A method for modeling an external support for a promising pulmonary artery autograft to be attached to a patient's heart.

Abstract

1. A method for modeling an external support for a potential pulmonary artery autograft attached to a patient's heart using an image scanner (8), comprising: acquiring (100) at least one scan of the cardiac vasculature during cardiac systole using the scanner (8); processing (102) each scan using a processing device (2) to construct a model of the potential pulmonary artery autograft; and processing (104) the model of the potential pulmonary artery autograft to generate a model of the external support. A method is provided that includes:

Description

Technical Field

[0001] The present invention relates to a support for a pulmonary autograft, as well as a method for modeling a promising pulmonary autograft and a method for manufacturing a support for a pulmonary autograft.

Background Art

[0002] The Ross procedure was first reported in 1967 by Donald Ross. In the Ross procedure, a healthy pulmonary valve and a portion of the pulmonary trunk are used as an autograft to replace a diseased aortic valve. The Ross procedure can provide long-term survival potential for aortic valve replacements, which leads to improved outcomes in both patient survival and quality of life.

[0003] In the initial description, this procedure was performed using a sub-coronary technique. In the sub-coronary technique, the pulmonary valve, including all three cusps and the valve leaflets, and a portion of the pulmonary artery are transplanted to a sub-coronary position inside the left ventricular outflow tract. However, this is a technically very difficult procedure and has not been widely accepted among cardiac surgeons.

[0004] Although the results of this technique were promising, the Ross procedure did not become widely popular until the late 1980s when surgeons began to initiate the transplantation of pulmonary autografts as a freestanding root replacement (freestanding root replacement Ross procedure), in which the coronary arteries are retransplanted to the autograft. This technique is technically easier to perform than sub-coronary transplantation; however, when using the freestanding root replacement Ross technique, dilation of the pulmonary autograft was frequently observed.Dilation of the pulmonary autograft can cause valve insufficiency and may require reoperation.

[0005] Therefore, if possible, it would be particularly desirable to reduce the need for reoperation (by dilating the pulmonary artery autologous graft).

[0006] As disclosed in “Conservative Operating in the Management of Annular Dilation and Ascending Aortic Aneurysm” (Francis Robicsek and Mano Thubrikar, Ann Thorac Surg 1994;57:1672-4), which explores methods for simply enclosing the aorta to prevent further dilation, the use of supports that conform to the lateral position of the vessel, developed for countermeasures against aortic aneurysms, is known. In our earlier patent application, International Publication No. 2004 / 026178, we disclose a support manufactured to be shaped to have a morphological relationship with the patient's vessel according to a computer-aided design (CAD) model of the vessel, in order to counteract aortic dilation in Marfan syndrome. For example, when modeling a patient's aorta, it was necessary to collect a pair of adjacent two-dimensional image slices of the aorta using a scanner, and then reconstruct a three-dimensional CAD model by stacking these two-dimensional slices one by one. The drawback of this method is that it is difficult to obtain suitable continuous two-dimensional images due to patient movements, such as breathing, within the scanner. Furthermore, patient fatigue due to the time required to acquire an appropriate number of images can be a problem. In addition, MRI scanners are enclosed spaces, which can trigger claustrophobia in patients.

[0007] An earlier application by the present inventors, International Publication No. 2011 / 012894, discloses a support for the ascending aorta used to counteract aortic dilation associated with Marfan syndrome, and a method for morphometric analysis of a patient's blood vessels using an image scanner, comprising: (i) a step of acquiring a radial cross-sectional image of the blood vessel; (ii) a step of acquiring a pseudo-cross-sectional image of the blood vessel; and (iii) a step of processing the images from steps (i) and (ii) to construct a morphometric model of the blood vessel.

[0008] In the context of the present invention, a pulmonary artery autograft is the patient's own pulmonary artery and valve that replaces the pulmonary artery and pulmonary valve at the aortic location, i.e., the ascending aorta and aortic valve. [Overview of the Initiative] [Means for solving the problem]

[0009] According to a first aspect of the present invention, a method is provided for modeling an external support for a promising pulmonary artery autograft to be attached to a patient's heart using an image scanner, the method being: (i) Using a scanner, take a scan of at least one of the cardiovascular systems during cardiac systole; (ii) The step of processing each scan using a processing device to construct a model of a promising pulmonary artery autograft; and (iii) Step of processing a model of a promising pulmonary artery autograft to generate a model of an external support. Includes.

[0010] Therefore, the inventors recognized that a more useful scan of the pulmonary valve can be obtained during systolic scanning, as blood pressure from the right ventricle is highest at this point in the cardiac cycle, and the diameter of the pulmonary valve is largest at this time. Since the pulmonary artery autograft will withstand higher pressure at the aortic valve site, modeling the pulmonary valve at its maximum normal blood pressure ultimately allows the support to safely extend the pulmonary valve to a suitable diameter.

[0011] In one embodiment, the step of using a scanner to acquire a scan of at least one of the cardiovascular systems during cardiac systole may include the step of acquiring a scan of at least one of the pulmonary valve (PV), pulmonary trunk (PT), aortic root and ascending aorta, aortic valve (AV), left ventricular outflow tract (LVOT), and right ventricular outflow tract (RVOT).

[0012] In one embodiment, the method of the present invention comprises the step of using a scanner to acquire at least one scan of the cardiovascular system during cardiac systole, wherein the at least one scan of the cardiovascular system acquired during cardiac systole includes a scan of the pulmonary valve (PV), at least one scan of the pulmonary trunk (PT), at least one scan of the aortic root near the brachiocephalic bifurcation, at least one scan of the left ventricular outflow tract (LVOT), and at least one scan of the right ventricular outflow tract (RVOT).

[0013] When the pulmonary valve used in the Ross procedure is scanned, the valve is neither dilated nor regurgitating. Due to this fact, and the very low blood pressure (BP) present in the pulmonary vascular / circulatory system, identifying the pulmonary sinus on CT scans is extremely difficult (compared to the high-pressure disease / dilated aorta used in the method described in International Publication No. 2011 / 012894).

[0014] In addition, compared to the left ventricular outflow tract (LVOT) used in the method described in International Publication No. 2011 / 012894, the cross-sectional view of the right ventricular outflow tract (RVOT) shows a considerably lower degree of approximation to a circle when using the CAD modeling method described in International Publication No. 2011 / 012894, which causes problems. Consequently, the method disclosed in International Publication No. 2011 / 012894 is unsuitable for modeling scanned RVOTs.

[0015] Therefore, the inventors recognize that when a pulmonary artery autograft is supported using an implant formed by the method disclosed in International Publication No. 2011 / 012894, once released from pressure on the adjacent aortic structure, the pulmonary artery autograft becomes a more symmetrical trilobed planar figure than when it is located at the pulmonary valve site. These implants are likely to be too small, causing surgical problems during implantation, and are also likely to have an anatomically inappropriate shape.

[0016] Therefore, the method of disclosure in International Publication No. 2011 / 012894 is inappropriate for pulmonary artery autologous grafts.

[0017] In one embodiment of the modeling method described above, the step of using a scanner to obtain at least one scan of the cardiovascular system during cardiac systole includes the step of using a scanner to obtain at least one scan of the pulmonary valve during cardiac systole.

[0018] In one embodiment of the modeling method described above, the step of using a scanner to acquire at least one scan of the cardiac vascular system during cardiac systole includes the step of using a scanner to acquire at least one scan of the left ventricular outflow tract (LVOT) during cardiac systole.

[0019] In one embodiment of the modeling method described above, the step of using a scanner to acquire at least one scan of the cardiovascular system during cardiac systole includes the step of using a scanner to acquire at least one scan from the pulmonary trunk (PT) to the branching points to each lung during cardiac systole.

[0020] In one embodiment of the modeling method described above, the step of using a scanner to acquire at least one scan of the cardiovascular system during cardiac systole includes the step of using a scanner to acquire at least one scan of the pulmonary valve, at least one scan of the aortic valve of the left ventricular outflow tract (LVOT), and at least one scan of the pulmonary trunk.

[0021] Suitable scanners for use in the method according to the present invention may be MRI, MRA, X-ray CT, or three-dimensional Doppler echo imaging scanners. Preferably, the scanner used in the method according to the present invention is a CT scanner.

[0022] In one embodiment, the modeling method of the present invention may include the step of using a scanner to acquire at least one scan of the cardiac vascular system during cardiac systole, wherein the at least one scan includes the step of acquiring at least one image selected from radial cross-sectional images and pseudo-cross-sectional images of the cardiac vascular system during cardiac systole, as described above. However, in a preferred embodiment, the method may include the step of generating at least one alignment image in a plane aligned with the vascular system and, in particular, with a promising pulmonary artery autograft. Typically, each of the alignment images may be aligned with the pulmonary valve or the pulmonary artery trunk. This may be a counteraxial cross-sectional alignment image parallel to the plane of the pulmonary valve or perpendicular to the pulmonary artery trunk, and / or a sagittal alignment image perpendicular to the plane of the pulmonary valve or parallel to the pulmonary artery trunk.

[0023] In one embodiment, the step of obtaining at least one scan of the cardiovascular system during cardiac systole may include the step of obtaining at least one scan of the cardiovascular system within a temporal window during systole in the patient's cardiac cycle. Typically, this temporal window may be from a first point in the cardiac cycle to a second point in the cardiac cycle. The first point in the cardiac cycle may be 5%, 10%, or 15% RR (RR is a commonly used criterion for the time relating to the cardiac cycle, representing the ratio of time from one R peak to the next on an electrocardiogram). The second point in the cardiac cycle may be between 20%, 25%, or 30% RR. In a preferred embodiment, the temporal window is 10%RR to 25%RR during systole. Systolic scans within this temporal window provide a better approximation of the pulmonary valve in systemic blood pressure. During diastole, the sinus is virtually absent (essentially a circular valve portion is present), but during systole (especially at 10%–25%RR), the sinus is visually apparent as three distinct valve lobes forming the valve wall. This allows for safer identification of the pulmonary sinus and also provides a better approximation of the pulmonary valve size in the case of a free-standing aorta.

[0024] In one embodiment of the method of the present invention, the step of processing each scan using a processing device to construct a model of a promising pulmonary artery autograft may further include the step of measuring one or more parameters from at least one scan obtained from the cardiovascular system during cardiac systole.

[0025] In one embodiment, the method of the present invention may include steps of using a scanner to obtain at least one scan of the pulmonary valve during the systolic phase of the heart, at least one scan from the pulmonary trunk to the bifurcation to each lung during the systolic phase of the heart, and at least one scan of the left ventricular outflow tract during the systolic phase of the heart, and measuring one or more parameters from at least one scan of the pulmonary trunk, and measuring one or more parameters from at least one scan of the left ventricular outflow tract.

[0026] In one embodiment, the method of the present invention may include the following. (i) A step of using a scanner to obtain at least one scan of the cardiovascular system of the heart in a time window during the systolic phase of the heart, wherein the step of obtaining at least one scan of the cardiovascular system of the heart includes steps of obtaining at least one scan of the pulmonary valve in a time window during the systolic phase of the heart, obtaining at least one scan of the pulmonary trunk, and obtaining at least one scan of the left ventricular outflow tract; And (ii) A step of using a processing device to process each scan to construct a model of a promising pulmonary autograft, wherein the step of processing further includes steps of measuring one or more parameters from at least one scan of the pulmonary valve, measuring one or more parameters from at least one scan of the pulmonary trunk, and measuring one or more parameters from at least one scan of the left ventricular outflow tract.

[0027] The method of the present invention may further include steps of measuring one or more parameters from at least one scan of the cardiovascular system of the heart during the systolic phase of the heart, and constructing a model of a promising pulmonary autograft using the one or more parameters.

[0028] The method according to the present invention may, for example, use at least four parameters measured from at least one scan acquired from the cardiovascular system during a time window in cardiac systole, and these parameters are used to construct a model of a promising pulmonary artery autograft. Preferably, 4 to 35 parameters, more preferably 5 to 30 parameters, and 5 to 25 parameters, or 6 to 30 parameters, or 8 to 25 parameters, or 10 to 25 parameters, etc., are used to construct a model of an external support for a promising pulmonary artery autograft.

[0029] In one embodiment, at least four parameters are measured from at least one scan of the cardiac vascular system to determine a promising pulmonary artery autograft model. As described above, at least one scan of the cardiac vascular system may include at least one scan of the pulmonary valve, at least one scan of the pulmonary trunk, and at least one scan of the left ventricular outflow tract.

[0030] Preferred parameters obtained from the above reference scan may include linear dimensions, circumferential dimensions, radial dimensions, and / or rotation angles.

[0031] In the context of the present invention, the term diameter refers to any polygonal approximation of a circle or an equivalent diameter, i.e., a trilobed section of the sinus of Valsalva or a substantially circular section of the ascending pulmonary artery.

[0032] The proximal end of the pulmonary aorta must be anastomosed to the LVOT (i.e., the proximal end of the pulmonary artery autograft is typically attached to the upper part of the left ventricular outflow tract (LVOT) by suturing). Therefore, a preferred parameter relating to the method of the present invention may be the base diameter of the LVOT measured during systole (as described above). The base diameter can be measured at the aortic-ventricular junction (the anatomical junction between the distal end of the LVOT (farthest from the ventricle) and the proximal end of the aortic root). The base diameter of the LVOT can be measured from at least one scan of the LVOT during cardiac systole (e.g., 10%RR to 25%RR). For example, at least one scan of the LVOT during cardiac systole may include at least one axial transverse alignment image of the LVOT during systole. This ensures that the promising pulmonary artery autograft is properly fitted to the location where it must be attached / anastomostomosed to the LVOT. If the LVOT is less than 28 mm in diameter, it can be expanded by a surgeon to a diameter of 28 mm or less (e.g., the Konno method).

[0033] In one embodiment, further preferred parameters relating to the method of the present invention may include at least one of the diameters of each lobe in the sinus of a promising pulmonary artery autograft, the relative rotational space of the lobes, and the distance from the centerline of the lumen of the promising pulmonary artery autograft to the center of the lobe circle. These parameters of the pulmonary valve can be measured from at least one scan of the pulmonary valve during cardiac systole (e.g., 10%RR to 25%RR). These parameters are intended to determine the shape of the cross-section of the trilobed surface of the pulmonary valve.

[0034] In one embodiment, a further preferred parameter may be the peripheral length of the pulmonary valve.

[0035] In one embodiment, a further preferred parameter may be the diameter of the ascending sinus-aortic junction (STJ). The STJ diameter can be measured from at least one scan of the pulmonary valve during cardiac systole (e.g., 10%RR to 25%RR). The STJ is located in the upper part of the pulmonary valve where the trilobe portion (the three sinuses of the valve) transitions into a tubular shape (the pulmonary trunk).

[0036] In one embodiment, a further preferred parameter measured from the above reference scan of the vascular system of the systolic heart may be the aortic diameter. The aortic diameter may be measured distal to the aortic valve and from at least one scan of the aorta, typically around the site where a promising pulmonary artery autograft will anastomose to the ascending aorta. The scan may be performed during cardiac systole (e.g., 10%RR to 25%RR). In one embodiment, the distal "aortic" diameter is fixed at 30 mm or 32 mm if the ascending aortic measurement is 32 mm or larger.

[0037] Further parameters may include the height of the pulmonary valve from the plane of the pulmonary-ventricular junction (PVJ) to the plane of the ascending sinus-aortic junction.

[0038] One or more of the above parameters enable the construction of a promising pulmonary artery autologous graft model. This model is particularly useful in freestanding Ross procedures. In one embodiment, this model may be a three-dimensional computer-generated model of a promising pulmonary artery autologous graft.

[0039] In one embodiment, the method according to the present invention as described herein may further comprise a processing device that runs computer-aided design (CAD) software to construct a model of a promising pulmonary artery autograft.

[0040] To generate a model of the external support, this method can incorporate a model of a promising pulmonary artery autograft and apply at least one transformation.

[0041] In one embodiment, at least one transformation may include a shape transformation that includes a step of equalizing the diameters of the leaflets. Typically, the diameters of two smaller leaflets can be enlarged to the diameter of the largest leaflet, but instead, all three leaflets can be adjusted to the average (typically mean or median) leaflet diameter. This results in a better fit of the support to the promising pulmonary artery autograft, given that once the promising pulmonary artery autograft is implanted, it will no longer be compressed by the adjacent aorta and will be subject to higher blood pressure than when it was in its original position.

[0042] Therefore, the shape transformation may act to change the center of the valve leaf from an isosceles triangle to an equilateral triangle. The shape transformation may preserve the peripheral length of the pulmonary valve.

[0043] At least one transformation may include a scaling transformation. Typically, in aortic CAD models, the diameter has traditionally been scaled only to 100%, 95%, or 90% or less of the measured vessel size, depending on the degree of dilation and how much diameter reduction the surgeon deems appropriate. However, in this method, the scaling transformation may include an enlargement of the model size. Typically, the scaling transformation may enlarge the size of the external support model by a certain factor compared to the model of the promising pulmonary artery autograft. This factor can be 1 to 1.25, typically 1.05 to 1.15. This makes it possible to size the (highly elastic) pulmonary artery autograft to the size that the surgeon implanting the pulmonary artery autograft determines to be optimal at the aortic location.

[0044] Next, using a model of the support (e.g., in the form of a CAD model), it is possible to manufacture a mold capable of forming a support for a pulmonary artery autograft. The mold is the physical model of the pulmonary artery autograft. Depending on the manufacturing method employed, the mold can be formed as follows: The CAD model file can be transferred to a suitable rapid prototyping device, such as selective laser sintering (SLS), to manufacture a physical mold from a polymer such as nylon. Other manufacturing techniques such as stereolithography (SLA) and CNC machining can also be used. Of these methods, SLS is advantageous because the polymers commonly used can withstand heating during the sterilization process (here, heating to 134°C for 26 minutes) or during the thermosetting process.

[0045] Next, the mold formed by the above method can be used in one of several manufacturing processes to form a finished support. In one method of manufacturing a finished support, a blank curable support is placed in the mold so as to deform to conform to a shape morphologically corresponding to the shape of the mold.

[0046] In a second embodiment, the present invention relates to a method for manufacturing a support for a pulmonary artery autograft: (i) A method for modeling a support according to a first aspect of the present invention; (ii) Step of constructing a mold from a model of the support; (iii) Step of applying a blank support to a mold This provides a method that includes this.

[0047] Optionally, this method may include a step of curing the shape of the support to match the shape of the mold.

[0048] In one embodiment, the method further includes the step of curing a blank support to form a support having a morphological relationship to a promising pulmonary artery autograft.

[0049] In some embodiments, the step of constructing the mold further includes stretching the blank support over the entire area of ​​the mold where a first additional support area is required. In some embodiments, step (iii) of the method for manufacturing a support for a pulmonary artery autograft according to the present invention further includes curing the stretched area of ​​the blank support and shrink-fitting the other areas of the blank support.

[0050] In a third aspect of the present invention, the present invention provides a support that fits the lateral position of a pulmonary artery autograft, the support being shaped such that it can be positioned around the pulmonary artery autograft when placed in the aortic position and has a morphological relationship with the pulmonary artery autograft, and the support is manufactured according to a second aspect of the present invention.

[0051] In one embodiment, the support is a single mesh that can be formed in a tube. The support may also have two longitudinal edges.

[0052] In a fourth embodiment, a method for supporting a pulmonary artery autologous graft: (i) The step of applying a patient's pulmonary artery autograft to a support according to a third aspect of the present invention. Further methods including this are provided.

[0053] In one embodiment, the support has two longitudinal edges; and the method includes the step of connecting the longitudinal edges so that the support forms a tube surrounding a pulmonary artery autograft.

[0054] Herein, as merely an example, a description of an embodiment of the present invention is given below with reference to the attached drawings. [Brief explanation of the drawing]

[0055] [Figure 1] Figure 1 shows a schematic diagram of an apparatus used in an embodiment of the present invention. [Figure 2]Figure 2 shows a flowchart that sets out the steps to be performed in the embodiment of Figure 1. [Figure 3] Figure 3 shows a cross-section of a human heart. [Modes for carrying out the invention]

[0056] An apparatus used in an embodiment of the present invention is shown in Figure 1 of the accompanying drawings. In this embodiment, the processing computer 1 is capable of receiving a patient scan from a scanner 8 (typically a standard medical computed tomography (CT) scanner), processing the scan, and then controlling the three-dimensional manufacturing apparatus 9.

[0057] The processing computer 1 comprises a processing unit 2 connected to a storage device 4 (e.g., a hard disk) and memory 5 (e.g., random access memory (RAM)). An input / output circuit 3 (such as a network card or other interface) connects the computer 1 to its control unit (monitor 7 and keyboard and mouse 6), as well as to the scanner 8 and 3D manufacturing apparatus 9. The computer 1 may run any convenient operating system such as Windows®, Apple MacOS®, or Linux®. The computer 1 will be provided with software suitable for processing scans from the scanner 8 and controlling the 3D manufacturing apparatus 9, as will be described later with reference to the flowchart in Figure 2 of the attached drawings. The following discussion is based on the assumption that the processing is performed by a single computer, but there is no disagreement that the tasks can be distributed in any convenient manner involving different computers.

[0058] In step 100, the patient is first scanned using scanner 8. Ideally, to prevent recording errors, a scan image including the pulmonary valve (PV) 200 (see Figure 3 in the attached diagram) and the surrounding area is acquired as a single scan. The scan is performed at 10%–25% RR (i.e., 10%–25% of the time from one R peak to the next on the patient's electrocardiogram) when the heart is in systole. The results of the scan are a series of two-dimensional slices of the patient's body that, when stacked, form a three-dimensional scan of the patient (or at least their heart).

[0059] Next, computer 1 converts the three-dimensional scan based on the scanner axis into an image referenced to the pulmonary valve 200. This results in at least one image in the cross-sectional plane 201 of the pulmonary valve and one image in the sagittal plane 202 perpendicular to it.

[0060] From these images, in step 102, computer 1 can determine a number of parameters to form a model of the pulmonary valve (PV) 200 for creating a promising pulmonary artery autograft. These parameters include: • Diameter of PV200 • Diameter of the left ventricular outflow tract (LVOT) 203 • Diameter of the ascending aorta (205 mm) • PV axial height (i.e., distance along plane 202 from the plane of the pulmonary ventricular junction (PVJ) to the plane of the ascending aortic junction of the pulmonary sinus) • Diameter of the ascending aortic junction with the PV sinus • The diameter of each of the three lobes of the PV • Relative angle of PV lobes centered on the lumen • Distance from the center of the lumen to the center of the circle defined by each of the PV lobes • Circumference of the PV around the petal leaf • The height of the upright tube (i.e., how much of the PV along pulmonary artery 204 will be implanted) • The taper of the upright tubular section (i.e., the degree to which the support is tapered for the transition from the PV to the aorta 205).

[0061] When diameters are measured, they are based on approximations of a circle, polygonal approximations of a circle, or equivalent diameters, i.e., trilobed sections of the sinuses of Valsalva or substantially circular sections of the ascending pulmonary artery.

[0062] In step 104, to generate a model for an external support for a pulmonary artery autograft, computer 1 takes in a model of a promising pulmonary artery autograft and applies a transformation.

[0063] The first transformation is a shape transformation that equalizes the diameters of the PV sinus lobes. Typically, the diameters of the two smaller lobes can be enlarged to the diameter of the largest lobe, but instead, it is possible to adjust all three lobes to the mean (typically mean or median) lobe diameter. This results in a better fit of the support to the promising pulmonary artery autograft, keeping in mind that once implanted, it will no longer be compressed by the adjacent aorta and will receive higher blood pressure than when it was in its original position.

[0064] Therefore, the shape transformation changes the center of the valve leaf from an isosceles triangle to an equilateral triangle. The shape transformation may preserve the peripheral length of the pulmonary valve.

[0065] The next transformation is scaling transformation. Typically, in conventional aortic CAD models, the diameter was scaled only to 100%, 95%, or 90% or less of the measured vessel size, depending on the degree of dilation and how much diameter reduction the surgeon considered appropriate. However, in this method, scaling transformation typically enlarges the model size to 105% to 115% of the original model. This makes it possible to set the (highly elastic) pulmonary artery autologous graft to the size deemed optimal for the aortic position by the surgeon who implants the pulmonary artery autologous graft.

[0066] In step 106, a mold can then be manufactured using a model of the support (e.g., in the form of a CAD model) that can form a support for the pulmonary artery autograft. This mold is the physical model of the pulmonary artery autograft. Depending on the manufacturing method employed, the mold can be formed as follows: The CAD model file can be transferred to a suitable rapid prototyping device, such as a 3D manufacturing apparatus 9, which may include a selective laser sintering (SLS) machine. The 3D manufacturing apparatus forms the physical mold using a polymer, such as nylon. Other manufacturing techniques, such as stereolithography (SLA) or CNC machining, can also be used. Of these methods, SLS may be advantageous because the polymers commonly used can withstand heating during the sterilization process (here, heating to 134°C for 26 minutes) or during the thermosetting process.

[0067] In step 108, it is then possible to form a finished support using the mold in a number of manufacturing processes. In this embodiment, a blank curable support is laid in the mold so as to deform to conform to a shape morphologically corresponding to the shape of the mold. The support is then subjected to a curing treatment so as to maintain the morphological shape of the mold, and can be, for example, thermocured.

[0068] It is possible to extend a blank support over the entire region of the type where a first additional support area is required. This support can typically be formed into a tube, but before implantation it is a single mesh with two longitudinal edges.

[0069] In step 110, the PV200 is implanted to replace the damaged aortic valve 206. The support is wrapped around the pulmonary artery autograft to be implanted, and the longitudinal edges are sealed together (e.g., by suturing).

Claims

1. A method for modeling an external support for a promising pulmonary artery autograft to be attached to a patient's heart using an image scanner, the following: (i) Using the scanner, take a scan of at least one of the vascular systems of the heart during the systolic phase of the heart; (ii) The step of processing each scan using a processing device to construct a model of the promising pulmonary artery autograft; and (iii) The step of processing the model of the promising pulmonary artery autograft to generate a model of the external support. A method that includes this.

2. The method according to claim 1, wherein the step of using the scanner to obtain a scan of at least one of the vascular systems of the heart during systole includes obtaining a scan of at least one of the pulmonary valve (PV), pulmonary trunk (PT), aortic root and ascending aorta, aortic valve (AV), left ventricular outflow tract (LVOT), and right ventricular outflow tract (RVOT).

3. The method according to claim 2, comprising the step of generating at least one alignment image on a plane aligned with the vascular system.

4. The surface is aligned with the promising pulmonary artery autograft, The method according to claim 3.

5. The method according to claim 3, wherein each of the alignment images is aligned with the pulmonary valve or the pulmonary trunk.

6. The method according to claim 5, wherein the alignment image includes a trans-axial alignment image parallel to the surface of the pulmonary valve or perpendicular to the pulmonary trunk, and / or a sagittal alignment image perpendicular to the surface of the pulmonary valve or parallel to the pulmonary trunk.

7. The method according to any one of claims 1 to 6, wherein the step of obtaining at least one scan of the cardiovascular system during the systole of the heart includes the step of obtaining at least one scan of the cardiovascular system within a time window during the systole of the patient's cardiac cycle.

8. The time window is 10%R-R to 25%R-R. The method according to claim 7.

9. The method according to any one of claims 1 to 8, wherein the step of processing each scan using a processing device to construct a model of the promising pulmonary artery autograft includes the step of measuring one or more parameters from the at least one scan obtained from the cardiovascular system during cardiac systole.

10. The aforementioned parameters are: a) The base diameter of the left ventricular outflow tract (LVOT) of the heart, typically measured at the aortic-ventricular junction. b) The diameter of each lobe in the sinus of the promising pulmonary artery autograft, the relative rotational space of the lobes, and the distance from the centerline of the lumen of the promising pulmonary artery autograft to the center of the circle of the lobe. c) Peripheral length of the pulmonary valve of the heart d) Diameter of the ascending aortic junction (STJ) e) Aortic diameter f) The height of the pulmonary valve from the surface of the pulmonary ventricular junction (PVJ) to the surface of the ascending aortic junction of the pulmonary sinus. The method according to claim 9, comprising at least one of the following.

11. The method according to any one of claims 1 to 10, wherein the (iii) step of processing the model of the promising pulmonary artery autograft to generate a model of the external support is to incorporate the model of the promising pulmonary artery autograft and apply at least one transformation.

12. The method according to claim 11, which is dependent on item b of claim 10, wherein the at least one transformation includes a shape transformation that includes the step of making the diameters of the petals equal.

13. The method according to claim 12, wherein the shape transformation acts to transform the center of the petal leaf from an isosceles triangle to an equilateral triangle.

14. The method according to claim 12 or claim 13, wherein the shape transformation maintains the peripheral length of the pulmonary valve of the heart.

15. The method according to any one of claims 11 to 14, wherein the at least one transformation includes a scaling transformation.

16. The method according to claim 15, wherein the scaling transformation enlarges the size of the model of the external support compared to the model of the promising pulmonary artery autograft.

17. The method according to claim 16, wherein the scaling transformation enlarges the size of the model of the external support by a factor of 1 to 1.

2.

18. The method according to any one of claims 1 to 17, comprising the step of manufacturing a mold capable of forming the support for a pulmonary artery autograft using the model of the support.

19. The method according to claim 18, comprising the step of forming the support using the mold.

20. The method according to claim 19, wherein a blank curable support is laid in the mold in order to form the support.

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