US20200337564A1

Movatterモバイル変換

Info

Publication number: US20200337564A1
Application number: US16/923,885
Authority: US
Inventors: Jon H. Hoem; Oliver A. Kohr
Original assignee: Miracor Medical SA Belgium
Current assignee: Miracor Medical SA Belgium
Priority date: 2010-05-25
Filing date: 2020-07-08
Publication date: 2020-10-29
Also published as: US10743780B2; US20110295301A1

Abstract

Some embodiments of a balloon catheter device for introduction into a body vessel, in particular the coronary sinus, can include a catheter shaft which carries an inflatable balloon on its distal portion and in which a plurality of different lumens are formed. In particular embodiments, a system for treating heart tissue can include a coronary sinus occlusion catheter configured for improved deliverability to the coronary sinus and for thereafter performing intermittent occlusion of the coronary sinus.

Description

TECHNICAL FIELD

This document relates to a balloon catheter for introduction into a body vessel, such as the coronary sinus, and the occlusion of the same, including a catheter shaft which carries an inflatable balloon on its distal end portion and in which a plurality of lumens are formed.

BACKGROUND

Balloon catheters including inflatable balloons can, for instance, be taken from EP 402964 B1. The known balloon catheter serves for coronary sinus occlusion, wherein diagnostically valuable signals can be obtained by a plurality of sensors and the inflation of the balloon can be controlled, in particular, with a view to achieving retroperfusion. Such a balloon catheter is also known as a multi-lumen catheter, whose distal end projects, for instance, into the coronary sinus of the heart, while the proximal end of the catheter is connected with a pump for inflating the balloon. Wires for electrically contacting sensors can be conducted through further lumens arranged coaxially or in parallel with the lumen that serves to inflate the expandable balloon. Via such further lumens, cardioplegic or thrombolytic, or other pharmacologically active substances suitable for retroperfusion in ischemic tissue, can also be introduced.

In order to supply ischemic tissue with blood by retrograde perfusion, it has already been proposed to use an inflatable balloon fixed to the end of a catheter to intermittently occlude the coronary sinus. The blood pressure in the coronary sinus rises during the occlusion at every heart beat so as to cause blood reaching the coronary sinus through the healthy tissue of the heart muscle to be flushed back into the ischemic tissue. Another effect of intermittent occlusion is the influence on the pressure regulation due to the feedback mechanism by neuro-stimulative effects. For such intermittent coronary sinus occlusion, the balloon end of the catheter is inserted either percutaneously or surgically. The other end of the catheter is supplied by a pump with a gas or fluid which causes the cyclic inflation and deflation of the balloon. A device for the retroperfusion of coronary veins is, for instance, known from WO 2005/120602 A1, by which a pressure-controlled, intermittent coronary sinus occlusion can be performed. In that device and the corresponding method for determining the optimum times for triggering and releasing the occlusion, pressure parameters like the speeds of the pressure increase and pressure drop were determined and subjected to relatively complex processing.

For the percutaneous insertion of a catheter, it is proceeded in a manner that the catheter is guided via the inferior or the superior cava vein into the right atrium of the heart, into which the coronary sinus runs. Due to the position of the mouth of the superior cava vein or inferior cava vein, respectively, relative to the mouth of the coronary sinus, the introduction of the catheter into the coronary sinus requires considerable skill from the cardiologist in order to direct the tip of the catheter, or a guide wire or a guide sleeve, into the coronary sinus in such a manner as to enable the subsequent introduction of the catheter along with the occlusion device. In fact, it frequently happened that several attempts of introduction into the coronary sinus had to be made, which considerably extended the duration of treatment and, hence, the strain on the patient.

Another problem involved in balloon catheters used for the intermittent occlusion of the coronary sinus resides in that blood backed up during the occlusion would exert pressure on the balloon, and hence on the catheter, thus eventually causing the catheter to slip back or kink within the vessel.

SUMMARY

Some systems and methods described herein include an occlusion catheter device that is sufficiently rigid in order to reduce the likelihood the occlusion catheter device will slip back from the occluded position because of the counter-pressure in the occluded vessel. At the same time, the occlusion catheter device may provide sufficient flexibility in order to enable the occlusion catheter device to be safely pushed forward through blood vessel regions having small radii of curvature so as to be able to position an inflatable balloon on the catheter device at the desired site of application (e.g., the coronary sinus in some embodiments).

In particular embodiments, a balloon catheter which is suitable for the intermittent occlusion of a body vessel (e.g., the coronary sinus) can be equipped with the lumens required performing the intermittent occlusion of the body vessel. The balloon catheter can be configured to exhibit both sufficient flexural strength to enhance the pushability of the catheter while also reducing the likelihood that the balloon will not slip back on account of the pressure caused by the backed-up fluid in the occluded vessel, and sufficient flexibility to facilitate its introduction.

In some embodiments, the balloon catheter can include a central lumen having a distal opening in communication with the respective body vessel distally of the balloon. Furthermore, a lumen serving to inflate and deflate the balloon and communicating with the latter is provided. Also, the balloon catheter may include a stiffening element surrounding at least a portion of the catheter shaft, or arranged within at least a portion of the catheter shaft. A distal end portion of the stiffening member, which may be positioned adjacent to the proximal end of the balloon, can have a flexural strength that is reduced relative to the remaining portion of the stiffening element.

The central lumen of the balloon catheter, which includes the distal opening into the respective body vessel distally of the balloon, enables measurement of the pressure prevailing in the body vessel occluded by the balloon (e.g., the coronary sinus pressure in the coronary sinus). In some circumstances, the central lumen also enables the taking of blood from the occluded vessel. Moreover, the central lumen can be used to introduce the balloon catheter into the vessel, and advance it within the vessel to the respectively targeted site, by advancing the central lumen over a guide wire.

In some embodiments, the flexural strength of the balloon catheter is obtained by the stiffening element that surrounds the catheter shaft, or is arranged within the catheter shaft. The stiffening element also facilitates the advancement of the balloon catheter. In order reduce the likelihood of injuring the vessel during the advancement of the catheter, and to permit advancement in curved regions having small radii of curvature, the distal end portion of the stiffening element can be positioned adjacent to the proximal end of the balloon and may provide a flexural strength that is reduced relative to the remaining portion of the stiffening element. Thus, a region of higher flexibility is deliberately formed at the distal end portion of the stiffening element so as to enable the adaptation to a curved course of the body vessel during the advancement of the catheter, while preferably maintaining the balloon-carrying, distal portion of the catheter in a generally parallel relationship with the longitudinal extension of the respective vessel in order to avoid injury to the vessel wall.

In particular embodiments, the stiffening element is preferably formed by a hypotube surrounding the catheter shaft. The stiffening element in this case preferably extends substantially over the entire portion of the catheter shaft between the balloon and the proximal end portion. In a preferred manner, a slight distance is provided between the distal end of the stiffening element and the proximal end of the inflatable region of the balloon. In the embodiment described herein, the distance is dimensioned such that, on the one hand, the catheter shaft will not buckle between the distal end of the stiffening tube and the balloon, which would be the case with too large a distance, and, on the other hand, the flexibility and suppleness will not be limited too much in this region, which would be the case with too short a distance, or no distance at all. In some preferred embodiments, the distance is about 4-6 mm and, in particular, about 5 mm.

In one aspect, the hypotube may be formed by a separate stainless-steel tube or also by at least one outer layer co-extruded with the catheter shaft and made of a synthetic material differing from that of the catheter shaft. Alternatively, the hypotube may be formed by a nylon tissue or comprise such a tissue. In some embodiments, the portion of the stiffening element having a reduced flexural strength extends over a length of about 30-120 mm, preferably about 40-90 mm, from the distal end of the stiffening element.

According to a preferred configuration, the hypotube can include at least one notch influencing the flexural strength. In some embodiments, the notch preferably extends in a helical line-shaped manner, with the helical line or helix having a smaller pitch in the portion of reduced flexural strength of the hypotube than in the remaining portion. As described herein, further optimization is feasible in that the pitch of the helix continuously increases in the portion of reduced flexural strength of the hypotube, departing from the distal end of the hypotube. Due to the continuously variable flexural strength of the hypotube in the mentioned end portion, buckling sites will be avoided.

In alternative embodiments, instead of a helical line-shaped notch, a plurality of notches offset in the axial direction may also be provided on the stiffening element. Each of the notches can extend over a partial circumference of the hypotube, with the flexural strength depending on the axial distance between the individual notches.

For the intermittent occlusion of a body vessel and, in particular, the coronary sinus, a plurality of lumens are usually required such that a particularly space-saving arrangement of the individual lumens is useful in order to maintain the outer diameter of the catheter shaft as small as possible. Accordingly, the lumens of the catheter may have cross-sectional geometries differing from one another. In some embodiments, the inflation lumen that serves to inflate and/or deflate the balloon may have a ring segment-shaped in cross section and arranged radially outside the central lumen.

In some embodiments, a separate lumen in the balloon catheter can be employed to monitor the fluid pressure prevailing in the balloon. In particular embodiments, the balloon pressure-monitoring lumen may have a ring segment-shaped in cross section and arranged radially outside the central lumen, whose arc-determining angle is preferably smaller as compared to the ring segment-shaped inflation lumen serving to inflate and deflate the balloon. Due to the fact that the ring segment-shaped cross section of the inflation lumen extends over a larger central angle than the ring segment-shaped cross section of the balloon pressure-monitoring lumen, a larger cross section is provided for the inflation lumen and, at the same time, separate pressure measurements will be enabled, thus providing a configuration that utilizes the catheter space while maintaining the outer diameter of the catheter shaft accordingly small.

In particular embodiments, the ability for pressure measurement via a separate lumen (e.g., the balloon pressure-monitoring lumen that is separate from the inflation lumen) can provide the advantage that possible buckling under flexural load can be detected. Buckling can be reliably detected due to the different pressures measured in the inflation lumen serving to inflate and deflate the balloon and in the balloon pressure-monitoring lumen. In such circumstances, it is thus feasible to take the respective safety measurements, e.g. actuate a safety valve, in due time.

According to a further preferred configuration, it is provided that a circular or oval lumen is provided between the neighboring ends of the ring segment-shaped lumens. Such a relatively small lumen enables the wiring of electrical sensors arranged in the tip of the catheter or in the region of the balloon, or the arrangement of fiber-optic lines.

In order to avoid possible malfunctions during the inflation and deflation of the balloon, it is provided according to a preferred further development that the inflation lumen, and optionally the balloon pressure-monitoring lumen, are each connected with the interior of the balloon via at least two radial openings arranged to be offset in the axial direction of the catheter. The use of at least two radial openings into the interior of the balloon can reduce the risk of the balloon prematurely covering all openings, particularly during collapsing, i.e. prior to the complete evacuation of the balloon, so that further evacuation would be rendered difficult or impossible.

In some embodiments, the balloon catheter may include a stiffening means, such as a stiffening wire, in the region of the balloon. The stiffening wire may extend over the length of the balloon, and may extend from a region interior to the previously describe hypotube to a distal region interior to a distal collar of the balloon. Such a stiffening means can reduce the likelihood of the catheter shaft buckling or otherwise deforming in the region in which it is surrounded by the balloon, on account of the balloon pressure exerting axial upsetting forces on the catheter shaft. The stiffening means can, for instance, be received in the circular or oval lumen mentioned above. In an alternative embodiment, the stiffening wire may be arranged in a helical wrap around an outer circumference of the catheter shaft in the interior region of the balloon.

In particular embodiments, the distal end of the catheter can be connected with a catheter tip element which comprises an axial lumen provided consecutively to the central lumen of the catheter and having a distal opening, the wall of said axial lumen including at least two, preferably three, radial openings uniformly distributed over its periphery. Such a separate catheter tip component offers various advantages in terms of application. Thus, the edge of the distal opening of the catheter tip element may, for instance, be rounded off so as to prevent damage to the vessel walls. Furthermore, the catheter tip element may conically taper toward the distal opening, and the catheter tip element may, in particular, be designed to be flexible in order to ensure an enhanced guidance of the tip, and hence the overall catheter, within the body vessel. In this respect, the catheter tip element should have a minimum length in order to provide an appropriate bending zone. In a preferred manner, the distance between the distal tip of the catheter tip element and the distal end of the balloon is at least about 30 mm and, preferably, about 35 mm to about 45 mm.

By the axial lumen of the catheter tip element communicating with the body vessel not only via the distal opening of the catheter tip element, but also via at least two, preferably three, radial openings uniformly distributed over its periphery in the wall of the catheter tip element, a more precise measurement of the fluid pressure prevailing in the body vessel has become feasible. In particular, the likelihood of faulty measurements can be reduced because the radial openings can properly measure the fluid pressure in the body vessel eve if the distal opening or one radial opening were in abutment with the vessel wall, or if one opening was not powered with the full pressure prevailing in the vessel for any other reason.

The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view of a portion of a system for treating heart tissue, in accordance with some embodiments.

FIG. 2 is a perspective view of another portion of the system ofFIG. 1.

FIG. 3 is a schematic illustration of a catheter device of the system ofFIG. 1.

FIG. 4 is a detailed view of the balloon of the catheter device ofFIG. 3.

FIG. 5 shows a cross sectional view of the catheter device ofFIG. 3.

FIG. 6 shows a cross sectional view of a portion of the catheter device ofFIG. 4.

FIG. 7 is a cross-sectional view of a catheter tip element of the catheter device ofFIG. 3.

FIG. 8 is a perspective view of the catheter tip element ofFIG. 7.

FIG. 9 is a detailed view of a portion of the catheter ofFIG. 3 with the balloon removed from the view.

FIG. 10 is a detail view of a stiffening element for the catheter ofFIG. 3.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

Referring toFIGS. 1-2, some embodiments of asystem100 for treating heart tissue can include a coronarysinus occlusion catheter120 and a control system140 (FIG. 2). In particular embodiments, thecontrol system140 can be configured to control the operation of thecatheter120 for providing pressure-controlled intermittent coronary sinus occlusion (PICSO) and to receive heart sensor data for display. The coronarysinus occlusion catheter120 includes a distal tip portion121 (leading to a distal end depicted inFIG. 1) and aproximal portion131, which includes aproximal hub132 that is coupled to thecontrol system140 via a number of fluid or

sensor lines

133,134, and135. Accordingly, thecontrol system140 may be employed to operate one or more components at thedistal tip portion121 of the coronarysinus occlusion catheter120 while also receiving one or more sensor signals that provide data indicative of heart characteristics (e.g., coronary sinus pressure, electrocardiogram (ECG) information, and the like).

Briefly, in use, thedistal tip portion121 of the coronarysinus occlusion catheter120 can be arranged in acoronary sinus20 of aheart10 and thereafter activated to intermittently occlude the blood flow exiting from thecoronary sinus20 and into theright atrium11. During such an occlusion of thecoronary sinus20, the venous blood flow that is normally exiting from thecoronary sinus20 may be redistributed into a portion ofheart muscle tissue30 that has been damaged due to blood deprivation. For example, the portion ofheart muscle tissue30 can suffer from a lack of blood flow due to ablockage35 in acoronary artery40. As a result, the arterial blood flow to the affectedheart muscle tissue30 via alocal artery41 can be substantially reduced such that theheart muscle tissue30 becomes ischemic or otherwise damaged. Further, because the arterial blood flow is reduced, the venous blood flow exiting from thelocal vein21 is likewise reduced.Other branch veins22 located at different regions along theheart10 may continue to receive blood flow, thereby creating a supply of venous blood flow exiting through thecoronary sinus20. In some embodiments, the coronarysinus occlusion catheter120 can be delivered into thecoronary sinus20 and thereafter activated so as to intermittently occlude thecoronary sinus20 before, during, or after treating theblockage35 on the arterial side. Such an occlusion can cause the venous blood flow to be redistributed to thelocal vein21 and then into the portion ofheart muscle tissue30 can suffer from a lack of blood flow due to ablockage35 in acoronary artery40. As such, the ischemic or otherwise damagedheart muscle tissue30 can be treated with the redistributed venous blood flow in that theheart muscle tissue30 receives redistribution of flow before, during, and after theblockage35 is repaired or removed to restore normal coronary arterial blood flow.

Furthermore, in use, the control system140 (FIG. 2) is configured to provide automated control of an occlusion component (e.g., aninflatable balloon122 or the like) of the coronarysinus occlusion catheter120. As described in more detail below, thecontrol system140 includes a computer processor that executes computer-readable instructions stored on a computer memory device so as to activate or deactivate the occlusion in thecoronary sinus20 in accordance with particular patterns. For instance, thecontrol system140 can be configured to activate the occlusion component of thecatheter120 in thecoronary sinus20 as part of a predetermined pattern of occlusion periods and release periods that is independent of the coronary sinus pressure, or as part of a pressure-dependent pattern that is at least partially defined by the coronary sinus pressure readings during the procedure. In addition, thecontrol system120 is equipped with adisplay device142 having a graphical user interface that provides a cardiologist or other user with time-sensitive, relevant data indicative of the progress of a coronary sinus occlusion procedure and the condition of theheart10. As such, the user can readily monitor the patient's condition and the effects of intermittently occluding thecoronary sinus20 by viewing the graphical user interface while contemporaneously handling the coronarysinus occlusion catheter120 other heart treatment instruments (e.g., angioplasty catheters, stent delivery instruments, or the like). It should be understood from the description herein that, in some embodiments, thecontrol system140 and the coronarysinus occlusion catheter120 can be used as part of a system for treating the heart muscle tissue before, during, and after theblockage35 is repaired or removed to restore normal coronary arterial blood flow.

Referring in more detail toFIG. 1, the coronarysinus occlusion catheter120 can be delivered via the venous system to thecoronary sinus20 before, during, or after repairing or treating theblockage35 thecoronary artery40. In such circumstances, the portion ofheart muscle tissue30 that is damaged due to lack of arterial blood flow (as a result of the blockage) can be treated with a supply of venous blood while the normal arterial blood flow is restored (as a result of repairing or removing the blockage35).

Thesystem100 may include aguide member110 that is advanced through the venous system of the patient and into theright atrium11. Theguide member110 in this embodiment comprises a guide sheath having a lumen extending between a distal end111 (FIG. 1) and a proximal end112 (FIG. 4). In alternative embodiments, theguide member110 can include a guide wire having an exterior surface extending between the distal end and the proximal end. Optionally, theguide member110 includes a steerable mechanism to control the orientation of the distal end so as to steer thedistal end111 through the venous system and into theright atrium11. Also, theguide member110 can include one or more marker bands along thedistal end111 so that the position of the distal end can be monitored during advancement using an imaging device.

After theguide member110 is advanced into theright atrium11, thedistal end111 may be temporarily positioned in thecoronary sinus20. From there, thedistal tip portion121 of the coronarysinus occlusion catheter120 can be slidably advanced along theguide member110 for positioning inside thecoronary sinus20. In the embodiments in which theguide member110 comprises a guide sheath, thedistal tip portion121 of the coronarysinus occlusion catheter120 can slidably engage with an interior surface of the lumen during advancement toward thecoronary sinus20. In the alternative embodiments in which theguide member110 comprises a guide wire structure, thedistal tip portion121 of the coronarysinus occlusion catheter120 can slidably advance over the exterior surface of the guide wire (e.g., a lumen of thecatheter120 passes over the guide wire) during advancement toward thecoronary sinus20. After the coronarysinus occlusion catheter120 reaches thecoronary sinus20, thedistal end111 of theguide member110 can be withdrawn from thecoronary sinus20 and remain in theright atrium11 during use of the coronarysinus occlusion catheter120.

Still referring toFIG. 1, thedistal tip portion121 of the coronarysinus occlusion catheter120 that is positioned in thecoronary sinus20 includes anocclusion component122, which in this embodiment is in the form of an inflatable balloon device. Theocclusion component122 can be activated so as to occlude thecoronary sinus20 and thereby cause redistribution of the venous blood into theheart muscle tissue30 that is damaged due to a lack of arterial blood flow. As described in more detail below, theinflatable balloon device122 can be in fluid communication with an internal lumen of the coronarysinus occlusion catheter120, which is in turn in communication with a pneumatic subsystem of the control system140 (FIG. 2). As such, thecontrol system140 can be employed to expand or deflate theballoon device122 in the coronary sinus.

Thedistal tip portion121 also includes atip element129 having one or more distal ports127 (FIGS. 7-8) positioned distally forward of theinflatable balloon device122. In the depicted embodiments, thedistal ports127 of thetip element129 face is a generally radially outward direction and are substantially uniformly spaced apart from one another along the circumference of the distal tip. As described in more detail below, thedistal ports127 of thetip element129 may all be in fluid communication with a singlepressure sensor lumen125 extending through the coronarysinus occlusion catheter120. Accordingly, the coronary sinus pressure can be monitored via a pressure sensor device that is in fluid communication with thedistal ports127 of thetip element129.

Referring now toFIG. 2, theproximal portion131 of the coronarysinus occlusion catheter120 and thecontrol system140 are positioned external to the patient while thedistal tip portion121 is advanced into thecoronary sinus20. Theproximal portion131 includes theproximal hub132 that is coupled to thecontrol system140 via a set of fluid or

sensor lines

133,134, and135. As such, thecontrol system140 can activate or deactivate theocclusion component122 at thedistal tip portion121 of the coronarysinus occlusion catheter120 while also receiving one or more sensor signals that provide data indicative of heart characteristics (e.g., coronary sinus pressure, electrocardiogram (ECG) information, and the like).

Theproximal hub132 of the coronarysinus occlusion catheter120 serves to connect the plurality of fluid or

sensor lines

133,134, and135 with the portion of the coronarysinus occlusion catheter120 that extends into the patient's venous system. For example, thefirst line133 extending between thecontrol system140 and theproximal hub132 comprises a fluid line through which pressurized fluid (e.g., helium, another gas, or a stable liquid) can be delivered to activate the occlusion component (e.g., to inflate the inflatable balloon device122). Thefluid line133 is connected to acorresponding port143 of the control system140 (e.g., the drive lumen port in this embodiment) so that theline133 is in fluid communication with a pneumatic control subsystem housed in thecontrol system140. Theproximal hub132 joins thefirst line133 with an inflation lumen158 (FIG. 5) extending through the coronarysinus occlusion catheter120 and to theinflatable balloon device122.

In another example, thesecond line134 extending between thecontrol system140 and theproximal hub132 comprises a balloon sensor line that is in fluid communication with the interior of theinflatable balloon device122 so as to measure the fluid pressure within theballoon device122. Theproximal hub132 joins thesecond line134 with a balloon pressure-monitoring lumen159 (FIG. 5) extending through the coronarysinus occlusion catheter120 and to theinflatable balloon device122. The pressure of theballoon device122 may be monitored an internal control circuit of thecontrol system140 as part of a safety feature that is employed to protect thecoronary sinus20 from an overlypressurized balloon device122. Theballoon sensor line134 is connected to acorresponding port144 of thecontrol system140 so that a pressure sensor arranged within thecontrol system140 can detect the fluid pressure in theballoon device122. Alternatively, the pressure sensor may be arranged in the distal tip portion121 (e.g., internal to the balloon device122) or the in theproximal hub132 such that only a sensor wire connects to thecorresponding port144 of thecontrol system140.

Still referring toFIG. 2, thesystem100 may include one ormore ECG sensors149 to output ECG signals to thecontrol system140. In this embodiment, thesystem100 includes a pair ofECG sensor pads149 that are adhered to the patient's skin proximate to theheart10. TheECG sensors149 are connected to thecontrol system140 via a cable that mates with acorresponding port149 along the housing of thecontrol system140. As described in more detail below, the ECG data can be displayed by thegraphical user interface142 in a graph form so that a cardiologist or other user can readily monitor the patient's heart rate and other characteristics while the coronary sinus is in an occluded condition and in an non-occluded condition. Optionally, thegraphical user interface142 of thecontrol system140 can also output numeric heart rate data (based on the ECG sensor data on the screen so that the cardiologist can readily view the heart rate (e.g., in a unit of beats per minutes). The ECG sensor signals that are received by thecontrol system140 are also employed by the internal control circuit so as to properly time the start of the occlusion period (e.g., the start time at which theballoon device122 is inflated) and the start of the non-occlusion period (e.g., the start time at which theballoon device122 is deflated).

In some embodiments, theblockage35 in the heart may be repaired or removed using a percutaneous coronary intervention (PCI) instrument such as an angioplasty balloon catheter, a stent delivery instrument, or the like. The PCI instrument may access the arterial system via any one of a number of PCI access points, as shown inFIG. 2. In some implementations, the PCI instrument can be inserted into the arterial system into an access point at a femoral artery, an access point at a radial artery, or an access point at a subclavian artery. Thus, as previously described, some embodiments of thesystem100 may employ a PICSO access point into the venous system while a PCI access point is employed to insert a PCI instrument into the arterial system.

Referring now toFIG. 3, thecatheter device120 carries theballoon device122 along its distal end portion. On its proximal end, thecatheter120 comprises a thehub portion132, in which the

proximal connection lines

133,134, and135 (not shown) are each connected with the respective lumens of thecatheter120 via a Y-connector139. Alternatively, a multiple outlet for a plurality of feeds may be provided. One of the twoproximal connection lines133 is connected with the lumen (e.g., inflation lumen158 (FIG. 5) serving to inflate and deflate theballoon122 and carries aproximal connection piece137 to which a fluid source may be connected. The other of theproximal connection lines134 is connected with the lumen (balloon pressure-monitoring lumen159 (FIG. 5) serving to measure the pressure internal to theballoon122, and carries aproximal connection piece137 which can be connected with an appropriate pressure measuring means. Finally, aLuer lock138 may be guided out of thehub portion132 for connection with the central lumen125 (e.g., the pressure sensor lumen) of thecatheter120.

The distance between the tip of thecatheter tip element129 and thehub portion132 is denoted by a and is, for instance, about one meter in order to enable the catheter to be introduced both via the jugular vein and via the femoral vein or the vein of the upper arm. Aprotective hose10, which can be slipped over thecatheter tip element129 and theballoon122 in the direction ofarrow11, is provided to protect theballoon122 during the storage of thecatheter120.

From the detailed view according toFIG. 2, it is apparent that theballoon122, in the inflated state, has a central, approximatelycylindrical portion152 which is adjoined by aconical portion153 on either side, saidconical portion153 being each connected with thecatheter shaft155 via a collar-shapedend piece154. In the inflated state, the diameter of theballoon122 in the region of thecylindrical portion152 may be, for instance, between about 12 mm and about 22 mm and, preferably, about 15 mm. The length b of the inflated portion of theballoon122 may be, for instance, between about 20 mm and about 30 mm and, preferably, about 25 mm. By amarker band156 positioned in theballoon122 can carry an X-ray-compatible material so as to be rendered visible during a surgery by suitable imaging processes.

In accordance with some embodiments, thecatheter shaft155 may include a plurality of lumens extending from thehub portion132 to the distal portion121 (e.g., to theballoon122 or to the tip element129). As shown in the cross-sectional illustration according toFIG. 5, thecatheter120 has the central lumen125 (e.g., the pressure sensor lumen in this embodiment) as well as two ring segment-shaped

lumens

158 and159. The ring segment-shaped lumen158 (e.g., the inflation lumen in this embodiment), which extends over a larger central angle than the ring segment-shaped lumen159 (e.g., the balloon-pressure monitoring lumen in this embodiment), thereby providing a larger arc length than the ring segment-shapedlumen159. Theinflation lumen158 likewise communicates with the interior of theballoon122 and serves to inflate and deflate theballoon122. The balloon-pressure monitoring lumen159 likewise communicates with the interior of theballoon122 and serves to measure the pressure prevailing within theballoon122.

FromFIG. 9 (which illustrates a portion of thecatheter120 that is interior to the balloon122 (with theballoon122 removed from view), it is apparent that the

lumens

158 and159 are each in communication with the interior of the balloon via two

openings

160 and161 respectively provided in an axially offset manner. The use of at least two

radial openings

160 and161 into the interior of theballoon122 can reduce the risk of the balloon prematurely covering all openings, particularly during collapsing, i.e. prior to the complete evacuation of the balloon, so that further evacuation would be rendered difficult or impossible. Between the mutually adjacent ends of the ring segment-shaped

lumens

158 and159, alumen157 having a circular cross section is arranged. Through thelumen157, electric wirings, sensors or the like can be conducted. Also, in some embodiments, in thelumen157, a stiffening wire (refer to wire25 inFIG. 7) can be arranged in the region of theballoon122, as will be described in more detail below. In addition or in the alternative, electric wirings, sensors or the like can also be conducted through thecentral lumen157.

Accordingly, the

lumens

125,157,158, and159 of thecatheter device120 may have cross-sectional geometries differing from one another. For example, theinflation lumen158 that serves to inflate and/or deflate the balloon may have a ring segment-shaped in cross section and arranged radially outside thecentral lumen125. The second lumen159 (e.g., the balloon pressure-monitoring lumen in this embodiment) may have a ring segment-shaped in cross section and arranged radially outside thecentral lumen125, and the arc-determining angle is preferably smaller as compared to the ring segment-shapedinflation lumen158. Due to the fact that the ring segment-shaped cross section of theinflation lumen158 extends over a larger central angle than the ring segment-shaped cross section of the balloon pressure-monitoring lumen159, a larger cross section is provided for theinflation lumen158 and, at the same time, separate pressure measurements will be enabled. The ability to provide pressure measurements via theseparate lumen159, for instance, has the advantage that possible buckling under flexural load (or kinking) can be detected. Buckling can be reliably detected due to the different pressures measured in theinflation lumen158 and in theseparate lumen159. In such circumstances, it is thus feasible to take the respective safety measurements, e.g. actuate a safety valve, in a prompt manner. From the cross-sectional illustration according toFIG. 6, it is apparent that a stiffening element23 in the form of a hypotube surrounds thecatheter shaft155 is arranged at a distance c (FIG. 2) from the proximal end of the balloon2. An example embodiment of the hypotube23 is illustrated inFIG. 10. As shown inFIG. 7, thestiffening wire165 made, for instance, of nitinol may be arranged in thelumen157. Thestiffening wire165 may extend over the length of theballoon122 so as to reduce the likelihood of thecatheter shaft155 buckling or otherwise deforming in the region in which it is surrounded by theballoon122, on account of the balloon pressure exerting axial upsetting forces on thecatheter shaft155.

An example embodiment of thecatheter tip element139 is illustrated in detail inFIG. 7. There, the attachment of thecollar154 of theballoon122 to the distal end of the catheter is, in particular, illustrated. The connection is realized via an interposed, distal fillingmember166, whereby a material adhesion of thecollar154 with the catheter upon interposition of the fillingmember166 is effected in this region by thermal bonding or gluing. Afurther marker band167 can be arranged at a distance d (e.g., about 6.5 mm in this embodiment) from the distal opening28 of thecatheter tip element129. Thecatheter tip element129 is connected with the distal end of the catheter by the aid of a transition piece169. It is apparent that theaxial lumen126 of thecatheter tip element129 is arranged immediately consecutive to thecentral lumen125 of the catheter. Thecatheter tip element129 comprises a portion conically tapering toward thedistal opening128 and including threeopenings127 uniformly distributed about its periphery.

From the perspective illustration according toFIG. 8, it is apparent that theedge162 of thedistal opening128 is rounded off in order to avoid damage to the vessel inner wall.

FIG. 10 depicts ahypotube123 which comprises a helical line-shapednotch163. It is apparent that the pitch of thehelix163 in thedistal end portion164 is smaller than in a more proximally locatedregion165. This results in a reduced flexural strength in thedistal end portion164 so as to enable the catheter to better follow the various curvatures of the body vessel during its introduction. In some embodiments, the pitch of thehelix163 at thedistal end portion164 relative to the pitch of the helix at the proximally locatedregion165 can be selected so that the flexural strength is a function of the length of the catheter leading up to the balloon

Thus, as described herein, thecatheter120 can be configured to provide sufficient rigidity in order to reduce the likelihood the occlusion catheter device will slip back from the occluded position because of the counter-pressure in the occluded vessel. At the same time, thecatheter120 may provide sufficient flexibility in order to enable thecatheter120 to be safely pushed forward through blood vessel regions having small radii of curvature so as to be able to position theinflatable balloon122 on thecatheter120 at the desired site of application (e.g., the coronary sinus20).

In some embodiments, the flexural strength of theballoon catheter120 is obtained by thestiffening element123 that surrounds the catheter shaft15. Thestiffening element123 also facilitates the advancement of the balloon catheter. In order reduce the likelihood of injuring the vessel during the advancement of the catheter, and to permit advancement in curved regions having small radii of curvature, thedistal end portion164 of thestiffening element123 can be positioned adjacent to the proximal end of theballoon122 and may provide a flexural strength that is reduced relative to the remaining portion of the stiffening element. Thus, a region of higher flexibility is deliberately formed at thedistal end portion164 of thestiffening element123 so as to enable the adaptation to a curved course of the body vessel during the advancement of thecatheter120, while preferably maintaining the balloon-carrying,distal portion121 of thecatheter120 in a generally parallel relationship with the longitudinal extension of the respective vessel in order to avoid injury to the vessel wall.

In particular embodiments, the stiffening element23 may extend substantially over the entire portion of thecatheter shaft155 between theballoon122 and theproximal hub portion132. In a preferred embodiment, the distance c is provided between the distal end of thestiffening element123 and the proximal end of the inflatable region of theballoon122. In the embodiment described herein, the distance c is dimensioned such that, on the one hand, the catheter shaft will not buckle between the distal end of the stiffening tube and the balloon, which would be the case with too large a distance, and, on the other hand, the flexibility and suppleness will not be limited too much in this region, which would be the case with too short a distance, or no distance at all. In some preferred embodiments, the distance c is about 4-6 mm and, in particular, about 5 mm.

As shown inFIG. 10, the stiffening element23 may be formed by a separate stainless-steel tube or also by at least one outer layer co-extruded with thecatheter shaft155 and made of a synthetic material differing from that of thecatheter shaft155. Alternatively, the stiffening element23 may be formed by a nylon tissue or comprise such a tissue. In some embodiments, the portion of the stiffening element having a reduced flexural strength extends over a length of about 30-120 mm, preferably about 40-90 mm, from the distal end of the stiffening element.

According to a preferred configuration, the hypotube23 can include at least one notch influencing the flexural strength. In the embodiment depicted inFIG. 10, thenotch163 preferably extends in a helical line-shaped manner, with the helical line or helix having a smaller pitch in the portion of reduced flexural strength of the hypotube than in the remaining portion. As described herein, further optimization is feasible in that the pitch of thehelix163 continuously increases in the portion of reduced flexural strength of the hypotube, departing from the distal end of the hypotube. Due to the continuously variable flexural strength of the hypotube in the mentioned end portion, buckling sites will be avoided.

In alternative embodiments, instead of a helical line-shapednotch163, a plurality of notches offset in the axial direction may also be provided on the stiffening element. Each of the notches can extend over a partial circumference of the hypotube, with the flexural strength depending on the axial distance between the individual notches. A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the scope of the invention. Accordingly, other embodiments are within the scope of the following claims.

Claims

What is claimed is:

1. An occlusion catheter device for intermittently occluding a coronary sinus, comprising:

a catheter shaft that carries an inflatable balloon on a distal portion;

a pressure sensor lumen extending centrally through the catheter shaft to a plurality of distal ports that are positioned distally of the balloon for communication with fluid in a coronary sinus;

an inflation lumen to inflate and deflate the balloon;

a stiffening element extending along the catheter shaft, the stiffening element having a distal end portion that is positioned adjacent to the proximal end of the balloon and has a flexural strength reduced relative to a remaining proximal portion of the stiffening element.

2. The catheter device ofclaim 1, wherein the stiffening element comprises a hypotube surrounding the catheter shaft.

3. The catheter device ofclaim 2, wherein the stiffening element substantially extends over the entire portion of the catheter shaft between the balloon and a proximal hub portion.

4. The catheter device ofclaim 2, wherein the distal end portion of the stiffening element having the reduced flexural strength extends over a length of about 40 mm to about 90 mm.

5. The catheter device ofclaim 2, wherein the hypotube comprises at least one notch influencing the flexural strength.

6. The catheter device ofclaim 5, wherein the notch extends in a helical line-shaped manner, with the helical line having a smaller pitch in the distal end portion of the stiffening element having the reduced flexural strength than in the remaining proximal portion of the stiffening element.

7. The catheter device ofclaim 5, wherein the pitch of the helical line continuously increases in the distal end portion of the stiffening element having the reduced flexural strength, departing from the distal end of the hypotube.

8. The catheter device ofclaim 1, wherein the lumens extending through the catheter shaft have cross-sectional geometries differing from one another.

9. The catheter device ofclaim 8, wherein the inflation lumen has a ring segment-shaped in cross section and is arranged radially outside the pressure sensor lumen extending centrally through the catheter shaft.

10. The catheter device ofclaim 9, further comprising wherein a balloon pressure-monitoring lumen to measure the pressure in the balloon, the balloon pressure-monitoring lumen having a ring segment-shaped in cross section and being arranged the pressure sensing lumen extending centrally through the catheter shaft, wherein an arc-determining angle of the balloon pressure-monitoring lumen is smaller as compared to that of the inflation lumen.

11. The catheter device ofclaim 10, further comprising a circular or oval lumen provided between the neighboring ends of the ring segment-shaped cross sections of the inflation lumen and the balloon pressure-monitoring lumen.

12. The catheter device ofclaim 10, wherein the inflation lumen and the balloon pressure-monitoring lumen are each connected with the interior of the balloon via at least two radial openings arranged to be offset in an axial direction of the catheter shaft.

13. The catheter device ofclaim 1, further comprising a stiffening wire extending through a lumen of the catheter shaft in a region adjacent to the balloon, said wire extending along a length of the balloon.

14. The catheter device ofclaim 1, further comprising a catheter tip element in fluid communication with the pressure sensor lumen extending centrally through the catheter shaft, the catheter tip element defining the plurality of distal ports that are positioned distally of the balloon for communication with fluid in a coronary sinus, the plurality of distal ports comprising a plurality of radial openings that are substantially uniformly distributed over a circumferential periphery of the catheter tip element.

15. The catheter device ofclaim 14, wherein a distal edge of a distal opening of the catheter tip element is rounded off.

16. The catheter device ofclaim 15, wherein the catheter tip element conically tapers toward the distal opening.

17. The catheter device ofclaim 14, wherein the catheter tip element comprises a flexible material.

18. The catheter device ofclaim 14, wherein a distance between a distal end of the catheter tip element and the distal end of the inflatable portion of the balloon is about 35 mm to about 45 mm.

19. A coronary sinus occlusion catheter device, comprising:

a catheter shaft that carries an inflatable balloon on a distal portion;

an inflation lumen to inflate and deflate the balloon; and

a balloon pressure-monitoring lumen to measure the pressure in the balloon, the balloon pressure-monitoring lumen being different from and adjacent to the inflation lumen, wherein both the inflation lumen and the balloon pressure-monitoring lumen are in fluid communication with an interior of the balloon.

20. The catheter device ofclaim 1, further comprising a stiffening element extending along the catheter shaft, the stiffening element having a distal end portion that is positioned adjacent to the proximal end of the balloon and has a flexural strength reduced relative to a remaining proximal portion of the stiffening element.