DE29912897U1 - Surgical clip applier - Google Patents

Description

Surgical clip applicator

The invention relates to an application instrument for U-shaped surgical clips with a magazine having a distal and a proximal end, in which several clips are mounted one behind the other in a guide so as to be longitudinally displaceable, with a feed plate on the underside of the magazine, which rests on the back of the clips by means of spring-loaded tabs and which can be pushed back and forth by means of a feed device over at least one clip distance parallel to the guide of the magazine and thereby pushes the clips together in the direction of the distal end of the magazine during the feed movement.

Such an application instrument is known, for example, from DE 196 03 889 A1. In this known application instrument, a rod-shaped feed device at the proximal end of the feed plate engages the latter and pushes it forwards during the feed movement and then pulls it back again. During the feed movement, the feed plate must transfer thrust forces to all clips arranged in the magazine, which are each moved forwards by one position during this feed movement.

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This is easily possible with conventional application instruments, but considerable difficulties arise when the application instrument is to be made smaller, in particular when the external diameter of the instrument is to be reduced. If this diameter is reduced, the components arranged in the shaft must also be reduced in size, and this can lead to strength problems with the individual parts.

It is an object of the invention to design an application instrument of the generic type in such a way that even when the dimensions are reduced, the high forces required to advance the clips can be easily provided.

This object is achieved according to the invention in an application instrument of the type described at the outset in that the feed device acts on the feed plate when it is advanced at a point which is at least half the length of the feed plate away from the proximal end of the feed plate.

This design prevents the feed plate from being pushed forward from the proximal end during advancement. With the new design, in which the feed device engages the feed plate at a point offset in the distal direction by at least half the length of the feed plate, a maximum of half of the feed plate is pushed during the advance movement, the other half is pulled. If

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If the point of attack is shifted further in the distal direction, this ratio changes even further, and the pulled area of the feed plate becomes even larger. The tensile stress during the feed movement is more favorable for the feed plate, as buckling of the feed plate under the force of thrust forces is avoided. The forces are significantly greater during the feed movement than during the retraction movement of the feed plate, as the clips in the magazine also have to be pushed forward during the feed movement, while during the retraction movement the feed plate is simply pulled empty past the pushed clips.

This design makes it possible to use feed plates that are made of very thin materials and therefore do not have a great deal of resistance to buckling, even when beads are embossed.

The strength of this feed plate can be further increased by the feed plate having a downwardly projecting central region in its region distal to the point of application of the feed device, which extends at a distance from the clips guided in the magazine. This downwardly projecting central region forms a stiffening bead which strengthens this region of the feed plate against undesirable buckling, so that relatively high thrust forces can be transmitted in this region, which takes up a maximum of half the length of the feed plate.

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It can also be provided that the feed plate has an upwardly projecting central region in its region proximal to the point of application of the feed device, which runs close to the clips guided in the magazine. This upwardly projecting central region can also be designed in the form of a bead and serves to stiffen it. In addition, a space is created in the proximal region of the feed plate below it to accommodate the feed device, so that the overall height of the application instrument can be reduced. It is also advantageous that additional stiffening can be achieved by the different direction of the beads in the distal region and in the proximal region of the feed plate.

According to a particularly preferred embodiment, the feed device is a rod which is arranged under the feed plate and can be pushed back and forth and which, when pushed forward, comes to rest with a lateral projection on an edge of the feed plate which projects downwards from the plane of the feed plate.

Preferably, this edge is formed by the downwardly projecting central area of the feed plate. In contrast to known application instruments, it is no longer necessary to have the feed device rest against a downwardly directed, elastic tongue of the feed plate, which could be undesirably deformed under higher stress, but

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The force is introduced through the downwardly projecting central region of the feed plate, so that the feed device does not exert a torque on a part connected to the feed plate, but can introduce the feed forces into the feed plate directly in the feed direction.

In a further preferred embodiment, it is provided that the rod is arranged proximal to the lateral projection close to the central region of the feed plate and has recesses which form receiving spaces for the resilient tabs of the feed plate when the rod is pushed back.

Such a design makes it possible to arrange the feed plate very close to the clips in the proximal area and also to use the space directly below the feed plate for the feed device. Despite this very compact arrangement, the spring-loaded tabs on the clips can slide past the underside of the clips when the feed plate is retracted, as they can dip into the free spaces of the feed device and thus have enough space to avoid the clips sliding past them. Overall, this results in a particularly compact arrangement.

It is advantageous if the rod has a circular cross-section and if the lateral projection and the recesses are formed by circumferential ring shoulders or ring grooves. With such a design

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the edge of the downwardly projecting central area of the feed plate in the distal area of the feed plate penetrates into the cross-section of the circular rod, so that the rod can introduce the feed force directly into the feed plate at the front. Even with a very thin design of the feed plate, this results in a safe introduction of force without the risk of it buckling sideways.

It can further be provided that the feed device rests with a lateral projection on a resilient tab of the feed plate when pushed back, wherein the resilient tab is preferably arranged at the proximal end of the feed plate, so that the feed plate is pulled when pushed back.

It is advantageous if the lateral projections on the feed device are closer together than the corresponding points of engagement on the feed plate. This makes it possible to provide the feed device with a reciprocating movement that is larger than the step size of the clips stored in the magazine, but the feed plate is only pushed forwards and backwards by one step size of the clips. This is particularly advantageous if different handles are to be used for operating the feed device on the application instrument, which generate different feed movements for the feed device depending on their design.

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The feed plate can basically be part of the application instrument, but it is particularly advantageous if the feed plate is guided in the magazine so that it can be moved lengthways parallel to the guide of the clips, i.e. is part of the magazine. When inserting the magazine, which is preferably inserted laterally into a shaft of the application instrument, it is positioned so that the lateral projections on the feed device engage between the corresponding points of engagement on the feed plate, so that the feed plate is inevitably moved when the feed device is pushed forward and pulled back.

The clips can preferably be held in the guide of the magazine in a detachable clamping fit, so that the clips are carried along by the feed plate during its feed movement and moved forward by one step, but remain in this position when the feed plate is retracted and when the spring-loaded tabs on the clips slide elastically along the clips and spring back into the carrying position behind the respective clips.

The following description of preferred embodiments of the invention serves to explain in more detail in conjunction with the drawing. They show:

Figure 1: a longitudinal sectional view of a surgical clip applicator;

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Figure 2: an exploded perspective view of the shaft portion of the instrument of Figure 1;

Figure 3: a longitudinal sectional view of the magazine and the feed rod arranged below the magazine during the feed movement of the feed rod in the distal direction;

Figure 4: a sectional view taken along line 4-4 in Figure 3;

Figure 5: a sectional view along line 5-5 in Figure 3 and

Figure 6: a view similar to Figure 3 during the retraction movement of the push rod in the proximal direction.

The application device shown in the drawing comprises a handle 1 and a tubular shaft 2 which is held on the handle so that it can be rotated and released around its longitudinal axis and whose outer diameter is small compared to its length, for example the length can be 25 cm and the outer diameter 10 mm or less. Two jaws 4 of a pliers-shaped application tool are mounted on the free end of the tubular shaft 2 so that they can be pivoted around a common pivot axis 3 and can be opened and closed from the handle 1 via a locking mechanism arranged inside the tubular shaft. For this purpose the handle 1 is rigidly connected to a first branch 5, opposite which a second branch 6 is arranged.

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is pivotally mounted on the handle 1. This second branch 6 is connected in an articulated manner to a push and pull rod in the form of a sleeve 7, which extends through the entire tubular shaft 2 to the locking mechanism 8. By pivoting the branches 5 and 6 against each other, the jaws 4 of the application tool can be opened and closed, as is known with tubular shaft instruments.

Immediately adjacent to the application tool formed by the jaws 4, the tubular shaft 2 has an opening 9 extending over the front part of the tubular shaft, which extends in the circumferential direction over approximately 180°, so that the tubular shaft 2 in the region of this opening is closed off by a lower shell 10 only in the lower half of the tubular shaft, but is open on the upper side.

The opening 9 on the top of the tubular shaft 2 can be closed by a clip magazine 11 inserted into this opening 9, which essentially has an almost semicircular cross-section and which completes the cross-section of the tubular shaft 2 to form a full circle. This clip magazine 11 has a projection 12 on its proximal side closest to the handle, which dips slightly into the tubular shaft 2 immediately adjacent to the opening 9 and thereby engages under the edge delimiting the opening 9. At the front end, two lateral tabs 13 are formed on the side of the clip magazine 11, which engage in complementary recesses in the lower shell 10 and in

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In the assembled state, the end regions projecting inwards snap into corresponding grooves in the lower shell 10 (not shown in the drawing), i.e. in this area, the tabs 13 are elastically locked to the side walls of the lower shell 10. By inserting the projection 12 into the tubular shaft 2 and by this locking connection, the clip magazine 11 is securely attached to the tubular shaft 2, but this connection can be released again, since the snap connection can be released again by forcefully pulling the clip magazine off the lower shell 10.

The tubular shaft 2 extends into a grip sleeve 23 which is displaceable longitudinally on the handle 1 against the action of a spring 22 and which is part of a ball lock connecting the tubular shaft 2 to the handle 1. This grip sleeve 23, which is mounted longitudinally displaceably on the handle 1, fixes several spherical locking bodies 24 which can be displaced in radial openings in the handle in a radially inward position when the spring 2 is relaxed, but it enables a radial outward movement of this locking body 24 when the grip sleeve 23 is retracted against the action of the spring 22. In the radially inserted position, the locking bodies 24 extend into radial recesses in the tubular shaft and fix it to the handle in the axial direction, but in their radially outward position the locking bodies 24 release the tubular shaft 2 so that it can be pulled out of the handle 1 in the axial direction.

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The sleeve 7 arranged in the tubular shaft 2 passes through the connection point between the tubular shaft 2 and the handle 1 into the handle and is there connected to the branch 6 in an articulated manner via two lateral pins 28 which engage in lateral openings 29. When the branch 6 is pivoted relative to the branch 5, the sleeve 7 is thereby pushed forward into a distal position and back into a proximal position.

It is cut open at the top in the area of the opening 9 of the tubular shaft 2, so that in this area it only forms a lower shell, which is firmly connected at its free end to a sliding block 30, which fills the cross-section of the lower shell 10 and is mounted in it so that it can be moved longitudinally. This sliding block 30 is connected in an articulated manner to a jaw 4 of the application tool via a connecting lever 31, so that a jaw 4 and a connecting lever 31 form a toggle lever (Figure 2). This toggle lever can be bent more or less strongly by pushing the sliding block 30 forwards and backwards, whereby the jaws 4 pivot. When the sliding block 30 is pulled back, the jaws 4 open again. This opening is also supported by a helical spring 32 which coaxially surrounds the sleeve 7 and is supported at one end on a projection of the lower shell 10 and at the other end on an annular shoulder 33 which is permanently connected to the sleeve 7. This forces the sleeve 7 towards the handle 1.

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subjected to a spring force which supports the opening of the jaws 4.

The locking mechanism 8 comprising the sliding block 30, the connecting levers 31 and the rear part of the jaws 4 is completely housed in the lower shell 10 and thus leaves the entire opening 9 free to accommodate a feed mechanism for the clips 35 and to accommodate the clip magazine 11 in which the clips 35 are located.

In the clip magazine 11, a receiving chamber 36 for the clips 35 is arranged, which is open at the bottom and has the shape of a longitudinal groove in the clip magazine 11. In the side walls of this receiving chamber 36, guide grooves 38 are let in opposite directions, into which the legs 39 of the U-shaped clips 35 dip. Several of these U-shaped clips 35 are arranged one behind the other in the receiving chamber 36, whereby they maintain a distance relative to one another (Figure 2).

Parallel to the guide grooves 38, a further guide groove 37 runs in each of the side walls, and in these a flat feed plate 40 is held in a longitudinally displaceable manner, which extends over the entire length of the clip magazine 11 and closes off the receiving chamber 36 at the bottom. This feed plate 40 has a distal section 41 adjacent to the jaws 4 and a proximal section 42 facing the handle 1, which in the embodiment shown

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play are approximately the same length, i.e. each extend over half the total length of the feed plate 40.

In the distal region 41, the central region 43 of the feed plate 40 is deformed downwards in the manner of a reinforcing bead, so that the plane spanned by the flat central region 43 is offset from the plane spanned by the guide grooves 37 (Figure 4). In the proximal section 42, however, the corresponding central region 44 is deformed upwards, i.e. in the direction of the clips 35, so that the flat central region 44 is offset upwards from the plane of the guide grooves 37 (Figure 5). As a result, the proximal central region 44 lies directly on the underside of the clips 35, while the distal central region 43 is spaced from the underside of the clips 35.

Both in the distal central region 43 and in the proximal central region 44, several spring tabs 45 are formed by longitudinal cuts, each of which is divided at its front end by longitudinal cuts into three spring tongues 46, 47, 48 arranged next to one another. The two outer spring tongues 46, 48 are bent at an angle in the area of their free end towards the receiving chamber 36, so that the free edges run at an angle to the surface of the feed plate 40 and protrude upwards over this surface towards the receiving chamber 36.

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When the advance plate 41 is in a retracted, proximal position, these edges each rest against the bridge 49 of a clip 35 connecting the two legs 39, whereby the slanted edges ensure that even with a linear contour of the bridge 49, a secure attachment is achieved and the edges are prevented from slipping. The middle spring tongue 47 of the spring-loaded tab 45 rests against the underside of the clips 35, so that in this way the edges on the top side are also reliably prevented from sliding over the clips 35.

When the feed plate 40 is displaced in the distal direction, each pair of spring tongues 46, 48 takes a clip 35 with it and pushes it in the clip magazine 11 by the step size of the displacement of the feed plate 40 in the distal direction.

The frontmost clip 35 is pushed forward from the guide grooves 38 in the side walls of the receiving chamber 36 and enters guide grooves 50 on the inner sides of the jaws 4, which are aligned with the guide grooves 38 and adjoin them.

At its front end, the feed plate ends in a spring tongue 51, which is narrower overall than the feed plate 40. When the feed plate 40 is pushed forward, this spring tongue 51 enters between the jaws 4 and pushes the front clip 35 into the slightly downwardly inclined guide grooves 50 of the jaws 4 up to their front end. Due to the narrow

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spring-loaded design of the spring tongue 51 in the front part
This can easily be adapted to the slightly changed inclination
follow the guide grooves 50.

The clip magazine 11 essentially consists of a
upper, lid-like half-shell 16, into which the clips 35 and the feed plate 40 are inserted in the manner described. In Figure 2, these parts are shown separately from one another for better clarity.

During the return movement of the feed plate 40, the
spring-loaded tabs 45 along the following clips 35 until they are completely behind them again
and spring back up into the removal position
in which the edges rest against the bridges 49 of the clips 35. Simply by the forward and backward movement of the feed plate 41, a clip is inserted between the
Jaws 4 are inserted, which is then in the described
way by closing the jaws,
for example, to close a blood vessel. This takes place until the clip magazine 11 is empty, then
can easily replace a new clip magazine
of the emptied one and the activity can be continued.

The displacement of the feed plate 40 is carried out by
a push and pull rod 52, which is guided longitudinally displaceably inside the sleeve 7 and which is connected in an articulated manner to a pivoting lever 53 on the handle 1. Its
Swivel movement causes the push and pull rods

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ge 52 can be moved inside the tubular shaft and inside the sleeve 7.

The push and pull rod 52 has a circular cross-section and extends below the proximal central region 44 of the feed plate 40 over the entire proximal section 42. The push and pull rod 52 rests closely against the proximal central region 44 with its outer diameter.

At its free end, the push and pull rod 52 has a short section 54 with a smaller outer diameter, thereby forming a circumferential step 55 between the section 54 and the rest of the push and pull rod 52. When the push and pull rod is pushed forward in the distal direction, this step 55 rests against an edge 56 of the distal central region 43. This edge is formed in the transition region between the distal central region 43 and the proximal central region 44, which protrude on opposite sides from the plane spanned by the guide grooves 37.

In the proximal direction, the step 55 is adjoined by several circumferential annular grooves 57 in the push and pull rod 52, the distance between which corresponds to the distance between the clips 35 in the clip magazine 11. These annular grooves 57 form receiving spaces for the spring-loaded lugs 45, into which they can enter when they are pulled back into the proximal

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Position slide along the underside of the clips 35 and are thereby bent downwards.

In the area of the proximal end of the clip magazine 11, a further annular groove 58 is incorporated into the push and pull rod 52, adjacent to the annular grooves 57, which forms an annular step 59 at its distal end and which has a sliding surface 60 at its proximal end. When the feed plate 40 is pulled back into the proximal position, a spring tongue 61 at the proximal end of the proximal middle region 44 engages downwards in this annular groove 58 and rests with its free edge on the annular step 59, so that the push and pull rod 52 takes the feed plate 40 with it in the proximal direction during its proximal displacement movement. As a result, the feed plate 40 is pushed forwards and backwards by pushing the push and pull rod 52 forwards and backwards. When advancing in the distal direction, the force is transmitted via the step 55, which rests against the edge 56, while when retracting in the proximal direction, the force is transmitted via the spring tongue 61, which rests against the ring step 59.

The distance between the edge 56 on the one hand and the spring tongue 61 on the other hand is chosen to be larger than the distance between the step 55 and the ring step 59, so that the push and pull rod 52 can perform a larger forward and backward movement and yet the feed plate 40 can only be moved by one clip distance in the magazine in both directions.

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This allows adaptation to different feed movements of different handles.

The operative connection between the push and pull rod 52 on the one hand and the feed plate 40 on the other hand is detachable, since it is created solely by the immediate proximity of the push and pull rod 52 to the feed plate 40. This connection is therefore easily created when a clip magazine 11 is inserted into the tubular shaft 2, and is released again when the clip magazine 11 is removed from the tubular shaft 2.

The push and pull rod 52 is concentrically surrounded by a helical spring 62, which is supported on the one hand on a projection 63 of the tubular shaft 2 and on the other hand on a step 64 of the push and pull rod 52 and thereby moves the latter into the retracted, proximal position. The advance plate 40 is thus pushed forward in the distal direction against the effect of the helical spring 62, which is otherwise located inside the sleeve 7.

Claims (12)

1. Application instrument for U-shaped surgical clips with a magazine having a distal and a proximal end, in which a plurality of clips are mounted one behind the other in a guide so as to be longitudinally displaceable, with a feed plate on the underside of the magazine which rests on the rear of the clips by means of spring-loaded tabs and which can be pushed forwards and backwards by means of a feed device over at least one clip distance parallel to the guide of the magazine and in the process pushes the clips together towards the distal end of the magazine during the feed movement, characterized in that the feed device ( 52 ) acts on the feed plate ( 40 ) when it is pushed forwards at a point ( 56 ) which is at least half the length of the feed plate ( 40 ) away from the proximal end of the feed plate ( 40 ). 2. Application instrument according to claim 1, characterized in that the feed plate ( 40 ) has , in its region ( 41) arranged distal to the point of application (56 ) of the feed device ( 52 ), a downwardly projecting central region ( 43 ) which runs at a distance from the clips ( 35 ) guided in the magazine ( 11 ). 3. Application instrument according to one of the preceding claims, characterized in that the feed plate ( 40 ) has, in its region (42) arranged proximal to the point of application ( 56 ) of the feed device ( 52 ), an upwardly projecting central region ( 44 ) which runs close to the clips ( 35 ) guided in the magazine ( 11 ). 4. Application instrument according to one of the preceding claims, characterized in that the feed device ( 52 ) is a rod which is arranged under the feed plate ( 50 ) and can be retracted and advanced and which, when pushed forward, comes to rest with a lateral projection ( 55 ) on the edge ( 56 ) of the feed plate ( 40 ) which projects downwards from the plane of the feed plate ( 40 ). 5. Application instrument according to claim 4, characterized in that the edge ( 56 ) is formed by the downwardly projecting central region ( 43 ) of the feed plate ( 40 ). 6. Application instrument according to one of claims 4 or 5, characterized in that the rod ( 52 ) is arranged proximal to the lateral projection ( 55 ) close to the central region ( 44 ) of the feed plate ( 40 ) and has recesses ( 57 ) which form receiving spaces for the resilient tabs ( 45 ) of the feed plate ( 40 ) when the rod ( 52 ) is pushed back. 7. Application instrument according to one of claims 4 to 6, characterized in that the rod ( 52 ) has a circular cross-section and that the lateral projection ( 55 ) and the recesses ( 57 ) are formed by circumferential annular shoulders or annular grooves. 8. Application instrument according to one of the preceding claims, characterized in that the feed device ( 52 ) rests with a lateral projection ( 59 ) on a resilient tab ( 61 ) of the feed plate ( 40 ) when pushed back. 9. Application instrument according to claim 8, characterized in that the resilient tab ( 61 ) is arranged at the proximal end of the feed plate ( 40 ). 10. Application instrument according to one of claims 8 to 9, characterized in that the lateral projections ( 55 ; 59 ) on the feed device ( 52 ) are less far apart from each other than the corresponding points of attack ( 56 ; 61 ) on the feed plate ( 40 ). 11. Application instrument according to one of the preceding claims, characterized in that the feed plate ( 40 ) is guided in the magazine ( 11 ) parallel to the guide ( 38 ) of the clips ( 35 ) so as to be longitudinally displaceable. 12. Application instrument according to one of the preceding claims, characterized in that the clips ( 35 ) are held in the guide ( 38 ) of the magazine ( 11 ) in a releasable clamp fit.