A METHOD AND AN APPARATUS FOR THE INSERTION OF A NEEDLE GUIDE INTO A PATIENT IN ORDER TO REMOVE TISSUE SAMPLES

Abstract: An apparatus for the insertion of a needle guide in a patient so as to remove in an ultrasound guided manner intraoperative tissue samples (biopsies) comprises a mounting member (1) for the mounting of the needle guide (2) on an ultrasonic transducer (8) at the end of a catheter. According to the invention the needle guide is predominantly flexible, but rigid at the end at the mounting member (1). As a result, a needle inserted through the needle guide (2) can be guided in the image plane of the ultrasonic transducer (8) and displayed on a display unit associated with the ultrasonic transducer (8). The needle guide (2) and the transducer (8) are operated through one and the same trocar or through their respective trocar (9, 10).

Description: Title: A method and an apparatus for the insertion of a needle guide into a patient in order to remove tissue samples. Technical Field. The invention relates to an apparatus for the insertion of a needle guide to be used by the ultrasound-guided removal of tissue samples (biopsies) and comprising a mounting member for the mounting of the needle guide on an ultrasound transducer. Background Art Needle guide systems are known in connection with ultrasonic transducers for removal of samples from internal organs. A first needle guide system is a rigid system mounted on the side of the transducer, and which ensures that the needle is inserted in the ultrasonic image plane and imaged on the display associated with the ultrasonic transducer. Such a system requires relatively much room and accordingly it can only be used in connection with open operations (laparotomy). Relatively short needles are used which may be rather thick. The same principle may apply to an ultrasonic transducer where the needle is inserted together with the transducer through a trocar tube. In this manner ultrasound guided biopsies can be performed through the trocar tube. The latter is referred to as laparoscopic ultrasound-guided biopsy. The advantage of such a procedure is that the operational wound is smaller than the wound resulting from the first system. However, like the first needle guide system, this system only allows removal of tissue samples in one direction, viz. in an outward direction from the insertion point. Such a procedure is not always sufficient, for instance in connection with removal of tissue samples from organs full of blood, such as a liver, where the shortest possible insertion of the needle into the tissue is desired. Furthermore, a flexible needle guide system is known, which is used together with an endoscope with an ultrasonic transducer built thereon, cf . PENTAX ultrasound upper G. I. fibrescope type FG-32OA. A needle placed in a spiral is inserted through the endoscope into a channel which ensures that once the needle has left the channel and been inserted into the tissue, it is moved into the image plane of the transducer and imaged on a display associated with the transducer. The endoscope is flexible and suited for insertion through the natural openings of the body, such as through the mouth and the gullet and down into the stomach. The flexibility of the endoscope renders it unsuited for removal of biopsies from internal organs in the abdominal cavity because the positioning and the retaining of the instrument in the desired position are only possible in tubular cavities, such as inside the gullet. A draw-back of the latter transducer is that the meas¬ uring system must be very flexible in order to be suited for ultrasound guided biopsies at a predetermined depth because the needle must then be able to withstand a bending of a relatively small radius. Brief Description of the Invention The object of the invention is to provide a needle guide without the above draw-backs, and which is more flexible than the previously known needle guides. An apparatus of the above type is according to the invention characterised in that the needle guide is predominantly flexible, but rigid at the end at the mounting member and can be inserted through a trocar, and that a needle inserted through the needle guide can be guided in the image plane by the ultrasonic transducer and imaged on a display associated with the ultrasonic transducer. The resulting needle guide is independent of the catheter and the movements of the operator are more free than previously allowed. Brief Description of the Drawings. The invention is explained in greater detail below with reference to the accompanying drawing, in which Fig. 1 illustrates some trocars inserted in a distended abdominal cavity of a patient, Fig. 2 illustrates how a needle guide and a surgical forceps can be inserted through their respective trocar, Fig. 3 illustrates how the forceps can grip the end of the needle guide, Fig. 4 illustrates how the needle guide can be retracted through one trocar by means of the forceps, Fig. 5 illustrates how a needle can subsequently be inserted through the needle guide, Fig. 6 illustrates how the needle is placed after the insertion, Fig. 7 is a detailed view of an embodiment of the ultrasonic transducer, Figs. 8A-8C illustrate an alternative positioning of the needle guide, Figs. 9A and 9B illustrate how the needle guide is secured to the catheter adjacent the ultrasonic transducer, Fig. 1 0 illustrates the needle guide secured to the transducer, and Fig. 1 1 illustrates how the needle guide is arranged in a groove of a cir¬ cumferential jacket surrounding the catheter. Best Mode for Carrying Out the Invention By the method according to the invention a needle guide 2 is inserted in the abdominal cavity of a patient for the purpose of removing in an ultra¬ sound-guided manner tissue samples (biopsies) from the patient through a trocar 9. The needle guide 2 comprises a mounting member for the mounting of the needle guide 2 on an ultrasonic transducer 8 at the end of a flexible catheter inserted through the same trocar 9, cf. Fig. 2. Initially, the distal end of the needle guide 2 is secured to the ultrasonic transducer 8 by means of the mounting member 1 , said ultrasonic transducer being accommodated at the end of the catheter. Subsequently, the distal end of the needle guide 2 is inserted followed by insertion of the ultrasonic trans¬ ducer 8 through the trocar 9. The distal end of the needle guide 2 is pro- vided with a small eye, which can be catched by a pair of surgical forceps 7 inserted through a second trocar 10. Accordingly, the distal end of the needle guide 2 can be pulled upwards through the second trocar 10 by means of the forceps 7 at the same time as the ultrasonic transducer 8 is inserted through the first trocar 9. Now, the transducer 8 can be placed in the desired position, and a needle with a stiletto can be inserted through the needle guide 2. The trocars are for instance of the type described in European Patent Application No. 556,056. The catheter with the ultra¬ sonic transducer can for instance be of the type B & K Medical type 8555 or of the type described in US-PS No. 4,605,009. Such a method allows the operator to place the ultrasonic plane of the transducer and the needle guide 2 very accurately relative to the internal organs and to perform ultrasound guided biopsies in arbitrary areas. The diameter of the needle is only limited by the trocar, through which the needle 3 is to be inserted. The flexibility of the needle 3 is of importance, but not as critical as previously. In addition, this method allows a separation of the ultrasonic transducer and the needle guide with the result that the cleaning of both the trans- ducer 8 and the needle guide 2 has been facilitated. The needle guide system is made of metal and can therefore be subjected to a heat steriliza¬ tion in for instance an autoclave. Commercially available transducers are cleaned in sterilizing fluids at low temperatures. The needle guide 2 is mounted on the distal end of the transducer 8, cf. Fig. 6, and comprises a holder 1 or mounting member for the securing of the needle guide 2 to the transducer 8. The needle guide may be made of plastics, such as teflon, which is not damaged by sharp needles or by a bendable spiral of stainless steel. At the end of the needle guide 2, where the holder 1 is mounted, said needle guide 2 has been made rigid either by way of securing to the holder 1 or by said needle guide 2 ending in a tube. In this manner the needle guide 2 can guide the direction of the needle 3 despite the predominantly flexible character of the needle guide 2. A relatively long needle 3 with a stiletto 4 is inserted through the needle guide 2. The needle may be relatively thick. The needle 3 can for instance be of the type "fine" where it is optionally used together with a particular handle 5. The handle 5 allows an exact positioning of the needle 3. The needle 3 can also be of the type Tru-cut, optionally used together with an automatic biopsy apparatus 5 removing a tissue sample by way of suction. The needle guide system according to the invention is relatively easy to use: The distal end of the needle guide 2 is inserted through the trocar 9, through which the transducer 8 is also to be inserted. The distal end of the needle guide 2 is catched by a pair of forceps 7 inserted through a second trocar 1 0. The distal end of the needle guide 2 is then carried upwards through the second trocar 10 at the same time as the transduce? 8 is inserted through the first trocar 9. The transducer 8 is then placed in the desired position, and the needle 3 can be inserted through the needle guide 2. The ultrasonic transducer 8 is substantially of a circular shape and com¬ prises a number of transducer elements activated in groups of for instance 5 or more juxtaposed elements, the signals to said elements being phase shifted relative to one another in such a manner that the signals emitted are focused to a predetermined degree. The ultrasonic transducer 8 and the associated electronic circuits are for instance described in US-PS No. 4,605,009. The method illustrated in Figs. 2 to 6 is, however, not applicable in case a biopsy is to be performed in the upper portion of the liver or the pan- creas. In these cases, one lung obstructs one insertion. Therefore, the apparatus of Fig. 8 has been developed, said apparatus being based on the fact that the needle guide 2 is wound around the catheter for the ultra¬ sonic transducer 8 and is inserted together with said transducer through one trocar. The mounting member 21 of the needle guide is clipped onto the catheter adjacent the transducer 8 in such a manner that said needle guide forms a permanent angle with the transducer. Figs. 9A and 9B illu¬ strate the clipping means 21 before and after the securing to the catheter. The clipping means 21 comprise the substantially circumferential members which can grip the catheter. These members are interconnected through a pivot joint, and the end of one member is shaped as a barb 22 and can be inserted in a correspondingly shaped opening 23 in the end of the other member. Fig. 1 0 is a perspective view of the clipping means 21 after the securing procedure. The permanent angle formed by the needle guide 2 and the transducer 8 can be utilized in connection with the display on a display unit associated therewith in such a manner that in advance it is possible to draw the rectilinear path of the needle on the display unit. As illustrated in Figs. 8 to 1 0, the needle guide is arranged on the outside of the catheter. In theory, nothing prevents you from drilling an opening in the catheter adjacent the transducer 8 so as to insert the needle guide 2 through said opening. The resulting needle guide is arranged at the centre of the scanning field of the transducer 8. Such an opening is, however, difficult to clean and may expose the patient to a risk of infections. It has therefore been chosen to arrange the needle guide 2 on the side of the catheter, optionally in such a manner that it is placed in a groove or notch on the side of the transducer 8. Then, the needle guide 2 need only pres¬ ent an approximate angle in the transverse direction relative to the slightly blurred radiation field of the transducer. This angle is 5 to 45 °, preferably 10 to 30°, especially 1 5 °, cf. Fig. 8B. As a result the needle is arranged inside a large portion of the scanned radiation field of the transducer 8. This field should be as narrow as possible in view of the resolution. It is, however, not possible to make this field extremely narrow, and it is thanks to the inventor that he has understood to utilize these incompletenesses. When a notch is provided adjacent the transducer, the needle guide can, of course, be further inserted towards the centre of the scanning field. The needle guide can optionally be arranged in a groove of a jacket 24 surrounding the catheter, cf. Fig. 1 1 , in such a manner that said needle guide does not cause leaks in connection with the combined insertion of said needle guide and the catheter through a trocar.

Claims: Claims 1. An apparatus for the insertion of a needle guide (2) for ultrasound guided removal of tissue samples (biopsies) and comprising a mounting member (1) for the mounting of the needle guide (2) on an ultrasonic transducer (8), c h a r a c t e r i s e d in that the needle guide (2) is predominantly flexible, but rigid at the end at the mounting member (1) and can be inserted through a trocar, and that a needle (3) inserted through the needle guide (2) can be guided in the image plane of the ultrasonic transducer (8) and imaged on a display associated with the ultrasonic transducer (8). 2. An apparatus as claimed in claim 1, c h a racter i sed in that the needle guide allows an exact ultrasound guided removal of tissue samples from the abdominal cavity of a patient at almost arbitrary angles. 3. An apparatus as claimed in claim 1 or2, ch a ra cte rise d in that the needle (3) inserted through the needle guide (2) is relatively thick, and that the ultrasonic transducer (8) and the needle guide (2) are oper¬ ated through their respective trocar (9, 10). 4. An apparatus as claimed in claim 1 to 3, c h a r a ct e r i s e d in that the needle guide is placed along the catheter with the ultrasonic transducer in such a manner that said needle guide can be inserted together with the transducer. 5. An apparatus as claimed in claim 4, c h a r a cte r i se d in that the needle guide is placed along or wound around the catheter with the ultrasonic transducer (8) in such a manner that said needle guide (2) can be inserted together with the transducer. 6. An apparatus as claimed in claim 4, c h a racte rised in that the mounting member for the mounting of the needle guide (2) on the ultrasonic transducer (8) is clipped onto said transducer in such a manner that the needle guide forms a permanent angle with the transducer. 7. An apparatus as claimed in claim 6, cha racteri sed in that the angle formed by the needle guide and the transducer is 30 to 60°, preferably 45°. 8. An apparatus as claimed in claim 6, c h a ra cte ri s ed in that in the transverse direction the needle guide forms an angle of approximate¬ ly 5 to 30°, preferably 15°, with the scanning plane of the ultrasonic transducer, said scanning plane optionally being slightly blurred. 9. An apparatus as claimed in claims 4 to 8, characterised in that the transducer comprises a groove receiving the end of the needle guide. 10. An apparatus as claimed in claim 9, c h a racte ri sed in that the groove forms an angle of 30 to 60° preferably 45°, with the ultra¬ sonic transducer. 11. A method of removing in an ultrasound guided manner intraopera- tive tissue samples (biopsies) by means of a mounting member (1) and a predominantly flexible needle guide (2) secured thereto, character- i s e d in that a guiding is performed in the image plane of the transducer (8) of a needle (3) inserted through the needle guide (2), where the guiding is displayed on a display unit associated with the ultrasonic transducer (8), said transducer (8) and said needle guide (2) being operated through their respective trocar (9, 10). 12. A method as claimed in claim 11, characterised in that the distal end of the needle guide (2) is inserted through a trocar (9), through which the ultrasonic transducer (8) is also to be inserted, whereafter the distal end of the needle guide (2) which is provided with a small eye can be catched by a surgical forceps (7) inserted through a second trocar (10), and the distal end of the needle guide (2) is pulled upwards at the same time as the ultrasonic transducer (8) is inserted through the first trocar (9), whereafter the transducer (8) is placed in the desired position and the needle (3) is inserted through the needle guide (2) prior to removal of tissue samples. AMENDED CLAIMS [received by the International Bureau on 12 September 1996 (12.09.96); original claims 1-12 replaced by amended claims 1-11 ( 4 pages )] 1. An apparatus for the insertion of a needle guide (2) for ultrasound guided removal of tissue samples (biopsies) and comprising a mounting member (1) for the mounting of the needle guide (2) on an ultrasonic transducer (8), c h a r a c t e r i s e d in that the needle guide (2) is predominantly flexible, but rigid at the end at the mounting member (1) and can be inserted through a trocar, and that a needle (3) inserted through the needle guide (2) can be guided in the image plane of the ultrasonic transducer (8) and imaged on a display associated with the ultrasonic transducer (8), and that the mounting member for the mounting of the needle guide (2) on the ultrasonic transducer (8) is secured to said transducer in such a manner that the needle guide forms a substantially permanent angle with the transducer. 2. An apparatus as claimed in claim 1, ch aracterised in that the needle guide allows an exact ultrasound guided removal of tissue samples from the abdominal cavity of a patient at almost arbitrary angles. 3. An apparatus as claimed in claim 1 or2, c h a r acter i se d in that the needle (3) inserted through the needle guide (2) is relatively thick, and that the ultrasonic transducer (8) and the needle guide (2) are oper- ated through their respective trocar (9, 10). 4. An apparatus as claimed in claim 1 to 3, c h a r a ct e r i s e d in that the needle guide is placed along the catheter with the ultrasonic transducer in such a manner that said needle guide can be inserted together with the transducer. 5. An apparatus as claimed in claim 4, ch a racte ri sed in that the needle guide is placed along or wound around the catheter with the ultrasonic transducer (8) in such a manner that said needle guide (2) can be inserted together with the transducer. 6. An apparatus as claimed in claim 1, ch aracteri sed in that the angle formed by the needle guide and the transducer is 30 to 60°, preferably 45°. 7. An apparatus as claimed in claim 1, c h ar acte r i s ed in that in the transverse direction the needle guide forms an angle of approximate- ly 5 to 30°, preferably 15°, with the scanning plane of the ultrasonic transducer, said scanning plane optionally being slightly blurred. 8. An apparatus as claimed in claims 4 to 7, characterised in that the transducer comprises a groove receiving the end of the needle guide. 9. An apparatus as claimed in claim 8, c haracterised in that the groove forms an angle of 30 to 60° preferably 45°, with the ultra¬ sonic transducer. 10. A method of removing in an ultrasound guided manner intraopera- tive tissue samples (biopsies) by means of a mounting member (1) and a predominantly flexible needle guide (2) secured thereto, character¬ i sed in that a guiding is performed in the image plane of the transducer (8) of a needle (3) inserted through the needle guide (2), where the guiding is displayed on a display unit associated with the ultrasonic transducer (8), said transducer (8) and said needle guide (2) being operated through their respective trocar (9, 10). 11. A method as claimed in claim 10, characteri sed in that the distal end of the needle guide (2) is inserted through a trocar (9), through which the ultrasonic transducer (8) is also to be inserted, whereafter the distal end of the needle guide (2) which is provided with a small eye can be catched by a surgical forceps (7) inserted through a second trocar (10), and the distal end of the needle guide (2) is pulled upwards at the same time as the ultrasonic transducer (8) is inserted through the first trocar (9), whereafter the transducer (8) is placed in the desired position and the needle (3) is inserted through the needle guide (2) prior to removal of tissue samples.

Inventors: HANSEN NIELS STENGAARD, HANSEN, NIELS, STENGAARD
Applicants: B & K ULTRASOUND SYSTEMS A S, HANSEN NIELS STENGAARD, B & K ULTRASOUND SYSTEMS A/S, HANSEN, NIELS, STENGAARD
Application year: 1996
Main classification: A61B8
IPC codes: A61B8, A61B10, A61B17