WO2021031616A1

WO2021031616A1 - Triple micro-catheter device and method for transthoracic and epicardial intramyocardial injection under ultrasound guidance

Info

Publication number: WO2021031616A1
Application number: PCT/CN2020/088743
Authority: WO
Inventors: 曹丰; 陶博; 刘峻松; 李苏雷; 邱雅
Original assignee: 中国人民解放军总医院; 曹丰
Priority date: 2019-08-20
Filing date: 2020-05-06
Publication date: 2021-02-25
Also published as: CN110339434A

Abstract

A triple micro-catheter device, for transthoracic and epicardial intramyocardial injection under ultrasound guidance. The triple micro-catheter device comprises: a thick puncture needle (10), a micro-catheter (20), and a thin needle core (30). In a puncture process, the thin needle core (30) is inserted into the micro-catheter (20), and air tightness is formed between the thin needle core (30) and the micro-catheter (20); when a medicine is injected, the thin needle core (30) is withdrawn from the micro-catheter (20), and a second end of the micro-catheter (20) is connected to a medicine injection device. According to the device and the method thereof, two to three holes only need to be punctured in the chest wall of an experimental animal or a subject each time, the medicine can be injected into the myocardium via the thoracic epicardium by means of the micro-catheter (20) under the ultrasonic guidance, and the influence of heart beat on puncture needle positioning can be overcome; accurate administration is achieved, secondary myocardial injury is avoided, and the advantages of being high in local administration concentration, accurate and controllable in injection position, small in trauma, few in complications, capable of achieving administration for many times at different time points and the like are achieved. A convenient, safe and efficient intramyocardial administration mode is provided, and a high clinical translational value is achieved.

Description

A triple microcatheter device and method for transthoracic transepicardial intramyocardial injection under ultrasound guidance

Technical field

This application relates to the technology of intramyocardial injection of drugs, in particular to a triple microcatheter device and method for transthoracic transepicardial intramyocardial injection under ultrasound guidance.

Background technique

Cardiovascular diseases account for about 25% of all human deaths. Various cardiovascular diseases can cause heart failure, such as myocardial infarction, valvular disease, cardiomyopathy, hypertension, etc. The incidence of adult heart failure is 1-2% in European and American countries, and 0.9-1.3% in my country, showing an upward trend. For patients with heart failure, even if the primary cause is corrected, most of the cardiomyocytes are in a terminally differentiated state, and the cells lack self-regeneration ability. Once necrosis, it is difficult to regenerate. Therefore, the deterioration of heart function is difficult to reverse, and the mortality rate is high. Constantly consume medical resources. At present, in addition to drug therapy to improve left ventricular remodeling, treatment methods for heart failure also include cardiac resynchronization therapy, left ventricular assist devices, heart transplantation, etc., but all have their own limitations. At present, the long-term prognosis of patients with heart failure is not optimistic. The 5-year survival rate after the first onset of heart failure is less than 50%, which is equivalent to that of malignant tumors.

In recent years, biological treatments represented by stem cells and cytokines have brought hope to patients with heart failure. This treatment has the potential to directly repair damaged myocardium and has great social application value. In scientific research-related animal experiments and clinical experiments, there are currently mainly routes of administration via peripheral veins, via coronary arteries, via catheters via endocardium and via thoracotomy via epicardial intramyocardial injection. Among them, the drugs enter the local myocardium through the blood circulation through the peripheral veins and coronary arteries, making the local blood drug concentration of the damaged myocardium low and the effect is poor. Transendocardial drug delivery through a catheter requires special surgical equipment, which is expensive, and the catheter puncture needle is difficult to accurately locate in a three-dimensional heart cavity. The electrophysiological system mapping further increases the difficulty and cost of the operation, which affects practical applications. However, the injection route of thoracotomy via epicardial intramyocardial injection, although the local blood concentration of the damaged myocardium is high, the trauma of thoracotomy is large, the risk of anesthesia is high, the structure of the pericardium is directly destroyed, the postoperative scar adhesion further reduces the intervention effect, and clinical application is difficult , More used for patients who originally planned thoracotomy. Therefore, exploring a way and method that is less traumatic, can accurately locate the local myocardial tissue that needs intervention, and has high drug delivery efficiency has strong scientific research and clinical application value.

The current spatial resolution of high-resolution ultrasound is close to that of magnetic resonance imaging. The high-quality images make the clinical application of ultrasound-guided puncture more and more widely used in many diseases such as liver tumors and thyroid nodules. Since the heart is a continuously beating organ, and ultrasound has the characteristics of high time resolution, ultrasound has unique advantages in the field of cardiac imaging. We have found in previous animal experiments that if thoracotomy or high-resolution ultrasound is used to guide the clinically commonly used bevel puncture needle (18G or 22G) to puncture myocardial tissue, as long as it does not directly damage the blood vessels and penetrate the ventricular wall, only a small amount of local myocardium permeates Blood, animal vital signs are stable.

Coronary arteries and veins are distributed in the epicardium. Once injured during puncture, acute pericardial tamponade may be life-threatening. In addition, the heart continues to beat, which has a great influence on the precise control of the puncture injection and drug delivery position. When the puncture needle is completely fixed, with the heart contraction and relaxation movement, it may cause secondary injury, and the injection drug location will also change. The conventionally used puncture needle is a bevel puncture needle with a matching needle core inside. The needle body shows strong echo under ultrasound. A thick puncture needle, such as an 18G puncture needle with an outer diameter of 1.2mm, is more conducive to penetrating superficial hard tissues, and Establish a stable channel in the surrounding bony tissues such as the chest wall, but the risk of damaging deep tissues, especially important tissues, is higher. For example, when transthoracic epicardial puncture of the myocardium, the risk of damaging the epicardial blood vessels is even greater High, the direct damage to the local myocardial tissue is also greater.

Disclosure of invention

In view of the above-mentioned problems, this application aims to propose a microcatheter device that can perform intramyocardial injection through the thorax and epicardium under ultrasound guidance, which can directly administer and inject the myocardium. This application also aims to propose a method for injecting the myocardium through the thoracic epicardium under ultrasound guidance.

This application proposes a triple microcatheter device for intramyocardial injection through the thorax and epicardium under ultrasound guidance, which includes: a thick puncture needle, a micro catheter, and a fine needle core;

The thick puncture needle is formed into a tube body, the first end of which is a tip with a bevel, which is used to puncture the chest wall;

The microcatheter is a flexible tube body, the first end of which is a tip with a bevel, which is used to penetrate the subject's myocardium;

The thin needle core is formed as a solid, and its first end is a tip with a bevel;

The length of the micro catheter and the fine needle core is greater than the length of the thick puncture needle;

The micro catheter is inserted into the thick puncture needle, and the gap between the micro catheter and the thick puncture needle is airtight;

During the puncture process, the fine needle core is inserted into the microcatheter, and the space between the fine needle core and the microcatheter is airtight; when the drug is injected, the fine needle core is withdrawn from the microcatheter, and the second end of the microcatheter Connect with drug injection device.

Preferably, a marker is formed on the first end of the microcatheter, and the marker has a strong echo under ultrasound.

Preferably, during the puncture process, when puncturing the chest wall, the bevel of the first end of the thick puncture needle, the bevel of the first end of the microcatheter, and the bevel of the first end of the thin needle core are aligned to form a flat bevel.

Preferably, during myocardial puncture, the first end of the micro catheter and the first end of the fine needle core extend from the first end of the thick puncture needle together.

Preferably, the microcatheter includes a plurality of markers distributed along its length, wherein at least one marker is located at the first end of the microcatheter.

Preferably, a scale is formed on the outside of the thick puncture needle; a scale is formed on the outside of the micro catheter.

Preferably, the second end of the thick puncture needle is formed with an end seat; the second end of the micro catheter is formed with an end seat; the second end of the fine needle core is formed with an end seat; the end of the micro catheter A recess is formed on the second side of the seat; a protruding head is formed on the first side of the end seat of the fine needle core; the protruding head is detachably snapped into the recess, so that the micro catheter and the fine needle The core is formed as one body.

This application proposes an ultrasound-guided transthoracic transepicardial intramyocardial injection method, which uses the aforementioned triple microcatheter device for injection;

The fine needle core is inserted into the catheter, and the micro catheter is inserted into the thick puncture needle. When the first ends of the thick puncture needle, micro catheter, and fine needle core are aligned, perform chest wall puncture;

After the chest wall puncture is completed, extend the micro-catheter and the fine needle core together beyond the first end of the thick puncture needle, select an appropriate epicardial puncture point, and puncture the left ventricle to a predetermined depth at a predetermined angle to complete the myocardial puncture;

Remove the fine needle core, connect the second end of the micro catheter to the drug injection device, and deliver the drug to the myocardium through the micro catheter;

After the administration is completed, the microcatheter is first withdrawn into the thick puncture needle. Ultrasound observes that there is no pericardial effusion and the blood circulation is stable. Then together with the thick puncture needle, the chest wall is withdrawn and the skin opening is closed.

Preferably, the depth of the first end of the microcatheter into the myocardium is 1-5 cm;

When the first end of the microcatheter is located in the myocardium in the endocardium and the epicardium, and the distance D1 from the endocardium layer and the distance D2 from the epicardium layer during diastole are both greater than 2mm, the drug is injected.

Preferably, the angle between the line connecting the epicardial puncture point and the short axis centerline of the left ventricle and the inserted microcatheter and the fine needle core is 120°-150°.

The ultrasound-guided transthoracic epicardial intramyocardial injection of the triple microcatheter device and method for ultrasound-guided transthoracic epicardial intramyocardial injection of the present application only needs to be in the chest wall of the experimental animal or subject each time Puncture 2-3 holes (each hole is about 1mm in diameter), and the drug can be injected into the myocardium through the epicardium through the thoracic epicardium through the microcatheter under ultrasound guidance, and it can overcome the influence of heartbeat on the positioning of the puncture needle. Drug administration can avoid secondary damage to the myocardium. It has the advantages of high local drug concentration, precise and controllable injection location, less trauma, fewer complications, and multiple drug administration at different time points. The triple microcatheter device and method can be used for non-thoracic minimally invasive intramyocardial injection and administration in scientific research and clinical practice, providing a convenient, safe and efficient intramyocardial administration method, and has strong clinical transformation value.

Brief description of the drawings

FIG. 1 is a schematic cross-sectional structure diagram of each component of the triple microcatheter device of this application;

Figure 2 is a schematic diagram of the triple microcatheter device of the application during chest wall puncture;

Fig. 3 is a schematic diagram of the triple microcatheter device of the application during myocardial puncture;

Figure 4 is a schematic diagram of the triple microcatheter device of the application during drug injection;

Figure 5 is a schematic diagram of ultrasound-guided transthoracic epicardial injection of drugs into pig myocardium;

Figure 6 is a schematic diagram of ultrasound-guided transthoracic epicardial injection into pig myocardium during and after injection;

Figure 7 is a comparison diagram of ultrasound-guided transthoracic epicardial injection into pig myocardium before and after drug injection;

Figure 8 is an image of the puncture site after the animal operation.

The best way to implement the invention

Hereinafter, the triple microcatheter device and method for transthoracic epicardial intramyocardial injection under ultrasound guidance of the present application will be described in detail with reference to the accompanying drawings.

This application proposes a triple microcatheter device for intramyocardial injection through the thorax and epicardium under ultrasound guidance, which includes a thick puncture needle 10, a microcatheter 20, and a fine needle core 30.

The thick puncture needle 10 is formed as a tube body, and the first end of the thick puncture needle 10 is a tip 11 formed with a bevel for puncturing the chest wall.

The microcatheter 20 is a flexible tube body, the first end of which is a tip 21 formed with a bevel, for piercing into the myocardium of the subject.

The thin needle core 30 is formed as a solid, and its first end is a tip with a bevel, which is used to insert the microcatheter 20 to provide rigidity for the microcatheter 20 during the puncture process.

The length of the micro catheter 20 and the fine needle core 30 is greater than the length of the thick puncture needle 10.

The micro catheter 20 is inserted into the thick puncture needle 10, and the micro catheter 20 and the thick puncture needle 10 are formed to be airtight. For example, the outer surface of the micro catheter 20 is in close contact with the inner surface of the thick puncture needle 10 to achieve air tightness. It can also be achieved by providing a sealing means between the microcatheter 20 and the coarse puncture needle 10, such as a sealing ring or a puncturable sealing film.

A scale may be formed on the surface of the micro catheter 20 to facilitate the determination of the penetration depth of the micro catheter.

A scale is formed on the outer surface of the thick puncture needle 10 to facilitate the determination of the puncture depth of the thick catheter.

During the puncture process, the fine needle core 30 is inserted into the microcatheter 20, and the space between the fine needle core 30 and the microcatheter 20 is formed to be airtight, for example, the outer surface of the fine needle core 30 is tightly connected to the inner surface of the microcatheter 20 The airtightness of contact can also be achieved by providing a sealing means, such as a sealing ring or gasket, between the fine needle core 30 and the micro catheter 20; when the drug is injected, the fine needle core 30 is withdrawn from the micro catheter 20 , The second end of the micro catheter 20 is connected with the drug injection device.

A marker 24 is formed at the first end of the microcatheter 20. The marker 24 has a strong echo under ultrasound, such as a metal marker or other material with strong echo under ultrasound, so that it can be clearly observed in the ultrasound image. To the position of the first end of the microcatheter 20, especially the position of the puncture point of the epimyocardium and the position in the myocardium, to facilitate the judgment of whether the puncture point is appropriate and the injection point is appropriate. The marker may be a plurality of marking points distributed along the microcatheter 20, at least one of which is located near the first end of the microcatheter 20.

During the puncture process, when puncturing the chest wall, the bevel of the first end 11 of the thick puncture needle 10, the bevel of the first end 21 of the microcatheter 20, and the bevel of the first end 31 of the thin needle core 30 are aligned to form a flat bevel. , As shown in Figure 2, it is convenient to puncture the chest wall.

During myocardial puncture, the first end 21 of the micro catheter 20 and the first end 31 of the fine needle core 30 extend from the first end 11 of the thick puncture needle 10 together, as shown in FIG. 3.

The second end of the coarse puncture needle 10 is formed with an end seat 12, which is convenient to hold for corresponding operations on the coarse puncture needle.

The second end of the micro-catheter 20 is formed with an end seat 22, which is convenient to hold and operate the micro-catheter.

The second end of the thin needle core 30 is formed with an end seat 32, which is convenient to hold and operate the thin needle core.

A recess 23 is formed on the second side of the end seat 22 of the micro catheter 20; a convex head is formed on the first side of the end seat 32 of the fine needle core 30; the convex head is detachably snapped into the recess 23 so that the micro The catheter 20 is formed integrally with the thin needle core 30.

This application proposes an ultrasound-guided transthoracic transepicardial intramyocardial injection method, in which the aforementioned triple microcatheter device performs injection.

The specific steps are as follows:

(1) The short-axis view of the left ventricle of the heart is displayed through the ultrasound diagnostic apparatus, and the anterior wall and the anterior wall of the left ventricle are selected as the drug delivery area. The puncture needle is punctured under the condition that ultrasound is completely visible, and the needle is inserted at the upper edge of the next rib. The path avoids the anterior interventricular groove directly opposite the ventricular septum to prevent damage to the anterior descending vessel. Control the puncture needle to avoid the needle parallel to the contraction direction of the myocardium on the short axis, reduce the risk of penetrating the ventricular wall, and the longer intramyocardial needle path is beneficial to increase the drug delivery space.

(2) First, use the puncture frame provided with the ultrasound probe to fix the thick puncture needle, penetrate the micro catheter and the fine needle core, and the three form a whole before puncture. The thick puncture needle carries the micro catheter and the fine needle core to keep the tip level, punctures the chest wall with a sense of breakthrough, and fixes it before puncturing the pericardium and myocardium, as shown in Figure 2.

(3)Using the guide line that comes with ultrasound to determine the position of the needle path for further puncturing the myocardium, and further pushing the micro catheter and fine needle core, because there is no need to exchange steps, avoid and reduce the occurrence of pneumothorax. Premature ventricular beats may occur in ECG monitoring when the fine needle core and micro catheter are just punctured into the myocardium, which can be used as an auxiliary judgment. Use a fine needle core to carry the microcatheter into the myocardium for 1-5cm, use the scale mark on the surface of the microcatheter to determine the depth of the needle, and determine the drug delivery position with the metal mark on the tip of the microcatheter during diastole, which is away from the endocardium and epicardium Keep a safe distance above 2mm, and exit the fine needle core if there is no abnormality observed. The micro-catheter beats with the myocardium, and the tail end can be directly connected to the syringe after the negative pressure is drawn back to avoid secondary damage to the myocardium, as shown in Figure 3 and Figure 4.

(4) The microcatheter is gradually withdrawn, and a single needle track can be intermittently injected at multiple points during the withdrawal. After the administration is completed, the microcatheter is first withdrawn into the thick puncture needle, and the ultrasound observation is that there is no pericardial effusion and the blood circulation is stable, and then the thoracic cavity is withdrawn together, and the skin opening is closed. Under ultrasound guidance, re-select the chest wall needle insertion position and needle path, and the same patient can choose two or more puncture paths for drug delivery.

(5) Routinely observe the ECG and pericardium for 1 hour after myocardial puncture and administration to maintain the stability of the ECG, and place a tube for drainage if necessary to improve safety.

Example

1. Apparatus and equipment preparation, mainly including high-resolution ultrasound diagnostic apparatus, cardiac ultrasound probe, probe puncture frame, triple microcatheter device of this application, and 2ml syringe. Among them, the thick puncture needle, the fine needle core, and the metal mark at the tip of the microcatheter are all strongly echoed under ultrasound to facilitate positioning under ultrasound guidance.

2. After the animal is anesthetized and depilated, take the supine position, adjust the position of the ultrasound probe, select the left ventricle short axis anterior wall and anterior wall as the drug delivery area, and insert the needle at the upper edge of the next rib, avoiding the puncture path directly opposite the ventricular septum Interventricular groove to prevent damage to the anterior descending branch. Control the puncture needle to avoid the needle parallel to the contraction direction of the myocardium on the short axis, reduce the risk of penetrating the ventricular wall, and the longer intramyocardial needle path is beneficial to increase the drug delivery space. Select the injection site under the condition that the needle tip is completely visible on the ultrasound. For myocardial infarction minipigs, the ischemic area above the myocardial infarction segment is selected for precise injection, as shown in Figure 6 and Figure 7.

3. First, use the puncture frame that is matched with the ultrasound probe to fix the thick puncture needle, penetrate the micro catheter and the fine needle core, and the three form a whole before puncture, as shown in Figure 2. The thick puncture needle carries a micro catheter and a fine needle core to keep the tip level, punctures the chest wall, with a sense of breakthrough, and fixes it before puncturing the pericardium and myocardium.

4. Use the guide wire that comes with ultrasound to determine the position of the needle path for further puncturing the myocardium, and further push the microcatheter and fine needle core without exchange, avoiding and reducing the occurrence of pneumothorax. Premature ventricular beats may occur in ECG monitoring when the fine needle core and micro catheter are just punctured into the myocardium, which can be used as an auxiliary judgment. Use a fine needle core to carry the microcatheter into the myocardium for 1-5cm, use the scale mark on the surface of the microcatheter to determine the depth of the needle, and determine the drug delivery position with the metal mark on the tip of the microcatheter during diastole, which is away from the endocardium and epicardium Keep a safe distance above 2mm, and exit the fine needle core if there is no abnormality observed. The microcatheter beats with the myocardium, and the tail end can be directly connected to the syringe for negative pressure retraction to avoid secondary damage to the myocardium, as shown in Figure 3 and Figure 4.

5. Gradually withdraw the microcatheter, a single needle track can be intermittently injected into multiple points during the withdrawal process. After the administration is completed, the microcatheter is first withdrawn into the thick puncture needle, and the ultrasound observation is that there is no pericardial effusion and the blood circulation is stable, and then the thoracic cavity is withdrawn together, and the skin opening is closed. Under ultrasound guidance, re-select the chest wall needle insertion position and needle path, and the same patient can choose two or more puncture paths for drug delivery. After the injection and administration, only a small amount of needles were left in the puncture part, as shown in Figure 8.

6. During the whole puncture operation and 1 hour after the operation, monitor the subject's ECG, blood pressure, and oxygen saturation. When frequent ventricular premature beats are found on the ECG, the puncture will be suspended to observe the heart rhythm dynamically to reduce the occurrence of ventricular fibrillation may. When ventricular fibrillation or hemodynamic instability occurs, stop the puncture and quickly identify the cause. If it is ventricular fibrillation, immediately perform asynchronous electrical defibrillation, if unsuccessful, intravenous injection of lidocaine and electrical defibrillation again until sinus rhythm is restored. If pericardial effusion occurs, the dynamic changes of the effusion are monitored by ultrasound. If the effusion is small and the hemodynamics is stable, continue to observe; if the effusion increases rapidly or the hemodynamics is unstable, the area with the most effusion is identified by ultrasound, and the pericardiocentesis is guided by ultrasound. Drainage was continued after the operation until the effusion was reduced to a small amount and had no effect on hemodynamics.

Industrial applicability

The triple microcatheter device and method used for transthoracic transepicardial intramyocardial injection under ultrasound guidance of the present application have the following advantages:

1. Use a thick puncture needle to guide through the chest wall of hard and surrounding bony structures, and carry a micro catheter along the preset guide wire with a fine needle core to puncture the myocardium, which directly reduces the risk of local myocardial injury and epicardial vascular injury. The microcatheter has low friction in the lumen of the thick puncture needle and is easy to enter and exit. At the same time, the inner diameter of the thick puncture needle is equal to the outer diameter of the microcatheter, which can avoid the occurrence of pneumothorax. The micro-catheter enters the myocardial tissue and exits the fine needle core. The micro-catheter can move with the myocardial tissue to a certain extent, overcome the influence of the heartbeat on the drug delivery system, and reduce the secondary damage of the myocardium. The tail end of the micro-catheter can be directly administered after suction by negative pressure, and the operation is smooth, saving operation time and improving operation safety.

2. No thoracotomy, minimally invasive puncture technology under the guidance of high-resolution ultrasound, the tip of the microcatheter has a metal mark, which can be accurately positioned under ultrasound, the operation is safe and feasible, and the drug delivery is clear.

3. Able to achieve single needle injection at different depths, multiple needle paths at different angles, multiple injections at different time points under minimally invasive conditions, so as to achieve the goal of multiple injections at different segments and different depths in the myocardium , Improve drug delivery efficiency.

4. The heart structure and function can be dynamically observed in real time, complications can be found in the first time, catheterization and drainage are convenient, and safety guarantee is improved.

5. It can be directly applied to scientific research practice, such as large animal myocardial infarction/heart failure model intervention research, and the operation is safe and feasible. In terms of clinical transformation, it is more suitable for the treatment of heart failure patients with high risk of conventional surgery, greatly reducing the risk of surgery, and enabling early intervention of heart failure after myocardial infarction, thereby improving the prognosis, and having good scientific research application value and clinical transformation value.

Claims

A triple microcatheter device used for intramyocardial injection through the thoracic epicardium under ultrasound guidance, which is characterized by comprising: a thick puncture needle, a micro catheter, and a fine needle core;

The thick puncture needle is formed as a tube, the first end of which is a beveled tip for puncturing the chest wall; the microcatheter is a flexible tube, and its first end is a beveled tip for piercing In the examinee’s myocardium;

The thin needle core is formed as a solid, and its first end is a tip with a bevel;

The length of the micro catheter and the fine needle core is greater than the length of the thick puncture needle;

The micro catheter is inserted into the thick puncture needle, the micro catheter and the thick puncture needle are airtight; during the puncture process, the fine needle core is inserted into the micro catheter, and the thin needle core and the micro catheter are airtight. When injecting drugs, the fine needle core is withdrawn from the micro catheter, and the second end of the micro catheter is connected to the drug injection device.
The triple microcatheter device of claim 1, wherein:

The first end of the micro-catheter is formed with a marker, and the marker has a strong echo under ultrasound.
The triple microcatheter device of claim 1, wherein:

During the puncture process, when puncturing the chest wall, the bevel of the first end of the thick puncture needle, the bevel of the first end of the microcatheter, and the bevel of the first end of the thin needle core are aligned to form a flat bevel.
The triple microcatheter device of claim 1, wherein:

During myocardial puncture, the first end of the micro catheter and the first end of the fine needle core extend from the first end of the thick puncture needle together.
The triple microcatheter device of claim 1, wherein:

The microcatheter includes a plurality of markers distributed along its length, wherein at least one marker is located at the first end of the microcatheter.
The triple microcatheter device of claim 1, wherein:

A scale is formed on the outside of the thick puncture needle; a scale is formed on the outside of the micro catheter.
The triple microcatheter device according to claim 6, wherein:

The second end of the thick puncture needle is formed with an end seat; the second end of the micro catheter is formed with an end seat; the second end of the thin needle core is formed with an end seat;

The second side of the end seat of the micro-catheter is formed with a recess; the first side of the end seat of the fine needle core is formed with a convex head; the convex head is detachably snapped into the recess, so that the The micro catheter and the fine needle core are formed as one body.
A method for transthoracic transepicardial intramyocardial injection under ultrasound guidance, which uses the triple microcatheter device of any one of claims 1-7 for injection;

The fine needle core is inserted into the catheter, the micro catheter is inserted into the thick puncture needle, and the chest wall puncture is performed when the first ends of the thick puncture needle, micro catheter, and fine needle core are aligned;

After the chest wall puncture is completed, extend the micro-catheter and the fine needle core together beyond the first end of the thick puncture needle, select an appropriate epicardial puncture point, and puncture the left ventricle to a predetermined depth at a predetermined angle to complete the myocardial puncture;

Remove the fine needle core, connect the second end of the micro catheter to the drug injection device, and deliver the drug to the myocardium through the micro catheter;

After the administration is completed, the microcatheter is first withdrawn into the thick puncture needle. Ultrasound observes that there is no pericardial effusion and the blood circulation is stable. Then together with the thick puncture needle, the chest wall is withdrawn and the skin opening is closed.
The method of claim 8, wherein:

The depth of the first end of the microcatheter into the myocardium is 1-5 cm;

When the first end of the microcatheter is located in the myocardium in the endocardium and the epicardium, and the distance D1 from the endocardium layer and the distance D2 from the epicardium layer during diastole are both greater than 2mm, the drug is injected.
The method of claim 8, wherein:

The angle between the line connecting the epicardial puncture point and the short axis centerline of the left ventricle and the inserted microcatheter and the fine needle core is 120°-150°.