RU2108119C1 - Device for retrograde catheterization of left ventricle in patients with aortic stenosis of high risk degree - Google Patents

Abstract

FIELD: medicine, medicinal equipment. SUBSTANCE: catheter as a flexible tube is designed to have two interdependent, equidimensional, incoherent curvatures situated upon a working edge symmetrically to horizontal plane and where a working opening is available, moreover the radius of curvature arch is one eighth of the diameter of aortic valve ring determined in the course of echocardiographic analysis. At the same time proximal curvature is above symmetry plane, and distal one - under symmetry plane. The presence of equidimensional curvatures enables to increase efficiency of catheter's introduction procedure into left ventricular cavity through a narrowed aortic opening and due to good catheter's controllability is possible to shorten the duration period of roentgen tube that enables to decrease radiation loading upon a patient and medicinal personnel, as well. EFFECT: higher efficiency to be used during operations on endocardial interferences in roentgenosurgical rooms in case of aortic stenosis of different etiology. 2 cl, 1 dwg

Description

 A device for retrograde catheterization of the left ventricle in patients with extreme risk aortic stenosis relates to medicine, namely to the field of operations performed as part of endocardial interventions in an x-ray surgical room for aortic stenosis of various etiologies.

 For the treatment of patients with extreme risk aortic stenosis, the technique of catheter balloon valvuloplasty of the aortic opening is currently used / 1 /. One of the most difficult moments in performing intracardiac manipulations in patients with aortic stenosis with massive calcification is the retrograde conduction of a catheter from the aorta to the left ventricle. This is due both to the absolute reduction in the size of the aortic valve opening, and to the eccentric arrangement and its irregular shape. A decrease in the size of the aortic opening leads to an increase in the speed of the oncoming stream of blood, forcing the float of the working end of the catheter. Attempts to guide the catheter through the narrowed aortic opening in 11-36% of the cases are doomed to failure / 2 /.

 Nevertheless, a number of devices are known by which it is possible to perform retrograde catheterization of the left ventricle.

 So, a catheter with three bends in 2 planes was proposed that fits anatomically into the aorta. Due to the bends, which were selected in accordance with the size of the sinuses, the catheter is firmly installed in the aorta. Its end is oriented perpendicular to the plane of the valve / 3 /.

 However, a large number of bends makes it difficult to insert a catheter into the cavity of the left ventricle. In addition, this device, having a fixation point in the wall of the ascending aortic arch, often found itself in a high-speed blood flow, which caused instability of the catheter and the impossibility of its exact orientation into the aortic opening.

 The closest to the proposed solution for the combination of essential features is a device for retrograde catheterization of the left ventricle, containing an elastic tube made in the form of an arc of a circle at an obtuse angle to the straight section, and the end of the tube is straight and perpendicular to the straight part of the device. This device is known in the literature as the right Amplaz coronary catheter. The absence of sharp bends and the elasticity of the catheter make it easy to conduct it into the cavity of the left ventricle through the narrowed aortic opening / 4 /.

 However, in the presence of specific anatomical conditions of the aortic orifice, the probability of a stable and durable installation is extremely low, since the catheter is constantly in the high-speed blood stream from the left ventricle, undergoing a powerful hydrodynamic shock of the stream.

 Therefore, the aim of the invention is to increase the efficiency of the process of conducting a catheter into the cavity of the left ventricle through a narrowed aortic opening.

 This goal is achieved through the use of a device for retrograde catheterization of the left ventricle, containing an elastic tube made with two mates, oppositely directed bends at the working end, in which, in accordance with the proposed technical solution, the bends are made in the form of two equal semicircles symmetrically relative to the horizontal plane, in which there is a working hole, and the radius of the bending arc is 1/8 of the diameter of the aortic valve ring, about assigned during the preoperative echocardiographic examination of the patient. In this case, the proximal bend is located above the plane of symmetry, and the distal bend is under the plane of symmetry.

 A similar shape of the working end of the catheter and its position in the aorta with a fixation point in the aortic sinus is determined by the desire to exclude the influence of a high-speed blood flow from the left ventricle on it, thereby achieving high stability and the ability to accurately orient the tip of the catheter into the aortic valve opening.

 The drawing shows a device for retrograde catheterization of the left ventricle.

 The device for retrograde catheterization contains an elastic tube 1 made with two conjugate oppositely directed bends 2, 3 at the working end, while the bends 2, 3 are made in the form of equal semicircles located symmetrically relative to the horizontal plane in which the working hole is located, and the proximal bend 2 is located above the plane of symmetry, and the distal bend 3 is under the plane of symmetry.

 The value of the radius of the bending arc is associated with the creation of conditions for minimal resistance to the movement of the conductor in the catheter and the creation of optimal conditions for the search for the aortic opening. The dependence of the value of the radius of the bending arc on the diameter of the aortic valve ring was determined experimentally, and satisfactory results were obtained with a value equal to 1/8 of the diameter of the aortic valve.

 Devices of three sizes R (3 mm, 4 mm, 5 mm) were made, and in each case they are selected individually.

 The retrograde catheterization of the left ventricle in patients with aortic stenosis using the proposed device is as follows.

 Prior to catheter balloon valvuloplasty, the diameter of the aortic ring, the distance from the inner walls of all three aortic sinuses to the center of the aortic opening are determined. A catheter is selected, the size of the working end of which corresponds to the measured parameters as much as possible. Before performing the manipulation of the conductor through the aortic opening, aortography is performed. On the regurgitation stream into the left ventricle, the correctness of the selected size of the working end of the catheter is checked.

 In the future, the device is retrograde inserted into the ascending aorta and proximal knee is installed in the aortic sinus, the width of which corresponds to the selected catheter size as much as possible. Thus, most of the catheter was outside the high-speed blood flow from the left ventricle, thereby preventing its flotation in the ascending aorta. A guidewire is then inserted into the catheter.

 Rotating the catheter in the sinus of the aorta, installing the catheter in adjacent sinuses and changing the angle of inclination of the tip of the catheter when it is shifted towards the aortic arch, they search for the aortic opening.

 Subsequently, after the conductor is inserted into the cavity of the left ventricle, the device is replaced with a well-known catheter. The latter is introduced through the conductor into the cavity of the left ventricle to measure the pressure in it and perform a contrast study.

Example. Patient G., medical history No. 308/40, was admitted to the Nizhny Novgorod Heart Surgery Center on January 26, 94. Based on clinical and instrumental studies, the diagnosis was established: severe aortic stenosis, degree I regurgitation, aortic valve calcification, moderate mitral stenosis, circulatory failure IIB , IV functional class. The area of the aortic opening was 0.7 square meters. see, the ejection fraction of the left ventricle was 34%. According to intracardiac research methods, the patient was diagnosed with I degree of pulmonary hypertension, aortic insufficiency of I degree. The peak systolic pressure gradient was 120 mmHg. Art. During aortography, a hole was visualized, which was an oblique channel in the thickness of sharply deformed, thickened and calcined aortic valve cusps at an angle of about 40-50 ^o C to the plane of the aortic ring. Attempts to guide the catheter into the cavity of the left ventricle using a catheter as a guide failed: a constant distal dislocation of the catheter by a high-speed blood stream was observed, making it impossible to accurately orient the tip of the catheter. The continuous operation time of the X-ray tube was 22 minutes. The use of the Amplaz left 1 catheter also did not give a positive result due to the impossible exact orientation of the catheter tip in the oblique direction of the aortic opening. Attempts to conduct the conductor continued for 21 minutes of continuous operation of the x-ray tube. In this case, we used this device of the above design. During the 9 min operation of the x-ray tube, we succeeded in stable orientation of the tip of the catheter in the direction of the aortic opening and subsequent passage into the cavity of the left ventricle. Subsequently, the aortic orifice was dilated with a balloon catheter of the Silina-Sukhov design (St. Petersburg) with a 56% decrease in the peak systolic pressure gradient and a 101% increase in the area of the aortic orifice. A smooth postoperative period with rapid stabilization of the patient's condition was noted.

 Thus, a good catheter controllability, a stable position of the catheter in the aortic sinuses, the possibility of a clear orientation of the catheter tip in the direction of the aortic orifice will allow in some cases to accelerate the catheterization of the left ventricle in patients with extreme risk aortic stenosis, reduce the time of severe manipulation for the patient, reduce radiation burden on the patient and medical staff.

Claims (2)

 1. Device for retrograde catheterization of the left ventricle in patients with extreme risk aortic stenosis, comprising an elastic tube made with two conjugate oppositely directed bends at the working end, characterized in that the bends are made in the form of equal-sized semicircles located symmetrically relative to the horizontal plane, in which is the working hole, and the radius of the bending arc is 1/8 of the diameter of the ring of the aortic valve, determined during echocardiography research.  2. The device according to claim 1, characterized in that the proximal bend is located above the plane of symmetry, and the distal bend is under the plane of symmetry.