A SINGLE LUMEN VENO VENOUS ECMO (EXTRACORPOREAL MEMBRANE OXYGENATION) CANNULA

TECHNICAL FIELD

The present invention relates to a single-inflow, single lumen, multiple-outflow cannula for venovenous ECMO (Extracorporeal Membrane Oxygenation).

PRIOR ART

Extracorporeal membrane oxygenation (ECMO) is an extracorporeal life support method employed in patients of all age groups who suffer from heart, circulatory, and/or respiratory failure and do not respond to conventional treatment methods. The ECMO system incorporates drawing venous (outflow) blood from a patient's body by using cannula or cannulae and infusing arterial (inflow) blood back into the patient's body after venous blood is subjected to gas exchange and oxygenation.

Particularly the cannulae used for venovenous ECMO in pediatric age groups may suffer performance issues stemming from the insufficiency of blood drawing and blood infusion capacities. Overcoming this issue requires using larger cannulae according to patients' sizes. While insertion problems are experienced accordingly, the administration imposes a risk of causing further injury in a patient's heart, vessels and organs in close proximity. Moreover, an echocardiography device is utilized with the aim of confirming that the cannulae inserted with difficulty are indeed properly positioned, and the use of this device requires distinct experience. Furthermore, even in cases where proper positioning is achieved with the cannula, the smallest movement of the patient may cause the cannula to become dislocated from the desired position, which in turn requires repositioning. Additionally, extended periods of cannulae remaining in patients brings along a risk for catheter infection.

In the state of the art, ECMO cannulae may generally be placed through venovenous (vv), venoarterial (va), or venovenoarterial (vva) routes, or placement thereof may be performed in various ways and types apart from those named above. The administration of ECMO cannulae may be peripheral or central.

Peripheral ECMO may be performed via the cannulation of Internal Jugular Vein (IJV) and Femoral Vein/artery and arteries. Peripheral vv ECMO may be carried out through the cannulation of IJV and Femoral Vein. Peripheral va/wa ECMO may be performed via the cannulation of IJV and Femoral Vein/artery.

As the peripheral vv ECMO may be performed through two vessels, namely, two veins by using two cannulae, it may also be carried out by means of a single cannula with double lumen through the IJV. Central ECMO, on the other hand, is an ECMO application performed through the right atrium of the heart, and the aorta.

A characteristic of the cannula used for vv ECMO nowadays and placed through the IJV is that this cannula comprises a tip orifice, and at distal part of this orifice, a plurality of holes that are located in a manner distributed around the cannula. Blood cleansed in the ECMO machine is transferred to the right atrium of a patient through these holes. During the transfer process, blood, which exits the tip of the cannula, and is sent to the right atrium via injection, is directed towards the cannula, which is located in the inferior vena cava, and receives blood, thereby performing recirculation. This recirculation leads to a redundant circulation of blood inside the machine, to working of the blood unnecessarily, and ultimately to undesired blood damage.

Structures of both the proximal end and other holes of cannulae available in the state of the art are not suitable for directing the blood flow towards the tricuspid valve.

The central venous pressure (CVP) measured from the superior vena cava may be high because of the fact that the cannulae used in the state of the art comprises 4 holes located on 4 sides of a cannula. In particular, an increase in central venous pressure (CVP) may be observed in parallel with an increase in ECMO flow. High CVB may lead to swelling in hands (upper extremity) followed by cerebral edema or an increase in intracranial pressure, thereby leading to brain damage (cerebral deficit). Again, an increased amount of short circuit, namely, a recirculation is inevitable in this design, which in turn, corresponds to an underperforming cannula.

The same design also lacks a fixing element. Therefore, the maintenance of cannula's position is under constant risk. This cannula design further lacks an indicator component that shows the position of the cannula; therefore, a special imaging experience (Echocardiogram/ultrasound) is required in order to ensure that the cannula is positioned properly.

The disadvantages mentioned above limits the use of ECMO in patients who are in need, reduces the benefits gained from ECMO treatment, thereby prolonging the duration of hospital stay or the duration of disease, increasing patient mortality, and consequently, causes increase in health care costs.

Considering both the state of the art and the clinical experiences of attending physicians working in this field, it is observed that there is a need for a novel ECMO cannula that is capable of overcoming disadvantages present in the state of the art, such as recirculation, infection, and difficulty in positioning cannulae.

BRIEF DESCRIPTION OF THE INVENTION

The present invention, with the aim of overcoming the disadvantages disclosed above and introducing further advantages into the relevant technical field, relates to a single lumen venovenous ECMO cannula (A).

The single lumen venovenous ECMO cannula (A) according to the present invention comprises; a horizontally beveled inflow proximal orifice (101), at least one inflow flowdiverting hole (102), a midline (103), a serrated section (104), single lumen cannula body (105), and an internal-external line (106).

In the cannula according to the present invention, the fact that the proximal orifice (101) has a horizontally beveled shape and that the body (105) comprises a plurality of diverting holes thereon reduce the blood trauma induced by the use of an ECMO cannula, thereby broadening the range of application of the cannula. Moreover, since the blood flow is diverted to the tricuspid valve by means of the cannula according to the present invention, the incidence of recirculation (short circuit) present in ECMO cannulae available in the state of the art is reduced or eliminated completely.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 illustrates the front view of the single lumen venovenous ECMO cannula (A) according to the present invention.

Figure 2 illustrates the side view of the single lumen venovenous ECMO cannula (A) according to the present invention.

Reference numerals used in figures and corresponding components are given in the list below:

101 : Horizontally beveled inflow proximal orifice

102: In-flow flow-diverting hole

103: Midline

104: Micro- serrated or reverse dowel section

105: Single lumen cannula body

106: Internal-external line

107: Adjustable clamp

A: Single lumen venovenous ECMO cannula

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a single lumen venovenous ECMO cannula (A) comprising; a horizontally beveled inflow proximal orifice (101), at least one inflow flowdiverting hole (102), a midline (103), a serrated section (104), a single lumen cannula body (105), and an internal-external line (106).

The ECMO cannula according to the present invention comprises 1-5 inflow flowdiverting holes (102).

In a preferred embodiment of the present invention, the proximal end (101) of the cannula (A) according to the present invention is provided with a radio-opaque marker.

Body (105) of the cannula according to the present invention may have an elliptical/circular shape. The infusion canal of the body (105) of the cannula according to the present invention is not flexible. Thus, it is ensured that the lumen diameter does not vary depending on the drawing-infusion force in the cannula (A), thereby providing a stable flow. The cannula according to the present invention is further provided with a reverse dowel/micro-serrated element (104), which is a special component providing resistance against potential infections. The cannula according to the present invention comprises a marker (106) that indicates the intracardiac and intravenous position of the cannula. This marker indicates both the level of the cannula and the direction of the orifice transfusing the blood.

The cannula (A) according to the present invention is positioned inside the superior vena cava and employed for returning, i.e., the inflow of cleansed blood to the patient.

The proximal orifice (101) in the cannula (A) according to the present invention is designed to feature an inwardly-beveled shape instead of a flat bevel so as to divert blood to the valve (tricuspid valve).

At the distal portion (upper portion) of the proximal orifice (101) of the cannula (A) according to the present invention is provided 1-5 oval/ellipsoid inflow flow-diverting holes (102) positioned at 1-2 cm intervals such that they are aligned with one another. These holes (102) divert the flow inwards, namely, into the AV valve, that is, to the tricuspid valve, to the right ventricle. A preferred embodiment of the present invention comprises 2-5 inflow flow-diverting holes (102).

In a preferred embodiment of the present invention, the cannula is provided with a midline marker so that the cannula may be positioned properly.

The distal portion of the cannula is further provided with intemal/extemal markers that indicate the inside and outside of the cannula.

While the body (105) of the cannula according to the present invention may be completely reinforced with metal in a spiral pattern (surrounding), this structure may also be available only on certain parts of the cannula, for instance, the percutaneous insertion point of the cannula.

The micro- serrated element (104) included in the ECMO cannula (A) according to the present invention is composed of serrations (104). These serrations (104) are positioned towards the distal end of the body (105) of the cannula. In other words, the serrations provided on the micro- serrated element (104) included in the cannula (A) according to the present invention are positioned on the body (105) of the cannula such that they form an angle in a range between 1° and 175° relative to the body of the cannula. In the micro- serrated element (104), the angle between serrations and the body (105) of the cannula may be, for example; 5 °, 10 °, 15 °, 20 °, 25 °, 30 °, 35 °, 40 °, 45 °, 50 °, 55 °, 60 °, 65 °, 70 °, 75 °, 80 °, 85 °, 90 °, 100 °, 110 °, 120 °, 130 °, 140 °, 150 °, 160 °, 170 °.

The aim of the micro-serrated element (104) provided on the cannula (A) according to the present invention is to create a barrier against percutaneous entry of bacteria and microorganisms.

The cannulae according to the present invention may be manufactured from metallic or polymeric materials available in the state of the art such as chlorine hexidine, potassium iodide, alcohol, etc., that are not affected by disinfectants, that are inert to these disinfectants, and that do not interact with these disinfectants.

The cannula (A) according to the present invention may be manufactured in various types and sizes, and for every age, height, and weight so as to accommodate the characteristics of human anatomy of different sizes, for example, neonatal, pediatric, and adult patients.

The term "comprising" used in the description provided herein is used such that it corresponds to the term "including".

Embodiments of the present invention may be combined where appropriate in the technique.

The embodiments are disclosed herein so as to comprise specific features/elements. Other embodiments that comprise the features/elements described herein, or that are composed of said features/elements are also included in the scope of the description provided herein.

Patent documents and applications, and particularly the patent applications numbered TR 2018/20410, TR 2018/201413, TR 2018/20419, and similar technical references are included in this document through citations.

Embodiments disclosed specifically and explicitly in the description provided herein may solely or in combination with one or more than one embodiments serve as a basis for a disclaimer.