Patent Publication Number: US-2009222000-A1

Title: Device and method for the treatment of tumours

Description:
The present invention relates to a device and method for the treatment of and in particular the removal of tumours, including tumours within a body of tissue such as the liver which will bleed profusely when cut. 
     When tumours occur within a body of tissue having a heavy blood supply, such as the liver, surgical removal of the tumour by resection has to be undertaken with the greatest of care if significant and potentially life threatening blood loss is to be avoided. Conventionally, liver surgery involving resection is carried out as an open procedure, with the surgeon being required to tie off or to apply localised heating to seal each of the blood vessels within the cut surface. It will be understood that this is a long and difficult procedure, and in recent years other approaches such as ablation have become more popular. In this context, ablation consists of inserting into the centre of the tumour one or more thin needles, and then heating those needles, for example using applied RF energy, to kill the tumour from the inside. Once the tumour has been entirely killed, it can simply be left in place, thereby obviating the need for resection. A typical prior art device for this purpose is disclosed in U.S. Pat. No. 6,660,002. 
     Unfortunately, there are a number of problems associated with this approach. It is difficult for a surgeon to tell whether or not all parts of the tumour have been killed. The heating effects of devices such as that disclosed in U.S. Pat. No. 6,660,002 are non-uniform, leading to concern that some cancerous cells may not be heated up sufficiently to kill them. Such areas are most likely to occur adjacent to or within larger blood vessels, since the blood itself will act as a medium for carrying heat away from those areas and thus cooling them. It will be understood that the consequence of leaving in place live cancerous cells which are adjacent to or within a major blood vessel is particularly dangerous, since it is those cells having good blood supplies that are most liable to continue growing, and indeed to continue growing rapidly. 
     The problems associated with ablation devices such as that disclosed in U.S. Pat. No. 6,660,002 are greatest for larger tumours, of diameter greater than 3 cm. With a large tumour, it may take far too long for the heat to spread from the centre to the outer periphery of the tumour. It is, of course, always open to the surgeon to use the device on individual larger sections of the tumour in turn; however this is typically quite time consuming and runs the risk that smaller areas may inadvertently be missed. 
     To overcome the risks associated with ablating a tumour and leaving it in situ, it is desirable to reliably isolate a tumour within a body of tissue and preferably remove it, without reverting to time consuming and difficult traditional resection procedures. EP-A-1100585 discloses a device for generating localised heating in a selected region of body tissue, prior to the surgical incision of that tissue. The device comprises an array of needles which are guided into the tissue or organ being treated. Microwave energy is used to raise the temperature of the selected tumour or region of tissue. Once the tumour has been isolated in this manner, if it is to be excised the ablation device must be withdrawn from the tissue and a separate manual cutting device must be inserted to remove the tumour. 
     According to a first aspect of the present invention there is provided a device for the treatment of tumours or other tissue comprising an applicator, a plurality of needles extending from the applicator, and a blade arranged for movement longitudinally along the needles. 
     The needles may be configured in a generally square or rectangular array of N×M needles, where N and M are integers. N may, for example, be 1 or 2. M may, for example, be 2 or greater, such as a number between 2 and 8, for example 2 or 3. 
     According to a second aspect of the present invention there is provided a method of treatment comprising:
         (a). Using an applicator to extend into an area of tissue a plurality of needles;   (b). Applying electromagnetic power to the needles to heat and embolise the said area of tissue; and   (c). Urging a blade longitudinally along the needles to cut into the said area of tissue.       

     A number of preferred features are set out in the dependent claims. 
     The present invention finds particular although not exclusive application in the removal of tumours within highly vascular tissues such as for example the liver, the breast, the bone, the lung, the kidney, the pancreas, the spleen or the uterus. Optionally, the device and method will be used in conjunction with a suitable imaging system such as for example ultrasound, X-Ray, MRI, or CT. 
     The needles may be diamond section in shape and, depending on the energy source being supplied, may act either as a microwave array or RF electrodes, whereby, for RF, adjacent needles may be of similar or opposing polarities. The placing of the needles may be verified by imaging and the tissue surrounding or rear the tumour then irradiated with electromagnetic radiation of RF or microwave frequency, causing the collagen surrounding the blood vessels to constrict and the blood to coagulate. 
     Having created a plane of a vascular tissue, the target tissue (such as at or near a tumour) may be safely cut by the blade. By choosing the correct size of device and number of needles used, a minimum amount of healthy tissue can be removed around the tumour. Once the device has been used to isolate and remove all of the target tissue, the remaining void may be inspected by any suitable optical means. 
     The device and method of the present invention allow surgeons to safely and efficiently isolate and remove tumours from surrounding tissue, in particular highly vascular tissue, without the need to individually seal each blood vessel surrounding the tumour or use a plurality of operating instruments. 
    
    
     
       Embodiments of the invention will now be described, by way of example, with reference to the drawings of which: 
         FIG. 1  shows a front view of the device, with the blade covered by the shell; 
         FIG. 2  shows a side view of the upper part of the device of  FIG. 1 ; 
         FIG. 3  shows a front view of the device, with the blade lowered below the shell; 
         FIG. 4  shows a front view of the device with the blade lowered for incision purposes; 
         FIG. 5A to 5D  shows several front views of the device, in which different lengths of needles are employed in conjunction with the same applicator; 
     
    
    
     Referring to  FIGS. 1 and 2 , the device  100  may be seen in more detail. The device comprises a manually-graspable applicator  102  from which a plurality of needles  103  extend. Applicator  102  thus has a preferably including recesses or concave main handle portion  105 , portion  105  contoured portions  107  which may be on opposite faces thereof enabling easy grasping of applicator  102 . The needles may optionally be divided into a first row  108  and a second row  202  in order to define an area of tissue for heating. Extending from the front face of the applicator  102 , outward of the first row  108  of needles, is a blade cover or shell  104  which is arranged to cover a blade  200  when it is not in use. Also partially covered by the shell  104  in this position is a blade holder  106  from which the blade  200  extends and which optionally acts as a connector and guide for the first  108  and second row  202  of needles. The blade  106  acts as an actuator, manual pressure on which forces the blade downwardly. 
     As can be seen from  FIG. 2 , the blade holder  106  has a shelf  206  which extends rearwardly and which connects the first  108  and second  202  rows of needles. The needles extend from the applicator  102  through the shelf  206  of the blade holder  106  which acts as a needle assisting to define the separation between the two rows of needles and hence defining the width of the tissue region which is to be heated. 
     In use, the needles are pushed into an area of tissue to be resected, for example the tissue adjacent a tumour. Typically, although not necessarily, the device will be used to cut into healthy tissue immediately adjacent a tumour or other tissue to be resected. The tumour itself is not cut into. 
     Once the needles are in place, electromagnetic energy is supplied to two adjacent needles, causing heating and embolisation of the segment of tissue between the two needles. Once that tissue has been heated to a sufficiently high temperature for a sufficient period of time to embolise any blood vessels, the power is switched off and is reapplied between the adjoining pair of adjacent needles. The process is repeated until, segment by segment, the whole of the peripheral tissue surrounding the tumour has been embolised. It will be appreciated that this process may be automated and carried out under computer control, and that the electromagnetic energy may, if desired, be applied via more than two needles at once. 
     It will be further appreciated that there are numerous ways in which the tissue S adjacent the needles may be embolised. If sufficient power is available, it may be preferable to heat up all of the individual segments between the needles at once. Any appropriate form of electromagnetic energy may be used to heat the tissue, for example RF or microwave energy. If RF is used the individual needles may be monopolar or bipolar. A control system (not shown) may be provided for operating adjacent needles with opposing polarity. If microwave energy is used, the needles may form a microwave array which would contain the microwave energy largely within the selected region of tissue. 
     Once the blood flow has been occluded within the peripheral area surrounding the tumour, for example after more than one application of the device with its needles in differing locations around at or near the tumour, any internal tumour must then die for lack of a blood supply. In many circumstances, however, it will still be desirable or necessary to remove the tumour, which can be achieved using the present invention. 
     As can be seen in  FIGS. 3 and 4 , at any point during a procedure and in particular once the tumour or other selected region has been fully or partially occluded from the surrounding tissue, the surgeon can choose to push the blade  200  downwards towards the area of tissue to be cut. The blade  200  may be controlled manually by applying pressure to the blade holder  106  or by any appropriate automated or manual actuation means (not shown). Once the blade  200  is at the appropriate level with respect to the tumour or other selected tissue, it can then cut the tissue at that point thereby at least partly excising the tumour from the surrounding healthy tissue. When it is not in use, the blade  200  may be repositioned behind the shell  104 . 
     The device may be applied multiple times, as required, to cut around the periphery of a tumour, for example with the blade  200  being operated after application of electromagnetic power before moving the needles to a new location before repeating the procedure of application of power, cutting using the blade  200 , then repositioning, and so on. 
     Generally, the needles of the device will be disposed mutually parallel, for example in first  108  and second  202  rows as described above. They may be formed of steel or any other appropriate material. As can be seen in  FIGS. 1 ,  3  and  4 , the needles may have main circular sectioned portions  109  and sharpened diamond section tips  111  to aid their passage through the tissue. In other embodiments, the needles may have a diamond shaped section along their whole length. There may be more, or fewer needles than are shown in the drawings, and the needles need not be arranged in straight parallel rows. As shown in, for example,  FIG. 1 , the needles  108  may have varying lengths, such as by having alternating lengths along each row with needles being eight short needles  113  or long needles  115 , each needle in the array of needles being either longer or shorter than all of its adjacent needles. This arrangement assists in insertion of the needles into tissue by concentrating initial insertion force over a smaller area. As shown in  FIG. 5D  the larger needles in this embodiment are 5.07 mm larger than the shorter needles. 
     The blade  200  may also be formed of steel or any other appropriate material, such as a ceramic. As can be seen best in  FIG. 2 , the blade  200  may comprise an upper portion  201  of uniform width and a lower portion  203 , the width of which decreases steadily to define a sharp point at the tip of the blade. 
     Optionally, the needles may be at least partially retractable into the applicator  102 . This enables the device  100  to use needles of a given length for insertion at a variety of depths within the tissue. Alternatively or in addition, as shown in  FIGS. 5A to 5C  in which blade  200  and shell  104  are not shown for clarity purposes, a variety of needle lengths may be used in conjunction with the applicator  102 , depending on the depth of tissue being embolised. In  FIG. 5A , four needles  103  extend 200 mm fan applicator  102  and a guide  107  may be provided for maintaining needles spaced and parallel or for providing a guide for needle insertion depth. Cutting edge  205  of blade  200  therefore extends past the below guide  107  when blade  200  is used for cutting.  FIG. 5B  shows four mid-size 110 mm needles with guide  107 .  FIG. 5C  shows for 65 mm needles  103 .  FIG. 5D  shows twelve needles, half being 110 mm and half slightly shorter. 
     The needle  103  shown in  FIGS. 5A to 5D  may be added to or removed from the applicator to provide the desired configuration. It will be understood that the present invention may be used for generating localised heating in a selected region of tissue and/or for the excision of a selected region of tissue from the surrounding tissue. The dual functionality of the device removes the need for using separate ablation and cutting instruments in surgical procedures. This provides the advantage of increased efficiency by reducing the number of instruments which a surgeon must manipulate during a surgical procedure. In addition, using a single device reduces the time taken to perform a particular procedure and minimises the number of times any region of tissue is invaded. 
     As shown in  FIG. 6A , a blister pack  300  may contain two or more applicators  102  connected to arrays of needles  103  having different configurations for ease of use. A wire  302  is fitted to each applicator  102  for the provision of electromagnetic power thereto. The blister pack  300  may also contain a tool  304  and tool  305 . Similar blister pack  308  shown in  FIG. 6B  includes applicators  102 , one of which has four needles  103  attached thereto like both of the applicators shown in  FIG. 6A , the other having 12 needles  103  in two parallel rows of six needles. Blister pack  308  includes a comb tool  306 . The blade  200  and shell  104  are not shown in  FIGS. 6A and 6B  for the purposes of clarity. Tools  304 ,  305 ,  306  may be used to clean or wipe tissue off needles  103 , and also serve as combs and ‘push off’ plates used to (a) ensure correct spacing on needle entry to reduce the chance of needle convergence during insertion, and (b) to reduce the risk of tearing tissue on removal of the device as force for withdrawal is spread across the tissues, and (c) they are also used for cleaning needles without removing the coatings. 
       FIG. 7  shows a modification to the device  100  shown in  FIGS. 1 to 4  in which the blade holder  106  is replaced with a revised blade holder  310  which may be more conveniently operated by the surgeon than the blade holder  106  of  FIGS. 1 to 4 . In particular, on one side  312  thereof, the blade holder  310  has a ramp surface  314 , and the other side  316  of the blade holder  310  as a corresponding ramp surface  318  formed as part of a manually operable blade actuation handle  320 . The ramp surfaces  314 ,  318  enable the blade  200  to be easily pushed along the needles  103  with a cutting motion into tissue  320  (shown schematically in  FIG. 7 ) after application of electromagnetic powers to the needles  103  and before removal of the needs  103  from the tissue  320 . The rearwardly extending handle  320  which extends rearwardly towards the applicator  102  and the applicators manually graspable handle  322  enable the surgeon to withdraw the blade  200  again. Although the surgeons method of operation of the device  100  may vary according to the required procedure, for example when carrying out a liver resection, the surgeon may insert the needles  103  into the tissue  320 , apply appropriate electromagnetic power, then cut using the blade  200 , then repeat the operation such as by moving to the left as shown by arrow  324  in  FIG. 7 , using the needles to ablate and coagulate the tissue and the knife  200  thereafter to cut the tissue without excessive bleeding upon each needle application and cutting cycle, and the developing procedure may therefore result in a growing cut through the tissue such as a planer or generally curved cut as may be required by the surgeon. 
       FIGS. 8 and 8B  show a further modification in which the blade holder  330  is similar to the blade holder  310  shown in  FIG. 7 . However, the blade holder  330  is provided with a rearwardly extending hook  332  which is manually operable by the surgeon for pushing the blade  200  with a cutting motion into tissue, and for pulling the blade  200  back from the extended position shown in  FIG. 8B  to the retracted position shown in  FIG. 8A . Additionally, blade holder  330  is provided with a slot  334  to which an auxiliary operating handle  336  may be optionally removably coupled for sliding the blade  200  along the needles  103 , such as when needles  103  are deeply inserted into tissue  320 . 
     As shown in  FIGS. 8A and 8B , the tip portions B 38  of needles  103  may conduct into tissue and upper portions  340  needles may be insulated. 
       FIGS. 9A ,  9 B and  10 A show a further modification in which blade holder  400  has bores  402  (8 bores) enabling sliding of the blade  200  along the needles  103 . Blade holder  400  has a rearwardly extending rod  404  which extends through a bore  406  in applicator  102  and is operable by a manually operable knob  408  on the end thereof  410  opposite the blade holder  400 . This configuration allows the blade to be conveniently slid along the needles  103  without the surgeon having to perform manual operation of the blade  200  with a hand forward of the applicator  102  towards the tissue into which the needs are inserted, thereby providing good visibility from the surgeon. Also rod  404  is centrally located on rear surface  414  of blade holder  400  thereby avoiding unnecessary application of bending moments to needles  103  and minimum friction during the sliding movement of the blade holder  400  along the needles  103 . As shown in  FIG. 10A , the twelve needles  103  are in two parallel rows  420 ,  422  and knife  200  is parallel with and longitudinally slidable along the rows  420 ,  422 , but if located between the rows  420 ,  422 .  FIG. 11   a  which is a section on plane XIA in  FIG. 10A , shows how needles  103  may be inserted into healthy tissue  430  and the knife  200  used to cut tumour  432  off tissue  430 , such as during a liver resection operation, such as by repeatedly inserting needs  103  into tissue  430  to resect along a plane or curve as described above. In a modification of the embodiment of  FIGS. 9A ,  9 B and  10 A which is shown in  FIGS. 10B and 11B , blade  200  may be located using blade holder  401  parallel to an outside needle rows  420 ,  422 , with one needle row  420  between blade  200  and other needle row  422 . 
     Various modifications may be made to the embodiments described herein without departing from the scope of the invention as defined by the claims hereto as interpreted under Patent Law.