RU210690U1 - Catheter for endovascular embolization of visceral arteries - Google Patents

Abstract

The utility model relates to medical equipment, namely to catheters for embolization of visceral arteries through radial (using the radial artery) access. Catheter for endovascular embolization of visceral arteries contains proximal and distal ends, sheath, cannula, inner and outer flexible polymer single-channel reinforced tubular elements. The outer tubular element with a distal end in the form of a truncated cone and a length of 600-750 mm is located in the proximal part of the catheter. The inner tubular element, the effective length of which is 1300-1500 mm, is inserted in the proximal part with a snug fit into the shaft of the outer tubular element, and has a flexible atraumatic tip on the distal part. The proximal end of the inner tubular element is fixed in the cannula, and the outer tubular element is hermetically connected with the proximal end to the cannula. The braid of the inner tubular element is located along the entire length up to the atraumatic tip between the outer and inner walls made of polymeric material. The braid is made by simple spiral winding with a turn width step from the proximal end to the distal end to the atraumatic tip and with reverse winding filling the interturn step. The braid of the outer single-channel tubular element is located along the entire length to the end in the form of a truncated cone between the outer and inner walls made of polymeric material, with a pitch of 0.1 to 0.6 mm. The technical result is the creation of a catheter for endovascular embolization of visceral arteries, which is flexible with significant rigidity and provides control of the movement of the distal end of the catheter. 5 z.p. f-ly, 2 ill.

Description

The utility model relates to medical equipment, namely to catheters for embolization of visceral arteries through radial (using the radial artery) access.

From the field of technology, a catheter is known for conducting selective catheterization and angiographic examination of the visceral branches of the abdominal aorta with access through the radial artery (RU 178025, published on 03/19/2018). This catheter includes an elastic tube, the length of the tube is 110 cm, and the distal end of the catheter is 5 mm long and is located at an angle of 90° to the plane of the proximal part of the catheter, with which it is connected by an arc 21 mm long.

The disadvantage of this device is the lack of amplification of the tube on its proximal part, which prevents bending, creases and twisting of the catheter. In addition, the arc with a diameter of 21 mm does not allow selective entry into the desired arteries due to the large diameter.

Known endovascular device (application US 2004082879 A1, publ. 29.04.2004), having a distal end, a proximal end and a body part between them. The body part is made of a multifilament helically wound row of wire, provided with a sealing coating on the inner or outer surface, or both. The device may be a catheter, a sheath, a sheath, a delivery device, a pusher, an embolization coil delivery device, or a receptacle for an expandable prosthesis used with the delivery device. The helically wound row of wires transmits torque and provides pushing to the device, resisting kinking and providing a small outer diameter to reach very small vessels and pass through very tortuous vessels.

In this catheter, the spiral is wound over a hollow tube, which, in turn, does not have an upper layer of plastic; in accordance, this design solution will act as a constant source of blood clots, and also, when the tortuosity passes, it can have the effect of sawing and pinching the inner surface of the intimal vessel.

Known microcatheter (application WO 2016040736 (A1), publ. 03/17/2016) with a tapering wall having a length and at least three braid sections with different winding pitches, including a relatively low winding pitch at the proximal end and a relatively higher winding pitch at the distal end; said wall has varying flexibility along its length from being relatively more rigid at said proximal end, and being relatively less flexible at its distal end.

When weaving the mesh in one layer along the entire length of the catheter, the above catheter, the device tends to break, since one layer of the braid does not provide the necessary elasticity in the tortuous vascular bed. Also, in the transitions between denser and less dense weaving (rarefaction), weaving density forms zones capable of transferring pushing force not along the entire length of the catheter, but only at the point of transition of these zones, respectively, if there are several such zones along the catheter, then the final transfer of pushing force may not take place, and the catheter will not go in the tortuous vessel along the desired trajectory. This catheter is a microcatheter, which in turn limits its use and passage through it of endovascular instruments, such as balloons with conductors.

The objective of the claimed utility model is to develop an improved intravascular transradial access catheter that is adaptive to the tortuosity of the vascular bed when performing endovascular embolization of visceral arteries.

The technical result is the creation of a catheter for endovascular embolization of visceral arteries, which is flexible with significant rigidity and provides control of the movement of the distal end of the catheter.

The inventive device allows unhindered transradial access (using the radial artery) to perform embolization of visceral arteries, in particular selective catheterization and therapeutic embolization of the uterine arteries in fibroids and malignant neoplasms of the uterus.

The problem is solved by the design of the intravascular catheter.

Catheter for endovascular embolization of visceral arteries, contains a proximal and a distal end, a cannula located at the proximal end, and two flexible polymer single-channel reinforced tubular elements - inner and outer, having different lengths and diameters. Outdoor single channel the tubular element is located in the proximal part of the catheter, has a distal end in the form of a truncated cone and a length of 600-750 mm. The effective length of the inner tubular element (effective length of the catheter) is 1300-1500 mm, the proximal part of the inner tubular element is inserted with a snug fit into the shaft (channel) of the outer tubular element and sealed with UV curable adhesive. At the distal end of the catheter is a flexible J-shaped polymer atraumatic tip. The braid on the inner tubular element is located along the entire length from the proximal end to the distal to the atraumatic J-shaped tip between the outer and inner walls made of polymeric material, while the braid is made by simple spiral winding with a step in the width of the turn from the proximal end to the distal to atraumatic tip and with reverse winding filling the interturn step. The braid of the outer single-channel tubular element is located along the entire length to the end in the form of a truncated cone between the outer and inner walls made of polymeric material, with a pitch of 0.1 to 0.6 mm.

The design of the catheter is illustrated in Fig.1 and Figs. 2.

Figure 1 - catheter.

Fig. 2 - cross section of the proximal part of the catheter.

The effective length 1 (figure 1) of the catheter is 1300-1500 mm, depending on the operation and the anatomical features of the patient, varies in accordance with the anatomical lesions. Proximal A and distal B and parts of the catheter have different diameters: the outer diameter of the proximal part A of the catheter is 6 Fr, and the outer diameter of the distal part B is 5 Fr.

The catheter includes two flexible polymer single-channel tubular elements of different lengths and diameters (figure 1 and 2): a tubular element of greater length - internal 2, the effective length of which is 1300-1500 mm and the outer tubular element 3, which has a length of 600-750 mm and located in the proximal part A of the catheter, while the proximal part of the inner tubular element 2 is inserted into the shaft (channel) of the outer tubular element 3 with a snug fit to the inner wall of the shaft (figure 2). For a strong connection, the tubular elements are fastened with a UV-curable adhesive. The length of the outer tubular element 3 proportionally depends on the effective length of the catheter 1 (the effective length of the inner tubular element 2). The outer diameter of the inner tubular element 2 is 5 Fr, and the outer diameter of the outer tubular element 3 is 6 Fr. The diameter of the inner lumen (channel) 4 of the inner tubular element 2 is the same along the entire length.

The proximal end of the inner tubular element 2 is fixed in the cannula 5 (figure 1) (Luer-port, Luer-port). The outer tubular element 3 is hermetically connected at its proximal end to the cannula 5 (luer port) and fixed with a UV-curable adhesive or cyanoacrylate adhesive and with a heat-shrinkable material.

The distal end 6 of the outer tubular element 3 has the shape of a truncated cone, which improves the transmission of rotational motion.

The distal end of the inner tubular element 2 has a flexible J-shaped polymer atraumatic tip 7. The J-shaped tip 7 reduces injury to the endothelium of the blood vessel and minimizes the risk of thrombosis.

The outer and inner walls of the inner tubular element 2 are made of a plastic polymer material permitted in the manufacture of medical devices, between them along the entire length from the proximal end (from the cannula 3) to the J-shaped atraumatic polymer tip 7, a braid 8 is wound (Fig.2). The inner tubular element 2 is made by extrusion, which makes it possible to fuse the walls of the tube from a polymeric material, such as polyamide. As a result, the surface of the catheter becomes dense and smooth, which helps to reduce friction during the introduction of the distal end of the catheter.

The braid 8 is applied to the inner tubular element 2 by a simple helical winding method. The winding starts from the proximal end A to the distal B to the J-shaped tip 7, and then weaves in the opposite direction from the distal B to the proximal A. The braid 8 is wound from the proximal end with a gap between the turns - with a step in the width of the turn, while in the reverse direction is wound in the same way with a step in the width of the turn, so that each turn lies in the gap formed between the turns of the first winding. Atraumatic J-shaped tip 7 of the catheter does not have a braid.

Wound in the described way, a double braid from the cannula (luer port) 5 to the J-shaped tip 7 of the catheter increases the strength of the catheter, resistance to kinks, while maintaining flexibility. Metal wire is used as a braid. The design of the inner tubular element improves the transmission of rotational motion and provides control of the movement of the distal end of the catheter.

The outer tubular element 3 is made by polymer melt lamination using elastic polymers approved for the manufacture of medical devices, such as polyamide, polyethylene, pebacas or nylon. The outer tubular element 3 contains two layers of polymer - the outer and inner walls, between the inner and outer polymer layers there is a braid 9 (figure 2) with a winding pitch of 0.1 to 0.6 mm, while the tapered end 6 of the outer tubular element 3 does not contain braid. The step of winding the tubular element 3 depends on the given rigidity of the catheter as a whole. Metal wire is used as a braid.

The outer tubular element 3 gives the structure of the catheter the necessary rigidity, while it has sufficient flexibility, improves controllability and transmission of rotational motion, providing control of the movement of the entire catheter and its distal end.

Different methods of manufacturing the inner and outer tubular elements of the catheter allows you to save the minimum size of the outer diameter of the catheter, in particular its proximal part.

Example. Against the background of sedation, a puncture of the right or left radial artery according to Sildenger is performed, 1 ml of an isoket solution diluted in 10 ml of a 0.9% NaCl solution, 1 ml of verapamil is injected through the side channel of the introducer to prevent arterial spasm and from 2500 to 5000 units . heparin for the prevention of thrombotic complications of the radial artery, then an angiographic hydrophilic conductor with a "J" tip with a diameter of 0.018 and 0.035 inches and a length of 1800-2600 mm is inserted under X-ray control into the distal uterine artery.

The next step in the angiographic hydrophilic conductor is the catheter. The presented catheter allows solving several problems associated with the long catheter and the transfer of pushing force to it and the formation of unnecessary loops and bends when passing through possible tortuosity of the vessels of the upper limb at the level of the brachiocephalic trunk leaving the aortic arch, the effect is achieved due to the reinforced proximal part of the catheter and the inner tube of the catheter . After passing through the brachiocephalic trunk into the aortic arch, the catheter is inserted along the conductor into the descending aorta, descending to the level of the bifurcation. The design of the proposed catheter provides controllability and resistance to kinks. Alternately, catheterization of the right and left internal iliac arteries is performed. The guidewire through which the catheter was inserted is removed. After recording the right angiograms, selective catheterization of the right uterine artery is performed. Taking into account the origin of the uterine arteries at different angles individually for each patient, the developed catheter has a tip bend marking (45-90°), which makes it possible to catheterize the target vessel accurately and with less time.

After selective catheterization (diagnosis), planned therapeutic manipulations are performed on the target vessel. The design of the catheter provides the transfer of rotational motion, control of the movement of the distal end of the catheter, translational and rotational movements place the tip of the microcatheter in the pathological vessel and then embolize it (introduce an embolizing substance). The purpose of embolization is to block the branches that supply the fibroids, while maintaining blood flow in the main uterine artery. The presence of a stasis of the contrast agent in the lumen of the artery indicates a satisfactory result of the procedure. Then the catheter is pulled up to the aortic bifurcation and by turning the distal tip in the opposite direction, similar manipulations are performed. After therapeutic embolization of each uterine artery, selective angiography of the target vessels is again performed at the end of the procedure in order to evaluate the result of the intervention. The patient is prescribed intravenous fentanyl and midazolam (dormicum) to reduce pain after embolization. At the final stage, the introducer is removed from the lumen of the artery, hemostasis is achieved by pressing with a pressure bandage for at least 6 hours.

Claims (6)

1. A catheter for endovascular embolization of visceral arteries, containing a proximal and distal end, a braid and a cannula, characterized in that it contains an inner and outer flexible polymer single-channel reinforced tubular elements: an outer tubular element with a distal end in the form of a truncated cone and a length of 600-750 mm located in the proximal part of the catheter, the inner tubular element, the effective length of which is 1300-1500 mm, the proximal part is inserted with a snug fit into the shaft of the outer tubular element, on the distal part it has a flexible atraumatic tip, while the proximal end of the inner tubular element is fixed in the cannula, and the outer tubular element is hermetically connected with the proximal end of the cannula; the braid of the inner tubular element is located along the entire length to the atraumatic tip between the outer and inner walls made of polymeric material, while the braid is made by the method of simple spiral winding with a step in the width of the turn from the proximal end to the distal to the atraumatic tip and with reverse winding filling the interturn step; the braid of the outer single-channel tubular element is located along the entire length to the end in the form of a truncated cone between the outer and inner walls made of polymeric material, with a pitch of 0.1 to 0.6 mm. 2. The catheter according to claim 1, characterized in that the inner tubular element is made by extrusion. 3. The catheter according to claim 1, characterized in that the flexible atraumatic tip of the catheter has a J-shape. 4. The catheter according to claim 1, characterized in that the inner tubular element is bonded with a UV-curable adhesive to the outer tubular element. 5. The catheter according to claim 1, characterized in that the outer tubular element is made by polymer melt lamination. 6. The catheter according to claim 1, characterized in that the outer diameter of the proximal end of the catheter is 6 Fr, the outer diameter of the distal end is 5 Fr.

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