WO2019045560A1

WO2019045560A1 - Device for making a cut in a tissue and method of using the device

Info

Publication number: WO2019045560A1
Application number: PCT/NL2018/050554
Authority: WO
Inventors: Paul Frederik Gründeman
Original assignee: Umc Utrecht Holding B.V.
Priority date: 2017-08-28
Filing date: 2018-08-27
Publication date: 2019-03-07
Also published as: NL2019458B1

Abstract

The present invention pertains to a device (1) for making a cut in a tissue at a predetermined site, the device comprising an elongated member (2, 20) having a lumen, the member having an opening (11) that connects the exterior of the member to the lumen, wherein the opening is to be positioned over the tissue at the site, a connector (4) for operatively connecting the lumen to a vacuum pump for reducing the pressure in the lumen in order to draw at least part of the tissue including the site into the member, a gas permeable tissue support (6) located in the lumen adjacent the opening, against which support the at least part of the tissue is drawn under the reduced pressure, and a cutting element (8) located in the elongated member for cutting the tissue drawn into this member at the said site, wherein in the device, the tissue support is movable with respect to the elongated member in a direction transverse to the plane of the opening.

Description

DEVICE FOR MAKING A CUT IN A TISSUE AND METHOD OF USING THE DEVICE

GENERAL FIELD OF THE INVENTION

The present invention in general pertains to a device for making a cut in a tissue at a predetermined site, in particular applicated through minimally invasive body access channel, e.g. a trocard. Such a device typically comprises as a basic member an elongated member having a lumen (which member can have for example a circular, oval, ellipsoid or other shape), the member having an opening that connects the exterior of the member to the lumen, wherein the opening is to be positioned over the tissue at the site. The device further typically comprises a connector for operatively connecting the lumen to a vacuum pump for reducing the pressure in the lumen in order to draw at least part of the tissue including the site into the lumen, a gas permeable tissue support located in the lumen adjacent the opening, towards which support the at least part of the tissue is drawn under the reduced pressure, and a cutting element located in the elongated member for cutting the tissue drawn into this member at the said site.

BACKGROUND ART

A cutting device as described here above is known from US 8,603,031. The device is particularly intended for accessing a pericardial space of the heart and includes a shaft having a cavity at a distal end. The opening of the cavity is positioned over the site of the heart where a cut is to be made. The shaft is provided with a suction lumen terminating in a distal port within the cavity and a hollow needle as a cutting element, which needle has a distal tip that protrudes into the cavity. The wall of the cavity acts as a tissue support for tissue drawn into the cavity in order to stabilize the tissue part, also called (tissue) bleb, into the cavity. Various arrangements are foreseen in order to make the device versatile in the sense that is can be used for example for different types of tissue and different cutting depths. These arrangements i.a. include different shapes of the cavity by having an inflatable section at the opening of the cavity, and different cutting element set-ups.

Another device for making a cut in a tissue is known from US 8,092,477. This device has as a basic member a trocar which has an internal tissue support close to the distal opening thereof, with which support the tissue that extends into the lumen of the trocar can make contact under the influence of reduced pressure inside the trocar. This way, corresponding to US 8,603,031 , the tissue is held firmly in place in contact with the rigid and firmly fixed tissue support. In this device the tissue support has a passage way for a cutting member. This cutting member can have all kinds of different spatial

configurations and ways of movement to provide for different kinds of cuts in different types of tissues.

US 2005/0261673 also discloses a device for making a cut in a tissue. This device is a tubular suction tool for accessing any anatomic surface or space and in particular the pericardium and pericardial space. The device incorporates a suction cavity connected to a lumen for creating a decreased pressure in the cavity to form a bleb of tissue into the suction cavity. A cutting tool can be introduced in the tubular tool to make a cut in the tissue bleb. In order to increase the versatility of the device, a depth control to provide an adjustable cutting depth of the knife is provided for. This allows a surgeon to finely adjust the distance that the distal end of the cutting tool is advanced out of the lumen port into the tissue bleb. Also, the angle of the cutting tool with respect to the tissue bleb can be adjusted by having a deflection mechanism with which the angle between the wall of the cavity and the main tubular body can be varied. US 5,972,013 discloses a device for making a cut into a tissue, which device has a comparable set-up with the device as known from US 8,092,477. In this set-up however the tissue support functions both as a support for the tissue bleb drawn into the lumen as well as a deflector for the cutting element. US 2005/0070763 also discloses a device for making a cut into a tissue. In this device tissue is drawn via an opening into a lumen for making the cut. When not in use, the opening is closed using a flexible stop plate in its first configuration. This stop plate can be flexed into the lumen to take its second configuration and then act as a support for tissue drawn into the lumen. OBJECT OF THE INVENTION

It is an object of the invention to improve existing devices for making a cut in a tissue at a predetermined site, and in particular to increase the versatility of the device.

SUMMARY OF THE INVENTION In order to meet the object of the invention, a device as described in the "General Field of the Invention" section here above has been developed, wherein in the device, the tissue support is movable with respect to the elongated member in a direction transverse to the plane of the opening, in particular with respect to the distal end of the elongated member. In other words, the tissue support is movable to arrive at various predetermined positions within the device, wherein at each of these positions the tissue support is operative for supporting the tissue drawn into the lumen. This means that the position the tissue support can take in the lumen can be changed by changing the relative position of this support with respect to (the centre of) the elongated member. This way, the tissue support is adjustably positioned in the elongated member, i.e. the tissue support can take various fixed positions, each of the positions allowing a different cutting process (i.e. a process ultimately resulting in a different cut by varying for example the depth and length of the cut for example to accommodate different types of tissue and/or tissue with varying thickness). In other words, the invention provides that the position the gas permeable tissue support takes within the elongated member of the device is operatively adaptable. Thus, in the device, while being ready for surgical use (thus being in an operative configuration), the tissue support, by making a

corresponding adjustment, can be located at various predetermined positions within the device. At each of these positions the tissue support has a different distance with respect to the opening, but still, at each of these positions the tissue support is firmly fixed with respect to the opening, and thus the tissue support is operative for stabilising the tissue drawn into the lumen.

Applicant recognized that by providing the tissue support in an adjustable way in the device, the device is more versatile, since it may now be easier and more effective to adapt the device to a type of cut to be made without having to interfere with the set-up and/or movement of the cutting element as is known from the prior art. Also, with respect to adapting the shape of the cavity by having an inflatable member at the opening of the device (see US 8,603,031), which member can be inflated to various levels leading to various configurations (like a balloon that can be inflated from small to big configurations), the advantage is that the cavity retains its rigidity and thus its form, independent of the shape of the cavity and the forces exerted by tissue entering the cavity. This increases the surgical reliability of the device.

The inventions is also embodied in a method for making a cut in a tissue at a predetermined site, the method comprising taking a device as described here above, and before approaching the tissue to be cut, adjusting the distance between the tissue support and the opening by moving the tissue support with respect to the elongated member in a direction transverse to the plane of the opening, in particular to obtain a position of the support within the device that corresponds to the type of tissue and the cut to be made, approaching the tissue and positioning the device on the tissue wherein the opening of the device is located above the site, drawing at least part of the tissue into the lumen by providing a reduced pressure in the lumen, such that the tissue with the site is supported, typically by contact with the tissue support, and making the cut in the tissue at the predetermined site. In this method also, by using the device of the invention, the tissue support is movable with respect to the elongated member in a direction transverse to the plane of the opening to arrive at various predetermined positions within the device, wherein at each of these positions the tissue support is operative for supporting the tissue drawn into the lumen.

DEFINITONS

A vacuum pump is any means to reduce pressure by removing gas and optionally fluid from a confined space.

Adjustable is capable of being changed, while in an operative configuration, to suit particular needs.

A fulcrum is the point on which a lever rests or is supported and on which it pivots.

The proximal part of an elongated instrument is the part nearest to the site of (manually) handling the instrument.

The distal part of an elongated instrument, as opposed to the proximal part, is the part furthest away from the site of handling the instrument. The distal part is also referred to as the downstream part.

Adjacent means near or nearby.

Automatically means without the need of operator intervention, although it is not excluded that the action is operator initiated or stopped.

A guide wire is a thin, usually flexible wire that can be inserted into a confined or tortuous space to act for example as a guide for subsequent insertion of a stiffer or bulkier instrument or prosthesis, such as a catheter or intramedullary pin.

EMBODIMENTS OF THE INVENTION In a first embodiment of the device according to the invention, the position of the tissue support within the elongated member is continuously variable. Although of course the total range of movement for the tissue support is inherently restricted, in this

embodiment, within the allowed range, the support can take any position. In the art, notches or other discontinuities are described for various adjustments, but by having the option of a continuous movability and fixation at a predetermined positon, the versatility of the device is further increased.

In another embodiment of the device according to the invention, the cutting element has an adjustable cutting depth with respect to the tissue support. In this embodiment also the cutting element may have an adjustable cutting depth. This further increases the versatility of the device. An advantage over the prior art devices with such an adjustable cutting depth is that by having the tissue support at an adjustable position, the adjustability of the knife need not be as big in order to obtain the same variability in cutting.

In again another embodiment of the device according to the invention, the cutting element is a blade that is arranged rotatably in the lumen around a fulcrum. Such a cutting element has been found of particular use for making fine cuts, for example in the pericardium to reach the pericardial space. In a further embodiment the fulcrum is located proximal of the tissue support. This fulcrum may have an adjustable position with respect to the tissue support in order to further increase the versatility of the device.

In yet another embodiment of the device according to the invention the opening coincides with the distal end of the elongated member and extends radially with respect to the longitudinal direction of the member. In this embodiment the device has a

"vertical" set up such as known for example from US 8,092,477 and US 5,972,013. In this embodiment, if the free space around the tissue is large enough, positioning of the opening over the predetermined site to be cut is relatively easy. In a further embodiment the elongated member comprises a proximal sub-member in operative connection with a distal sub-member, wherein the distal sub-member can be repositioned in the longitudinal direction with respect to the proximal member. In this further embodiment the elongated member can be made longer and shorter by moving the two sub- members with respect to each other. Various mechanical means can be used for this, the most simply one is by using one member as a screw that is rotated with respect to the other that is used as a corresponding bolt. By making the elongated member longer or shorter, the opening is repositioned more distally from or proximally to the proximal sub-member. If the tissue support has a fixed position with respect to the proximal member for example, this effectively means that the tissue support is moved away from or towards the opening of the device respectively. In still a further embodiment the tissue support is part of an intermediate sub-member that has an adjustable position both with respect to the proximal sub-member and the distal sub-member. This may increase the easy of moving and/or possibilities of varying the position of the tissue support within the elongated member.

In an alternative embodiment to the previous embodiments, the opening is adjacent the distal end of the elongated member and extends axially with respect to the member. This "horizontal" set-up, corresponds to the set-up of a device such as known from US 8,603,031. This set-up is advantageous for use in confined spaces such as when trying to reach the heart underneath the ribs/sternum for making a cut in the pericardium. In this embodiment the position of the tissue support in the elongated member is adjustable in a radical direction of this member. In yet another embodiment of the device according to the invention, the elongated member is provided with a guide wire tube having a distal end in proximity of a cutting tip of the cutting element. This specific improvement is also embodied in a method according to the invention, in which method a guide wire is automatically inserted through the guide wire tube into the cut of the tissue after the cut has been made.

The invention will now be explained in more detail using the following examples.

EXAMPLES

Figure 1 schematically shows a device according to the invention in a vertical set-up. Figure 2 schematically shows some details at the distal end of the device according to figure 1.

Figure 3 schematically shows internal details of the device according to figure 1.

Figure 4 schematically shows a guide wire application using a device according to the invention.

Figure 5 schematically shows a device according to the invention in a horizontal set-up.

Figure 1

Figure 1 schematically shows a device 1 according to the invention in a vertical set-up. The device 1 comprises as its basic member an elongated tube that consists of a proximal member 2 and a distal member 20 (which could also be cut of slantwise, for example having an angle between 0 and 45°), which latter member can be repositioned with respect to the proximal member (see figure 3 for more details). In this embodiment, the elongated member is in fact a hollow cylindrical tube having a large internal lumen. At the proximal end a handle 3 is added to allow easy manipulation by hand. At the distal end the member has an opening that connects the exterior of this member to the lumen. Although there is a tissue support member 6 at the border between the sub- members 2 and 20, this member is gas-permeable so that the distal opening of the elongated member is indeed connected to the whole of the lumen. The tissue support 6, together with the side wall of the elongated member at its distal end (in this case formed by member 20) form a cavity to be used for providing a stabilised tissue bleb during use of the device as will explained here beneath. The depth of the cavity can be varied since the tissue support 6 is movable with respect to the elongated member in a direction transverse to the plane of the opening. In this particular embodiment wherein the tissue support is fixed with respect to sub-member 2, the movement comes about by having sub-member 20 in an arrangement wherein it can be repositioned with respect to sub- member 2 in the axial direction. In this embodiment the sub-members have a connection wherein the sub-member 20 has internal screw thread that fits external screw thread on sub-member 2. This way, sub-member 20 can be positioned to and away from sub-member 2. The net effect of repositioning the sub-member 20 while keeping the tissue member fixed with respect to the sub-member 2, is that the tissue member is moved with respect to the elongated member, in particular with respect to its distal end. This way, the depth of the cavity can be controlled very precisely. The device is foreseen with a cutting blade 8 that is pivoted around fulcrum 7, which fulcrum is fixed with respect to the proximal sub-member 2. The blade can make a cutting movement by making one or more swings like a pendulum. Sub-member 2 is provided with a connector 4 for operatively connecting the lumen to a vacuum pump (not shown) via tubing 5, by virtue of which the pressure in the lumen can be reduced.

During a surgical procedure, depending on the type of tissue to be cut, and the depth and type of the cut to be made, firstly the distance between the tissue support 6 and the distal opening is adjusted by moving the tissue support with respect to the elongated member in a direction transverse to the plane of the opening as explained here above. Thereafter, the tissue is approached and the device is positioned on the tissue such that the opening of the device is located above the site to be cut. Then, at least part of the tissue is drawn into the cavity 10 by providing a reduced pressure in the lumen, such that ultimately the tissue with the site is supported in the cavity. Then, a cut is made in the tissue by forcing the blade 8 to make one swing through the tissue. After that the device can be removed for allowing access to the tissue and cut, or the device can be left in place to be used as a cannula for further surgical operations, for example to insert a guide wire into the tissue via the cut, or any other laparoscopic procedure.

Figure 2

Figure 2 schematically shows some details at the distal end of the device according to figure 1. In this angle of view, the internal screw thread 21 of sub-member 20 can be seen. Also, a slit 62 in the tissue support 6 is visible. This slit is needed to allow for the cutting blade 8 to make a swinging movement. The slit has a wider portion near one side to allow a guide wire to be inserted into the tissue via the tissue support 6. In order to make sure the tissue support has a sufficient gas permeability, openings 62 are provided in this support.

Figure 3

Figure 3, divided in sub-figures 3A, 3B, 3C and 3D, schematically shows internal details of the device according to figure 1. In this schematic view, in each sub-figure the distal part of proximal sub-member 2, next to sub-member 20 (as a whole) are depicted. In this embodiment the tissue support 6' is part of an intermediate cup-shaped member 60 that is located at the intersection of sub-members 2 and 20. This cup-shaped member 60 can be repositioned with respect to sub-member 2 as well as with respect to sub- member 20. The blade 8 has a position which is fixed with respect to sub-member 2. The four sub-figures each represent a different configuration wherein the tissue support has different positions with respect to the elongated member (in particular with respect to the distal opening thereof) and wherein the blade has different positions with respect to the tissue support 6.

In figure 3A, the sub-member 20 has an intermediate position with respect to sub- member 2, such that the cavity 10 has an intermediate depth. Tissue support 6 is located at a position where it is contiguous with the distal end of proximal sub-member 2. This provides a maximum cutting depth for the blade 8. In figure 3B, the sub-member 20 is at an inward position to arrive at a cavity 10 of only a very small depth. The tissue support 6 is located very near to the distal opening of the device. By having the tissue support positioned away from sub-member 2, the cutting depth of the blade 8 is minimal. Figure 3C represents a case wherein the cavity has its maximal depth, and also the cutting blade is positioned to have a maximum cutting depth. Figure 3D represents a configuration of a maximum cavity depth and minimal cutting depth.

Figure 4

Figure 4, divided in sub-figures 4A and 4B, schematically shows a guide wire application using a device according to the invention. In figure 4A the situation is depicted wherein a tissue bleb is drawn into the cavity and the cutting blade 8 is on the verge of making a cut in the tissue. In this embodiment, the blade is formed integrally with a guide wire tube 9 through which tube a guide wire can be advanced in the direction of the arrow is indicated. In figure 4B the cut has been made and immediately after that, while the tissue is still open, the guide wire 12 is automatically advanced through the tube into the tissue via the cut. By having the tube opening situated adjacent the blade tip, this opening is situated below the cut tissue when the cut is made. This way, the guide wire will not be hindered by any tissue while being advanced out of the tube. It was recognised that it is advantageous to have the guide wire automatically advanced immediately after the cut has been made. This is since immediately after the cut, the tissue "halves" (borders of the cut) are in an open positon but they will close soon after that by elastic forces in the tissue. Since this process takes only very little time, it is advantageous not to await an action by the surgeon to advance the guide wire, but to implement this as an automatic action as soon as the full cut has been completed.

Figure 5

Figure 5 schematically shows a device according to the invention in a horizontal set-up. In this set-up the device has a one-piece elongated member 2 that has an opening adjacent its distal end, which opening extends axially with respect to the longitudinal direction of the member. In the opening a ring shaped member 30 with internal screw thread is provided, which member firmly fixes the tissue support 6 at a predetermined position. This position can be continuously varied by screwing the tissue support in or out in radical direction. This way, the depth of the cavity can be continuously varied. The cutting device is not shown in this schematic view.

Claims

1. A device (1) for making a cut in a tissue at a predetermined site, the device comprising:

- an elongated member (2, 20) having a lumen,

- the member having an opening (11) that connects the exterior of the member to the lumen, wherein the opening is to be positioned over the tissue at the site,

- a connector (4) for operatively connecting the lumen to a vacuum pump for reducing the pressure in the lumen in order to draw at least part of the tissue including the site into the lumen,

- a gas permeable tissue support (6) located in the lumen adjacent the opening, towards which support the at least part of the tissue is drawn under the reduced pressure,

- a cutting element (8) located in the elongated member for cutting the tissue drawn into this member at the said site, characterised in that in the device, the tissue support is movable with respect to the elongated member in a direction transverse to the plane of the opening.

2. A device according to claim 1 , characterised in that the position of the tissue support within the elongated member is continuously variable.

3. A device according to any of the preceding claims, characterised in that the cutting element has an adjustable cutting depth with respect to the tissue support.

4. A device according to any of the preceding claims, characterised in that the cutting element is a blade that is arranged rotatably in the lumen around a fulcrum (7).

5. A device according to claim 4, characterised in that the fulcrum is located proximal of the tissue support.

6. A device according to claim 5, characterised in that the fulcrum has an adjustable position with respect to the tissue support.

7. A device according to any of the preceding claims, characterised in that the opening coincides with the distal end of the elongated member and extends radially with respect to the longitudinal direction of the member.

8. A device according to claim 7, characterised in that the elongated member comprises a proximal sub-member (2) in operative connection with a distal sub-member (20), wherein the distal sub-member can be repositioned in the longitudinal direction with respect to the proximal member.

9. A device according to claim 8, characterised in that the tissue support is part of an intermediate sub-member (60) that has an adjustable position both with respect to the proximal sub-member and the distal sub-member.

10. A device according to any of the claims 1 to 6, characterised in that the opening is adjacent the distal end of the elongated member and extends axially with respect to the member.

1 1. A device according to any of the preceding claims, characterised in that the elongated member is provided with a guide wire tube (9) having a distal end in proximity of a cutting tip of the cutting element.

12. A method for making a cut in a tissue at a predetermined site comprising:

- taking a device according to any of the preceding claims 1-1 1 ,

- adjusting the distance between the tissue support and the opening by moving the tissue support with respect to the elongated member in a direction transverse to the plane of the opening,

- approaching the tissue and positioning the device on the tissue wherein the opening of the device is located above the site,

- drawing at least part of the tissue into the lumen by providing a reduced pressure in the lumen, such that the tissue with the site is supported,

- making the cut in the tissue at the predetermined site.

13. A method according to claim 12, in which method a device according to claim 1 1 is used, characterised in that a guide wire (12) is automatically inserted through the guide wire tube into the cut of the tissue after the cut has been made.