WO2006134483A2

WO2006134483A2 - Handpiece for an electronic scalpel for use in mni-invasive spinal surgery

Info

Publication number: WO2006134483A2
Application number: PCT/IB2006/001615
Authority: WO
Inventors: Vincenzo Cipullo; Martin Knight
Original assignee: Telea Electronic Engineering Srl; Endospine Kinetics Limited
Priority date: 2005-06-17
Filing date: 2006-06-16
Publication date: 2006-12-21
Also published as: ITVI20050175A1; WO2006134483A3

Abstract

Handpiece (1 ) for an electronic scalpel comprising: a pair of electrodes (2, 3) electrically connected to the electronic scalpel's radiofrequency generator; a pair of electric conductor wires (5, 6), each of which is connected at one extremity to one of the electrodes (2, 3) while the other extremity is electrically connected to the radiofrequency generator; a tubular shaft (4) developing mainly in the longitudinal direction and containing the pair of conductor wires (5, 6); a holder (7) connected to the tubular shaft (4). The handpiece (1 ) has actuating means (8) for sliding and extending the electrodes (2, 3) through a hole (9) in the lateral surface (10) of the front end (11 ) of the tubular shaft (4). The actuating means (8) are suitable for adjusting the position of the pair of electrodes (2, 3) with respect to the longitudinal axis (X) of the tubular shaft (4).

Description

"HANDPIECE FOR AN ELECTRONIC SCALPEL FOR USE IN MINI- INVASIVE SPINAL SURGERY".

In the name of the Companies TELEA ELECTRONIC ENGINEERING SRL - Via G. Leopardi, 23 - 36050 QUINTO VICENTINO (VI) - ITALY and ENDOSPINE KINETICS LIMITED - 123 Deans Gate - MANCHESTER 113 2 BU - UNITED KINGDOM. DESCRIPTION

This invention concerns a handpiece for an electronic scalpel particularly suitable for use in mini-invasive spinal surgery. Various methods are known for performing surgical operations, which can substantially be divided into two categories:

- the first is the so-called open surgery and consists in performing an incision of the surface tissues to create an opening that provides access to the area of the body involved in the surgical procedure; - the second is called endoscopic surgery and involves creating one or more ports on the surface of the body through which the surgical field is reached with suitable instruments.

Clearly, the first type of operation is more invasive than the second and it takes longer for the patient to recover. That is why endoscopic surgery is preferred, wherever possible, especially when the surgery affects particularly sensitive parts of the body, e.g. close to nerve endings or areas particularly critical for human health. Two examples may be the human brain, and consequently the skull, and the spinal column. To be more precise, surgery is often required on the latter of these sites to repair slipped discs, and such operations must be conducted using means and instruments capable of assuring accuracy and facility of movement during the surgical procedure, given its delicacy and potential side effects. Surgical procedures generally call for the use of scalpels that conventionally consist of a handpiece held by the surgeon, with an associated blade.

Scalpels of the type described have several acknowledged drawbacks, such as a scarce manageability and accuracy, since it is common knowledge that a blade, however sharp, produces a rough cut that cannot be limited to the required cells alone. Another drawback of these scalpels lies in that their overall dimensions make them unsuitable for use in endoscopic surgery.

To overcome the above-mentioned drawbacks and limitations, modern technology uses laser and electric scalpels, i.e. scalpels that use an electric signal, which is constant in the latter case and modulated at a frequency belonging to the laser band in the former.

This electric signal transfers an energy pulse to the tissues involved that is sufficient to dissolve the tissues and thereby achieve the required incision.

A drawback of these scalpels consists in that, although they accurately identify the area to dissect, the energy pulse that they transfer is always powerful enough to affect the surrounding tissues too.

This causes cells surrounding the tissues forming the object of the operation to dissolve or become necrotic due to the rupture of the blood vessels they contain and to thermal damage.

During surgical procedures, there is also the problem of containing bleeding, which is usually done with the aid of cotton pads.

These also have their drawbacks, such as an excessive loss of blood by the patient because the cotton acts as a sponge.

Moreover, the scarring resulting from the use of these scalpels leaves sequelae inside the human body that take a long time to reabsorb. Finally, they have the drawback of being unsuitable for minimally invasive endoscopic procedures.

The previously-mentioned electric and laser scalpels are also capable of facilitating blood clotting, however.

It is common knowledge, in fact, that blood clots because a protein substance dissolved in the plasma, called fibrinogen, becomes organized during clotting into a stable, fibrous structure called fibrin, which prevents the blood from escaping from the blood vessel through which it flows.

This conversion of fibrinogen into fibrin takes place if a kinetic energy is transferred to the molecules in the plasma so as to increase their temperature up to at least 63°, so electric and laser scalpels are used to transfer this energy and thereby facilitate blood clotting.

A drawback of these scalpels in this specific usage is that they deliver an excessive quantity of energy, sufficient to increase the temperature of the plasma molecules to more than 80-85⁰C, which is the temperature limit beyond which blood vessels collapse and the cells in the blood vessel wall die, giving rise to tissue necrosis.

To overcome all the above-mentioned drawbacks of electric and laser scalpels, which can be summarized in a poor control of the energy being delivered, there are known molecular resonance electronic scalpels, which are capable of transferring, via a handpiece, an energy suitable for achieving the ablation of the single cells involved in the surgical procedure, as well as the clotting of the blood in the vessels without making their walls collapse and thereby subsequently causing tissue necrosis. These scalpels transfer a modulated electrical energy to the tissues that is consequently easy to control.

The known electronic scalpel has the drawback, however, of being fitted with handpieces that pose problems in terms of their handling or overall dimensions, especially in the case of surgical procedures in parts of the body that are difficult to reach, such as in spinal surgery to repair slipped discs. In fact, some handpieces have the electrodes fixed in position on the outside of the body of the handpiece, making it scarcely practical, not to say hazardous, to use them for surgical operations that involve inserting the instrument in narrow spaces in the human body with a consequent risk of the electrodes becoming entangled in nerve endings or other delicate body parts. Other handpieces, on the other hand, have electrodes that extend axially from the handpiece.

Though they overcome the problem of the potential hazards of having the electrodes fixed to the outside of the body of the handpiece, these solutions carry the drawback of demanding a frontal access to the surgical field. For a start, this means that they take up space in the area to operate, interfering with the surgeon's view and, secondly, it makes then inevitably difficult to use in particularly narrow areas of the human body, where an easy frontal access to the surgical field is not always feasible. The object of the present invention is to overcome all the above-mentioned drawbacks.

To be more precise, a first object of the present intervention is to produce a handpiece for electronic scalpels that enables narrow spaces to be reached in delicate parts of the human body without the risk of the electrodes becoming entangled in nerve endings and thereby causing damage. Another object of the present invention is to produce a handpiece for electronic scalpels that enables surgical procedures to be performed without the need for frontal access to the surgical field.

Another object of the invention is to produce a handpiece for electronic scalpels that does not take up space in front of the surgical field, thus enabling the ideal positioning of the fiberoptic cameras needed to complete the procedure, for instance.

The aforesaid objects are achieved by a handpiece for an electronic scalpel that, according to the content of the main claim, comprises:

- at least one pair of electrodes electrically connected to the radiofrequency generator of said electronic scalpel;

- at least one pair of electric conductor wires, each of which is connected at one extremity to one of said electrodes and is connected electrically at the other extremity to said radiofrequency generator;

- a tubular shaft developing mainly in the longitudinal direction and containing said pair of conductor wires;

- a handpiece connected to said tubular shaft, and is characterized in that it has actuating means for sliding and projecting said electrodes through a hole in the lateral surface of the front end of said tubular shaft, said actuating means being suitable for adjusting the position of said pair of electrodes with respect to the longitudinal axis of said tubular shaft. According to the preferred embodiment, the actuating means are contained inside the holder, which is removably associated with the other end of the tubular shaft, and they comprise means for hooking up the conductor wires. In the vicinity of the above-mentioned hole, the front end of the shaft forms a seat containing a shaped striker element consisting of a solid cylindrical body with one end lying in contact with the bottom of the seat in the front end of the shaft and the opposite end presenting a shape suitable for making the electrodes slide in the direction of the hole. The fact that the electrodes extend laterally from the shaft advantageously enables them to be applied to points adjacent to the front end of the shaft, while leaving the space in front of the surgical field available for further instruments, such as the fiberoptics serving the cameras. Using the actuating means, moreover, the elongation of the electrodes can be advantageously controlled to reach the tissues that need to be resected for the purposes of the surgical procedure even a significant distance from the tip of the scalpel, without having to use a different type of tip for said purpose. Another advantage lies in the presence of the hole on the lateral surface of the front end of the shaft containing the shaped striker, which enables the electrodes of the handpiece of the invention to be extended and moved laterally with respect to the surgical field.

The aforementioned objects and advantages are better illustrated in the description of a preferred embodiment of the invention, which is provided merely as a nonrestrictive example with reference to the attached drawings, wherein: - fig. 1 shows an axonometric view of the handpiece of the invention;

- fig. 2 shows a cross-section of a detail of the handpiece of the invention;

- fig. 3 shows an axonometric view of a detail of the handpiece;

- figs. 4 to 6 show cross-sections of further details of the handpiece of the invention. The handpiece for an electronic scalpel, forming the object of the invention, is illustrated in an exploded view in fig. 1 where it is globally indicated by the numeral 1. As shown in the illustration, it comprises:

- a pair of electrodes 2, 3, electrically connected to the radiofrequency generator of the electronic scalpel;

- a pair of electric conductor wires 5, 6, each of which is connected at one extremity to one of the electrodes 2, 3, while the other extremity is electrically connected to the radiofrequency generator;

- a tubular shaft 4, developing mainly in the longitudinal direction and containing the pair of conductor wires 5, 6;

- a holder 7 connected to the tubular shaft 4.

According to the invention, the handpiece 1 has actuating means 8 for sliding and extending the electrodes 2, 3 through a hole 9 in the lateral surface 10 of the front end 11 of the tubular shaft 4. The actuating means 8 are used by the operator to manually adjust the position of the pair of electrodes 2, 3 with respect to the longitudinal axis X of the tubular shaft 4, thus enabling their adjustable extension outwards in the direction of the surgical field.

According to the preferred embodiment described herein, the actuating means 8 have means 13 for hooking up the conductor wires 5, 6 and they are contained in the holder 7, which is removably associated with the rear end 12 of the tubular shaft 4.

In the vicinity of the previously-mentioned hole 9, the front end 11 of the shaft 4, shown in fig. 2, forms a seat 14 for housing a shaped striker 15. According to the preferred embodiment described herein, this seat 14 consists of the closed tip 16 of the front end 11 of the shaft 4.

As also shown in fig. 3, the shaped striker 15 consists of a solid cylindrical body 17, a first end 18 of which lies in contact with the closed tip 16 and the other end 19 has a concave surface that forms a slide for the electrodes 2, 3 leading in the direction of the hole 9.

According to a construction variant, this other end of the shaped striker may have a flat sloping surface.

The conductor wires 5, 6 are contained, as shown in fig. 2, inside an insulating element 20 consisting preferably, but not necessarily with a double lumen, and suitable for electrically separating the wires from one another and from the tubular shaft 4.

The holder 7, as shown in fig. 4, is of the pistol type and comprises:

- a shaped tubular body 21 coaxial to the longitudinal axis X of the shaft 4 and with a first terminal part 22 associated removably with the rear end 12 of the shaft 4 by fixing means 23, and a second terminal part 24 slidingly associated with the means 13 for hooking up the conductor wires 5, 6;

- a grip 25, consisting of the previously-mentioned actuating means 8 for reciprocally moving the tubular body 21 and the hooking means 13.

Said grip 25 consists of a U-shaped body with two sides 27, 28, the first side 27 of which has its top end 29 associated with the tubular body 21 and the other side 28 has its top end 30 associated with the hooking means 13. The two sides 27, 28 are elastically joined together at the base 31. The fixing means 23 consist of a self-centering spindle comprising a tightening ring nut 32 the inside profile of which is coupled with the head 33 of the tubular body 21, which has a truncated cone shaped profile.

The head 33 consists of a plurality of concentric clamps 34 converging towards the centre, which block the tubular shaft 4 in the required position by means of the pressure exerted by the tightening of the ring nut 32, the internal profile of which forces the clamps 34 to close in on one another. As shown in figs. 5 and 6, the hooking means 13 comprise a hollow cylindrical body 36 with a first open end 39, whose cross-section is larger in diameter 37 than the diameter 38 of the tubular body 21 , and a second end 40 with a through hole 41.

The first end 39 slidingly receives the rear end 24 of the tubular body 21 , while the hole 41 in the second end 40 is for the passage of a conductor cable 42 electrically connected to the conductor wires 5, 6 by electrical contact means 43.

The hooking means 13 also comprise means 44 for anchoring the conductor wires 5, 6. Said anchoring means consist of:

- a shutter 45, inside a seat 46 provided in the hollow cylindrical body 36;

- a through hole 47 in said shutter 45, lying crosswise to the longitudinal axis T of the shutter 45 for the passage of the conductor wires 5, 6;

- elastic contrast means 48, coming between the shutter 45 and the bottom 49 of the seat 46;

- means 50 for controlling the shutter 45.

The hole 47 in the shutter 45 is in the shape of a slot with a double profile, the first profile 51 of which has a cross-section larger than that of the pair of conductor wires 5, 6, while the second profile 52 has a cross-section that is, at most, as large as that of said pair of conductor wires 5, 6.

According to the preferred embodiment of the invention described herein, the control means 50 comprise:

- a shaft 53 projecting from the shutter 45 and emerging from the hollow cylindrical body 36 through a hole 54 in the lateral surface 55 of the hollow cylindrical body 36 that coincides with the seat 46 of the shutter 45 and lies on the opposite side of the bottom 49 of said seat 46 of the shutter 45;

- a push button 56 associated with the projecting shaft 53 that is accessible to the operator.

The elastic contrast means 48 generally consist of a spring, while the electrical contact means 43, as illustrated in figures 5 and 7, comprise:

- a ring-shaped cuff 57, projecting from the inner surface of the hollow cylindrical body 36, the internal diameter 58 of which is at least as wide as the diameter 59 of the cross-section of the pair of conductor wires 5, 6, so as to achieve a sliding electrical contact with a first wire 5 of the pair of conductor wires 5, 6; - a hollow hood 60, with a cylindrical cross-section whose internal diameter

61 is at least as wide as the diameter 59 of the cross-section of the volume occupied by the pair of conductor wires 5, 6, so as to achieve a sliding electrical contact with the second wire 6 of the pair of conductor wires 5, 6. The hollow hood 60 and ring-shaped cuff 57 are electrically associated with the conductor cable 42.

In practical terms, the user takes a tubular shaft 4 complete with electrodes 2, 3 and conductor wires 5, 6, and inserts said shaft in the head 33 of the tubular body 21 on the holder 7. While inserting the shaft, the user presses and hold the push button 56 to operate the means 50 for controlling the position of the shutter 45 forming part of the means 44 for anchoring the conductor wires 5, 6, so as to enable the passage of said wires 5, 6 through the first profile 51 of the hole 47 in the shutter. After inserting the wires 5, 6 and thereby establishing the electrical contact between the wire 5 and the ring-shaped cuff 57, and between the wire 6 and the hollow hood 60, the user releases the button 56 so that the spring 48 pushes the shutter 45 back into its resting position.

In this position, the two conductor wires 5, 6 are pushed through the second profile 52 of the hole 47 in the shutter 45, thereby anchoring the wires 5, 6 due to the friction of the second profile 52 on the wires 5, 6.

Then the user axially moves the tubular shaft 4 with respect to the holder 7 to bring the pair of electrodes 2, 3 up to the hole 9 in the lateral surface 10 of the front end 11 of the shaft 4. At this point, the user attaches the shaft 4 to the holder 7 by tightening the ring nut 32 on the self-centering spindle 23.

The handpiece 1 is now ready for use and the user consequently connects the electric cable 42 to the electronic scalpel's radiofrequency generator and then takes hold of the handpiece 1 by means of the holder 7. The user brings the front end 11 of the tubular shaft 4 of the handpiece 1 into the part of the body forming the object of the surgery procedure and operates the actuating means 8 by squeezing the grip 25 in their hand.

By elastically juxtaposing the sides 27, 28 by squeezing the grip 25, the user induces the axial sliding of the shaped tubular body 21 of the holder 7 towards the hooking means 13. Since the hooking means 13 retain the conductor wires 5, 6, and consequently also the electrodes 2, 3, while the tubular shaft 4 moves together with the shaped tubular body 21, said axial sliding action makes the electrodes 2, 3 extend through the hole 9 in the front end 11 of the shaft 4. It is important to emphasize that this extension is enabled by the presence of the shaped striker 15 in the closed tip 16 of the front end 11 of the shaft 4.

Moreover, the extension of the electrodes 2, 3 is proportional to the squeezing action of the user on the grip 25, thus enabling the user to precisely control the extension of the electrodes 2, 3. In addition, the lateral extension of the electrodes 2, 3 leaves the space in front of the surgical field available, for instance, for a camera which can consequently provide the best view of the surgical field.

At this point, the user operates the power supply to the handpiece 1 to generate the energy and the consequent electrical pulses between the electrodes 2, 3 and thereby induce the ablation of the tissues with which said electrodes 2, 3 come into contact.

Said electrical pulses are modulated by the electronic scalpel's radiofrequency generator and can cause the simple ablation or dissolving of the tissues without causing any further damage to the surrounding tissues, consequently enabling the user to identify a precise area of intervention and assuring minimal invasiveness.

During the operation, a number of blood vessels are naturally ruptured and this subsequently makes it necessary to induce the clotting of the resulting bleeding. This is achieved with the same handpiece 1 by means of a different modulation of the electrical pulses so that the energy generated is sufficient only to induce the clotting of the blood in the vessels, without causing any further damage to the vessels affected or to any surrounding blood vessels.

The user then proceeds to use the two different modulation options available to dissolve the tissues or induce blood clotting until the surgical operation has been completed.

In the light of the above considerations, the handpiece of the invention achieves all the previously-stated objects.

To be precise, the handpiece for an electronic scalpel forming the object of the invention achieves the object of reaching narrow, delicate parts of the human body without the risk of the electrodes becoming entangled in nerve endings because they are contained inside the handpiece and are only extended after the area to operate has been reached.

Moreover, the handpiece of the invention achieves the object of enabling the performance of surgical operation via a lateral, not frontal access to the surgical field.

Finally, the handpiece of the invention achieves the object of not occupying the front of the surgical field, thus enabling the perfect positioning of fiberoptic cameras to guide the surgeon's maneuvers, for instance, In the executive stage, the handpiece of the invention may undergo further variants that, even if they are not illustrated in the attached drawings or described herein, should they come within the context of the following claims, will all be protected by the present patent.

Where the technical characteristics illustrated in the claims are followed by reference numbers, these are provided for the sole purpose of facilitating the reader and said reference numbers shall consequently have no restrictive effect on the coverage of each element identified as an example.

Claims

1) Handpiece (1) for electronic scalpel comprising:

- at least one pair of electrodes (2, 3) electrically connected to the radiofrequency generator of said electronic scalpel; - at least one pair of electric conductor wires (5, 6), each of which has one extremity connected to one of said electrodes (2, 3) and the other extremity electrically connected to said radiofrequency generator;

- a tubular shaft (4) developing mainly in the longitudinal direction and containing said pair of conductor wires (5, 6); - a holder (7) attached to said tubular shaft (4), characterized in that it has actuating means (8) for sliding and extending said electrodes (2, 3) through a hole (9) in the lateral surface (10) of the front end (11) of said tubular shaft (4), said actuating means (8) being suitable for adjusting the position of said pair of electrodes (2, 3) with respect to the longitudinal axis (X) of said tubular shaft (4).

2) Handpiece (1 ) according to claim 1) characterized in that said actuating means (8) consist of said holder (7), removably associated with the rear end (12) of said tubular shaft (4), with means (13) for hooking up said conductor wires (5, 6). 3) Handpiece according to claim 2) characterized in that said holder

(7) is of the pistol type and comprises:

- a shaped tubular body (21) coaxial to the longitudinal axis (X) of said shaft (4) with a first terminal part (22) removably associated with the rear end (12) of said shaft (4) by fixing means (23), and a second terminal part (24) slidingly associated with said means (13) for hooking up said conductor wires (5, 6);

- a grip (25) constituting said actuating means (8), for reciprocally moving said tubular body (21 ) and said hooking means (13).

4) Handpiece (1) according to claim 3) characterized in that said grip (25) consists of a U-shaped body with two sides (27, 28), the first of which (27) has its top end (29) associated with said tubular body (21 ) and the second (28) has its top end (30) associated with said hooking means (13), said two sides (27, 28) being joined together by a common base (31).

5) Handpiece (1) according to claim 3) characterized in that said fixing mean (23) comprise a self-centering spindle with a ring nut (32) whose internal profile contains the head (33) of said tubular body (21), which has a truncated cone shaped profile, said head (33) consisting of a plurality of concentric clamps (34) converging towards the centre.

6) Handpiece (1) according to claim 3) characterized in that said hooking means (13) comprise a hollow cylindrical body (36) with:

- a first open end (39) whose cross-section is larger in diameter (37) than the diameter (38) of said tubular body (21), said first end (39) being suitable for slidingly receiving said second end (24) of said tubular body (21);

- a second end (40) with a through hole (41 ) for the passage of a conductor cable (42) electrically connected to said conductor wires (5, 6) by electrical contact means (43);

- means (44) for anchoring said conductor wires (5, 6).

7) Handpiece (1) according to claim 6) characterized in that said anchoring means (44) comprise: - a shutter (45), inserted in a seat (46) created in the hollow cylindrical body (36), with a through hole (47) crosswise to the longitudinal axis (T) of said shutter (45), suitable for the passage of said conductor wires (5, 6);

- elastic contrast means (48) placed between said shutter (45) and the bottom (49) of said seat (46); - means (50) for operating said shutter (45).

8) Handpiece (1 ) according to claim 7) characterized in that said through hole (47) in said shutter (45) is in the shape of a slot with a double profile, a first profile (51) of which has a cross-section that is larger than the cross-section of said pair of conductor wires (5, 6), and the second profile (52) of which has a cross-section that is no larger than the cross-section of said pair of conductor wires (5, 6).

9) Handpiece (1) according to claim 7) characterized in that said control means (50) comprise:

- a shaft (53) projecting from said shutter (45) and emerging from said hollow cylindrical body (36) through a hole (54) in the lateral surface (55) of said hollow cylindrical body (36) in line with said seat (46) of said shutter (45) on the side opposite said bottom (49) of said seat (46) of said shutter (45);

- a push button (56), accessible to the operator, associated with said extending shaft (53). 10) Handpiece (1) according to claim 7) characterized in that said elastic means (48) are a spring.

11) Handpiece (1) according to claim 6) characterized in that said electrical contact means (43) comprise:

- a ring-shaped cuff (57) extending from the inner surface of said hollow cylindrical body (36) with the internal diameter (58) being at least as wide as the diameter (59) of the cross-section of said pair of conductor wires (5, 6), suitable for creating a sliding electrical contact with a first wire (5) of said pair of conductor wires (5, 6), said ring-shaped cuff (57) being electrically associated with said conductor cable (42); - a hollow hood (60) with a cylindrically shaped cross-section the internal diameter (61 ) of which is at least as wide as the diameter (59) of the cross- section of the volume occupied by said pair of conductor wires (5, 6), suitable for achieving a sliding electrical contact with the second wire (6) of said pair of conductor wires (5, 6), said hollow hood (60) being electrically associated with said conductor cable (42).

12) Handpiece (1 ) according to claim 1) characterized in that said front end (11 ) of said shaft (4) has a seat (14) for a shaped striker (15) in the vicinity of said through hole (9).

13) Handpiece (1) according to claim 12) characterized in that said seat (14) for said shaped striker (15) consists of the closed tip (16) of said front end (11 ) of said shaft (4).

14) Handpiece (1 ) according to claim 13) characterized in that said shaped striker (15) consists of a solid cylindrical body (17) with its first end (18) lying in contact with said closed tip (16) of said shaft (4) and its other end (19) presenting a concave surface suitable for enabling the sliding of said electrodes (2, 3) in the direction of said through hole (9).

15) Handpiece (1 ) according to claim 13) characterized in that said shaped striker (15) consists of a solid cylindrical body (17) with its first end (18) lying in contact with said closed tip (16) of said shaft (4) and the other end (19) presenting a flat sloping surface suitable for enabling the sliding of said electrodes (2, 3) in the direction of said through hole (9).

16) Handpiece (1) according to claim 1 ) characterized in that it has an insulating element (20) surrounding each of the wires (5, 6) in said pair of conductor wires (5, 6). 17) Handpiece (1) according to claim 16) characterized in that said insulating element (20) has a double lumen.