WO2007043081A2

WO2007043081A2 - Instrument for easing the anastomosis of the urethra in laparoscopic prostatectomy

Info

Publication number: WO2007043081A2
Application number: PCT/IT2006/000702
Authority: WO
Inventors: Danilo Ferrari
Original assignee: Elenor S.R.L.
Priority date: 2005-10-14
Filing date: 2006-10-03
Publication date: 2007-04-19
Also published as: ITFI20050216A1; WO2007043081A3

Abstract

A surgical instrument for easing the anastomosis of the urethra in laparoscopic prostatectomy comprising a cannula (1), suitable for being inserted into the urethra from the penis until it reaches the resection point downstream of the prostate with its distal end (1a), and equipped with radial openings (5) close to the distal end, and a plurality of needle-shaped elements (7) housed in the cannula close to the distal end and suitable for projecting for a controlled extent through the radial openings to transfix the urethra anchoring it to the cannula. Means (8, 10, 20) are foreseen for moving the needle-shaped elements (7) from a position completely retracted in said cannula to a position projecting from it so that it is substantially inclined forwards. In this way, the surgeon can actuate said means from the proximal end of the cannula to make the needle-shaped elements project from the radial openings adjusting the amount that they project up to the transfixion of the urethra, for whereby the retraction of the remaining stump of urethra can be avoided.

Description

TITLE

INSTRUMENT FOR EASING THE ANASTOMOSIS OF THE URETHRA IN LAPAROSCOPIC PROSTATECTOMY

DESCRIPTION Field of the invention

The present invention concerns in general the field of surgical instruments and more specifically refers to an instrument that can be used in prostatectomies carried out with laparoscopic surgery to ease the anastomosis of the urethra.

Background Art

As known, the prostate is an organ located between the bladder and the penis in the human male. The urethra is a duct that completely crosses the prostate placing the bladder in communication with the penis.

In a prostatectomy the entire prostate must be removed and to do this the urethra is resected immediately upstream and immediately downstream of the prostate. The surgery is completed through the anastomosis of the two remaining stumps of urethra. This last step is particularly difficult due to the restricted operating space in which the surgeon has to work and the difficulty in recovering the urethra stump from the side of the penis. Indeed, due to the elasticity of the urethra, this fragment tends to withdraw towards the pelvic floor becoming difficult to reach.

Anastomosis is normally carried out through five or six sutures stitched by the surgeon along the circumference of the two stumps of urethra and the greatest difficulty is encountered in the position of the first stitch for which the surgeon ^' cannot make use of the reference of the urethra stump that withdraws up to the pelvic floor. To apply such a stitch the surgeon uses a rigid instrument inserted in the penis that identifies the urethra canal even if it is not possible to highlight its outer wall that is embedded in the pelvic floor. This problem is currently particularly serious since the simplification of bladder-urethral anastomosis after prostatectomy is considered amqngst the "Top Unmet Needs" . Summary of the Invention The purpose of the present invention is to provide an instrument that can be used in laparoscopic prostatectomies that avoids the withdrawal of the urethra stump on the side of the penis and generates references for the cutting of the urethra itself and for its subsequent anastomosis ensuring a distribution of the sutures that is circumferentially uniform and securely attached.

This purpose is accomplished with the instrument for easing the anastomosis of the urethra according to the present invention the essential characteristics of which are set forth in claim) 1. Further important characteristics are shown in the dependent claims.

Substantially, the idea forming the basis of the present invention is to fix the urethra, before the resection of the prostate, to a rigid element inserted through the penis so as to anchor the resulting stump, downstream of the resection, in a predetermined position in this way avoiding its retraction. For this purpose a dedicated surgical instrument has been designed comprising a cannula, suitable for being inserted in the urethra from the penis until it reaches the resection point downstream of the prostate with its distal end and equipped with radial openings close to the distal end, and a plurality of needle-shaped elements housed in the cannula close to the distal end and suitable for projecting for a controlled extent the radial openings to transfix the urethra anchoring it to the cannula. Means are foreseen for displacing the needle-shaped elements from a position completely retracted in said cannula to a position projecting from it substantially tilted forwards. In this way, the surgeon can actuate said means from the proximal end of the cannula to make the needle-shaped elements project from the radial openings adjusting the extent that they project until the transfixion of the urethra.

According to a particular aspect of the invention, the needle-shaped elements have a naturally curved pointed end portion that is elastically deformable up to an v extended set up and are slidably ^' mounted on a support inside the cannula. The means for moving the needle-shaped elements control their sliding from the completely withdrawn position, in which the naturally curved pointed end portion is kept extended on the support, to the projecting position, in which the naturally curved pointed end portion is at a respective radial opening and, regaining its normal curved shape, comes out from the opening by an extent that is a function of the extent of sliding commanded. According to a further characteristic of the invention, between the cannula and the support of the needle-shaped elements a tubular screen is arranged that can slide coaxially on the support from and towards the distal end of the cannula between an advanced position, in which it closes the radial openings of the cannula from the inside and extends on the support to keep the needle- shaped elements extended along it, to a withdrawn position, in which it frees the radial openings and the end part of the support, for which reason the normally curved pointed end portions of the needle-shaped elements recover their curved shape coming out from the openings gradually as the means for moving the needle-shaped elements slide towards the distal end of the cannula.

Preferably the means for moving the needle-shaped elements comprise a tubular element arranged so that it can slide between the tubularv screen and a stem of the support of the needle-shaped elements, which are fixedly connected to the tubular element, and an actuator device of its axial sliding that can be actuated by the surgeon and connected to the proximal end of the cannula.

In a preferred embodiment of the invention the needle-shaped elements are formed from elongated steel laminar elements with high elasticity.

According to another aspect of the invention, at the distal end of the cannula longitudinal notches are formed starting from its edge for the passage of the suture needle, in particular ending with respective substantially circular widened portions.

Further characteristics and advantages of the instrument for easing the anastomosis of the urethra in laparoscopic prostatectomy according to the present invention shall become clearer from the following description of an embodiment thereof, given as a non- limiting example with reference to the attached drawings, in which: figure 1 is an overall perspective view of the instrument according to the invention; figures 2 and 3 show an enlarged perspective view of the distal end of the instrument of figure 1 in two different operating conditions; figure 4 is an enlarged longitudinal section of the front, or distal, portion of the instrument of figure 1, represented in two longitudinally separate parts for clarity of illustration; figure 5 is an enlarged longitudinal section of the rear, or proximal, part of the instrument of figure 1 represented in two longitudinally separate parts for clarity of illustration; - figure 6 is an enlarged longitudinal section of the distal portion of the instrument with an optical system inserted therein; figure 7 is an enlarged longitudinal section of the proximal portion of the instrument with the optical system inserted therein; figure 8 is a longitudinal section of the proximal part of a simplified embodiment of the instrument according to the invention.

With reference to figures 1 to 5 , the instrument for easing the anastomosis of the urethra in laparoscopic prostatectomy according to the present invention comprises a cannula 1, having a diameter compatible with the human urethra, a needle-carrier 2 arranged in the cannula 1 and a tubular screen 3 arranged so that it can slide between the cannula 1 and the needle-carrier 2. The cannula 1 has a distal end Ia at which a plurality of shaped notches 4 is formed extending from the free edge thereof and, in a position hardly more spaced -^backward, a plurality of radial openings in the form of longitudinal slots 5. The shaped notches 4 are substantially omega-shaped, with a longitudinal portion 4a that extends from the free edge of the distal end Ia and ends in a substantially circular opening 4b. The slots 5 are arranged angularly staggered with respect to the shaped notches 4. In the present embodiment of the invention six shaped notches 4 and six longitudinal slots 5 are foreseen. The needle-carrier 2 comprises a generically cylindrical end portion 2a along which equally angularly spaced throats 6 are longitudinally formed for housing needles 7. In particular, the number of needles 7 foreseen is equal to the number of longitudinal slots 5 and the needle-carrier 2 is arranged in the cannula 1 so that the throats 6 are aligned with the slots 5, the width of which is greater than that of the needles 7 to allow them to come out from slots 5. As can also be seen in figures 3 and 4, the needles 7 more exactly consist of laminar elements with an acuminated end 7a and another end 7b bent at 90° to generate an anchoring element. The needles 7 are made from high-elasticity steel and in rest conditions their ends 7a have a curved extension with respect to their longitudinal axis and inclined forwards by an angle substantially less than 90°.

When the needle-carrier 2 is completely housed in the tubular screen 3, i.e. the latter is in advanced position, the curved ends 7a of the needles 7 are forced to remain extended in the respective grooves 6, whereas when the needle-carrier 2 projects from the tubular screen 3, i.e. the latter is in withdrawn position, the ends 7a elastically return to their arched shape projecting from the slots 5 of the cannula 1, by an extent determined by the surgeon, to transfix the urethra. The needle-carrier 2 also comprises a stem 2b that extends axially from the cylindrical end 2a and on which a thrusting tube 8 is axially slidably mounted, at the distal end 8a of which an outer perimetric throat 9 is formed in which the ends 7b bent at 90° of the needles 7 engage .

The device for controlling the projection of the curved ends 7a of the needles 7 through the longitudinal slots 5 is applied to the proximal end Ib of the cannula 1. Such a device comprises a tubular support 10 to which the proximal end of the cannula 1 and the proximal end of the stem 2b of the needle-carrier 2 are fixed. In particular, the proximal end Ib of the cannula 1 engages axialIy in an end of the tubular support 10 abutting on an inner shoulder 10a thereof. The locking of the end of the support 10 to the cannula 1 is ensured by a bushing 11 screwed onto the outside of a longitudinally notched portion of said end. By continuing to tighten the bushing 11 after it has reached an abutment 12 on the end of the support 10, said end, opened by notches 13, locks radially like a pincer onto the cannula 1 contained therein. The radial component of the locking force is determined by the inclination of the thread of the threading. In order to making the locking operation easier, a holding peg 14 is placed on the bushing 11.

The needle-carrier 2 is fixed to the tubular support 10 with the end of its stem 2b by means of a pin 15 engaged in a pair of grains 16 acting in contrast with the support 10. The pin 15 extends transversally at a pair of diametrically opposite slots 17 formed on the thrusting tube 8 so as to allow the axial movement of the latter without interference. The thrusting tube 8 is anchored with its proximal end 8b to an externally threaded cap 18 through a pin 19. A sleeve 20 is cylindrically and pivotally coupled to the other end 21 of the tubular support 10 and ends with a flanged end 20a which is enclosed between a flange 22 of the tubular support 10 and a closing plate 23 fixed through screws 24 to the flange 22, whereby the sleeve 20 cannot slide on the support 10, but only rotate on it. The sleeve 20 also screws onto the cap 18 and is externally knurled to make it easier to manipulate, as shall be discussed later on.

The tubular support 10 has a further sleeve 25 axially mounted on it, to which the end of the tubular screen 3 is fixed through a transverse pin 26 locked to the sleeve 25 through a pair of grains 27. The sleeve 25 and the tubular support 10 together define a seat 28 in which a coil spring 29 is housed abutting on a collar 30 of the support 10 on which the sleeve 25 is slidably engaged. The pin 26 is arranged at a slot 31 formed longitudinally in the stem 2b of the needle-carrier 2, of a pair of diametrically opposite slots 32 formed on the thrusting tube 8 and a pair of slots 33, also diametrically opposite, formed on the proximal end Ib of the cannula 1. All of the aforementioned slots are then aligned with the longitudinal^' notches 13, also diametrically opposite, formed at the end of the tubular support 10. In this way both tlie sliding back and forth of the tubular screen 3, making the sleeve 25 slide along the tubular support 10 and overcoming the elastic reaction of the spring 29, and the sliding of the thrusting tube 8 connected with its end 8a to the needles 7 are permitted. The moving of the sleeve 25 is made easier by the presence on it of a holding flange 34.

The operation of the instrument described above is the following. The cannula 1 is inserted into the urethra through the penis with the help of an optical guidance device arranged in it, as shall be discussed later on. Once the distal end of the cannula 1 reaches the urethra resection position, the optical device is withdrawn from the cannula 1 and in it are inserted the needle-carrier 2 arranged in the tubular element) 3 and the needle actuation device, which is fixed to the cannula 1 through the bushing 11. By pulling the sleeve 25 towards the proximal end of the instrument and overcoming the elastic reaction of the spring 29, the tubular screen 3 is made to slide to move it away from the distal end Ia of the cannula 1 and uncover the free ends of the needles 7 that, due to their elasticity, return to their curved configuration and come out from the slots 5 of the cannula 1. The adjustment of the extent of projection of the tips of the needles 7 is controlled by the rotating sleeve 20 which causes the axial sliding of the thrusting tube 8 along the needle- carrier 2 and therefore causes the curved ends 7a of the v needles 7 to project out. Projecting from the slots 5 the tips of the needles 7 radially transfix the urethra firmly anchoring it to the instrument. At this point the surgeon can cut the urethra using the end part of the cannula as an abutment for the scalpel. In this way the stumps of urethra does not retract towards the penis, since it is supported by the instrument thanks to the anchoring carried out by the needles 7. The inclination forwards^' of the curved ends of the needles contributes to the good tensioning of the stump of urethra. When, having removed the prostate, the surgeon must carry out the anastomosis of ^he two stumps of urethra, the surgeon can orientate the urethra as he thinks best through the instrument and transfix' the end by passing the needle through one of the radial holes 4b of the notches 4 formed at the end of the cannula 1. Having carried out the first suture he repeats the operation through the remaining holes carrying out an anastomosis that will be, at the side of the penis, perfectly • equally spaced.

Once the anastomosis is complete, the needles 7 are withdrawn into the needle-carrier by rotating the sleeve 20 the opposite way and taking the tubular screen 3 back into the initial closing position. At this point the instrument can be removed.

The presence of the spring 29 is not essential, but it is nevertheless useful both for stabilising the position of the needles once the urethra is transfixed, since the tubular screen is pushed forwards forcing upon them, and because, when the instrument is dismounted for the insertion of the optical device, as shall be discussed later on, the tubular screen is forced to remain in its advanced position therefore completely covering the needles. In the absence of the spring in this dismounted condition the screen could indeed move back by itself or be inadvertently made to move back exposing the pins and in such a way constituting a danger to operators.

In order to make the insertion of the cannula in the urethra at the start of the intervention easier, a conventional optical device is arranged in the cannula through a suitable adapter, as shown in detail in figures 6 and 7. The optical device allows the inside of the urethra to be displayed on a monitor so as to allow the surgeon to carry out the most suitable movements for the least traumatic insertion of the cannula that is possible. With reference to such figures, a conventional optical device, for example of the "Storz" type, is indicated with 43, in the distal part 43a of which the optical-lens group is arranged, whereas a video camera (not shown) can be connected to the proximal part 43b. An adapter tube 41 allows the diameter of the tube of the standard optical system 43 to be adapted to the internal diameter of the cannula 1. AU its proximal end 41a the adapter tube 41 is welded to the proximal end of an externally threaded sleeve 40. The sleeve 40 is cylindrically connected to a support 42 at the surfaces 46 and screwed to it through the threading 40a. The support 42 has a female conical surface 42b compatible with the corresponding male conical surface of the standard optical system. A locking bushing 44 is cylindrically coupled with the support 42 and through the projections 45a of the control knobs 45, which engage in the helical grooves 42a of the support 42, it is also helically coupled with the support 42.

The standard optical system has two cylindrical i sectors diametrically in relief 43c in the proximal end of the conical attachment, whereas the locking bushing 44 has two diametrically opposite ridges 44a (broken line in figure 7) . In figure 7 the optical system has just been inserted, but not locked to the support; by rotating the locking bushing 44 in the clockwise direction, the latter advances towards the distal end of the device being coupled with the support 42 through the helical grooves 42a. The ridges 44a rest at the sectors 43a causing the axial locking of the optical system 43 to the support 42. The locking of the adapter 41 to the cannula 1 occurs in a similar way to the locking of the control device of the needles. The cannula 1 is inserted axially up to the abutment 49 of the sleeve 40 and locked to it v radially through the threaded bushing 48 that, when it is locked, causes the diametral reduction of the distal end of the sleeve 40. In this case the rotational orientation of the optical system with respect to the cannula 1 is not important .

In the case of use of optical systems with oblique lens, the direction of vision of which is not coaxial with the cannula 1, the surgeon may need to rotate the optical system with respect to the cannula. This manoeuvre can be carried out avoiding taking the sleeve 40 up to the abutment 47. The threaded coupling 40a also has the purpose of allowing the axial adjustment of the optical system with respect to the adapter tube 41. As an example a possible variation of the mechanism for controlling the advance of the needles is shown in figure 8, where the same components of the embodiment illustrated above have been given the same reference numerals. The device for the micrometric advance of the pins is replaced by a piston system 50, of the syringe type, directly fixedly connected to the thrusting tube 8 of the needles. In this case the instrument does not allow a fine adjustment of the projection of the needles, but rather is an on-off type system. The first solution described above is more suitable for making a multi-use instrument made from stainless steel, whereas the latter solution is more suitable for making a disposable instrument. In this case the system for locking the pin 15 with opposite grains 16 can also be replaced with ultrasonic welded ABS caps and the entire instrument, with the exclusion of the elastic elements, can be made from plastic materials.

Claims

1. Instrument for easing the anastomosis of the urethra in laparoscopic prostatectomies in which resection of the urethra is carried out upstream and downstream of the prostate, characterised in that it comprises a cannula (1) suitable for being inserted into the urethra from the penis until it reaches the resection point downstream of the prostate with its distal end (Ia) , said cannula having i radial openings (5) close to said distal end, a plurality of needle-shaped elements (7) being housed in said cannula close to said distal end and being suitable for projecting for a controlled extent through said radial openings (5) to transfix the urethra anchoring it to said cannula, means (8,10,20) for moving said needle-shaped elements from a position completely retracted in said cannula to a position projecting from it in substantially inclined way being also provided, said moving means being operable from the proximal end of said cannula.

2. Instrument according to claim 1, in which said needle- shaped elements (7) have a naturally curved pointed end portion (7a) that is elastic-ally deformable up to an extended set up and they are slidably mounted on a support (2) inside said cannula, said means (8,10,20) for moving said needle-shaped elements (7) being suitable for controlling the sliding of said needle-shaped elements (7) from said completely withdrawn position, in which said naturally curved pointed end portion (7a) is kept extended on said support (2), to said projecting position, in which said naturally curved pointed end portion (7a) is at a respective radial opening (5) and, returning to its normal curved shape, projects from said opening (5) by an extent that is a function of the amount of a given sliding.

3. Instrument according to claims 1 or 2 , in which between said cannula (1) and said support (2) of the needle-shaped elements (7) a tubular screen⁴ (3) is arranged that can slide coaxialIy on said support from and towards the distal end of said cannula between an advanced position, in which it closes the radial openings (5) of said cannula from the inside and extends on said support to keep said needle-shaped elements extended along it, to a withdrawn position, in which it frees the radial openings (5) and the end part of said support, whereby the normally curved pointed end portions (7a) of said needle-shaped elements recover their curved shape projecting from said openings gradually as said means (8,10,20) for moving said needle- shaped elements slide towards the distal end (Ia) of said cannula (1) . i

4. Instrument according to any one of the previous claims, in which said means for moving said needle-shaped elements comprise a tubular element (8) arranged so that it can slide between said tubular screen (3) and a stem (26) of said support (2) of the needle-shaped elements (7), said needle-shaped elements being fixedly connected to said tubular element (8) , and an actuator device (20) of its axial sliding that can be actuated by the surgeon and connected to the proximal end (Ib) of said cannula.

5. Instrument according to any one of the previous claims, in which the proximal end (Ib) of said cannula is connected to a tubular support (10) coaxial to it, which is in turn connected to the st^em (2b) of said support (2) of the needle-shaped elements (7) , said actuator device (20) of the sliding of said tubular element (8) being fixedly mounted on said tubular support (10) .

6. Instrument according to claim 5, in which said actuator device of the sliding of said tubular element (8) comprises a sleeve (20) rotatably mounted on said tubular support (10) and engaged by screw with said tubular element (8) , whereby a rotation of said sleeve (20) on said tubular support (10) corresponds to an axial sliding of said tubular element (8) .

7. Instrument according to claim 6, in which said sleeve (20) is engaged by screw on an externally threaded cap (18) and fixedly connected to said tubular element (8) .

8. Instrument according to any ^"pne of the previous claims, in which said tubular screen (3) is fixedly connected to a second sleeve (25) slidable axially on said tubular support (10) , said second sleeve being actuable by the surgeon to make said tubular screen (3) axially slide from said advanced position to said withdrawn position and vice-versa .

9. Instrument according to claim 8, in which the sliding of said second sleeve (25) is elastically counteracted to keep said tubular screen (3) in its advanced position.

10. Instrument according to any one of the previous claims, in which said radial openings (5) are in the form of longitudinal slots.

11. Instrument according to any one of the previous claims, in which said needle-shaped elements (7) are formed from elongated steel laminar elements with high elasticity.

12. Instrument according to any one of the previous claims, in which at the distal end (Ia) of said cannula (1) longitudinal notches (4) are formed starting from its edge staggered with respect to the radial openings (5) for the passage of a suture needle.

13. Instrument according to claim 12, in which said longitudinal notches (4) comprise a substantially circular widened portion (4b) .

14. Instrument according to any ^' one of the previous claims, in which said tubular"_v support (10) is removably connected to said cannula (1) .

15. Instrument according to claim 14, in which said tubular support (10) connected to said tubular screen (3), to said support (2) of the needle-shaped elements (7) and to said tubular element (8) can be replaced in said cannula (1) with an adapter device (41) for a conventional optical guidance system for the insertion of the cannula in the urethra.

16. Instrument according to claim 15, in which said adapter device comprises an adapter tube (41) engageable and reversibly lockable in said cannula (1) , at the proximal end (Ib) of which a sleeve (40) is fixed to which said optical system is connected.