CN113384764B

CN113384764B - Extracorporeal membrane pulmonary oxygenation cannula for transatrial septum

Info

Publication number: CN113384764B
Application number: CN202110628356.XA
Authority: CN
Inventors: 赵光锋; 胡盛寿
Original assignee: Fuwai Hospital of CAMS and PUMC
Current assignee: Fuwai Hospital of CAMS and PUMC
Priority date: 2021-06-04
Filing date: 2021-06-04
Publication date: 2023-02-28
Anticipated expiration: 2041-06-04
Also published as: CN113384764A

Abstract

The invention discloses an extracorporeal membrane pulmonary oxygenation cannula for puncturing atrial septum, which comprises an insertion part, a bending part, a drainage leading-out part and a connecting part which are sequentially connected. The part of the drainage leading-out part close to the bending part is used as a lower vena cava drainage part. The insertion part, the bending part and the inferior vena cava drainage part are provided with openings. The insertion part, the bending part, the drainage guiding-out part and the connecting part comprise an outer layer and an inner layer. Superelastic reinforcing wires are arranged between the outer layer and the inner layer of the insertion part, the bending part and the drainage leading-out part. The outer layer and the inner layer of the insertion part, the bending part, the drainage guide-out part and the connecting part are integrally formed through a liquid plastic-dipping process. The periphery of the openings on the insertion part, the bending part and the inferior vena cava drainage part is provided with a super-elastic strengthening ring. A resettable super-elastic wire is arranged between the outer layer and the inner layer of the bending part. The invention has the advantages of ultra-thin thickness, high mechanical strength, good flexibility, good blood drainage effect, capability of releasing pressure to the left ventricle and the like.

Description

Extracorporeal membrane pulmonary oxygenation cannula for transatrial septum

Technical Field

The invention relates to a medical cannula, in particular to an extracorporeal membrane pulmonary oxygenation (ECMO) cannula for puncturing atrial septum.

Background

The intubation tube is an important apparatus which directly contacts with organs and tissues of a human body through extracorporeal circulation and realizes designed functions at specific positions. The structure and performance of the cannula largely determine the function and efficiency of the overall blood circulation system.

In recent years, with the development of ECMO systems, both VV-ECMO and VA-ECMO, there is an increasing demand for high efficiency and high energy of the cannula. Generally, the cannula is required to have a smaller wall thickness, so that the thinner the wall of the cannula is, the stronger the blood circulation capacity is, the smaller the required driving force for circulation is, and the less damage to blood is possible. However, when the wall of the cannula is thin, the mechanical strength and flexibility of the cannula are reduced, and the mechanical strength and flexibility ensure that the cannula can smoothly enter the complex structure in the heart of a human body. In addition, the inner and outer surfaces of the cannula are in contact with human blood or human tissue, and therefore, the surface of the cannula needs to be made of a material with good biocompatibility. However, no cannula having the above characteristics is available at present.

In addition, VA-ECMO, for example, tends to produce left ventricular dilatation and pulmonary congestion, however, VA-ECMO does not have left ventricular decompression capability by itself, and therefore it is conventional practice to alleviate left ventricular pressure problems with additional treatment such as IABP, impella or direct surgical decompression. However, these treatments all involve treatment complexity and additional adverse effects.

Disclosure of Invention

The invention aims to provide an extracorporeal membrane pulmonary oxygenation cannula for penetrating atrial septum, which has the characteristics of ultra-thinness, high mechanical strength and good flexibility, has good blood drainage effect, can effectively release pressure to the left ventricle, minimizes the wound to a patient in the operation process, and is suitable for popularization.

In order to achieve the purpose, the invention adopts the following technical scheme:

an extracorporeal membrane pulmonary oxygenation cannula for use in transatrial septum comprising: it is including consecutive pipe form insertion portion, flexion, drainage derivation portion and connecting portion, and the part that is close to the flexion in the drainage derivation portion is equipped with the trompil on the lateral wall of insertion portion, flexion and inferior vena cava drainage portion as inferior vena cava drainage portion, wherein: the insertion part, the bending part, the drainage guiding-out part and the connecting part all comprise an outer layer and an inner layer; flat superelastic reinforcing wires are arranged between the outer layer and the inner layer of the insertion part, the bending part and the drainage guide part; the outer layers of the insertion part, the bending part, the drainage guiding-out part and the connecting part are integrally formed through a liquid plastic-dipping process, and the inner layers of the insertion part, the bending part, the drainage guiding-out part and the connecting part are integrally formed through a liquid plastic-dipping process; the insertion part, the bending part and the openings on the inferior vena cava drainage part are provided with a circle of superelastic reinforcing rings along the periphery of the insertion part, the bending part and the openings, and each superelastic reinforcing ring is connected with a superelastic reinforcing wire adjacent to the superelastic reinforcing ring; a resettable superelastic wire is arranged between the outer layer and the inner layer of the bend along the length direction of the bend, and the resettable superelastic wire is not connected with the superelastic reinforcing wire.

The invention has the advantages that:

on one hand, the invention realizes the ultrathin foundation by the liquid plastic dipping process, has high mechanical strength and good flexibility, on the other hand, by the distribution design of the openings, the uniform blood drainage effect is improved, and the effective pressure release is realized on the left ventricle, and on the other hand, by the design of the bending part and the resettable super-elastic wire, the invention ensures that the blood smoothly and slightly enters the left ventricle with little damage, thereby greatly reducing the damage to the patient.

Drawings

Fig. 1 is a schematic structural view of an extracorporeal membrane oxygenation cannula of the invention.

Fig. 2 is a partially enlarged front end schematic view of the extracorporeal membrane oxygenation cannula of fig. 1.

Fig. 3 is a schematic cross-sectional view of the drainage lead-out portion.

Fig. 4 is an enlarged schematic view of a portion a in fig. 2.

Fig. 5 is a schematic diagram illustrating the use of an extracorporeal membrane lung oxygenation cannula of the present invention.

Detailed Description

As shown in fig. 1 to 5, the extracorporeal membrane pulmonary oxygenation cannula 10 for puncturing atrial septum of the present invention includes a circular tubular insertion portion 11, a bending portion 12, a drainage derivation portion 13 and a connection portion 14 which are connected in sequence, a portion of the drainage derivation portion 13 near the bending portion 12 is used as an inferior vena cava drainage portion 16, openings are provided on side walls of the insertion portion 11, the bending portion 12 and the inferior vena cava drainage portion 16, and a portion of the drainage derivation portion 13 excluding the inferior vena cava drainage portion 16 and a side wall of the connection portion 14 are not provided with an opening, wherein: the insertion part 11, the bending part 12, the drainage guide part 13 and the connecting part 14 comprise an outer layer 21 and an inner layer 23, wherein the outer layer 21 is arranged outside the inner layer 23; for the insertion portion 11, the bending portion 12 and the drainage derivation portion 13, a thin flat superelastic wire 22 is arranged between the outer layer 21 and the inner layer 23 (for the sake of clarity, the superelastic wire 22 is not shown on the insertion portion 11 and the inferior vena cava drainage portion 16 shown in fig. 1); the insertion part 11, the bending part 12, the drainage leading-out part 13 and the outer layer 21 of the connecting part 14 are integrally formed through a liquid plastic-dipping process, and similarly, the insertion part 11, the bending part 12, the drainage leading-out part 13 and the inner layer 23 of the connecting part 14 are integrally formed through a liquid plastic-dipping process; the openings of the insertion part 11, the bending part 12 and the inferior vena cava drainage part 16 are provided with a circle of super-elastic reinforcing rings 24 along the periphery of the openings, and each super-elastic reinforcing ring 24 is connected with the super-elastic reinforcing wire 22 adjacent to the super-elastic reinforcing ring 24; a resettable superelastic wire 17 is further disposed between the outer layer 21 and the inner layer 23 of the bend 12 along the length of the bend 12, and the resettable superelastic wire 17 is not connected to the superelastic wire 22.

In the present invention, the outlet of the insertion portion 11 is defined as the front, and the inlet of the connection portion 14 is defined as the rear.

In practical design, the insertion portion 11, the bending portion 12, the drainage guide portion 13 and the connection portion 14 are all in the form of circular catheters, the insertion portion 11 and the drainage guide portion 13 are linear or substantially linear, the bending portion 12 is in the shape of a circular arc, the insertion portion 11 and the drainage guide portion 13 are in smooth transition through the bending portion 12, that is, the insertion portion 11, the drainage guide portion 13 and the connection portion 14 are all straight pipes without bending, and as shown in fig. 2, the bending angle of the bending portion 12 is generally an obtuse angle.

Fig. 3 shows only the sectional structure of the drainage lead-out portion 13, and the sectional structures of the insertion portion 11 and the bent portion 12 are substantially the same as the sectional structure of the drainage lead-out portion 13, and therefore, it should be understood with reference to fig. 3.

As shown in fig. 1, the tube diameters of the insertion portion 11, the bending portion 12 and the drainage guide portion 13 can be designed to be the same, and the tube diameter of the connection portion 14 is larger than that of the drainage guide portion 13, so that good blood circulation performance can be realized by such tube diameter design.

In addition, in practical design, the length of the cannula 10 of the present invention is much longer than that of a common venous cannula, and the lengths of the insertion portion 11, the bending portion 12 and the inferior vena cava drainage portion 16 should be reasonably designed according to practical requirements, such as design according to the heart parameters of a patient, and will not be described in detail herein.

When the blood drainage device is actually designed, the openings are used for blood dispersion drainage, and the shapes, sizes, quantities and arrangement of the openings can be flexibly designed without limitation. Typically, as shown in fig. 2, the openings are designed as circular openings.

In addition, preferably, the

openings

151, 152 and 153 of the insertion portion 11, the bending portion 12 and the inferior vena cava drainage portion 16 are all multiple and evenly distributed, the number of the openings 151 of the insertion portion 11 is greater than the number of the openings 152 of the bending portion 12, the number of the openings 152 of the bending portion 12 is greater than the number of the openings 153 of the inferior vena cava drainage portion 16, in other words, the openings 151 of the insertion portion 11 are arranged most densely, the openings 152 of the bending portion 12 are arranged most loosely, and the openings 153 of the inferior vena cava drainage portion 16 are arranged most loosely, wherein: the cross-sectional area of the opening 151 in the insertion portion 11 is smaller than the cross-sectional areas of the

openings

152, 153 in the bending portion 12 and the inferior vena cava drainage portion 16, and the cross-sectional areas of the opening 152 in the bending portion 12 and the opening 153 in the inferior vena cava drainage portion 16 can be designed to be equal. The design ensures that the blood drainage flow of the three parts of the insertion part 11, the bending part 12 and the inferior vena cava drainage part 16 is reduced in sequence, thereby ensuring good oxygenation circulation effect of the extracorporeal membrane lung.

In practical design, although the shape, size, number and the like of the openings are not limited, it is preferable that the sum of the cross-sectional areas of all the openings of the insertion portion 11, the bending portion 12 and the inferior vena cava drainage portion 16 is much larger than the cross-sectional area of the outlet of the insertion portion 11. Thus, when the outlet of the insertion part 11 is blocked, blood can be uniformly introduced into the cannula 10, so that the phenomenon that the pressure of a certain part is too high due to the accumulation of blood in the left ventricle is avoided.

As shown in fig. 2, the resettable superelastic wire 17 is disposed on the convex side of the bending portion 12, wherein one resettable superelastic wire 17 is provided, or a plurality of resettable superelastic wires 17 are disposed in parallel. Two resettable superelastic wires 17 are typically designed to meet the requirement of elastic resetability.

In the present invention, the superelastic reinforcing wires 22 may be continuously arranged in a spiral shape (three-dimensional) along the length of the insertion tube 10, but other arrangements may be designed without limitation.

In the present invention, the superelastic wire 22, the superelastic ring 24, and the resettable superelastic wire 17 are used to ensure the mechanical strength of the inventive cannula 10, so that the entire force is reliably applied, and the materials may be designed to be the same.

Further, the superelastic wire 22, the superelastic ring 24, and the resettable superelastic wire 17 may be made of a metal material, preferably a superelastic nickel-titanium alloy material.

In actual fabrication, the superelastic reinforcing ring 24 is connected to the superelastic reinforcing wire 22 by electrochemical etching or laser machining.

In the present invention, the outer layer 21 and the inner layer 23 are made of a novel polymer material with high blood compatibility, namely, a silicone/polyurethane composite material, which is available in the field. In practical designs, the outer layer 21 and the inner layer 23 may be translucent or transparent, without limitation.

Before use, the atrial septum 53 of the patient is perforated by a hole puncher, and the hole diameter is designed according to the tube diameter of the insertion tube 10 (i.e. the tube diameter of the insertion portion 11, the bending portion 12 and the drainage leading-out portion 13).

Referring to fig. 5, it will be appreciated that in the operation of using the inventive cannula 10, an introducer (catheter introducer) is inserted into the inventive cannula 10 such that the insertion portion 11, the curved portion 12 and the drainage lead-out portion 13 are entirely linearly (or substantially linearly) advanced from the femoral vein into the inferior vena cava 60. When the insertion tube 10 of the present invention is inserted and the introducer is gradually withdrawn outward while continuing to enter the right ventricle 51, the curved portion 12 gradually returns to the curved shape by the curved structure of the curved portion 12 itself and the shape memory property of the resettable superelastic wire 17, so that the insertion portion 11 can smoothly pass from the right ventricle 51 through the opening in the interatrial septum 53 and into the left ventricle 52. And during this entire insertion procedure, the cannula 10 of the present invention does not place significant stress on the atrial septum 53, thereby avoiding unnecessary damage to the left and

right ventricles

52, 51 of the heart 50 and other body tissues.

When the insertion portion 11 is in place in the left ventricle 52, the introducer is withdrawn entirely, the connection portion 14 is connected to the associated extracorporeal blood diversion apparatus, and blood diversion can then commence (as indicated by the arrows in fig. 5). At this time, most of the insertion part 11 is located in the left ventricle 52, most of the bending part 12 is located in the right ventricle 51, and the inferior vena cava drainage part 16 is located in the inferior vena cava 60, so that blood in the left ventricle 52, the right ventricle 51 and the inferior vena cava 60 is drained out to the extracorporeal circulation system in a certain proportion according to the design of the sizes and the number of the openings on the insertion part 11, the bending part 12 and the inferior vena cava drainage part 16, and the like, thereby effectively avoiding the increase of the left ventricle pressure caused by the accumulation of the blood in the left ventricle 52 and achieving a good extracorporeal membrane pulmonary oxygenation circulation effect.

The invention has the advantages that:

1. compared with the existing single-cavity femoral vein cannula which can only realize the drainage of the femoral vein, the single-cavity femoral vein cannula realizes the simultaneous drainage of blood in the lower femoral vein, the right atrium and the left atrium and the effective pressure release of the left ventricle besides realizing the good extracorporeal membrane pulmonary oxygenation circulation effect, so the single-cavity femoral vein cannula can be called as the left ventricle pressure release femoral vein cannula.

2. In the invention, the curvature of the intubation tube in the process of entering the left ventricle from the inferior femoral vein and the right ventricle is controllable by virtue of the curve design of the curved part and the design of the resettable super-elastic wire, so that the intubation tube can penetrate through the atrial septum under the condition of no torsional force, and particularly, under the assistance of an intubator, after the intubation tube linearly (or approximately linearly) enters the right ventricle from the inferior vena cava, the intubation tube can be gradually curved so as to smoothly penetrate through the opening on the atrial septum from the right ventricle to enter the left ventricle, so that great stress is not generated on the opening on the atrial septum in the process of inserting the heart upwards, the damage to the right ventricle in the process of inserting the heart upwards is avoided, and unnecessary injury to human tissues in the heart is avoided.

3. According to the invention, the insertion part is used for being inserted into the left atrium, and the small diameter and the large density of the holes on the insertion part are uniformly distributed, so that the blood flow in the left atrium can be effectively controlled by controlling the insertion depth of the insertion part into the left atrium, the pressure of the left ventricle can be effectively controlled, and the pressure of the left ventricle can be prevented from rising.

4. The outer layer and the inner layer of the invention adopt organic silicon/polyurethane composite materials, which have high blood compatibility, greatly improve the safety on the basis of ensuring the mechanical strength and the flexibility, and meet the requirement of blood extracorporeal circulation. In addition, the outer layer and the inner layer of the intubation are integrally formed in one step through a liquid plastic dipping process, so that the manufacturing difficulty of the intubation is simplified, and although the liquid plastic dipping process (also called a solution casting process) is a well-known high polymer material forming technology, the liquid plastic dipping process is firstly applied to the manufacturing of the medical intubation.

5. The super-elastic reinforcing wire, the super-elastic reinforcing ring and the resettable super-elastic wire are made of nickel-titanium alloy, the nickel-titanium alloy has super elasticity (10 times of super elasticity compared with stainless steel), relatively low hardness, ultrathin thickness, mechanical strength and stability, super-strong torque resistance, low density, no magnetism, good overall mechanical property and super-deformation resistance, and good blood compatibility.

6. The invention adopts the superelasticity reinforcing ring made of nickel-titanium alloy to strengthen the firmness of the open pore, increases the mechanical strength on the basis of not losing the flexibility and ensures the drainage effect.

The above description is of the preferred embodiment of the present invention and the technical principle applied thereto, and it will be apparent to those skilled in the art that any equivalent changes, simple substitutions and other obvious changes based on the technical solution of the present invention can be made without departing from the spirit and scope of the present invention.

Claims

1. An extracorporeal membrane pulmonary oxygenation cannula for transatrial septum, comprising: it is including consecutive pipe form insertion portion, flexion, drainage derivation portion and connecting portion, and the part that is close to the flexion in the drainage derivation portion is equipped with the trompil on the lateral wall of insertion portion, flexion and inferior vena cava drainage portion as inferior vena cava drainage portion, wherein: the insertion part, the bending part, the drainage guiding-out part and the connecting part all comprise an outer layer and an inner layer; flat superelastic reinforcing wires are arranged between the outer layer and the inner layer of the insertion part, the bending part and the drainage guide part; the outer layers of the insertion part, the bending part, the drainage guiding-out part and the connecting part are integrally formed through a liquid plastic-dipping process, and the inner layers of the insertion part, the bending part, the drainage guiding-out part and the connecting part are integrally formed through a liquid plastic-dipping process; the insertion part, the bending part and the openings on the inferior vena cava drainage part are provided with a circle of superelastic reinforcing rings along the periphery of the insertion part, the bending part and the openings, and each superelastic reinforcing ring is connected with a superelastic reinforcing wire adjacent to the superelastic reinforcing ring; a resettable superelastic wire is arranged between the outer layer and the inner layer of the bending part along the length direction of the bending part, a plurality of resettable superelastic wires are arranged in parallel, the resettable superelastic wires are not connected with a superelastic reinforcing wire, and the resettable superelastic wires are arranged on the convex side of the bending part; by means of the curve structure of the bending part and the shape memory performance of the resettable super-elastic wire, the integrally linear insertion part, the bending part and the drainage leading-out part are gradually drawn out of the tube inserter to realize gradual bending recovery of the bending part, wherein when the external membrane lung oxygenation intubation tube for the atrial septum is operated and used, the tube inserter is inserted into the external membrane lung oxygenation intubation tube for the atrial septum; the number of the openings in the insertion portion, the number of the openings in the bending portion and the number of the openings in the inferior vena cava drainage portion are multiple and evenly distributed, the number of the openings in the insertion portion is larger than the number of the openings in the bending portion, the cross-sectional area of the openings in the insertion portion is smaller than the cross-sectional area of the openings in the bending portion and the inferior vena cava drainage portion, and the sum of the cross-sectional areas of the openings in the insertion portion, the bending portion and the inferior vena cava drainage portion is far larger than the cross-sectional area of an outlet of the insertion portion.

2. The extracorporeal membrane pulmonary oxygenation cannula for transatrial septum of claim 1, wherein:

the super-elastic reinforcing wire, the super-elastic reinforcing ring and the resettable super-elastic wire are made of the same material.

3. An extracorporeal membrane lung oxygenation cannula for transatrial septum according to claim 1 or 2, wherein:

the superelastic reinforcing wire, the superelastic reinforcing ring and the resettable superelastic wire are made of nickel-titanium alloy materials.

4. The extracorporeal membrane lung oxygenation cannula for transatrial septum of claim 3, wherein:

the super-elastic reinforcing ring is connected with the super-elastic reinforcing wire by adopting an electrochemical corrosion method or a laser processing method.

5. An extracorporeal membrane lung oxygenation cannula for transatrial septum according to claim 1 or 2, wherein:

the outer layer and the inner layer are made of organic silicon/polyurethane composite materials.