible to keep the chemicals separated until the approximately last one-quarter inch of the catheter t and also it is possible to deliver one chemical and then another without having to flush the catheter and without the necessity of mixing the two chemicals in the catheter over an extended length of ~ the catheter.
: ~ It is easy to ascertain when registration has been :~ hieved between the annular recess 39 and the holes 42 : and 43 because this information will be communicated through the pressure column generated in the fluid passage lum~ns 21 and 25 as the liquid is being introduced into : ; the lumens~ by the syringes 51 and 52. If the annular recess was not:in registratioh with the passages 42 and 43 : it would n~t be possible to introduce the liquid through the cathe~er and this would be readily apparent from the ~: physician operating the syringes 51 and 52.
Thus it can be seen that there has been provided a catheter: with a retractable cannula which makes it possibIe to deliver a plurality of chemicals to accomplish ablation or to deliver chemicals to tumor sites subcutaneou~ly wi~hout the necessity of in~ading the tumor ~si~e with an~external needle.
it is desired to deliver more than two chemicals additional helical springs form2d of a shape memory alloy 35 ~can be provided on the~:actuator member 31 to provide : ~: additional positions for the actuator member 31 to move the: cannula 36 into~: regi tration with anoth~r hole or W093/25263 PCT/~S93/0506~
213~153 holes ~not shown) in communication with other fluid passage lumens (not shown) provided on th~ flexible elongate member 13. ~

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Claims (7)

WHAT IS CLAIMED IS:

1. A catheter with a retractable cannula for delivering a plurality of chemicals comprising, a flexible elongate member having a centrally disposed lumen and a plurality of circumferentially spaced apart lumens including first and second fluid passage lumens, said flexible elongate member having proximal and distal extremities, an actuator member slidably mounted in the centrally disposed lumen, means disposed within the centrally disposed lumen and engaging the actuator member for moving the actuator member between extended and retracted positions with respect to the flexible elongate member, a tool having a distal extremity carried by the actuator member and having a flow passage therein extending through the distal extremity of the tool, first and second syringes secured to the proximal extremity of the flexible elongate member and having passages therein in communication with the first and second fluid passage lumens in the flexible elongate element, cooperative means carried by the tool on the distal extremity of the flexible elongate member for supplying fluid from said first and second fluid passage lumens to the flow passage in the tool when the tool has been advanced to an extended position.

2. A catheter as in Claim 1 wherein said cooperative means includes an annular recess formed in the tool, holes formed in the annular recess extending into the flow passage in the tool, the holes in the distal extremity of the flexible elongate member in communication with the fluid flow passages and opening into the annular recess when the tool is in an extended position.

3. A catheter as in Claim 1 wherein said tool is in the form of a cannula having a cutting edge.

4. A catheter as in Claim 1 whereby said means for moving the actuator member includes first and second helical springs having a negative coefficient of expansion and means for selectively energizing said first and second helical springs whereby when the first spring is energized, the actuator member is moved into an extended position, and when the second spring is actuated, the actuator member is moved to a retracted position.

5. A catheter as in Claim 1 further including means for steering the distal extremity of the catheter.

6. A catheter as in Claim 5 wherein said means for steering includes first, second and third elongate elements disposed within the circumferentially spaced apart lumens spaced approximately 120° apart and means for selectively supplying energy to the first, second and third elongate elements to cause bending movement of the distal extremity of the catheter to thereby permit steering of the same.

7. A catheter as in Claim 4 wherein said actuator member is in the form of a cylindrical rod having proximal and distal extremities and disks secured to the proximal and distal extremities wherein the first and second springs are coaxially mounted on the rod between said disks together with an annular member disposed within the central lumen and secured to the distal extremity of the flexible elongate member, the distal extremity of the first spring engaging the annular member, the proximal extremity of the second spring also engaging the annular member.