Volume reduction mechanism for left ventricle

Abstract

The invention relates to a volume reduction mechanism for a left ventricle. The mechanism comprises a support and a base connected with the support, wherein the support comprises a plurality of support rods, near ends of the support rods gather together to form a gathering bottom end of the support, and remote ends of the support rods are spread adaptively in a direction getting away from the heart tip from the inner wall of the left ventricle; the base comprises a central end part connected with the gathering bottom end and a plurality of spiral branches extending from the central end part to the heart tip, and the plurality of spiral branches are arranged rotationally symmetrically along a central shaft of the base and forms a trumpet shape with an opening facing towards the heart tip as a whole; the support is made of a shape memory material and covered with a film; the base is made of an elastic material and in adaptive fit with the inner wall of the heart tip. The mechanism reduces apparatus displacement and fracture risks, has quite good fatigue strength and reduces the risk of injuries to blood vessels and heart valves.

Description

technical field [0001] The invention relates to the technical field of medical ventricular isolation devices, in particular to a left ventricular volume reduction mechanism. Background technique [0002] In recent years, the prevalence of heart failure has been increasing year by year, becoming a serious public health problem. Patients with clinical symptoms are similar to malignant tumors. [0003] It has many causes, one of the most common causes is acute myocardial infarction. Clinically, especially in patients with anterior wall myocardial infarction and ventricular aneurysm, the curvature and thickness of the left ventricular wall can be altered, resulting in dilation and deformation of the entire heart. Since the aneurysm affects systolic function, paradoxical motion of the aneurysm portion reduces left ventricular ejection. Combined with scar formation after myocardial infarction, changes in the intrinsic properties of the myocardium and marginal tissue increase the...

AI Technical Summary

Problems solved by technology

The defects of this mechanism are: 1. According to the theory of heart torsion motion, in addition to the periodic systolic and diastolic motion in the radial direction (perpendicular to the central axis of the base), the heart will also undergo a circular rotation direction (along the direction of rotation) during contraction and relaxation. The periodic reciprocating torsional movement of the central axis of the base), after the base of the mechanism is released on the apex, it can only resist the periodic systolic and diastolic motions in the radial direction for buffering in the radial direction, but because the petal edges of the base are fixed by The connection is in a closed state and cannot resist the periodic reciprocating torsional movement in the direction of circular rotation, so it cannot produce a buffering effect in the direction of circular rotation, which in turn causes a series of problems, including the displacement of the mechanism due to being driven, the fatigue fracture of the base, the edge of the metal skeleton Anchor breakage has been reported in the clinical follow-up of this product

2. Since the base is petal-shaped as a whole, and the edges of the petals are in a closed state through fixed connections, the overall space occupied when it is installed into the delivery sheath is relatively large, so the delivery sheath is required to have a larger diameter, which increases the mechanism’s time of introduction. 3. After the mechanism is completely released, the blood in the heart will generate periodicity in the axial direction (parallel to the central axis of the base) The impact force impacts the center of the metal skeleton of the mechanism and then transmits it to the center of the base, and the flat base is difficult to disperse the impact force from the center of the base to the entire base, including the edge of the petals, so the base is in the axial direction and The effect of shock absorption is not really produced, which eventually leads to the fatigue fracture of the metal skeleton in the central area where the metal skeleton gathers. At present, relevant reports have been reported in the clinical follow-up of this product

The base of the mechanism still has the same problems as the base of the Parachute left ventricle volume reduction mechanism, namely: 1. According to the theory of heart torsion motion, the heart is in the process of systole and diastole except for the cycle in the radial direction (perpendicular to the central axis of the base) systolic and diastolic movements, and periodic reciprocating torsional movements in the direction of circular rotation (rotating along the central axis of the base). Cushioning in the radial direction, but because the edge of the petals of the base is in a closed state through a fixed connection, it cannot resist the periodic reciprocating torsional movement in the direction of circular rotation, so the buffering effect in the direction of circular rotation cannot be produced, which in turn causes a series of problems. Driven and shifted, the fatigue of the base breaks, and the anchor thorns on the edge of the metal skeleton break; 2. Since the blood in the heart generates periodic impact force in the axial direction (parallel to the central axis of the base), the main body of the impact mechanism is collected by this force. The center is then transmitted to the base. The base is designed with a cross-woven structure of metal wires and other materials. Although it can play a shock-absorbing role in the axial direction, the metal wires will continue to rub against each other under the action of periodic impact forces, which is extremely It is easy to cause fatigue fracture; 3. Furthermore, the woven cage structure base causes the overall length of the mechanism to be too long, which increases the rigidity of the system, which is not convenient for the system to be introduced in the tortuous blood vessel and cardiac access system, and also brings inconvenience to the operation. It is extremely difficult to operate and requires a large space during the intervention, which may increase the risk of trauma to blood vessels and the heart

[0011] To sum up, the existing left ventricular volume reduction mechanism cannot completely solve the problem of fatigue fracture and displacement of the mechanism caused by the torsional movement of the heart

Seriously affect the quality of life of patients after surgery, and even affect the life expectancy, which shows that the safety and effectiveness of institutions need to be improved urgently

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