WO2000067661A2 - Heart valve and apparatus for replacement thereof, blood vessel leak detector and temporary pacemaker lead - Google Patents

Abstract

Apparatus and methods for replacing a heart valve within a vessel (10). The apparatus includes a replacement heart valve (20) and a plurality of commisure stabilizers (64, 66, 68) temporarily connected to the commisures of the heart valve (20) in a removable manner. A cannulating device (320) which, in a first embodiment, includes a cannula (324), a hub portion, and a retaining member (332) extending from the hub portion. In a second embodiment, a clamp (348) is coupled with the hub portion (350) and may be moved between open and closed positions to retain the vessel (342) in a sealed condition on the cannula. A temporary pacemaker lead including a wire (434) having an electrically conductive portion, a first connector portion (438) on the wire, and an electrode (430) having a second connector portion (436).

Description

HEART VALVE AND APPARATUS FOR REPLACEMENT THEREOF, BLOOD VESSEL LEAK DETECTOR AND TEMPORARY PACEMAKER LEAD

Background of the Invention

A popular option for aortic valve replacement is to retain the

native aortic root and the normal coronary artery attachments and secure

the replacement prosthesis inside the patient's own aorta. With this

procedure, only the valve is replaced and not the entire root. It is

unnecessary to re-attach the coronary arteries and, should repeat surgery be

necessary, a surgeon must only replace the valve and not an entire section

of the aorta. When a surgeon replaces the aortic valve in this manner, the

patient is first placed on a heart-lung machine and the section of the aorta

having the aortic valve is clamped off to allow access. That section of the

aorta is therefore collapsed and unpressurized leaving a pressurized section

connected to the heart-lung machine. The unpressurized section of aorta is

then opened and the diseased valve is removed in its entirety, including

careful removal of calcium deposits within the aorta and annulus. The aorta

and sinotubular junction are then sized and the surgeon prepares the

appropriate replacement valve. The surgeon then sutures the inflow or

annular end of the replacement valve into the inside of the aorta. When

these sutures are drawn tight, the valve is pulled inside the aorta when

approximately 20 sutures are then applied around the annular end. The commisures of the replacement valve, which extend from the annular end,

may or may not need to be affixed to the aorta as discussed below.

Two major types of prosthetic or replacement heart valves

exist. The first general type of valve is a mechanical prosthesis which

includes commisures that are self-supporting and do not need to be affixed

to the aortic wall. Mechanical prostheses are generally formed entirely of

artificial material, such as carbon fiber, titanium, dacron and teflon. While

these mechanical prostheses are durable, relatively quick to implant and

generally easy to manipulate during surgery, they also have certain

disadvantages. For example, due to the artificial materials used in their

construction, blood clots can form on the valve and subsequently cause

valve failure. If the clot dislodges from the valve, the clot can lodge in a

downstream vessel and cause stroke or organ ischemia. For these reasons,

patients with mechanical heart valves must take anticoagulants for the rest

of their lives. Anticoagulants bring about their own complications in some

patients, including internal bleeding or other side effects.

The second major type of prosthetic or replacement heart valve

is a biologic valve. This category includes valves harvested from human

cadavers, i.e., allografts or homografts, or animal tissue generally harvested

from cows and pigs. More recently, there has been increasing effort to

develop synthetic biologically compatible materials to substitute for these

natural tissues. Among their advantages, biologic prostheses generally do

not require lifelong anticoagulation as they do not often lead to clot

formation. These valves are provided in stented or unstented forms. A stented valve includes a permanent, rigid frame for supporting the valve,

including the commisures, during and after implantation. The frames can

take the form of a wire or other metal framework or a plastic frame encased

within a flexible fabric covering. Unstented valves do not have built-in

commisure support so surgeons must use their skill and best judgement to

determine the optimal site of implantation inside the patient's native aorta

to maintain valve competence. When securing the valve commisures,

obstruction of the patient's native coronary arteries must be avoided or

myocardial infarction may result.

There are many limitations to procedures utilizing permanently

stented biologic replacement valves. First, allografts (human cadaver donor

valves) are not generally available with permanent frames or stents.

Second, the frames or stents can take up valuable space inside the aorta

such that there is a narrowing at the site of valve implantation. This

narrowing leads to pressure gradients and increased loads on the left

ventricle and, therefore, increased incidence of hypertrophy and reduced

patient survival. The frame includes artificial materials which can increase

the risk of new infection or perpetuate an existing infection. It is also very

important to realize that although the permanent frames or stents guarantee

alignment of the commisures, they cause very high stresses on the

commisures when the valve cusps move between open and closed

positions. A patient's natural commisures are not placed under significant

strain during opening and closing of the valve due to the natural resilience

of the aorta. On the other hand, artificially mounted valves place the commisures under strain during operation of the valve due to the rigid

materials of the frame. Over time, the valve cusps tend to decay under this

strain and manifest calcification and tears which can lead to valve failure.

In many situations, biologic replacement heart valves are

preferred in the unstented form due to the drawbacks mentioned above.

Such valves are more resistant to infection when implanted free of any

foreign material attachments, such as stents or frames. Also, the heart

valve is more efficient when used without a stent. Efficiency refers to the

pressure gradient across the valve during use. Natural human valves have

almost no pressure gradient. When a natural heart valve is replaced by a

biologic heart valve with a low pressure gradient, complications such as

hypertrophy arise less often and result in improved patient survival.

Despite the known advantages of using biologic prosthetic

heart valves without artificial supporting devices such as permanent stents

or frames, relatively few surgeons employ this surgical technique due to its

high level of difficulty. When unsupported or unstented by artificial

devices, such as permanent stents, biologic replacement heart valves have

a flimsy, soft and flexible nature. That is, the commisures of the heart

valve do not support themselves in the proper orientation for implantation.

For these reasons, it is very difficult to secure the commisures properly into

place. In this regard, the surgeon must generally suture the individual

commisures of the heart valve in exactly the proper orientation to allow the

valve to fully and properly function. During valve replacement surgery, an L-shaped retractor is

placed inside the aorta to pull it open for access purposes. While this

provides exposure, it distorts the aorta and may give the surgeon an

incorrect impression of the correct valve position. Next, and especially with

regard to unstented biologic valve procedures, the surgeon must guarantee

that the commisures pass straight up the aorta at roughly right angles to

the plane of the annulus. There is very little technology to help the surgeon

correctly place the stentless replacement valve. To help confirm that the

leaflets are correctly spaced at 1 20° apart, surgeons may use a disc having

markings 1 20° apart. The surgeon can use this to roughly estimate the

spacing by placing it near the distal ends of the commisures. However, this

provides only a rough guide. For example, it is possible to equally space the

commisures at the upper end and still have a valve placed in a skewed

position. Finally, the aorta is not a straight tube at the surgical site, but

instead flares outward at the surgical site. The valve must conform to the

flare of the aorta at this location. Once the surgeon has completed an

inspection for these three elements, i.e., correct spacing at approximately

1 20° between the commisures, correct perpendicular position of the

commisures relative to the annulus plane, and appropriate conformation to

the flare of the aorta, the surgeon must suture the commisures to the wall

of the aorta. As this is done, it is necessary to make sure there is no

encroachment on the ostia or origins of the coronary arteries. After the

valve commisures are attached to the aorta and proper orientation and

positioning is confirmed, the surgeon closes the aorta. Following surgery, there is a risk that the aorta will dilate at

the sinotubular junction months or years later and draw the valve

commisures and attached cusps apart from each other. This will cause

insufficiency and failure due to leakage through the valve. There is a further

need for methods to ensure that late enlargement of the sinotubular junction

does not necessitate reoperation for late valve insufficiency and failure.

In general, there is an increasing need for devices which

improve the efficiency and reliability of implanting replacement heart valves.

In conjunction with this, there is a need to improve these procedures so

that all surgeons, not just those with the highest skill levels, can implant

heart valves with superior results.

Blood vessels must frequently be cannulated with fine tubes,

i.e., cannulas, to allow injection of fluids into the vessels. When the

vessels are large enough, such as several millimeters in diameter, relatively

large and rigid cannulas may be placed inside the vessel. A tie is then

typically secured around the vessel and the inserted cannula to prevent to

vessel from sliding off. These larger, more rigid cannulas have a

circumferential ridge behind which the tie is formed to help prevent the

vessel from sliding off the cannula. This process is somewhat cumbersome

as it requires cannulation, stabilizing of the cannula within the vessel, and

finally tying of a suture around the vessel and cannula. As the suture is

being tied, the vessel can slide off the cannula and, therefore, an assistant

must be used to hold the vessel and cannula stable. When vessels are very small, such as in the range of 1 to 2

millimeters, very small cannulas 1 0 must be inserted into the vessel 1 2

(Figure 1 4) . The walls of these small cannulas are very thin so that there is

space for an infusion lumen 1 4. Also, there is no increased diameter

portion or ridge on the cannula 1 0. For this reason, it is more difficult to

hold the vessel 1 2 in place with a suture 1 6. The suture 1 6 must be tied

quite tightly to hold the vessel 1 2 on the cannula 1 0. As the cannula 1 0 is

thin, this frequently occludes the lumen 1 4 by crushing the cannula 1 0, as

shown in Figure 1 , and thereby prevents fluid flow. If the suture is tied too

loosely, the vessel frequently slides off the cannula.

In view of these and other problems in this area, it would be

desirable to provide a device that simplifies the attachment of a cannula to

a vessel. Additional advantages would be obtained by eliminating the need

for suture tying, increasing the speed of the procedure, and reducing the

problems related to cannulating small vessels.

Temporary pacing wires are placed at almost every cardiac

operation, but there have been no advances for many years. There are a

number of current temporary pacemaker leads available for pacing after

cardiac surgery. Leads (in reality a bare segment of an insulated wire) can

be attached to the heart by a suture which holds the exposed wire in

contact with the surface of the heart. When the lead is removed it is

simply pulled out, breaking the stitch. The other way to attach the

temporary lead is to attach a needle to the end of it and then pass the

needle through the heart with a partial thickness bight. The needle is then cut off the wire. Exposed wire is left in contact with the heart. The wire is

removed by simply pulling it out. The wire often has a series of bends or a

small amount of attached plastic material to increase the friction to keep it

from coming out.

There are a number of problems with these two options.

Referring to Figure 20, the suture method requires that the surgeon place a

stitch in the form of a loop 51 0 and then feed the wire 51 2 through the

loop 51 0 and tie it. This is somewhat tedious, especially on a beating heart

51 4. The wire 51 2 under the suture loop to is often easily removed by

even a minimum of pull on the wire and it frequently has to be replaced.

When a secure wire 51 2 is removed, there is the risk that the surface of the

heart 51 4 will be torn as the suture snaps or that the suture does not snap

and a small divot 51 6 of myocardium is pulled off as also shown in Figure

20. This can lead to bleeding which can be fatal.

The second system is shown in Figure 21 whereby a wire

suture 520 is passed through the heart 51 4 is quicker. The wire suture

520 must be passed and the wire cut off as shown at cut 522 located

above a flared stop portion 524. Flared stop portion 524 is designed to

prevent the wire from being pulled back through heart 51 4. However,

during insertion the wire 520 frequently causes bleeding and the bleeders

must be sutured. When the wire 520 is removed, there is a risk that the

friction of the wire removal combined with the drag of the flared portion

524 will result in a piece of myocardium being torn, again resulting in bleeding. Also, the wire 520 frequently becomes dislodged before the

chest is closed and it has to be replaced.

The prior art does not demonstrate the concept of leaving a

small permanent electrode in place and separating this from the wire. This

concept is very important because on removal the risk of bleeding comes

when the wire is pulled through the heart muscle or when the suture must

snap.

In short, current methods are somewhat tedious, can result in

bleeding at insertion and removal and the leads frequently become dislodged

requiring complete reinsertion. It would be very useful to ease the insertion,

permit reattachment should the wire become dislodged and reduce the risk

of bleeding when the wire is removed.

Summary of the Invention

The present invention generally provides apparatus directed at

solving problems, such as those described above, with regard to replacing a

heart valve within a vessel. In one general aspect, the invention provides a

replacement heart valve and a plurality of temporary commisure stabilizers.

More particularly, the replacement heart valve will generally have an annular

base and a plurality of spaced apart commisures extending from the annular

base at spaced apart positions. The valve may be formed of animal tissue,

such as valves harvested from pigs, cows or human donors. Optionally, the

valve may be formed from synthetic, biologically compatible material. With

the typical aortic valve replacement, there will be three commisures spaced roughly 1 20° apart. Each commisure includes a proximal end connected

with the annular base and an opposite distal end. The plurality of

commisure stabilizers are connected to the commisures in a removable

manner. These commisure stabilizers position and stabilize the commisures

of the replacement heart valve as a surgeon secures the replacement heart

valve in place within the vessel. The commisure stabilizers, in the instance

of an aortic valve replacement, positively orient the commisures at the 1 20°

spaced apart positions and generally perpendicular to a plane which

contains the annular base of the heart valve.

Following securement of the replacement heart valve within

the vessel, the commisure stabilizers are preferably removed to avert the

various disadvantages of permanent stents or frames. However, there may

be situations in which a particular surgeon desires to leave one or more of

the commisure stabilizers in place and the invention advantageously

provides for this option as well. In the preferred embodiment, the

commisure stabilizers are connected together at spaced apart distal

positions, for example, by a generally annular member. Each commisure

stabilizer preferably comprises at least one elongate member attachable in a

manner allowing removal from the distal end of the respective commisure

following implantation of the heart valve.

The replacement heart valve can include respective receiving

elements for the commisure stabilizers. These may comprise pockets, loops

or other structure adapted to receive the stabilizers in a manner allowing

removal by a surgeon at the distal end of the commisures after implantation. The commisure stabilizers may also be removably affixed to

other supporting structure, such as the generally annular member described

above. This, for example, will allow the surgeon to remove the annular

member or other supporting structure for easier suturing access, while at

least temporarily leaving the commisure stabilizers in place for positioning

purposes. After suturing and/or other securement of the valve, the

commisure stabilizers would be removable to achieve the full advantages of

this invention.

Each commisure stabilizer may further comprise at least two

spaced apart elongate members or, more preferably, three elongate

members. One or more of these members may curve or flare outwardly in a

lengthwise direction to urge the commisures of the replacement heart valve

against the flared interior wall of the vessel. The outer elongate members

may also angle or curve away from the central elongate member to extend

along opposite edge portions of the respective commisures.

In another aspect of the invention, the positioning and

stabilizing device may be formed in a collapsible manner allowing insertion

into the vessel in a collapsed state and subsequent expansion for

positioning and stabilizing the valve commisures during securement of the

valve within the vessel. For example, the positioning and stabilizing device

may be at least partially formed of a shape memory material allowing the

positioning device to be collapsed and expanded as necessary. This aspect

of the invention may also be practiced in other manners, such as through

the use of hinged or otherwise collapsible and expandible structures. ln accordance with another aspect of the invention, a flexible

material may connect the distal ends of the three commisures. This will

prevent the commisures from moving radially apart due to late sinotubular

enlargement. This material may also be secured to the internal wall of the

vessel to help prevent the need for reoperation due to the complications of

late enlargement of the sinotubular junction as described above.

A method of implanting a replacement heart valve in

accordance with the invention includes inserting the replacement heart

valve into a patient, connecting at least one commisure stabilizer to each of

the commisures of the replacement heart valve either before or after

inserting the replacement heart valve, securing the replacement heart valve

within the patient using the commisure stabilizers to orient the commisures

of the replacement heart valve, and removing one or more of the commisure

stabilizers from the patient leaving the secured replacement heart valve in

place. Other methods of utilizing apparatus as described herein are also

within the scope of this invention as will be apparent.

According to another aspect of the invention, a cannula is

placed in a vessel and tied with a suture tight enough to prevent leaking

between the vessel and the cannula, but loose enough to prevent occluding

the lumen of the cannula. A hub of the cannula contains a friction lock so

that the suture which holds the vessel on the cannula may be retained by

the friction lock thereby preventing the vessel from sliding off the cannula.

The friction lock may be substituted with other retaining members for the

suture. ln another embodiment, tying a suture to the vessel is

eliminated, for example, through the use of a clamp having movable jaws.

The vessel engaging portions of the jaws may be covered with a soft

material, such as foam, for protecting the vessel. The jaws may be moved

between opened and closed positions. The cannula is inserted in the vessel

and the jaws are moved over the vessel containing the cannula. The jaws

are then moved from the open position to the closed position. This seals

the vessel to the cannula and prevents the vessel from sliding off the

cannula. This embodiment is presently preferred because it is quicker and

applies to small or large vessels. There is also no need for a ridge or area of

increased diameter on the cannula. Also, fine cannulas would not be

crushed and no assistant is necessary as one hand may hold the cannula

and vessel together, while the other hand may be used to open and close

the jaws. Finally, the device would be inexpensive and simple to

manufacture.

The invention further contemplates a temporary pacing wire

system which eliminates the risk of bleeding from the heart when the lead

is attached. It is another object of this invention to demonstrate a

temporary pacing lead which can be removed from the heart without the

risk of bleeding from the heart. It is another object of this invention to

demonstrate a temporary pacing lead which can be re-attached should it be

inadvertently removed from the heart before the incision is closed. It is a

further object of this invention to describe a temporary pacing system lead

that can be quickly attached to the heart without need for suture. An electrode is permanently attached to the heart. The

electrode can be a very tiny piece of metal, such as a clip. Releasably

attached to the electrode is a wire which can be removed from the

electrode and reattached to it. The electrode does not cause bleeding on

attachment to the heart. The electrode is not removed from the heart, so

that when the wire is pulled there is no ripping of the heart tissue but only

separation of the electrode from the wire. Should the wire be inadvertently

removed from the electrode after it is attached it is possible to quickly

reattach it.

The electrode could be sutured to the heart. More simply and

more efficient would be a mechanically applied electrode clip. Clips can be

applied in seconds and do not require suture. The clip could take the form

of a current vessel ligation clip. Alternatively, specially modified clips for

attachment could include an extension attached to a hemoclip which

impales the heart. Another variation could include a clip that looks like a

scorpion's pincer.

The attachment of the wire to the clip can be accomplished in

a number of ways. The clip could have a small loop through which a loop

of preformed pacing wire is attached. The loop on the pacing wire could

open to ensure easy removal. The clip could have two parallel rabbit ear¬

like attachments for holding the wire in place. Many other attachments

would be possible to configure.

There are multiple advantages to the invention. For example,

no suturing is required with a clip-on electrode. The clip is attached by simply squeezing the handle of a small tool. The wire is preattached to the

clip so that there is an instantly functioning pacemaker with no additional

steps.

The pacing wire is attached reversibly to the electrode clip so

that it can be easily pulled out without the risk of tearing myocardium. This

is due to the fact that the clip is permanently attached to the heart and the

wire slips away from or disengages the clip. There would be no direct

dislodgement from the heart.

Should the wire become accidently dislodged during surgery, it

can be easily reattached.

The product is easy to manufacture, package and distribute as

it may take the form of existing hemoclip products.

These and other objects, advantages, and features of the

invention will become more readily apparent to those of ordinary skill in the

art upon review of the following detailed description of the preferred

embodiments, taken in conjunction with the accompanying drawings and as

more generally set forth in the appended claims.

Brief Description of the Drawings

Figure 1 is a partially fragmented perspective view of an aorta

undergoing a valve replacement operation with an unstented biologic

replacement valve in the process of insertion;

Figure 2 is a view similar to Fig. 1 , but showing the initial

removable attachment of a positioning and stabilizing device having commisure stabilizers constructed in accordance with one embodiment of

the invention;

Figure 3 is a perspective view similar to Fig. 2, but showing

the positioning and stabilizing device fully inserted and the properly

positioned and stabilized commisures being sutured in place;

Figure 4 is a perspective view similar to Fig. 3, but showing

the fully implanted heart valve;

Figure 4A is a cross sectional view taken along line 4A-4A of

Fig. 4;

Figure 5 is a perspective view showing an alternative

embodiment of a positioning and stabilizing device being removed from a

replacement heart valve following implantation;

Figure 6 is a perspective view of another alternative

positioning and stabilizing device constructed in accordance with the

invention;

Figure 6A is a cross sectional view taken along line 6A-6A of

Fig. 6;

Figure 7 is a perspective view of another alternative

embodiment of a positioning and stabilizing device;

Figures 8A and 8B are perspective views of another alternative

positioning and stabilizing device respectively shown in collapsed and

expanded conditions; Figure 9 is a perspective view of an alternative replacement

heart valve and removable positioning and stabilizing device constructed in

accordance with the invention;

Figure 9A is a perspective view of the apparatus shown in Fig.

9 with the positioning and stabilizing device removed;

Figure 9B is a fragmented and enlarged view of the positioning

and stabilizing device of Figs. 9 and 9A showing the separable parts

thereof;

Figure 1 0 is a perspective view of another alternative

replacement heart valve and removable positioning and stabilizing device

constructed in accordance with the invention;

Figure 1 1 is a perspective view of an aortic expansion device

constructed in accordance with the invention;

Figure 1 2 is a perspective view of an alternative aortic

expansion device;

Figure 1 3A is a top view of the expansion device illustrated in

Figure 1 2, but shown in a collapsed condition; and

Figure 1 3B is a top view of the expansion device shown in

Figure 1 2 in an expanded condition.

Figure 1 4 is a fragmented, partial cross sectional view of a

prior art cannulating device.

Figure 1 5 is a fragmented, partial cross sectional view of a

cannulating device constructed according to one embodiment of the

invention. Figure 1 5A is an enlarged view of encircled portion 1 5A of

Figure 1 5.

Figure 1 6 is a fragmented, partial cross sectional view of a

cannulating device constructed in accordance with another embodiment of

the invention.

Figure 1 7 is a fragmented, elevational view of the device

shown in Figure 1 6, but showing an elastic ligature forcing a pair of

clamping jaws into a closed position.

Figure 1 8 is an elevational view of an alternative embodiment

similar to Figure 1 7, but showing the ligature in a disengaged position

holding the jaws in an open position.

Figure 1 9 is a cross sectional view taken along line 1 9-1 9 of

Figure 1 7.

Figure 20 is an elevational view showing a prior art method of

attaching and removing a temporary pacing wire to the heart of a patient;

Figure 21 is an elevational view similar to Figure 20, but

showing an alternative prior art method of attaching a temporary pacing

wire to the heart;

Figure 22 is a perspective view of a temporary pacemaker lead

constructed in accordance with one embodiment of the invention;

Figure 23 is a perspective view showing the temporary

pacemaker lead of Figure 22 attached to the heart of a patient;

Figure 24 is a perspective view of one alternative embodiment

of the invention; Figure 25 is a side elevational view of the embodiment shown

in Figure 24; and

Figure 26 is a perspective view of another alternative

embodiment of the invention.

Detailed Description of the Preferred Embodiments

Figure 1 illustrates an aorta 1 0 which a surgeon has incised to

create an opening 1 2 after a patient has been placed on a heart-lung

machine. One or more retractors 1 4 may be used by assistants to gain

access to opening 1 2. Aorta 1 0 may be partially incised as shown or it

may be fully incised across its transverse dimension. During this procedure,

the patient's heart 1 6, disposed below the surgical site, is normally in an

arrested state due to the use of the heart-lung bypass machine and

cardioplegia.

An unstented replacement valve 20 is further shown within

aorta 1 0 in an initial flimsy, unsupported condition. In this case, a fabric

covering 22 is stitched on the outside of the biologic tissue 24, which may

be human or other animal tissue or synthetic material. Replacement valve

20 comprises typically three commisures 26, 28, 30 extending from an

annular base 32. Replacement valve 20 has been inserted within aorta 1 0

such that annular base 32 is disposed at the annulus 34 of aorta 1 0.

Conventional sutures 36 may be used as shown to pull replacement valve

20 within aorta 1 0 until it resides on annulus 34 in a known manner. As further shown in Figure 4A, a plurality of sutures 54 are

typically placed around the annular base 32 and into annulus 34.

Replacement valve 20 must be disposed within aorta 1 0 so as not to

occlude orifices 38, 40 communicating with the left and right coronary

arteries (Figure 2) . As additionally shown in Figure 4A, the typical aortic

replacement valve includes three cusps 42, 44, 46, respectively connected

with the three commisures 26, 28, 30 for movement between open and

closed positions as the heart beats to pump blood into the aorta. Sealing

lines of contact 48, 50, 52 are formed between the respective cusps 42,

44, 46. To maintain an effective seal along lines 48, 50, 52, commisures

26, 28, 30 must be positioned and secured within aorta 1 0 in a precise

manner. In this regard, each commisure should preferably extend in a

relatively perpendicular, non-skewed manner along the interior aortic wall

1 0a, and in a manner that is essentially perpendicular to annular base 32.

If this is not done, strain will be placed on commisures 26, 28, 30 and an

effective seal between cusps 42, 44, 46 may eventually be lost. Undue

strain on commisures 26, 28, 30 can cause decay and calcification and

eventually lead to valve failure and either death or a second surgical

operation.

Figures 2 and 3 illustrate one embodiment of a positioning and

stabilizing device 60 constructed in accordance with the invention.

Generally, positioning and stabilizing device 60 may be used in a temporary

manner while securing commisures 26, 28, 30 to aortic wall 1 0a.

Positioning and stabilizing device 60, in this embodiment, includes an annular portion 62 connected with a plurality of stabilizers 64, 66, 68, each

taking the form of a single elongate member. Each stabilizer 64, 66, 68

preferably bows outwardly along its length so as to generally conform to a

flared region 70 of the aortic root. As one of many possible temporary

securement methods, each stabilizer 64, 66, 68 is slipped between fabric

covering 22 and biologic tissue 24 of replacement valve 20. In the case of

a valve which does not have a fabric covering, other securing structure

such as suture loops, hooks, etc., may be used to attach stabilizers 64, 66,

68. This temporary connection may be made before replacement valve 20

is inserted into aorta 1 0 or after valve 20 is inserted within aorta 1 0. In the

preferred embodiments, assembly of a positioning and stabilizing device and

replacement valve, such as device 60 and valve 20, is felt to be best

accomplished prior to surgery to allow for insertion as a unit. As shown in

Figure 3, once replacement valve 20 and positioning and stabilizing device

60 have been secured within aorta 1 0, with stitches 54 already placed at

annulus 34, suturing of commisures 26, 28, 30 can begin. This may be

accomplished using a typical needle 72 and suturing thread 74 manipulated

by a gripping implement 76. The surgeon places sutures 78 in this manner

along the entire periphery of each commisure 26, 28, 30. It will be

appreciated that other manners of securing replacement valve 20 to aorta

1 0 may be used in accordance with the invention and, for example, include

gluing, stapling or other mechanical fasteners. Figure 4 illustrates the

completely secured replacement valve 20 implanted within aorta 10. It will

be appreciated that, in this embodiment, once positioning and stabilizing device 60 has been removed from the pockets formed between fabric

covering 22 and biologic tissue 24, the distal ends 26a, 28a 30a may be

stitched to the aortic wall 10a.

Figure 5 illustrates one alternative embodiment of a

replacement valve 20' useful in accordance with the invention.

Replacement valve 20 includes pockets 80 on the outside of each

commisure 26, 28, 30 for receipt of an alternative positioning and

stabilizing device 90. Like the first embodiment, positioning and stabilizing

device 90 can include an annular portion 92 and a plurality of three

stabilizers 94, 96, 98. In this embodiment, each stabilizer further

comprises multiple elongate members adapted to be removably inserted

within pockets 80. More specifically, each stabilizer 94, 96, 98 comprises

respective elongate members 94a-c, 96a-c and 98a-c. As will be

appreciated from stabilizer 96, outer elongate members 96a, 96c curve

outwardly from the middle elongate member 96b. In this manner, outer

members 96a, 96c extend within respective pockets 80 along the outer

curved edges 28b, 28c of commisure 28. The remaining stabilizers 94, 98

function in a similar manner. It will be further appreciated that each

stabilizer 94, 96, 98 bows outwardly, as in the first embodiment, to

conform to the flare 70 at the aortic root. Stabilizers 94, 96, 98 are

flexible enough to be withdrawn, as shown in Figure 5, from pockets 80

after suturing of each commisure 26, 28, 30 as previously described.

Positioning and stabilizing device 90 may be formed from various materials and in various configurations for this purpose. These may include metals,

super elastic alloys, or plastics.

Figures 6 and 6A illustrate another alternative positioning and

stabilizing device 1 00 constructed in accordance with the invention. In this

embodiment, an annular portion 1 02 is removable from a plurality of

commisure stabilizers 1 04, 1 06, 1 08. In this manner, positioning and

stabilizing device 1 00 may be used as described above with respect to

devices 60 and 90, except that annular portion 1 02 may be removed for

easier suturing access or other securement access when securing

commisures 26, 28, 30 (Figure 4) to aortic wall 1 0a. One of many

possibilities for facilitating this function is shown in Figure 6 and Figure 6A

in the form of connectors 1 1 0, 1 1 2, 1 14. Each of these connectors may

receive a stabilizer 1 04, 1 06, 1 08 in a removable fashion with a slight

interference fit. As best shown in Figure 6A, an end portion 1 04a of

stabilizer 1 04 may be received with a slight interference fit against a

resilient tab 1 1 6. The other stabilizers 1 06, 1 08 may have a similar

structure, as exemplified by end 1 08a shown in Figure 6. Many other

fastening structures are possible other than this schematically illustrated

example.

Figure 7 illustrates another alternative positioning and

stabilizing device 1 20 having a generally similar construction and function

to device 90 shown in Figure 5. Device 1 20 may be formed from a single

length of wire, for example, and includes portions 1 22, 1 24, 1 26

analogous to the previously described annular portions. A connector 1 28 may be provided to connect opposite ends of the wire. Stabilizers 1 30,

1 32, 1 34 are formed with three sections each for purposes previously

described in connection with Figure 5. These sections 1 30a-c, 1 32a-c,

1 34a-c serve similar functions to position and stabilize the commisures of a

replacement heart valve, and device 1 20 may be removed from the heart

valve in previously described manners.

Figures 8A and 8B illustrate another alternative positioning and

stabilizing device 1 40 constructed from a shape memory material such as

Nitenol. As shown in Figure 8A, device 1 40 may be collapsed in each a

detached form with respect to a heart valve, as shown, or while connected

to a replacement heart valve for insertion within the patient's aorta as a

unit. Upon the application of heat or electric current once inserted within

the aorta, device 1 40 expands to the position shown in Figure 8B and may

then be used as previously described to position and stabilize the heart

valve commisures during implantation. As shown in Figures 8A and 8B,

one illustrative example of this device also includes an annular portion 1 42

and respective three-legged commisure stabilizers 1 44, 1 46, 1 48.

Figures 9 and 9A illustrate another heart valve replacement

apparatus 1 60 constructed in accordance with the invention. In this

embodiment, a replacement heart valve 1 62 may include a flexible material

1 64, optionally part of the fabric covering 1 66 of valve 1 62, which secures

the three commisures 1 68, 1 70, 1 72 together at their respective distal

ends 1 68a, 1 70a, 1 72a. It will be appreciated that flexible material 1 64

may be stitched to the interior aortic wall in conjunction with commisures 168, 170, 172. Thus, material 164 will prevent distal ends 168a, 170a,

172a from expanding away from one another as occurs during late

sinotubular enlargement of the aorta. Therefore, this prevents valve failure

as a result.

As further shown in Figures 9, 9A and 9B, an alternative

embodiment of a positioning and stabilizing device 180 includes an annular

portion 182 constructed from separate sections 182a, 182b, 182c, and a

plurality of three stabilizers 184, 186, 188. Stabilizer 184, 186, 188 again

are shown as three-legged structures for purposes previously described. In

this embodiment, however, stabilizers 184, 186, 188 are retained within

loops 190, which may be suture loops sewn into fabric 166. It will be

appreciated that other types of retaining structure may be used to at least

temporarily retain stabilizers 184, 186, 188. In this embodiment,

connectable end portions 192, 194, formed respectively as male and

female portions, may be used to make various connections and

disconnections on device 180. For example, lower ends of adjacent

stabilizers 184, 186, 188 may be connected at a junction 196 as shown in

Figure 9. This may provide more consistent support along the edges of

commisures 168, 170, 172. As further shown in Figure 9B, stabilizers

184, 186, 188 may be completely disconnectable from annular portion 182

while also allowing selective disconnection of sections 182a, 182b, 182c.

This may be accomplished through the use of connecting elements 198

having respective female connecting portions 198a for engaging male

connecting portions 192. It will be understood that many alternative connectors and structures may be substituted for those shown while

retaining the basic function and general concepts expressed herein.

Figure 1 0 illustrates a heart valve replacement apparatus 200

comprised a replacement heart valve 202, which may be formed from

biological tissue or synthetic biologically compatible material. Heart valve

202 is again illustrated with three commisures 204, 206, 208, as is typical

for replacement aortic valves. A positioning and stabilizing device 21 0 is

fastened to the outside of valve 202, for example, by suture loops 21 1 .

This embodiment of the invention does not have any connection between

the distal ends 204a, 206a, 208a of commisures 204, 206, 208 or at the

distal end of positioning and stabilizing device 21 0. Also, in this

embodiment positioning and stabilizing device 21 0 is formed in three

sections 21 2, 21 4, 21 6 removably connected together at junctions 21 8,

220, 222. These connections may be similar to those shown in Figure 9B.

Other types of connections may be used as well. Use of this embodiment

of the invention will be similar to the previous embodiments, except that

sections 21 2, 21 4, 21 6 may be removed individually from heart valve 202

following completion of its securement within the aorta. Sections 21 2,

21 4, 21 6 are preferably formed of a highly flexible plastic or metal which is

biocompatible. This embodiment provides certain advantages, such as

allowing one or more of the sections 21 2, 21 4, 21 6 to remain in place

following surgery and providing additional room for a surgeon to access

commisures 204, 206, 208 while suturing or otherwise securing

commisures 204, 206, 208 to the aortic wall. It will be appreciated that other configurations and numbers of legs and sections may be utilized by

those of ordinary skill.

Figure 1 1 illustrates an expansion device 240 useful for

expanding a vessel, such as the aorta, during valve replacement

procedures. In this embodiment, expansion device may be formed as a

collapsible and expandable structure, such as by being formed of shape

memory material as described with respect to Figures 8A and 8B. It will be

appreciated that Figure 1 1 shows the expanded condition only. Expansion

device 240 may have three extensions 242, 244, 246 of a desired length

for disposition between the respective commisures of an aortic replacement

valve. Device 240 need not be attached to heart valve commisures, but

may be used to expand the collapsed aorta to the proper flared shape

thereby assisting the surgeon during a heart valve replacement procedure.

This device overcomes the drawbacks of typical retractors which tend to

distort the shape of the collapsed aorta and mislead the surgeon as to the

correct position and orientation of the heart valve. Device 240 may be

formed in various manners to be collapsible and selectively expandable,

such as through the use of mechanically expandable portions or, preferably,

expandable shape memory portions.

Figures 1 2, 1 3A and 1 3B illustrate an alternative collapsible

and expandable retraction device 250. This device may be formed from a

mesh or screen material and includes edge portions 252, 254 which allow

expanding and contracting of the device. An upper end 256 is formed with

a greater diameter than a lower end 258 in the expanded, operative position shown in Figures 1 2 and 1 3B. This allows a surgeon to have

greater access into and through the device to manipulate and, for example,

suture a replacement heart valve in place below device 250 within the

aorta. In use, and referring back to Figure 1 , a surgeon will insert the

device 250 in the collapsed form shown in Figure 1 3A through opening 1 2

such that lower end 258 is situated within aorta 1 0 and upper end 256 is

exposed. The surgeon will then allow device 250 to expand through its

own resilience or through a shape memory property to the position shown

in Figure 1 3B. Alternatively, other activation structure or means may be

provided for attaining the expanded condition. Once expanded, aorta 10

generally assumes a natural, pressurized shape allowing placement and

implantation of replacement valve 20 in a more efficient and accurate

manner. It will be understood that the expansion devices shown in Figures

1 1 through 1 3B are illustrated in the simplest currently contemplated

forms. It is further contemplated that additional handles or other support

and actuation structure may be added while achieving the same general

advantages of these embodiments.

Figure 1 5 illustrates another embodiment of the invention.

Specifically, a cannulating device 320 is connected to a vessel 322 by

inserting a tube 324 containing a lumen 326 for introducing fluids into

vessel 322. A suture 328 is tied around the outside of vessel 322, as

shown, and has at least one end secured to a friction lock 332, as best

shown in Figure 1 5A. Friction lock 332 may take many different forms,

however, one simple form is the tab, as shown, with a knurled or roughened undersurface 334 for retaining suture 328 in place and keeping

vessel 322 from sliding off tube 324.

Figures 1 6-1 9 illustrate two additional and similar

embodiments of a cannulating device 340, 340' . Like reference numerals

refer to like structure in these embodiments. As shown in Figure 1 6, a

cannulating device 340 is again shown as used on a vessel 342. A cannula

or tube 344 of device 340 is inserted into vessel 342 and includes a lumen

346 for introducing fluids. A clamp 348 is secured to a hub 350 of device

340 and may take many different forms. In the embodiments shown,

clamp 350 generally comprises a pair of jaws 352, 354. In the

embodiment shown in Figures 1 7 and 1 8, a rubber ligature 356 may be

used and moved from the position shown in Figure 1 8 to the position

shown in Figure 1 7 to clamp jaws 352, 354 against vessel 342. Ligature

356 may be retained in respective recesses 358, 360 when jaws 352, 354

are in the closed position. Each jaw 352, 354 includes a respective semi-

cylindrical jaw portion 362, 364 for partially encircling vessel 342 as best

shown in Figure 1 9.

As further shown in Figures 1 6-1 8, devices 340 and 340' may

be easily manipulated between open and closed positions by way of

handles 366, 368, which may form part of jaws 352, 354 and which are

secured to hub 350 by way of pivot connections 370, 372. It will be

appreciated that various other retaining members and clamps may be used

and, as more specifically related to the embodiments shown, other spring-

biased mechanisms may be used to retain jaws 352, 354 in the closed position. For example, one or more torsion springs (not shown) may be

incorporated into the device 340 shown in Figure 1 6 to normally bias jaws

52, 54 into a closed position.

Additional aspects of the invention are apparent from Figures

1 7 and 1 8. Specifically, with ligature 356 engaged as shown in Figure 1 7,

jaws 352, 354 are biased into a normally closed position as shown in solid

lines. However, the user may squeeze handles 366, 368 together, as

shown in phantom lines. This allows repositioning of device 340' or

handles 366, 368 may be squeezed in this manner while initially attaching

device 340' to vessel 342. As further shown in Figure 1 8, ligature 356

may be moved to a rearward position to hold jaws 352, 354 in an open

position. This holds handles 366, 368 against hub 350. This may be used

as an alternative manner of initially inserting tube 344 (Figure 1 6) into

vessel 342. Once inserted, ligature 356 may be moved into recesses 358,

360 or 359, 361 . As further shown in Figure 1 8, multiple sets of recesses

358, 360 and 359, 361 may provide different degrees of clamping force.

In this illustrative example, recesses 359, 361 will provide greater clamping

force as they are a greater distance apart.

Figures 22 and 23 show another embodiment of the invention.

The electrode comprises a clip 430 which can be pinched onto the heart

432 (Figure 23) for quick attachment with a clip applier. There will be no

bleeding since there is no hole and tissue is merely pinched. The electrode

430 is attached to a wire 434 in a releasable manner. This may be

accomplished with engageable and disengageable loops 436, 438 as shown. When the wire 434 is removed, the electrode stays on the heart

and so there is no ripping of tissue.

Figures 24 and 25 show an alternate attachment of the wire

434 and an alternative electrode 440. This provides even less friction on

removal. It is also easy to see that if the wire 434 comes free accidently

during surgery, it would be very easy to reattach. This is because of the

frictional engagement members 442, 444. Figures 24 and 25 also show an

electrode variation as mentioned above. In this embodiment, there is a

spike 446 that impales the heart which is then squeezed on with a clip

applier as with the first embodiment. This assures better contact with the

heart muscle.

Figure 26 shows another way to attach an electrode to the

heart with a scorpion-type pincer 450 that is pinched with a clip applier.

The sharp ends are squeezed together by the clip applier. Another

alternative releasable electrode/wire link is shown. This again includes

engageable and disengageable members 452, 454.

While the present invention has been illustrated by a

description of a preferred embodiment and while this embodiment has been

described in some detail, it is not the intention of the Applicants to restrict

or in any way limit the scope of the appended claims to such detail.

Additional advantages and modifications will readily appear to those skilled

in the art. The various features and concepts of the invention may be used

alone or in numerous combinations depending on the needs and preferences

of the user. This has been a description of the present invention, along with the preferred methods of practicing the present invention as currently

known. However, the invention itself should only be defined by the

appended claims, wherein we claim:

Claims

1 . Apparatus for replacing a heart valve within a vessel, the

apparatus comprising:

a replacement heart valve having an annular base and a

plurality of commisures extending from the annular base at spaced apart

positions, each commisure having a proximal end connected with the

annular base and an opposite distal end, and

a plurality of commisure stabilizers connected to the

replacement heart valve in a removable manner, wherein the commisure

stabilizers position and stabilize the commisures of the replacement heart

valve as the replacement heart valve is secured within a vessel but are

removable from the replacement heart valve following securement thereof

within the vessel.

2. The apparatus of claim 1 , wherein the commisure stabilizers

are connected together at the spaced apart distal positions by a generally

annular member and each commisure stabilizer further comprises at least

one elongate member.

3. The apparatus of claim 2, wherein the three elongate members

each curve outwardly in a lengthwise direction to urge the commisures of

the replacement heart valve against an interior wall of the vessel.

4. The apparatus of claim 2, wherein the replacement heart valve

includes respective receiving elements to removably receive the respective

commisure stabilizers.

5. The apparatus of claim 4, wherein the receiving elements

further comprise pockets.

6. The apparatus of claim 4, wherein the receiving elements

further comprise loops affixed to said commisures.

7. The apparatus of claim 2, wherein the commisure stabilizers

are removably affixed to the generally annular member.

8. The apparatus of claim 2, wherein each commisure stabilizer

further comprises at least two spaced apart elongate members.

9. The apparatus of claim 1 , wherein each commisure stabilizer

further comprises an elongate central member and a pair of elongate side

members angled away from the elongate central member and extending

along opposite edge portions of the respective commisure.

10. The apparatus of claim 1 , wherein the positioning and

stabilizing device is formed in a collapsible manner allowing insertion into

the vessel in a collapsed state and subsequent expansion for positioning

and stabilizing the valve commisures during securement of the valve within

the vessel.

1 1 . The apparatus of claim 1 1 , wherein the positioning and

stabilizing device is at least partially formed of a shape memory material

allowing the positioning device to be selectively collapsed and expanded.

1 2. The apparatus of claim 1 further comprising a flexible material

connecting the distal ends of the three commisures.

1 3. The apparatus of claim 1 , wherein said replacement heart

valve is formed from animal or human tissue.

1 4. The apparatus of claim 1 , wherein said replacement heart

valve is formed from a synthetic biologically compatible material.

1 5. The apparatus of claim 1 , wherein said commisure stabilizers

are connected to the commisures of said replacement heart valve in a

removable manner.

1 6. A replacement heart valve for implantation within a vessel, the

replacement heart valve comprising:

an annular base,

a plurality of commisures extending from the annular base at

spaced apart positions, said commisures having proximal ends connected

with said annular base and opposite distal ends, and

a flexible fabric material connecting the distal ends of said

commisures and adapted to be secured to said vessel during implantation.

1 7. An expandable and collapsible vessel retraction device

comprising:

a body movable between expanded and collapsed conditions

such that, in the collapsed condition the body may be inserted into an open

vessel and actuated into the expanded condition whereby said vessel

expands into a shape substantially corresponding to the natural pressurized

shape of the vessel.

1 8. The vessel retraction device of claim 1 7, wherein the body is

generally tubular.

1 9. The vessel retraction device of claim 1 7, wherein the body is

at least partially formed of a shape memory material.

20. A method of implanting a replacement heart valve including an

annular base and a plurality of commisures extending from spaced apart

positions of the annular base, the method comprising:

inserting said replacement heart valve into a patient,

connecting at least one commisure stabilizer to each of said

commisures of said replacement heart valve either before or after inserting

said replacement heart valve,

securing said replacement heart valve within the patient using

said commisure stabilizers to orient the commisures of the replacement

heart valve, and

removing said commisure stabilizers from the patient leaving

the secured replacement heart valve in place.

21 . A method of implanting a replacement heart valve including an

annular base and a plurality of commisures extending from spaced apart

positions of the annular base, the method comprising:

connecting three commisure stabilizers of a positioning and

stabilizing device to the respective three commisures of said replacement

heart valve,

inserting said replacement heart valve into a patient,

securing said replacement heart valve within the patient using

said commisure stabilizers to orient the three commisures of said

replacement heart valve, and removing said positioning and stabilizing device from the

patient leaving the secured replacement heart valve in place.

22. A cannulating device comprising:

a hub portion;

a cannula extending from said hub portion and adapted to be

inserted into a blood vessel; and

a retaining member extending from the hub portion and

adapted to retain a suture tied around the blood vessel to prevent the blood

vessel from slipping off the cannula.

23. The cannulating device of claim 22, wherein the retaining

member is a frictional engagement member.

24 The cannulating device of claim 23, wherein the frictional

engagement member includes a roughened surface for engaging the suture.

25. The cannulating device of claim 22, wherein a space is formed

between the hub and the retaining member for receiving and retaining the

suture.

26. A cannulating device comprising:

a hub portion;

a cannula extending from said hub portion and adapted to be

inserted into a blood vessel; and

a clamp coupled with the hub portion and adapted to retain the

blood vessel in a sealed condition on the cannula.

27. The cannulating device of claim 26 further including a biasing

mechanism operative to bias the clamp into at least one of an open position

and a closed position with respect to the vessel.

28. The cannulating device of claim 27, wherein the biasing

mechanism is an elastic ligature.

29. The cannulating device of claim 28, wherein the elastic

ligature is adjustable to provide different degrees of clamping force.

30. The cannulating device of claim 26, wherein the clamp

includes jaws with semi-cylindrical portions for receiving the vessel.

31 . The cannulating device of claim 26, wherein the clamp

includes soft jaw portions for engaging the vessel.

32. A temporary pacemaker lead for connection with heart tissue

of a patient, the temporary pacemaker lead comprising:

a wire having an electrically conductive portion;

a first connector portion on the wire;

an electrode having a second connector portion releasably

engaged with said first connector portion so as to establish electrical

conduction between the electrode and the electrically conductive portion of

the wire, whereby said electrode may be affixed to the heart tissue and

said wire may be releasably secured to the electrode by way of the first and

second connector portions.

33. The temporary pacemaker lead of claim 32, wherein said first

and second connector portions comprise engageable and disengageable

loops.

34. The temporary pacemaker lead of claim 32, wherein the

connector portions each comprise frictionally engaging connector portions.

35. The temporary pacemaker lead of claim 34, wherein the

second connector portion further comprises a pair of frictional engagement

elements.

36. The temporary pacemaker lead of claim 32, wherein the

electrode further includes a spike portion for insertion into the heart tissue.

37. The temporary pacemaker lead of claim 32, wherein the

electrode further comprises a pair of spike portions adapted to be moved

together into the heart tissue.

38. A temporary pacemaker lead for connection with heart tissue

of a patient, the temporary pacemaker lead comprising:

a wire having an electrically conductive portion;

a first connector portion on the wire;

an electrode clip having a second connector portion releasably

engaged with said first connector portion so as to establish electrical

conduction between the electrode clip and the electrically conductive

portion of the wire, said electrode clip having at least one movable portion

allowing fixation of the clip to the heart tissue and wherein said wire may

be releasably secured to the electrode clip by way of the first and second

connector portions.