AU2005200489B2 - External support for restoring competence to venous valves by traction of their intercommissural walls - Google Patents

Abstract

External support for restoring valvular competence to veins, to be implanted about a vein (V), along its length. It includes a posterior and an anterior arcuate frame shell, in 5 an elongated material. The posterior frame shell (1) includes two branches (2, 3) of said elongated material .penetratingly shaped for an easy insertion thereof behind the posterior wall of the vein (V), through two paths prepared by the surgeon. Each frame shell (1, 2) includes a respective traction side including longitudinal rectilinear side traction branch means (5, 5'; 5A, 5'A). The two frame shells (1, 2) are conformed to be 10 juxtaposed to each other about the vein (V) by longitudinal sides thereof. The traction sides are intended to be engaged to the vein (V) by opposite valve intercommissural walls (iw1, iw2) by means of surgical sutures (s1, s2) or hook means to dilate the intercommissural diameter of the vein by traction, so as to absorb the slackening of an incompetent venous valve by extending its cusps (c1, c2). 2AP 2A? 2' 2' 3cl 3AJ Fig. 1 Fig. 1A Fig. 2 F3 sli 2s2 Fig. 3

Description

- 1 AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT ORIGINAL Name of Applicant: SANGO S.A.S. di Cattani Rita & C. Actual Inventor: Sante Camilli Address for Service is: SHELSTON IP 60 Margaret Street Telephone No: (02) 9777 1111 SYDNEY NSW 2000 Facsimile No. (02) 9241 4666 CCN: 3710000352 Attorney Code: SW Invention Title: EXTERNAL SUPPORT FOR RESTORING COMPETENCE TO VENOUS VALVES BY TRACTION OF THEIR INTERCOMMISSURAL WALLS The following statement is a full description of this invention, including the best method of performing it known to us: File: 45065AUP00 -2 EXTERNAL SUPPORT FOR RESTORING COMPETENCE TO VENOUS VALVES BY TRACTION OF THEIR INTERCOMMISSURAL WALLS Field of the Invention 5 This invention relates to a device for restoring competence to venous valves. Background of the Invention Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common 10 general knowledge in the field. A device for restoring competenceto venous valves is known from International Application No. WO 97/40755 (inventor Zukowski), published on 6th November, 1997, having the title Device for Restoring Competence to Venous Valves, which is the closest prior art. 15 Zukowski's device is based on the discovery that an external force applied onto a vein, at the level of the coapting surfaces of an incompetent, slackened valve of such vein, flattens the vein with the aim to extend the cusps of the valve laterally, taking up their slackening and bringing them into apposition, restoring the competence of the vein. 20 So Zukowski's device features a support for applying a compressive, corrective force to an incompetent vein. Zukowski discloses a support having a pair of opposite compression membranes which are identical, and generally rectangular. The membranes may have an elliptic or arcuate configuration, or may be flat with curved ends; they are joined together by an 25 integrally formed, intermediate hinge portion which, when the support has been positioned about a valve, generally extends axially with respect to the vein and is placed to be adjacent to one of the commissures where the cusps of the valve attached to opposite walls of the vein meet; the width of the hinge determines the compressive force applied by the support to the valve. The device is implanted by suturing the free 30 edges of the two rectangular members. The sutures perform the same function as the hinge, and they can regulate the compressive force of the device on the venous walls by their degree of tightening. Problems are associated with Zukowski's device. Zukowski's device has two compression membranes which are continuous 35 surfaces. Owing to such continuity, to implant it, it is necessary to completely clear the - 2a posterior wall of the vein from surrounding tissues, and from all eventual collateral veins. Moreover, for the same reason it is not suitable for curing an incompetent valve located at the confluence of another vein owing to the asymmetry and anatomical variability of the confluence itself. 5 Moreover, the compression from outside envisaged with Zukowski's device, actually does not ensure a contemporaneous increase of the intercommissural diameter per se. It is a disadvantage of Zukowski's device that its compressive action actually is not reliable as regards its corrective action. In fact, it is not sure that applying antero-posterior compressive forces though 10 reducing the antero-posterior diameter of the vein, forcedly determines an enlargement of the latero-lateral intercommissural diameter of the vein valve, because, really, in vivo: depending on the normally arising contraction of the muscular component of the venous wall during the surgical dissection of the vein from the surrounding tissues; depending on blood pressure inside the vein, and, depending on hormone-, or 15 drug- induced contraction of the muscular component of the venous wall, the vein is not in its final condition, as really turns out to be hypothesised in the spirit of Zukowski's device, so that a calibration thereof is difficult and probably incorrect. Moreover, the venous spasm directly consequent to surgical manipulation reduces the diameter of the blood-vessel circumferentially, so that one does not have 20 the best apposition of the two valve cusps and therefore it is not possible to check the valve competence intraoperatively, i.e. during an operation. It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. It is the object of an especially preferred form of the present invention to provide 25 for a device for restoring competence to venous valves. Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to". 30 Although the invention will be described with reference to specific examples it will be appreciated by those skilled in the art that the invention may be embodied in many other forms. Summary of the Invention 35 According to a first aspect of the present invention there is provided a traction- - 2b acting external support for restoring valvular competence to veins, to be implanted about a vein longitudinally, i.e. along the length of the vein; including two arcuate frame shells, having longitudinal sides, in an elongated material; said frame shells respectively being a posterior or deep frame shell and an anterior or superficial frame shell; said 5 posterior frame shell including two branches of said elongated material penetratingly shaped for an easy insertion of the posterior frame shell behind the posterior wall of the vein, through two paths prepared by the surgeon; each frame shell including a respective traction side including longitudinal rectilinear side traction branch means; said two frame shells being conformed to be juxtaposed to each other about the vein by 10 their longitudinal sides; said traction sides being intended to be engaged to the vein by opposite valve intercommissural walls by means of surgical sutures to dilate the intercommissural diameter of the vein by traction, so as to absorb the slackening of an incompetent venous valve by extending its cusps. According to a second aspect of the present invention there is provided a 15 method for fabricating an external support defined according to the first aspect of the present invention, or according to a first aspect of the present invention wherein one or both said frame shells are provided with hook means for engaging a vein by opposite valve intercommissural walls thereof, to dilate the intercommissural diameter thereof by traction, including cutting a foil or tube-shell material, e.g. in a plastic material or in a 20 metal, such as laser-cutting a metal foil. According to a third aspect of the present invention there is provided a method for fabricating an external support defined according to the first aspect of the present invention, or according to a first aspect of the present invention wherein one or both said frame shells are provided with hook means for engaging a vein by opposite valve 25 intercommissural walls thereof, to dilate the intercommissural diameter thereof by traction, including moulding a plastic material. The critical differences between the support of this invention and Zukowski's device are the following ones: (a) the inventive support acts by traction, as opposed to compression; (b) it is a device made as a frame shell, as opposed to continuous 30 membranes; (c) the true working parts of it, in its traction work, are the sutures made by the surgeon, as opposed to Zukowski's device which only requires sutures to be closed. Preferred embodiments are set forth in the subclaims. It is also the subject matter of this invention a method for producing the external 35 support taught by it, by an integrated fabrication according to Claim 9 or 10.

- 2c It is an advantage of the external support of this invention that it can be inserted after an extremely simple dissection of a posterior or deep passage tunnel. The surgeon only has to prepare two paths, without having to dissect the vein all over the length thereof. It can be inserted by easy-insertion branches of elongated material thereof 5 through such passages. As the dissection is lesser than in Zukowski's device, the related venous spasm is lesser too. This facilitates the significance of the known 'milking manoeuvre', which is less dependable, or not feasible at all, under spasm. This invention will be best understood based on the following detailed disclosure of non-limiting preferred embodiments thereof, given in reference to the enclosed 10 drawings, wherein: -3 Figure 1 and Figure 1A respectively show a posterior and an anterior frame shell of the inventive external support, in a preferred embodiment; Figure 2 shows the two frame shells of Figures 1 and 1A juxtaposed to each other in an assembled condition, defining an ellipse-like tunnel interior to receive a vein 5 therein, and Figure 3 schematically shows a vein restored to its competent condition by traction of its valve intercommissural walls by means of the inventive external support, once engaged by the sutures by the same intercommissural walls. The external support includes two arcuate frame shells in an elongated material, 10 respectively a posterior or deep frame shell 1 (see Figure 1) and an anterior or superficial frame shell 1A (see Figure 2). The external support is intended to be implanted about a vein longitudinally, i.e. along the length of the vein. The two frame shells are to perform different functions. Posterior frame shell 1 includes proximal and distal penetratingly shaped 15 branches of the elongated material, for an easy insertion of the posterior frame shell behind the posterior wall of a vein through two paths prepared by the surgeon, without the need for the ligation of eventual collateral veins. The easy insertion branches according to the preferred embodiment depicted in the Figures are proximal and distal narrow bends 2, 3 of the elongated material, having apices shaped as eyelets 2', 3'. 20 Narrow bends 2, 3 are centrally in continuity with each other by a large, central bend 4. Anterior frame shell 1A has the same structure as posterior frame shell 1, with a proximal bend 2A with an eyelet 2'A; a distal bend 3A with an eyelet 3'A and a central bend 4A, but proximal and distal bends do not have to be shaped penetratingly. The two frame shells have a respective longitudinal side of their arc-like shape 25 intended to constitute a traction side. Such traction sides include respective longitudinal rectilinear side traction branches of the elongated material. According to the preferred embodiment, as depicted in Figures 1 and 1A, the traction branches are free-end branches 5, 5' for posterior frame shell 1, and 5A, 5'A for anterior frame shell 1A. The free-end traction branches 5; 5A; 5', 5'A respectively stem as continuations of proximal 30 branches 2p; 2Ap, and of distal branches 3d; 3Ad of proximal 2, 2A and of distal 3, 3A bends of anterior 1 and posterior 1A frame shells, respectively. Central bends 4, 4A arrive onto the level of the longitudinal traction side of the arc-like shape of the frame shells. The free-end configuration for the traction branches serves to give a degree of elasticity for a better longitudinal flexibility thereof. 35 The two frame shells are to be juxtaposed to each other about a vein to be cured by the sides of their arcuate shapes - turning their concavities to each other - to -4 assemble the support as depicted in Figure 3, defining an ellipse-like tunnel to receive vein V thereinto. The assembled external support S is shown in Figure 2. In this preferred embodiment, the frame shells are assembled by making free-end traction branches 5, 5' of posterior frame shell 1 to pass into eyelets 2'A, 3'A of anterior frame 5 shell 1A, and making free-end traction branches 5A, 5'A of anterior frame shell 1A through eyelets 2', 3' of posterior frame shell 1. So the eyelets form means for reciprocal reversible mechanical connection of the frame shells. The external support has a proximal section formed by proximal branches 2p, 2Ap, and a distal section formed by distal branches 3d, 3Ad, and a central section 10 midway therebetween. The front-rear diameter of the support can decrease from the central section to the proximal and the distal section, to emulate the normal anatomic shape of natural valves, which favours the haemodynamic closing of the valves. Proximal branch 2p of posterior frame shell 1 can be arcuate with its concavity outwards, as shown in Figure 1, whilst proximal branch 2Ap of anterior frame shell 1A 15 can be arcuate with its convexity outwards, as shown in Figure 1A. In this way the external support, once assembled from frame shells 1, 1A as shown in Figure 2, has an inclined mouth 2p, 2Ap, which can conform itself to the confluence of two veins, at a proximal section thereof. Referring to Figure 3, the inventive external support is mounted about a vein V 20 with the longitudinal traction sides of the two frame shells respectively by opposite valve intercommissural walls iw1, iw2. It operates the restoring of the right apposition of the incompetent valve cusps by absorbing their slackening by traction. The traction force is applied onto the intercommissural walls iw1, iw2 of the venous valvular bulb by means of well known surgical sutures s1, s2 and is exerted along the intercommissural 25 diameter - so along valve cusps c1, c2 - to dilate it, extending the cusps and absorbing their slackening. Surgical sutures s1, s2 respectively engage traction branches 5, 5'; 5A, 5'A to opposite intercommissural walls iw1, iw2. The surgical sutures can also engage central bends 4, 4A of the frame shells protruding onto the longitudinal traction sides of the frame shells. In Figure 3 the eccentric ellipse-like shape of vein V, which 30 normally has a circular cross-section, under the action of the inventive support represents the effect of the traction of the latter once engaged by the sutures by the same intercommissural walls. One frame shell or both frame shells can be laterally provided with hooks for engaging a venous wall by opposite valve intercommissural walls, to dilate the 35 intercommissural diameter by traction. The hooks perform the same function as the sutures, i.e. they act the traction.

-5 As an alternative embodiment, the frame shells can be integral to each other, being connected to each other by a hinge by a longitudinal side thereof. The elongated material can be metal wire having good flexibility and elasticity, e.g. Nitinol@, or medical grade steel such as AISI 316. 5 However, the elongated material may also be e.g. a biocompatible plastic material, e.g. tetrafluoroethylene such as Teflon@, polypropylene, polyethylene. According to this invention a method is envisaged for fabricating the external support taught by it in its integrated form, including an integrated fabrication step, such as cutting a foil or tube material, e.g. in a plastic material or in a metal, such as laser 10 cutting a metal foil; or such as moulding a plastic material. In such a method a stage can be envisaged of fabricating the traction-acting hooks integratedly to the frame shells. In such a method when starting from a foil material a step is envisaged of folding the foil material to create a longitudinal hinge. 15 When starting from a tube material, the tube is suitably shaped conformingly to the final arcuate, ellipse-like shape of the final support. This invention has been disclosed referring to specific embodiments thereof, but it is to be understood that variations can be made thereto, without so departing from the scope of protection thereof, which is only restricted by the appended claims. 20

Claims (10)

1. A traction-acting external support for restoring valvular competence to veins, to be implanted about a vein longitudinally, i.e. along the length of the vein; 5 including two arcuate frame shells, having longitudinal sides, in an elongated material; said frame shells respectively being a posterior or deep frame shell and an anterior or superficial frame shell; said posterior frame shell including two branches of said elongated material penetratingly shaped for an easy insertion of the posterior frame shell behind the posterior wall of the vein, 10 through two paths prepared by the surgeon; each frame shell including a respective traction side including longitudinal rectilinear side traction branch means; said two frame shells being conformed to be juxtaposed to each other about the vein by their longitudinal sides; said traction sides being intended to be engaged to the vein by opposite valve intercommissural walls by means of 15 surgical sutures to dilate the intercommissural diameter of the vein by traction, so as to absorb the slackening of an incompetent venous valve by extending its cusps.

2. An external support according to claim 1, wherein one or both said frame shells 20 are provided with hook means for engaging a vein by opposite valve intercommissural walls thereof, to dilate the intercommissural diameter thereof by traction.

3. An external support according to claim 1 or claim 2, wherein said frame shells 25 are separate from each other, being able to be assembled to each other about a vein to be cured by surgical sutures.

4. An external support according to claim 3, wherein said two frame shells are endowed with reciprocal reversible mechanical connection means, such as 30 eyelets.

5. An external support according to claim 1 or claim 2, wherein said two frame shells are integral to each other, being connected to each other by hinge means by a longitudinal side thereof. 35 -7

6. An external support according to any one of the preceding claims, wherein the front-rear diameter thereof longitudinally decreases frnm a mantral ,eotinn thereof to a proximal section and to a distal section thereof. 5

7. An external support according to any one of the preceding claims, wherein a proximal extremity section of said posterior frame shell is arcuate with the concavity turned outwards, whilst a corresponding proximal extremity section of said anterior frame shell is arcuate with the convexity outwards. 10

8. An external support according to any one of the preceding claims, wherein said elongated material is a biocompatible material, selectable among metals, medical grade steels, plastics, polyesters, polypropylenes and polyethylenes.

9. A method for fabricating an external support defined according to claim 5, 15 including cutting a foil or tube-shell material, e.g. in a plastic material or in a metal, such as laser-cutting a metal foil.

10. A method for fabricating an external support defined according to claim 5, including moulding a plastic material. 20 Dated this 2 01h day of June 2012 Shelston IP 25 Attorneys for: SANGO S.A.S. di Cattani Rita & C.