FIELD OF INVENTION

The field of this invention lies within the field of surgical methods and devices. In particular, it lies within the specific field of a method for implanting a transapical heart valve and instruments used in the method. BACKGROUND

Heart surgery is becoming increasingly less invasive for patients. This is due to advancements of technology catching up with the preferences of patients who typically desire lower-risk procedures with a favourable outcomes and least possible trauma. Nowadays, many forms of heart surgery typically require only small incisions to obtain an outcome similarly favourable to that achieved using median sternotomy.

A common example of heart surgery being less invasive relates to the treatment of coronary artery disease. The treatment of coronary artery disease can now be carried out using balloons, stents and catheters. Another typical example of less invasive heart surgery relates to heart valve surgery in part due to a new generation of heart valves which have been introduced into the market. Examples of these new valves include percutaenous and transapical valves, which can be placed within a diseased valve using catheters from the groin via a small incision in the tip of the heart.

These procedures are carried out on a still-beating heart but their use still poses difficulties and there are limitations pertaining to their use. Such procedures may be (due to medical guidelines and directives) restricted to "no-option" patients, and the aged (usually above 80), particularly those who may not survive an open-chest procedure. Furthermore, implantation of these valves may be carried out within a diseased valve (due to the non-removal of the diseased valve and adjacent tissue) and result in adverse complications, such as, for example, prosthesis migration, paravalvular leak, embolism leading to stroke, conduction deficits, and so forth. The aforementioned issues also apply in relation to transapical aortic stents.

It should be noted that the aforementioned procedures do not involve removal of the diseased valves. Although the mortality rate resulting from the aforementioned procedures has been reduced, the failure risk is still substantial and prevents the use of the aforementioned procedures for younger patients. This has consequently led to the aforementioned procedures being carried out very rarely, and they are not readily available to a majority of patients who suffer from heart valve disease, particularly when more than one valve is affected. Currently, another problem stems from the intense competition by companies who engage in percutaneous and transapical valve programs. The substantial investment sunk into the programs by the companies has led to high prices for the valves and investment on non-standard infrastructure (for example, hybrid operating theatres) so as to be equipped to carry out the procedures. Consequently, the high cost is undesirably passed onto the patients.

SUMMARY

There is provided a method for implanting a transapical heart valve. The method includes cross-incising an apex of a heart; locating a cardioscopic instrument port at the apex of the heart; introducing a plurality of endoscopic instruments via the cardioscopic instrument port; using an internal retractor to keep a ventricle distended; excising both a diseased valve and debris from the ventricle; and locating a transapical valve at a position of the diseased valve. It is advantageous that the implantation of the transapical valve is carried out using direct vision enabled by an endoscope within the plurality of endoscopic instruments. The method may further include stitching the transapical valve to immobilize the transapical valve and may also further include testing of the transapical valve using the plurality of endoscopic instruments to ensure on-site workability of the valve.

It is advantageous that the transapical valve anchors itself at the position of the diseased valve during antegrade fixation using either an expandable base or fixation arms.

There is also provided a cardioscopic instrument port beatable at an apex of a heart. The cardioscopic instrument port includes a plurality of channels which individually allow the passage of shafted pediatric-thin endoscopic instruments and optical scopes into the heart. It is preferable that the cardioscopic instrument port is secured to the heart using purse-string suturing around the apex of the heart.

In another aspect, there is provided an internal retractor device comprising a plurality of biased limbs arranged to be introduced into a ventricle of a heart, the biased limbs being arranged to maintain the ventricle in a distended state.

There is also provided a transapical heart valve usable to replace a diseased heart valve, the transapical heart valve including either an expandable base or a plurality of fixation arms. Preferably, the expandable base allows the transapical heart valve to anchor itself during antegrade fixation at a position of the diseased heart valve. Similarly, the plurality of fixation arms may latch onto a mitral valve annulus.

In a final aspect, there is provided a camera for use at a surgery operation site via introduction through a main operative incision, the camera including an imaging module and a securing mechanism. The securing mechanism may be a mechanism such as, for example, a clip, an elongate structure with a screw thread, an adhesive surface and so forth. The camera may also include an illumination module, whereby the illumination module is for illuminating the surgery operation site. DESCRIPTION OF FIGURES

In order that the present invention may be fully understood and readily put into practical effect, there shall now be described by way of non-limitative example only preferred embodiments of the present invention, the description being with reference to the accompanying illustrative Figures.

Figure 1 shows a process flow of a method of implanting a transapical heart valve.

Figure 2 shows an embodiment of a cardioscopic instrument port usable in the method of Figure 1.

Figure 3 shows an embodiment of a left ventricular internal retractor usable in the method of Figure 1.

Figure 4 shows an embodiment of an expandable-anchored valve usable in the method of Figure 1.

Figure 5 shows an embodiment of a cardioscopic ablator usable in the method of Figure 1.

Figure 6 shows an embodiment of endoscopic tools usable in the method of Figure 1.

Figure 7 shows various embodiments of an un-mounted endoscopic camera.

DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to Figure 1 , there is provided a process flow for a method 20 for implanting a heart valve. The heart valve may be a transapical heart valve.

In the method 20, a small (4 - 5cm) incision is made in a patient's inframammary, anterolateral chest region (22) to allow entry into the chest cavity. The patient is then double lumen intubated so as to deflate the unilateral lung (24). An endoclamp is also simultaneously introduced through a first groin vein (26) while the Anesthesiologist performs transesophageal echocardiography (TEE) (28).

Subsequently, arterial and venous cannulas are introduced through a second groin vein and a jugular vein respectively to start cardiopulmonary bypass (CBP) (30). The pericardium is then opened (32), and Teflon strips are placed around the tip of the heart (34) while the heart is suspended against the chest wall. The heart is then arrested over the earlier-introduced endoclamp (36), while C02 is insufflated into the chest.

Once the heart is arrested, a small, 1cm cross-incision is carried out at the apex (left or ride ventricle, depending on the valve that needs to be targeted) (38) and a special port to fit these instruments in the apex (cardioscopic instrument port 80 as shown in Figure 1 ) will be located (40) at the apex. The cardioscopic instrument port 80 may be secured to the apex using purse-string suturing around the apex of the heart. Shafted pediatric-thin endoscopic instruments and optical scopes (no bigger than 5 mm, alternatively a bronchoscope - both equipped with a camera) are subsequently introduced into the heart through the cardioscopic instrument port 80 (42).

Referring to Figure 2, there is shown the cardioscopic instrument port 80 which is locatable at an apex 82 of the heart 84. The cardioscopic instrument port 80 includes a plurality of channels 86, 88, 90 which individually allow the passage of shafted pediatric-thin endoscopic instruments 87 and optical scopes 89 (no bigger than 5 mm, alternatively a bronchoscope - both equipped with a camera) into the heart. The cardioscopic instrument port 80 may be secured to the heart 84 using purse-string suturing 81 around the apex 82 of the heart 84. The cardioscopic instrument port 80 may be made from for example, rubber, silicone and so forth. Referring back to the method 20, a diseased valve is directly visualized once the heart is vented over a suction channel of the scope. An internal retractor device with a plurality of biased limbs will be introduced through the apex of the heart into an appropriate ventricle to keep it distended (44) subsequent to evacuation of blood. Next the diseased valve is excised and all debris flushed out and aspirated (46). Referring to Figure 3(b), there is shown the internal retractor device 120 with the plurality of biased limbs 122 when in an extended mode in the heart 84. The internal retractor device 120 may be made from, for example, nitinol, steel, silicone, and so forth. The internal retractor device 120 may preferably have elastic properties. Figure 3(a) shows a collapsed ventricle of the heart 84.

In the method 20, an enhanced transapical valve is used and located in a typical position in the heart (48). Figure 4 shows a depiction of the enhanced transapical valve. Figure 4(a) shows a first version 150 used for an aortic valve 151 while Figure 4(b) shows a second version 160 used for a mitral valve 161. The first version 150 is shown in a pre-deployed state 150(a) and a deployed state 150(b). The first version 150 includes an expandable base 152 which allows the first version 150 to anchor itself during antegrade fixation at an appropriate position in the heart so that there is no slippage of the valve into the aorta to cause embolism. The second version 160 is shown in a pre-deployed state 160(a) and a deployed state 160(b). The second version includes a plurality of biased fixation limbs 162 which latch onto the mitral valve annulus 164.

If necessary, a fixation stitch may be carried out to immobilize the valve in the typical position (50), following testing for patency of the coronary ostia. These can also be directly visualized through the optical scope passing through the cardioscopic instrument port 80.

Next the appropriate ventricle is filled with saline and de-aired under both TEE control and direct scope vision (52). The valve can also be tested on the spot with the shafted pediatric-thin endoscopic instruments passing through the cardioscopic instrument port 80 (54) so as to ensure on-site workability of the valve. Arrhythmias may also be treated through the same access position. The instruments will be passed cardioscopically through the mitral valve to the left atrium under camera vision, and the usual pattern of radiofrequency lesions will be set into the left atrial wall (using a lengthened atrial ablator device). The lengthened atrial ablator device is shown in Figure 5 and may be known as a cardioscopic ablator 180. The cardioscopic ablator 180 is of a length which is able to reach into an atrium of the heart through the mitral valve 181.

Finally, the endoclamp is released and the heart resumes normal function. The apex is closed over the pledgeted stitches as usual, and a chest tube is inserted to complete the entire procedure. If a dissection or aortic aneurysm are present, the same route can be used to deliver stents carrying valves (or bare stents) into the aorta in an antegrade fashion. This may involve deep hypothermic circulatory arrest, and identification of the true and false lumina of the ascending aorta, as well as the site of primary intimal tear (PIT). All aspects of the aforementioned procedures may be carried out using robotics.

The method 20 enables everything to be carried out using direct vision, rather than through fluoroscopy. The diseased valve and all debris are removed and the valve-prosthesis is implanted at an appropriate position, and checked for leaks and stability. In addition, mitral valve replacements, ventricular septal defects, mitral valve repairs, implanting of epicardial electrodes can also be simultaneously carried out using direct vision. Hence the procedure is much more precise and is able to be completed with a lower incidence of complications. Compared to procedures using percutaneous valves, the patient's heart is arrested for up to 30 minutes while the patient is under general anesthesia. The patient correspondingly does not experience ventricular fibrillation which is typical for percutaneous and transapical procedures. With regards to the aortic stenting, the method 20 offers direct view and precise positioning of a stent graft or conduit, identification of the primary intimal tear (PIT) through direct visualization and an all-in-one antegrade approach (in accordance with the blood stream direction), as opposed to the currently utilized invariable retrograde approach, using much longer, expensive and labor- intensive processes through the groin arteries. Furthermore, the patient's exposure to radiation will be kept to a minimum while the method 20 is carried out, compared to typical percutaneous, transapical, transfemoral, and retrograde procedures.

In the method 20, a lateral mini-thoracotomy access may alternatively be used. It would be practical to be able to carry out the replacement of both valves through the side while carrying out a single procedure. For this purpose, some new tools are used as shown in Figure 6 (Figure 6 depicts right atrium 256 of the heart 84), such as intracardiac lights and mirrors 250, as well as angulated tools 252, in order to reach the aortic valve 254 through the mitral valve. Special anchoring valves may be utilized for this procedure, even though the currently utilized transapical valves or percutaneous valves may still be used, with some amendments.

All endoscopic surgery is typically done with the use of cameras mounted on endoscopes. Referring to Figure 7, there is shown several forms of a camera which are not mountable on an endoscope and able to be fixed in place at surgery operation sites via access through a main operative incision. Figure 7(a) shows a button-like camera 350 which includes a securing structure 352 and is able to be clipped onto a chest wall. Figure 7(b) shows another button-like camera 360 which includes a clip 362 and is able to be clipped onto heart tissue, or any other structure. Figure 7(c) shows another button-like camera 370 which includes an elongate structure 300 with a screw thread for tissue stabilization. Figure 7(d) shows another button-like camera 380 with an adhesive surface 302 such as, for example, velcro. Finally, Figure 7(e) shows a button-like camera 390 which includes a light source 304 for illuminating an image captured by the button-like camera 390. Each of the cameras shown in Figure 7 may be, for example, a one-way camera, an implantable camera, a remote controlled camera and so forth. Each of the cameras includes an imaging module. Each camera may be collected and sterilized for subsequent use. Alternatively each camera may be disposable after a single instance of use.

Whilst there has been described in the foregoing description preferred embodiments of the present invention, it will be understood by those skilled in the technology concerned that many variations or modifications in details of design or construction may be made without departing from the present invention.