WO2016008521A1

WO2016008521A1 - Right heart support system

Info

Publication number: WO2016008521A1
Application number: PCT/EP2014/065268
Authority: WO
Inventors: Hans Reiner Figulla; Alexander Lauten
Original assignee: Universitätsklinikum Jena
Priority date: 2014-07-16
Filing date: 2014-07-16
Publication date: 2016-01-21
Also published as: EP3169383A1

Abstract

The present invention relates to an implantable right heart support system (10), comprising at least one stent graft (11), which has a first longitudinal end (12) for fastening in the inferior vena cava (31) and a second longitudinal end (13) for fastening in the pulmonary artery (33), wherein at least two inflatable and deflatable balloons (20, 21, 22) are arranged inside the stent graft (11), said balloons being positioned one behind the other coaxially and being controlled in such a way that a pulsatile blood flow through the stent graft (11) is produced, and wherein an inlet valve (14) is arranged at the first longitudinal end (12) of the stent graft (11) and an outlet valve (15) is arranged at the second longitudinal end (13) of the stent graft (11). The invention further relates to a surgical implantation set having such a right heart support system.

Description

RIGHT HEART SUPPORT SYSTEM

description

The invention relates to a right heart support system and a surgical implantation set with such a right heart support system.

One of the most common diseases in industrialized countries is so-called heart failure. The pumping power of the heart is reduced, which can lead to a shortage of other organs with oxygen and nutrients, at least under stress. The medical treatment of heart failure is limited, so that in severe cases mechanical heart support systems are used. From the practice of such cardiac assist systems are known, in particular microaxial pumps are used.

The principle of micro-axial pumps is to promote blood within blood vessels by high rotation of turbine-like paddle wheels.

Such micro-axial pumps operate at high speeds of several thousand revolutions per minute to allow a sufficient pumping power despite the small diameter.

This has some disadvantages. On the one hand, the high rotational speeds of the micro-axial pumps lead to a local increase in temperature, which can permanently cause tissue damage. On the other hand, the blood gets through the high Speeds exposed to high shear forces, which leads to destruction or damage of blood components. Finally, micro-axial pumps operate on a completely different principle of operation than the natural pumping action in the circulatory system dictates. The heart as a natural pump causes a pulsating blood flow, which ultimately leads to a comparatively laminar flow as a result of the aorta's vesicular function. In contrast, a microaxial pump delivers continuously and can not replicate such a pulsating blood flow. Overall, there is a need for a cardiac assist system whose mode of action is closer to the physiological model.

The object of the invention is to provide a right heart support system that allows efficient relief of the heart, in particular the right heart, has a simple structure and adapts well to the physiology of the human cardiovascular system. It is a further object of the invention to provide a surgical implant set having such a right heart assist system.

According to the invention this object is achieved with regard to the right heart support system by the subject of claim 1 and with regard to the Implantationsset by the subject of claim 14.

The invention is based on the idea of specifying an implantable right heart support system with at least one stent-graft, which has a first longitudinal end for fixation in the inferior vena cava and a second longitudinal end for fixation in the pulmonary artery. Within the stent-graft, at least two inflatable and deflatable balloons are arranged, which are positioned coaxially behind one another and are controlled such that a pulsatile blood flow is generated by the stent-graft. An outlet valve is located at the first length of the stent-graft and an outlet valve at the second longitudinal end of the stent-graft.

The invention makes use of the principle of displacement of liquids by means of balloon inflation. By suitable control of the individual balloons they can be inflated with a time delay to each other, resulting in a wave-shaped displacement of liquids, in particular blood here. Thus, the pulsatile blood flow, which occurs naturally in the cardiovascular system, can be replicated. In particular, those within the stent-graft serve this purpose arranged inflatable balloons, which are inflatable or expandable against the inner wall of the stent-graft and thus lead to a Verdrängu ng of blood within the stent-graft. In this case, the valves arranged at the longitudinal ends each act as check valves in a flow direction and as sluices in the other flow direction. In this way, the flow direction of the blood displaced by the balloons can be influenced.

Particular advantages arise when the inlet valve and the outlet valve are each formed by heart valve prostheses. Such heart valve prostheses have already been tried and tested for a long time and therefore have a high level of reliability. In addition, they meet the corresponding requirements for biocompatibility.

In a preferred embodiment of the right heart support system according to the invention, the first longitudinal end has a cross-sectional diameter which substantially corresponds to the inner diameter of the lower vena cava. The right heart assist system is preferably implanted between the inferior vena cava and the pulmonary artery, thus traversing the right ventricle of the heart. In this way, the heart should be relieved. In other words, it is provided to direct a portion of the blood to be pumped through the stent-graft, so that the natural heart only has to apply part of the pumping power. It is particularly advantageous if the stent-graft is fully implanted with its first longitudinal end in the inferior vena cava and completely absorbs the blood volume originating from the inferior vena cava. Thus, for the natural heart, only the blood volume originating from the superior vena cava, which must be pumped by the right ventricle, remains. The inferior vena cava is pumped into the pulmonary artery via the right ventricular assist system. By having the first longitudinal end of the stent-graft having a cross-sectional diameter that matches the cross-sectional diameter of the inferior vena cava, it is ensured that the villous volume from the inferior vena cava is completely guided into the stent-graft.

The stent graft may include a vena cava section, a ventricular section, and a pulmonary artery section in each of which a balloon is disposed. In the different sections, the stent-graft may have different structural characteristics. Thus, the stent-graft can For example, be formed of a lattice structure, wherein in the vena cava and the pulmonary artery section, the lattice structure has a relatively large mesh size. This can lead to an improved anchoring of the stent graft in the inferior vena cava or in the pulmonary artery. In the ventricular segment, the mesh size of the stent-graft may be comparatively small in order to provide good stability of the ventricular segment. In each of the aforementioned sections, in particular in the vena cava section, in the ventricular section and in the pulmonary artery section, a balloon may be arranged in each case.

Overall, so three balloons can be provided, which improves the pumping power of the right heart support system.

In a further preferred embodiment of the invention, the vena cava section, the ventricular section and the pulmonary artery section have different cross-sectional diameters. In particular, at least one of the aforementioned sections may have a different cross-sectional diameter than one or more further sections. For example, it can be provided that the ventricular section has a larger cross-sectional diameter than the vena cava section and / or the pulmonary artery section. The cross-sectional diameters of the vena cava section and the pulmonary artery section may be limited by the internal diameters of the respective blood vessels, in this case the inferior vena cava and the pulmonary artery. The ventricle portion, however, may have a larger cross-sectional diameter, which is advantageous for increasing the pumping capacity. Furthermore, the balloons may have different cross-sectional diameters in different sections of the stent-graft. In particular, a balloon which is arranged in the ventricle section may have a different, in particular larger, cross-sectional diameter than edge-side balloons which are arranged in the vena cava section or in the pulmonary artery section. In this regard, it should be noted that the cross-sectional diameters and other dimensions of the balloons refer to the maximum inflated state, respectively. The maximum inflated state thus arises when the balloons are arranged outside the stent-graft and completely inflated. In the implanted state, ie when the balloons are arranged inside the stent graft, the cross-sectional diameter of the balloons is limited by the contact with the stent graft. It can also be provided that at least one of the balloons, in particular all balloons, each individually have a sectionally varying cross-sectional diameter. In particular, individual or all balloons may each have an outer contour, which is adapted to the anatomical conditions at the implantation site. As such, the cross-sectional diameter can vary along a single balloon. Preferably, the outer dimension of the individual balloons is adapted so that the largest possible displacement volume is provided. Thus, the greatest possible displacement of blood volume can be achieved, which enables an increase in the time volume of the right heart support system.

In a further preferred embodiment of the invention, it is provided that the stent-graft comprises a liquid-impermeable wall. This ensures that the blood volume displaced by the individual balloons is directed completely towards the pulmonary artery. Overall, this increases the pumping power of the right heart support system.

The stent-graft, in particular the liquid-impermeable wall, may also have at least one lateral inlet valve. This allows the influx of blood in all sections of the stent-graft and increases the support effect or improves the relief of the natural heart muscle.

The lateral intake valve or the plurality of lateral intake valves may be arranged in particular in the ventricle section. It can thus be achieved that blood which flows via the upper vena cava into the ventricle, ie the right ventricle, is pumped through the right heart support system into the pulmonary artery. By also detecting blood volume from the superior vena cava by the right ventricular assist system in addition to the blood volume from the inferior vena cava, the burden on the natural cardiac muscle is further reduced. Overall, this increases the relief effect.

With regard to the lateral inlet valves, it may also be provided that they are aligned in a line parallel to a longitudinal axis of the stent-graft. Alternatively, the side inlet valves may be distributed over a circumference of the stent graft. Aligning the lateral inlet valves in a line parallel to the longitudinal axis of the stent-graft makes it possible to align all lateral inlet valves with, for example, the outlet opening of the superior vena cava. so that a uniform inflow of blood from the superior vena cava into the right heart support system, in particular in the ventricular portion of the stent-graft, is made possible. However, this requires precise alignment of the stent-graft during implantation. A simpler placement of the stent-graft is therefore achieved with the alternative design, according to which the lateral inlet valves are distributed over a circumference of the stent-graft. In this way it is achieved that, regardless of the implantation position of the stent-graft, at least one inlet valve points in the direction of the right atrium or the superior vena cava and thus a direct inflow of blood from the upper vena cava is ensured.

In order to further improve the peristaltic effect of the blood-promoting balloons, it can be provided that the balloons each have a plurality of chambers which can be inflated individually, in particular sequentially. With suitable activation, this results in a peristaltic pumping movement, which leads to an improved delivery of blood and thus allows a high time volume.

In the invention, in advantageous embodiments, a controller is provided which controls deflation and inflation of the balloons in a time-shifted manner such that a peristaltic pumping movement is set along the balloons which propagate from the first longitudinal end of the stent graft to the second longitudinal end. On the one hand, such a peristaltic pumping movement forms well the pulsatile blood flow, which naturally occurs in the circulatory system, and, in contrast to known microaxial pumps, considerably reduces the shear forces acting on the blood.

A side-by-side aspect of the invention is to provide a surgical implant set having a right heart assist system and a catheter as described above, wherein the catheter is adapted for insertion of the right ventricular assist system via a femoral vein. Access via a femoral vein is preferred for direct access to the inferior vena cava. The catheter used for this purpose should have a length sufficient to be guided from the access point at the femoral vein to the right ventricle, ie to the right ventricle.

The invention will be explained below with reference to an embodiment with reference to the accompanying schematic drawing. It shows the single figure is a schematic cross-sectional view of the inventive right heart support system according to a preferred embodiment in the implanted state. In the attached figure, a section through a heart is shown, which has two chambers 30, 34, wherein the chambers 30, 34 are separated by a heart septum 35 from each other. In this case, a right ventricle 30 is separated from a left ventricle 34. In the region of the left ventricle 34, a mitral valve 36 and an aortic valve 37 can also be seen, with the aortic valve 37 separating the left ventricle 34 from an aorta 38.

With regard to the right half of the heart, a section through the right ventricle 30 and the right atrium 39 is shown. In the right atrium 39 opens an upper vena cava 32 (superior vena cava) and a lower vena cava 31 (vena cava inferior). A pulmonary artery also branches off from the right ventricle 30, which crosses over with the aorta 38.

The right heart assist system 10 is shown in the illustrated embodiment in the implanted state. The right heart assist system 10 includes a stent graft 11 that is substantially tubular. The stent-graft 11 comprises two longitudinal ends 12, 13, wherein a first longitudinal end 12 in the inferior vena cava 31 and a second longitudinal end 13 in the upper vena cava 32 is arranged. In particular, the stent-graft 11 can be subdivided into three different sections. The stent-graft 11 has a vena cava section 16, which is positioned in the inferior vena cava 31 in the implanted state. Furthermore, the stent graft 11 comprises a pulmonary artery section 18, which comes to rest in the implanted state in the pulmonary artery 33.

A ventricular section 17 extends between the vena cava section 16 and the pulmonary artery section 18. The ventricular section 17 is arranged in the right ventricle 30 in the implanted state.

As can be seen in the figure, the stent-graft 11 at the longitudinal ends 12, 13 each have a valve. In particular, an inlet valve 14 is provided at the first longitudinal end 12. At the second longitudinal end 13, the stent-graft 11 comprises an outlet valve 15. The inlet valve 14 and the outlet valve 15 are preferably designed such that a blood flow in only one direction through the inlet valve 14 and outlet valve 15 is possible. In particular, a blood stream from the inferior vena cava 31 to the pulmonary artery 33, while blocking blood flow in the opposite direction.

In particular, the inlet valve 14 and the outlet valve 15 allow complete closure of the lumen of the stent-graft 11 to prevent backflow of blood.

Within the stent-graft 11 three balloons 20, 21, 22 are arranged. In the vena cava section 16, a vena cava balloon 20, a ventricular balloon 21 in the ventricular section 17, and a pulmonary artery bile ion 22 in the pulmonary artery section 18 are arranged. The balloons 20, 21, 22 are preferably interconnected with each other, wherein each individual balloon 20, 21, 22 is separately inflatable.

Furthermore, it can be seen in the accompanying drawing that the balloons 20, 21, 22 have different outer contours. It can be provided that the vena cava balloon 20 has a length which is greater than the length of the pulmonary artery balloon 22. It is also conceivable that the vena cava balloon 20 and the pulmonary artery balloon 22 comprise the same length. It is preferably provided that the ventricular balloon 21 has a larger cross-sectional diameter in the inflated state than the vena cava balloon 20 and / or pulmonary artery balloon 22. Thus, the available volume in the right ventricle 30 can be exploited to allow greater blood displacement in the ventricular segment 17.

In addition, lateral inlet valves 23 are provided in the ventricle section 17 and are aligned essentially with respect to the right atrium 39. The lateral ones

Inlet valves 23 operate in substantially the same manner as the inlet valve 14 at the first longitudinal end 12 of the stent-graft 11. Specifically, the side inlet valves 23 allow the flow of blood from the right atrium 39 into the stent-graft 11, but block backflow of blood the stent-graft 11 in the right atrium 39. The lateral inlet valves 23 are formed in particular in a wall 19 of the stent-graft 11. The wall 19 of the stent-graft is preferably formed fluid-impermeable to ensure a safe and reliable delivery of blood through the stent-graft 11. The right heart assist system 10 provides support for the right ventricle 30 in patients with acute or chronic right heart failure. The delivery of the implantable right heart support system 10 is preferably via a catheter which is advanced via the femoral vein into the inferior vena cava 31 and the right heart support system 10 at the implantation site in the region of the right ventricle 30 releases. The pumping assistance of the right ventricle 30 is performed in the right heart support system 10 by a peristaltic pumping movement, which is made possible by sequentially inflating and deflating the individual balloons 20, 21, 22. In this case, provision is made, in particular, to use comparatively short balloons 20, 21, 22 in order to avoid stretching of the catheter during balloon inflation. In other words, the balloons 20, 21, 22 are formed so short in their length that a deleterious extension via the femoral vein inserted catheter is avoided. The inflation and deflation of the individual balloons 20, 21, 22 is preferably cyclic during ventricular systole and diastole. The activation of the individual balloons 20, 21, 22 preferably takes place in such a way that the natural pulse wave frequency is imaged.

LIST OF REFERENCE NUMBERS

10 right heart support system

11 stent-graft

12 first longitudinal end

13 second longitudinal end

14 inlet valve

15 exhaust valve

16 vena cava section

17 ventricle section

18 Pulmonary artery section

19 wall

20 vena cava balloon

21 ventricular balloon

22 Pulmonary artery balloon

23 side inlet valve

30 right ventricle

31 inferior vena cava

32 upper vena cava

33 pulmonary artery

34 left ventricle

35 cardiac septum

36 mitral valve

37 aortic valve

38 aorta

39 right atrium

Claims

claims

1. Implantable right heart support system (10) with at least

a stent-graft (11) having a first longitudinal end (12) for fixation in the inferior vena cava (31) and a second longitudinal end (13) for fixation in the pulmonary artery (33), wherein within the stent-graft (11) at least two inflatable and deflatable balloons (20, 21, 22) are positioned coaxially one behind the other and are controlled such that a pulsatile blood flow is generated by the stent-graft (11) and at the first longitudinal end (12) of the stent -Grafts (11) an inlet valve (14) and at the second longitudinal end (13) of the stent-graft (11) an outlet valve (15) is arranged.

2. right heart support system (10) according to claim 1,

dad u rch g eken nzeich net that

the inlet valve (14) and / or the outlet valve (15) is each formed by a heart valve prosthesis.

3. right heart support system according to claim 1 or 2,

dad u rch g eken nzeich net that

the first longitudinal end (12) of the stent-graft (11) has a cross-sectional diameter substantially equal to the inner diameter of the inferior vena cava (31).

4. right heart support system (10) according to any one of the preceding claims,

dad u rch g eken nzeich net that

the stent-graft (11) has a vena cava section (16), a ventricular section (17) and a pulmonary artery section (18), in each of which a balloon (20, 21, 22) is arranged.

5. right heart support system (10) according to claim 4,

dad u rch g eken nzeich net that

the vena cava section (16), the ventricular section (17) and the pulmonary artery section (18) have different cross-sectional diameters.

6. right heart support system (10) after one of the preceding

Claims,

dad u rch g eken nzeich net that

the balloons (20, 21, 22) have different cross-sectional diameters in different sections of the stent-graft (11).

7. right heart support system (10) according to one of the preceding

Claims,

dad u rch g eken nzeich net that

at least one of the balloons (20, 21, 22) has a sectionally varying cross-sectional diameter.

8. right heart support system (10) after one of the preceding

Claims,

dad u rch g eken nzeich net that

the stent-graft (11) comprises a liquid-impermeable wall (19).

9. right heart support system (10) according to one of the preceding

Claims,

dad u rch g eken nzeich net that

the stent-graft, in particular the liquid-impermeable wall, at least one lateral inlet valve (23).

The right heart assist system (10) according to claim 9,

dad u rch g eken nzeich net that

the lateral inlet valve (23) is arranged in the ventricle section (17).

11. right heart support system (10) according to any one of the preceding claims,

dad u rch g eken nzeich net that

a plurality of lateral inlet valves (23) are provided which are aligned in a line parallel to a longitudinal axis of the stent-graft (11) or distributed over a circumference of the stent-graft (11).

12. right heart support system (10) according to any one of the preceding claims,

dad u rch g eken nzeich net that

the balloons (20, 21, 22) each have a plurality of chambers which are individually, in particular sequentially, inflatable.

13. right heart support system (10) according to any one of the preceding claims,

dad u rch g eken nzeich net that

a controller is provided which controls deflation and inflation of the balloons (20, 21, 22) in a time-shifted manner such that a peristaltic pumping movement is set along the balloons (20, 21, 22) extending from the first longitudinal end (12) of the balloon Stent-graft (11) to the second longitudinal end (13) propagates.

14. A surgical implant set comprising a right heart assist system (10) according to any one of the preceding claims and a catheter for insertion of the right ventricular assist system via a femoral vein.