RU2741253C1 - Neocuspidization method of aortic valve - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, particularly to cardiosurgery. Excision of pathological aortic valves is performed. Inter-unit distance IC is determined for each leaf. For each leaf of length L1 of the free edge of the leaf, length L2 of the leaf attachment line to the fibrous ring of the aortic valve and height A of the leaf are calculated. Neovalves is cut out of the flap of autopericardium or xenopericardium in accordance with the calculated values of L1, L2, A with an allowance on seam of 2-3 mm along the line of flap attachment to the fibrous ring, followed by successive fixation of the neovalves with a sutured suture to the fibrous ring of the aortic valve with reconstruction of the coaptation zone geometry. Values L1, L2, A are calculated using original formulas.

EFFECT: method makes it possible to simplify the process of making neovalves, which allow reconstructing the aortic valve by its haemodynamic and morphological characteristics approximating to the native one and not requiring any additional instruments.

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Description

Technology area

The invention relates to medicine, in particular to cardiac surgery and can be used to treat patients suffering from various diseases of the aortic valve.

State of the art

For five decades, aortic valve replacement has been the gold standard in the treatment of aortic valve defects. However, the need for lifelong anticoagulant therapy when using a mechanical prosthesis, the possible complications associated with it and, as a consequence, a deterioration in the quality of life of patients, makes this technique not the best of its kind. Biological valves undergo more rapid degradation and calcification [Surgical treatment of aortic valve disease. Tirone E. David. Cardiol. 10, 375-386 (2013); doi: 10.1038 / nrcardio.2013.72], which requires reoperation, and, despite significant progress in their development and production, the hemodynamic characteristics of bioprostheses are incomparable with native aortic valves. In connection with the above reasons, the technique of reconstruction of the aortic valve from various materials, such as auto-, xenopericadas, and others is being increasingly developed. Today, there are many ways to form the leaflets, which have their pros and cons. Some of them are very subjective and operator-dependent, this can lead to variability in the functioning and duration of the valve [Relationship of Normal Aortic Valve Cusp Dimensions: A Tool to Optimize Cusp Reconstruction Valvuloplasty Sujata Subramanian, MD, Vsevolod Tikhomirov, MD, Saroja Bharati, MD, Chawki ElZein, MD, David Roberson, MD, and Michel N. Ilbawi, MD.].

A special holding device is known for the formation and simultaneous plasty of the aortic valve leaflets [Patent RU2706529 C1. Retaining device for the formation and simultaneous plasty of the aortic valve leaflets. Author: Malkov V.A.]. In the work of Nesmachniy A.S. [Plasty of the aortic valve cusps with a xenopericardial flap using a retaining device as an alternative to aortic valve replacement. Nesmachny A.S., Kareva Yu.E., Ruzmatov T.M., Chernyavsky A.M. "Circulatory pathology and cardiac surgery". 2016; 20 (2): 58-65. DOI: 10.21688-1681-3472-2016-2-58-65] describes in detail the technique of using this device in clinical practice. The positioning of the future leaflets in the holding device prior to implantation allows the formation of a neovalve quickly and accurately, in accordance with the diameter of the aortic annulus. The disadvantage of this technique is the need to use additional tools and, consequently, the associated economic costs.

A known method of forming the aortic valve leaflets, cut out after intraoperative measurement of intercommissural distances [Ivanov VA, Evseev EP, Aydamirov YA, Fedulova SV, Nikityuk TG Aortic valve replacement with xenopericardial leaflets. The journal named after academician B.V. Petrovsky 2016 (4), pp. 16-21]. Based on anatomical studies and calculations by Gasparyan [Gasparyan V.C. Reconstruction of the aortic valve with autologous pericardium: An experimental study. J Thorac. Cardiovasc. Surg. 2000; 117: 386-387] at the Russian Research Center of Art. B.V. Petrovsky developed a template consisting of a holder handle and replaceable nozzles (templates for sash) of different sizes with a cutting edge. Veal xenopericardium was used to make the flaps. The non-leaflets were fixed to the annulus with a continuous 4.0 prolene suture. Experimental and isolated clinical studies have shown good direct results of neovalve operation. However, the need to use additional tools and their lack on the market is a disadvantage of this method.

In 2007 Sh. Ozaki proposed an original technique for the complete restoration of the aortic valve from the autopericardium (prototype). This procedure can be used for a wide range of diseases of the aortic valve, including aortic stenosis, aortic insufficiency, infective endocarditis of both the native valve and the prosthesis, annulo-aortic ectasia [Ozaki S, Kawase I, Yamashita H et al. A total of 404 cases of aortic valve reconstruction with glutaraldehyde-treated autologous pericardium. J Thorac Cardiovasc Surg. 2014; 147 (1): 301-306. doi: 10.1016 / j.jtcvs.2012.11.012]. The original Ozaki method consists in excising the leaflets of the pathological valve, cutting out the non-leaflets from the autopericardium fixed in a 0.6% solution of glutaraldehyde according to specially designed templates and suturing them into the position of the removed leaflets. Today, this valve reconstruction technique is gaining popularity, but the templates and gauges required for it are economical and are made of plastic, which can cause their fragility.

A similar method for the reconstruction of the aortic valve was proposed by J Benedik and called the Benaki procedure [Benedik J. Modification of original Ozaki procedure (Ozaki operation) - Benaki procedure. https://www.youtube.com/watch?v=IUWKSTfKwN4. Published 2020. Accessed June 16, 2020]; [Fehling-instruments.de. Accessed December 3, 2019. Available from: https://www.fehling-instruments.de/wp-content/uploads/2018/09/Kapitel-11-Herz-und-Gefäßchirurgie.pdf]. However, during the operation, sizer-templates made of flexible nitinol material are used, in contrast to rigid Ozaki meters, which makes it possible to simulate templates, giving them the desired shape and it is more convenient to measure the distances between commissures. The disadvantage of this method is also the need to use special equipment for the formation of non-frames.

The technical problem to be solved by the invention is the development of a method for neocuspidization of the aortic valve, which makes it possible to simplify, increase the effectiveness of treatment and reproducibility of surgical intervention for aortic valve defects.

Disclosure of the essence of the invention

The technical result of the invention is to simplify the process of making non-flaps, allowing to recreate the aortic valve, in its hemodynamic and morphological characteristics, close to the native one, and does not require the use of additional tools (templates, denture size rulers, special devices and devices for forming and fixing the flaps, etc.) etc.). The use of the proposed method provides a significant decrease in the average and peak gradients on the aortic valve, the absence of postoperative regurgitation, an increase in the area of the effective opening of the aortic valve, and the absence of the need for lifelong anticoagulant therapy.

The technical result is achieved through the implementation of the method of neocuspidization of the aortic valve, including excision of pathological aortic cusps, determination of the intercommissural distance IC for each cusp, calculation of the length L1 of the free edge of the cusp for each cusp, the length L2 of the line of attachment of the cusp to the fibrous ring of the aortic valve and the height A of the cusp, cutting out flaps from an autopericardial or xenopericardial flap in accordance with the calculated values of L1, L2, A, with a suture allowance of 2-3 mm along the line of attachment of the flap to the annulus, followed by alternate fixation of the flaps with a twisted suture to the fibrous ring of the aortic valve geometry coaptation, while the values of L1, L2, A are calculated by the formulas: L1 = 1.04 * IC + 6.17; L2 = 1.21 * IC + 18.9; A = 0.33 * IC + 10.05.

Brief Description of Drawings

The invention is illustrated by illustrations, where Fig. 1 shows a diagram of a non-flap obtained by calculation formulas (L1 is the length of the free edge of the flap; L2 is the length of the flap attachment line; A is the height of the flap); Fig. 2 shows a diagram of a non-flap adjusted for a seam; Figure 3 shows the stage of surgical intervention on the aortic valve, where the intercommissural distance is measured; figure 4 shows the intraoperative marking of the autopericardium according to the formulas; Fig. 5 shows the moment of fixation of the non-flap to the fibrous ring of the aortic valve; Fig. 6 shows a view of the formed aortic neovalve from the autopericardium according to the formulas.

Implementation of the invention

The normal aortic valve consists of three leaflets, each of which has the following dimensions: the length of the free edge (L1), the length of the leaflet attachment to the annulus fibrosus (L2), and the height of the leaflet (A).

To obtain regression formulas for calculating the size of the flaps, a morphometric study of the normal aortic roots of 54 corpses from the Department of Pathological Anatomy of Sechenov University and GKB im. A.K. Eramishantseva. We measured and analyzed the main dimensional characteristics of the aortic root as a whole (circumference at the level of the ventriculo-aortic junction, Valsalva sinuses and sinus-tubular junction) and each valve separately (intercommissural distance, length of the free edge, length of the line of valve attachment and height of the valve). The main selection criterion was the absence of any pathological changes in the structures of the aortic root. It is important to note that according to the ECHO-KG, performed on patients in the hospital shortly before death, the function of their heart valves did not suffer.

The study included 54 corpses, including 30 (56%) men and 24 (44%) women. Age ranged from 38 to 85 years (mean 65 ± 13.7 years, median 66.0), height - from 150 to 185 cm (mean 167.5 ± 8.79 cm, median 167.0), weight - from 40 up to 120 kg (average 74.2 ± 18 kg, median 70.0), BMI - from 1.37 to 2.26 m ² (average 1.83 ± 0.23 m ² , median 1.8), BMI - from 12.2 to 43.5 kg / m ² (average 25.74 ± 5.68 kg / m ² , median 24.6). The obtained results of morphometry served to form a database, which was subjected to statistical analysis.

All dimensional characteristics of the three valves were compared with each other for intergroup differences using one-way ANOVA and the use of the Kruskal - Walliss N test. The comparison did not reveal statistically significant intergroup differences between the valves. For all valve sizes, the value was p> 0.05 (intercommissural distance p = 0.083, commissure height p = 0.059, free edge length p = 0.331, attachment length p = 0.056, valve height p = 0.518). This made it possible to combine data on non-coronary, right and left coronary valves into one group, increasing the number of observations from 54 to 162 units. A correlation-regression analysis was performed between the dimensional characteristics of the aortic valve leaflets.

To identify significant correlations, the threshold value of the Pearson correlation coefficient r> 0.6 was used. Of greatest interest was the dependence on the indicator, which can be easily measured intraoperatively - intercommissural distance. The correlation coefficients between the intercommissural distance and the length of the free edge of the valve, as well as between the intercommissural distance and the length of the line of attachment of the valve were high and amounted to r = 0.78 and r = 0.71 at p <0.01, respectively. The correlation between the intercommissural distance and the leaflet height was significant, but slightly less high and amounted to r = 0.63 at p <0.01. The construction of regression lines for three dependencies has been completed. In the course of the study, key universal equations were obtained for identifying the sizes of the valves at a known intercommissural distance: L1 = 1.04 * IC + 6.17; L2 = 1.21 * IC + 18.9; A = 0.33 * IC + 10.05, which can be used for neocuspidization.

The proposed method is carried out as follows.

The operation is performed through a median sternotomy using artificial circulation and pharmaco-cold cardioplegia. The aorta is opened 3/4 of its diameter 1 cm above the sinotubular junction. Next, the leaflets of the altered aortic valve are sequentially excised. Then the distance IC between the commissures is determined for the three valves separately, for example, using meters or a ruler. In the absence of the possibility of measuring the intercommissural distance or the need to form new commissures (for example, if there is a bicuspid valve and a desire to make a tricuspid valve), it is sufficient to measure the diameter of the aortic annulus and, based on the formula IC = πd / 3, obtain the average intercommissural distance and, accordingly, calculate the remaining unknowns dimensions of three identical valves.

After determining the distance between the commissures, for each leaf calculate the length L1 of the free edge of the valve, the length L2 of the line of attachment of the valve to the fibrous ring of the aorta and the height A of the valve using the formulas: L1 = 1.04 * IC + 6.17, L2 = 1.21 * IC + 18.9, A = 0 , 33 * IC + 10.05, where IC is the intercommissural distance for each leaflet. Three flaps are cut out from the xenopericardial flap or from the autopericardial flap previously collected from the patient in accordance with the calculated values of L1, L2, A (Fig. 1). As an autopericardial flap, a flap stabilized in 0.6% glutaraldehyde solution can be used [Ozaki S, Kawase I, Yamashita H et al. Aortic valve reconstruction using self-developed aortic valve plasty system in aortic valve disease. Interact Cardiovasc Thorac Surg. 2011; 12 (4): 550-553. doi: 10.1510 / icvts.2010.253682]. Then, departing from the line of attachment of the valve to the fibrous ring by 2-3 mm, draw a dotted line parallel to the line of attachment of the valve - a correction for the seam (Figure 2). Along the dotted lines and along the free edges of the flaps (line L1), 3 new flaps (non-flaps) are cut out. The non-flaps are alternately fixed to the annulus fibrosus with a continuous twisting suture with a monofilament suture prolene 5/0 - 13 from the center of the L2 line to the commissures (ends of the L1 lines) with the reconstruction of the geometry of the coaptation zone. Visual control of the coaptation zone is performed. The threads are brought outside the aorta with the formation of neocomissures, which are then reinforced with Teflon (or pericardium) gaskets and tied in pairs. After fixing all three leaflets and conducting a hydraulic test, the aorta is sutured with a two-row suture, the operation is completed in a standard manner. Transesophageal echocardiography is performed to monitor valve function.

Additionally, at the stage of cutting out the valves, mark the middle of each valve on the line of attachment (midpoint of the L1 line) with a marker, and also mark the centers of the Valsalva sinuses for more accurate alignment and simplification of fixation of the valves to the fibrous ring of the aorta.

The proposed method can be used in the presence of aortic defect for the complete replacement of the aortic valve leaflets. In terms of its hemodynamic characteristics and morphology, the reconstructed valve resembles the native one. The standardization of the technique and its reproducibility will increase the number of reconstructive operations and reduce the need for anticoagulant drugs in the population. Considering the fact that the surgical treatment of aortic defects requires significant economic costs and belongs to the group of the most expensive operations, and the number of adult patients is progressively increasing in all countries of the world, the claimed invention simplifies the manufacture of flaps, since the process does not require additional support, instrumentation and size ruler prostheses, which is beneficial for a medical organization from an economic point of view.

The proposed method was applied in clinical practice in a pilot study. The valve was reconstructed in 12 patients with aortic valve pathology. The following echocardiographic results were obtained: peak velocity at the neovalve was 219 (205; 264) cm / s; peak gradient - 20 (17; 29) mm Hg; average gradient - 11 (10; 14) mm Hg; S holes - 2.1 (2; 2.4) cm2; regurgitation - up to a maximum of 1 degree.

Clinical example

Patient L., 70 years old, was admitted to the cardiac surgery department of the Medical Clinical Hospital No. 1 of the First Moscow State Medical University named after I.I. THEM. Sechenov and was operated on according to the claimed method.

The patient was admitted with a diagnosis of Sclero-degenerative heart disease: severe aortic stenosis, grade 2-3 calcification.

According to echocardiography, global and local LV contractility are not reduced. The leaflets of the aortic valve are degeneratively changed, calcification is 2-3 st, blood flow velocity 453 cm / sec., The maximum gradient on the aortic valve is 82 mm Hg, the average gradient is 55 mm Hg, S of the aortic valve opening is 0.59 cm ² , aortic insufficiency up to 1 degree.

The heart was accessed through a median sternotomy. Then, a pericardial flap with a size of at least 7 x 8 cm was taken, this flap was cleaned from fat and other excess tissues, and the autopericardium was fixed in a 0.6% buffered glutaraldehyde solution for 10 minutes. The treated pericardium was washed 3 times with saline for 6 minutes. The heart-lung machine was connected in a standard manner according to the "right atrium - ascending aorta" scheme, drainage of the left ventricle through the right superior pulmonary vein. Protection of the myocardium during aortic clamping was carried out by the method of pharmaco-cold cardioplegia using Custodiol solution. Cardioplegic solution was delivered antegrade selectively to the orifices of the coronary arteries. Further, the leaflets of the altered aortic valve were sequentially excised. Then the distance between the commissures was determined for the three valves separately (Fig. 3). The values of the intercommissural distance were substituted into the formulas for calculating the length of the free edge of the leaflet, the length of the leaflet attachment to the annulus fibrosus, and the leaflet height. According to the data obtained, 3 new valves were cut out from the treated in a 0.6% solution of glutaraldehyde and the washed autopericardial flap (Fig. 4), the middle of each valve on the line of attachment was marked with a marker. We also marked the centers of the Valsalva sinuses. The flaps were alternately fixed to the annulus fibrosus with a continuous twisting suture with a monofilament suture prolene 5/0 - 13 from the center to the commissures with the reconstruction of the geometry of the coaptation zone (Fig. 5). Visual inspection of the coaptation zone was performed. The filaments were brought out to the outside of the aorta with the formation of neocomissures, which were then reinforced with Teflon gaskets and tied in pairs (Fig. 6). After fixation of all three leaflets and a hydraulic test, the aorta was sutured with a two-row suture, the operation was completed in a standard manner. Smooth postoperative course. Echocardiographic data 2 weeks after surgery: the movement of the obturator elements of the aortic valve is not disturbed, the peak blood flow velocity on the valve is 203 cm / sec., The maximum gradient on the aortic valve is 16.5 mm Hg, the average gradient is 9.1 mm Hg. .article, S aortic valve opening 2.05 cm ² , aortic insufficiency up to 1 degree.

Claims (1)

Method of neocuspidization of the aortic valve, including excision of pathological aortic leaflets, determination of the intercommissural distance IC for each leaflet, calculation for each leaflet the length L1 of the free leaf edge, the length L2 of the line of attachment of the leaflet to the fibrous ring of the aortic valve and the leaf height A, cutting out the non-leaflets from the autopericardial flap xenopericardium in accordance with the calculated values of L1, L2, A with a suture allowance of 2-3 mm along the line of attachment of the leaflet to the annulus fibrosus, followed by alternate fixation of the non-leaflets with a twisted suture to the fibrous ring of the aortic valve with the reconstruction of the geometry of the coaptation zone, while the values L1, L2, A are calculated by the formulas: L1 = 1.04⋅IC + 6.17; L2 = 1.21⋅IC + 18.9; A = 0.33⋅IC + 10.05.

Images