GB2403419A

GB2403419A - Tissue extraction tool

Info

Publication number: GB2403419A
Application number: GB0315729A
Authority: GB
Inventors: Richard Owen; Charlie Dean; David Drake; Mark Dennehey
Original assignee: PA Holdings Ltd
Current assignee: PA Holdings Ltd
Priority date: 2003-07-04
Filing date: 2003-07-04
Publication date: 2005-01-05
Also published as: GB0315729D0

Abstract

A tissue extraction tool that includes a curved, stiff but flexible tube (15 on FIG 7) that emerges from the tip of a shaft that penetrates through the body to reach the target tissue. The curved, stiff but flexible tube is retractable and rotatable such that a cylindrical area of tissue (15 on FIG 9) around the site of penetration can be harvested. Penetration is rendered easier for the user and more comfortable for the patient by a power unit (1 on FIG 1) providing penetration assistance. The power unit also powers the movement of the curved, stiff but flexible tube. Harvesting is further assisted by connection of a collecting tube (14 on FIG 6) to a peristaltic pump. A shoulder (5 on FIG 2) on the outer metal shaft ensures that the penetrations are made to a known, safe, depth. Extraction tools comprising drilling elements disposed in the shaft are also claimed.

Description

1 2403419

TISSUE EXTRACTION TOOL

Tissue extraction relates to the extraction of living tissue from within living animals. There are many examples of biological tissue extraction, e.g. biopsy of tissue for analysis, removal of tumours for cancer therapy and the removal of bone marrow for subsequent analysis or cell-based therapy. The invention described below is appropriate for many types of tissue extraction. For clarity, bone marrow extraction will be used as an example.

Bone marrow is extracted from within bones. The bone marrow can then be used for analysis, for example in the diagnosis of many haematologica] conditions. Also, severa] haematologica] malignancies are treatable by bone marrow transplantation. Bone marrow can be extracted, for example from the pelvic bone, and transplanted into a recipient. The biopsy process, where marrow is typically extracted for analysis, typically takes around 15 minutes for a skilled operator. The harvesting process where bone marrow is typically extracted for transplantation from a healthy donor, typically takes several hours and two highly trained professionals. An estimated 500,000 biopsies and 5,000 harvests are performed worldwide per year.

The current procedures for biopsy and harvesting suffer several drawbacks, namely: À During harvesting as currently practiced, up to 40 holes may be drilled into each side of the donor's pelvis. This causes significant local trauma and discomfort and is also time-inefficient, À Neither biopsy nor sampling is currently powered, and both require physical effort; this leads to operator discomfort after one harvesting procedure, or 5 or more sampling procedures, À If inexperienced, operators are likely to take more time to carry out the procedure and cause avoidable pain to the patient, À Both the skil] level required and the pain caused to the patient may decrease the number of procedures that haematology units are currently prepared to carry out.

In one aspect, the present invention provides a device for extracting biological material from a human or animal body, the device comprising an elongate hollow shaft having a distal end for insertion into the human or animal body and a proximal end, and an elongate flexible collecting tube disposed in the shaft, the collecting tube being rotatable within the shaft and longitudinally displaceable in a longitudinal direction along the length of the shaft, the collecting tube having a distal end portion which is bendable relative to the shaft so that when the end portion is selectively disposed in an external position distally remote from the distal end of the shaft, a free end of the end portion is laterally spaced from the dista] end of the shaft, and the end portion being deformable so that the end portion is selectively retractable into the shaft so as to be disposed in an internal position within the shaft.

In one embodiment, the collecting tube is preformed with a bend at the distal end portion.

In another embodiment, the device further comprises an outer core surrounding at least a part of the dista] end portion of the collecting tube, the outer core being preformed with a bend thereby to impart a bend to the dista] end portion when in the external position.

Preferably, the distal end portion is curved. The device may further comprise a drive for rotating and/or translating the collecting tube. The device may also further comprise a pump for applying suction to a proximal end of the collecting tube. Preferably, the elongate hollow shaft has an outer surface forming a distal end part terminating, at a proximal end of the distal end part, in a shoulder of larger cross- section than the distal end part.

In a second aspect, the present invention provides a device for extracting bio]ogica] material i from a human or animal body, the device comprising an elongate hollow shaft having a distal end for insertion into the human or animal body and a proximal end, an elongate drilling element rotatably disposed in the shaft, the drilling element having a sharp dista] end adapted to drill through bone, and a drive for rotating the drilling element.

Preferably, the elongate hollow shaft has an outer surface forming a dista] end part terminating, at a proximal end of the distal end part, in a shoulder of larger cross-section than the distal end part.

In a third aspect, the present invention provides a device for extracting biological material from a human or animal body, the device comprising an elongate hollow outer shaft having a distal end for insertion into the human or animal body and a proximal end, an elongate hollow inner shaft disposed within the outer shaft and rotatable and longitudinally movable relative thereto, the inner shaft having a distal end portion having a cutting edge for cutting into biological material, and an elongate drilling element rotatably disposed in the inner shaft, the drilling element having a sharp distal end adapted to drill through bone Preferably, the device further comprises a drive for rotating the drilling element.

Preferably, the elongate hollow outer shaft has an outer surface forming a distal end part terminating, at a proximal end of the distal end part, in a shoulder of larger cross-section than the distal end part. Preferably, the device further comprises a pump for applying suction to a proximal end of the inner shaft.

In a fourth aspect, the present invention provides a device for extracting biological material from a human or animal body, the device comprising an elongate hollow outer shaft having a distal end for insertion into the human or animal body and a proximal end, an elongate hollow inner tube disposed within the outer shaft and rotatable and longitudinally movable relative thereto, the inner tube having a distal end portion having a cutting edge for cutting into biological material, and a pump for applying suction to a proximal end of the inner tube.

Preferably, the elongate hollow outer shaft has an outer surface forming a distal end part terminating, at a proximal end of the distal end part, in a shoulder of larger cross-section than the distal end part. Preferably, the inner tube comprises a flexible collecting tube having a distal end portion which is bendable relative to the outer shaft so that when the end portion is selectively disposed in an external position distally remote from the distal end of the outer shaft, a free end of the end portion is laterally spaced from the distal end of the shaft, and the end portion being deformable so that the end portion is selectively retractable into the shaft so as to be disposed in an internal position within the shaft. In one embodiment, the collecting tube is preformed with a bend at the dista] end portion. In another embodiment, the device further comprises an outer core surrounding at least a part of the distal end portion of the collecting tube, the outer core being preformed with a bend thereby to impart a bend to the distal end portion when in the external position.

In a fifth aspect, the present invention provides a kit of parts for a device for extracting biological material from a human or animal body, the kit comprising an elongate hollow outer shaft having a distal end for insertion into the human or animal body and a proximal end, a handle attached to the outer shaft for gripping by a user, and a drive in the handle for selectively rotating and/or longitudinally displacing along the outer shaft an elongate member located within the outer shaft, and at least one of: an elongate hollow inner shaft to be disposed within the outer shaft and rotatable and longitudinally movable relative thereto, the inner shaft having a dista] end portion having a cutting edge for cutting into biological material; an elongate drilling element to be rotatably disposed in the shaft, the drilling element having a sharp distal end adapted to drill through bone; and an elongate flexible collecting tube to be disposed in the shaft, the collecting tube being rotatable within the shaft and longitudinally displaceable in a longitudinal direction along the length of the shaft, the collecting tube having a distal end portion which is bendable relative to an adjacent portion of the collecting tube so that, in use, when the end portion is selectively disposed in an external position distally remote from the dista] end of the shaft, a free end of the end portion is laterally spaced from the distal end of the shaft, and the end portion being deformable so that the end portion is selectively retractable into the shaft so as to be disposed in an internal position within the shaft.

In a sixth aspect, the present invention provides a method of extracting biological material from a human or animal body, the method comprising the steps of: (a) inserting into the human or animal body a distal end of an elongate hollow shaft; (b) disposing a flexible collecting tube in the shaft; (c) displacing the collecting tube in a longitudinal direction along the length of the shaft so that a distal end portion of the collecting tube is disposed in an external position distally remote from the distal end of the shaft, the distal end portion thereby being bent relative to the shaft so that a free end of the distal end portion is laterally spaced from the distal end of the shaft, the displacement causing biological material to enter the free end; and (d) applying suction to a proximal end of the collecting tube to suck biological material in the collecting tube to a collection device.

Preferably, the method further comprises the steps of: s (e) retracting the end portion into the shaft so as to be disposed in an internal position within the shaft; (f) rotating the connecting tube; and repeating steps (c) and (d).

Preferably, the method is for collecting bone marrow, and before step (b) an elongate drilling element is disposed in the shaft, the drilling element having a sharp distal end adapted to drill through bone, and the drilling element is rotated to drill a hole in the bone of the patient.

Preferably, before step (b) an elongate hollow inner shaft is disposed within the outer shaft, the inner shaft having a dista] end portion having a cutting edge for cutting into biological material, the inner shaft is rotated and/or longitudinally moved to collect biological material therein, and the biological material is removed by suction applied to a proximal end of the inner shaft.

The suction may be applied continuously by a pump. Preferably, in step (a) the dista] end of the elongate hollow shaft is inserted to a preselected depth defined by a shoulder provided at the outer surface of the elongate ho]]ow shaft.

The preferred embodiments of this invention is a new too] used both for biopsy and harvest, and it renders both procedures significanl]y less traumatic and time consuming. Its key advantages over existing systems are: À A curved flexible sampling tube enables more marrow to be extracted from each hole drilled into the pelvis, thus minimising both the number of traumatic bony penetrations per donation and the amount of tissue and bony trauma caused per penetration, À It is powered, so obviating the need for the heavy pushing which is responsible for most patient and operator discomfort, À A peristaltic pump connected to a marrow collection bag further speed up the harvesting process.

Its benefits are extracting large amounts of tissue from inside the body without having to make numerous holes in skin, bone or surrounding tissue. This decreases time, trauma and the chance of subsequent infection. It is obvious that these features make the concept also suitable for tissue extraction other than bone marrow, for example tissue biopsy, tumour I extraction or other extraction processes involving biological tissue.

Accordingly, the process of operation for bone marrow extraction, and essential technical features of this new invention are as follows: À A small slit will be made in the patient's skin around the pelvis.

À The device will be introduced into the skin and pushed through the subcutaneous tissue under the skin until it contacts the pelvic bone. The sharp inner core (7) will aid its passage through the tissue.

À Once the inner core touches the pelvic bone, the motor will be started by pressing the button (2). The inner core (7) will rotate and drill through the bone. Once a hole is made in me bone, the shoulder on the outer shaft (5) will prevent the device; entering too far into the pelvis. It will also stop the operator having to guess the depth of penetration. If required, the length of projection of the metal shafts from the handheld power unit can be extended to suit different patient sizes (shown in Figure 3) À If required, a marrow sample core can be taken and fluid from around the marrow can be sampled for later diagnostic tests (as shown in Figure 4). This is accomplished by removing the inner sharp core and applying a suction to the back end of the inner hollow shaft (10). The suction can be provided by attaching a syringe to the Luer lock fitting on the back of the inner hollow shaft. Once the fluid sample is collected, the inner hollow shaft is pushed forwards into the bone marrow.

It cores some of the marrow which is shown inside the tube (] l). The inner hollow shaft is then removed out of the back of the outer hollow shaft and the marrow core extracted from it.

À The device will then be switched to harvesting mode. A tube that is stiff but flexible will be introduced through the back end of the outer hollow meta] tube with the shouldered notch (Figure 5). The tube has a curve in it so that when it comes out of the end of the outer metal tube, it will project out at an angle to the main axis of the device (Figure 7, 15). The tube has a sharp edge so that when it comes out of the metal tube and into the marrow it will cut and core a section of the marrow. The marrow that is inside the flexible tube will be exkacted out of the marrow and; sucked along the tube by a suction pressure applied by a peristaltic pump which is attached to the far end of the flexible tube shown extending away from the handheld I power unit in Fig 6 (14). The pump will extract the cored sample and deposit it into a bag which is connected to the far end of the flexible tubing. The stiff but flexible tube is then withdrawn from the marrow, back into the metal outer tubing. It is then rotated a small fraction of a revolution about its short axis (for example 40 ) as shown in Fig 8. However, other angles of rotation would be equally appropriate. I À The motions described above are now repeated. Therefore, the stiff but flexible tube is pushed into the marrow, retracted, rotated and re- inserted into the marrow many times all while a constant suction is applied to the tube by the peristaltic pump on its I far end. The process ensures the extraction of marrow from a large cylindrical space within the bone (fig 9, 16). This area is much larger than could be accessed by a simple conventional rigid needle. At the end of the process, all the marrow from within the cylinder shown in Fig 9 is extracted and transferred to a plastic collection bag for subsequent therapy.

À The motion of the stiff but flexible tubing is powered by a rechargeable clip-on/off power unit that can also give a low speed power assist to the operator if required during drilling; À The needle and tubing are sterile and disposable, whereas the power unit is reusable, À Appropriate coatings throughout wild control clotting in the system. ; The harvesting tube (when out of the outer hollow tube) will have a bend in it. This bend could be of any angle. The harvesting tube must be flexible enough, so that when it is I introduced into the end of the outer hollow tube, it can straighten suffcient]y to pass through its centre. When in the outer hollow tube, it will be essentially straight and have no bend. Once it comes out of the hollow outer tube, its curved nature will cause it to deviate from the straight-ahead position thus allowing it to access more tissue. The precise nature of the curve that it takes as it exits the tube is not critical. However, the greater the angle from the straight ahead position, up to a maximum of 90 degrees, the more tissue it can harvest. It is possible (though not advantageous) that the tube could bend by as much as 180 degrees once inside the body.

The tube material must be both stiff enough and its end sharp enough to penetrate the tissue being sampled. The opening of the tube must be very sharp (i.e. have a very smal] surface area). It is possible that the very edge of the tube will be made of a different material to the I rest of the tube. If the harvesting tube is too flexible and not stiff enough, it will not be able to penetrate the tissue and so will distort, producing very tight bends and kinks in it. This will prevent the sharp edge of the tube being pushed through the tissue and so will prevent any coring and harvesting action. If it is not flexible enough and too stiff, it will not be able to distort sufficiently to enter the outer hollow tube. I The harvesting tube will probably be made of several different materials as it needs several different properties: Its open edge must be sharp enough to penetrate tissue Its front end that is introduced into the body must have the balance between stiffness and flexibility as described above.

Its tail end that is connected to the harvesting bag must be suitable to pass through a peristaltic pump and have peristalsis performed on it It may be advantageous for the harvesting tube to have a serrated edge and to be rotated (either in complete circles or backwards and forwards through a few degrees) to help it penetrate the tissue Some options for harvesting tube materials: À Thin surgical steel connected to latex tubing À Plastic tubing with wire support at its front end and a sharp metal edge À Shape memory alloys (such as nitinol) connected to latex tubing. These have the advantage of"shape memory effect" which would allow the required curve to be produced only when the metal is exposed to body temperature À Metal in the form of springs with closely bound coils It is also possible to use a stiff and flexible but not permanently curved or bent harvesting tube and using a curved outer hollow core. This would require the user to manually rotate the device, but when used with the same in and out coring action of the inner harvesting tube, would still allow more tissue to be accessed than a simple trephine. ; A preferred embodiment of the invention will now be described with reference to the accompanying drawing in which: FIG 1 Shows the battery powered motor that assists in initial drilling and powers the movement of t the flexible tube (I) Shows the power button (2) FIG2 Shows the shoulder on the needle (3) À Shows how the inner needle (4) removes approximately 1 5mm sample of marrow À Shows how the shoulder (5) on the needle locates against bone ensuring correct depth of penetration FIG 3 Shows how the needle length (6) can be adjusted to suit different patient sizes FIG4 Shows a cross section of the needle portion of the device, demonstrating: The sharp inner core (7) The pelvic bone in cross section (8) How the correct depth of insertion is maintained by the shoulder on the outer needle (9) The inner needle without the sharp inner core (10) Bone marrow cored out by insertion of the inner hollow needle (11)

FIG

Shows the additional section (12) that adds bone marrow harvesting capability- the flexible tube slides within the sampling mechanism Shows how the drive mechanism connects into power unit on sampler (13) FIG6 Shows the collection tube (14) which is connected to a peristaltic pump and bone marrow collection bag FIG 7 Shows how the sampling tube is curved at an angle (15) for accessing a greater area of I marrow FIG 8 Demonstrates automatic retraction and rotation of the flexible sampling tube FIG9 Shows the cylindrical volume of potential marrow removal (] 6) by the flexible sampling tube FIG l O Shows cross section of possible flexible sampling tube movement FIG 1 1 Shows the alternative option of using a curved outer hollow tube (17) and a stiff but flexible (but not permanently deformed) inner harvesting tube (18).

Claims

CLAIMS: 1. A device for extracting biological material from a human or

animal body, the device comprising an elongate hollow shaft having a distal end for insertion into the human or animal body and a proximal end, and an elongate flexible collecting tube disposed in the shaft, the collecting tube being rotatable within the shaft and longitudinally displaceable in a longitudinal direction along the length of the shaft, the collecting tube having a distal end portion which is bendable relative to the shaft so that when the end portion is selectively disposed in an external position distally remote from the distal end of the shaft, a free end of the end portion is laterally spaced from the distal end of the shaft, and the end portion being deformable so that the end portion is selectively retractable into the shaft so as to be disposed in an internal position within the shaft.
2. A device according to claim 1 wherein the collecting tube is preformed with a bend at the distal end portion.
3. A device according to claim 1 further comprising an outer core surrounding at least a part of the distal end portion of the collecting tube, the outer core being preformed with a bend thereby to impart a bend to the distal end portion when in the external position.
4. A device according to any one of claims 1 to 3 wherein the distal end portion is curved.
5. A device according to any foregoing claim further comprising a drive for rotating and/or translating the collecting tube.
6. A device according to any foregoing claim further comprising a pump for applying suction to a proximal end of the collecting tube.
7. A device according to any foregoing claim wherein the elongate hollow shaft has an outer surface forming a distal end part terminating, at a proximal end of the distal end part, in a shoulder of larger crosssection than the distal end part. v
8. A device for extracting biological material from a human or animal body, the device comprising an elongate hollow shaft having a distal end for insertion into the human or animal body and a proximal end, an elongate drilling element rotatably disposed in the shaft, the drilling element having a sharp distal end adapted to drill through bone, and a drive for rotating the drilling element.
9. A device according to claim 8 wherein the elongate hollow shaft has an outer surface forming a distal end part terminating, at a proximal end of the distal end part, in a shoulder of larger cross-section than the distal end part.
10. A device for extracting biological material from a human or animal body, the device comprising an elongate hollow outer shaft having a distal end for insertion into the human or animal body and a proximal end, an elongate hollow inner shaft disposed within the outer shaft and rotatable and longitudinally movable relative thereto, the inner shaft having a distal end portion having a cutting edge for cutting into biological material, and an elongate drilling element rotatably disposed in the inner shaft, the drilling element having a sharp distal end adapted to drill through bone
11. A device according to claim 10 further comprising a drive for rotating the drilling element.
12. A device according to claim 10 or claim 11 wherein the elongate hollow outer shaft has an outer surface forming a distal end part terminating, at a proximal end of the distal end part, in a shoulder of larger cross-section than the distal end part.
13. A device according to any one of claims 10 to 12 further comprising a pump for applying suction to a proximal end of the inner shaft.
14. A device for extracting biological material from a human or animal body, the device comprising an elongate hollow outer shaft having a distal end for insertion into the human or animal body and a proximal end, an elongate hollow inner tube disposed within the outer shaft and rotatable and longitudinally movable relative thereto, the inner tube having a distal end portion having a cutting edge for cutting into biological material, and a pump for applying suction to a proximal end of the inner tube.
15. A device according to claim 14 wherein the elongate hollow outer shaft has an outer surface forming a distal end part terminating, at a proximal end of the distal end part, in a shoulder of larger cross- section than the distal end part.
16. A device according to claim 14 or claim 15 wherein the inner tube comprises a flexible collecting tube having a distal end portion which is bendable relative to the outer shaft so that when the end portion is selectively disposed in an external position distally remote from the distal end of the outer shaft, a free end of the end portion is laterally spaced from the dista] end of the shaft, and the end portion being deformable so that the end portion is selectively retractable into the shaft so as to be disposed in an internal position within the shaft.
17. A device according to claim 16 wherein the collecting tube is preformed with a bend at the distal end portion.
18. A device according to claim 16 further comprising an outer core surrounding at least a part of the distal end portion of the collecting tube, the outer core being preformed with a bend thereby to impart a bend to the distal end portion when in the external position.
19. A kit of parts for a device for extracting biological material from a human or animal body, the kit comprising an elongate hollow outer shaft having a distal end for insertion into the human or animal body and a proximal end, a handle attached to the outer shaft for gripping by a user, and a drive in the handle for selectively rotating and/or longitudinally displacing along the outer shaft an elongate member located within the outer shaft, and at least one of: an elongate hollow inner shaft to be disposed within the outer shaft and rotatable and longitudinally movable relative thereto, the inner shaft having a distal end portion having a cutting edge for cutting into biological material; an elongate drilling element to be rotatably disposed in the shaft, the drilling element having a sharp distal end adapted to drill through bone; and an elongate flexible collecting tube to be disposed in the shaft, the collecting tube being rotatable within the shaft and longitudinally displaceable in a longitudinal direction along the length of the shaft, the collecting tube having a distal end portion which is bendable relative to an adjacent portion of the collecting tube so that, in use, when the end portion is selectively disposed in an external position distally remote from the distal end of the shaft, a free end of the end portion is laterally spaced from the distal end of the shaft, and the end portion being deformable so that the end portion is selectively retractable into the shaft so as to be disposed in an internal position within the shaft.
20. A method of extracting biological material from a human or animal body, the method comprising the steps of: (a) inserting into the human or animal body a distal end of an elongate hollow shaft; (b) disposing a flexible collecting tube in the shaft; (c) displacing the collecting tube in a longitudinal direction along the length of the shaft so that a distal end portion of the collecting tube is disposed in an external position distally remote from the distal end of the shaft, the distal end portion thereby being bent relative to the shaft so that a free end of the distal end portion is laterally spaced from the distal end of the shaft, the displacement causing biological material to enter the free end; and (d) applying suction to a proximal end of the collecting tube to suck biological material in the collecting tube to a collection device.
21. A method according to claim 20 further comprising the steps of: (e) retracting the end portion into the shaft so as to be disposed in an internal position within the shaft; (f) rotating the connecting tube; and repeating steps (c) and (d).
22. A method according to claim 20 or claim 21 which is for collecting bone marrow, and wherein before step (b) an elongate drilling element is disposed in the shaft, the drilling element having a sharp distal end adapted to drill through bone, and the drilling element is rotated to drill a hole in the bone of the patient.
23. A method according to any one of claims 20 to 22 wherein before step (b) an elongate hollow inner shaft is disposed within the outer shaft, the inner shaft having a distal end portion having a cutting edge for cutting into biological material, the inner shaft is rotated and/or longitudinally moved to collect biological material therein, and the biological material is removed by suction applied to a proximal end of the inner shaft.
24. A method according to any one of claims 20 to 23 wherein the suction is applied continuously by a pump.
25. A method according to any one of claims 20 to 24 wherein in step (a) the distal end of the elongate hollow shaft is inserted to a preselected depth defined by a shoulder provided at the outer surface of the elongate hollow shaft.
26. A device for extracting biological material from a human or animal body substantially as hereinbefore described with reference to the accompanying drawings.
27. A kit of parts for a device for exkacting biological material from a human or animal body substantially as hereinbefore described with reference to the accompanying drawings.
28. A method of extracting biological material from a human or animal body substantially as hereinbefore described with reference to the accompanying drawings.