ITPI20080076A1 - OCCLUSION DEVICE FOR VASCULAR SURGERY - Google Patents

Description

OCCLUSION DEVICE FOR VASCULAR SURGERY,

DESCRIPTION

Scope of the invention

The present invention relates to a device for occluding openings made in the walls of vessels, in particular arteries, for percutaneous endovascular procedures, or for the endovascular treatment of arterial / venous pathologies of a haemorrhagic, dilating or dissecting nature.

For example, the device can be used at the end of diagnostic procedures such as arterographs or coronary arteries, or endovascular interventional procedures, such as angioplasty or stenting, which require percutaneous puncture of an artery to position an introducer in the vascular bed; it can also be used to treat pseudoaneurysms, to embolize arterial or venous districts, or to incur dissection of arterial walls.

Technical problem - Notes on the known technique

Many diagnostic and therapeutic procedures involve percutaneous introduction of instrumentation or catheters through an access site consisting of an arterial breach. The introduction usually takes place through an introducer body, which remains in its position for the entire duration of the intervention or examination. At the end of the procedure it is necessary to remove the introducer from the arterial breach and stop the blood supply. A traditionally used procedure involves a first step of manual compression at the access site, usually between 15 'and an hour, during which the blood pressure at the access site is reduced to allow for initiation of a natural hemostasis process; a second phase of compression assisted by bandaging and / or by the application of a weight follows, so that the natural process of reconstruction of the arterial wall is completed. The overall duration of the procedure, during which the patient must observe absolute immobility of the affected limb, depends on the site used for the introduction of the catheter and the condition of the subject: for example, for a femoral access site in a patient with normal coagulation parameters, it lasts between eight and twelve hours.

Various drawbacks can occur with the described technique, due to movements and / or particular conditions of the patient, for example of a subject that has been coagulated due to a pathology or a treatment. The most frequent complications are bleeding, hematomas, pseudoaneurysms, and others. The milder cases are solved by prolonging the compression, for other cases a surgical intervention is necessary, with further risks and inconveniences, as well as prolongation of hospitalization times, and greater commitment of resources. There are also difficulties in the case of obese patients, in which the adipose layer between the skin surface and the site to be hemostatized makes the compression less effective.

Some alternative techniques recently introduced to mitigate these problems involve the use of:

- suturing means,

- closure means such as clips or plates of various types, - associations of the above.

These means, while reducing the treatment times on average, do not offer clear evidence of advantages, in particular of reducing risks for the patient. In addition to the aforementioned complications, the introduction of foreign bodies into the artery involves risks unknown to the traditional technique, such as thrombotic ischemia or embolism, sensitization, intolerance. Furthermore, mechanical closing devices require considerable skill and specialization on the part of the operator, and / or more than one operator, and / or ultrasound assistance. There are also systems based only on liquids, in particular collagens, which form clots involved in the normal mechanisms of coagulation; however, they are characterized by a slow haemostasis process, which favors complications such as blood suffusion, haemorrhages or pseudoaneurysms.

In addition to biological compatibility, it is essential that the haemostatic fluid acts quickly, forming a closure medium with adequate flexibility and strength. Above all, in the case of endovascular interventions, it is important that the liquid arrives substantially undiluted in the intervention area, i.e. in a state of maximum reactivity, so that it solidifies in this area without being transported to remote vascular districts where it can harden causing embolisms and thrombosis.

Liquids of this type, such as fast-acting surgical glues for internal use, have not so far found application in hemostasis of arterial breccias and in percutaneous endovascular interventions, for three fundamental reasons.

In the first place, the devices that can be used to deposit small quantities of liquid in the vicinity of a site to be haemostatized necessarily include ducts with outflow sections as narrow as needles in the case of fillings of arterial breaches and catheters in endovascular interventions; the liquid can solidify when it comes into contact with blood already in the duct, blocking the device.

Secondly, and also for this reason, it is very difficult to lay pure a particularly reactive hemostatic fluid in an intervention area where there is blood under pressure. The methods that use rapid consolidation surgical glues resort to dilution, but this prolongs the consolidation time, considerably increasing the risk of distant embolization, as already mentioned.

Thirdly, with the means available it is difficult to prevent such a hemostatic fluid from being introduced into the vascular system, with the risk of thrombosis and embolism, in particular, in the case of occlusion of an access site for a catheter. , Instrumental assistance is required, in particular ultrasound.

Summary of the invention

It is therefore an object of the present invention to provide an occlusion device for vascular surgery, in particular for hemostasis of arterial breccias, such as catheter access sites, or for endovascular interventions such as occlusion of vessels or treatment of pseudoaneurysms, which uses a rapid hemostatic fluid action, for example a glue or a polymerizable substance, without this liquid hardening prematurely in the device causing it to block.

It is therefore also an object of the present invention to provide such a device that allows to bring such a hemostatic liquid into a vascular district for an endovascular intervention in a substantially undiluted state, so as not to compromise its rapid consolidation characteristics and to guarantee quantitative reaction of the liquid. in the area designated for the intervention, without dissemination in remote districts.

It is likewise an object of the present invention to provide such a device which reduces the risks of hemostatic fluid entering the artery through an arterial breach to be hemostatized, without using ultrasound or radiographic means.

It is also an object of the present invention to provide such a device which can be operated in a simple way by a single operator.

These and other purposes are achieved through an occlusion device for vascular surgery, capable of depositing a dose of a haemostatic liquid in a predetermined intervention area adjacent to a vessel or intravascular; the haemostatic fluid is designed to create an occlusion in the area of intervention such as to prevent the passage of blood. The device includes:

- a container of haemostatic fluid,

- a duct with an inlet and an outlet, to convey an outflow of the haemostatic fluid between the container and the intervention area,

- means to cause an outflow of the hemostatic fluid through the duct.

The main feature of the device is that it includes means for retaining a barrier liquid in the duct, such that the barrier liquid is interposed between the haemostatic liquid and the outlet, and in such a way that the barrier liquid is first dispensed from the outlet. , and then dispensing the hemostatic fluid, so that the hemostatic fluid is dispensed substantially undiluted.

In particular, the duct is chosen from:

- a needle, used for example in the hemostasis of arterial breccias, pseudoaneurysms or small aneurysms,

- a catheter, to reach sites to be haemostatted distant from the access site, through a path inside the arterial / venous system.

The device avoids contact of the haemostatic fluid with the blood inside the duct or near the outlet, thanks to the barrier liquid retained in the duct; in particular, this makes it possible to prevent a hemostatic liquid particularly reactive with the blood, or with other fluids present in the intervention area, from hardening by obstructing the duct before depositing the dose in the intervention area.

Furthermore, the barrier liquid cannot move away from the duct except when the means to hold it are removed or opposed, which facilitates the operator in positioning the duct until reaching the intervention area near the external wall with the exit. inside a vessel, without being affected by the effects of blood pressure: in fact, the retained liquid acts as a whole with the duct and the other parts of the device; in particular, there can be no counter-flow or recall of blood during the positioning phase of the duct.

Finally, during the injection inside a vessel in which there is blood flow, the barrier liquid, which arrives first, is washed away from the blood and therefore, upon arrival of the haemostatic liquid, the properties of rapid interaction of this with the blood are substantially unchanged, ensuring that this interaction is locally exhausted.

Advantageously, the device has available in the container a dose of a particularly reactive haemostatic liquid, i.e. capable of interacting substantially instantaneously with the blood and / or other biological liquids and / or other tissues present in the vicinity of the intervention area, creating occlusion; in particular, the hemostatic fluid is chosen from:

- a surgical glue for internal use,

- a preparation containing a cyanoacrylate, preferably selected from N-butyl-2-cyanoacrylate and 2-octyl-2-cyanoacrylate.

These compounds are monomers, i.e. polymerizable substances, successfully used in the reconstruction of continuity of injured tissues, for their high compatibility with biological tissues and for the good flexibility of the polymers they form in situ: the device according to the The invention allows the use of substances with similar behavior, in particular preparations based on cyanoacrylates for internal use, thus exploiting their advantageous characteristics also to carry out percutaneous endovascular interventions, such as embolization of vessels, treatment of cerebral malformations or small aneurysmal pathologies such as cerebral, arterial dissections, arteriovenous and other malformations, as well as to hemostatic arterial breccias upon removal of a catheter introducer. In particular, in the latter case, the cyanoacrylates rapidly combine, in addition to the blood, also with other biological fluids present locally, consolidating the periavventitial tissues and the surrounding fat, effectively gluing these materials on the artery wall. , and forming near the breach a real external plug, stably adhered to the wall and consisting of a conglomerate, that is a matrix of acrylic polymer incorporating the aforementioned biological materials. The rapid formation of the conglomerate blocks the outflow of blood allowing the normal repair processes of the arterial wall to be carried out autonomously from the conglomerate, no longer disturbed by the passage of blood through the arterial breach. Substances such as cyanoacrylates therefore provide an innovative occlusive system compared to known systems, which instead form plugs or clots involved in normal coagulation mechanisms, with the possible complications highlighted above.

Advantageously, the device comprises an assigned quantity of a barrier liquid available in a container selected from:

- an additional container, connected in use with the duct and equipped with outflow means,

- said duct equipped with frangible or removable end seals.

The barrier liquid is preferentially chosen from

- a physiological solution or other solutions,

- distilled water,

â € “a contrast liquid.

This is in favor of safety as it limits the possibility of errors in choosing the barrier liquid at the time of use, as well as allowing greater ease of use of the device.

The further container can have an inlet and an outlet, preferably with connection means respectively to the device container and to the conduit; the attachment means are preferably provided with seals which break when the connection is made. Advantageously, the additional container is available in sizes depending on the barrier liquid requirement, which varies according to the distance of the intervention zone from the device.

The conduit enclosing the barrier liquid can be a needle with the inlet equipped with a breakable seal for coupling with the container, and with the outlet equipped with a manually removable seal, for example a fragile portion of the end of the needle .

The use of a contrast liquid as a barrier liquid allows the use of radiographic means to visualize the selected point for depositing the hemostatic liquid, since the surgical glues are not visible in the scan. On the other hand, not all vascular districts are visible ultrasonographically due to the presence of air or bone, making many interventional procedures under ultrasound assistance, for example at the thoracic, abdominal or cerebral level, impractical. Many surgical glues, in particular those based on cyanoacrylate, are however visible ultrasonographically and therefore can be used under ultrasound when possible, using for example physiological solution as a barrier liquid.

Advantageously, means are provided for causing the outflow of the barrier liquid which can be operated independently of the means for causing the outflow of the haemostatic liquid. This facilitates the operator in the positioning phases of the duct retaining the barrier liquid, since he should exert a force to counteract the blood pressure and / or various frictions, but without initiating the delivery of the haemostatic liquid until the positioning It is accomplished. In order to avoid accidental activation of means that cause the outflow of the haemostatic fluid, in this case a protection is preferably provided to prevent accidental activation of the means for causing the outflow of the haemostatic fluid.

Advantageously, means are provided for blocking the outflow means, which prevent retrograde movement of the outflow means.

Preferably, seals are provided to isolate the barrier liquid from the haemostatic liquid in respective containers or in the duct; the seals are suppressed by activating the means to cause the outflow of the barrier fluid and / or the haemostatic fluid, and / or by connecting the conduit with a container of the device. In this way it is avoided that the liquids are mixed before an application of the haemostatic fluid, with loss of effectiveness of the haemostatic fluid.

In a preferential embodiment, the device is a double syringe as per claim 7, represented in figures 8 to 9, and described below. The duct, if necessary for example a needle or a catheter, is connected to the outlet shank of a compartment of the double syringe, containing barrier liquid, preferably supplied together with the device; the connection means between this compartment and the duct are advantageously hermetic to the air inlet. The barrier liquid is moved into the duct before it is positioned close to the intervention area, for example an access site for catheterization or a site reachable via an endovascular path. The displacement of the liquid takes place by operating on a piston which, once filled, is blocked in the position reached by a block, thus preventing both the liquid barrier from escaping from the duct and the entry of blood or other during the positioning of the duct; at the same time, the container with the haemostatic fluid is put in communication with the duct by breaking a seal, making the haemostatic fluid immediately available for administration, once it reaches the area of the operation. This embodiment has the advantage of constituting a device ready for use, which overcomes problems of interaction of the haemostatic fluid with biological fluids, consequent blocking of the device, dilution of the haemostatic fluid, simplification of the operator's maneuvers, in particular, to avoid the presence of air in the duct.

In particular, the intervention area is an access site in a vessel, in particular in an artery, engaged by an elongated body, in particular a substantially cylindrical introducer for catheterization; the duct is preferably flexible and has a portion fixed to a slide which can engage an external surface of the elongated body; the slide, striking the external wall of the vessel, indicates to an operator that the outlet of the duct is in a position that allows the dose of the haemostatic fluid to be deposited near the site. This allows to avoid deposition of hardenable material inside the vessel, limiting the risk of embolism and thrombosis, without requiring ultrasound assistance.

Furthermore, the association of the sled with the surface of the introducer or of the body allows for ease of use of the device since an operator, with one hand and therefore with limited request for coordination of movements on distinct limbs, can slide the slide as indicated above, stopping when it perceives an obstacle to further advancement, and acting with a finger of the same hand on means that control the outflow of the haemostatic fluid, causing its deposition in an external proximity to the site. In the short time that elapses between the deposition of the dose of haemostatic fluid and the formation of the conglomerate, the entry of haemostatic fluid into the vessel, in particular into the artery, is prevented, as well as by the introducer which engages the access site, from the blood pressure inside the vessel; the characteristics of the haemostatic fluid, and the speed with which it interacts locally with the biological medium, prevent its dissemination into the tissues surrounding the access site.

Preferably, the slide is a substantially cylindrical quill with a longitudinal cut such that by mutual approach and compression of the quill and the elongated body it is possible to make the quill embrace the elongated body stable while maintaining the relative sliding. The sleeve is therefore applicable at the end of the procedure and allows to occlude the arterial breach caused by the removal of the introducer, with considerable ease of use of the device.

Preferably, the duct has a blunt front end according to the direction of approach, and the outlet is located laterally to the duct. In this way, the advancement of the duct between the tissues that must be crossed in order to reach the external proximity of the artery seat of the arterial breach to be hemostatized is favored, without the risk of obstruction of the exit. The liquid barrier comes out through a lateral opening, in order to distribute the glue immediately above the arterial breach, in correspondence with the tissues to be glued to the arterial wall to create the plug.

The purposes indicated above, and others, are also achieved by an occlusion method for vascular surgery, in particular interventions to occlude openings made percutaneously in the wall of vessels, in particular of arteries, or percutaneous endovascular interventions; the method includes the steps of:

- preparation of a dose of a haemostatic fluid, - transfer of the dose in the distality by means of tubular transfer means,

- deposition of the dose in the vicinity of the arterial site.

The main feature of the device is that it also includes the phases of:

â € “preparation of a dose of a barrier liquid compatible with the biological environment contiguous to the arterial site;

- introduction of the barrier fluid into the duct prior to transfer, so that the transfer occurs without contact of the haemostatic fluid with the blood within the duct.

Advantageously, the haemostatic liquid is able to interact substantially instantaneously with the blood and / or with other tissues present in the vicinity of the intervention area, creating said occlusion. In particular, in the case of hemostasis of an access site in a vessel, in particular in an artery, the tissues surrounding the vessel, in particular fat, periavventitial tissue and others, wet by leaked blood or biological fluids present in the site. they are consolidated and adhered to the arterial wall creating a plug consisting of a conglomerate of haemostatic fluid with the aforementioned biological materials prevents the leakage of blood.

Preferably, the haemostatic liquid is selected from the cyanoacrylate family, in particular between 2-octyl-2-cyanoacrylate and N-butyl-2-cyanoacrylate.

Brief description of the drawings

The invention will be illustrated below with the following description of its embodiments, given by way of non-limiting example, with reference to the attached drawings in which:

- figure l shows a device according to the invention engaged in a closure operation of a percutaneous arterial access site;

- figure 2 shows a duct part of a device according to the invention, suitable for a closure operation of a percutaneous arterial access site;

- figure 3 shows the duct of figure 2 mounted on a catheter introducer;

â € “Figures 4â € ™ to 4â € â € ™ show a sequence of operations for closing an arterial access site with a device comprising the duct of Figures 3 and 4;

â € “Figures 5â € ™ to 5â € â € ™ show a sequence of operations for the treatment of a pseudoaneurysm with a device in figure 1;

- figure 6 shows an intervention for the treatment of a pseudoaneurysm of a different type using the device of figure 1;

â € “figure 7 schematically shows an operation involving the embolization of a vessel by means of a device according to the invention;

- figure 8 shows a double syringe according to the invention, alternative to the syringe shown in the previous figures;

â € “figures 9â € ™ -9â € â € ™ show the operation of the double syringe of figure 8.

Description of preferred embodiments

Figure 1 shows an embodiment 100 of the occlusion device according to the invention, engaged in a hemostasis operation of an access site 1 in an artery 2, crossed by an introducer for catheterization 20. The device 100 is capable of depositing a dose of a hemostatic fluid particularly reactive with blood or other biological fluids, typically a preparation based on cyanoacrylates, in an intervention area 6 close to the access site 1, creating an occlusion that prevents leakage of blood from access site 1 after removal of introducer 20. Device 100 includes:

- a syringe 101 composed of a piston 4 and a cylinder 5, which define a container 3 in which the dose of hemostatic fluid is arranged; the cylinder 5 has a base 14 opposed to the piston 4 with a through hollow shank 12, such as to allow the haemostatic fluid to escape, and the opposite base surmounted by a grip portion 11 which facilitates the handling of the syringe 101, or provides support to the protective cap 27;

- a duct, in particular a needle 7, having an inlet 8 and an outlet 9, for conveying an outflow of the haemostatic fluid between the container 3 and the intervention zone 6; the piston 4 provides means for causing such an outflow. A quantity of barrier liquid, for example a physiological solution, is prepared in needle 7, enclosed between seals not shown that block orifices 8 and 9. In particular, the seal on outlet 9 can be removed manually, while the seal on the inlet 8 is broken by the coupling of the needle 7 with the tang 12. The piston 4 has a portion, for example the sealing portion 10, which offers a stop to the locking means 13 fixed internally to the cylinder 5, therefore it cannot withdraw from a pre-established initial position. In this way, the physiological solution cannot go up into the duct due to the advancement in the tissues 30 and under the pressure of the blood, in particular in an artery, allowing an operator to position the device 100, operating on the portion of socket 11 or on the cap 27, with the outlet 9 in the intervention area 6, without contact of the blood with the haemostatic fluid before and during the initial phase of delivery; the haemostatic liquid is then dispensed by pushing the piston 4, and reaches the intervention zone 6 substantially undiluted. As an alternative to the blocking means 13, in order to avoid counter-flow of barrier liquid, a seal, not shown, can be provided, which occludes the orifice in the shank 12, and which breaks when the haemostatic liquid enclosed in the container 3 is pressurized by pushing the piston. 4.

With reference to figures 2 to 4, an embodiment of the device for occlusion operations of arterial access sites is described, and its operation. The device again comprises the syringe 101 of Figure 1, and a flexible conduit 85, which has a barrier liquid enclosed between two seals which close the inlet 84 and outlet 86 orifices.

In particular, the first seal is broken by engaging the inlet orifice 84 with the shank 12 of the syringe 101 making a sealed connection, for example by means of luer-lock fittings. As in the case of figure 1, the barrier liquid enclosed in the duct 85 then comes into contact with the haemostatic liquid present in the container 3, however the mixing is negligible taking into account the small size of the interface between the two liquids and the short time that elapses between the breaking of the seal on the inlet 84 and the deposition of the dose in the intervention area 6.

The flexible conduit 85 is fixed to a slide, in particular to a sleeve 81, which can slidingly engage the substantially cylindrical outer surface 35 of an introducer 20 for catheters (Figure 3). The quill 81 can also have a longitudinal cut 91 which allows the operator to hook the quill 81 to the introducer 20 at the end of a percutaneous intervention, simply by approaching and compressing it on the introducer 20 along the cut 91.

The operator then slides the sleeve 81 along the surface 35 by acting with one hand on the gripping portion 11 or possibly on the cap 27 of the syringe 101 (Figure 1). During the flow, the barrier liquid is stably retained in the duct 85: despite the arterial pressure, it cannot flow back towards the cylinder 5 thanks to the blocking means 13 (figure 1), as already described. Furthermore, the protective cap 27 prevents accidentally operating the piston 4.

The tube 81 has a front surface 82, which impacts against the wall of the artery 2 at a point 89 (figure 4 ") close to the access site 1. The position of the outlet 86 is such that, when it occurs the impact, the haemostatic fluid expelled from the outlet 86 is released just above the arterial opening 1. Upon impact, the operator stops the sliding of the sleeve 81 and acts, for example with the same hand, on the piston 4 to cause the outflow of the barrier liquid contained in the duct 85 and then the haemostatic fluid 32 from the outlet 86; at the end, the operator extracts the introducer 20 and the duct 85, and exerts a manual compression 26 (Figure 4â € â € ™ on the cutaneous level 29 above zone 1, for a few minutes. A conglomerate 31 of hemostatic fluid 32, blood, other liquids and tissues, in particular fat 33 is formed; this conglomerate adheres to the surface of the vessel 2, and occludes the access site 1. The hemostatic fluid 32 also seals the cavity left in the tissues 30 crossed by the introducer upon its removal.

Thanks to the duct 85 integral with the slide 81, the risks of deposition of hardenable material inside the vessel 2 are limited, without requiring ultrasound assistance.

The duct 85 preferably has a front end 93 (figure 2) closed and blunt so as to favor the advancement of the duct between the tissues, according to the direction 90 as it approaches the access site; likewise, the front surface 82 is rounded, that is, it has a convexity 92 always in the direction of 90 to avoid damaging the artery 2 at the moment of impact. the outlet 86 is arranged laterally to the duct 85, thus limiting the risk of obturation by the tissues 30 crossed during positioning. Similarly, the slide has a convexity 87, and a connection 88 with the duct 85, to facilitate the extraction of the slide and the duct at the end of the operation.

With reference to figures 5â € ™ to 5â € â € ™ and 6, the use of the device 100 to treat a pseudoaneurysm without collar 15 or with collar 25 (figure 6) is described, i.e. formations delimited by tissue 30 surrounding vessels 17 and 37, pulsating blood 28 (figure 5â € ™) that enters and exits through a direct access 18, or a collar 19. In the first case, the procedure involves a compression 21 of the skin plane 29 above the vessel upstream of the pseudoaneurysm 15 , and then a compression on the cutaneous plane 29 above the pseudoaneurysm 15 until it collapses completely on the wall of the vessel 17 (figure 6â € ™), after inserting a needle 23 which lets blood flow out of the aneurysm avoiding the rupture of the compression walls. Therefore, preferentially under ultrasound assistance, the device 100 is guided through the tissues 30: since the needle 7 is stably filled with physiological solution, and the piston 4 cannot retract, thanks to the locking means 13 previously described, or to means equivalent to them, there can be neither entry nor early contact of blood or other biological liquid with the haemostatic fluid, thus preventing solidification within the needle 7 and blocking of the device 100; for the same reason, the haemostatic fluid is deposited pure in the collaborated pseudoaneurysm 15, where it reacts quantitatively to give a conglomerate with the local tissues such as to close the access 18, without dissemination in the vessel 17 or in the tissues 30. Obviously, the release follows of the compression 21 on the skin level 29; what remains of the pseudoaneurysm 15 is naturally absorbed over time.

Similarly, in the case of the pseudoaneurysm with collar 25 (Figure 6), the procedure involves compression 21 to block the blood supply through the collar 19; preferably, a dose of haemostatic liquid is deposited in the collar 19 to definitively occlude it; the pseudoaneurysm 25 is then aspirated percutaneously, and the results of the unsupplied swelling, left in place, are then reabsorbed in a natural way. In this case it is even clearer how the haemostatic fluid must react quantitatively in the collar 19 or in the aneurysm 25, to prevent it from entering the vessel 37 and hardening, embolizing remote vascular districts; this is possible if the particularly reactive hemostatic fluid reaches the intervention area substantially pure, as made possible by the device according to the invention.

The syringe 101, in the various embodiments, can be supplied with the dose of haemostatic fluid already available for use.

As shown in Figure 7, a device such as the one described above, formed by the syringe 101 and a catheter 41 available filled with liquid, or filled in use with barrier liquid, can be used to embolize a vessel 40. In this case the flexible conduit 41 is carried through a vascular path with outlet 49 within vessel 40, under ultrasound or radiographic assistance. As in the case of Figure 7, the haemostatic fluid must react quantitatively in a determined area of the vessel 40 in order not to have entrainment and dissemination of hardenable material in remote areas, with the associated risks. The quantity of barrier fluid is defined by the volume contained in the catheter 41 between the access site not shown and the area of intervention in the vessel 40, while the volume of hemostatic fluid is equal to an equal volume increased by that necessary for the embolization.

A variant embodiment of the device according to the invention comprises a duct, for example a needle 7 as in figures 1, 5 'and 6, or the duct 85 of figure 2, or a catheter, and a double syringe 201 shown in figure 8. It is formed by an internal syringe 50 and an external syringe 70. The internal syringe 50 comprises a piston 51 sliding with a seal inside a cylinder 52, which has a base 53 with an opposite frangible portion 54 to the piston 51. The external syringe 70 comprises a cylinder 72 and, as a piston, the internal syringe 50, sliding with a seal in the cylinder 72; advantageously, a cap 57 which prevents access to the piston 51, allows the internal syringe 50 to be operated as a whole, and at the same time prevents accidental operation of the piston 51 of the syringe 50 itself. The cap 57 is preferably operated by gripping a gripping portion 64. The base 73 of the cylinder 72, opposite the internal syringe 50, has a tang 74 which can be engaged with the inlet of the duct; the shank 74 has a through cavity 75 which allows the passage of liquid between the cylinder 72 and the duct, and a tip 76 turned towards the inside of the cylinder 72, capable of breaking the frangible portion 54 when the base 53 of the cylinder 51 approaches the base 73 of the cylinder 72, in a sliding of the syringe 50 within the cylinder 72 towards the base 73 of the latter. Advantageously, the tip 76 passes through the shank 74, and houses the through cavity 75 inside it.

The internal syringe 50, or a portion of the cylinder 52, not engaged by the piston 51, provides a container 58 for the haemostatic fluid, and the piston 51 provides means for causing an outflow of the haemostatic fluid towards the outside of the cylinder 52. The external syringe 70, i.e. a portion of the cylinder 72, not engaged by the syringe 50, provides a further container 78 for the barrier liquid, and the syringe 50, operable as a whole as a piston thanks to the cap 57, provides means for causing an outflow of liquid barrier towards the outside of the cylinder 72, which can be operated independently of the means to cause outflow of the haemostatic liquid. The breakable portion 54 keeps the hemostatic fluid and the barrier fluid separate in their respective containers, before use.

The double syringe comprises pairs of locking teeth 61/62, which intervene at the end of a stroke of the syringe 50 within the cylinder 72, locking the syringe 50 in this end-of-stroke position, in which the container 78 of the barrier liquid is substantially empty. Furthermore, a block 63 is provided (figures 9â € and 9â € ™), similar to the block 13 of the syringe 101, which prevents the piston 51 from moving back with respect to a predetermined initial position, moves doses away from the base 53. On the base of figures 8 to 9 ', the operation of a device comprising the double syringe 201 and a duct such as a needle 7 (figures 1, 5' and 6), a duct with slide or sleeve is now described sliding on an introducer (figures 3, 4 'and 4'), or a catheter 41 for percutaneous endovascular interventions (figure 11). The device is supplied with a dose of hemostatic fluid available in container 58, and a quantity of barrier fluid, such as saline, in container 78.

After hermetically engaging the duct not shown with the shank 74, an operator presses on the cap 57 so as to slide the internal syringe 50 inside the cylinder 52 (Figures 8 and 9â € ™), reducing the volume of the container 78 and causing passage of physiological solution from the container 78 through the cavity 75 in the duct connected with the shank 74. The quantity of physiological solution is sufficient to fill a portion of the duct or the entire duct as needed; the chamber 78 may have a normalized initial capacity, sufficient to fill ducts with a suitable length to reach remote intervention areas reachable through a vascular path with the barrier liquid solution.

When the container 78 has been almost emptied, i.e. at the end of the stroke of the syringe 50 within the cylinder 52, interference is created between the tip 76 and the flexible seal 54, which breaks, putting the chamber 58 in communication, containing the hemostatic fluid, with the duct. Almost simultaneously with the breaking of the frangible seal 54, the locking teeth 61 integral with the syringe 50 engage respective locking teeth 62, locking the relative position of the internal syringe 50 and of the cylinder 72 in this end-of-stroke position. In this way, the syringe 50 cannot retract in the cylinder 72 with respect to this position, and the barrier liquid which fills the duct cannot flow either forward or backward; moreover, the lock on the initial position of the internal piston 51 prevents the physiological solution, which entered into communication with the barrier liquid after breaking the frangible portion 54, from rising towards the container 58 under the pressure of the blood.

Furthermore, the hermetic coupling between the duct and the shank 74 prevents the entry of air, and therefore the barrier liquid is retained in the duct.

Therefore, the operator can easily position the duct until reaching the area of the operation with the distal outlet orifice, where the haemostatic fluid must be deposited, without the counterpressure of the blood in the vessels crossed (in the case of endovascular intervention) causes the piston to retract and blood to enter the duct. Thanks to the protection cap 57, the positioning of the duct in the patient's body takes place without the risk of accidental actuation of the piston 51, that is, without the risk of prematurely dispensing hemostatic fluid.

Once the operation site has been reached, the operator removes the cap 57 (figure 9â €) and can act on the piston 51, making the haemostatic fluid pass from the container 58 into the duct. At this point, at his discretion, the operator can cause the haemostatic fluid to flow after the barrier fluid through the duct, pushing the piston 51 towards the base 73 of the cylinder 72.

The above description of specific embodiments is able to show the invention from a conceptual point of view so that others, using the known technique, will be able to modify and / or adapt these specific embodiments in various applications without further research. and without departing from the inventive concept, and, therefore, it is understood that such adaptations and modifications will be considered as equivalent to the specific embodiments. The means and materials for carrying out the various functions described may be of various nature without thereby departing from the scope of the invention. It is understood that the expressions or terminology used have a purely descriptive purpose and therefore not limitative.

Claims (10)

CLAIMS 1. An occlusion device for vascular surgery suitable for depositing a dose of a hemostatic fluid in a predetermined area of intravascular intervention or adjacent to a vessel, said hemostatic fluid being able to create an occlusion in said area of intervention such as to prevent passage of blood, said device comprising: - a container of said hemostatic fluid, - a duct having an inlet and an outlet for conveying an outflow of said haemostatic fluid between said container and said intervention area, - means for causing said outflow of said haemostatic fluid through said duct, said device being characterized in that it comprises means for retaining a barrier liquid in said duct, so that â € “said barrier liquid is interposed between said hemostatic liquid and said outlet, and that - first delivery of said barrier liquid and then delivery of said hemostatic liquid takes place from said outlet, so that said hemostatic liquid is substantially undiluted. 2. A device according to claim 1, comprising a dose of a haemostatic liquid contained in said container, said haemostatic liquid being able to interact substantially instantaneously with blood and / or with other biological liquids and / or tissues present in the vicinity of said intervention area creating said occlusion, in particular said hemostatic liquid is chosen from - a surgical glue for internal use, - a preparation containing a cyanoacrylate, selected in particular from N-butyl-2-cyanoacrylate and 2-octyl-2-cyanoacrylate. A device according to claim 1, comprising an assigned amount of a barrier liquid available in a container selected from: - a further container, said further container being connected in use with said conduit, said further container having outflow means, - said duct equipped with breakable or removable seals, wherein said barrier liquid is preferably selected from: - physiological solution or other solutions, - distilled water, - a contrast liquid. 4. Device according to claim 1 in which means are provided for causing outflow of said barrier liquid in said duct which can be operated independently of means for causing outflow of said haemostatic liquid, in particular a protection being provided to prevent accidental operation of said means for causing said outflow of said hemostatic fluid. 5. A device according to claim 1 or 4, wherein means for blocking said outflow means are provided, such that a retrograde movement of said outflow means is prevented. 6. A device according to claims 2, 3 and 4, wherein seals are provided for isolating said barrier liquid from said hemostatic liquid in respective containers and / or in said duct, said seals being suppressed by actuating said means to cause outflow of said liquid barrier and / or of said hemostatic liquid and / or by connection of said duct to a container of said device. 7. A double syringe according to claims 5 or 6, comprising: - an internal syringe formed by a first sliding piston with seal inside a first cylinder, said first cylinder having a base with a frangible portion opposite said first piston; - an external syringe formed by a second cylinder and by said internal syringe sliding with seal in said second cylinder, said second cylinder having a base opposite said internal syringe with a tang, said tang having an outlet cavity, and a tip turned towards the inside of said second cylinder and able to break said frangible portion when said base of said first cylinder approaches said base of said second cylinder, wherein said internal syringe supplies said container of hemostatic fluid and said first piston provides said means for causing outflow of hemostatic fluid, wherein said external syringe provides said further barrier liquid container and said means for causing outflow of barrier liquid operable independently of means for causing outflow of said hemostatic liquid, wherein means are provided for mechanically locking said first syringe in an end-of-stroke position within said second cylinder and said first piston in a predetermined initial position within said first cylinder, wherein said frangible portion provides means for keeping said hemostatic liquid and said barrier liquid separate in said respective containers. 8. A device according to claim 1, in which said intervention zone is an access site in a vessel, said site being engaged by an elongated body, in particular a substantially cylindrical introducer for catheterization, in which said duct is preferably flexible and has a portion fixed to a slide adapted to engage an external surface of said elongated body, such that said slide can strike the outer wall of said vessel indicating to an operator that said outlet of said duct is ready to deposit said dose of said hemostatic fluid in proximity of said site. 9. A device according to claim 8, wherein said slide is a substantially cylindrical sleeve with a longitudinal cut such that by mutual approach and compression of said sleeve and of said elongated body it is possible to make said sleeve embrace said elongated body. 10. A device according to claim 8, in which said duct has a blunt front end according to said approach direction, said outlet is arranged laterally to said duct, and said slide has a convexity such as to facilitate the advancement and extraction of said introducer and said conducted.