ASSEMBLY COMPRISING A SUCTION LINE, A PRESSURE LINE AND A PUMP

Abstract

An assembly for an extracorporeal life support system with a suction line that features a venous cannula and a pressure line that features an arterial cannula furthermore includes a pump that is arranged between the suction line and the pressure line. This assembly has a discharge line with a discharge cannula, wherein the discharge cannula is longer than the arterial cannula, and wherein the discharge line is connected to the suction line or the pressure line.

Claims

1. An assembly for an extracorporeal life support system with a suction line (3) that features a venous cannula (4), a pressure line (13) that features an arterial cannula (12), a pump (8) that is arranged between the suction line (3) and the pressure line (13, 30) and a discharge line (19, 23) with a discharge cannula (20), wherein the discharge cannula (20) is realized in the form of a ventilation cannula, wherein the discharge line (19) is connected directly to the suction line (3) or directly to the pressure line (13), and wherein only a single pump and no reservoir is arranged between the suction line and the pressure line, wherein the discharge cannula (20) is longer than the arterial cannula (12) and an oxygenator (10) is arranged between the suction line (3) and the pressure line (13).

2. The assembly according to claim 1, wherein the pump (8) generates a pulsating flow.

3. The assembly according to claim 1, wherein the discharge line (19) features a flow restrictor (22).

4. The assembly according to claim 2, wherein the flow restrictor (22, 25) can be automatically adjusted in dependence on the pulsating flow.

5. The assembly according to claim 1, wherein a Y-adapter (6, 28) is arranged between the discharge line (19) and the suction line (3) or the pressure line (13).

6. The assembly according to claim 1, wherein the discharge line (19) is connected to the pressure line (13) and features a check valve (26).

7. The assembly according to claim 1, wherein the discharge line (19) is connected to the pressure line (13) by means of a Venturi nozzle (29).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Several exemplary embodiments of inventive assemblies are illustrated in the drawings and described in greater detail below. In these drawings,

[0024] FIG. 1 shows an extracorporeal life support system, in which the discharge line leads into the suction line,

[0025] FIG. 2 shows an extracorporeal life support system, in which the discharge line leads into the pressure line,

[0026] FIG. 3 shows a detail of the extracorporeal life support system according to FIG. 1 with a second pump,

[0027] FIG. 4 shows an extracorporeal life support system according to FIG. 2 with a second pump,

[0028] FIG. 5 shows an assembly according to FIG. 4 with a Y-adapter,

[0029] FIG. 6 shows the routing of a pressure line and a smaller discharge line in a cannula,

[0030] FIG. 7 shows a cross section through the routing of a discharge line in a cannula,

[0031] FIG. 8 shows a longitudinal section through the cannula routing illustrated in FIG. 7,

[0032] FIG. 9 schematically shows bilateral access of the discharge cannula,

[0033] FIG. 10 schematically shows access of the discharge cannula through a vena brachialis,

[0034] FIG. 11 schematically shows access of the discharge cannula through the superior vena cava and an atrial septum, and

[0035] FIG. 12 schematically shows access of the discharge cannula through the inferior vena cava and an atrial septum.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0036] According to the first exemplary embodiment illustrated in FIG. 1, the extracorporeal life support system 1, 2 has a suction line 3 that features a venous cannula 4 with bores 5, a Y-adapter 6 and a feed line 7 leading to a pump 8. Only the pump head of the pump 8 is illustrated in this figure. The pump 8 is connected to an oxygenator 10 by means of a connecting line 9, wherein the oxygenator is connected to an arterial cannula 12 by means of a delivery line 11. The delivery line 11 and the arterial cannula 12 form a pressure line 13.

[0037] While the assembly is in use, blood can therefore be drawn from the heart 14 to the pump 8 through the vena femoralis 15 by means of the venous cannula 4 of the suction line 3 in order to be subsequently conveyed into the left ventricle via the oxygenator 10 and the arterial cannula 12, namely through the arteria femoralis 16 and the aorta via the aortic arch. In this way, the heart 14 is bypassed and therefore relieved.

[0038] If a pulsatile pump 8 is used, an overpressure is generated in the arteria femoralis 16 at the moment of maximum pressure and presses against the wall 17 of the heart. It is therefore advantageous to reduce the pressure in the region 18 behind the wall 17 of the heart at this moment by removing blood by suction. This is achieved with a discharge line 19 that comprises a discharge cannula 20 and a discharge line 21. This discharge cannula 20 makes it possible to convey blood from the heart 14 through the arteria femoralis 16 and to the Y-adapter 6, from where the blood reaches the pump 8 through the feed line 7. Consequently, the pump 8 not only draws blood from the venous cannula 4, but also from the discharge cannula 20. Even without a suction effect, the discharge cannula already serves for relieving an overpressure and therefore the heart.

[0039] The volume flow being returned through the discharge line 19 can be varied by means of the flow restrictor 22. The flow restrictor 22 may be provided optionally and is connected to a (not-shown) control that controls or adjusts the flow through the discharge line 19 and the pump 8. In this way, the discharge can be arbitrarily varied and, in particular, controlled in dependence on the pumping capacity during the operation of the pump while the assembly is in use. According to a preferred embodiment, it is proposed that the pumping capacity and therefore also indirectly the flow restrictor are controlled in dependence on the heart rhythm, i.e. the EKG-signal.

[0040] The alternative embodiment of the assembly 2 illustrated in FIG. 2 is essentially designed and used in the same way as the assembly illustrated in FIG. 1. However, the discharge line 23 features a discharge cannula 24 that is connected to a Y-adapter 28 by means of a flow restrictor 25, a check valve 26 and a line 27. In the present exemplary embodiment, the Y-adapter 28 is realized in the form of a Venturi nozzle 29. This allows a simplified design without a check valve 26 and without a flow restrictor 25 because the Venturi nozzle also causes a stronger vacuum and therefore greater suction on the discharge line 23 at the moment of an increased flow through the pressure line 30.

[0041] As in the exemplary embodiment illustrated in FIG. 1, the cannula inlet 31 of the discharge line 23 of the discharge cannula 24 lies in the region 18 behind the aortic valve 32 and the aortic arch 33 while the cannula is in use.

[0042] FIG. 3 shows an embodiment that is essentially designed in the same way as the embodiment illustrated in FIG. 1. However, a pump 34, which is preferably realized in the form of a suction pump, is provided between the discharge line 19 and the Y-adapter 6 in this exemplary embodiment. This pump in the form of a suction pump can be activated independently of the pump 8. It may consist of a non-pulsatile or pulsatile pump and be operated synchronously with the pump 8 or phase-shifted relative to the pump 8. In this case, the pump 8 fulfills the function of the main pump and the pump 34 fulfills the function of an assist pump.

[0043] An additional pump 35 is also provided between the discharge line 23 and the Y-adapter 28 in FIG. 4, which shows an exemplary embodiment according to FIG. 2. An EKG-triggered pulsatile control with or without additional suction pump 35 is also advantageous in this exemplary embodiment.

[0044] A pump control 37 is provided for this purpose and connected to the pump 8 and—if applicable—to an additional pump 35 (see FIG. 4) or an additional pump 34 (see FIG. 3). A computer 38 converts a control signal 39 into a pump driving signal 40, 41. This pump driving signal is used by the pump control 37 for realizing a pumping capacity of the pump 8, which increases and decreases in waves, and can furthermore ensure a synchronous or time-shifted and pulsatile or not-pulsatile pumping capacity of the pumps 34 or 35, which may also be dependent on or independent of the pumping capacity of the main pump 8. The control signal 39 is generated by an EKG 42 that is connected to the patient 44 by means of a cable 43.

[0045] During the operation of the ECLS system, an EKG-signal of the patient 44 is acquired with the EKG 42 via the cable 43 in order to generate the control signal 39. This control signal 39 is converted into the pump signal 40, 41 by means of the computer 38 and serves for controlling the pumps 8, 34 and 35 by means of the pump control 37 or for supplying said the pumps with power. This makes it possible to realize an SW-trigger for operating the pumps in accordance with a special algorithm in order to deliver pulses during the systole and/or the diastole. A device and a method of this type are described in EP 2 832 383 and the corresponding description forms part of this application.

[0046] In the exemplary embodiment illustrated in FIG. 4, a spacer 36 is provided on the end 31 of the discharge cannula 24. This spacer 36 prevents the cannula inlet 31 from being sucked against the wall 17 of the heart. This can be realized with a cage-like design or a spiral-shaped design of the end 31, which is also referred to as pigtail.

[0047] In all exemplary embodiments, the venous cannula 4 has a length of 55 cm and a preferred size between 19 Fr and 25 Fr. The cannula has a size, for example, between 21 and 25 Fr. The arterial cannula preferably has a length of 38 cm and a size between 13 Fr and 17 Fr, preferably between 15 and 16 Fr. The discharge cannula is smaller than the venous cannula and smaller than the arterial cannula. It has a size between 7 Fr and 9 Fr and a length of 90 cm.

[0048] FIG. 5 shows a slightly enlarged illustration of a Y-adapter 50, in which the discharge cannula 24 can be inserted into the pressure line 30 in the form of a ventilation cannula such that it is not required to route two cannulas adjacent, to one another in the vessel. The ventilation cannula is realized with a size of 6, 7 or 8 Fr and the adjacent branch 51 has a size of ⅜″. The cannula shaft 52 of the perfusion cannula routed in the indicated aorta 53 has a size of 13, 16 or 18 Fr and the ventilation cannula 24 is inserted therein in a floating fashion.

[0049] In the exemplary embodiment illustrated in FIG. 6, the ventilation cannula 62 and the pressure line 63 are routed within the wall 60 of a catheter 61. For this purpose, the ventilation cannula 62 is inserted into the Y-inlet 64 and then routed adjacent to the pressure line 63. According to a not-shown embodiment, the ventilation cannula 62 is inserted into the pressure line 63 and then routed within the pressure line 63.

[0050] FIGS. 7 and 8 show how a ventilation cannula 17 can be routed in an inner cannula lumen 71. In this case, a working channel 72 for the ventilation cannula 70 is provided in the lumen 71. The wall of the cannula may be thickened in the region of the working channel 72 if the wall is not sufficiently thick for arranging a working channel therein.

[0051] FIGS. 9-12 show how a discharge or ventilation cannula can be routed in the body 80 of a patient. The lengths and designs of the cannula differ depending on the respective routing.

[0052] In the example illustrated in FIG. 9, the suction line 82 is venously inserted and the pressure line 83 is arterially inserted into a leg 81. The discharge line 84 is routed in the other leg 85.

[0053] In the example illustrated in FIG. 10, the suction line 82 is venously inserted and the pressure line 83 is arterially inserted into a leg 81. The discharge line 84 is routed in the arteria brachialis.

[0054] FIGS. 11 and 12 show access through an atrial septum 86. In this case, the ventilation cannula 84 is either routed through the superior vena cava 87 as shown in FIG. 11 or through the inferior vena cava 88 as shown in FIG. 12. The atrial septum 86 lies between the atria 89 and 90.

[0055] The embodiments shown relieve the heart, particularly in case of insufficient pumping capacity or output capacity. The myocardium-protective effect of the diastolic augmentation significantly intensifies, in particular, during a pulsatile EKG-triggered operation of one or both pumps (lower afterload, increase of the left ventricular output capacity, reduction of the left ventricular residual volume) due to the reduced ventricle volume. This additionally relieves the left ventricle and lowers the wall tension, especially during the diastole, such that the coronary flow can be positively influenced.