TRANSCATHETER RESECTION APPARATUS FOR NATIVE OR BIOPROSTHETIC HEART VALVES

FIELD OF INVENTION

This invention relates to the resection of native or bioprosthetic heart valves, usually stenotic valves, by means of a transcatheter minimally invasive procedure.

BACKGROUND

The increase of life expectancy in Western countries over the past 30 years has resulted in an exponential increase of elderly patients presenting for cardiac surgery. In this population, aortic stenosis is the most important acquired heart disease, with a prevalence of 4.8% in patients aged >75 years, and represents >60% of the indications for cardiac surgery in elderly patients. Despite the good results reported by many authors with conventional aortic valve replacement (AVR) in elderly patients, many patients are denied surgery because of the high operative risk. In this frail population, transcatheter aortic valve implantation (TAVI) can be a good compromise to achieve good results and minimize morbidity and mortality [8].

TAVI was introduced into clinical practice in 2002 as a rescue approach for patients presenting with symptomatic severe aortic stenosis but not eligible for conventional AVR. This technique allows implantation of a balloon expandable bioprosthesis without resection of the native aortic valve. Several complications have been described as a consequence of the residual highly calcified valve being squeezed between the aortic wall and the stent of the implant. This can result in deformation of the metal stent and para-valvular leakage, risk of occlusion of the coronary ostia, or central and peripheral embolization of valvular debris. In a recent report, it has been hypothesized that it is necessary to resect the native calcified aortic valve before TAVI in order to avoid those complications and several authors have reported new experimental methods of endovascular aortic valve resection to reach the same goal.

In 2002, Cribier et al. crossed the frontiers for the treatment of severe aortic valve stenosis by performing the first human percutaneous aortic valve implantation. However, TAVI can result in severe complications, and the lack of resection of the calcified native valve is an issue in terms of paravalvular leakage, cerebral embolization and need for permanent pacemaker implantation.

The mechanisms of these complications are probably related to the lack of resection of the native aortic valve. The incompressibility of the leaflet calcium induces a non-apposition of the TAVI on the annulus, resulting in a paravalvular leak. The over-compression of the calcified native leaflet on the conduction tissue induces an atrioventricular block and the need for new pacemaker implantation. Fragmentation of the leaflet calcium during the positioning and deployment of the TAVI may produce some embolization of debris into the brain, the coronary system or elsewhere.

Another cause of cerebral embolization could be related to the fact that the placement of the TAVI into the native calcified valve creates a dead space between the native leaflets and the aortic wall.

This space can be the niche for thrombus and debris that could embolize later on. This could provide an explanation for the high rate of cerebral embolization even 2 years after TAVI. If the native leaflets are removed, then this space could be washed continuously by the blood coming through the TAVI. The rate of thromboembolic neurological events at 30 days, 1 and 2 years, reported by the PARTNER trial investigators, was 5.5, 8.3 and 11.2%, respectively. Data from the UK TAVI Registry reported a stroke rate after TAVI of 2.8-4.1%. Furthermore, a high rate of silent ischemic lesions, ranging from 66 to 71%, in diffusion-weighted magnetic resonance imaging (MRI) studies, has been showed. Astarci et al. reported an even higher rate of silent ischemic lesions of 95% detected by MRI. The high rate of silent ischemic lesions is associated with embolization of debris during the TAVI procedure. Resection of the native calcified aortic valve prior to TAVI should reduce the incidence of complications related to the calcium loss as well as the injury of the surrounding structures due to compression. The AVIC proposed by the Kiel group and the collection chamber proposed by the Essen and Brussels groups are based on balloon sealing systems. Unlike the other two devices, which need to be equipped with an additional tool for protection of the coronary ostia to prevent embolization of debris and an adequate aspiration system to remove the resected fragments after the resection, the device designed by the Brussels group allows direct collection of debris during the resection through to the inner chamber between the nitinol blade and the supravalvular balloon.

However, in all these systems the balloons might be damaged during the resection process, compromising the procedure and exposing the patient to massive embolization of debris.

Another important factor to analyze is the time necessary to execute the resection. Salizzoni et al. used an animal model (in vivo swine) to test the effects of beating heart off-pump aortic valve resection in preparation for aortic valve implantation. The removal of the aortic valve caused a massive aortic regurgitation, associated with an immediate reduction in the systolic and diastolic arterial pressure, which equalized the left ventricular end diastolic pressure. The coronary flow decreased by 50%, and cardiac ischemic changes in the ECG appeared in an average of 30.8 s.

In comparison to the works of Quaden et al. (the Kiel group), who reported a resection time ranging from 2.3±0.3 to 12.2±0.8 min for three leaflets using a high-pressure water stream scalpel and from 5.5±2.3 to 6*3.5 min per leaflet using a thulium: YAG laser system, the resection time of blade-based resection systems is shorter and appears to be more appropriate for minimally invasive aortic valve replacement and seems to be more realistic for an endovascular approach before TAVI implantation in an off-pump, beating heart procedure.

In comparison to the work of Wendt et al., the force needed to resect a human calcified valve was higher in Astarci's report. One possible explanation reported by the authors is the fact that calcification in human valves might be stronger than the commercially available bioprostheses. A second explanation could be that natural calcification over the course of many years could lead to stronger calcification than an artificial calcification process performed within a few weeks.

Finally, the reason could also be related to the characteristics of the device and blades that could influence the cutting process.

The ideal device should be easy to handle and easy to remove in the event of a failing procedure. It should provide rapid and precise resection of a heavily calcified valve without production of debris during the resection. It should include an aortic isolation chamber to collect the resected valve and protect the coronary ostia. More importantly, it should be associated with a system of TAVI implantation.

Blade-based devices seem to be appropriate for a rapid endovascular resection within a few seconds, performed in the beating heart and off pump, whereas with laser and water jet devices the time for resection is significantly longer and necessitates cardiopulmonary bypass or a ventricular-arterial shunt during the resection. Brecht et al. proposed a blade-based device including a resection and implantation system.

Although the idea of this device seems to be promising, the lack of protection for the coronary ostia during the resection could expose the patient to coronary embolization.

Furthermore, a balloon-based isolation system can easily be damaged during the resection, compromising the whole procedure.

Finally, another possible advantage of these devices should be underlined. Resection before TAVI is the final goal, but a resection device could be helpful during a sutureless prosthetic aortic valve implant procedure. The only benefit of a sutureless valve compared with a standard bioprosthesis is the time gained during placement. The use of a fast resection device could enhance the efficacy of sutureless procedures.

In summary the resection of the calcific native aortic valve or bioprosthesis and the implant of a specifically designed new generation TAVI can bring to the patients several clinical advantages in comparison with the current TAVI procedures:

- a) Significant reduction of the perivalvular leaks (PVL) thanks to a better fitting of the prosthesis into a defined and regular annular ring;
- b) Reduction of the incidence of atrioventricular (A-V) blocks requiring pacemaker implantation;
- c) Reduction of the coronary ostia occlusions reducing the dead space between the prosthetic leaflets and the aortic root. In TAVI the native leaflets are pushed towards the coronary ostia;
- d) Reduction of the continuous embolization of calcium debris. Neurological complications are continuing even after 2-3 years from TAVI implants;
- e) Strong mitigation of the patient-prosthesis mismatch (PPM). The resection of the native valve allows the implant of a larger size valve prosthesis reducing the risk of PPM and leaving space for a future further resection of the prosthetic valve.

SUMMARY OF THE INVENTION

The present invention provides a different and improved apparatus for the resection of native or bioprosthetic heart valves.

It also encompasses a use of the said apparatus.

The invention is particularly useful for the replacement of atrioventricular valves or the trileaflets ones.

Such valves, when calcified are becoming progressively stiff due to a phenomenon of dystrophic tissue calcification. The outcome of this progressive pathology is an infiltration of hydroxyapatite crystals into the leaflets' fibroelastic structure. The resulting tissue has sometime a stone-like consistency and it is particularly difficult to be removed during heart valve replacement procedures.

The use of the apparatus according to the invention is based on a direct cutting of the diseased valve by means of a special surgical scissor.

The diseased valve extraction is completed by an accurate removal of the remaining calcific protruding boulders in order to prepare the implant site for sewing the next prosthesis implant.

The aim of this invention is to mimic the surgical valve excision through a non-invasive transcatheter interventional procedure. The extraction device is suitable to perform the excision of the diseased native valve or a degenerated bioprosthetic valve adopting a transcatheter procedure without any support of the extracorporeal circulation.

The basic concept of such device consists of three procedural steps that are solving critical issues still present in the current TAVI procedures.

The first one is locking the stenotic leaflets with a grasping system positioned internally the native valve. The second one is cutting in safe, quick, precise, easy and sharp way the leaflets of a diseased native valve or a bioprosthesis and the third one is the safe removal of the excised valve apparatus with a minimum encumbrance in the same catheter without or minimal debris embolization. This extraction procedure is intended to be conducted in presence of an embolic protection device, not described here, positioned in the ascending aorta to prevent cerebral and peripheral embolization.

The result of this valve extraction procedure, in a stenotic native valve, is an annular aortic ring of a predefined dimension, into which a sutureless transcatheter valve bioprosthesis can be implanted in the same procedure. In case the extraction procedure is conducted on a stenotic, previously implanted, bioprosthetic valve the final result is a bioprosthetic stent without the biologic functional component. In this case the naked bioprosthetic stent can be used as an anchoring support to implant a conventional TAVI bioprosthesis.

The success can be achieved providing a temporary valve support in absence of the excised native heart valve.

More precisely, the invention concerns a transcatheter resection apparatus for native or bioprosthetic heart valves comprising a leaflet grasping system and a leaflet cutting device, said grasping system and said cutting device being coaxially and longitudinally movable relatively to each other and wherein said grasping system is longitudinally oriented, characterized by the fact that the grasping system comprises a fixed portion and a rotating portion; said fixed portion being adapted to grasp a leaflet face and said rotating portion being adapted to grasp the opposite leaflet face.

According to a preferred embodiment, the native valve to be excised is inside the cutting device and outside the grasping system.

The grasping system may advantageously comprise barbs that are proximally oriented, also with different angulations, when they interact with a native leaflet.

The grasping system, when positioned inside the native valve, may expand to the desired diameter in a self-expanadble mode and/or by a mechanical support or a balloon. The grasping system furthermore comprises a fixed portion and a rotating portion; the fixed portion being adapted to grasp a leaflet face, such as the ventricularis side, and said rotating portion being adapted to grasp the opposite leaflet face, i.e. the fibrosa side.

The apparatus according to invention may also advantageously comprise an anchoring valve stent with a distal part providing a temporary valve function and a proximal part comprising the grasping system.

Preferably the anchoring valve stent has a clepsydra shape. With such a configuration the grasping system is located within the narrow portion of the anchoring valve stent.

In another embodiment the grasping system is separated from the temporary valve inside the anchoring valve stent. In this case the function of temporary valve can be assigned to a sutureless transcatheter valve prosthesis that at the end of the procedure will be repositioned and left in place as a definitive prothesis.

The invention also concerns the use of an apparatus as defined previously.

In this case, it comprises the following steps:

- proximally orienting the leaflets,
- grasping of the leaflets by the grasping system,
- cutting of the leaflets with the cutting device,
- removing the cut leaflet portions.

When an anchoring is also used, the proximally orienting of the leaflets is preceded by the positioning of the anchoring valve stent.

With the fixed and rotating portions of the grasping system, the leaflets are grasped on both faces.

Advantageously, the removal of the cut of the non-functional leaflet portions is followed by the positioning of a sutureless transcatheter bioprosthetic valve.

DETAILED DESCRIPTION OF THE INVENTION

The invention will be better understood in the present chapter, with some non-limiting illustrated examples.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1a Anchoring valved stent with a distal portion containing a prosthetic valve

FIG. 1b Proximal section of the anchoring valved stent showing the stent structures and the grasping elements act at locking the native valve leaflets

FIG. 1c distal section of the anchoring valved stent showing the trileaflet structure of the prosthetic valve

FIG. 2 Shows the fixed portion of a leaflet grasping system (the rotating portion is not shown on this figure). The intravalvular portion of the anchoring valved stent is provided with inclined barbs, penetrating the ventricularis layer, aimed at keeping firm the valve leaflets and locking them avoiding embolization after cutting

FIGS. 3a and 3b Show a complete grasping system showing an upper portion of the anchoring valved stent provided with barbs. This upper portion is rotating of almost 180° and grasps the fibrosa layer of the leaflet granting a complete lock of the leaflets

FIG. 4 Excision cutter with its blades in the distal portion

FIG. 5 Excision cutter placed over the anchoring valved stent

FIG. 6 Excision cutter just after completing the extraction of the native leaflets

FIG. 7 Anchoring valved stent with the temporary prosthetic valve positioned over the cutting rim and the leaflets captured. The excision cutter is not represented

FIG. 8 Valve excision and replacement system is represented. The system has two handles respectively dedicated to the control of the navigation catheter and the excision/removal of the native valve. the third one (the most proximal to the operator) is the handle dedicated to the control/release of the dedicated TAVI

FIG. 9 Insertion of the guidewire across the native valve

FIG. 10 Positioning of the navigation catheter into the aorta

FIG. 11 Navigation catheter crossing the native valve

FIG. 12 Dilator removed from the navigation catheter

FIG. 13 Deployment of the prosthetic valve below the native one

FIG. 14 Intermediate deployment of the anchoring valved stent showing the middle portion anchoring the native valve leaflets with the barbs.

FIG. 15 After full deployment the rotating grasp system is locking the leaflets from the fibrosa side

FIG. 16 Positioning of the excision cutter outside the excision valved stent

FIG. 17 Native leaflets' cutting procedure in progress. The excision cutter is pushed distally towards the aortic root

FIG. 18 Native leaflets are cut by the excision cutter at the base of the aortic root

FIG. 19 The entire valve excision system is moved proximally in order to engage the prosthetic valve across the rim left after the native valve excision

FIG. 20 The TAVI delivery system is entered inside the valve excision system and is positioned with its tip in the ventricle

FIG. 21 Distal portion of the TAVI is deployed just below the temporary prosthetic valve

FIG. 22 The entire system composed by the excision system and the TAVI is moved proximally into the aorta. The distal portion of the TAVI engages in the aortic root

FIG. 23 The TAVI is fully deployed in place

FIG. 24 The excision valve system, carrying on its content of excised native leaflets, is gradually compressed into the navigation catheter and then retrieved out of the patient

FIG. 25 to FIG. 30 describe a transfemoral procedure

FIG. 31 to FIG. 36 describe a mixed transapical and transfemoral approaches

FIG. 37 to FIG. 42 represent a procedure that is completed exclusively via transapical access

NUMERICAL REFERENCES USED IN THE FIGURES

- 1. Navigation catheter and it's dilator 1′
- 2. Anchoring valved stent with its proximal and distal structures
- 3. Structure of the stent carrying on the prosthetic valve
- 4. Prosthetic valve leaflets
- 5. Fixed portion of the grasping system of the anchoring valved stent. The barbs grasping the ventricularis (internal to the native leaflets) and the barbs grasping the fibrosa (external to the native leaflets) are both represented
- 6. Native aortic valve leaflet. 6a is the fibrosa side while 6 b is the ventricularis side
- 7. Barbs of the grasping system
- 8. Rotating portion of the grasping system grabbing the fibrosa side of the native valve leaflet
- 9. Excision cutter
- 10. Stent structure of the excision cutter
- 11. Blades of the excision cutter
- 12. Coronary arteries
- 13. Aorta's wall
- 14. Catheter tip of the excision valve system
- 15. Braided catheter body of the navigation catheter
- 16. Distal handle with steering control of the navigation catheter
- 17. Middle handle carrying on the control system of the excision system. Advancement, deployment and capture of the excision cutter and the anchoring valved stent
- 18. Proximal handle controlling the dedicated sutureless transcatheter valve prosthesis
- 19. Delivery system of the sutureless transcatheter valve prosthesis
- 20. Sutureless transcatheter valve prosthesis

DETAILED DESCRIPTION OF THE FIGURES

The excision valve system is composed by two devices designed to work together coaxially and with different functions. The first one internal 2 is called “anchoring valved stent” has the function to provide a temporary valve function 3,4 in the meanwhile the native leaflets 6 are blocked, in open position, by the barbs 7 placed in the middle portion of the stent (FIG. 1a, 1b, 1c). The second one external is called “excision cutter” 9 having a stent structure with blades, typically 6 to 12 or more, at its end.

The anchoring valved stent 2 has a clepsydra shape with an overall length of 70-80 mm. The proximal and distal portions are equal in diameter and larger (1 to 5 mm) than the middle one. The proximal portion is a stent-like structure designed to be easily collapsed into the navigation catheter 1. The smaller middle portion, when deployed, has a diameter that must be 40-60% smaller than the aortic root measured by CT scan imaging. It has the function to block the native stenotic leaflets 6 in open position, to retain them by means of grasping barbs 7 and in general term to maintain the aortic valve stable during the cutting procedure. The grasping barbs 7 are designed in order to avoid leaflets' embolization or their fragments during the excision procedure.

The distal portion 3 of the anchoring valved stent 2 is a valved stent. Its function is extremely important since it maintains the patient's hemodynamic stable during the procedure when the native leaflets are locked in open position. This prosthetic valve 4 is in general polymeric (silicone, polyurethanes and their co-polymers, polymeric impregnated synthetic fabric, a biologic origin tissue such as bovine, porcine or equine pericardialtissue, etc.) and highly collapsible having a temporary function. This distal portion of the anchoring valved stent 2 is positioned below the aortic root. The temporary prosthetic valve 4 is normally trileaflet but can be bileaflet or monoleaflet. The valve assembling technique over the distal portion 3 of the anchoring valved stent 2 can be different including liquid polymeric dipping, molding, stitching of polymer impregnated fabric, stitching of biologic tissues or others.

The native aortic leaflets 6 have two different anatomical sides; the ventricularis (internal side of the valve facing the blood flow ejected by the ventricle) 6b and the fibrosa 6a facing the aortic wall. The grasping system 5,8 (see FIGS. 2, 3a and 3b) has several barbs 7, placed at regular intervals and possibly with different lengths, grasping the ventricularis face 6b. The grasping system 5,8 has a portion 8, provided with barbs 7, rotating of 180° so that the barbs 7 can grasp the fibrosa side of the leaflet 6a. The result is that the upper portion of the native leaflets are locked at level of their free margin.

The rotating portions 8 are preferably at minimum of three (one for each leaflet) disposed at 120° radially. The barbs 7 of the rotating portions 8 can have a different length, shape and angle similar and opposed to those of the grasping system 5,8.

The excision cutter 9 in FIG. 4 has a stent structure with struts 10 and it is provided with blades 11 at the distal end. The structure must be easily collapsible but rigid enough, when deployed, to provide a precise cut of the leaflets at commissural level and the aortic root at the leaflets' base leaving a regular rim suitable to anchor, later on, a permanent sutureless prosthetic valve. In addition, the structure of the excision cutter 9 must be entirely covered by a thin fabric clot with the scope of capturing emboli (calcific debris and/or blood clots) generated during the cutting procedure but in the same time allowing the blood to flow through it. The blades 11 can have a variable number, typically from 3 to 12 with different length depending on the designed structures. The cutting procedure (FIG. 5) is generated by a rotation of the excision cutter 9 that has a relative rotational movement respect to the anchoring valved stent 2. The rotation and advancement of the excision cutter 9 can be manual (direct or de-multiplied) or automatic (controlled by an electric micro-motor, etc.). The diameter of the excision cutter is strictly conditioned by the predetermined diameter of the proximal portion of the anchoring valved stent. In fact, a small and controlled gap is kept between the two devices. The cutting diameter of the excision cutter must be inside a well-controlled and stable dimension avoiding any damage to the aorta's root or wall.

In FIG. 6 the cutting action of the excision cutter 9 is represented. The excision cutter 9 during the excision of the native stenotic leaflet 6 progressed distally towards the aortic root and the leaflets 6 are excised and retained by the anchoring valved stent 2.

In FIG. 7, after excision of the native valve, the excision cutter 9 has been removed through the navigation catheter 1. The anchoring valved stent 2 is then retracted proximally in order to engage the temporary prosthetic valve 3,4 inside the aortic root rim left after native valve excision. In an alternative embodiment the excision cutter 9 and the anchoring valved stent 2 can be removed together inside the navigation catheter 1 only at the end of the sutureless prosthetic valve implant procedure in order to minimize any embolic dissemination.

The complete excision valve system in FIG. 8 is represented. The excision valve system is controlled by two handles 16,18 while the proximal handle 18 is the one controlling the sutureless prosthetic valve implanted only at end of the native valve excision procedure. The system is provided with an outer catheter 15 ending with a tip 14 that allows the catheter 15 to enter into the access site vessel. The distal handle 16 provides the control of the excision cutter 9 while the middle handle 17 provides the control of the anchoring valved stent 2.

The sequence of the excision procedure is here below described.

The procedure is performed via puncture of the femoral artery and, after positioning an introducer, a guidewire is inserted. It crosses the native stenotic aortic valve till reaching the left ventricle (FIG. 9).

A steerable navigation catheter 1 with a dilator 1′ is inserted through the femoral artery over the guidewire and navigate the aortic arch reaching the native stenotic aortic valve (FIG. 10).

The navigation catheter 1 is then pushed across the native valve (FIG. 11).

The dilator 1′ of the navigation catheter is removed leaving it across the valve (FIG. 12).

The navigation catheter 1 is used like a hub to bring in place the necessary tools for stenotic native valve excision. Initially an anchoring valved stent 2 is deployed over the native leaflets 6 and placed across the native valve.

The navigation catheter 1 is gradually retracted, and the anchoring valved stent 2 is exposed. The distal portion of the anchoring valved stent 2, containing the temporary polymeric valve 3,4, is then deployed (FIG. 13).

The central portion of the anchoring valved stent (2) is then deployed and it is completed with the further deployment of the proximal portion (FIG. 14).

The anchoring valved stent 2 has a central portion (equipped with barbs 7 oriented outside the external surface with the function to retain the leaflets on their ventricularis sides, when excised, as described in FIG. 14) placed across the native valve with a diameter smaller than the native valve itself and a proximal and distal portion slightly larger. Another group of barbs (not shown in FIG. 14) retain the leaflets on their fibrosa sides. The distal portion of this anchoring valved stent 2, larger than the central one, is containing a polymeric valve able to support the patient's hemodynamics in the meanwhile the native valve is progressively disabled.

In the example represented in FIG. 15 the anchoring valved stent 2 has 3 rotating portions 8 preferably placed at 120° that retain the excised leaflets 6 on their fibrosa sides.

Then the proximal portion of the anchoring valved stent 2 if fully deployed (FIG. 16).

Through the same guiding catheter 1, the excision cutter 9 is entered over the anchoring valved stent 2 (FIG. 17).

The excision cutter 9 is larger than the proximal and distal portion of the anchoring valved stent 2. The excision cutter 9 is pushed forward over the anchoring device till coming in contact with the native aortic valve and starting the leaflets' 6 excision until complete valve excision (FIG. 18).

The excision cutter 9 is a dimension controllable or a pre-defined dimension self-expandable structure that is opening at a diameter slightly larger than the anchoring valved stent 2 and its cutting dimension is pre-defined by the operator. This excision cutter 9 has a coating outside (thin pore fabric material or a continuous polymeric film) aimed at impeding embolization of debris towards the coronary ostia and at its distal end is provided with a cutting mechanism 11 (e.g. up to 12 blades). The goal is providing a clean cutting surface at a precise diameter inside the aortic root to position a dedicated sutureless prosthetic valve. In order to prevent material embolization, the excised leaflets 6 are retained inside the interspace between the anchoring valved stent 2 structures 5,8, thanks to the barbs 7 positioned outside, and the excision cutter 9 (FIG. 18).

The two devices are then slightly retracted into the ascending aorta and the temporary valve 3,4 present in the distal portion of the anchoring valved stent 2 is fitted inside the rim of the aortic root with the aim to keep stable the patient's hemodynamics (FIG. 19).

In FIG. 20 the insertion of a sutureless transcatheter valve delivery catheter 19 across the excision valve system is represented.

A specially designed transcatheter valve prosthesis 20, collapsed into its delivery system 19, is inserted through the guiding catheter 1 and internally to the anchoring valved stent 2. It crosses the anchoring valved stent 2 and its distal valved portion 3,4 and is positioned into the left ventricle (FIG. 20).

The sutureless transcatheter valve prosthesis 20 is initially deployed (FIG. 21) distally to the temporary valve 3,4.

In the meanwhile, the entire excision system 2,9 is gradually retracted into the ascending aorta and the sutureless transcatheter valve prosthesis 20 is progressively deployed into the aortic root (FIG. 22, 23).

The delivery system of the sutureless transcatheter valve prosthesis 20 is then completely retrieved (FIG. 23).

As a final action the excision cutter 9 and the anchoring valved stent 2, containing the excised leaflets 6, are gradually collapsed into the guiding catheter 1 and retrieved out of the patient leaving the new sutureless transcatheter valve prosthesis 20 in place (FIG. 24).

In another example, described in FIG. 25 to FIG. 30, the final sutureless transcatheter valve prosthesis 20 can also act as a temporary valve in place of the valved portion 3 of the anchoring valved stent 2. One mandatory condition is that the sutureless transcatheter valve prosthesis 20 is designed to be fully recapturable inside its delivery catheter 19.

In this case the guiding catheter 1 is initially positioned in the ascending aorta just above the native aortic valve. The delivery catheter 19 is advanced, over the guidewire, and crosses the native valve 6. Then the sutureless transcatheter valve prosthesis 20 is partially deployed below the native aortic valve 6, retracting the delivery catheter 19 and granting its valve function as temporary valve. at this stage the entire excision system 2,9 is advanced. The excision system in this case is only composed by the anchoring valved stent 2 without the distal valved portion 3,4. The native valve 6 grasping and excision procedures are conducted as above described in FIGS. 2-7. When the excision of the native valve 6 is completed the excision system 2,9 is gradually retracted in ascending aorta above the sino-tubular junction leaving enough space for the deployment of the sutureless transcatheter valve prosthesis 20. At this stage the sutureless transcatheter valve prosthesis 20 is partially collapsed into its delivery catheter 19, re-positioned in the aortic root over the rim left by the excision of native valve 6 and re-deployed in position as a definitive prosthetic valve. At this stage the delivery catheter 19 is fully retracted out of the patients with its handle 18. The procedure is then completed collapsing the excision cutter 9 and the anchoring valved stent 2, containing the excised leaflets 6, into the guiding catheter 1. The handle 17 controlling the excision system 2,9 is then removed out from the patient. As last action the navigation catheter 1,15 is retracted out of the patient with its handle 16.

In another example (FIG. 31 to FIG. 36) the same procedure can be conducted via transapical approach. The transapical access is obtained placing a pursue string on the ventricular apex in a predetermined position by CT scan allowing to reach by puncturing the left ventricle, the native aortic valve. This access allows a direct orthogonal approach to the aortic valve. The navigation catheter 1 is introduced transapically and crosses the native aortic valve. The temporary prosthetic valve, mounted upside down, is deployed in ascending aorta (to prevent aortic regurgitation). The excision valve system 2,9 is then deployed and the native valve 6 resected using the excision cutter 9,10,11 following the same, above described, procedure. The final sutureless transcatheter prosthetic valve 20 is then implanted via transfemoral access.

In a further example (FIG. 37 to FIG. 42) the native valve 6 excision procedure can be entirely completed by transapical access using the final sutureless transcatheter prosthetic valve 20 also as temporary valve support. The sutureless transcatheter prosthetic valve 20 is partially deployed at level of mitro-aortic continuity below the native aortic valve 6. The grasping system 5,8, in closed configuration, is advanced through the sutureless transcatheter prosthetic valve 20 and is deployed. When the vative leaflets 6 are locked-up the excision cutter in closed configuration is inserted through the sutureless transcatheter prosthetic valve 20 and positioned over the grasping system 2,5,8. After complete excision of the native valve 6 the entire system, including the sutureless transcatheter prosthetic valve 20, is pushed cranially towards the Aorta with the aim to deploy in position the sutureless valve 20. When the sutureless transcatheter prosthetic valve 20 is fully deployed then the excision valve system 2,9 is progressively closed and retracted out the heart crossing the sutureless valve 20.

TRANSCATHETER RESECTION APPARATUS FOR NATIVE OR BIOPROSTHETIC HEART VALVES

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