ITRM20000593A1 - ENDOSCOPICAD TREATMENT DEVICE FOR PEDUNCULATED POLYPES. - Google Patents

Description

DESCRIPTION

The present invention relates to the field of digestive endoscopy. More specifically, it concerns a particular endoscopic technique which is the polypectomy of pedunculated polyps with a metal loop. According to this technique, the loop, which has a more or less varied circular shape, when open is passed over the head of the polyp until it reaches the peduncle of the polyp itself. When it is in this position it is tightened so as to make circular contact with the pedicle and then an electric current is passed. The final effect is the resection of the pedicle <'> of the polyp.

The use of this technique, however, can still present great difficulties for the following reasons.

The peduncle of the polyp is equipped with a certain number of arterial, venous, lymphatic, and nerve filaments.

The larger the peduncle of the polyp, the larger the vessels mentioned above are. During the pedicle cutting maneuver by electric current with a prevalently coagulative effect on the tissues or by mixed current, ie with cutting and coagulation effect, the vessels undergo an occlusion phenomenon due to the necrosis induced by the current. To achieve this, the current must be maintained for a sufficient time and the current must be of suitable intensity.

If these effects are not sufficient to occlude the arterial vessel, the most relevant danger is hemorrhage. The haemorrhage is mainly of the arterial type and if conspicuous in a short time; time makes the endoscopic field impractical.

Moreover, the unsuitable view of the endoscopic field also prevents the stump of the pedicle from which the blood comes out. If emergency endoscopic maneuvers have been in vain or impractical, the problem must be addressed by the surgeon. It is evident that the problem becomes relevant when the haemorrhage from polypectomy concerns an elderly subject for whom the operating risks are enormously more relevant.

It should be emphasized that, unfortunately, the largest polyps and with peduncles are found precisely in the elderly.

The endoscopic emergency maneuvers are in part the same as those used for the prevention of polypectomy haemorrhage. The most used are the adrenaline injection, the endoops and the endoclips. However, there remains the big problem of blood and clots that makes these techniques extremely difficult to the point of making them impossible when, with the passage of time and with the bleeding in progress, the amount of blood that accumulates in the lumen of the bowel is increasingly significant. and the function of the aspirator channel of the endoscope is reduced due to the presence of clots which, once aspirated, are able to obstruct it.

Another technique used during polypectomy bleeding is to grasp the bleeding stump with the same <'> loop that was used <'> for the polypectomy and hold it tight for five minutes. . This technique, however, requires great dexterity and decision-making by the operator because it must be started as soon as possible before the stump is no longer visible in the blood, also because after an electric shock the stump tends to retract. of bleeding in progress, when this is significant, are not easy to use and in any case require considerable operational skills.

In order to carry out the throttling of a pedunculated polyp endoscopically, overcoming the aforementioned problems, the use of a filament of material equipped with thermal memory which is constructed in the form of a noose, or of the small Greek letter "alpha", and sheathed in an extended and elongated conformation in a rigid and rectilinear support, which keeps it in this conformation. The wire regains the shape of an "alpha" loop when it is released from the straight support at a predetermined temperature.

As is known, certain alloys, such as for example a Nickel and Titanium alloy which goes by the commercial name of Nitinol, are equipped with thermal memory, that is, they are able to acquire a programmed shape, when they are exposed to a predetermined temperature.

Thus a filament of Nitinol that is programmed to take the form of an "alpha" loop at the temperature present in the colon, if it is brought to a low temperature, that is to say around zero, can assume a rectilinear shape, while it regains the shape of a loop to "alpha" when it is released from its rigid rectilinear support in the environment of the intestine, in correspondence with the peduncle to be throttled.

In the patent application cited above, it was envisaged that the nitinol thread was inside a closed tubular jacket which was able to follow the variation in the conformation of the same thread and was pneumatically inflatable, by introducing air through the sclerosis needle, to allow the operator to increase the tightness around the pedicle, when this had been harnessed in its loop, in order to ensure a perfect constriction.

The methods of use provided that the inflatable tubular shirt containing the nitinol thread was introduced into the operating channel of the endoscopic device through the distal ostium to be mounted on the sclerosis needle, after being extracted from its rigid container, with the endoscopic device still outside the human body. This is to avoid tearing the shirt by pushing it along the entire length of the endoscope.

Once the endoscopic device has been reinserted into the human body and reached the polyp peduncle up again. to intervene, the tubular shirt could be pushed out of the operating channel by means of the sclerosis needle so that the thread, being in an environment at the temperature of the colon and free from any impediment, resumed its original alpha shape making a halfway point around the stalk for which it was programmed.

In practice, however, this device has not given the desired results, highlighting numerous drawbacks which make its use completely impracticable.

A first problem concerns the throttling function: this was in fact linked to the formation of an air chamber around the filament, which had to compress the peduncle. But this does not actually happen because when inflating the tubular shirt, it always tends to slide either upwards or downwards, thus nullifying the pressure on the polyp's peduncle which, on the contrary, must be fixed and constant. On the rare occasions when throttling can be initiated, the pressure is never constant: sometimes it is enough to slightly stretch the polyp, when it is grasped with the polypectomy snare, which can be seen sliding the tubular shirt filled with air, towards the 'up or down along the axis of the polyp's peduncle, making the operation useless.

In addition, in short pedicle polyps, inflation of the bladder creates many difficulties for subsequent positioning of the polypectomy snare.

A second problem concerns the impossibility of controlling the speed with which the yarn forms the alpha loop.

In fact, in the described device, no means was provided for reducing the bending speed of the nitinol yarn. This means that when the loop wraps around the pedicle with excessive speed, it is very easy to lose contact between the shape memory device and the needle.

A third drawback lies in the fact that in the previous patent application it is necessary to first wrap the nitinol loop around the polyp peduncle and then inflate the pneumatic bladder to constrict the peduncle.

It is therefore a two-stage maneuver.

A fourth drawback lies in the fact that the operator has to insert the needle into the pneumatic jacket that wraps the nitinol wire and position everything at the distal end in the endoscopic device before introducing the device itself into the human body. This rather complicated preparatory phase was followed by the operational one. Also in this case, therefore, the operator's maneuver was foreseen in two stages, with evident waste of time.

The aim of the present invention is to obviate all the drawbacks described above, with the use of a shape memory device which has the following peculiar characteristics:

a) the device consists of a nitinol wire equipped with insulating means capable of eliminating the danger that during the polypectomy the same wire may transmit to the wall of the intestine - the current that runs through the metal loop that performs the pedicle resection; b) said device can be introduced into the endoscopic device after identifying the position of the pedicle to be treated, without the need to extract the same endoscopic device from the patient's body and this thanks to the combined use of a guide tube which is introduced into said endoscopic device and reaches its distal end, and by means managed by the operator able to push the same shape memory device from the proximal to the distal end of said guide tube making it come out of the endoscopic device; b) the use of said guide tube and of these means allows to position even more than one shape memory device, in succession, near the distal end;

c) means are provided for controlling the rate of formation of the loop or loops, and for grading the exit of the ends of each loop from the distal ostium of the endoscopic device;

d) the throttling takes place only with the aitinol thread which is preferably shaped in such a way as to form a loop of three millimeters: if it is wider, the widthz <'> z <'> a of the càppio <"> is <'> diminished <"> gives microspheres or glass beads described below.

In particular, according to a preferred embodiment of the invention, the device consists of an aitinol wire which is coated with an adherent, non-inflatable latex shirt, having only the function of insulating to avoid the danger that during the polypectomy the same wire may transmit fortuitously to the wall of the intestine the current that runs through the metal loop that carries out the resection; said jacket can also be micro-perforated for easier heat exchange.

There are two possibilities to control the speed of formation of the loop or loops in the environment of the bowel;

e) to inject cold water so as to hit the nitinol thread before its exit and thus avoid that the same thread has a violent snap when it comes into contact with the temperature of the bowel or that, bending prematurely, gets stuck in the distal section of the tube;

f} to insert on the nitinol wire a certain number of microspheres or glass beads or other suitable insulating material, suitably distributed along its entire length, which slow down the exit of the device from the guide tube. The presence of these beads, in addition to constituting a brake for the winding speed of the wire, also has the function of ensuring the insulation of the wire from a fortuitous contact with the metal loop crossed by current that operates the polypdomy. The beads can therefore be provided as an alternative to the latex insulating shirt or can be applied over the same shirt.

In summary, there are three types of nitinol devices: with only the insulating jacket, with only the beads or with the insulating jacket and the beads, and two types of expulsion systems: through the use of a common biopsy forceps that grasps the proximal tip of the shape memory device and manages its exit from the special guide tube, or the use of a push tube when more than one devices are positioned in the guide tube.

Further characteristics and advantages of the invention will become evident from the detailed description which follows with reference to the attached drawing tables which illustrate some preferred embodiments only by way of non-limiting example. In the drawings:

fig. 1 is an overall view of the shape memory lace, in the original construction conformation, i.e. in the form of a loop, according to a first embodiment, consisting of a nitinol thread, bearing a small ball at each end, inside a tubular sheath;

Figure 2 shows the same lace of Figure 1 in a rectilinear conformation;

Fig. 3 shows on a larger scale a portion of the lace of Fig. 2 with the sheath equipped with micro-holes;

Figures 4 and 5 show, respectively, in the original conformation with a loop and in a rectilinear conformation, a second embodiment where microspheres or beads of glass or similar material are inserted on the wire without the sheath;

Figures 6 and 7 show always in the original conformation with a loop and in a rectilinear conformation, a third embodiment with the wire which is equipped with both the sheath and microspheres or beads;

Fig. 8 schematically shows a first thrust device, to be used when several loops are present in succession in the endoscopic device;

figure 9 shows a second embodiment of the pin to be used if only one loop is used;

fig. 10 shows the nitinol thread as it begins to form the loop around the polyp's peduncle;

Fig. 11 shows the nitinol wire with the loop already closed.

With reference to the figures, according to a first preferred embodiment of the invention, the shape memory device is constituted by a nitinol thread 2, fixed at its ends to a pair of balls or pads 1, placed inside a shirt or sheath 3, preferably of rubber latex, having only the task of electrically insulating said wire.

As can be seen in fig. 3, preferably the jacket or sheath 3 is provided with microholes 4 which in any case ensure a correct heat exchange with the outside allowing a more rapid adaptation of the wire 2 to the intraluminal temperature.

Figures 3 and 4 show a second embodiment. In this case, a plurality of microspheres or beads 10, made of insulating material, of a much larger diameter than that of the wire but in any case smaller than that of the lumen of the guide tube which runs in the operating channel of the colonoscope, are inserted on the wire 2. Preferably, the microspheres 10 are made of glass, a material which has the advantage of not being conductive.

A third embodiment which combines the characteristics of the previous ones is illustrated in figs. 6 and 7. As can be seen in these figures, the microspheres or beads are threaded onto the sheath that wraps the nitinol wire.

As previously mentioned, once the nitinol wire 2 has been programmed to assume the lowercase Greek alpha form at the temperature present in the colon, it can be brought, before use, i.e. outside the human body, to a rectilinear shape by exposing it to low temperature.

In these conditions it is possible to introduce this wire in a rectilinear conformation, in a guide tube 7, of suitable diameter, so as to make it easily pass through the channel 12 of a colonoscope or other endoscopic device 14.

As can be seen in fig. 8, when the peduncle 9 of the polyp 16 has been reached with the endoscopic device 14, it will be sufficient for the operator to push the wire 2 with the programmed loop towards the outlet of the operator channel 12 of the endoscope 14, and this by means of a suitable pushing means which may be either a common biopsy forceps 6 able to hook the proximal tip of the loop, as seen in fig. 9, or another tube 5 coaxial to channel 7, but with a smaller diameter, shown in fig .8.

As the loop, pushed by the operator, comes out of the guide tube 7 which contains it and forces it into a rectilinear shape, the loop in the environment of the intestine takes on the alpha shape to which it has been programmed and in this movement will involve the pedicle of the polyp and strangle it. (Fig. 10)

When it comes out of the guide tube 7 and begins to bend, the nitinol loop is suitably guided both with movements of the endoscopic device and with movements of the forceps 6 which holds it still. The nitinol loop will make a turn around the pedicle, squeezing it in a vise and irreversibly blocking the blood flow. (Fig.11).

As mentioned, the tube 7 which contains in its distal portion the nitinol loop in a straight shape, can instead of the pliers 6 contain another tube 5, coaxial to it, which acts as a pusher. Said tube 5, which is empty, is equipped at its distal end with means suitable for pushing said shape memory device, and is pushed together with the tube 7 along the operating channel 12 of the endoscope.

The use of the tube 5 as a thrusting means is necessary when the shape memory devices are more than one, positioned in succession in the last centimeters of the tube 7, as can be seen in fig. 8.

In fact, the use of the pliers allows to guide only one device until it comes out of the guide tube 7.

It should be noted that said tube 5 allows to carry out, together with the thrust of the shape memory devices, also the injection of cold water, so as not to bend the same shape devices in the tube 7, thus avoiding that problems arise due to their coming out of the guide tube itself 7.

In this regard, it must be borne in mind that the presence of the glass beads is a further brake on the winding speed.

If, on the other hand, there is only one shape memory device, even if the latter will tend to bend in the guide tube that contains it, the biopsy forceps is more than enough to push it out of the tube, towards the pedicle where automatically it will wrap around. The biopsy forceps is obviously introduced in the same guide tube and holds the end of the wire with the nitinol loop bead tight between its valves in a straight position.

The noose that constricts the peduncle is of various sizes. The diameter of the loop of the loop varies in size in relation to the size of the peduncle to be throttled. The minimum diameter of the loop is 3 mm because a pedicle below 3 mm hardly bleeds when cut with a polypectomy snare.

The desired size can in any case be reached either by conforming the nitinol in this way or, if it is considered for technical needs, by making the loop larger and narrowing it with the use of glass beads 1, which are in any case compatible with the diameter of the cannula that it must contain them.

When the system of double coaxial tubes 5-7 is used to push the shape memory device, the glass microspheres 1, in addition to being stacked in the section of the nitinol wire which will then form the loop, must also be positioned in a minimum number of three along the two arms of the loop so as not to make them eject too quickly from the distal ostium of the endoscope, thus slowing down the winding speed.

When, on the other hand, the thrust tube 5 is used, it is in any case advisable for one of the two ends of the loop to be exuberant with respect to the other, so that, not being held by the pincer but only braked in its winding by the flow of cold water, it is not shots with excessive speed getting lost in the lumen of the intestine.

Claims (14)

CLAIMS 1) Shape memory device for the endoscopic treatment of pedunculated polyps, comprising a thread of material with a thermoprogrammable shape memory, able to regain the programmed shape of a loop in order to constrict the polyp's peduncle upon reaching of a predetermined temperature, characterized by the fact that it consists of a nitinol wire equipped with insulating means to avoid that during the polypectomy the same wire can accidentally transmit to the wall of the intestine the current that runs through the metal loop that carries out the resection of the peduncle; said device being able to be introduced into the endoscopic device already introduced into the patient's body and positioned on the pedicle to be treated, without therefore the need to extract it, and this thanks to the use of: a tube which acts as a guide to the same device in its extended configuration, and which is able to pass into the operating channel of said endoscopic device, reaching its distal end; and of: means managed by the operator able to push the same shape memory device, inside said guide tube, from the proximal to the distal end, making it come out of the endoscopic device itself. 2) Shape memory device for the endoscopic treatment of pedunculated polyps, as in the previous claims, characterized in that means are provided for controlling the speed of formation of the loop or loops, and for graduating the exit of the ends of each loop from the guide tube lumen. 3) Shape memory device for the endoscopic treatment of pedunculated polyps as per the previous claims, characterized by the fact that the device consists of a nitinol thread which is coated with an adherent, non-inflatable latex shirt, having only the function of insulator to avoid the danger that during the polypectomy the same wire could fortuitously transmit the current flowing through the metal loop that carries out the resection to the wall of the intestine; said jacket being also micro-perforated for easier heat exchange. 4) Shape memory device for the endoscopic treatment of pedunculated polyps, as in the previous claims, characterized by the fact that a certain number of microspheres or glass beads suitably distributed are inserted on the nitinol wire, which, in addition to constituting a brake due to the winding speed of the nitinol wire, they ensure the isolation of the file itself from accidental contact with the metal loop traversed by a current that operates the polypdomy. 5) Shape memory device for the endoscopic treatment of pedunculated polyps, as per the preceding claims, characterized in that the throttling takes place only with the nitinol thread, without the aid of air chambers. 6) Shape memory device for the endoscopic treatment of pedunculated polyps, as per the previous claims, characterized by the fact that said nitinol thread is preferably shaped in such a way as to form a loop of three millimeters: if wider, the width of the noose being diminished by microspheres or glass beads strung on said thread. 7) Shape memory device for the endoscopic treatment of pedunculated polyps, as per the previous claims, characterized by the fact that to push the shape memory device out of the guide tube and the endoscopic device from biopsy introduced in the same guide tube. 8) Shape memory device for the endoscopic treatment of pedunculated polyps, as per the preceding claims, characterized in that a ball or slub is fixed to each of the ends of the nitinol thread to facilitate gripping the valves of the biopsy forceps. 9) Shape memory device for endoscopic treatment of pedunculated polyps, as per the preceding claims, characterized by the fact that a coaxial tube inside the guide tube is provided as a thrust means. 10) Shape memory device for the endoscopic treatment of pedunculated polyps, as per the preceding claims, characterized in that to control the speed of formation of the loop or loops in the environment of the bowel, it is provided to inject cold water into so as to invest the nitinol wire before its exit from the guide tube and thus avoid that the same wire has a violent snap when in contact with the temperature of the viscera or that, bending prematurely, it becomes stuck in the distal section of the guide tube. 11) Shape memory device for the endoscopic treatment of pedunculated polyps, as per the preceding claims, characterized in that the injection of cold water takes place through said thrust tube which is empty. 12) Shape memory device for endoscopic treatment of pedunculated polyps as per the preceding claims, characterized in that the beads are applied over the latex shirt or sheath adhered to the nitinol thread. 13) Shape memory device for the endoscopic treatment of pedunculated polyps as per the previous claims characterized by the fact that one of the two ends of the shape memory device is longer than the other, so that, not being braked from the forceps, but only from the flow of cold water that controls its temperature, do not snap too quickly and get lost in the lumen of the intestine. 14) Shape memory device for the endoscopic treatment of pedunculated polyps, comprising a thread of material with a thermoprogrammable shape memory, able to regain the programmed shape of a loop in order to constrict the polyp's peduncle upon reaching of a predetermined temperature, as substantially described and illustrated in the attached drawing tables.