Embolus supply system and method

An apparatus and method is provided for dispensing coil emboli one at a time in a controlled and reliable manner during surgery to embolize several blood vessels or the like in a body. The apparatus includes a magazine that is movable within a dispenser housing to position each of the embolus cartridges contained in the magazine one at a time at a dispensing station on command. A stream of pressurized fluid is injected or a guide wire is inserted into the embolus cartridge held in the dispensing station to dislodge an embolus contained therein and discharge it into an embolus-delivery catheter coupled to the dispenser housing. Afterwards, the magazine is moved within the dispenser housing to remove the just-emptied embolus cartridge from the dispensing station and load a fresh embolus cartridge into the dispensing station.

BACKGROUND AND SUMMARY OF THE INVENTION 
This invention relates to a vessel occlusion system, and particularly to a 
system for supplying an embolus to a catheter or the like for delivery 
into a vessel situated in a body to occlude or close the vessel. More 
particularly, this invention relates to an apparatus and method for 
selecting an embolus and moving it through an introducer catheter inserted 
through a venotomy into a body to reach a destination in a blood vessel or 
the like and occlude the vessel during a surgical or percutaneous 
interventional vascular procedure. 
Embolization is a procedure used by surgeons and vascular 
interventionalists (probably radiologists and cardiologists) to block 
fluid flow through a blood vessel or organ. Typically, a mass of material 
called an embolus is inserted into a body using a catheter and lodged in a 
blood vessel or organ to Provide an obstruction therein. Lodging an 
embolus in a blood vessel obstructs blood flow through the vessel and 
causes a thrombus or blood clot to develop in the vessel. The thrombus 
remains attached to the embolus and blood vessel wall at its place of 
origin to plug the vessel and obstruct blood or other fluid flow 
therethrough. 
Embolization is used, for example, for therapeutic purposes to reduce blood 
loss during hemorrhage or treatment of unresectable lesions or to permit 
preoperative control of blood flow. Embolization of feeding vessels is 
known to reduce bleeding during surgery. For example, it is used in 
surgery prior to resection of vascular tumors. 
Many types of emboli are known. For example, coils made of spring wire, 
sponges made of absorbable gelatin or other chemical cross-linking means 
such as cyanoacrylate or the like, detachable balloons, umbrella-like 
devices, and other types of plugs are used to embolize a vessel. Any 
device which has thrombotic properties when placed in a vessel having a 
proper internal diameter and does not cause significant foreign body 
reaction can be used to embolize a vessel to occlude the vessel totally or 
partially. 
A guide wire can be used to load an embolus into an introducer catheter or 
to discharge an embolus from its place in an introducer catheter into a 
vessel or both. A guide wire sized to pass through the lumen of the 
introducer catheter can be used to move an embolus into and out of an 
introducer catheter as long as the surgeon has the necessary skill and 
expertise. 
According to the present invention, an apparatus is provided for supplying 
an embolus to a delivery tube such as a catheter. The apparatus includes a 
magazine containing a plurality of emboli to be discharged one at a time 
into the delivery tube. The magazine is movable relative to the delivery 
tube to place one of the emboli stored in the magazine in a position 
opposite the mouth of the delivery tube. A discharge means is used to 
discharge the selected embolus from the magazine into the delivery tube. 
Advantageously, the present invention provides an apparatus and method for 
selectively discharging a single embolus from a magazine containing many 
emboli and hydraulically delivering the discharged embolus into a catheter 
already inserted into a patient's vein or artery. In one embodiment, 
hydraulic means is used to discharge the embolus from the magazine to a 
destination and, in another embodiment, a mechanical means such as a guide 
wire is used instead of the hydraulic means to discharge the embolus. 
During vascular surgery, the embolus is moved either hydraulically or 
mechanically through the catheter and is deposited in a blood vessel 
connected to the vein or artery upon exiting the catheter. 
The apparatus is particularly well-suited for use during endoluminal vein 
preparation for in-situ bypass. This is a surgical procedure designed to 
reconfigure the vein to function as an artery so that the vein can be 
surgically adapted to replace a naturally occluded, malfunctioning artery 
in a leg or other portion of a body. Each embolus discharged from the 
magazine is delivered to a blood vessel branching out from the vein and 
deposited therein to help occlude the blood vessel. The apparatus is also 
well-suited for use in varicose vein surgery and occluding the smaller 
branches of an artery exposed during surgery, such as during aneurysm 
repair. 
In preferred embodiments, the magazine contains a plurality of separate 
embolus cartridges arranged side-by-side in a series. Each embolus 
cartridge holds a single embolus and is formed to include a through 
passageway containing the embolus. The magazine is movable inside a hollow 
housing to align each cartridge in the series one at a time in an 
embolus-discharging position or station located within the housing. The 
hollow housing includes an inlet coupled to a fluid supply system and an 
outlet coupled to the delivery tube. An embolus cartridge aligned in the 
embolus-discharging position is connected to the housing inlet and outlet 
to conduct fluid from the fluid supply system to the delivery tube through 
the passageway in the embolus cartridge containing the embolus. 
A stream of pressurized fluid is generated using fluid from the fluid 
supply system and used to move the magazine inside the housing so that 
each embolus cartridge in the series is aligned one at a time in sequence 
in the embolus-discharging position within the housing. Illustratively, 
the apparatus includes a cylinder for receiving the stream of pressurized 
fluid and a mechanical linkage for advancing the magazine along a guide 
path within the housing. A piston is movable in the cylinder to operate 
the mechanical linkage and advance the magazine along the guide path in 
response to input of pressurized fluid into the cylinder. The mechanical 
linkage is constructed to ensure that the magazine is moved incrementally 
within the housing to place each embolus cartridge in sequence in the 
embolus-discharging position. 
Once an embolus cartridge has been moved to the embolus-discharging 
position in the housing, the stream of pressurized fluid in the cylinder 
is passed through an aperture formed in the piston and into the 
embolus-containing passageway in the embolus cartridge. The embolus is 
discharged by the stream of pressurized fluid from the embolus cartridge 
and magazine into the delivery tube through the housing outlet to empty 
the embolus cartridge positioned in the embolus-discharging station. The 
fluid used to flush the embolus through the delivery tube is water or 
another biologically compatible fluid such as saline. The fluid-powered 
mechanical linkage then operates automatically to move the magazine inside 
the housing to "reload" the embolus supply apparatus so that a 
just-emptied embolus cartridge is moved out of the embolus-discharging 
position and a next "loaded" embolus cartridge is moved into the 
embolus-discharging position and connected to the fluid supply system at 
the housing inlet and the delivery tube at the housing outlet. 
A supply of fluid is provided and a predetermined volume of fluid from the 
supply is pressurized at a predetermined rate to generate the stream of 
pressurized fluid. For example, it has been observed that only 0.5-3 cubic 
centimeters of fluid are needed to deliver an embolus to a target site in 
a collateral blood vessel. 
The embolus is preferably a normally coiled spring that has been 
straightened to a somewhat linear shape to assume an "uncoiled" 
configuration for containment in the cylindrical passageway formed in the 
cartridge. The tendency for the uncoiled spring to reconfigure itself to 
its coiled configuration causes the spring (embolus) to exert a 
predetermined force against an interior wall defining the passageway to 
retain the spring (embolus) temporarily in an initial position within the 
cartridge passageway. Advantageously, the stream of pressurized fluid is 
used to apply a predetermined amount of work to the embolus to overcome 
frictional forces between the embolus and the interior wall of the 
cartridge passageway to dislodge the embolus from its place in the hollow 
cartridge so that it can be moved by the stream of pressurized fluid 
through the catheter to reach its destination in the vessel. 
Illustratively, the catheter used to deliver the embolus to the target site 
is guided through various body passageways to reach the target site by 
means of a second catheter having a lumen sized to receive the 
embolus-delivery catheter therein. The second catheter is preferably 
steerable and aimable by remote control to guide the embolus-delivery 
catheter extending therethrough to the mouth of the selected blood vessel 
or organ containing the target site. 
Advantageously, the apparatus of the present invention permits a surgeon to 
embolize one or more vessels or organs in a body without using a guide 
wire to push an embolus into or through an embolus-delivery catheter to 
reach the target site in the body. A catheter used to deliver emboli is 
sometimes called an "introducer" catheter. Further, use of a stream of 
pressurized fluid to move am embolus from a hollow cartridge through an 
introducer catheter provides an embolus delivery system that is easily 
manageable by the surgeon during embolization. Such a hydraulic system 
offers many advantages in use because it operates to cause a uniform, 
predetermined force to be applied to an embolus on command during each 
embolization. This technique enhances a surgeon's ability to position an 
embolus properly at a target site in a vessel once the embolus has emerged 
from the distal end of a catheter. 
Illustratively, the method and apparatus of the present invention can be 
used by a surgeon to perform a vein bypass of femoro-popliteal, 
femoro-tibial, or femoro-pedal arteries. After embolizing each side branch 
of a vein extending through the leg of a patient, the vein can be 
surgically reconfigured to function as an artery and "replumbed" to 
replace a malfunctioning artery that is unable to conduct an adequate flow 
of blood therethrough. Using the catheter-based embolus delivery system, 
vein side branch embolization is achievable without making a long incision 
along the length of the leg in accordance with present accepted medical 
practice. 
Additional features and advantages of the invention will become apparent to 
those skilled in the art upon consideration of the following detailed 
description of preferred embodiments exemplifying the best mode of 
carrying out the invention as presently perceived.

DETAILED DESCRIPTION OF THE DRAWINGS 
During vascular surgery, surgeons often find it necessary to occlude or 
ligate certain veins, arteries, or collateral blood vessels to control 
blood flow through the body undergoing an operation. Typically, the blood 
vessels collateral to the saphenous vein in the leg must be ligated during 
vascular surgery to reconfigure the vein to function as an artery. Of 
course, it is also desirable to occlude body organs other than blood 
vessels in the course of other surgical procedures. 
The improved apparatus of the present invention advantageously is 
well-suited for delivering coil emboli to a vessel in a simple, efficient, 
repeatable, and predictable manner. Means is provided for inserting an 
embolus into an introducer catheter quickly and easily and also 
discharging the embolus from the introducer catheter into a selected 
vessel in a body using either pressurized fluid or a guide wire. 
A system 10 for transcatheter embolization of selected vessels or organs in 
a body is illustrated in FIG. 1. Advantageously, this system 10 is 
well-suited for delivering a coil embolus 12 (or other embolus) to a 
target site in a body vessel or organ. Once it reaches the target site, 
the coil embolus 12 partly occludes the vessel and causes a blood clot to 
"organize" around the coil embolus 12 at the target site. Later, the blood 
clot becomes solid with ingrowth of cells and fibrous tissue to occlude 
the vessel totally. It will be appreciated that the system 10 could be 
used to deliver various emboli other than coil emboli 12. 
Embolus-delivery system 10 includes a feeder assembly 14, an introducer 
catheter 16 coupled to an outlet fixture 18 of the feeder assembly 14, and 
a fluid supply assembly 20 coupled to an inlet fixture 22 of the feeder 
assembly 14. The fluid supply assembly 20 is used to deliver a stream of 
pressurized fluid into the interior region 24 of feeder assembly 14 to 
move an embolus 12 out of its home therein and into and trough introducer 
catheter 16 toward its destination outside of the introducer catheter 16 
in a blood vessel or the like. System 10 renders obsolete any need to use 
a guide wire or other instrument to load an embolus into an introducer 
catheter and discharge an embolus from an introducer catheter. In the 
alternative embodiment of FIG. 14, syringe means 300 is used to generate a 
stream of pressurized fluid and a tube 314 is used to deliver that stream 
of pressurized fluid into the interior region of feeder assembly 14 to 
discharge an embolus therein into introducer catheter 16. 
Fluid supply assembly 20 includes a fluid reservoir 26, a pressure system 
28, a waste fluid reservoir 29, and an actuator means 30. The actuator 
means 30 is operable manually or by remote control to cause either a 
stream of pressurized fluid from fluid reservoir 26 to be injected into 
the feeder assembly 14 or a volume of waste fluid from the feeder assembly 
14 to be routed to the waste fluid reservoir 29. Pressure system 28 
pressurizes fluid in fluid reservoir 26 to generate a source of 
pressurized fluid that can be injected into the feeder assembly 14 at the 
command of the surgeon. The surgeon need only activate the actuator means 
30 of fluid supply assembly 20 to cause a stream of pressurized fluid to 
be injected through inlet fixture 22 into feeder assembly 14. 
Actuator means 30 is operable to control whether fluid flows into or out of 
feeder assembly 14. The actuator means 30 illustratively includes a 
two-position fluid switch 31 having a first stage fluid-channeling means 
32 and a second stage fluid-channeling means 34. Each of these 
fluid-channeling means 32, 34 is shown diagrammatically in FIGS. 1 and 1a. 
Fluid switch 31 is movable between a "normal" waste fluid-discharge 
position shown in FIG. 1 and a pressurized fluid-input position shown in 
FIG. 1a. 
In its "normal" position, the first stage fluid-channeling means 32 of 
fluid switch 31 operates as shown in FIG. 1 to conduct waste fluid 
discharged from the feeder assembly 14 to the waste fluid reservoir 29. 
The waste fluid is conducted from feeder assembly 14 through a transfer 
conduit 36 coupled to an inlet tube 38 of inlet fixture 22, fluid switch 
31, and a waste conduit 40 coupled to waste fluid reservoir 29. Of course, 
waste conduit 40 could instead be coupled to fluid reservoir 26 if it is 
advantageous to recycle the fluid used to operate system 10. 
Essentially, the first stage fluid-channeling means 32 in fluid switch 31 
includes a passageway 41 configured to interconnect transfer conduit 36 
and waste conduit 40 so that waste fluid can flow therebetween. The first 
stage means 32 also includes a closure mechanism 43 configured to close a 
supply conduit 42 coupled to fluid reservoir 26 to block discharge of 
pressurized fluid therefrom. Accordingly, in the normal position of fluid 
switch 31 shown in FIG. 1, the supply conduit 42 that is coupled to the 
fluid reservoir 26 is not ale to supply pressurized fluid to the feeder 
assembly 14. Therefore, no pressurized fluid is introduced into the feeder 
assembly 14. A return spring 44 or the like is provided and arranged to 
yieldably bias the fluid switch 31 to assume the normal position shown in 
FIG. 1. 
The actuator means 30 also includes push-button means 44 or the like for 
moving the two-position fluid switch 31 against the biasing force provided 
by return spring 44 to assume the pressurized fluid input position as 
shown illustratively in FIG. 1a. In this position, the second stage 
fluid-channeling means 34 in fluid switch 31 operates to conduct a stream 
of pressurized fluid discharged from fluid reservoir 26 to the feeder 
assembly 14 via the supply conduit 42 and the transfer conduit 36. This 
stream of pressurized fluid is routed along a predetermined path 
(described in more detail below) through the interior region 24 of the 
feeder assembly 14 so that it intercepts a single embolus 12 contained 
therein and flushes that embolus 12 out of the feeder assembly 14 through 
the outlet fixture 18 and into the introducer catheter 16. The use of a 
stream of pressurized fluid to flush an embolus 12 out of feeder assembly 
14 and into an introducer catheter 16 is shown best in FIG. 6. 
Essentially, the second stage fluid-channeling means 34 in fluid switch 31 
includes a passageway 48 configured to interconnect transfer conduit 36 
and supply conduit 42 so that pressurized fluid can flow therebetween. The 
second stage means 34 also includes a closure mechanism 50 configured to 
the close waste conduit 40. Once the push-button means 44 is manually or 
automatically released, the return spring 44 operates to move the fluid 
switch 31 from its pressurized fluid-input position shown in FIG. 1a to 
its normal waste fluid-discharge position shown in FIG. 1. 
Feeder assembly 14 is illustrated in more detail in FIGS. 2 and 3. A 
movable magazine 52 is situated in the interior region 24 of feeder 
housing 54 and configured to hold several embolus cartridges 56 side by 
side one another. As shown best in FIG. 4, each embolus cartridge 56 is 
formed to include a passageway 58 extending therethrough and containing a 
coil embolus 12 that has been "straightened" somewhat to fit and remain in 
passageway 58 until a stream of pressurized fluid is injected into 
passageway 58 to dislodge and discharge the embolus 12. Each embolus 
cartridge 56 also includes an enlarged outlet head 60 at its front end and 
an enlarged inlet head 62 at its rear end. When each cartridge 56 is 
loaded into a mounted position in magazine 52 as shown in FIG. 2, the 
inlet head 62 abuts a first cartridge support wall 64 on magazine 52, the 
outlet head 60 abuts a second cartridge support wall 66 on magazine 52, 
and the elongated shaft 68 extending between inlet and outlet heads 62, 60 
extends across the width of magazine 52. 
As shown in FIG. 4, an embolus 12 is deposited in the cartridge passageway 
58 in, for example, a central region 57 so that it is ready to be 
discharged through outlet head 60 whenever it is "hit" by the slug of 
fluid expelled from fluid supply assembly 20. As shown in FIG. 4, embolus 
12 is initially packed into passageway 58 to load the cartridge 56. In the 
case of a coiled spring embolus 12, it is unraveled to assume a somewhat 
straight shape and loaded into the passageway 58 during factory assembly 
of cartridge 56. Essentially, the coiled spring 12 is uncoiled or 
straightened to assume a packed position in the passageway 58 and 
configured to exert a light predetermined force against the interior wall 
of the passageway 58 to retain the spring 12 in the cartridge 56 until a 
stream of pressurized fluid 32 is injected into passageway 58. 
It will be appreciated that a variety of coiled spring emboli are available 
in the marketplace. Presently, a helical coil or curled segment made of 
small diameter platinum wire without any fiber tails or threads attached 
thereto is the preferred embolus to use in connection with 
embolus-delivery system 10. For example, suitable coil emboli are 
available from Target Therapeutics, Inc. of San Jose, Calif. 
As shown in FIG. 4, a coiled spring embolus 12 can be uncoiled and 
straightened using suitable automated or manual means to permit loading 
into the cartridge passageway 58. Such an embolus 12 is retained 
temporarily in a fixed position in passageway 58 by frictional engagement 
of the coiled spring embolus 12 against the interior wall. The internal 
diameter of passageway 58 is matched to the size of embolus 12 to be 
retained therein to ensure that the straightened spring embolus 12 is 
unable to move to assume its original helical or coiled shape. However, 
injection of a stream of pressurized fluid into the inlet head 62 of 
passageway 58 at a sufficient rate will apply enough work to the spring 12 
to overcome frictional forces between the spring 12 and the passageway 
wall, thereby dislodging the spring 12 and discharging it from cartridge 
56 through outlet head 60. Once spring 12 emerges from the introducer 
catheter 16 at the target site in a vessel, it will coil or "reform" to 
assume a coiled shape similar to its original helical shape as shown in 
FIGS. 1 and 6. 
The magazine 52 is configured to hold a series of embolus cartridges 56 in 
side-by-side spaced-apart parallel relation as shown in FIG. 2. The 
magazine 52 is movable inside feeder housing 54 along guide rails 70, 72 
in forward direction 74 to place each embolus cartridge 56 one at a time 
in an embolus-discharging position or station (shown in FIG. 5) between 
inlet fixture 22 and outlet fixture 18. In the embodiment shown in FIGS. 
1-8, means is provided in the inlet fixture 22 for using a stream of 
pressurized fluid supplied by the pressure system 28 and introduced into 
inlet tube 38 to move the magazine 52 in the forward direction 74 on guide 
rails 70, 72 and in the sideways direction 76 away from guide rails 70, 72 
so that each embolus cartridge 56 in the magazine 52 is aligned in 
sequence one at a time in the embolus-discharging position within the 
feeder housing 54. 
As will be explained in more detail below, once the magazine 52 is moved to 
align an embolus cartridge 56 in the embolus-discharging position shown in 
FIG. 5, some of the pressurized fluid received in inlet fixture 22 is 
injected into the through passageway 68 formed in cartridge 56 to dislodge 
the coil embolus 12 provided therein and flush the embolus 12 out of 
cartridge 56 and into and through the introducer catheter 16 coupled to 
outlet fixture 18. This same pressurized fluid has sufficient velocity to 
transport the embolus 12 through the introducer catheter 16 and expel the 
embolus 12 from catheter 16 to reach a target destination in a blood 
vessel (not shown) or the like. 
Inlet fixture 22 includes a cylinder 78 formed to include a cylindrical 
closed chamber 80 sized to receive a reciprocable sealed piston 82 therein 
as shown, for example, in FIGS. 2, 5, 6, and 7. A first spring 84 is 
provided in closed chamber 80 for yieldably biasing piston 82 toward the 
inlet tube 38 against a seat 86 positioned near the inlet end of cylinder 
78. Injection of a stream of pressurized fluid through inlet tube 38 into 
closed chamber 80 of cylinder 78 will cause the piston 82 to move against 
the biasing force of first spring 84 to a projected position shown in FIG. 
5 so that the space 88 in closed chamber 80 between inlet tube 38 and 
piston 82 will fill with pressurized fluid 90 received from fluid 
reservoir 26. 
As shown best in FIGS. 5 and 6, piston 82 and a tubular shaft 92 appended 
thereto are formed to include a passageway extending therethrough for 
conducting pressurized fluid 90 from space 88 in cylinder 78 into the 
through passageway 58 formed in the embolus cartridge 56. An axially outer 
small diameter aperture 94 and an axially inner larger diameter aperture 
96 formed in piston 82 and a longitudinally extending aperture 98 formed 
in tubular shaft 92 cooperate to define the passageway through piston 82 
for conducting pressurized fluid 90 from cylinder 78 to embolus cartridge 
56. 
A valve assembly is provided in piston assembly 82, 92 for controlling 
passage of pressurized fluid through the piston passageway 94, 96, 98. 
Valve assembly includes a ball valve 110 in the large diameter aperture 96 
in the piston 82 and a spring 112 in the longitudinally extending aperture 
98 in tubular shaft 92. As shown in FIG. 5, spring 112 acts against a 
ledge inside the tubular shaft 92 to yieldably bias ball valve 110 into 
engagement with a valve seat in the large diameter aperture 96 to block 
the flow of pressurized fluid 90 from the small diameter aperture 94 into 
the large diameter aperture 96 and longitudinally extending aperture 98. 
It will be appreciated that the spring 112 is strong enough so that it will 
not yield and allow pressurized fluid 90 to move from the space 88 in 
cylinder 78 past the ball valve 110 and into the through passageway 58 in 
embolus cartridge 56 until after the outlet head 60 of embolus cartridge 
50 is moved to establish a leak-free sealed connection with the outlet 
fixture 18. Otherwise, pressurized fluid 90 injected from cylinder 78 into 
the through passageway 58 in embolus cartridge 56 might inadvertently leak 
into the interior region 24 of the feeder housing 54 instead of passing 
directly into the outlet fixture 18 on its way into the lumen of the 
introducer catheter 16. As shown best in FIG. 6, the distal end of tubular 
shaft 92 is sized and shaped to mate in sealing engagement with the open 
end of the inlet head 62 on the embolus cartridge 56 so that pressurized 
fluid 90 admitted into longitudinally extending aperture 98 is able to 
flow directly into the through passageway 58 formed in embolus cartridge 
56 without leaking. 
Outlet fixture 18 includes a catheter mounting socket 114 and an embolus 
discharge tube 116. The catheter mounting socket 114 extends through a 
side wall of the feeder housing 54 and includes an outwardly facing nipple 
118 sized to connect to an introducer catheter 16 as shown in FIG. 2. 
Embolus discharge tube 116 is appended to an inwardly facing part of 
catheter mounting socket 114. Discharge tube 116 and mounting socket 114 
cooperate to provide a passageway 120 shown best in FIG. 6 for conducting 
an embolus 12 and the pressurized fluid 90 expelled therewith from the 
through passageway 58 of the embolus cartridge 56 into the downstream 
introducer catheter 16. It will be appreciated that the first cartridge 
support wall 64 has an inner side 119 that sealingly mates with the 
downstream end of each cartridge head 60, an outer side 121 having an 
outlet nipple 122 for each cartridge 56 that is able to sealingly mate 
with the upstream end of embolus discharge tube 116, and a short conduit 
124 for conducting the embolus 12 (and pressurized fluid 90 expelled 
therewith) discharged from cartridge 56 in a downstream direction into 
embolus discharge tube 116. 
A magazine return mechanism 126 is mounted on an inside wall of feeder 
housing 54 adjacent to outlet fixture 18 as shown in FIGS. 2, 5, 6, and 8. 
Magazine return mechanism 126 includes a guide clip 128 having a leading 
edge 130 positioned to lie in spaced-apart parallel relation to one of the 
guide rails 70 inside feeder housing 54 as shown best in FIGS. 3, 5, and 
6. A pair of springs 132 act between an upstanding wall 134 on guide clip 
128 and catheter mounting socket 114 to yieldably bias guide clip 128 to 
its projected position shown in FIG. 2. 
A guide bar 136 is appended to the bottom wall of magazine 52 as shown in 
solid lines in FIG. 3 and in phantom lines in FIGS. 2, 5, 6, and 8. Guide 
bar 136 is sized to fit and slide in the space between the leading edge 
130 of guide clip 128 and the side edge 138 of guide rail 70. Although 
springs 132 do yieldably urge the leading edge 130 of guide clip 128 into 
engagement with guide bar 136 on magazine 52, such engagement will not 
substantially obstruct or otherwise hinder sliding movement of magazine 52 
along guide rails 70, 72 in the forward direction 74 as it moves to remove 
an "empty" embolus cartridge 56 from the embolus-discharging position and 
replace it with an adjacent "loaded" embolus cartridge. Springs 132 will 
be compressed during movement of magazine 52 in the sideways direction 76 
as the guide bar 136 is pushed against the leading edge 130 of guide clip 
128 during movement of magazine 52 under a load from its normal position 
shown in FIGS. 2 and 8 to its embolus-discharging position shown in FIGS. 
5 and 6. The springs 132 and guide clip 128 cooperate to return magazine 
52 to its normal position engaging guide rails 70, 72 once the 
movement-inducing load is removed from magazine 52. In the illustrated 
embodiment, tubular shaft 92 is periodically moved in sideways direction 
76 to apply such a movement-inducing load to magazine 52. 
A drive bar 140 is appended to the piston 82 to move therewith and is 
reciprocable in sideways direction 76 and 77 to cause magazine 52 to move 
in forward direction 74. As shown in FIGS. 2 and 3, drive bar 140 extends 
through a slot formed in magazine 52 to pass underneath the guide rail 70 
closest to inlet fixture 22. Drive bar 140 includes a pawl 142 at its 
distal end. Pawl 142 is oriented to project into a serpentine slot 144 
formed in magazine 52 and move therein to control movement of magazine 52 
in forward direction 74. 
As shown best in FIGS. 2, 5, and 8, the serpentine slot 144 includes an 
inlet 146 at one end and an outlet 148 at the other end. A series of 
Y-shaped passages are joined together as if "holding hands" to form the 
serpentine shape of slot 144. Each Y-shaped passage includes an entry arm 
150, a base leg 152, an exit arm 154, and a one-way gate 156 mounted in 
the passage between entry arm 150 and base leg 152 for pivotable movement 
therein. The proximal edge of one-way gate 156 is pivotably appended to a 
portion of magazine 52 situated between entry arm 150 and exit arm 154 so 
that one-way gate 156 can swing in direction 158 from its normally closed 
position shown in FIGS. 2, 5, 7, and 8, to an opened position shown in 
FIG. 7a.. 
One-way gate 156 opens to let pawl 142 pass from entry arm 150 into base 
leg 152 during movement of piston 82 and drive bar 140 in sideways 
direction 76 as cylinder 78 fills with pressurized fluid. However, one-way 
gate 156 closes as shown in FIG. 7 to cause pawl 142 to move from base leg 
152 into exit arm 154 in response to movement of piston 82 and drive bar 
140 in sideways direction 77 as cylinder 78 is emptied of waste fluid. 
Such closure of one-way gate 156 blocks pawl 142 from being returned to 
entry arm 150 in response to movement of piston 82 and drive bar 140 in 
sideways direction 77. 
OPERATION 
A cycle of operation of embolus-delivery system 10 is illustrated in 
sequence in FIGS. 2, 5, and 6. The location of magazine 52 inside feeder 
housing 54 at the beginning of a cycle is shown in FIG. 2. Cylinder 78 
does not yet contain any pressurized fluid and a single embolus 12 is 
lodged temporarily in embolus cartridge 56. Fluid switch 31 is maintained 
by return spring 42 in its waste fluid-discharge position as shown in FIG. 
1 to block admission of any pressurized fluid 90 from fluid supply 
assembly 20 into embolus cartridge 56. 
An embolus 12 can be discharged hydraulically from embolus cartridge 56 
into delivery catheter 16 in the following manner. Push-button means 46 is 
pressed, for example, to move fluid switch 31 to its pressurized 
fluid-input position shown in FIG. 1a. A stream of pressurized fluid is 
now free to flow from fluid reservoir 26 into the space 88 in cylinder 78 
above the piston 82 This surge of pressurized fluid will move piston 82 
against spring 84 in sideways direction 76 and move the drive bar 140 
appended to piston 82 in the same direction. During such movement the pawl 
142 at the end of drive bar 140 will engage the camming surface 160 which 
forms a side wall of entry leg 150. As pawl 142 moves in a straight line 
in direction 76, it will impart a force to cause magazine 52 to slide on 
guide rails 70, 72 in forward direction 74. Magazine 52 is moved by pawl 
142 an increment of one-half step in forward direction 74 so that the 
outlet head 60 of the embolus cartridge 56 that is being moved into the 
embolus-discharging position is moved to lie in opposing relation to the 
inlet opening of the embolus discharge tube 116 coupled to outlet fixture 
18. 
While magazine 52 is moving in forward direction 74 along guide rails 70, 
72 due to camming action of pawl 142 against camming surface 160, the 
tubular shaft 92 moves in sideways direction 76 with the piston 82 to 
engage the inlet head 62 of the embolus cartridge 56 to be loaded into the 
embolus-discharging position. Tubular shaft 92 pushes the magazine 52 
toward outlet fixture 18 to cause the outlet head 60 of said cartridge 56 
to be coupled to the inlet end of embolus discharge tube 116 so that an 
embolus 12 contained in the cartridge 56 can be discharged into delivery 
catheter 16 through embolus discharge tube 116. As shown best in FIG. 5, 
the guide bars 136, 137 of magazine 52 disengage guide rails 70 and guide 
bar 136 is pushed against the leading edge 130 of guide clip 128 to 
compress clip-biasing springs 132. 
As long as cylinder 78 is filled with pressurized fluid 90 and piston 82 
remains in its projected position shown in FIGS. 5 and 6, the outlet 
nipple 122 of the first cartridge support wall 64 of magazine 52 will 
remain in sealing engagement with the embolus discharge tube 116 to 
establish a discharge passageway 58, 124, 120 into the lumen of delivery 
catheter 16. Embolus 12 will remain in embolus cartridge 56 until the 
magnitude of the fluid pressure in cylinder 78 rises to a level sufficient 
to move ball valve 110 against spring 112 to its opened position shown in 
FIG. 6 Once that valve 110 is opened, a stream of pressurized fluid 90 
will flow from space 88 in cylinder 78 through the longitudinally 
extending aperture 98 formed in tubular shaft 92 into the through 
passageway 58 in embolus cartridge 56. This fluid stream will act to 
dislodge the single embolus 12 contained in passageway 58 and carry it out 
of cartridge 56 and into delivery catheter 16 on route to a target site in 
a blood vessel or the like at the distal end of catheter 16. 
Once the embolus 12 has been discharged hydraulically from the first 
embolus cartridge 56 and push-button means 46 is released, return spring 
42 on actuator means 30 will return fluid switch 31 to its normal waste 
fluid-discharge position shown in FIG. 2. As shown in FIG. 1, the fluid 
chamber 88 in cylinder 78 is now coupled to waste fluid reservoir 29 via 
transfer conduit 36, passageway 41, and waste conduit 40. The guide clip 
128 and springs 132 of magazine return mechanism 126 cooperate to push 
magazine 52 back in sideways direction 77 to reestablish engagement of 
guide bars 136, 137 and guide rails 70. As shown best in FIG. 7, such 
movement of magazine 52 causes pawl 142 to move along path 162 in 
serpentine slot 144 from base leg 152 through the exit arm 154 into the 
entry arm 150 of an adjacent Y-shaped passage. One-way gate 156 blocks 
return movement of pawl 142 into the first entry arm 150. 
Drive rod 140 is pushed in sideways direction 77 as pawl 142 is forced to 
move along path 162 to cause tubular shaft 92 to disengage the inlet head 
60 of the first embolus cartridge 56 and piston 82 to force most of the 
pressurized fluid 90 out of the space 88 in cylinder 78. As noted above, 
this discarded fluid is conducted through waste conduit 40 and deposited 
in waste fluid reservoir 29. As shown in FIG. 7, pawl 142 moves past a 
second one-way gate 164 pivotably appended to magazine 52 on its way to a 
new "home" position in the adjacent entry arm 150. (For example, pawl 142 
is shown in one of its home positions in FIG. 8.) It will be appreciated 
that this second one-way gate 164 blocks reentry of pawl 142 directly into 
exit arm 154 during a next cycle of operation. Also, it will be understood 
that movement of pawl 142 along path 162 will cause magazine 52 to move 
another increment of one-half step in forward direction 74 due to camming 
engagement of pawl 142 and camming surface 166 in exit arm 154. Now pawl 
142 has moved magazine 52 one full step along guide rails 70, 72 to 
complete one cycle of operation. 
A purge valve assembly 168 is provided on cylinder 78 to purge air from 
inside cylinder 78 prior to the first operation cycle of system 10. Purge 
valve assembly 168 includes a discharge conduit 170, a valve 172, and a 
biasing spring 174 in the discharge conduit 170. 
In another embodiment illustrated in FIG. 9, an alternative embolus 
discharge system 190 is shown to include a mechanical magazine advancing 
assembly 192 instead of the hydraulically actuated system shown in FIGS. 
1-8. Assembly 192 includes, for example, a rotatable handle 193 rotatably 
mounted in a side wall of the feeder housing and a screw 194 fixed to 
rotate with handle 193 and push against movable magazine 195. Handle 193 
can be rotated to rotate screw 194 and advance magazine 195 in direction 
191 in one step increments in the feeder housing. A spring-loaded detent 
assembly 196 can be provided as shown in FIG. 9 to engage a series of 
circumferentially spaced-apart notches in the underside of handle 193 to 
control the actual length of each incremental movement of magazine 195 in 
direction 191. Also, an extension 194a of screw 194 can be coupled to 
other manual or automatic rotating means (not shown) to control advance of 
magazine 195 in direction 191. It is within the scope of the present 
invention to use any suitable mechanical linkage configured to move 
magazine 195 incrementally in direction 191 to align the cartridges 56 in 
magazine 195 in an embolus-discharging position within feeder box 190. 
In still another embodiment illustrated in FIG. 13, an alternative embolus 
discharge system 290 is shown to include an assembly 192 (like the 
assembly shown in FIG. 9) for mechanically advancing magazine 295 along 
rails 70 inside feeder housing 280. Feeder housing 280 includes an inlet 
282 for receiving a guide wire 284 and an outlet 286 for receiving the 
guide wire 284 and an embolus 12 discharged from magazine 295. As in 
previous embodiments, magazine 295 includes a plurality of cartridges 56 
and each cartridge 56 is formed to include a hollow passageway containing 
a single embolus 12. Of course, magazine 295 could alternatively be moved 
inside feeder housing 280 manually or using other mechanical or electrical 
means. 
A conventional guide wire 284 is movable in direction 288 to enter inlet 
282 and the passageway of a cartridge 56 aligned with inlet 282. The 
embolus 12 can be expelled from cartridge 56 into catheter 16 in response 
to movement of guide wire 284 in direction 288 to engage embolus 12 and 
push it out of magazine 295 through outlet 286. It will be understood that 
the guide wire 284 could then be moved further in direction 288 to move 
expelled embolus 12 all the way through catheter 16 such that the embolus 
12 is expelled from catheter 16 and deposited at a destination outside of 
catheter 16. 
In yet another embodiment illustrated in FIG. 4, syringe means 300 is 
provided to generate a stream of pressurized fluid that is delivered into 
feeder assembly 14 through hose 314. Syringe means 300 includes a hollow 
barrel 302 having a nozzle 304 at one end and a handle 306 at the other 
end. A plunger 308 is inserted into the handle end of the barrel 302 as is 
movable therein to pressurize a predetermined volume of fluid 312 
contained in reservoir 310 therein and discharge that fluid 312 from the 
hollow barrel 302 through the nozzle 304. A hose assembly 314 
interconnects nozzle 304 of syringe means 300 and the inlet fitting 22 of 
feeder assembly 14 to conduct a stream of pressurized fluid discharged 
from the nozzle 304 into one of the embolus-containing cartridges provided 
in feeder assembly 14. This stream of pressurized fluid dislodges an 
embolus and discharges it into catheter 16 in the manner described above. 
A steerable and aimable guide catheter 196 of the type available from 
Catheter Research, Inc. of Indianapolis, Ind. can be used to position 
introducer catheter 16 in a selected position in a body as shown, for 
example, in FIGS. 10-12. Guide catheter 196 includes an inlet fitting 197 
at its proximal end and an outlet opening 198 at its distal end as shown 
best in FIG. 12. A control unit 199 is connected by wire harness 200 to a 
socket 202 provided on guide catheter 196. Control unit 199 provides 
remote control means to permit a surgeon to steer guide catheter 196 
through body passages and aim the outlet opening 198 at selected targets 
within the body undergoing surgery. 
Reference is hereby made to U.S. Pat. Nos. 4,543,090; 4,601,705; and 
4,758,222 for descriptions of the structure, function, and operation of 
suitable steerable and aimable catheters. It will be appreciated that a 
variety of sizes, shapes, and kinds of guide catheters and guide wires 
could be used to guide introducer catheter 16 to its destination in a body 
and that, in certain circumstances, introducer catheter 16 could be moved 
in a body to reach its target site without using any other catheter to 
guide it. It should also be understood that a steerable and aimable guide 
catheter could be used by itself to deliver an embolus to a destination in 
a body without using any separate introducer catheter. 
Delivery of an embolus 12 to a target site in a blood vessel using 
embolus-delivery system 10 is illustrated in FIGS. 10 and 11. The distal 
end 198 of guide catheter 196 inserted through a venotomy into a body is 
advanced into a main blood vessel 204 having a pair of collateral blood 
vessels 206, 208 branching out from the main blood vessel 204 Collateral 
vessel 208 contains a coil embolus 12 that is wedged against the interior 
wall 210 of collateral vessel 208 to anchor the coiled embolus 12 in place 
so that blood begins to clot and form a vessel-occluding thrombus (not 
shown) around coil embolus 12. 
The guide catheter 196 is maneuvered using control unit 199 to insert the 
distal tip 212 of the introducer catheter 16 into the open mouth of the 
unoccluded collateral vessel 206 so that the distal tip 212 is aimed 
toward a target site 214 therein. The steerable and aimable guide catheter 
196 is inserted into the collateral vessel 206 as well. Illustratively, a 
temperature-activated memory element 216 made of a shape-memory alloy is 
connected to a lead wire 218 and heated using control unit 199 to move the 
distal end of guide catheter 196 to assume the upwardly curved shape shown 
in FIGS. 10 and 11. 
The introducer catheter 16 extends through the lumen of guide catheter 196 
and is movable axially therein until a clamp (not shown) is tightened to 
grip the outer surface of introducer catheter 16 and prevent relative 
movement of introducer catheter 16 inside the lumen of guide catheter 196. 
Once introducer catheter 16 has been maneuvered to enter the mouth of 
collateral vessel 206 as shown in FIG. 10, then the clamp can be loosened 
to permit the surgeon to push the introducer catheter 16 forward so that 
its distal tip 212 extends a short distance out of the lumen of guide 
catheter 196 and into the collateral vessel 206 and faces target site 214. 
At this point, the introducer catheter 16 is locked by tightening the 
clamp to prevent movement of introducer catheter 16 relative to guide 
catheter 196. 
Desirably, the inner diameter of the lumen in guide catheter 196 is large 
enough to contain an angioscope 220 (shown in FIG. 12) in addition to the 
introducer catheter 16. The angioscope 220 can be used to permit the 
surgeon to view the interior regions of the main and collateral blood 
vessels as the guide catheter is steered to reach the collateral vessel 
206 sought to be occluded. 
Once a surgeon is satisfied that the introducer catheter 16 is in a 
collateral vessel and aimed properly at the target site in the collateral 
vessel, the surgeon is free to use the actuator means 30 to inject a slug 
of fluid into the cartridge 56 at a rate sufficient to dislodge the 
embolus 12 from its fixed position in the cartridge passageway 58 and 
propel the embolus 12 into and through the lumen of the introducer 
catheter 16. The coil embolus 12 remains in a somewhat uncoiled and 
straightened packed shape as it travels through the lumen of the 
introducer catheter 16 and reforms to its helical coiled shape as soon as 
it emerges from the distal tip of the introducer catheter 16. Using this 
technique, coil emboli can be delivered to a target site in a collateral 
vessel using a pressurized fluid such as biocompatible saline or the like 
without resort to use of a guide wire to move a coil embolus 12 either 
into or through an introducer catheter 16. Of course, as shown in 
embodiment of FIG. 13, a guide wire 284 or the like could be used instead 
of pressurized fluid to discharge an embolus 12 from cartridge passageway 
58 either into or through introducer catheter 16. 
One suitable application of the method and apparatus of the present 
invention is to perform a medical procedure known as a vein bypass of 
femoro-popliteal, femoro-tibial, or femoro-pedal arteries. This surgery 
can reconfigure a vein to function as an artery so as to replace one or 
more occluded, diseased, or otherwise malfunctioning arteries. 
In severe lower limb (leg) ischemia requiring surgery, the superficial 
femoral and proximal popliteal arteries are generally occluded. As an 
alternative to limb amputation, it is known to suture the proximal end of 
the saphenous vein end-to-side on the distal common femoral artery and the 
distal end of the graft end-to-side on the distal popliteal artery. 
Typically, it is necessary to "fillet" the leg by making a long incision 
along the length of the leg to expose and prepare the vein undergoing 
reconfiguration and its collateral blood vessels (side branches). It is 
then typically necessary to ligate the numerous side branches of the vein. 
It will be understood that conventional surgical procedures of this type 
are complex and difficult and may result in a lot of substantial incisions 
made into the body of the patient. Also, the healing process of patients 
treated using the conventional procedures are often long and impaired 
because many of the patients are old, diabetic, obese, or a combination 
thereof. 
Embolus delivery system 10, 190, or 290 can be used in surgery to complete 
a vein bypass of femoro-popliteal, femoro-tibial, or femoro-pedal 
arteries. Essentially, introducer catheter 16 can be guided into the lumen 
of a selected vein and its side branches through a small incision made in 
the leg by itself or using the guide catheter. The delivery system 10, 
190, or 290 is operated to deliver an occlusion coil or other embolus 12 
to a destination in the side branch. This procedure can be repeated for 
each side branch of the vein. Advantageously, this type of embolization 
procedure can be used to occlude all of the side branches of a vein 
without necessarily filleting the leg to expose the entire vein and 
surgically ligating each side branch of the vein. Visualization of the 
vein and its side branches can be accomplished by angioscopy. Also, 
ultrasound techniques can be used to monitor the progress of this new 
embolization technique. 
A portion of the vein bypass procedure accomplished using the embolus 
delivery system 10, 190, or 290 is illustrated in FIG. 12. For example, 
such a procedure involves the steps described in the following paragraphs. 
It will be understood that the use of system 10, 190, or 290 is not 
limited to surgical procedures on legs; rather system 10, 190, or 290 has 
great utility in surgical procedures involving other body parts and also 
in other non-surgical or non-medical procedures where it is advantageous 
to occlude a vessel. 
Referring to FIG. 12, a first small incision 230 is made to open vein 232 
in an upper portion of leg 234 near the groin area and a second small 
incision 236 is made in a lower portion of leg 234 near the ankle. 
Irrigation fluid is introduced from irrigation fluid supply 237 into vein 
232 through one of the incisions 230 or 236 (or alternatively through a 
nearby ancillary incision (not shown)) to flush all blood out of vein 232 
through the other of the incisions 230 or 236. An actuator 241 is provided 
to permit the surgeon to actuate irrigation fluid supply 237 periodically. 
For example, a foot pedal-actuated device (not shown) can be used as an 
actuator 241 to permit the surgeon to irrigate vein 232 and its side 
branches prior to and/or after embolization. Blood typically oozes into 
vein 232 and the surgeon must clear the vein using the irrigation fluid 
during embolization. A waste irrigation fluid reservoir 239 can be 
provided to collect waste irrigation fluid passed through the body. 
Guide catheter 196 is inserted into vein 232 through first incision 230 and 
moved therein so that an angioscope 220 deployed in guide catheter 196 can 
be used to observe each of the randomly spaced one-way check valves 238 
situated in vein 232. Typically, four to six of these check valves 238 are 
formed in the length of saphenous vein 232 used to perform bypass grafts 
in a human leg. These one-way check valves 238 are configured to allow 
blood to flow through vein 232 in a direction toward the heart and prevent 
blood flow in the opposite direction. Initially, the angioscope 220 is 
moved through vein 232 using guide catheter 196 to a position allowing the 
surgeon to observe the check valve 238 farthest from the foot. 
An apparatus 240 known as a valvulotome is then inserted into the vein 232 
through the second incision 236 and advanced therein in a direction away 
from the foot to contact the one-way check valve 238 observed using the 
angioscope 220. This apparatus 240 can be used in the conventional way to 
render each check valve 238 in vein 232 incompetent so that fluid can now 
flow through vein 232 in either direction. Essentially, this apparatus 240 
is used to cut and disable each of the check valves 238 in sequence while 
the valves 238 are being observed using the angioscope 220 deployed in 
guide catheter 196. 
As shown in FIG. 12, apparatus 240 and angioscope 220 have already 
cooperated to disable the check valve 238a in vein 232 that is farthest 
from the foot and have now moved to a position already to cut and disable 
the next check valve 238b. Check valve 238c has not yet been disabled. 
Next, the guide catheter 196 and introducer catheter 16 are used in the 
manner described above to occlude in sequence each of the side branches 
(collateral vessels) 242 of vein 232. The vein 232 is then connected to 
the adjacent occluded or otherwise disabled artery 244 at the top of the 
artery (through first incision 230) and at the bottom of the artery 
(through second incision 236) to cause blood to flow through vein 232 
instead of through the occluded or diseased segment of the artery 244 so 
that the vein 232 is transformed into a new artery. The angioscope 220 in 
guide catheter 196 can be used to inspect the transformed vein 232 to 
ensure that it will function properly as an artery in its reconfigured 
state. 
Advantageously, the embolus delivery system 10, 190, or 290 can be used to 
assist in reconfiguring a vein to function as an artery after making only 
two small incisions in the leg to be treated It will be appreciated that 
vein reconfiguration surgery using embolus delivery system 10, 190, or 290 
is much less invasive than many known surgical procedures which require a 
long incision to be made along the length of the leg and each side branch 
of the exposed vein to be ligated by hand. It will be appreciated that the 
human body has in place multiple collateral veins in the leg, both 
functional and non-functional, which will automatically become functional 
and compensate the vein. 
Although the invention has been described and defined in detail with 
reference to certain preferred embodiments, variations and modifications 
exist within the scope and spirit of the invention as described and 
defined in the following claims.