GB2554375A

GB2554375A - Device

Info

Publication number: GB2554375A
Application number: GB1616165.5A
Authority: GB
Inventors: Laasch Hans-Ulrich
Original assignee: Snakebite Medical Ltd
Current assignee: Snakebite Medical Ltd
Priority date: 2016-09-22
Filing date: 2016-09-22
Publication date: 2018-04-04
Also published as: GB201616165D0

Abstract

A device (1) for accessing a location within a body lumen and obtaining a biopsy sample, the device (1) comprising: first (2) and second (4) elongate members; a first cutter part (8) connected to the first elongate member (2); and a second cutter (12) part connected to the second elongate member (4); wherein the first (2) and second (4) elongate members are moveable relative to one another and configured to move at least one of the first (8) and second (12) cutter parts in a longitudinal direction of at least one of the elongate members between an open position and a cutter interaction position for cutting a biopsy sample. The first member (2) may comprise a dilation element (10). The device may comprise a chamber (16) for holding the tissue sample, possibly located within an outer sheath of the second member (4). A portion of the chamber may be defined by the first member, such as between the dilation element (10) and the cutter part (8). Said cutter parts may be electrically connectable to a source of electrical current, such as a radio frequency alternating current, and may comprise a radiopaque material. The device may comprise a grip at the proximal end. Said grip may comprise first and second grip elements (32 & 34, fig.4) connected to the first and second elongate members respectively, may permit single-handed use of the grip and may comprise gradations to provide an indication of the distances between the two cutter parts. The device may be adapted to move over a guide wire (6).

Description

(54) Title of the Invention: Device

Abstract Title: Device for Obtaining a Biopsy Sample from within a Body Lumen (57) A device (1) for accessing a location within a body lumen and obtaining a biopsy sample, the device (1) comprising: first (2) and second (4) elongate members; a first cutter part (8) connected to the first elongate member (2); and a second cutter (12) part connected to the second elongate member (4); wherein the first (2) and second (4) elongate members are moveable relative to one another and configured to move at least one of the first (8) and second (12) cutter parts in a longitudinal direction of at least one of the elongate members between an open position and a cutter interaction position for cutting a biopsy sample. The first member (2) may comprise a dilation element (10). The device may comprise a chamber (16) for holding the tissue sample, possibly located within an outer sheath of the second member (4). A portion of the chamber may be defined by the first member, such as between the dilation element (10) and the cutter part (8). Said cutter parts may be electrically connectable to a source of electrical current, such as a radio frequency alternating current, and may comprise a radiopaque material. The device may comprise a grip at the proximal end. Said grip may comprise first and second grip elements (32 & 34, fig.4) connected to the first and second elongate members respectively, may permit single-handed use of the grip and may comprise gradations to provide an indication of the distances between the two cutter parts. The device may be adapted to move over a guide wire (6).

(Obc, It. /, lot

Fig. 4

Device

The present invention relates to a medical device, in particular but not exclusively, it relates to a device for accessing a location within a human or animal body lumen such as the bile duct, pancreatic duct, ureter or other small tubular structures and obtaining a biopsy sample.

Tumours of cancerous and non-cancerous origin can lead to an abnormal narrowing or stricture of a passageway (lumen) within the body which results in further complications for a patient. For example, cholangiocarcinoma or bile duct cancer can lead to a bile duct stricture which can obstruct the drainage of bile into the small intestine. Pancreatic head cancer may lead to a stricture of both the pancreatic duct and bile duct respectively obstructing the supply of pancreatic juices and bile. This can result in jaundice, pancreatitis and other complications.

Ameliorating the effects of these strictures generally involves some form of medical intervention to reopen the stricture, for example, by the insertion of a stent. However, it is also necessary to diagnose and treat the underlying cause of the stricture, i.e. the cancer. Accurate diagnosis of the cancer generally requires accessing the site of interest and obtaining a tissue sample from the tumour. However, body lumina can be difficult to access.

A number of techniques for accessing body lumina have been devised. For example, endoscopic retrograde cholangiopancreatography (ERCP) is a technique which can be used to diagnose and treat conditions relating to the bile and pancreatic ducts. This involves inserting an endoscope through the mouth, down the oesophagus, through the stomach and into the duodenum to the location of the ampulla of Vater, i.e. the point where the common bile duct and pancreatic duct join and drain into the duodenum. Whilst the ampulla is being directly observed with the endoscope, a catheter can be delivered to the site via a working channel in the endoscope. The catheter is inserted into the ampulla and a radiopaque dye is injected via the catheter into the bile and/or pancreatic ducts. Fluoroscopy can then be used to look for a tumour related stricture in the ducts. If a tumour is identified, the endoscopic operator can attempt to obtain a tissue sample and a number of techniques for doing this are discussed below.

Once the endoscope is in place, i.e. at a location where the site or lumen of interest can be observed, a working channel in the endoscope can also be used to deliver other instruments. For example, a guide-wire can be inserted into the lumen and through the stricture using fluoroscopy. A stent delivery system can then be moved over the guide-wire to the site of the stricture and a stent inserted to reopen the lumen.

Another technique is to access the body lumen percutaneously, i.e. through the skin (percutaneous transhepatic choiangiogram, PTC). For example, the common bile duct can be accessed percutaneously by inserting an introducer sheath through the side of a patient's abdomen, penetrating the liver and entering one of the hepatic bile ducts which feed into the common bile duct. Catheters and guide-wires of increasing size can then be introduced via the introducer sheath and guided to the site of interest in the common bile duct using fluoroscopy until access to the common bile duct has been obtained. Fluoroscopy or ultrasound can also be used to identify strictures. Once a suitably sized guide catheter has been delivered to the site of interest, other instruments can be delivered via the guide catheter to obtain tissues samples and/or deliver a stent.

There are a number of methods of obtaining a tissue sample from the tumour. The most common method involves using a cytology brush, which is a collection of bristles arranged at the end of a long flexible member. The brush may have a metal tip for visibility under fluoroscopy. Cytology brushes can either be moved to the site of interest over a guide-wire or through a catheter. The brush is brushed against the tumour in the hope that cells from the tumour will be caught between the bristles of the brush. The brush is then removed from the patient and the ceils collected so that they can then undergo cytopathology tests, i.e, examination of the cells under a microscope for signs of cancerous abnormalities.

A problem with cytology brushes is that it is often difficult to obtain a sufficient yield of cells for achieving satisfactory cytopathology results because the brush bristles may not be stiff enough to remove many cells or the cells may become dislodged from the bristles as the brush is removed. If only a few cells are removed, there may not be sufficient number to diagnose the cancer. A further problem with cytology brushes is that they can be difficult to control to bring them suitably firmly into contact with the tumour. This is particularly the case if the duct or lumen undergoing investigation or treatment is oriented at an awkward angle relative to the catheter or endoscope used to deliver the brush. For example, in cases in where the working channel of an endoscope is used to deliver the cytology brush to the bile duct, the bile duct is oriented substantially at 180 degrees to the direction in which the endoscope is introduced info the duodenum such that the flexible member of the brush has to double back on itself, A consequence of these problems is that the patient will have undergone a significant invasive procedure for possibly no or limited benefit and the procedure may need to be repeated.

A further limitation is that some tumour types, such as lymphoma, require coherent tissue samples demonstrating the architecture of the tumour in order to allow an accurate histological diagnosis. Brush cytology is inadequate in such cases.

Another method of obtaining a tissue sample is to take a biopsy of the tumour, i.e. to remove of a small piece of the tumour tissue. This provides a larger tissue sample compared to the cells obtained by the cytology brush, which can then undergo histopathology tests, i.e. taking a thin section of the sample and examining it under a microscope for signs of cancerous abnormalities.

A conventional means of obtaining a biopsy sample from a body lumen which has been accessed via one of the techniques described above is to use a single-use biopsy forceps. This comprises a pair of cutting scoops hingedly mounted at the distal end of a long thin flexible member such that the scoops can be pivotally moved between an open and closed position. A spike is arranged at the distal end of the forceps and is protected by the scoops when they are in the closed position. A grip at the proximal end of the flexible member and inner control wire can be used to open and close the scoops. The biopsy forceps can be delivered with the scoops in the closed position to the site of interest via the working channel of an endoscope or percutaneously via a catheter. To obtain a sample the scoops are opened to expose the spike which is then jabbed or quickly pushed into the tumour to hold the distal end of the forceps in place whilst the scoops are closed. The action of closing the scoops cuts out a small piece of the tumour. The forceps can then be removed from the patient and the sample collected for analysis.

In this document, the “distal” and “proximal” directions are relative to the device’s intended insertion point into the body. Therefore, a distal portion of the device will be closer to the site of interest within the patient’s body after insertion of the device, whereas a proximal portion will be closer to the operator.

A problem with biopsy forceps is that, like cytology brushes, they can be difficult to control particularly if the duct or lumen undergoing investigation or treatment is oriented at an awkward angle relative to the catheter or endoscope used to deliver the forceps. For example, in cases in where the working channel of an endoscope is used to deliver the biopsy forceps to the bile duct, the bile duct is oriented substantially at 180 degrees to the direction in which the endoscope is introduced into the duodenum such that the flexible member of the forceps has to double back on itself. With this technique there is an increased risk of injury or perforation of the bile duct. Another problem is that accurate placement of the cutting scoops can be difficult. Although the metal cutting scoops of the forceps are easily visible under fluoroscopy, as described above the spike needs to be jabbed or quickly pushed into the tumour, which means that the final stage of delivering the forceps to the tumour involves a swift jabbing action which reduces the accuracy of placement of the forceps and ultimately the sample obtained. Whilst more accurate placement can be achieved by guiding instruments to the site of interest with a guide-wire, there are currently no over-the-wire histological devices in existence of which the inventor is aware. Furthermore, biopsy forceps can cause relatively significant trauma to the site they are sampling, particularly when it is considered that the lumen in question may be small and delicate. This increases the risk of such a procedure to the patient.

Aspects and embodiments of the invention were devised with the foregoing in mind.

Viewed from a first aspect, the present invention provides a device for accessing a location within a body lumen and obtaining a biopsy sample, the device comprising: first and second elongate members; a first cutter part connected to the first elongate member; and a second cutter part connected to the second elongate member; wherein the first and second elongate members are moveable relative to one another and configured to move at least one of the first and second cutter parts in a longitudinal direction of at least one of the first and second elongate members between an open position and a cutter interaction position with the other of the first and second cutter parts for cutting a biopsy sample. That is to say, just the first cutter part may be moved to the cutter interaction position or just the second cutter part may be moved to the cutter interaction position or both the first and second cutter parts may be moved to the cutter interaction position.

Such a device may assist in obtaining a better yield of tissue compared to known techniques, in particular cytology brushes. It can also be used with existing access techniques, for example, through an endoscope as is the case in ERCP or percutaneously. There is also the option to use the device to perform a biopsy prior to stent insertion as part of the same invasive procedure without the need for additional equipment or specialised apparatus. This reduces the number of procedures a patient has to undergo. Furthermore, taking a biopsy from the tumour at the site of the stricture assists in removing some of the blockage and opens up the stricture. Moreover, the device provides for accurate placement across the stricture and is simple to use, i.e. it requires the same or similar control and manual dexterity to the placement of a stent. This obviates the need for specialist training. In addition, the device is relatively simple and cost-effective to manufacture.

Typically, at least one of the first and second cutter parts has a sharp edge. This improves ease of cutting.

Optionally, the first and second cutter parts may have opposing sharp edges. This improves the cutting action.

Optionally, the first and second cutter parts may overlap in the closed position. This assists in completely severing the biopsy sample from the tumour and avoids a tearing of the tumour or body lumen.

Typically, the cutter parts may be of a circular or oval shaped cross-section for conformity with the inner profile of a body lumen. The first and second cutter parts may respectively comprise first and second cutter rings. Rings conform more closely to the inner profile of body lumens and increase the available cutting length. Alternatively, at least one of the cutter parts may have another geometric configuration.

The first elongate member may comprise a dilation element at its distal end. This assists in opening up a stricture and allowing the device to pass through the previously constricted region.

Optionally, the first cutter part may be located at a proximal end of the dilation element. The second cutter part may be located at a distal end of the second elongate member.

Optionally, the cutter parts may comprise a radiopaque material. This assists with accurate placement of the device across a stricture as the cutter parts are clearly visible under fluoroscopy.

The cutter parts may comprise stainless steel. Stainless steel is a radiopaque and biocompafible material.

Optionally, the cutter parts may be arranged perpendicular to the main or long axis of the elongate members or arranged at an angle to the main or long axis of the elongate members.

Optionally, the device may further comprise a chamber for holding the biopsy sample. The chamber may securely contain the sample until the device has been remove from the body.

The first elongate member may comprise an inner member and the second elongate member comprise an outer sheath arranged outside the inner member. Such an arrangement is compact and permits relative movement of the first and second elongate members with respect to each other.

Optionally, at least a portion of the chamber may be located within the outer sheath. This keeps the profile of the chamber within the profile of the outer sheath and helps provide a streamlined design thereby assisting with movement of the device through a body lumen.

The chamber may be defined at least in part by the inner wall of a portion of the outer sheath proximal of the second cutting part. This helps capture the sample as it is being cut.

Optionally, the first elongate member may comprise at least another portion of the chamber. This provides another arrangement for the chamber.

The at least another portion of the chamber may be located between the dilatation element and the first cutter part. This helps capture the sample as it is being cut.

Optionally, the inner member may comprise an inner sheath adapted to move over a guidewire. This allows the device to be used with conventional guide-wire access techniques and assists with accurate placement of the device.

A grip may be located at a proximal end of the device. This assists manual control of the device.

Optionally, the grip may comprise first and second grip elements connected to the first and second elongate members respectively and may be configured to allow a user to control relative movement of the first and second elongate members. The first and second grip elements may comprise finger engagement structures to permit single-handed use of the grip.

The grip may comprise a connector in fluid communication with the chamber to which a suction device can be connected to apply suction to the chamber. This increases the likelihood of capturing biopsy tissue within the chamber during use.

Optionally, the grip may have a plurality of graduations which provide an indication of a distance between the first and second cutter parts. This allows an operator to determine how far the cutter parts are spaced apart.

The cutter parts may be electrically connectable to an electric current source. In use, the cutter parts may be coupled to the electric current source and the electric current can be used to heat the cutter parts to provide for coagulation of tumour tissue, for example, for the purpose of haemostasis (to cause bleeding from the biopsied tumour to stop) or local tumour destruction by thermal ablation.

Viewed from a second aspect, the present invention provides a device for accessing a location within a body lumen and obtaining a biopsy sample, the device comprising at least one cutter part, wherein the cutter part is electrically connectable to an electric current source, in use, the at least one cutter part may be used to cut a biopsy sample and the electric current can be used to heat the at least one cutter part to provide for coagulation of tumour tissue, for example, for the purpose of haemostasis or local tumour destruction by thermal ablation.

The electric current source may comprise a high frequency alternating current source, and optionally a radio frequency or microwave frequency alternating current source. An electric current alternating at radio frequency has been found to be particularly effective at heating the cutter parts.

Optionally, the device may further comprise an opening along its length through which a guide-wire can be passed, the opening providing communication between an exterior of the device and an inner guide-wire channel.

The above and other embodiments in accordance with aspects of the present invention will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Figure 1 is a part cross-sectional view of a distal part of a device in accordance with an embodiment of the present invention being guided by a guide-wire.

Figure 2 is a cross-sectional view of part of a body lumen having a tumorous stricture showing the device of Figure 1 in the open position located across the stricture.

Figure 3 shows the body lumen of Figure 2 with the device of Figure 1 in a closed or cutter interaction position having removed a tissue sample from the tumour.

Figure 4 is a plan view of a proximal part of a device in accordance with an embodiment of 5 the present invention showing a grip element of the device.

Referring to Figure 1, there is shown a distal end of a device 1 for accessing a location within a body lumen and obtaining a biopsy sample. The device 1 comprises a first elongate member 2 and a second elongate member 4. The second elongate member 4 is tubular in form and surrounds the first elongate member 2. The second elongate member 4 therefore constitutes an outer member or outer sheath. The first elongate member 2 is also tubular in form and has an opening at each of it ends so that the Interior of the tube can receive and move over a guide-wire 6 to the site of interest within the body lumen. The first elongate member 2 therefore constitutes an inner member or inner sheath.

The first 2 and second 4 elongate members are used fo access the body lumen of interest. Access can be obtained either percutaneously or via an endoscopic technique such as ERCP, cystoscopy or colonoscopy. The first 2 and second 4 elongate members are relatively long compared to their width or diameter, with their length depending on the location of the body lumen. For example, to access a lumen in the region of a patient’s intestine via ERGP, the elongate members 2, 4 may have a length of over 2 metres. The outer width or diameter of the second elongate member 4 is relatively thin compared to its length, e.g. between 2 and 5 mm, in order to make the device flexible and allow it to navigate through relatively small body lumens. The thinness of the device 1 reduces the size of incision which needs to be made in a patient’s abdomen if the lumen of interest is accessed percutaneously and also allows the device 1 to be delivered to the lumen of interest via the working channel of an endoscope. However, the ordinarily skilled person will appreciate that different lengths or diameters may be used depending on the lumen and its location in the body.

The first 2 and second 4 elongate members are moveable relative to one another in a longitudinal direction, i.e. the second elongate member 4 can move over the first elongate member 2 and the first elongate member 2 can move within the second elongate member 4 in a direction along the lengths of either the first 2 or second 4 elongate members.

A first cutter part 8 for cutting a tissue sample is connected to the first elongate member 2 via a dilation element 10, which is a tapered, bulbous or conical component arranged at the distal end of the device for assisting in moving the device through the body lumen by dilating any narrowing or stricture in the lumen to allow the device to pass through them. In the art, such dilation elements are commonly referred to as ‘olive tips”. The first cutter part 8 is located at a proximal end of the dilation element 10 and comprises a cutter ring arranged around the outer diameter of the dilation element 10.

A second cutter part 12 for cutting a tissue sample is located at a distal end of the second elongate member 4 and also comprises a cutter ring arranged around the outer diameter of the second elongate element 4, The first 8 and second 12 cutter parts have opposing sharp edges 8a and 12a respectively. Sharp edge 8a is located at a proximal edge of the first cutter part 8a and sharp edge 12a is located at a distal edge of the second cutter part 12a. By moving the first 2 and second 4 elongate parts relative to one another, the cutter parts 8 and 12 can be moved between a closed or cutter interaction position in which the cutter parts 8 and 12 interact to cut a biopsy sample and an open position in which the cutter part 8 and 12 are spaced apart. Figure 1 shows the cutter parts 8 and 12 in the closed or cutter interaction position.

In the closed or cutter interaction position, the cutter parts 8 and 12 or the respective sharp edges 8a and 12a of the cutter parts 8 and 12 overlap, touch or interlock. The outer diameter of the first cutter part 8 is slightly larger than the outer diameter of the second cutter part 12 so that a portion of the second cutter part 12 fits or nests within the first cutter part 8. However, the ordinarily skilled person will appreciate that such overlapping, touching or interlocking interaction can be achieved by other arrangements. For example, the outer diameter of the second cutter part 12 could be slightly larger than the outer diameter of the first cutter part 8 or the first 8 and second 12 cutter parts could have sharp edges with complementary angled blades which fit together. The overlapping engagement assists in cutting off a tissue sample by completely severing the sample from the tumour. This avoids the need to use a tearing action to remove the tissue.

The first 8 and second 12 cutter parts are made from stainless steel although other medical grade materials may be used. An advantage of using metals is that they are radiopaque and clearly visible under fluoroscopy, which assists in accurate placement of the device across a stricture. The first 2 and second 4 elongate members are made from medical grade polymers. They may be reinforced with wire mesh or windings to prevent them kinking as they are moved through various body lumens. In addition the first 2 and second 4 elongate members may be given a lubricious coating to assist them move along body lumens or to help with their relative movement. The first 8 and second 12 cutter parts may be attached to the dilation element 10 and the second elongate member 4 respectively using conventional methods, for example, by thermally bonding them to the device or using a biocompatible adhesive. However, the ordinarily skilled person will appreciate that other methods of attachment may be used.

The device 1 also comprises a guide member 14 which is located within the second elongate member 4 and proximally spaced from the distal end of the second elongate member 4. The guide member 14 is tubular in form and comprises an end face 14a at its distal end having a central aperture 14b through which the first elongate member 2 extends. The guide member 14 keeps the first elongate member 2 concentrically disposed within the second elongate member 4 at the distal end of the device in order to keep the first 8 and second 12 cutter parts aligned when being moved from the open position to the closed or cutter interaction position in order to achieve overlapping, touching or interlocking engagement of the cutter parts 8 and 12.

A chamber 16 for holding a biopsy sample is located within the second elongate member 4 between the distal end of the second elongate member 4 and the end face 14a of the guide member. The chamber 16 is defined by the inner wall of the distal end of the second elongate member 4 and the end face 14a. As discussed above, the second elongate member 4 has a tubular form and has an opening 17 at its distal end, which opening 17 is defined by the second cutter part 12, which is attached to the distal end of the second elongate member 4 and is formed as a cutter ring arranged around the outer diameter of the second elongate element 4. The opening 17 can be closed by the first cutter part 8 and dilation element 10 when the first 8 and second 12 cutter parts are in the closed or cutter interaction position.

When the first 8 and second 12 cutter parts are in the open position the chamber 16 is open and can receive a tissue sample through the opening 17. As the chamber 16 is immediately proximal of the second cutter part 12, the tissue sample is received in the chamber as it is cut from the tumour, which reduces the likelihood of the sample being lost. When the first 8 and second 12 cutter parts are in the closed or cutter interaction position, the chamber 16 is closed and can hold the tissue sample securely until the device is removed from a patient’s body.

Use of the device will now be described with reference to Figures 2 and 3.

Figure 2 shows a part of a body lumen 102 in cross-section. The lumen 102 has lumen wails 104 and a tumour 106 growing within and protruding from the lumen walls 104 which has caused a stricture or narrowing 105 within the lumen 102, The device 1 has been positioned across the stricture 105 with the first 8 and second 12 cutter parts in the open position.

To position the device 1 across the stricture 105 a guide-wire 6 is first guided to and through the site of the stricture. This can be done using conventional medical techniques such as the percutaneous or ERGP techniques described above. Once the guide-wire 6 is in place, the device 1 is fed over the guide-wire until the cutter parts 8, 12 are in the region of the stricture 105. The first 8 and second 12 cutter parts show up clearly under fluoroscopy and can be used to accurately place the first 8 and second 12 cutter parts across the stricture.

The device is delivered to the stricture 105 with the first 8 and second 12 cutter parts in the closed position to prevent the cutter parts 8, 12 snagging on objects along the way. Once the dilation element 10 reaches the stricture 105, it is pushed through the stricture 105 until both cutter parts 8, 12 are located just distally of the tumour 106. The first 8 and second 12 cutter parts are then moved to the open position by distally moving or withdrawing the second elongate member 4, i.e. in the direction of arrow A in Figure 2, until the second cutter part 12 is just proximal of the tumour 106 as illustrated in Figure 2. Fluoroscopy is used to ensure the first 8 and second 12 cutter parts are accurately located on either side of the tumour.

Once the first 8 and second 12 cutter parts are accurately placed, the next step is to move the first 8 and second 12 cutter parts to the closed or cutter interaction position, as shown in Figure 3. This involves moving or advancing the second elongate member 4 in the distal direction, i.e. in the direction of arrow B in Figure 3. As the first 8 and second 12 cutter parts are closed a tissue or biopsy sample 106a is cut from the tumour 106. As the tissue sample 106a is cut from the tumour it is received in chamber 16 via opening 17. When the first 8 and second 12 cutter parts reach the closed or cutter interaction position, the sample 106a has been completely severed from the tumour 106 and is trapped within the chamber 16. In particularly closed strictures in which the outer circumference of the device is in contact with the inner circumference of the stricture, the first 8 and second 12 cutter parts remove an annular tissue sample 106a from the tumour 106 due to their annular form. A significant yield of tissue is therefore obtained which provides a sample of tissue from the entire internal circumference of the stricture 105, improving the chances of diagnosing the type and cause of the tumour 106. Furthermore, as can be seen from Figure 3, the action of removing the annular tissue sample from the stricture removes some of the blockage and actually opens up the stricture 105, reducing the obstructive effect of the tumour 106.

Once the tissue sample 106a has been obtained, the device 1 can be removed from the patient’s body. The chamber 16 securely contains the sample 106a until the device 1 has been removed. The chamber 16 can then be opened by moving the first 8 and second 12 cutter parts to the open position to obtain the sample 106a, which can be sent for histopathology tests.

The above description is just one way of obtaining a tissue sample. The ordinarily skilled person will appreciate that the first 8 and second 12 cutter parts can be moved in a different order, i.e. the first 8 and second 12 cutter parts can be advanced in the closed position to just proximal of the tumour 106. Leaving the second cutter part 12 proximal of the tumour 106, the first elongate member 2 can then be advanced further in the distal direction, i.e. in the direction of arrow B in Figure 3 to push the dilation member 10 and first cutter part 8 through the stricture 105 until the first cutter part 8 is just distal of the tumour 106, The first 8 and second 12 cutter parts can then be closed by withdrawing the first elongate member 2 in the proximal direction, i.e. in the direction of arrow A in Figure 2, to obtain the sample.

Figure 4 shows a grip for controlling relative movement of the first 2 and second 4 elongate members which is located at a proximal end of the device 1. The grip comprises a first grip element 32 and a second grip element 34. The first grip element 32 is connected to the first elongate member 2 and controls movement of the first elongate member 2, The second grip element 34 is connected to the second elongate member 4 and controls movement of the second elongate member 4. The first 32 and second 34 grip elements can be moved away from or towards each other to control relative movement of the first 2 and second 4 elongate members.

The first 32 and second 34 grip elements have respective first 36 and second 38 locking parts which can be used to hold the first 2 and second 4 elongate members in place relative to another component. The first locking part 36 can be used to lock the first elongate member 2 relative to the guide-wire (not shown in Figure 4) and the second locking part 38 can be used to lock the second elongate member 4 relative to the first elongate member 2. The first 36 and second 34 locking parts comprise threaded locking components which can be locked via a right-hand screw action and unlocked via a left hand screw option. The first 32 and second 34 grip elements, or a proximal length of the first elongate member 2 which is visible when the first 32 and second 34 grip elements are spaced apart, may have graduations (not shown) indicating a distance between the first 8 and second 12 cutter parts. The first 32 and second 34 grip elements may have a window such that graduations on the first elongate member 2 are visible when the grip elements are in cooperative engagement.

A port or connector 40 extends from the outer surface of the second grip element 34 and has an inner channel (not shown) in fluid communication with the chamber 18. The port 40 may be a Luer-type port. A syringe can be attached to the port 40 in order to apply suction to the chamber 16 by creating a vacuum or partial vacuum in the chamber 16. This applies a suction force to the tissue sample and increases the likelihood of capturing biopsy tissue within the chamber 16 prior to closure of the first 8 and second 12 cutter parts. The central guide wire channel of the first elongate member 2 may be flushed for lubrication purposes by injecting a suitable fluid such as sterile saline through the first grip element 32 (not shown).

As used herein any reference to “one embodiment” or “an embodiment” means that a particular element, feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. The appearances of the phrase “in one embodiment” or the phrase “in an embodiment” in various places in the specification are not necessarily all referring to the same embodiment.

As used herein, the terms “comprises,” “comprising,” “includes, “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by any one of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

In addition, use of the “a” or “an” are employed to describe elements and components of the invention. This is done merely for convenience and to give a general sense of the invention. This description should be read to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

In view of the foregoing description it will be evident to a person skilled in the art that various modifications may be made within the scope of the invention.

For example, rather than an inner and outer tubular members, the skilled person will appreciate that the first and second elongate members could be other filamentary or elongate members, such as wires or lengths of polymer, and be arranged side by side with each connected to a separate cutter member. Such an arrangement could then be enclosed in a single sheath to assist with travel through the body. Furthermore, the first elongate member need not be tubular, particularly for applications in which the device is not fed over a guide-wire but through a catheter. Moreover, one of the cutter members may not have a sharp edge but could be an anvil or stop which would assist in cutting by acting as a surface against which the other cutter member can cut.

In addition, the first elongate member may comprise at least another portion of the chamber. For example, the another portion of the chamber could be located at the distal end of the device, i.e. between the dilation element and the first cutter part. The chamber could therefore be of a two-part design with part of the chamber being located in the second elongate member and part of the chamber being located and extending to a variable degree into the first elongate member. Alternatively, the chamber could be solely formed as part of the first elongate member.

Another modification may be to provide the grip with annular attachments or structures for insertion of an operator’s fingers. The annular attachments act as finger engagement structures which may allow single-handed use of the device.

A further modification may be to electrically connect the first and second cutter parts to a high frequency alternating electric current source and in particular a radio frequency alternating electric current source. The electricai connection can be made by means of electrical conductors arranged within the device, i.e. within the first and/or second elongate members. The electric current source is used to heat the cutter parts to provide for coagulation of tumour tissue, for example, for the purpose of haemostasis or local tumour destruction by thermal ablation. An electric current alternating at radio frequency has been found to be particularly effective at heating the cutter parts.

Modifications of the device also include providing the device with guide-wire ports or openings close to the distal tip of the system to create a rapid exchange system allowing the use of shorter guide-wires. A short wire system makes insertion and removal of the device of the present invention from a patient’s body easier and quicker and enhances exchange for another device such as a stent delivery system to the stricture of interest using the same short guide-wire as may have been used to deliver the device of the present invention.

A first guide-wire port or opening is provided in the second elongate member at a point along its length. The first guide-wire port passes through the tubular wall of the second elongate member providing communication between an exterior of the device and the interior of the second elongate member. Preferably, the first guide-wire port is in the region of its distal end, for example, proximal to the chamber. A second guide-wire port or opening is provided in the first elongate member in the same region as the first guide-wire port, i.e. in the region of the distal end of the first elongate member, for example, proximal to the chamber. The second guide-wire port passes through the tubular wall of the first elongate member providing communication between an exterior of the first elongate member and the interior of the first elongate member. The interior of the first elongate member between the second guide-wire port and the distal end of the first elongate member is configured to accommodate a guide-wire as in the above-described arrangements.

A ramp may extend from the tubular wall of the second elongate member inwardly from the first guide-wire port and into the second guide-wire port of the first elongate member. The ramp slopes inwardly towards the distal end of the device. The second guide-wire port is elongated or is formed as a slot such that it has a length which is greater than the length of the first guide-wire port. The ramp is able to move within the second guide-wire port. The length of the second guide-wire port is sufficient to allow for the longitudinal movement of the second elongate member relative to the first elongate member. Preferably, the second guide-wire port has a length sufficient to accommodate the cutting action of the cutter parts,

i.e. the length is greater than a maximum distance between the cutter parts when in the open position. This is to prevent jamming of the guide-wire between the first and second elongate members prior to the cutter parts reaching the open position.

In use, the guide-wire is fed through the distal opening of the first elongate member until it reaches the ramp. It travels up the ramp, passing through both the second-guide wire port and the first guide-wire port to an exterior of the device. Therefore, only a relatively short length of the guide-wire is located within the device, i.e. that part of the guide-wire located between the first guide-wire port and the distal opening of the first elongate member. The majority of the guide-wire is located outside the device. The device can be advanced to the site of interest with just this short length of guide-wire contained within the device. During use, the portion of the guide-wire located outside the device is always contained within the catheter or endoscope being used to deliver the device.

When withdrawing the device from a patient’s body, the guide-wire is left in place and the device is withdrawn until it disengages from the guide-wire. As a result of only a short length of the guide-wire is contained within the device, a considerably shorter guide-wire can be used. This is because the guide-wire only needs to extend this short length beyond the proximal end of the catheter or endoscope being used to deliver the device compared to having to extend the entire the length of the device, as would be the case in devices in which the guide-wire is advanced along the entire length of the first elongate member. Leaving the guide-wire in situ in the patient’s body also allows for rapid-exchange of devices because once the device of the present application has been removed another short-wire device can be immediately advanced to the site of interest using the same guide-wire.

Whilst the examples of body lumina discussed as background to this device have focussed on the bile and pancreatic ducts, the ordinarily skilled person would appreciate that the device can be configured to be used in other body lumina, such as the intestine or the genito-urinary tract by modifying the length or thickness of the device.

The device need not be restricted to the taking of biopsy samples but may be used to remove obstructive tissue or the like.

The scope of the present disclosure includes any novel feature or combination of features disclosed therein either explicitly or implicitly or any generalisation thereof irrespective of whether or not it relates to the claimed invention or mitigate against any or all of the problems addressed by the present invention. The applicant hereby gives notice that new claims may be formulated to such features during prosecution of this application or of any such further application derived therefrom. In particular, with reference to the appended claims, features from dependent claims may be combined with those of the independent claims and features from respective independent claims may be combined in any appropriate manner and not merely in specific combinations enumerated in the claims.

Claims

1. A device for accessing a location within a body lumen and obtaining a biopsy sample, the device comprising:

first and second elongate members;

a first cutter part connected to the first elongate member; and a second cutter part connected to the second elongate member;

wherein the first and second elongate members are moveable relative to one another and configured to move at least one of the first and second cutter parts in a longitudinal direction of at least one of the first and second elongate members between an open position and a cutter interaction position for cutting a biopsy sample.

2. A device accordingly to claim 1, wherein at least one of the first and second cutter parts has a sharp edge.

3. A device accordingly to claim 1 or 2, wherein the first and second cutter parts have opposing sharp edges.

4. A device according to any one of the preceding claims, wherein the first and second cutter parts overlap in the closed position.

5. A device according to any one of the preceding claims, wherein the cutter parts are of a circular or oval shaped cross-section.

6. A device according to claim 5, wherein the first and second cutter parts comprise cutter rings.

7. A device according to any one of the preceding claims, wherein the first elongate member comprises a dilation element at its distal end.

8. A device according to claim 7, wherein the first cutter part is located at a proximal end of the dilation element.

9. A device according to any one of the preceding claims, wherein the second cutter part is located at a distal end of the second elongate member.

10. A device according to any one of the preceding claims, wherein the cutter parts comprise a radiopaque material.

11. A device according to claim 10, wherein the cutter parts comprise stainless steel.

12. A device according to any one of the preceding claims, wherein the cutter parts are arranged at an angle to the long axis of the elongate members.

13. A device according to claim 12, wherein the cutter parts are arranged perpendicular to the long axis of the elongate members.

14. A device according to any one of the preceding claims, further comprising a chamber for holding the biopsy sample.

15. A device according to any one of the preceding claims, wherein the first elongate member comprises an inner member and the second elongate member comprises an outer sheath arranged outside the inner member.

16. A device according to claim 15, wherein at least a portion of the chamber is located within the outer sheath.

17. A device according to claim 16, wherein the chamber is defined at least in part by the inner wall of a portion of the outer sheath proximal of the second cutting part.

18. A device according to any one of claims 14 to 17, wherein the first elongate member comprises at least another portion of the chamber.

19. A device according to claim 18, wherein the at least another portion of the chamber is located between the dilation element and the first cutter part.

20. A device according to any one of the preceding claims, wherein the inner member comprises an inner sheath adapted to move over a guide-wire.

21. A device according to any one of the preceding claims, further comprising a grip located at a proximal end of the device.

22. A device according to claim 21, wherein the grip comprises first and second grip elements connected to the first and second elongate members respectively and is configured to allow a user to control relative movement of the first and second elongate members.

23. A device according to claim 22, wherein the first and second grip elements comprise finger engagement structures to permit single-handed use of the grip.

24. A device according to any one of claims 21 to 23, wherein the grip comprises a connector in fluid communication with the chamber to which a suction device can be connected to apply suction to the chamber.

25. A device according to any one of claims 21 to 24, wherein the grip comprises a plurality of graduations which provide an indication of a distance between the first and second cutter parts.

26. A device according to any one of the preceding claims, wherein at least one of the cutter parts is electrically connectable to an electric current source.

27. A device for accessing a location within a body lumen and obtaining a biopsy sample, the device comprising at least one cutter part, wherein the at least one cutter part is electrically connectable to an electric current source.

28. A device according to claim 26 or 27, wherein the electric current source comprises a high frequency alternating current source.

29. A device according to claim 28, wherein the electric current source comprises a radio frequency alternating current source.

30. A device according to any one of the preceding claims, further comprising an opening along its length through which a guide-wire can be passed, the opening providing communication between an exterior of the device and an inner guide-wire channel.

31. A device substantially as described herein with reference to the accompanying drawings.

Intellectual

Property

Office

Application No: Claims searched:

GB1616165.5 1-26, 28-30 (in part)