Docking arrangement

A stent graft introducer has a nose cone dilator (8) and a distally opening capsule (18) on the nose cone dilator, a balloon guide (2, 30) extending into the capsule and affixed therein. Upon completion of deployment of a stent graft, a balloon catheter (96) including an inflatable balloon (98) thereon can be advanced over the balloon guide at least partially into the nose cone whereby the balloon can be inflated therein to provide a smooth transition from the nose cone to a delivery sheath (10) for retraction of the nose cone dilator through the deployed stent graft. The balloon guide can be a separate wire (30).

TECHNICAL FIELD

This invention relates to a medical device and more particularly to a medical device used for deployment of an intraluminal graft or stent graft.

BACKGROUND OF THE INVENTION

In the deployment of a graft or stent graft into the human or animal body via intraluminal techniques a deployment device is used to introduce the graft and, after the graft has been deployed and expanded within the lumen, the introducer needs to be retracted.

One form of introducer uses a distally facing capsule to encompass an exposed stent of a stent graft during introduction and after the stent graft has been released and the capsule has been removed from the exposed stent, the capsule along with the introducer must withdrawn. The capsule, however, has a distally facing opening and edge and this can engage with stents of the just introduced stent graft and cause problems with dislodging the stent graft from its position on the wall of the lumen. Similarly, an introducer often has a sheath which is used to constrain a stent or stent graft during delivery and is withdrawn from the stent or stent graft to release the stent or stent graft. This sheath has a proximally facing opening and edge and if the sheath is advanced to meet the nose cone then that edge may engage with stents of the just introduced stent graft and cause problems with dislodging the stent graft from its position on the wall of the lumen.

It is the object of this invention to provide an arrangement by which the nose cone can be retracted to the sheath so that introducer as a whole can be retracted without causing such problems.

Throughout this specification the term distal with respect to a portion of the aorta, a deployment device or a prosthesis means the end of the aorta, deployment device or prosthesis further away in the direction of blood flow away from the heart and the term proximal means the portion of the aorta, deployment device or end of the prosthesis nearer to the heart. When applied to other vessels similar terms such as caudal and cranial should be understood.

SUMMARY OF THE INVENTION

In one form therefore the invention is said to reside in a stent graft introducer comprising a nose cone dilator and a distally opening capsule on the nose cone dilator and a balloon guide extending into the capsule and affixed therein whereby upon completion of deployment of a stent graft from the introducer, a balloon catheter including an inflatable balloon thereon can be advanced over the balloon guide at least partially into the nose cone and the balloon be inflated therein to provide a smooth transition from the nose cone to a delivery catheter for retraction of the nose cone dilator through the deployed stent graft.

Preferably the balloon is a non-compliant balloon whereby upon inflation it inflates to a selected size and shape only.

Preferably the introducer further comprises a guide wire catheter extending to and through the nose cone dilator and the balloon guide is the guide wire catheter. Alternatively the balloon guide is a separate guide wire.

In an alternate form the invention resides in a stent graft introducer comprising guide wire catheter, a nose cone dilator on the proximal end of the guide wire catheter, a distally opening capsule on the nose cone dilator, a sheath coaxially around the guide wire catheter and spaced apart therefrom to define an annular sheath lumen therein and a balloon guide extending through the sheath lumen and into the capsule and affixed therein, whereby upon completion of deployment of a stent graft, a balloon catheter including an inflatable balloon thereon can be advanced over the balloon guide at least partially into the nose cone and the balloon be inflated therein and the nose cone dilator and the inflated balloon retracted together such that the inflated balloon docks into the sheath whereby provide a smooth transition from the nose cone to the sheath for retraction of the stent graft introducer through the deployed stent graft.

Preferably the balloon is a non-compliant balloon whereby upon inflation it inflates to a selected size and shape only and is shaped to be substantially the same diameter as the sheath when in an inflated state.

In one embodiment the guide wire catheter is the balloon guide or alternatively the balloon guide is a separate guide wire extending through the sheath lumen.

In an alternate form the invention resides in a stent graft introducer comprising guide wire catheter, a nose cone dilator on the proximal end of the guide wire catheter, a distally opening capsule on the nose cone dilator, a sheath coaxially around the guide wire catheter and spaced apart therefrom to define an annular sheath lumen therein, a balloon guide extending through the sheath lumen into the capsule and affixed therein, a stent graft retained in the sheath lumen distally of the capsule, the stent graft comprising a proximally extending exposed stent and the proximally extending exposed stent being received and retained in the capsule of the nose cone dilator, whereby upon completion of deployment of the stent graft by retraction of the sheath and advancement of the nose cone dilator to remove the capsule from the proximally extending exposed stent, a balloon catheter including an inflatable balloon thereon can be advanced over the balloon guide at least partially into the nose cone whereby the balloon can be inflated therein and the nose cone dilator and the inflated balloon retracted such that the inflated balloon docks into the sheath whereby provide a smooth transition from the nose cone to the sheath for retraction of the stent graft introducer through the deployed stent graft.

Preferably the balloon is a non-compliant balloon whereby upon inflation it inflates to a selected size and shape only and is shaped to be substantially the same diameter as the sheath when in an inflated state.

In one embodiment the guide wire catheter extending is the balloon catheter and during the deployment of the stent graft the balloon catheter including the inflatable balloon is on the guide wire catheter distally of the retained stent graft.

Alternatively the balloon guide is a separate guide wire extending through the sheath lumen and the balloon catheter including the inflatable balloon is introduced onto the balloon guide after deployment of the stent graft. Alternatively the balloon catheter including the inflatable balloon may be carried on the separate guide wire distally of the retained stent graft during introduction.

In an alternate form the invention resides in a stent graft introducer comprising guide wire catheter, a nose cone dilator on the proximal end of the guide wire catheter, a distally opening capsule on the nose cone dilator, a sheath coaxially around the guide wire catheter and spaced apart therefrom to define an annular sheath lumen therein, a stent graft retained in the sheath lumen distally of the capsule, the stent graft comprising a proximally extending exposed stent and the proximally extending exposed stent being received and retained in the capsule of the nose cone dilator, a balloon catheter mounted coaxially onto the guide wire catheter and able to be moved therealong, during deployment the balloon catheter being positioned distally of the stent graft, whereby upon completion of deployment of the stent graft by retraction of the sheath and advancement of the nose cone dilator to remove the capsule from the proximally extending exposed stent, a balloon catheter including an inflatable balloon thereon can be advanced along the guide wire catheter at least partially into the nose cone whereby the balloon can be inflated therein and the nose cone dilator and the inflated balloon retracted such that the inflated balloon docks into the sheath whereby provide a smooth transition from the nose cone to the sheath for retraction of the stent graft introducer through the deployed stent graft.

It will be seen that by this invention there is provided an arrangement by which a balloon can be introduced at least partially into the capsule of an introducer after deployment of the stent graft and the balloon inflated until it is approximately the same diameter as the capsule. During retraction the balloon will act as a fairing to prevent the capsule engaging against the previously introduced stent graft until such time as the capsule is fully retracted or retracted sufficiently into an introducer sheath that the whole device can be withdrawn successfully.

As discussed above the balloon catheter and inflator balloon can be carried on the stent graft introducer distally of a stent graft during the introduction process and advanced when it is required to be used to assist with docking of the capsule.

Alternatively the balloon catheter can be introduced through a hemostatic seal on the introducer over the separate guide wire and advanced into the nose cone and inflated as discussed above.

This then generally describes the invention but to assist with understanding reference will now be made to the accompanying drawings which show in a stylised form preferred embodiments of the invention.

DETAILED DESCRIPTION

FIGS. 1A to 1Eshow in a stylised manner the operation of a docking balloon arrangement according to one embodiment of the invention.

In this embodiment, as shown inFIG. 1A, the stent graft introducer has a nose cone dilator8with a distally facing capsule18(shown in section inFIG. 1A) mounted onto a guide wire catheter24. The guide wire catheter passes through the outer sheath6. An auxiliary guide wire30which extends substantially parallel to the guide wire catheter24and extends into the capsule18and is fixed inside the capsule and terminates at point27. The auxiliary guide wire30extends through the sheath6and haemostatic seal124(seeFIGS. 3 and 4) of the introducer.

After the stent graft has been deployed, the introducer is as shown inFIG. 1A. At this stage, if the nose cone dilator8with capsule18is retracted to dock with the sheath6to enable their retraction together then the distal edge29of the capsule18could catch against portions of stents within an introduced stent or stent graft and cause the stent or stent graft to be dislodged. Similarly, if the sheath6is advanced so that the sheath docks with the capsule then the leading edge6aof the sheath6could catch against portions of stents within an introduced stent graft and cause the stent graft to be dislodged. It is necessary to have an arrangement for providing a fairing to prevent engagement with the stents of the stent graft.

As shown inFIG. 1Ba balloon catheter96has been introducer over the auxiliary guide wire30through the hemostatic seal (not shown). The balloon catheter96includes a inflatable balloon98.

The balloon catheter96and balloon98are advanced along the auxiliary guide wire25until its proximal end98ais received within the capsule18as shown inFIG. 1C. The balloon98is then inflated as shown inFIG. 1Duntil it is substantially the same diameter as the capsule18.

The nose cone8, capsule18and balloon98can then be retracted until the distal end98bof the balloon98is engaged within the sheath6as shown inFIG. 1Eand then the entire introducer device can be retracted without potential problems of engagement against stents of an already deployed stent graft. Alternatively the nose cone dilator8, capsule18, balloon98and guide wire catheter24can all be withdrawn leaving the sheath6in place.

FIGS. 2A to 2Dshow an alternative embodiment of docking arrangement according to the present invention.

FIG. 2Ashows a schematic view of part of a stent graft introducer. The stent graft introducer includes a guide wire catheter2which extends from outside the body of a patient in use to a proximal end4upon which is mounted a nose cone dilator6and a distally facing capsule8. A sheath10surrounds a the guide wire catheter. At the stage shown inFIG. 2Aa stent graft (not shown) has been deployed and the introducer is ready to be withdrawn.

At this stage, if the nose cone dilator6with capsule8is retracted to dock with the sheath10to enable their retraction together then the distal edge12of the capsule8could catch against portions of stents within an introduced stent or stent graft and cause the stent or stent graft to be dislodged. Similarly, if the sheath10is advanced so that the sheath docks with the capsule then the leading edge22of the sheath10could catch against portions of stents within an introduced stent graft and cause the stent graft to be dislodged. It is necessary to have an arrangement for providing a fairing to prevent engagement with the stents of the stent graft.

According to this embodiment of the invention, therefore, a balloon catheter14including an elongate catheter16and an inflatable balloon18is advanced over the guide wire catheter until, as shown inFIG. 2B, the proximal end of the inflatable balloon18is received into the capsule8. The balloon18is formed from a non-compliant material such that when inflated it forms a selected size and shape and will not normally expand beyond that size. The desired size and shape is approximately sausage shape with a diameter approximately the same as the capsule on the nose cone dilator.

FIG. 2Cshows the balloon18inflated until it is substantially the same size as the outer diameter of the capsule8. At this stage the balloon18presents a rounded distal end20which will not engage deleteriously with the stents of a stent graft.

The balloon catheter, balloon nose cone dilator and capsule can then be withdrawn until the distal end20of the balloon18is received in the proximal end22of the sheath10as shown inFIG. 2D.

At this stage if it is desired to leave the sheath10in place for subsequent deployment of stent grafts through the sheath the balloon18, capsule8and nose cone6can be withdrawn through the sheath or alternatively the sheath as well can be withdrawn to completely retract the introducer and its components from the vessel of the human or animal body.

FIG. 3shows an alternative embodiment of a multi port stent graft introducer incorporating a docking balloon arrangement according to the present invention.FIG. 4shows in more detail the manifold and handle portion102of the delivery device shown inFIG. 3.

The introducer device100shown inFIG. 3comprises a handle and manifold assembly102and introduction portion104intended to be deployed into the patient. The introduction section104includes an outer sheath106extending from an outer sheath manipulator108to a nose cone dilator110. A stent graft is retained within the outer sheath106in the region107just distal of the nose cone dilator110.

The outer sheath manipulator108is positioned over an inner sheath112which extends back and is fastened to the manifold114. The inner sheath112extends proximal at least to a forward most position of the outer sheath manipulator108and preferably within the outer sheath to just distal of the stent graft retained within the outer sheath106. The manifold114has a proximal end114bto which is connected the outer sheath112and four access ports at its distal end114a. Access port116is for a first access sheath118. Access port120is for a second access sheath122. A third access port124is for a docking balloon catheter126.

A fourth port128provides access to the handle130which includes trigger wire release mechanisms as discussed below.

The access sheath118extends to a haemostatic seal132through which extends the dilator134. On the dilator134is a dilator haemostatic seal136through which extends an indwelling guide wire138.

The access sheath122extends to a haemostatic seal140through which extends the dilator142. On the dilator142is a dilator haemostatic seal144through which extends an indwelling guide wire146.

The use of access sheaths118and122is discussed in co-pending U.S. patent application entitled “Multiport Delivery Device” (Ser. No. 11/807,878 filed May 30, 2007) the teaching of which is incorporated herein in its entirety.

The auxiliary balloon guide wire154extends through the balloon catheter haemostatic seal152and the inner and outer sheaths112and106proximally to the nose cone dilator110and is fastened to the nose cone dilator110within the capsule117. The balloon catheter126extends through balloon catheter haemostatic seal124and the inner and outer sheaths112and106proximally to just distal of the region107where the stent graft is carried. The balloon catheter has a non-compliant balloon127at its proximal end. The balloon catheter126includes an inflation lumen (not-shown) through which inflation medium can be supplied to the balloon127via inflation port150.

The handle assembly130includes trigger wire release mechanisms as follows. Trigger wire release162is for the diameter reducing ties on a stent graft carried on the delivery device, trigger wire release160is for the guide wire retention release wire (not shown). Trigger wire release164is for the retention trigger wire for a stent graft exposed stent in a distally facing capsule on the nose cone dilator110. Trigger wire release mechanism166is for the distal end of the stent graft.

A pin vice170is at the rear of the handle130and the guide wire catheter172for the introducer device extends through the pin vice170and is locked for movement with respect to the handle130by the pin vice. The guide wire catheter172terminates in a syringe point174to enable flushing liquid and radiopaque medium to be deployed through the delivery device.

FIG. 5shows the delivery device ofFIGS. 3 and 4after delivery of a stent graft and before retraction of the nose cone dilator. The vasculature into which the stent graft has been delivered is not shown for reasons of clarity. At this stage each of the access sheaths118and122(seeFIG. 3) have been withdrawn and the trigger wire release mechanisms162,160,164and166(seeFIG. 3) have also been withdrawn. Also at this stage the stent graft109would be engaged against the wall of the vessel into which it has been deployed but the exposed stent111and the internal stents113could be engaged by the either the distal edge115of the capsule117if that was retracted to the sheath or the proximal edge106aof the outer sheath106if that was advanced to the capsule.

FIG. 5shows that the balloon catheter126has been advanced over the guide wire154until the proximal end127aof the balloon127has been received in the capsule117and the balloon has been inflated until it is approximately the same diameter as the nose cone dilator117and the outer sheath106.

The nose cone dilator117, the balloon127and balloon catheter126can then all be withdrawn together until the distal end127bof the balloon127is received in the proximal end106aof the outer sheath106. Then either the entire delivery device100can be withdrawn or the nose cone dilator117, the balloon127and balloon catheter126can then all be withdrawn together until they are received in the inner sheath112and then these along with the handle assembly102can be withdrawn leaving the outer sheath106in place for subsequent endovascular procedures therethrough.

Throughout this specification various embodiments of the invention have been discussed but the invention is not limited to any one of them but may reside in two or more combined together in part or in whole. The examples are given for illustration only and not for limitation.