FR3009200A1 - INJECTION CANNULA OF A BIOCOMPATIBLE PRODUCT UNDER THE SKIN OF A PATIENT - Google Patents

Abstract

The invention relates to a cannula for injecting a biocompatible product under the skin of a patient, said cannula comprising a base (3) intended to be connected to a container of said product, and a rod (1) having a proximal end (1b) which is mounted on said base and a distal end (1a) which is equipped with at least one injection port (2), said cannula further comprising a sleeve (4) having a front end ( 4a) forming a sharp tip (7) to allow drilling of said skin, said sleeve being reversibly associated with said rod with the tip (7) extending beyond the distal end (1a), said sleeve being removable manually said rod after piercing said skin.

Description

The invention relates to a cannula for injecting a biocompatible product under the skin of a patient, as well as a method of injecting a biocompatible product by means of such a cannula in the context of an aesthetic intervention. .

It applies in particular to the injections of a filling product, in particular based on hyaluronic acid, under the skin of at least a part of the body of a patient, for example the face and / or neck of said patient , in order to temporarily remove the unsightly effects of aging of the skin, such as wrinkles and loosening of the skin, and / or to revitalize said skin by moisturizing the layers of the epidermis. It can also be applied to auto-transplant injections of organic products previously taken from the patient, such as fat or platelet-rich plasma (PRP), for purely aesthetic purposes and / or to correct unsightly effects due to trauma, such as after an accident or surgery. To perform such an operation, the practitioner generally uses an injection cannula which has a rounded distal end and at least one lateral injection port disposed near said distal end. Indeed, this type of cannula is particularly suitable for filling products, which are generally quite thick, and minimizes trauma to tissue and vessels deep layers of the skin, such as cysts, bruises, bruising or hypostases, as well as nervous traumas. During the procedure, the practitioner begins by piercing, with a needle having a sharp distal end, an area of the skin located not far from an area to be treated, to provide access to said area to be treated.

Then, the practitioner removes the piercing needle and introduced through the hole thus formed an injection cannula as described above, then slides under the skin said cannula until the injection port opens into the area treat. It then injects the product into the area to be treated via the cannula, the product being for example contained in a syringe or in another type of container on which the said cannula is mounted.

However, this type of technique is not entirely satisfactory, in that the hole formed by the piercing needle is sometimes difficult to identify, which can waste time for the practitioner.

In particular, to locate the hole, the practitioner may be forced to pinch the skin, sometimes several times, so as to cause bleeding through said hole, which can be painful for the patient and cause haematomas or swelling from the pinched area to bleeding. As a result, the patient's recovery is lengthened, and the presence of unsightly traces can be harmful to the patient, who is then forced to temporary eviction during the convalescence. Moreover, such a technique requires many manipulations of the piercing needle, in particular to insert and remove it from the skin of the patient, which increases the risk of accidental punctures for the practitioner as well as the risk of loss of sterility. of said needle. The invention aims to improve the prior art by proposing in particular an injection cannula allowing the practitioner to perform more easily and more quickly the injection of a product, while significantly reducing the risk of trauma to the patient. For this purpose, according to a first aspect, the invention proposes an injection cannula for a biocompatible product under the skin of a patient, said cannula comprising a base intended to be connected to a container of said product, as well as a a shaft having a proximal end which is mounted on said base and a distal end which is equipped with at least one injection port, said cannula further comprising a sleeve having a forward end forming a sharp tip to allow drilling of said skin, said sleeve being reversibly associated with said rod with the tip extending beyond the distal end, said sleeve being manually removable from said rod after piercing said skin.

According to a second aspect, the invention proposes a method of injection by means of such a cannula of a biocompatible product under the skin of a patient in the context of an aesthetic intervention, said method providing the steps of: piercing an area of said skin by means of the sharp tip of the front end of the sleeve; sliding of the stem of said cannula under said skin from said pierced zone until the distal end of said stem opens into an area to be treated; injecting the product into said zone to be treated via said cannula; said method providing for withdrawal of the sleeve from said rod after piercing said skin. Other features and advantages of the invention will appear in the description which follows, made with reference to the appended figures, in which: FIG. 1 a diagrammatically represents an injection cannula according to a first embodiment of the invention, Figure lb showing a top view of a front portion of Figure 1a; FIG. 2 diagrammatically represents an injection cannula according to a second embodiment of the invention. In connection with these figures, a cannula for injecting a biocompatible product under the skin of a patient is described below, as well as, in the context of an aesthetic procedure, a method of injection by means of such a cannula of such a product in at least one area to be treated located under said skin.

The cannula can also be used for the injection of a biocompatible product in the context of a medical or veterinary intervention, said product containing for example mainly anesthetic.

The cannula comprises a rod 1 which has a distal end 1a which is equipped with at least one injection port 2. In particular, the cannula has a distal end rounded near which the injection port 2 is located. Such a rounded end 1 not only makes it possible to avoid the section of blood vessels and nervous trauma during the introduction of the cannula under the skin of the patient, and thus to limit the trauma for said patient, but also to limit the risk of accidental puncture for the practitioner. Furthermore, the injection port 2 is disposed laterally near the rounded distal end 1a. In particular, the orifice 2 has a diameter of between 0.05 mm and 1 mm and is located at most 2 mm from the rounded distal end 1a. The cannula further comprises a base 3 intended to be connected to a container of the biocompatible product to be injected, for example a syringe or another type of container, the rod 1 having a proximal end 1b which is mounted on said base, for example in being fixed by means of an adhesive in a housing provided for this purpose on said base.

For example, the base 3 may be of Luer-Lock® or Luer-Slip® type, to be mounted respectively by screwing or by friction on the tip of a syringe, these types being advantageously universal to allow the use of the cannula with all types of syringes or other containers.

The cannula may also include a protective cap to be mounted on the base 3 by surrounding the rod 1, to ensure the protection and possibly perfect sterility of said rod before use.

Furthermore, the base 3 and the cap may be made of a polymer that is harmless to the human body, for example polypropylene or a polypropylene copolymer, especially ethylene-polypropylene. In general, the base 3 and the cap may be made of a non-flammable material, in particular without pyrogen. In the context of an aesthetic intervention, the biocompatible product may be a filling product, for example based on hyaluronic acid, to temporarily correct the unsightly effects of aging of the skin.

In particular, a product based on hyaluronic acid fluid can be used to smooth the skin to reduce wrinkles. Similarly, a product based on crosslinked hyaluronic acid, therefore thicker, can be used to restore volume to the skin and / or to stretch said skin, in order to counterbalance a relaxation due to a loss of elasticity of said skin and / or to correct an asymmetry, in the case where an area of the skin has a loosening and / or loss of volume greater than its symmetrical zone. The biocompatible product may also comprise an additive having anesthetic properties, for example based on lidocaine, in order to reduce the pain that the patient may feel during the injection, this pain being all the more important that the said product is thick. The product to be injected may also comprise an additive having antioxidant properties, for example based on mannitol, as well as vitamins for revitalizing the layers of the skin in the zone to be treated.

The biocompatible product may also be an organic product previously taken from the patient, such as, for example, fat or platelet-rich plasma (PRP), for purely cosmetic purposes and / or to allow injections in auto-grafts, in particular to correct unsightly effects due to trauma such as an accident or surgery.

The area to be treated can be located on the face or neck of the patient, especially on the parts of the face or neck most prone to unsightly effects of aging of the skin, such as wrinkles or loosening.

For example, the area to be treated can be located at a commissure of the lips (prone to "folds of bitterness"), at an outer corner of an eye (subject to wrinkles in "crow's feet"), on a temple , on the forehead, and especially at the level of the glabella (subject to "lion's wrinkles"), at an orbital zone (where dark circles and / or pockets may appear), the valley of tears (located under an eye) of a cheekbone or cheek (where loosening and / or loss of skin volume can be seen). The area to be treated may also be located on other parts of the body particularly subject to such aging effects, such as the hands, but also the arms, thighs, chest for women, especially at the neckline, or scalp. Depending on the biocompatible product to be injected and the desired aesthetic effect, the area to be treated may be located at various depths of the patient's skin. For example, for the correction of wrinkles, the area to be treated is generally located in a superficial layer of the skin, especially the epidermis or dermis. On the contrary, for the correction of a looseness of the skin, a lack of volume, and a possible resulting asymmetry, the area to be treated is rather located in a deep layer of the skin, especially the hypodermis. In particular, the area to be treated may be located in the stratum granulosum, that is to say the last layer of nucleated cells of the epidermis. The area to be treated may also be located under the epidermis, in particular between the dermis and the bone, and more particularly between the deep dermis and the periosteum of the bone. Before proceeding to the intervention, the practitioner can determine the zones to be treated by a careful examination of the patient, in particular by means of adapted lighting, to identify the possible lack of volume and the asymmetries which can result from it, but also for identify the blood vessels that should be avoided so as not to cause trauma to the patient.

This examination includes local observations but also a global observation, especially with regard to the face, in order to correct the unsightly effects in a harmonious way and thus to guarantee a natural result for the patient. Once the areas to be treated have been identified, the practitioner can mark them with a hypoallergenic pencil. Moreover, to limit the risk of infection, the practitioner can obviously take hygiene measures, especially before proceeding to the marking of the areas to be treated. To do this, the practitioner can clean the skin to remove any impurities, including makeup, and apply an antiseptic solution on said skin. The method provides for piercing an area of the patient's skin to provide an access hole to the area to be treated for the stem. To do this, the cannula further comprises a sleeve 4 which has a front end 4a forming a sharp point 7 to allow the piercing of the skin, said sleeve being reversibly associated with the rod 1 with the tip 7 extending beyond the distal end of said rod.

In connection with the figures, the tip 7 is integrally formed with the front end 4a and said front end is disposed around the distal end 1a, so that only said tip extends beyond said distal end . Alternatively, a portion of the leading end 4a may extend beyond the distal end 1a, the tip 7 extending from said portion beyond said distal end. According to another embodiment, the tip 7 may be attached, for example by overmoulding, on the distal end 1a, in particular being made in a material different from that of the sleeve 4.

The sleeve 4 is made of plastic material, in particular based on a polymer that is harmless to the human body. For example, the sleeve 4 may be made of polypropylene or a polypropylene copolymer, especially ethylene-polypropylene. In general, the sleeve 4 may be made of a non-flammable material, in particular without pyrogen. Furthermore, the association of the sleeve 4 to the rod 1 prevents the sleeve from moving relative to said rod during piercing of the skin. To do this, the sleeve has a rear portion 8 which is associated on the rod 1. In relation with FIGS. 1, the sleeve 4 has a length less than that of the rod 1 and a rear portion 8 of the said sleeve is associated, by example by gluing around the rod 1, said rear portion being located on the rear end 4b of said sleeve. FIG. 2 represents a variant in which the sleeve 4 has a length substantially equal to that of the rod 1 and comprises a rear portion 9 disposed in longitudinal support on the base 3, said rear portion being located on the rear end 4b of said muff. The area to be pierced may in particular be located on the patient's face, for example near an ear (retro-mandibular point), in a nasolabial area (at the level of the modiolus, mandibular point), at the level of the bone. zygomatic (zygomatic point), on a temple (temporal or frontal point) or 25 above the glabella (glabellar point). Thus, the practitioner can reach several localized treatment areas on the face and / or the neck of the patient from the same hole in said area to be pierced, which limits the drilling of the skin, and thus the trauma for the patient. In particular, for an intervention on the face, the number of zones to be pierced may be between two and four for each side of said face. The area to be pierced may also be located on the hand, an arm or a thigh, on the chest, especially at the neckline, or on the scalp.

To reach the area to be treated, after having pierced the skin, the method provides a step of sliding of the rod 1 from the pierced zone, until the distal end of said rod opens into said area to be treated. In particular, at least at the beginning of this sliding, the sleeve 4 can remain associated with the rod 1 to guide the introduction of said rod under the skin. Thus, the practitioner can save time compared to conventional injection techniques because he does not have to locate the hole formed by drilling, since the sleeve 1 that has been used in said piercing remains positioned in said hole at least during the introduction of the rod 1 in said hole. Therefore, the practitioner does not need to resort to traumatic practices for the patient, such as pinching the skin of said patient several times to locate the hole by risking bleeding. In addition, by guiding the rod 1 by the sleeve 4, the practitioner fumbles less during the introduction of said rod, which is also less traumatic for the patient. In addition, by using a sleeve 4 associated with the stem 1 rather than a conventional perforating needle, the practitioner limits the handling operations of a perforating instrument, which makes it possible to limit the risks of accidental puncture for said practitioner and the risk loss of sterility of said piercing instrument. Furthermore, the method provides for the removal of the sleeve 4 of the rod 1 after having pierced the skin and introduced the rod 1. To do this, the sleeve 4 is manually removable from the rod 1 after piercing the skin. In particular, the sleeve 4 is arranged to be manually deformed to allow its removal from the rod 1 after piercing the skin. In connection with the figures, the sleeve 4 has a diameter substantially equal to the outer diameter of the rod 1, and a longitudinal slot 5 can open sufficiently to allow the passage of the rod 1 through it for the purpose of removing said sleeve.

In addition, the sleeve 4 comprises gripping means to facilitate its removal, including a tongue 6 disposed on its rear end 4b, as shown in the figures. Thus, the practitioner can pull the sleeve 4 to open the slot and slide the sleeve 4 backward (Figure 1a) or downward (Figure 2), according to the length of said sleeve relative to the rod 1, to remove the front end 4a from under the skin by passing the rod 1 through said slot. The method furthermore provides a step of injecting the product into the zone to be treated via the cannula, this step being in particular carried out after the withdrawal of the sleeve 4. In particular, during this step, the product is injected by means of a syringe or other type of container on which the base 3 of the cannula is mounted.

Depending on the product to be injected, the depth of the zone to be treated and / or its location relative to the access hole, the dimensions of the rod 1 may vary. In particular, the rod 1 may have a reduced inner caliber if the product is fluid and on the contrary more important if the product is thick. Thus, with a large internal caliber, the practitioner can inject a thick product without applying too much pressure to said product, which facilitates said injection and reduce pain for the patient. Moreover, by applying less pressure, the molecules of the product are less subject to physical constraints and therefore less likely to be deteriorated.

For example, the rod 1 may have an external gauge between 14G (14 gauges, which corresponds to a diameter of 2 mm) and 33G (0.2 mm), and in particular between 22G (0.7 mm) and 25G ( 0.5 mm).

The rod 1 may also be flexible, to facilitate its sliding to the area to be treated, and then the positioning of its injection port 2 in said area to be treated. In particular, the flexibility of the rod 1 is related to its outer caliber, said flexibility being all the more important that said outer caliber is reduced. In addition, the rod 1 may be at least partially made of stainless steel, in particular alloy SUS 304 or alloy AISI 304 (crude chemical formula FeCrielii0), the latter being particularly remarkable for its good performance in terms of flexibility, robustness , elasticity and resistance to corrosion, and / or a shape memory alloy. In addition, the outer surface of the rod 1 may have undergone a special treatment, for example based on silicone, to facilitate the sliding of said rod under the skin of the patient, and thus to minimize trauma for said patient, including cysts, bruises, bruises or edema. To enable the practitioner to quickly identify the outer caliber and / or the internal caliber of the rod 1, and thus select the cannula bearing said rod according to his needs, the base 3 of said cannula may comprise an identification marking. the outer caliber and / or the inner caliber of said rod.

In particular, the identification marking consists of a coloration of the base 3, the coloration corresponding to the internal size and / or the external gauge of the rod 1. Moreover, the cannula can be packaged in a sterile transparent bag or under a cap, in particular based on polypropylene and / or polyethylene, and stored in a box containing other cannulas also packaged in bags to be protected from moisture and light during storage, the practitioner identifying in one at a glance the cannula which it needs by looking at the coloring of the base 3. In addition, before being packaged in a bag, the cannula is sterilized, for example by means of a method of sterilization by ethylene oxide ( TEE). In addition, the sachet may include indications for the practitioner, such as a lot number, the references of the conformity tests carried out and / or the dimensions of the stem 1, and in particular information useful for the safe use of the cannula it contains, for example, a date of sterilization and / or an expiry date. In particular, if the bag has a poor condition and / or an opening, the practitioner can know immediately that the cannula contained in said bag must be destroyed for the safety of the patient.

In addition, the rod 1 may have a variable length, depending on the depth and / or location of the area to be treated with the cannula relative to the access hole. This length may especially be between 13 mm and 110 mm, and more particularly between 25 mm and 70 mm.

To facilitate the positioning of the injection orifice 2 in the area to be treated, especially when the latter is located at a large depth and / or at a significant distance from the access hole, the rod 1 may have graduated graduations at regular intervals along its length, for example every centimeter.

Furthermore, the base 3 may comprise on its periphery a marking marking of the injection port 2 which is aligned with said injection port, which allows the practitioner to correctly orient said injection port when the one it is positioned in the area to be treated. In particular, the registration marking may comprise a point formed on the periphery of the base 3, said point being made in a sufficiently bright color to contrast with the color of said base.

To limit the pain felt by the patient during the procedure, the method may provide a step prior to piercing the skin, wherein an anesthetic is applied at least on and / or in the area to be pierced, thereby limiting both the pain due to said piercing and the pain due to the introduction of the rod 1. In particular, the anesthetic product can be applied locally in the form of a cream and / or patch, for example an Emla0-type patch. Furthermore, the method can provide for successively treating several areas, and this by accessing from the same access hole. In particular, the practitioner can inject several products in the same area according to the aesthetic effects he wishes to bring to said area. For example, the practitioner can inject several products of the same type which have different viscosities and / or the same product at different depths.

Similarly, the practitioner can inject the same product in several accessible areas from the same access hole. To do this, the method can provide for moving the rod 1 already introduced under the skin by the access hole to another area to be treated after injection of said product in a first zone. Advantageously, the practitioner can remove the sleeve 4 at the beginning of sliding of said rod under said skin to reach the area to be treated. Thus, the injection can be performed only with the rod 1 inserted into the skin, which allows the practitioner to handle the cannula more easily and to perform an injection in a less traumatic way for the patient. In particular, when the product has to be injected in several zones, the sleeve 4 can be removed before moving the rod 1 to another area to be treated, in order to avoid injuring the patient in the zone situated around the access hole. .

In particular, the method can provide a radial displacement of the rod 1 between the newly treated area and a new area to be treated to proceed to a new injection in said new area.

In addition, the method may provide for repeating at least once such radial displacement from the treated area to another area to be treated and a subsequent step of injecting product into said other area. Thus, the practitioner can treat an entire area of the face, for example the forehead, a temple or a cheek, and this from a single access hole.

In particular, to correct a loosening of the skin which is widely spread over an area of the face, for example on the forehead, on a temple or on a cheek, a known technique consists in injecting several small doses of product on the whole of said zone. by making several radial displacements in said zone, in order to stretch said skin over the entire area while giving it volume again. This particular technique is in particular called "topping" and is generally performed in a layer of the hypodermis, in order to achieve smoothing on the surface and plump the skin deep.

In particular, by radially moving the rod 1 already inserted in the hypodermic layer from an already treated zone of said layer to another area to be treated, said rod remains at a constant depth. Thus, the practitioner makes sure to perform all the injections of topping in the same layer, and in particular at the same depth in said layer.

Therefore, the practitioner can easily plump a layer under the skin with a constant thickness of product, which ensures the homogeneity and harmony of the final result.

Furthermore, the method may provide for moving the rod 1 back during the injection of the product, in order to distribute the product over a wide range of depths and / or over a wider area, which allows a more harmonious result and therefore more natural. Alternatively, the method can provide for moving the rod 1 forward, in an antegrade movement, during the injection of the product. Once the injections are complete, the practitioner removes the stem 1 and can massage the treated area, in order to evenly distribute the product and give a more homogeneous and therefore more natural appearance to the correction made. The patient can then see results that are immediately visible and lasting.

Claims (12)

REVENDICATIONS1. Cannula for injecting a biocompatible product under the skin of a patient, said cannula comprising a base (3) intended to be connected to a container of said product, and a rod (1) having a proximal end (1b). ) which is mounted on said base and a distal end (1a) which is equipped with at least one injection port (2), said cannula being characterized in that it further comprises a sleeve (4) which has a a front end (4a) forming a sharp tip (7) to allow piercing of said skin, said sleeve being reversibly associated with said shaft with the tip (7) extending beyond the distal end (1a), said sleeve being manually removable from said rod after piercing said skin. 2. Injection cannula according to claim 1, characterized in that the sleeve (4) is arranged to be manually deformed to allow its removal from the rod (1) after piercing the skin. 3. injection cannula according to claim 2, characterized in that the sleeve (4) has a diameter substantially equal to the outer diameter of the rod (1), and a longitudinal slot (5) can open sufficiently to allow the passage of the rod (1) through it for the removal of said sleeve. 4. Injection cannula according to any one of claims 1 to 3, characterized in that the sleeve (4) comprises gripping means (6) to facilitate removal from the rod (1) after piercing the skin. 5. Injection cannula according to any one of claims 1 to 4, characterized in that the sleeve (4) has a rear portion (8) which is associated on the rod (1). 6. injection cannula according to any one of claims 1 to 5, characterized in that the sleeve (4) has a rear portion (9) which is disposed in longitudinal support on the base (3). 7. Injection cannula according to any one of claims 1 to 6, characterized in that the rod (1) has a length of between 13 mm and 110 mm, in particular between 25 mm and 70 mm. 8. injection cannula according to any one of claims 1 to 8, characterized in that the rod (1) has an external gauge between 14G and 33G, especially between 22G and 25G. 9. Injection cannula according to any one of claims 1 to 9, characterized in that the rod (1) is flexible. 10. A method of injection by means of a cannula according to any one of claims 1 to 9 of a biocompatible product under the skin of a patient in the context of an aesthetic intervention, said method providing the steps of: - Drilling an area of said skin by means of the sharp tip (7) of the front end (4a) of the sleeve (4); - sliding of the rod (1) under said skin from said pierced zone until the distal end (1a) of said rod opens into an area to be treated; injecting the product into said zone to be treated via said cannula; said method being characterized in that it provides removal of the sleeve (4) of said rod after piercing said skin. 11. Injection method according to claim 10, characterized in that it provides to inject a product successively in several areas to be treated, the rod (1) introduced into the skin being moved to another area to be treated after injection of the produced in an area to be treated. 12. Injection method according to claim 10 or 11, characterized in that the product is a filler, in particular based on hyaluronic acid.