CA2098246C - Catheter and method of use thereof - Google Patents

Catheter and method of use thereof

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Publication number
CA2098246C
CA2098246C CA 2098246 CA2098246A CA2098246C CA 2098246 C CA2098246 C CA 2098246C CA 2098246 CA2098246 CA 2098246 CA 2098246 A CA2098246 A CA 2098246A CA 2098246 C CA2098246 C CA 2098246C
Authority
CA
Canada
Prior art keywords
housing
shear
catheter
opening
means
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
CA 2098246
Other languages
French (fr)
Other versions
CA2098246A1 (en
Inventor
Alexander George Halliburton
Original Assignee
Alexander George Halliburton
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Filing date
Publication date
Application filed by Alexander George Halliburton filed Critical Alexander George Halliburton
Priority to CA 2098246 priority Critical patent/CA2098246C/en
Publication of CA2098246A1 publication Critical patent/CA2098246A1/en
Application granted granted Critical
Publication of CA2098246C publication Critical patent/CA2098246C/en
Anticipated expiration legal-status Critical
Application status is Expired - Fee Related legal-status Critical

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Classifications

    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/32Surgical cutting instruments
    • A61B17/3205Excision instruments
    • A61B17/3207Atherectomy devices working by cutting or abrading; Similar devices specially adapted for non-vascular obstructions
    • A61B17/320783Atherectomy devices working by cutting or abrading; Similar devices specially adapted for non-vascular obstructions through side-hole, e.g. sliding or rotating cutter inside catheter
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/32Surgical cutting instruments
    • A61B17/3205Excision instruments
    • A61B17/3207Atherectomy devices working by cutting or abrading; Similar devices specially adapted for non-vascular obstructions
    • A61B17/32075Pullback cutting; combined forward and pullback cutting, e.g. with cutters at both sides of the plaque
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B2017/00535Surgical instruments, devices or methods, e.g. tourniquets pneumatically or hydraulically operated
    • A61B2017/00539Surgical instruments, devices or methods, e.g. tourniquets pneumatically or hydraulically operated hydraulically
    • AHUMAN NECESSITIES
    • A61MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61BDIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/22Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for
    • A61B2017/22051Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for with an inflatable part, e.g. balloon, for positioning, blocking, or immobilisation
    • A61B2017/22055Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for with an inflatable part, e.g. balloon, for positioning, blocking, or immobilisation with three or more balloons

Abstract

An endarterectomy catheter and method for removing obstructions from an artery comprises a cylindrical, oval, kidney shaped or other shape housing, the housing having a opening inside which a primary shear is movable. The primary shear is razor sharp and cylindrical or other shaped with a smooth or serrated or threaded finish on the inner diameter and movable by means of a firing wire connected by an adapter to a trigger mechanism which moves the primary shear backward and forward within the housing to excise encapsulate and store obstructions that protrude into the opening. The primary shear can also be movedby an electric wire and solenoid, hydraulic system or other means. A guide wire positions the catheter in an artery fallopian tube or other lumen and an inflatable saline anchor or anchors stabilize the catheter against the obstruction to execute a precise cut.

Description

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CATHETER AND METHOD OF USE THEREOF

FIELD OF THE INVENTION

.
!' This invention is directed to cdllleler~ and to a method of excisi.,g obstructions from body channelc. In particular, the invention is directed to a catlleter and method and may be used in many other arp'-~~tions, like fallopian tubes, to ''' ; ~ ~' remove obstructions. -BACKGROUND OF THE INVENTION

An endal lt:r~,tu, ll~ or atherectullly cdthel~r is a device that is il Ise, tedin an artery to remove plaque from the walls of the arteries. This helps to dec(ease - ;~
the risk of heart attacks. In medical terms, an endall~r~-,tu,.-~ cdtl._tur is a device used for the Illechan'~-' recanalkation of occ~uded arteries. Occ~ ons of the ' vascular lumen may result from atherosclerotic lesions in human coronary arteries - ' ~ ~
resulting in unstable angina and eventual myc,cdldial il~ .1ion. - ':

Several dthelt:~,tu~ A o-dtl,_t~,r~ have been deYeloped but all are relatively co~ ted and eA"ensive devices. The majority of these devioes employ a rotating action to remove obstructions. '-.
Simpson, UnHed States patent no. 4,781,186, des~-iLes a double cl.d..lber~d catheter wHh a rotating cutting blade. The distal end of the cdtll_t~,r consists of a solid cylindrical blade in a longitudinal housing wHh a longitudinal window over a third of Hs circumference. The window is on one side and a balloon20 is on the other side of the cdtheter. The housing and the rotating blade are made of stainless steel. The blade is attached to a torque cable in one of the odtll_tor ch~ t~l:~. This cha,-lbar is also used to inject fluid or colltnd~t media into the artery. The other cl-a..lber is used for balloon inflation. A short terminal fixed guidewireassists inposHioning thewindowtowardsthe dtl-e-.~ ' r.tic lesion. The cutting blade is then activated by a hand held motor at 2,000 rpm and the blade is -rotated against the lesion. Excised plaque is trapped inside the catheter A
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separate ~I~echanish~ is used for balloon inflation. Other related patents for the Simpson ~II,erector"y ~U,ebr are European a~plica~ion 352,872, United States patents 4,771,774; 4,669,649; and 4,616,648.

Auth, United States patent no. 4,445,509 des~riLes a catl,ebr having 5 a rotating abr~.sh~e burr that can be advanced over a movable guide wire. The burr rotates at 150,000 rpm or higher and is driven by a cGr."~.~ssed air turbine. The ~ -turbine also pumps a saline solution to cool the fast moving parts. ~-~

Theratek ll,t~,r..ational of Miami, Florida, provides a single lumen flexible polyu~tl,ane ~tl,_hr (also called the Kensey dtl,ert:~,ton,~ catl,~t~r), having a rotating metallic cam at the distal end which is driven at 100,000 rpm to emulsify the ta,geh3d lesion.

Ultramed, Inc. of San Diego, Califomia, pruiides a transluminal e.<t,d~;tion enda,ter~-,h"n~ catheter having a rotating steel cutting blade. The blade - --rotates at high speed, 750 rpm, to excise the ldry_t~,d lesion. A vacuum is used ~ -to retrieve the debris from the lesion.

SUMMARY OF THE INVENTION

The inventor has provided a simplified cathebr that does not require hbh speed rotating blades or drills, and a method of excising obstructions from an artery that may be stored in a reservoir and removed from the body. The catheterof the present invention has further been found to bs generally useful in removal of obstructions from body channel~ including arteries, fallopian tubes and lumen. The cathebr of the present invention mechal ~ally removes obstructions by means of the shea.i"g action of a blade or between a blade and the shar~ned edge of the housing. Thus in one embodiment, there is provided a cathebr for excising obstructions from within a body channel comprising: ~ ' a housing adapted for entry into the channel, the housing having an opening ''''' 2~982~
i~ - 3 -for accepti"g an obstruction;
a primary shear ~i~posed within the housing and moveable across the - openlng;
an urging means conneu~3d to the primary shear and oper ~'~ from outside 5 the body channel for urging movement of the shear in the housing and across the opening to create a guillotine action;
and, means for locating the housing in the channel.

In another embodiment there is pruii;led a cdtl,_t.,r for c ~ ,9~ 10 obstructions from within a body channel co",~risi.,g.
a housing adapted for entry into the channel, the housing having a nose end, a rearward end continuous with a communicating tube for allowing communication with the housing from outside of the body channel and an opening ll,er~Le~t ~een for accepting an obstruction;
a cylindrical substantially hollow primary shear d;~posed within the housing and moveable across the opening;
an urging means conna~,teJ to the primary shear and operable from outside the body channel for urging the snear to move within the housing and across the opening to create a guillotine action, the urging means being in the form of a tube 20 connected about a radius of the shear and being cP .posed within the communicating tube; and, means for locating the housing in the channel~

An inflatable anchor may be atlached to the housing to maintain the haousing in position in the body channel~ The anchor may consist of any number 25 of fluid fillable bladders to secure the catheter against the obstacle to produce a precise cut, a smooth finish close to artery wall, while locating the housing within the artery~

The enda,tbre-,t~,l"j catheter may further include means for collecting - 20982~6 i r,ag,l,erlts of an obstruction that has been cut by the primary shear. Those means may include a packing stub at the forward end and a hollow tube behind the shearto act as a ~ 'le 'ian reservoir and as an urging means.
: . .
The cdtl,~t~,r housing is preF~,rably substantially cylindrical and the 5 primary shear is pr~fer~l:ly hollow, substantially cylindrical and snugly ftted within the housing to create, along with the edge of the opening, a pair of opposil,g sheari"g surfaces.

In a further embodiment, the enda, t~r~..to", J, cdtl ,~t~,r housing includes an inner tubular section extending from the forward end to the reanNard end, andan outer tubular section extending from the forward end to the rearward end, theinner tubular section being fitted within the outer tubular section, and the primary shear being d;~posed b t _en the inner tubular section and the outer tubular section.

In a still further embodiment, the opening extends fully around the housing.

In further embodiments, the forward edge of the opening, or all of the opening, may have a sh~r~ anad edge to assist in the guillotine action of the primary shear, the shear can be operated by the same firing ")echani_." or spring action, hollow tube which would permit storage of plaque in a type of reservoir, the housing may be flexibb to allow for ease of positioning of the housing and the housing may be pr~vlded with openings in its forward and rearward ends to allow body fluids to flow through the cathebr while it is in operation.

In a broad aspect of the present invention there is provided a cdthoter sysbm for excising obstructions from within a body channel comprising:
2S a~housing adapted for entry into the channel, the housing having an opening for accepting an obstruction;

:
5 ~a~

a primary shear ~; posed within the housing and moveable àcross the opening;
an communicating rneans connected to the primary shear and oper - le from outside the body channel for urging the shear to move within the housing and across 5 the opening to create a guillotine action;
a ll iggeri"g means for l,iggering the communicating means to urge the shear movement from a location o ,.t~r,.al of the body channel; and means for locating the housing in the channel.

In one embodiment of the method of the invention there is provid10 a method of excising an obstruction from a body channel the method coi"priai.,g:
locating a housing within the body channel a~jacer,l an obstruction the housing having an opening for accepti"g an obstruction and a shear moveable across the opening;
positioning the housing such that the obstruction protrudes into the opening~5 of the housing;
urging the shear across the opening to excise at least part of the obstruction with a guilbtine action; and removing the housing from the body channel.

The adv_r,tdges of using the cdth_ter over the prior art devices 20 include: the primary cutting edge cleaves the obstruction cleanly from the channel wall and entraps the debris withir. the serrated finish of the insWe diameter of the primary shear; there is no high speed rotating object in the cavity that can otherwise da",age the cavity; there is no heat build up through operation of the cutting edge;
no cooling i"echanisri, Is required; no vacuum is required to remove the Fldg",ents 25 of the obstructlon since all tissue may be ~ ct~d in tube reservoir; ,~n,oval of tissue from the reservoir may be accomplished through syphoning by syringe; and,no motor or complex support system is required.

~ .. . .. , . ... ~. .. . .. ~ . -. ~

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BRIEF DESCRIPTION OF THE DRAWINGS ' There will now be descril,ed pr~,F~,r,ed embodiments of the invention, ,~- with ,ef~rence to the drawings, by way of illustration, in which like numerals denote . Iike elel"eril~ and in which: -i~
Figure 1 is a per~pe-,ti~e of an embodiment of a cdtl,et~r according to the invention with a cable conne-Aion to the catl,_t~,r, and includes firing jl ",echan;_.--.

Figure 2A is a longitudinal section of one embodiment of a housing according to the invention;

Figure 2B is an exploded longitudinal section of the housing of Fig. 2A;

Figure 3A is a longitudinal section of another embodiment of a housing according tothe invention;
-.-... ~ . ...
Figure 3B is a section along the line 3B - 3B of Fig. 3A;
.
Figure 4A is a longitudinal section of another embodiment of a housing ~ .
according to the invention;

Figure 4B is an exploded longitudinal section of the housing of Fig. 4B;

Figure 5A is a longitudinal section of another embodiment of a housing according to the invention;

Figure 6A is a detailed longitudinal section of another embodiment of a housing according tothe invention;

:: . ., :

:

~ - 7 ~982 ~

Figure 6B is a longitudinal section through a shear having a base -clamp to accor"",odate alldcl r"ent to the firing wire;
' :',.~,'"
Figure 7 is a detailed longitudinal section of another embodiment of ~ -a housing according to the invention;

Figure 8A is a longitudinal section of embodiments and cor,~sponding ~ '~
cross-se~tions of an i, 'a~a~' saline anchor, which are to be used with other embodiments of the invention;
. ~
Figure 8B is a series of plan views of embodiments of i" '~ ~ ~le saline anchor;
, .
Figure 9 is a cross-section of an extruded tube as is also shown in longitudinal section attached to a housing;

Figure 10 is a longitudinal section of an embodiment of a cdU,et~ r adapter according to the invention;

Figure 11 is a longitudinal section of an embodiment of a snap adapter - ~ -asse.,l~ly cGr"pri~;"g of many parts according to the invention;

Figure 12 is a longitudinal section of an embodiment of a firing trigger ",ecl,an:_.,. according to the invention; and, Figure 13 is a longitudinal section of an embodiment of the enda,brectul,.J c~4tl,ot~r ",echan ~ of encapsulation according to the inventiQn.

DESCRIPTION OF l~Kt~tKKtU EMBODIMENTS

In this patent, a shear is the cutting means or blade used to cut ~09~2~

through an obstruction using a slicing action referred to as a guillotine action.

While o~en in this patent the use of the present invention is taught for : -use with removal of obstructions from arteries, generally ~l~atelial may be removed from any body channel such as an artery, fallopian tube or lumen, wh~tl,er it be a 5 fatty, fibrous or calcified tissue dep~s ' ~n (known for eAdlllpla as ~.lher.~ r~tiG
plaque, atl,ercr"a or lesion), which wi!l be referred to as the obstruction.

A des~ tion of ",athGds and appardtus currently used for the ,emoval of obstructions may be found in the 1 extbook of Inter~ ~tional Cardiology, Edited by E. J. Topol, Saunders, Philadelphia, 1990. -~. - ~ .
P~-,fur.ed embodiments of the invention will now be des~;,il,ed.

l~f .. i-.g to Fig. 1, there is shown a perspective view of a cathebr '~
according to the invention. A housing 110, including an opening 120 and primary shear or blade 130, is connected to urging means such as cable or firing wire 104 for moving the primary shear 130 in the housing 110 across the opening 120.
Means such as guide wire 102 for locating the housing 110 in an artery may pass ; ' through the housing 110, or in an altemative embodiment be transferred through alumen of an extruded tube. Both the guide wire 102 and cable 104 are capable of sliding within at least one sleeve 106. The opening 120 is p~ferdbly oval being slightly elongabd in the longHudinal direction, and should be sufficient!y large to receive at least part and preferably all of an obstruction. The cable or firing wire 104 exHs the sleeve 106 at port 103 and is preferably operated manually from outside the artery by trigger 108 to move the primary shear 130 r~ ~cally backward and forward within the housing 110 across the opening 120. The guide wire 102~ exits the sleeve 106 at port 105. An port 100 for injecting material into or withdrawing material from the housing or artery along the sleeve is also p,uJided.

' ;' ' :'- ' 2 ~
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rwelve embodiments of the invention will be desc,iL.ed here with rence to Figs. 2A, 2B, 3A, 3B, 4A, 4B, 5, 6A, 6B, 7, 8A, 8B, 9, 10, 11, 12 and 13. In each case, but Figures 6, 7, 9, 11, 12 and 13 the same guide wire 102 is used, logell,er with sleeve 106, trigger 108 and ports 100, 103 and 105. The main , ' 'r~:r~nce tet ve~n the embodiments shown in these figures is the construction of the housing, the primary shear and the opening and these will be descril.ed in some detail. Embodiments of an ancho,ing system, extruded tubing and l,igge,i"g n,echanic.n will also be desc,il,ed. A further embodiment using an ebctlical wire and s~' n~ :l a"dngeillenl or hydraulic actuation means forthe shear, has not been shown in any ofthe figures.

An embodiment of the catheter as shown in Figs. 2A and 2B col"prises housing 210 including a forward nose end 212 and a rearward end conn~,~d by a tubular section 216. The tubular section 216 defines a substantially oval opening 220. Apertures 242 and 244 in the forward and rearward ends r~s~s ~_ly allow blood to pass through the housing 210. Guide wire 102 passes through openings 248 in the housing 210.

The primary shear 230 is hollow and subsbntially cylindrical with sides 232 and a cylindrical hollow ground cutting edge 234, (ie. "Slide Fit"). The primary shear 230 is adapted to fit snugly within the housing 210, and is movable backwards and forwards within the housing 210 across the opening 220 under control of the hring wire 104, which is a~ched by any suitable means to the base portion 236 ofthe primary shear 230. At the forward extent of the primary shear 230 (upon movement of the primary shear 230 within the housing 210), the edge 234 is preferabb sheathed within the housing 210 beneath a lip 224, and the opening 220is complebb blocked by the cylindrical sides 232 of the primary shear 230. The primary shear 230 may be viewed as a circular blade that has been adapted to theshape of the housing, and sheathed within the housing, so that it is substantially only mo~vable r~;l,rocalîy across the opening, thus not requiring any rotary motion to excise the obstruction. The hollow, cylindrical inbrior walls 232 of the shear 230 . ~ . . . , .. . ,, .. , . , ~ . . . . . .

, . . . . . .
. ;;~.. ~ ., . , , . . ~

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,.., have a smooth or preferdLly sen dled Ihreaded or roughened surface to snag debris which constitutes a means for collecting fi~yln~nt6 of an obstruction. Thus in operdtion the excised part of the obstruction is enç~rs~ d facilitating removal of the excised part of the obstruction from the artery or ~ ng multiple cuts where 5 debris passes along the hollow shear 230 to a hollo~h tube reservoir formed in the housing 210 or toward the base 236 of the hollow shear 230.

The cutting edge 234 of the primary shear 230 is pn F~ r~bly bevelled on the inside only as shown in Figs. 2A and 2B, such that the cutting edge 234 is as close to the inside wall of the tubular section 216 as possible. The bevelled1Q portion of the cutting edge 234 is pr~ardl~ly hollow ground (concave) to render the edge as sharp as possible, though it may be straight. The cutting edge 234 may also be spiked to form a trocar like body wKh a point or spike as des.;,il,ed in more ~ ~
detail in relation to Figs. 3A and 3B such that the point may affK or spear the ; -o~s~stion before piercing and excising it. ~;

The firing wire 104 passes through one of the apertures 244 in the rearward end 214 of the housing 210 and is dttaohed to the shear 230 at p,efe,ably ad~aoerlt the base portion 236. The shear 230 is moved along the housing 210 by ~ ~ -pushing or pulling with the wire 104 through the trigger (not shown). The boundaries of the opening 220 are pr f~ rably sha,l,enad to form a secondaly shear 222 to assist the cutting action of the primary shear 230. The secondary shear 222 assists particularly in holding the Id~ ed obstruction in place while the action of the - :
primary shear 230 is r~spon~;'~le for most of the cutting action. The slide fn of the primary shear 230 within the housing 210 is i"-pG,lanl in c~ti~-g an effective cutting surface at the base of the obstruction close to the wall of the artery.

As shown in Figs. 2A and 2B, an interior lip 226 is formed on the forward nose cone 212 around the circumference of the housing 210 adjacent the - -~
s~condary shear 222~ The inbrior lip 226 and lip 224 pro~/ide a notch 228 into ' . . .:
.

5 ~ . ~
- 1 - . : . ' which the cutting edge 234 of the primary shear 230 fits upon cor"~ l cn of the -shea,i.,g action. The close fit of the notch 228 with the cutting edge 234 helps to ensure that the obstruction is coln; let !y severed from the artery wall. This feature can be i",po,t~nt in the case of some particularly resilient obstructions.
. .
An opening 246 in the rearward end of the primary shear 230 allows blood to flow through the primary shear 230. Screens 252 may be pruJided in the forward and rearward end caps 212 and 214 r~spe- ti~al/ to catch any fidy",er,ts of the obstruction that escape encars~ hn by the hollow tube reservoir in the primary shear 230 or housing. The screens 252 may be secured by lock washers 254. If desired, the lock washers may be omKted and the screens 252 press fnted into place.

R~f~ ..i"g to Figs. 3A and 3B, there is shown a further embodiment of a catheter according to the i".~unt ~ n. The embodiments of Figs. 3A and 3B is -~ -~I.IF!~ to manufacture and thus is not a prefu..~d embodiment. In this embodiment the housing 310 co~ rises a rearward end 314 aforward end 312 an outer tubulaf section 316 and an inner tubular section 318. The inner tubularsection 3~8 is located centrally within the outer tubular section 316 and is hollow to --allow blood to pass through the housing 310. Additionally apertures 342 and 344 in the forward and rearward ends respectively allow blood to pass through the housing 310. Guide wire 102 passes through openings 348 in the forward and rearward ends of the inner tubular section.

Although blood may pa~ through the embodiments of the housing shown, for most applications the cathebr guide wire 102 and cable 104 combination sheathed wKhin one or more plastic sleeves will block the passage of blood during treatment. In such cases, aut~perfusion methods as de~i.iLed at page 454 of the Textbook of Inbrven ~ nal Cardiology. referred to earlier in this patent, may be used to allowhlood to flow during the use of the catheter. In such ~ h~ls, small holes 360 are formed in the sleeve 306 and the blood may pass into along and out of the ... . . . ..... ~ .. ..... , . - . - . . - -... -; . ~. - .- .. - .. ..... ~. . .. .

-- 2 0 9 8 ~

sleeve 306.

The primary shear 330 slides along the inner tubular section 318 and is hollow and substantially cylindrical having sides 332 and base portion 336. The base portion 336 includes small apertures 346 to allow blood to pass through the ~
shear 330 while preventing the pa.csage of excised obstruction. The shear 330 is ~ i manipulated by the wire 104. The outer tubular section 316 defines an opening 320.
The opening 320 is formed similarly to the opening 220. The edge of the opening is sharpened, pr~r rably hollow ground, to form a secondary shear 322 and is e~ nded a~jacent the nose end 312 to form a lip 324.

In this embodiment, a cûr,,pression spring 350 is proii;ied to urge the primary shear 330 forward from the position shown in Fig. 3A to a forward position (not shown, but the equivalent position is shown in ghost outline in Fig. 2A) in which ' ~ ~ ' the cutting edge 334 of the primary shear 330 is sheathed benedtl, lip 324. A ~ I
guillotine action occurs upon ",ul_."e,lt of the primary shear 330 into contact with the secondary shear 322, which will excise any obstruction protruding into the opening. -The primary shear 330 is shd.~,ened in the radial direction to form an -edge 334 for shaa, i"g an obstruction. The cutting edge 334, with ~f~,rence to Figs.
3A and 3B, forms a point or spike 338 in the circ~..,f~ entbl direction. The spike 338 may be formed on both sides of the primary shear 330, so that the spike 338 may be availabb for piercing even upon rotation of the primary shear 330 within the housing 310. If desired, the primary shear 330 and the tubular section 316 may be slotted or keyed (not shown) so that the primary shear 330 is guided linearly along the longitudinal axis of the tubular section 316 and prevented from any rotation. The spring 350 may be operated using the cable 104 and a suitable catch on or near the trlgger 108 for operating the cable 104. The cable 104 may be pulled backward sothat the primary shear 330 moves rearward in the housing 310 to con~,r~,ss the spring 350. The spring 350 may be held in pbce by a suitable catch and the catch .

,, ~'.

- ~09g~4~

~leased when it is desired to excise an obstruction. The catch may be any suitable catch for holding a co"")ressed spring. For exd~ 'g, the catch may be a button on the cable 104 that slips into a recess in the plastic sheath 306 aJjacenl the trigger ~ ;
108 when the trigger 108 is fully pulled back. To release the spring 350, the buffon 5 is pushed in.
.

Figs. 4A and 4B show a further embodiment of the invention, in which housing 410 includes rearward end cap 414, a forward nose cone 412, an outer tubular section 416 and an inner tubular section 418. The outer tubular section 416 is conce.~t,ically located about the inner tubular section 418 and the inner tubular 10 section 418 extends beyond the outer tubular section, thereby forrning an opening 420 that extends fully around the housing 410 between the outer tubular section 416 and the forward nose cone 412. The inner tubular section 418 is pr~,f~irdL.ly hollow to allow for the i..-~e.tion of the guide wire 102 and to allow for the p~ssag~ of blood through the housing 410 during operation of the cdtll~tc.. Apertures 442 and 44415 in the nose cone and rearward ends respectively also allow blood to pass through the housing 410. As with the embodiment shown in Figs. 3A and 3B, autoperfusion lecl.n, ~es may be required to allow blood to pass the sleeve atlached to the catheter.

As shown in Fig. 4A, primary shear 430 is slidably mounted on the 20 inner tubular section 418 and is movable from a first, rearward, position in which the primary shear 430 is fully retracted in the outer tubular section 416 to a second, forward, position shown in ghost outline. In the second position, the cylindrical sides 432 of the primary shear 430 completely block the opening 420 and the cutting edge 434 of the primary shear 43Q is sheathed in the lip 424 of the nose cone 412.

The primary shear 430 is hollow and substantially cylindrical with cylindric~al sides 432 and sharp cuffing edge 434 similar to the cutting edge de~criLed above in relation to Fig. 2A and 2B. The primary shear 430 has one or ~. ..... ,, .. , . ....... .. ,., .,.. ~ . .. . . ........ . . .

.. . - .. . .~ ~ .- - ., .. .. , ,, , . -.

209~2~

more apertures 446 in its base portion 436 to allow blood to pass through the primary shear 430. The openings should pr~f~,rably be sufficiently small to prevent excised parts of the obstruction from entering the blood stream.
~.
The edge of the nose cone 412 aJjacent the opening 420 is pr_f~rably 5 sha",ened to form a secondary shear 422 to assist the guillotine action of theprimary shear 430. The primary shear 430 is operated by the cable 104 which passes through an aperture 444 in the rearward end 414 and connecls to the primary shear 430 a~jacerlt an opening 446 in the shear. The cable 104 in turn is operated by a trigger (not shown) but as described here;.,abo.~. The secondary shear 422 is pr,ferdiJly hollow ground as shown at 462 to create an extlemely sharp cutting edge.

Fig. 5 shows a further embodiment of the invention, in which housing 510 includes a forward nose cone 512, an outer tubular section 516 and an inner tubular section 518. The outertubular section 516 is concert~ically located about the inner tubular section 518 and the inner tubular section 518 extends beyond the outer tubular section, thereby forming an opening 520 that extends fully around the housing 510. The inner tubular section 518 is pr~f_rdi,l~ hollow to allow for the i..~,~icn of the guide wire 102 and to allow for the paCsa.~e of blood through the housing 510 during operation sf the ~dUI- t~,r. As with the embodiment shown in 20 Figs. 3A and 38, autoperfusion t~chr, ~iues may be rquired to allow blood to pass the sleeve attached to the catheter.
':
Primary shear 530 is mounted by a hollow bush on the inner tubular section 518 and is movable from a first, rearward, position in which the primary shear 530 is fuliy retracted in the outer tubular section 516 to a second, forward, position shown in ghost outline in Fig. 5. Hollow bush 561 prevents cocking of the shear 530 during movement along the inner tubular section 518. In the second positbn~ the cylindrkal sldes 532 of the primary shear 530 complebiy block the opening 520 and the cutting edge 534 of the primary shear 530is sheathed in the 209~2~S

lip 524 in the fo~ard nose end 512 of the housing 510.

The primary shear 530 is hollow and substantially cylindrical having cylindrical sides 532 and sharp cutting edge 534 similar to the cutting edge des.;,il,ed above in relation to Fig~ 2A and 2B. The primary shear 530 has one or more apertures 546 as previously descdl ed in base portion 536.

The boundaries of the opening 520 are pr~fe.dbly sha",ened to form a secondary shear 522. The primary shear 530 is ope~ ~ d by the firing wire 104 which connecls to the base portion 536 of primary shear 530. The wire 104 in turn is operated by a trigger ",echan;_m such as in Fig. 12.

The embodiment of Fig. 5 dfflers from those previously des.;,il,ed in that there is no rearward end cap. The housing embodiment desc.il.ed in regards to the prior Figures has been eAlerdèd to be continuous with the sleeve 406.
I~F-cesses 515 are formed in the housing forcrimping connaction between the sleeve and the housing with bush 563. The housing 510 is advanced along the artery by pushing the tube 506. The sleeve 506 may be simply plasbc to allow protection for firing wire tO4 and guide wire 102 or may be modified to braided cable or extruded tubing to enhance the use of the invention. The conbnuous sleeve/housing ar.dnge..,ent allows for more access to the cdth_t~ r during use.

Figure 6A shows a further embodiment of the invention in which housing 610 includes a nose end 612 and a tubular section 616. The housing 610 is adapted at 615 to crimp by bush 663 onto the braided wire or extruded tubing 606. To strengthen the housing, nose cone 612 includes a recess 680 to perrnit asecure crimp between the nose end 612 and the tubular section 616.

The nose cone includes a packing stub 664. The stub 664 acts to push an~d pack the plaque further into the housing once removed. The catheter may be used repeatedly before ,~.r ,ol;ng the plaque. The stub 664 bkes the forrn of a ~982~ ~

,~arv,~ e~tension ofthe nose cone which fitswith the cylindrical shear 630. The opening 620 on the tubular section 616 is enldryed. The cdtl,e~e~s of the present invention may have a choice of firing wire a~ldch"~enl. In Fig. 6B a base clamp is shown for dlld~hl"enl of the firing wire 104 to the shear 630. The base clamp acts to stabilize and prevent cocking of the shear. The force inserted by the firing wire is distributed by the clamp evenly over the circ~""~ nce of the shear. The firing wire 104 may also be simply dtlached to the inside of the shear 630 as shown in Fig. 6A. A hollow bush (not shown) may be welded glued or swaged to the ,earw_r:l end of shear 630 to accept the firing wire 104.
The embodiment of Fig. 6A is co",pri~ed of six parts however the housing can be moulded in i""~r~yn : d plastic which can realistically dec~ase the number of working parts to three. The use of plastic i""~.,ated with excess carbcn or KEVLAR~ allows the embodiment to be reduced to a unitary housing a shear and a firing wire.

Another embodiment shown in Fig. 7 may be called a tube within a tube. A tube 704 allached to shear 730 is acco~.""odated within an outer tube 716 re~lac;ng firing wire 104. The housings of the previously discu~sed embodiments would have to be adapted to a~r"",odate the tube 704. The inner tube 704 may be conn~ ~ ~ to a sho,ttned shear 730 or alternative~y tube 704 may be fitted with a sha",aned tip pref~ rably formed of chrome in place of shear 730. The tube could be adapted to cooperate with the firing n,ecl,an;_." as will be discussed in regards to Fig. 12.

This embodiment allows for simplified manufacturing. The housing 716, nose cone 712 and extruded tubing extending from housing 716 could all be moulded in one operdtion while tube 704 is moulded in another operdtion. In addition, plaque may be pushed into the inner tube 704 by packing stub 764.
'' ; . .
A sho,tened shear as in Fig. 7 allows for more flexibility in the 20932i~

cdU,eler. The use of the embodiment of Fig. 7 allows for improved torqueability and pushability of the catheter housing 710 while in position. Further, with this embodiment a vacuum system may be used ~,~;,ereby a vacuum is applied to the tubing which draws obstructions through the opening, enl anc;.,g the removal of the 5 obstructioil and removes the excised parts up through the tubing.

The primary shears 230, 330, 430, 530, 630 and 730 are prof~,rdbly made of stainless steel or chrome, although hard plastics, formed for example byinjection moulding, may be s ~lisr -itory for cutting some kinds of obstruction. The shar~,ness of the primary shears should be selechd to cut through the hardest 10 obstruction that may be encountered, such as calcified plaque.

The housings 210, 310, 410, 510, 610 and 710 may be made of stainless sbel or suitable plastic, and for some applications may be made of flexible plastic. A flexibie housing is desirable where the Idly~,t~d artery is heavily occluded or tortuous such that it would be dmicult to penetrate and manoeuver around 15 comers with a rigid housing. Suitable plasffcs include high density polyulétl.dne, metl.J4,e.~tane poly.llêr, poly_lhJbne t~,haphthalate, chlortrifluo~o_lhykne andpoly~.l,onate. Plastics such as PLEXIGLASr~, available from Rohm and Haas Co,..~,an) of r~,nn~ yl~_n;d, and DELRIN~ may also be used.

Each of the housings is p,efe.~bly tapered and rounded at its forward 20 end to facilitate i.,sc.tion of the housing into an artery. The ske of the housing should be suKable for insertion into arteries and manoeuvering through them. Thethickness of the housing should be chosen so that it is sufficiently strong to guide the primary shear and allow for inse.~;~n of the housing into an artery, but should not be so thick as to prevent the primary shear from cutting away a .easonable 25 portion (preferably most) of the obstruction. The length of the housing may vary for most applications from 8 - 25 mm and the outside diameter may vary from 2 - 5 mm.
The length of the shear may vary from 2 - 12 mm for most a,c~'k~icns.
Manufacture of the nose cones and tubular ss~l',,ns and their s~hsequent joining ~ ~ 9 ~

logetl ,er may be accomplished by any of several known lechh ~ues cor"n~only used for the manufacture of call,eter:, for medical arF"~~~;cns. A spring useful in the embodiment of Figs. 3A and 3B of an appropri ~t~ size and ~len~tll may be readily co"""er~.ially obtained.

To enhance the functioning of the c.. :h~ters of the present invention~
stabilizing cha,nber~ may be atld~hed to the housing to anchor the cdtl ,~ t~ r in place during use. Figure 8A illustrates an inflatable anchor 872 which may be manufactured from suitable material and may consist of a number of stabilizing cha",ber~ (2 are shown) to position the opening 820 in relation to the obstruction.
10 Such saline anchors 872 may be placed at various pos~tions on the circu", r~nce of the housing although the pref~r,t d location is directly opposit the opening 820.
The pn f~ .,ed embodiment contemplates use of either two four or six sbbilizing cha,)lbe~s 872 as positioned opposite opening 820 according to cross-sectional views taken along X-X and labelled 8Ai 8Aii and 8Aiii ~espe~ti-_ly. These 15 cha~,bar~ may be situated directly before and after the opening 820 as best seen in plan view 8B on the IJ..derside of the catheter housing 810. As shown in Fig. 8B, these ch-d..lbera are pr~rably equally distributed on the u ~-de,~ide of the ~thEter housing where the cross-sections 8Ai 8Aii and 8Aiii relate to sections through X-X
on plan views 8Bi 8Bii and 8Biii respectively. The chd-.lbe,:~ 872 arefilled with a 20 suitable fluid such as air or preferably saline through tubes 874 which continue to extend between chd"lLer:. 872. The saline is injected at a port (not shown) aJJacent the trigger ",echanis.".

The inflation of the bladder~ stabilkes the c~th_t r within the artery to ensure a smooth precise cut. By use of the inflatable anchor on an opposite side25 of the housing to the opening, the opening will be eased against the artery wall forcing the obstruction into the opening, ensuring the re...o~al of the obstruction as close as possible to its base. The equal distribution of multiple chanlber~ allows a uniform pressure against the artery wall, resulting in a smooth excision of the plaque from the artery wall.

~ ~3 9 ~ iJ

Figure 9 illustrates the cdll,eler extruded tube as was desc,i!ved in regards to Fig. 7. The cdthettr extruded tube 979 can be made in various dian,eter~ or shapes to suit each individual catl,eler. The walls of the tube enclose a large central reservoir 977. Formed within the walls are a plurality of lumen 972, 944 and 948 which may accon"~,Gvlate a cGmbi ,alion of hring wire 104, guide wire 102, fluid tubes (not shown), and one, two or three stabilizing wires 976. The inclusion of stabilizing wires along the length of the extruded tube prevents tubular stretch when the trigger ,,,evl,ar,;_.,, is fired. In this way, all of the positive thrust is transmitted to the shear. It is also em/i~,aged that 5~ levted lumen of the extruded tubing may banspo,l other materials such as dye, ll,erdpeutic agents, co?g~ ts and cauterizing agents. The c-dth_t~r extruded tube is dtlacl,ed to the housing by various means, ie. swaging, crimping, cold vulcanking, thermo-welding, while the~r~h.,ed embodiment would use suitable epoxy cement.

The inc~ased strength of the tube offers the ability to move the housing through very small arteries and around tortuous bends in arteries, ~ ng the precise location of the cutting surface longitudinally in an artery. Additionally, the ability to apply a rotational force from the firing ,..ev~l,an;_... to position the cutting surface in the desired radial position in the vessel is offered by the use of a tube. The large reservoir of the tube acts to store excised debris. In addition the 20 extruded tubing allows the guide wire to be e~t~rlv'ed along a side of the housing through a lumen or monorail rather than through the center of the housing.

Figure 10 repr~.se.~ts an embodiment of a cdtll_ter adapter for attacl....ent ~jacent the trigger ...echdn;_r.., allowing an access port to the extruded tubing. The adapter 1000 is connected at the forward end 1005 to a Yjunction, tsuch as a Touhy Borst), and atthe rearward end 1006, to a snap adapbr a55e.~lblf as will be discussed hereinafter in Fig. 11.

The cathebr adapter as shown in Fig. 10 connecls a ~r~ junction to a snap adapter asse."b~f. The ~th ~t~ r adapter can be maintained between the "~' ' ~ ~ 9 2 ~

junction and the snap adapter asse,l,bly in a number of ways. The pref~r,ed allaci"nenl is a ll"eaded end at 1005 for ll,r~aded engage,ner,l of a locking grub screw 1203 (shown in Fig. 11) to attach the snap adapter asser"bly. The pref~r,t;d is formed from plastic. As can be seen in Figure 10, the catl,eter adapter has acentral channel 1003 of varying dia",~ler along its length. The central channel accG",modates tubes or wires, such as the firing wire 104 before entry into the extruded tube. A cdtl,eter adapter i"t~ nded for accG,,,mGddtiùn of the firing wire 104 as shown at 1007, to eliminate kinking of firing wire. Pl~fe~abiy, the adapter is ll,ieadably engaged to the ~r~ junction while a number of grub screws extend through the snap adapter asser"bly to engage recesses 1002.

The ~r~ junction adjacen~ the folward end 1005 may be used for saline in; ~-on into the catl,otur extruded tube as in Fig. 9 which is bar,srer,.ad to the inflatable saline anchor or anchors as in Fig. 8A. Further multiple ~r~ junctions may be utilized for the introduction of further Illéld?eutic agents or dyes for lranspo,l through the extruded tube. Materials that are introduced through the ~r~ junction to the tubing may exit the tubing at any point along Ks length or at the cutting point of the shear. A ~r~ junction could be utilized for introduction of suction line to remove the packed debris from the reservoir of the tubing. Alternatively a ~r~
junction could be used to introduce a wash fluid through the extruded tube to push out or clean packed debris that has been gathered in the r~ser~o;

Figure 11 illustrates a snap adapter asse"lbi-~ 1200. The snap adapter is, in the preferred embodiment, connected between the trigger ",echal,i_." and the catheter adapter leading to the extruded tube. The snap adapter 1200 cor"prises a main body 1204, an adjustable adapter rod 1205, an adapter stud 1211, a guide tube 1207 and a securing point 1209 forthe firing wire 104. The forward end of the main body 1204 forms a recess 1201 to accept the catheter adapter, as in Fig. 10, and thraaded opening 1203 to accept the means to secure the catheter adapter such as~grub screws~ The main body 1204 has a plurality of g,uu~I_s 1202 which allow mating with the firing ",ecl,anisr" as will be discussed in regards to Fig. 12.
: ', 2~82~

The outer surface 1213 of the snap adapter asselnbly can be adapted to provide ahigher friction or gripping surface for exd", 'o by knurling to permit the rotation of the snap adapter body which rotation will be transmitted through the extruded tubing to allow the rotation of the housing. The rotation of the adapter through 360 5 degrees may be accom ' hed without having to repo~,1ion the firing mechani_l".The knurl may be calibrated in degrees or some other means to identify the radial location of the housing.

The main body 1204 forms a recess 1208 to accept the adjustable adapter rod 1205. The adjustable adapter rod 1205 is free to move longitudinallywNhin the snap adapter asser"~ly 1200 but can be locked in place by a grub screwexlended through ll,rt:aded opening 1212. The adjustable adapter rod 1205 is free floating so as to allow for the action of the firing ~"ecl~an;_." and further to allow for ex~,anshn or conba. tion of the firing wire 104 as it moves through the arteries.
Adjustable adapter rod 1205 cor -p-i .as a flange 1240 containing the securing point 1209 of the firing wire 104. In the pf~fe.-ed embodiment the firing wire 104 is secured at the adjustable adapter rod 1205 through engage...enl by grub screws (not shown) extending in from c~FD~ sides the firing wire 104. As shown in Figure 11 the adjustable adapter rod 1205 contains a guide tube 1207 to 20 aceo..,--,odate the firing wire and to prevent the kinking or bending of the firing wir 104. The rearward end of the snap adapter asse.nbly is ll"eaded at 1210 to mate with cap 1206 of the adapter stud 1211. Th,t:aded portion 1210 acts with cap 1206 to provide adjustment forthe adapter stud 1211 allowing forfine adju;.b.,er,ts to the free floating adjustable adapter rod 1205 and thereby adju~t~..er,ts to the length of 25 the firing wire 104. The length of the firing wire determines the range of movement of the shear within the housing. The position of the shear 230 may be debrmined when in use through the use of a fluoroscope. The adapter stud 1211 is snapped into the firing ",echan;_.n providing positive ",echan -' connection between a firing pin of the firing ,..e~har,:_r, and the shear through the firing wire. The e~ ~.entA of 30 the snap adapter as-~el/~bly are preferably plastic.

,. ~ : . ~ . ~. . ............................................. .

. .~.. i , : -.

It is conle,l",lated that the shear ",echa~ ." of the ~dtl,et~ r may be operdtad ",echanAally or hydraulically or by electro-",echal.i-- action (ie. an elect,i~al signal l,iggeri"g a so na ~). In each such case the firing mechan;_n,design would be governed by the need to transmit the appl ~ le signal or force 5 (ie. hydraulic or ele~:t,;cal, etc.) to the shear. For reasons previously ",enlioned the prefar,cd embodiment is a ",echan ~~' trigger ",echan;_.-, for projecting rapid force on release of a trigger as shown in Fig. 12. The force arises from the rapid deco"~pression of a co"",r~ssed spring. This firing ,-,echan;_... may be made out of any suitable materials and in any shape as would be envisioned by a man skilled 10 in the art. The pre~c ,cd trigger ",echani_." is formed from plastic and is moulded to the users hand.

As shown in Fig. 12 the firing ",echan;sm co",prises an outer case 1301 with a snap in receptor bracket 1302. An opposite case (not shown) enclosesthe n,ccl.an A~ of the firing ",ecl.anic... and may be welded sc,~ ed or vtl,er~i~
athcl,ed to case 1301 at sKes 1314. The ~--ecl-anAc of this firing ~"acl-an;3ln coruprise a firing pin 1304 having lhe,elh,ough formed a slot to accGn.",Gdate acocking device 1305. A stop 1330 on the pin 1304 determines length of stroke by abutment against adjustable stop 1313. A ratchet 1306 on pin 1304 mates with a trigger release 1311 and holds the firing pin against the forced end of the 20 cc "",-essed spring. The pin at the forward end forms a recess 1308 to receive the adapter stud 1211 of the snap adapter assa",bly as shown in Fig. 11. The ,.,echan-~ of the firing n-ccha"i_ri, further co..,pri3es a cam activated cocking device 1305 which pivots on a pin 1309. Cocking device 1305 acts by engager"~rltof the firing pin in cAt~n~hn of the cocking device through the firing pin slot to cause the firing pTn to be pulled back and cG",prass firing pin spring 1310 in ~n,par~ti3n for firing~ The firing pin spring 1310 is carried on the firing pin 1304 and acts between a wall formed on the case 1301 and a flange formed on the firing pin 1304.
Atrigger 1307 cGI"pr;_os a ratchet portion 1311 which mates with the ratchet 1306 on the firing pin 1304. A spring 1312 at the base of the trigger 1307 maintains the mating of the ratchets until released by the dapr.~ g of the trigger 1307 which 2~9~2~i~

extends beyond the case 1301.

The snap adapter asse"lbly 1200 snaps into the firing ".achar,;_l.. and is maintained in position by flange 1315 which mate with grooves 1202 on the snap ~ - -adapter. The adapter stud 1211 fits snugly into the recess 1308 of the firing pin 1304.
., ~
In use the snap adapSer is fit into the recess of the firing pin. The firing mechal,;vfi, is cocked by rotating the cocking device to pull the firing pin back so that the ratchet portion of the pin is engaged with the ratchet portion of the trigger.
In this position the firing pin spring is co"",ressed b~- 2en the flange of the firing 10 pin and the wall of the case. Deco.n~.rtssion of the spring is prevented by the biasing ratchets tog_lhar through the trigger spring. It is to be u,lderatood that since the firing pin is directly connected to the adapbr rod of the snap adapter (which secures the firing wire), any IllO~_.lle-d of the pin is directly transmitted to the wire, which is directly transmitted to the shear. The shear is then d;s~'~c~d rapidly by 15 dap.essi.,g the trigger against the trigger spring which releases the ratchetengage...ant and thereby allows rapid decor..~,r~Kion of the spring resulting rapid '3~--ent of the firing pin. The trigger mechani_.-- p...~;des a co..-~,t~
gripping surface with which to manipulate the longitudinal position of the sheanDepending on the application, the characteristics of the spring .nechan;_." or other 20 means used to provide the energy for the cutting thrust can be adjusted, so as to provide fasbr or slower or more or less force in the cutting thrust~

The trigger mechal.i3m is detachable from the housing assembliês so that housing assemblies may be used, di ~posed of and re~,l.Jced wKh sbrile catheter 25 as~emblles while the trigger assembiy may be reused~

The flring wire used in the various embodiments of the invention may be made of any high bnsile steel or other mabrial which can transmK a powerful : ., 2~9~2~

thrust and force repe~tedly. The firing wire may also be used in a variety of dirf~rent ~lia",el~r~ depending on the type of cdll,~ t~r the size of catl.~te" and the amount of force being transmitted. P,ererably the dia",eter ranges from about .010"
to .014". The firing wire can also be of any cross section and may also be of varying lengths depending on the procedure in which it is going to be used (i.e.heart or fallopian tube or other procedure). The firing wire is dlldched to the shear ~-at either the forward end or, more pr~f~ led the rearward end. The atldChll ,ent may be bonded crimped snapped or welded. If large enough the dtlacl""er,t of the firing wire to the shear could be done on a II.reacled basis or with two grub screws 10 1209 pinching the firing wire to the firing ,echafii-." through an atldchr"ent called the snap adapter asse,~ ly. In the pr~.f~ d embodiment the firing wire is weldedto the inside of the shear. At the trigger ".ecl,an;s.,. it is p~f~ ..ed that two grub screws would pinch the firing wire to the snap adapter asser"bly as shown in Fig.
11. , , The firing wire projects the dtla~hed shear positively within the ~dtl,t:ter housing with sul ~lanlial force transferred from the trigger asser,lLly. The result is a quick smooth and clean cut of the lalge~ obstruction. In the pref~ r,ed embodiment, incor~,orati"g an extruded tube the firing wire does not bend or kink as it transmits force to the shear as it is contained within another lumen as shown in Fig. 9. An alternative is that the firing wire 104 is att~ched to the shear 230 to pull it back along the housing to excise the debris.

OPERATION OF PKt~tKKtL~ EMBODIMENTS

Figure 13 indicates an example of an arterial view showing the process of the removal of the debris within an artery prog.ess.vely in views 14A through to 14C.

The catheter of the present invention is located in an artery according .~

-- ~09~2~

to known techniques, such as use of a fluoroscope and dye injected into the artery.
In this desc,i~lion, the housing may be s~lec~ d from the embodiments of Fig. 2 through Fig. 7 or a cor,lb ,dlion thereof. The location of the ld,yeted obstruction is first iclenli~ied using known IllelllOds. To prevent dalllage to the artery while the 5 housing is being inserted into the artery, it is prerel ~!e that the primary shear be at the forward end of the housing closing or blocking the opening. In this way the cutting edge of the primary shear is effectively shedUIed behind the lip of the housing. This is adjusted through adjustment of the length of the firing wire using the adapter stud.
..:
Since the housing may be moveable or fixed along the guide wire the housing may be positioned in two ways. If the housing is moveable along the guide wire a two step process is used. First, the guide wire is inserted slowly into the a~pn,pridte artery, then the housing at the end of the wire is then pushed manually along the guide wire about the same distance. This process is repeated until the15 obstruction is ,eached. Altematively, in the fixed housing lechn ,~e the guide wire and the housing are fed togétl,er into the artery until the obstruction is ~eached.

As shown in view 14A of Fig. 13, once the location of the obstruction is ,eached, the housing is oriented so that the obstruction is aJ~acent the opening in the housing, the primary shear is moved back so that the obstruction may at least 20 partly (and p,ef~,,ably mostly) protrude into the opening. The extent of the obstruction protrusion into the opening will depend in part on the configuration of the opening, for example, the opening may extend around the circulll' ence of the housing. The anchors are inflated to securely position the housing in relation to the obstruction. The trigger may then be operated manually to move the primary 25 shear in the housing to excise the obstruction as shown in view 14B. The shearing action may be ,ap~ntrd if necesC~y to cor, pl t~ the excision of the obstruction.
Therapeutic agents such as a coaglllnrlt and/or a cau~. ri~i.lg agent may be injected to the tr~eatment site through the extruded tubing.

?

2~82~

In the case of the embodiment shown in Figs. 3A and 3B, the firing wire 104 may be used to pull the primary shear 330 rearward to cor"press the spring 350, and then the firing wire 104 may be released so that the spring 350 urges the primary shear 330 forward in the housing 310 to excise the obstruction.
The firing wire 104 may also be operaled simultaneously with the spring 350 to assist the spring 350 (and vice versa).

The part of the obstruction that is excised by the primary shear falls into the cylindrical body of the primary shear as shown in view 14C and is snayged by the roughened inner surface of the shear. Any debris may also be caught by the screens 252 (if p,esent) or packed into the reservoir by means of the packing stub of various embodiments. If necess~ry the cutting action of the primary shear maybe repeated to remove more of the obstruction. Suction rnay be applied to pull debris into the reservoir or to remove debris. Alternatively, fvios may be injected to clear debris from the housing.

The primary shear is then held in place blocking the opening while the ~th_t~,r housing is withdrawn, reposNioned or rotated along 360 deg~es. If the obstruction has been stored in the catheter, the obstruction may be removed fromthe housing and discdrded or analyzed as desired. Since the cdtl,eler is des4"edto be simple and i"oA~,ensP~e, the catheter may also be di_cd,ded.
... .
In- some cases, where the obstruction does not protrude into the opening in the housing simply by p6ce",ent of the housing a~jace"l the obstruction or the housing is not remaining slationaly in the artery, the saline anchor may then be uA~.anded to secure the housing against the wall of the artery over the obstructbn so that the obstruction protrudes into the opening of the housing.

'~S A person skilled in the art could make immaterial modifications to the inventio~n descril,ed and claimed in this patent without departi.,g from the essence of the invention. The features of the various embodiments as illustrated in the 4 ~ ~ :

Figures of the invention are i"lended not to be limiting but to be i"~rchanged depending on the inlended use of the catheter.
: ~ .
The cdtl,~ ter could be operated in reverse so that the cutting edge was at the rearward end of the primary shear. Thus the opening could also be orie,lted 5 more to the rear of the housing. Thus it should be ~ "de,~ od that the forward and rearward terminology in the claims may be reversed. Il~eirer this is not a preferred manner of ope,ating the catheter. It is pref~r,dd that the shear be operated in the direction of the blood flow. ~ . r"..t;"_ly the primary shear could be given a degree of rGt~thnal movement across the opening but this complicates the10 operdtion of the cdtl,~t~ r and is not pr,_f~ .,dd.

Also the housing and the primary shear need not be cylindrical although it is considered desirable that the housing have a cross-secl;onal shape that is similar to that of an artery.

It is illlpGIt~al)t thatthe primary and secondary shears are sharp enough 15 that they engage and clearly cut the obstruction to prevent the obstruction being simply pushed out of the way during the involvement of the shear. Also the cables used to operate the primary shear should be stffl enough to exert sufficient force on the primary shear to pierce the obstruction.
.. ..

..,-.. ~.,

Claims (34)

1. A catheter for excising obstructions from within a body channel comprising:

(a) a hollow, substantially cylindrical housing, the housing having a lateral opening for accepting an obstruction;

(b) a hollow, cylindrical shear having a base portion and a cutting edge disposed within the housing and moveable across the opening;

(c) a firing tube attached about the base portion of the shear, which firing tube may transmit force to the shear and which may provide fluid communication with the interior of the shear; and (d) means for locating the housing in the channel.
2. A catheter for excising obstructions from within a body channel comprising:

(a) a hollow, substantially cylindrical housing, the housing having a lateral opening for accepting an obstruction;

(b) a hollow, cylindrical shear having a base portion and a cutting edge disposed within the housing and moveable across the opening;

(c) a firing wire connected to the base portion of the shear by means of a base clamp which distributes the force transmitted by the wire about the circumference of the shear; and (d) means for locating the housing in the channel.
3. The catheter of claim 1 or 2 wherein the housing has a nose end and a rearward end having an opening continuous with a communicating tube for allowing communication with the interior of the housing from outside the channel.
4. The catheter of claim 1 or 2 wherein the housing is adapted to allow the freemovement of body channel fluid through the housing.
5. The catheter of claim 3 wherein the communicating tube further acts as a conduit for a combination of fluid tubes and stabilizing wires.
6. The catheter of claim 1 or 2 wherein the shear has a roughened inner surface for engaging an excised obstruction.
7. The catheter of claim 1 or 2 further comprising an anchoring system for anchoring the housing within the body channel.
8. The catheter of claim 7 wherein the anchoring system comprises a plurality ofexpandable bladders disposed on the housing substantially opposite the lateral opening.
9. The catheter of claim 3 wherein the shear has a roughened inner surface for engaging an excised obstruction.
10. The catheter of claim 3 further comprising a packing stub disposed within the housing to pack the excised parts of the obstruction further into the housing.
11. The catheter of claim 3 further comprising an anchoring system for anchoring the housing within the body channel.
12. The catheter of claim 7 wherein the anchoring system comprises a plurality of expandable bladders disposed on the housing substantially opposite the lateral opening.
13. A catheter system for excising obstructions from within a body channel comprising:

(a) a hollow, substantially cylindrical housing adapted for entry into the channel, the housing having an opening for accepting an obstruction;

(b) a hollow, substantially cylindrical primary shear disposed within the housing and moveable across the opening;

(c) force transfer means connected to the primary shear and operable from outside the body channel for urging the shear to move within the housing and across the opening to create a guillotine action;

(d) triggering means for triggering the force transfer means to urge the shear movement from a location external of the body channel, and (e) means for locating the housing in the channel.
14. The catheter system of claim 13 wherein the triggering means is a hydraulic mechanism.
15. The catheter system of claim 13 wherein the triggering means is an electro-mechanical mechanism.
16. The catheter system of claim 13 wherein the triggering means is a mechanical mechanical
17. The catheter system of claim 16 wherein the mechanical mechanism comprises a firing pin wherein any movement by the firing pin is directly translated to the shear by the force transfer means.
18. The catheter system of claim 17 wherein the mechanical mechanism further comprises a firing pin spring biased on the firing pin and a trigger such that the firing pin is driven to move by decompression of the firing spring when the firing spring is triggered to decompress by means of the trigger.
19. The catheter system of claim 18 wherein the firing pin is driven to move in a longitudinal direction and the longitudinal movement is directly transmitted to the shear such that it also moves in a longitudinal direction within the housing.
20. The catheter system of claim 18 wherein the mechanical arrangement further comprises a cocking means to recompress the firing pin spring.
21. The catheter system of claim 13 wherein the force transfer means and the means for locating the housing in the channel are accommodated together in a protective sleeve extending between the triggering means and the housing.
22. The catheter system of claim 13 wherein an adapter is disposed between the force transfer means and the triggering means to allow fine adjustments of the force transfer means and to allow free rotation of the triggering means about the force transfer means.
23. The catheter system of claim 13 wherein the force transfer means is a firing wire.
24. The catheter system of claim 21 wherein the protective tube further acts as a conduit for a combination of fluid tubes and stabilizing wires.
25. The catheter system of claim 21 wherein a rearward end of the housing opens directly into the protective sleeve.
26. The catheter system of claim 13 wherein the shear is hollow and substantially cylindrical and fits concentrically within the housing in close proximity to the housing.
27. The catheter system of claim 26 wherein the shear has a hollow ground cutting edge disposed directly adjacent the housing and the opening is sharpened about its boundaries to enhance the guillotine action.
28. The catheter system of claim 26 wherein the shear has a roughened inner surface of engaging the excised obstruction.
29. The catheter system of claim 26 wherein the force transfer means is a firing tube attached about a base portion of the cylindrical shear.
30. The catheter system of claim 26 wherein the force transfer means is a firing wire is attached to the shear by means of a base clamp which acts to distribute the force transmitted by the wire about the radius of the shear and thereby to stabilize the movement of the shear within the housing.
31. The catheter system of claim 30 wherein the base clamp has apertures to allow the free movement of the fluids of the body channel through the base clamp.
32. The catheter system of claim 13 wherein a packing stub is disposed within the housing to push and pack the excised parts of the obstruction further into the housing.
33. The catheter of claim 13 further comprising an anchoring system for anchoring the housing within the body channel.
34. The catheter system of claim 33 wherein the anchoring system comprises a plurality of fluid fillable bladders disposed about the housing opposite the opening which, when filled, urge the opening of the housing toward a wall of the body channel.
CA 2098246 1993-06-11 1993-06-11 Catheter and method of use thereof Expired - Fee Related CA2098246C (en)

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CA 2098246 CA2098246C (en) 1993-06-11 1993-06-11 Catheter and method of use thereof

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Application Number Priority Date Filing Date Title
CA 2098246 CA2098246C (en) 1993-06-11 1993-06-11 Catheter and method of use thereof
PCT/CA1994/000338 WO1994028803A1 (en) 1993-06-11 1994-06-10 Catheter and method of use thereof
AU70656/94A AU7065694A (en) 1993-06-11 1994-06-10 Catheter and method of use thereof

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CA2098246A1 CA2098246A1 (en) 1994-12-12
CA2098246C true CA2098246C (en) 1999-05-04

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WO (1) WO1994028803A1 (en)

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US5879365A (en) * 1995-04-04 1999-03-09 United States Surgical Corporation Surgical cutting apparatus
US8048101B2 (en) 2004-02-25 2011-11-01 Femasys Inc. Methods and devices for conduit occlusion
US9238127B2 (en) 2004-02-25 2016-01-19 Femasys Inc. Methods and devices for delivering to conduit
US8052669B2 (en) 2004-02-25 2011-11-08 Femasys Inc. Methods and devices for delivery of compositions to conduits
US8048086B2 (en) 2004-02-25 2011-11-01 Femasys Inc. Methods and devices for conduit occlusion
US9554826B2 (en) 2008-10-03 2017-01-31 Femasys, Inc. Contrast agent injection system for sonographic imaging
US10070888B2 (en) 2008-10-03 2018-09-11 Femasys, Inc. Methods and devices for sonographic imaging
GB2554375A (en) * 2016-09-22 2018-04-04 Snakebite Medical Ltd Device

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DE1766252A1 (en) * 1968-04-25 1971-06-16 Medizin Labortechnik Veb K Curette
US3561429A (en) * 1968-05-23 1971-02-09 Eversharp Inc Instrument for obtaining a biopsy specimen
US3590808A (en) * 1968-09-04 1971-07-06 Us Catheter & Instr Corp Biopsy tool
DE2453058A1 (en) * 1974-11-08 1976-05-20 German Prof Dr Schmitt Excision head for tissue sample removal in vivo - has sliding knife which cuts tissue protruding through aperture in casing wall
US4846192A (en) * 1987-04-17 1989-07-11 Eastman Kodak Company Rearwardly acting surgical catheter
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WO1992014413A1 (en) * 1991-02-19 1992-09-03 Fischell Robert Improved apparatus and method for atherectomy

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AU7065694A (en) 1995-01-03
CA2098246A1 (en) 1994-12-12

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