Medical access system

Abstract

The invention relates to a medical access system for providing access to a hollow body of a patient, the access system comprising at least one catheter having a tubular catheter tube, the catheter being designed to, after a sheath of the hollow body to be punctured has been punctured, be slid with at least part of the length of the catheter tube through the sheath of the hollow body via an opening that has been created by means of a puncture needle or in another way, and to dwell in the hollow body for a period of time. Such a hollow body of a patient can for example be a tubular vessel, in particular a blood vessel such as a vein or artery or a lymph vessel, or any other hollow organ.

Description

[0001] Medical access system

[0002] The invention relates to a medical access system for providing access to a hollow body of a patient, wherein the access system has at least one catheter with a tubular catheter tube, wherein the catheter is configured, after performing a puncture of a sheath of the hollow body to be punctured, to be pushed over at least part of the length of the catheter tube through an opening created by means of a puncture needle or in some other way through the sheath of the hollow body and to remain there for a period of time. Such a hollow body of a patient can be, for example, a tubular vessel, in particular a blood vessel such as a vein or artery or a lymphatic vessel, or another hollow organ.

[0003] Medical access systems come in various designs, including indwelling cannulas and venous catheters, for example, for dialysis. Such an indwelling cannula can be designed as an indwelling venous cannula. The medical access system can be designed as a puncture system / catheter system, for example.

[0004] The terms "puncturing" and "puncture" are to be understood in the medical sense. "Puncture" refers to the insertion of a puncture needle into the hollow body in such a way that the puncture needle penetrates the shell of the hollow body to be punctured.

[0005] The near-hollow section of parts of the indwelling cannula is considered to be those parts that, from the user's perspective, are located at the far (distal) end of the indwelling cannula and thus close to the punctured hollow body. Accordingly, far-hollow sections are located at the proximal end of the indwelling cannula from the user's perspective, i.e., further away from the punctured hollow body. In the context of medical applications of the indwelling cannula, the terms "near-vein" or "near-patient" or "far-user" are used synonymously with the term "near-hollow body." For the term "far-hollow body," the terms "far-vein" and "far-patient" and "far-user" are also used.

[0006] Components close to the vein tend to be located inside the patient, while those far from the vein tend to be located outside. This doesn't always apply, but it is intended to further clarify the terms. The additions are usually self-explanatory, and context is crucial.

[0007] A puncture-resistant venous catheter is known from PCT / EP2019 / 057097.

[0008] The goal is to create an improved medical access system in the form of a general puncture / catheter system. In principle, the improved medical access system makes it possible to effectively puncture and insert a catheter into all body cavities and interbody spaces, as well as all anatomical and pathological structures that require puncture. It is also possible to perform a puncture without inserting a catheter.

[0009] In principle, components of the improved medical access system can also be combined with all known puncture and catheter systems or used as standalone products.

[0010] The term "indwelling cannula" will be retained in part below, but has a broader meaning in the sense of a general medical access system or puncture system that can be used for more than just veins. The terms "vein" and "veins" therefore essentially encompass all blood vessels and, more generally, all body cavities and interbody spaces, as well as all anatomical and pathological structures that are to be punctured and catheterized.

[0011] For example, the indwelling cannula can also be used to puncture the trachea, pleural space, abdominal cavity, stomach, intestines, renal pelvis, urinary bladder, structures of the central and peripheral nervous system, cerebrospinal fluid space, and bones. Pathological structures such as abscesses in and on the patient can also be punctured. Arterial blood vessels can also be punctured advantageously. The term "patient" in the following includes all living beings of all ages and genders. Applications in technical fields and in and on all objects and structures, e.g., in and on reservoirs, containers, cavities, expandable materials, and in and on pump, hose, tube, and port systems, are also explicitly possible.

[0012] When the word “or” is used below, possible alternatives are shown, but combinations of the characteristics or characteristics separated by “or” are also explicitly possible.

[0013] All described components can be used singly or multiple times on an indwelling cannula, independently of such a cannula, on / in other products, or completely independently. Various features of different components can also be freely combined, and features of certain components can also be used on other components without this being explicitly stated. In principle, all components and features can be used both inside and outside a patient.

[0014] Indwelling catheters, and in particular venous catheters, are specialized medical devices in that they must have specific diameters and lengths to be applied to the usual venous access sites in human or animal patients. This also requires a certain degree of flexibility or elasticity of the catheter tube. Such catheters are therefore not comparable to catheter systems for other applications, such as urinary catheters, because completely different requirements apply.

[0015] The invention is based on the object of providing a medical access system that is easier and safer to use.

[0016] This object is achieved by a medical access system according to claim 1. Advantageous further developments are specified in the subclaims.

[0017] According to the invention, at least the part of the catheter tube designed to remain in the hollow body has at least one spiral support structure over its entire length or the majority of its length, in particular in the form of at least one spirally wound, internally hollow guide wire. Due to the spiral shape of the support structure, an inner cavity is formed therein through which the puncture needle can be guided. The spiral support structure arranged in the catheter tube can support the catheter tube and, in particular, can prevent sharp kinking of the catheter tube. The spiral support structure keeps the inner lumen of the catheter tube permanently open, thus preventing blockages. The spiral support structure increases the bending section modulus and / or the radial section modulus of the catheter tube.

[0018] Due to the spiral support structure, the catheter tube can adapt to the course and branches of blood vessels or other anatomical structures, for example, without sharp bends. In addition to its use with / on indwelling cannulas, this can also be particularly advantageous when the catheter tube according to the invention is longer, e.g., up to 200 cm, and must be advanced over a longer distance into the body, e.g., in applications in the field of interventional cardiology or (neuro)radiology, or in minimally invasive surgical procedures.

[0019] Any conventional / commercially available, single- or multi-lumen catheter tube or other tube with any diameter and length can be used.

[0020] The support structure can, for example, be a spiral structure extending over a certain longitudinal section of the catheter tube. Several such coaxial support structures can also be present. The spiral support structure can also have spring-like properties. The spiral structure can be formed from round or flat material, in particular from a metal material. The catheter tube can be formed in a single or multi-layered manner in the radial direction, using either the same or different materials in the individual radial layers.

[0021] The support structure can be wave-shaped or have a wave-shaped surface. A wave-shaped surface is characterized, at least in cross-section along the longitudinal axis of the support structure, by alternating diameters of the support structure. A wave shape can consist of a sine, rectangular, triangular and / or sawtooth oscillation, for example. The support structure can also consist of at least one braid-like structure or be further developed with at least one such structure. The support structure can also consist of at least one structure running longitudinally, transversely or diagonally to the longitudinal axis of the catheter tube or can be further developed with at least one such structure. At least one such structure can also encompass or bridge a certain section of the support structure and thus counteract, for example, a change in length or, in the case of a spiral-shaped support structure, a de-spiralization.Other designs and shapes of the support structure and its surface are also conceivable. For example, the support structure can have either a smooth or a dimpled surface. The surface of the support structure can consist of at least one material or be coated with at least one material characterized by increased or high lubricity.

[0022] Materials such as polyurethane (PU) or FEP can be used for the catheter tube. Materials for the support structure can be metal, particularly stainless steel, and / or metal alloys, particularly nitinol. Nitinol has the advantage of further increasing the desired resistance of the catheter tube to compression or kinking due to its memory effect.

[0023] Other materials for the support structure can be plastic materials, in particular fiber-reinforced plastics, e.g. carbon or aramid fiber-reinforced plastics. The materials for the support structure can be polymers. The materials for the support structure can be polycondensates. The materials for the support structure can be polyadducts. The materials for the support structure can be thermosets or thermoplastics. Plastic materials characterized by high mechanical strength can also be used, e.g. polyimides. Plastic materials with rubber-elastic properties can also be used, e.g. silicone elastomers. Resins can also be used, e.g. unsaturated polyester resins. Polyethylene can also be used. Polytetrafluoroethylene (PTFE) can also be used. Polyvinyl chloride (PVC) can also be used. For example, the support structure can be designed as a rigid PVC spiral.Materials that exhibit sufficient or good magnetic resonance imaging (MRI) suitability can be advantageously used for the support structure. Materials that exhibit sufficient or good insulation against heat and / or electrical current can be advantageously used for the support structure. Such materials can also be embedded in the spiral support structure with interruptions by other materials. Only certain areas of the spiral support structure can also be designed as areas with sufficient or good insulation. It is also conceivable that special adhesives could be used for this purpose.

[0024] The catheter tube may be made of one or more of the materials mentioned. The support structure may be made of one or more of the materials mentioned.

[0025] Composite materials and materials that expand or strengthen when heated by body temperature can also be advantageously used. The spiral support structure can be made entirely or partially of bimetal.

[0026] The support structure can also be partially, predominantly, or completely made of or coated with at least one resorbable material that is readily soluble in blood and infusion solutions. This resorbable material can be a carbohydrate, but also another biomolecule or a salt. This material can also be or contain magnesium. Resorbable polymers, composites, bioceramic materials, or biodegradable metals can also be used. The material can also be a combination of several resorbable materials and can also contain at least one antimicrobial, anticoagulant, or other effective or biologically active substance, or be coated with at least one such substance.

[0027] The support structure can also serve as a sensor and / or detector or be part of such a sensor and / or detector in order to detect certain properties or changes in the state of the catheter tube, e.g. compression or bending of the catheter tube. Such a sensor and / or detector can advantageously also detect properties or changes in the state of the catheter tube, e.g. with regard to the following parameters / measured values ​​of the blood: temperature, oxygen content, electrolytes, pH value, blood sugar, kidney and liver function. In the case of a pulse-synchronous and / or blood pressure-associated change in the shape / state of the support structure, e.g. expansion in the radial or longitudinal direction, the measurement of parameters that serve to determine the arterial blood pressure and associated values ​​in order to be able to assess the patient's circulatory function is also conceivable when the catheter tube according to the invention is in an arterial position.When the catheter tube according to the invention is positioned in a venous vein, it is conceivable to determine venous pressure. It is also conceivable that the support structure could be used to measure the width of blood vessels, particularly changes in the tone (tension) of blood vessels.

[0028] In a spiral design of the support structure, there may be one spiral or several nested spirals. At least one of such spirals can also be designed as a sensor and / or detector. If there are multiple spirals, these can be made of different materials. Advantageously, at least one spiral can be electrically conductive and at least one further spiral can be electrically insulating. The turns of the spiral can have the same distance from one another over the entire length of the support structure or can have varying distances. In an advantageous embodiment of the invention, a spiral support structure can have a smaller distance between the turns in the area distant from the hollow body than in the area close to the hollow body.

[0029] By using such a support structure, the visibility of the catheter in patients can be improved by means of medical imaging procedures, e.g. by ultrasound examination, when using a material that is visible in medical imaging procedures, in particular a metal material.

[0030] According to an advantageous embodiment of the invention, the spiral support structure is arranged loosely in the catheter tube over most or all of its longitudinal extent. In this way, the supporting effect of the spiral support structure can be further optimized. If the catheter tube is bent, the spiral support structure can loosely follow this change in shape without excessive stress occurring in the material of the spiral support structure. This can, in particular, improve the resistance to kinking compared to implementations in which the spiral support structure is embedded in the material of the catheter tube or in another material and the individual spiral turns cannot move freely relative to the catheter tube.

[0031] For example, the spiral support structure can rest loosely against the inside of the catheter tube. The spiral support structure can move slightly relative to the catheter tube when the catheter tube is bent. Therefore, even if the spiral support structure is attached to the catheter tube or another part of the indwelling cannula, it can be moved at least slightly relative to the catheter tube in the unattached areas. The spiral support structure can have a certain amount of play in the radial direction relative to the inside of the catheter tube.

[0032] It is also conceivable that the catheter tube also contains sections along whose length a spiral support structure is present, which is not loosely arranged but firmly arranged within the catheter tube. It is also conceivable that the extent of the relative movement of the spiral support structure relative to the catheter tube varies in different sections of the catheter tube.

[0033] The spiral support structure can, for example, be designed like a piece of Seldinger wire. Unlike a Seldinger wire, however, the spiral support structure is fixed to the catheter tube, preventing it from falling out or escaping from the catheter tube due to improper use. Once the catheter tube is attached to the patient, the spiral support structure remains in the catheter tube throughout the entire insertion period.

[0034] According to an advantageous embodiment of the invention, the spiral support structure is permanently attached to the catheter tube or a component of the medical access system connected thereto via at least one fastening element. Such a fastening element ensures that the spiral support structure does not fall out of the catheter tube or change its position undesirably. However, the individual turns of the spiral support structure remain predominantly loosely arranged in the catheter tube. In contrast to known applications using a Seldinger wire, the spiral support structure thus differs in its permanent arrangement within the catheter tube, without protruding from it and without being able to be removed.

[0035] According to an advantageous embodiment of the invention, the spiral support structure is secured at one or both ends to the catheter tube or a component of the medical access system connected thereto via at least one fastening element, and is otherwise loosely arranged in the catheter tube. Accordingly, the spiral support structure is only secured at one end, so that the regions of the spiral support structure located between the ends, or in the case of only one-sided attachment, also an end side facing away from them, are / is loosely arranged in the catheter tube.

[0036] The spiral support structure can, for example, be fixed at only one end such that the spiral support structure is not movable at this fixed end in either one axial direction or the opposite axial direction. If the spiral support structure is fixed at both ends, the spiral support structure can, for example, be inserted between two fastening elements that fix it in opposite axial directions. The spiral support structure can then have a certain amount of axial play between the two fastening elements, i.e., be slightly displaceable in the axial direction.

[0037] According to an advantageous embodiment of the invention, a tubular inner body is arranged within the spiral support structure. In this way, the spiral support structure is shielded inwards by the tubular inner body, e.g. against a puncture needle passed through it or against liquids passed through it. The spiral support structure can be arranged on the tubular inner body with a certain radial play. The tubular inner body extends longitudinally through the spiral structure. The tubular inner body can extend over the entire length of the spiral support structure or only over part of this length. The tubular inner body can also be longer than the spiral support structure and protrude from it at one or both ends.

[0038] For example, the catheter tube can have a tubular outer body and a tubular inner body, which is arranged at a radial distance within the tubular outer body, wherein an annular gap is formed between the tubular outer body and the tubular inner body, in which the spiral support structure is arranged. The spiral support structure can be arranged with a certain radial play in the annular gap. A substance can also be located in the annular gap, e.g. an oil- or grease-containing substance or other substance or liquid, which reduces the frictional resistance between the spiral support structure and its surroundings. The inventive displaceability of the spiral support structure relative to its surroundings is thus further improved. Such a substance or liquid can, for example, also have other properties, e.g.maintain the spiral support structure and its surroundings within a specific temperature range or protect the material used from change, wear or destruction, e.g. breakage or corrosion, or from contamination by germs.

[0039] The tubular inner body can also be arranged in and / or on a component of the medical access system other than the catheter tube, for example, the support assembly explained below. The tubular inner body can be designed, for example, like a tube or hose.

[0040] In an alternative embodiment, the spiral support structure is not covered by an inner layer on the inside, meaning it is exposed and can, for example, come into contact with fluids passed through the catheter tube. If a puncture needle is passed through the catheter tube, it can, for example, rest directly against the inside of the spiral support structure.

[0041] According to an advantageous embodiment of the invention, the spiral support structure is detachably attached to the catheter tube or a component of the medical access system connected thereto, and can be removed from the catheter tube if necessary. This has the advantage that the spiral support structure can be removed or replaced, even when the catheter is already in place on the patient. This can be useful, for example, if the catheter tube becomes blocked. It is also possible, after removing a spiral support structure from the catheter tube, to insert another spiral support structure there that has the same or a different length, e.g. a spiral support structure that is overall longer than the spiral support structure originally arranged there. There can also be several removable or replaceable spiral support structures.

[0042] According to an advantageous embodiment of the invention, the medical access system has a support assembly as a further component, which is present in addition to the catheter and is detachably coupled to the catheter, for example to a housing of the catheter, wherein the support assembly has the spiral support structure. This has the advantage that the spiral support structure can be easily removed from the catheter tube by the user by removing the entire support assembly. For example, the user can grip a housing of the support assembly to remove the support assembly. In the manufactured and delivered state of the medical access system, this system can then be delivered with all components, i.e. at least with the catheter and the support assembly attached to it. Depending on the design of the medical access system, the needle device can also be arranged thereon.

[0043] According to an advantageous embodiment of the invention, the spiral support structure is permanently fixed to a part of the support assembly, for example, to a housing of the support assembly. For example, the spiral support structure can be molded into the material of a part of the support assembly or permanently attached thereto by form-fitting or by other means, e.g., by adhesive, welding, and / or pinning.

[0044] In an advantageous embodiment of the invention, the housing of the support assembly can have fastening elements that are assigned to corresponding fastening elements of the catheter housing, designed as counterparts. The support assembly can then be attached to the catheter via these fastening elements by coupling the housing of the support assembly to the catheter housing. For example, the fastening elements can be designed as a bayonet connection and / or as locking elements. Multiple support assemblies can also be present.

[0045] When replacing the spiral support structure, a different spiral support structure can be inserted after removing one spiral support structure, e.g. a spiral support structure that has the aforementioned tubular inner body. In this case, the tubular inner body can protrude so far beyond the spiral support structure at the end closest to the patient that when the spiral support structure is fully inserted into the catheter tube, the tubular inner body protrudes from the end of the catheter tube near the patient and is thus inserted, for example, into a vein or another hollow body of the patient. With such a tubular section protruding from the catheter tube at the end closest to the patient, a venous valve can be bridged, for example.

[0046] Alternatively, such a tubular section protruding from the catheter tube at the patient-proximal end can also be provided by an additional component attached to the patient-proximal end of the spiral support structure, e.g., by welding, plugging, and / or gluing. In this case, the spiral support structure can also be designed without the tubular inner body. The aforementioned tubular section, designed as an additional component, is then attached to the patient-proximal end of the spiral support structure.

[0047] According to an advantageous embodiment of the invention, the spiral support structure has a plurality of spiral turns that lie directly next to one another. This results in a good supporting effect of the spiral support structure. The spiral support structure can have such spiral turns that lie directly next to one another only in one or more individual regions; it can also be designed in this way over its entire length. In these regions, the spiral support structure is thus tightly wound, for example similar to a Seldinger wire. There is no space between the individual turns. The region of the spiral turns that lie directly next to one another can extend over the majority of the longitudinal extent of the spiral support structure or over the entire longitudinal extent.The spiral support structure may also have one or more regions in which the spiral turns are spaced from each other, wherein in these regions the spiral turns may have a constant or a variable pitch over the length.

[0048] According to an advantageous embodiment of the invention, the spiral support structure comprises a plurality of spiral turns that are loosely adjacent to one another but not secured to one another, e.g., not glued or similarly, and in particular not embedded in a connecting material. In this way, the spiral turns can shift relative to one another when the catheter tube is bent. This optimally dissipates stresses in the spiral support structure, further improving the support effect.

[0049] According to an advantageous embodiment of the invention, the spiral support structure or its spiral windings are provided with a friction-reducing coating, in particular a PTFE coating. This facilitates, for example, the withdrawal of a puncture needle from the spiral support structure. Alternatively or additionally, the inside of the catheter tube can also be provided with such a friction-reducing coating, in particular a PTFE coating.

[0050] According to an advantageous embodiment of the invention, the spiral support structure extends only over part of the longitudinal extent of the catheter tube. The spiral support structure is thus shorter than the catheter tube and cannot protrude from the catheter tube in any operating state of the access system, especially not from the end closest to the patient. The specified length refers to the length of the spiral support structure in the wound state, not in the stretched state of the material of the spiral support structure.

[0051] The diameter of the spiral support structure can remain constant over its entire length. Advantageously, the inner diameter of the spiral support structure can be selected such that a puncture needle can be guided through the spiral support structure with little play. According to an advantageous embodiment of the invention, the catheter tube ends at the end closest to the patient with an axial opening whose inner diameter is smaller than the outer diameter of the spiral support structure or at least of the end region of the spiral support structure closest to the patient. The axial opening serves, for example, as an outlet opening of the catheter tube for administering medication to the patient. If a puncture needle is guided through the catheter tube, the axial opening serves to guide the puncture tip of the puncture needle out of the end of the catheter tube closest to the patient, for example to perform a puncture.

[0052] According to an advantageous embodiment of the invention, the medical access system is designed as an indwelling cannula for puncturing a hollow body of a patient using a puncture needle, wherein the indwelling cannula has at least the catheter with the tubular catheter tube, in which the puncture needle can be guided in a longitudinally displaceable manner, wherein the catheter is configured, after performing a puncture of a sheath of the hollow body to be punctured, to be pushed over at least part of the length of the catheter tube through the opening created by the puncture needle through the sheath of the hollow body to be punctured and to remain there for a period of time. In this way, it is ensured that the spiral-shaped support structure cannot protrude from the end of the catheter tube closest to the patient under any circumstances, even in the event of incorrect operation of the access system.

[0053] Such an indwelling cannula can be designed, for example, as a venous indwelling cannula, also known as a peripheral venous catheter.

[0054] Such an indwelling cannula can also be designed as an arterial catheter.

[0055] Such an indwelling cannula can also be designed as a catheter for puncturing the pleural space.

[0056] The catheter tube according to the invention with the spiral support structure can also be used on / with medical access systems that serve to puncture central veins. The catheter tube with the spiral support structure can therefore be part of central venous catheter systems. In an advantageous embodiment of a central venous catheter system, several or all of the tubes (lumens, branches) leading into the vein and branching off from the main tube are designed as the above-mentioned catheter tube according to the invention with the spiral support structure. However, it is also conceivable that only selected lumens are designed according to the invention, e.g. those that must be particularly secured against kinking. In this case, selected lumens can also be designed as a catheter tube with the spiral support structure according to the invention only in sections over at least part of its length or the predominant length.It is also possible to design only the area of ​​the lumina like the catheter tube according to the invention, where the lumina enters the patient's skin and / or the vein, since in this area the risk of the catheter tube kinking is particularly high.

[0057] The catheter tube according to the invention with the spiral support structure can also be used on / with pulmonary artery catheters.

[0058] The catheter tube according to the invention with the spiral support structure can also be used on / with medical puncture catheter systems (access systems) in the field of interventional cardiology and interventional radiology and neuroradiology.

[0059] The catheter tube according to the invention with the spiral support structure can also be used independently, without being part of a medical puncture / catheter system. For example, it can be used on / with an infusion / transfusion tube or can itself represent one. Such a tube can also be designed so that it is suitable for high flow rates, which allow, for example, dialysis to be carried out. The catheter tube according to the invention can have a length of up to 10 meters, preferably a length of 1 to 2 meters. The spiral support structure is then also extended accordingly. It is also conceivable for the spiral support structure to only encompass those areas of the catheter tube which must be particularly protected against kinking, i.e. for the spiral support structure not to be arranged in the entire catheter tube.In such a case, the spiral support structure can also be connected to the catheter tube at multiple locations, or the catheter tube can contain multiple, separate spiral support structures. If external mechanical deformation of the catheter tube is desired, e.g., when using a peristaltic pump or peristaltic pump, there can be no spiral support structure at the corresponding location, or there can be a spiral support structure with special properties. It is also conceivable that the catheter tube also contains sections along whose length a spiral support structure is present, but which is not loosely arranged but firmly arranged in the catheter tube.

[0060] The catheter tube according to the invention with the spiral support structure can also be a component of an infusion-Ztransfusion system.

[0061] The catheter tube according to the invention with the spiral support structure can also be a component of a puncture catheter system for performing regional anesthesiology and interventional pain therapy procedures. This includes peripheral procedures as well as procedures near the spinal cord and joints.

[0062] The catheter tube according to the invention with the spiral-shaped support structure can also be a component of a puncture catheter system for draining cerebrospinal fluid (CSF).

[0063] The catheter tube according to the invention with the spiral support structure can also be part of a puncture catheter system for draining urinary tract fluid.

[0064] The catheter tube according to the invention with the spiral-shaped support structure can also be part of a drainage system which drains fluids from the body, e.g. wound secretions.

[0065] The catheter tube according to the invention with the spiral support structure can also be used independently to be inserted into blood vessels and to keep them open over a longer period of time andZ or also, for example, to cover Z or bridge defects in the blood vessel wall. Thus, the catheter tube according to the invention with the spiral support structure can be used as a stent, e.g. in the coronary arteries. It can also be used as a stent or vascular prosthesis in larger blood vessels, e.g. in arm and leg vessels and in the main artery (aorta) or the vena cava inferiorZsuperior. For this purpose, significant deviations in the diameter and length dimensions from those of, for example, indwelling cannulas are conceivable, e.g. up to 4 cm in diameter and up to 120 cm in length. The catheter tube according to the invention with the spiral support structure can also be used as a dialysis shunt or as an element thereof.

[0066] The catheter tube according to the invention, with its spiral support structure, can also be used as a hose, even if it is not necessarily intended for medical use. With the diameter and length dimensions commonly used in medical applications, it can also be used as a hose in the medical field, e.g., as a shower hose. Application as a garden hose is also conceivable, as is application as a fuel hose or fire hose.

[0067] In principle, the catheter tube according to the invention with the spiral support structure can be used as a tube in all applications where sharp kinking of tubes should / must be prevented. The catheter tube according to the invention with the spiral support structure can thus also be used as a standalone tube, which can be used in a wide variety of applications.

[0068] The catheter tube according to the invention with the spiral support structure can also be at least one component of a variety of devices, machines, pump systems, installations and, for example, also of engines and means of transport.

[0069] In principle, significant deviations in diameter and length dimensions, as well as wall thickness, compared to indwelling cannulas are conceivable and sometimes necessary for all of the above-mentioned further embodiments of the catheter tube according to the invention. These deviations can also extend to the nanoscale (nanostructures).

[0070] The catheter tube according to the invention with the spiral support structure can be bent and / or angled at least one bending or angling point, particularly in the region of the transition to other components of a medical access system, e.g., a venous cannula, away from the vein. The bending or angling point of the catheter tube according to the invention with the spiral support structure is located, for example, in the area of ​​skin level when the venous cannula is in place in the patient. There, a catheter tube can be exposed to particular mechanical stresses due to use. In contrast to a catheter tube that runs straight out of the venous cannula towards the vein, the catheter tube according to the invention with the spiral support structure can be bent and / or angled at least 1° relative to a straight line at the bending or angling point, but preferably at an angle of 2 to 5°, 6 to 10°, 11 to 25°, 26 to 45°, or more than 45°.The catheter tube according to the invention with the spiral support structure thus forms a bend that can be directed upwards or downwards. A puncture needle inserted through the catheter tube according to the invention with the spiral support structure can also be curved and / or angled as described above. This can facilitate puncture procedures, as it allows for flatter punctures or punctures in the area of ​​bony protrusions or joints, for example, or even more individually tailored to the anatomical conditions.

[0071] The catheter tube according to the invention with the spiral support structure can be further developed with at least one further net-, braid-, or grid-like structure in the area of ​​the skin or in other areas subject to high mechanical stress. A combination with transverse, longitudinal, or diagonal structures is conceivable; these can also provide the desired / increased stability of the wall of the catheter tube, at least in sections, without the need for a spiral support structure at least in sections. The catheter tube can also be further developed in other critical areas, e.g., in the area of ​​the entry point into the vein or in the area of ​​its distal end, in the manner just described or in a different manner.

[0072] If a puncture needle inserted through the catheter tube according to the invention with the spiral support structure has a tip with an oblique bevel, various puncture techniques are possible. In the bevel-up technique, the puncture needle tip is inserted through the skin in such a way that the oblique bevel, including the inner opening of the puncture needle, points upwards, i.e., away from the patient's skin. In the bevel-down technique, the puncture needle tip is rotated by 180° relative to the catheter tube, so that the oblique bevel, including the inner opening of the puncture needle, points downwards, i.e., towards the patient's skin. The medical access system according to the invention, e.g., the venous cannula, can, for example,be designed such that the puncture needle, or at least the puncture needle tip, can be rotated around its longitudinal axis at any time relative to the catheter tube according to the invention with the spiral support structure. The user can then optionally apply the bevel-up technique or the bevel-down technique. The catheter tube according to the invention with the spiral support structure can facilitate this rotation around its longitudinal axis, since the inventive design of the catheter tube with the spiral support structure prevents sharp bending, which could complicate the rotation of the puncture needle around its longitudinal direction.

[0073] The medical access system according to the invention, e.g. the venous cannula, can also be designed such that the puncture needle or at least the puncture needle tip cannot be rotated relative to the catheter tube according to the invention with the spiral support structure in at least one specific longitudinal displacement position, e.g. when the puncture needle tip protrudes from the catheter tube according to the invention with the spiral support structure at the end closest to the patient, or can only be rotated with increased force. For example, an assembly comprising the puncture needle can be positively coupled in this longitudinal displacement position to an assembly comprising the catheter tube according to the invention with the spiral support structure, thus preventing the puncture needle from rotating relative to the catheter tube according to the invention with the spiral support structure.

[0074] In this case, the medical access system according to the invention, eg the venous cannula, can be designed such that the oblique bevel including the inner opening of the puncture needle therein points downwards from the outset, ie faces the skin of the patient or an underside of the indwelling cannula on which at least one fixation wing of the indwelling cannula is arranged.

[0075] According to a further advantageous embodiment of the medical access system according to the invention, e.g. the venous cannula, it is provided that the puncture needle tip is turned / rotated about its own longitudinal axis and / or the longitudinal axis of the puncture needle and is preferably adjustable to a circular dimension of 45°, 90°, 135°, 180°, 225°, 270°, 315° or 360° (angles given in degrees relative to a circular dimension of 360 degrees (360°)), whereby all intermediate stages with regard to the circular dimension are conceivable. In this case, due to the design, the oblique bevel of the puncture needle tip no longer necessarily points upwards before use of the medical access system according to the invention, e.g. the venous cannula, and is therefore no longer necessarily facing away from the patient's skin.

[0076] This can advantageously enable gentler puncture techniques, since, among other things, puncture / puncture angles can be varied. The puncture needle or an assembly comprising the puncture needle can have holding / travel-limiting elements (hereinafter referred to as "holding elements"), by which the rotation / rotation of the puncture needle tip / puncture needle is limited or eliminated, at least in certain longitudinal displacement positions of the puncture needle tip and / or puncture needle and / or needle device, relative to the catheter tube according to the invention with the spiral support structure.

[0077] In an advantageous embodiment of the medical access system according to the invention, e.g. the venous cannula, the just described rotatability of the puncture needle tip / puncture needle is completely eliminated when the puncture needle tip projects at least partially distally (towards the patient) beyond the catheter tube according to the invention with the spiral support structure. The holding elements can be designed, for example, as locking elements, notches, grooves or projections. These can interact with holding elements located on the catheter tube according to the invention with the spiral support structure or on other components of the medical access system according to the invention, e.g. the venous cannula, for example by locking, wedging or twisting. All holding elements can be at least partially made of a material or coated with at least one such material that increases frictional resistance.The angle specifications mentioned above can be indicated for the user on a component of the medical access system, e.g. the venous cannula, so that the current circular dimension to which the puncture needle tip and / or puncture needle is set can be easily read. Circular or semi-circular markings in different line thicknesses and, for example, colored markings in the traffic light colors "green", "yellow" and red are also conceivable. It is also conceivable that the initial puncture and further advancement of the puncture needle tip and / or puncture needle into the tissue to be punctured takes place in such a way that the puncture needle tip and / or puncture needle is sequentially set to a different circular dimension, i.e., is turned / rotated around the longitudinal axis of the puncture tip / puncture needle in the chronological sequence of the puncture procedure.

[0078] In a further advantageous embodiment, the invention relates to a medical access system for providing access to a hollow body of a patient, wherein the access system has at least one catheter with a tubular catheter tube, wherein the catheter is configured, after performing a puncture of a sheath of the hollow body to be punctured, to be pushed over at least part of the length of the catheter tube through an opening created by means of a puncture needle or in some other way through the sheath of the hollow body and to remain there for a period of time, wherein at least the part of the catheter tube configured to remain in the hollow body has at least one support structure over its entire length or the majority of its length. This support structure does not have to be spiral-shaped, but can, for example, be cylindrical, tubular, or hose-shaped.Such a support structure can advantageously be further developed with the features explained above and below for the spiral support structure. For example, parts of the catheter tube can be supported by such a support structure. Several support structures constructed in this way can also be provided, which are arranged so as to be displaceable relative to the puncture needle, the catheter tube, and / or relative to one another, in particular also longitudinally displaceable, for example, in the sense of a telescopic arrangement.

[0079] The invention is explained in more detail below using exemplary embodiments and drawings.

[0080] It shows

[0081] Figure 1 shows a medical access system in the form of an indwelling cannula in perspective view,

[0082] Figure 2 shows the patient-near area of ​​a catheter tube in side view, Fig. 3 - 5 shows the patient-near area of ​​a catheter tube in lateral sectional view in various embodiments,

[0083] Figure 6 is a cross-sectional view of the catheter tube according to Figure 5,

[0084] Figure 7 shows a further embodiment of a medical access system in perspective view,

[0085] Figure 8 shows the system according to Figure 7 in an exploded view,

[0086] Figure 9 Parts of the system according to Figure 7,

[0087] Figure 10 a support assembly,

[0088] Figure 11 shows the support assembly according to Figure 10 with a catheter.

[0089] The medical access system shown in Figure 1 comprises a catheter 29 and a needle device 39. The needle device 39 forms a separate structural unit from the catheter 29, which can be separated from the catheter 29 after a puncture has been performed. Only the catheter 29 then remains on the patient.

[0090] The catheter 29 has a housing 20, on which a tube exit area 21 is provided on a side facing the patient, from which a catheter tube 1 protrudes from the housing 20. The catheter tube 1 is relatively flexible and serves as an application option for the intravenous introduction of fluids, in particular infusion solutions, blood products, and medications. The catheter tube 1 is then located with its distal part in a hollow body, e.g., in a patient's vein.

[0091] The needle device 39 comprises a puncture needle 30, which, in the initial state of the medical access system, is located largely within the housing 20 and the catheter tube 1, with the tip 31 of the puncture needle 30 protruding from the distal end of the catheter tube 1. The needle device 39 is displaceable in the longitudinal direction L relative to the catheter 29.

[0092] Fixing wings 23 are arranged on the housing 20 for manual handling and for securing the catheter 29 to the patient. On the side facing away from the tube exit area 21, the housing 20 has a needle opening 25 through which the puncture needle 30 can be placed in the housing 20 and the catheter tube 1. After the medical access system has been applied to the patient, the needle device 39 is removed. The needle opening 25 then serves as a connection option for, for example, an infusion line or an aspiration element, such as a syringe.

[0093] The housing 20 may also have an injection port, which protrudes from the housing 20, for example, on the side facing away from the fixing wings 23. The injection port is used for injecting medication. It is otherwise closed by a cap.

[0094] The needle device 39 also has a closure element 34 with a plug and a handling element 32 at the proximal end of the puncture needle 30. In the initial state, the needle opening 25 is closed by the closure element 34. The handling element 32 serves to manipulate the needle device 39 by the user, i.e., essentially to retract the puncture needle 30 after the puncture has been completed. As mentioned, the needle device 39 is removed after the catheter 29 has been applied to the patient.

[0095] The needle device 39 can have a connection port at its proximal end, i.e., in the region of the handling element 32, for connecting a syringe or an infusion line, e.g., for blood aspiration. The connection port is closed by a closure cap 40. The closure cap 40 can, for example, be screwed or plugged on.

[0096] Figure 2 shows that the catheter tube 1 is tubular on the outside, e.g., with a cylindrical outer shape. At the end closest to the patient, the catheter tube 1 terminates with a dilation section 6, which tapers towards the free end on the outside. At the free end, the catheter tube 1 has an axial opening 7, which serves as the outlet of the catheter tube 1 for administering medication. In the case of an indwelling cannula, the puncture needle 30 also extends from this opening 7.

[0097] Figure 3 shows a cross-sectional view of a first embodiment of the medical access system with a catheter tube 1 in which a spiral support structure 2 is arranged. In this case, the catheter tube 1, in addition to a tubular outer body 15, also has a tubular inner body 3 which is arranged inside the tubular outer body 15. Between the tubular outer body 15 and the tubular inner body 3, an annular gap is formed, in which the spiral support structure 2 is arranged with a certain radial play. In a further advantageous embodiment, the spiral support structure 2 can be connected to the tubular inner body 3. In this case, the support structure 2 and the tubular inner body 3 form a connected unit which is axially displaceable relative to the tubular outer body 15.

[0098] It can also be seen that the tubular outer body 15 also tapers towards the end in terms of cross-sectional dimensions on the inside in the dilation section 6. In this area, the spiral support structure 2 is no longer arranged; a free space 4 may be present there.

[0099] Figure 4 shows a further advantageous embodiment of a catheter tube 1 without the tubular inner body 3. It can be seen that the spiral support structure 2 is arranged directly within the catheter tube 1 and is not covered on the inside. The puncture needle 30 is then guided directly within the spiral support structure 2.

[0100] As a further advantageous embodiment, Figure 5 shows a catheter tube 1 designed similarly to Figure 4, but with a plurality of groove-like grooves 5 extending longitudinally distributed around the circumference. The arrangement of the grooves 5 is clearly visible in the cross-sectional view of Figure 6. The grooves 5 further reduce the friction between the catheter tube 1 and the spiral support structure 2. Furthermore, such longitudinal grooves are helpful for detecting blood flow through the catheter tube 1.

[0101] As can be seen in particular from Figure 6, the inner diameter of the opening 7 can be smaller than the outer diameter of the spiral support structure 2. Accordingly, the spiral support structure 2 cannot emerge from the opening 7.

[0102] The spiral support structure 2 can be formed, for example, from a metal wire or another suitable material. For example, a round material or a flat material, e.g. with a rectangular or square cross-section, can be used. The material of the spiral support structure 2 can be solid or hollow on the inside. Figures 7 to 9 explain a further embodiment of a medical access system in which the spiral support structure 2 can be removed from the catheter tube 1. Figure 7 shows the medical access system in the as-delivered state, i.e. all components are in an assembled starting position. It can be seen that the medical access system has an additional module, namely a support module 10, of which only a housing 11 of the support module 10 can be seen in Figure 7. The housing 11 is coupled to the housing 20 of the catheter 29 via fastening elements.The handling element 32 of the needle device 39 is then located at the end of the housing 11 of the support assembly 10 remote from the patient.

[0103] Figure 8 shows the medical access system according to Figure 7 in a kind of exploded view, so that the individual components can be seen. The components present are thus the catheter 29, support assembly 10, and needle device 39. It can be seen that the spiral support structure 2 is fixed to the housing 11 or another part of the support assembly 10. If the housing 11 is detached from the housing 20, e.g., by a rotating movement, the housing 11 can be removed from the catheter 29 assembly together with the spiral support structure 2. The needle device 39 can be removed from the support assembly 10 in a similar manner.

[0104] Figure 9 shows once again the complete support assembly 10 with the spiral support structure 2 after its removal from the catheter 29. For example, an identically shaped new support assembly 10 can now be attached to the catheter 29, ie the new spiral support structure 2 is inserted into the catheter 1.

[0105] Alternatively, a differently designed support assembly can also be attached to the catheter 29, e.g. an embodiment according to Figure 10. In the embodiment of Figure 10, an additional component in the form of a tubular section 12 is attached to the end of the spiral support structure 2 closest to the patient, e.g. by injection molding, welding, plugging and / or gluing. This additional tubular section 12 extends the spiral support structure 2 at the end closest to the patient to such an extent that, when plugged into the catheter tube 1, at least part of the tubular section 12 protrudes therefrom, as Figure 11 illustrates. With such a tubular section 12 protruding from the catheter tube 1 at the end closest to the patient, a venous valve can be bridged, for example.

[0106] In the case where a tubular inner body 3 is located within the spiral support structure 2, this can be extended at the end closest to the patient to such an extent that it forms a tubular section 12 protruding from the catheter tube 1 at the end closest to the patient. The tubular inner body 3 then protrudes a significant distance from the spiral support structure 2 at the end closest to the patient.

[0107] The tubular inner body 3 or at least the tubular section 12 can be made of plastic, for example, optionally with a barium additive or inserted markers of another material to produce improved X-ray visibility.

[0108] Figure 11 shows the catheter 29 with the support assembly 10 attached thereto according to Figure 10. It can be seen that the tubular section 12 protrudes from the catheter tube 1.

[0109] List of reference symbols

[0110] 1 catheter tube

[0111] 2 spiral support structure

[0112] 3 tubular inner body

[0113] 4 Free space

[0114] 5 grooves

[0115] 6 Dilation section

[0116] 7 axial opening

[0117] 10 Support assembly

[0118] 11 Support assembly housing

[0119] 12 tubular section

[0120] 15 tubular outer body

[0121] 20 housings

[0122] 21 Tube exit area

[0123] 23 fixing wings

[0124] 25 needle opening

[0125] 29 catheters

[0126] 30 puncture needles

[0127] 31 lace

[0128] 32 Handling element

[0129] 34 locking element

[0130] 39 Needle device

[0131] 40 cap

[0132] L longitudinal direction

Claims

Patent claims 1. A medical access system for providing access to a hollow body of a patient, the access system comprising at least one catheter (29) with a tubular catheter tube (1), the catheter (29) being configured, after a puncture of a sheath of the hollow body to be punctured, to be pushed over at least part of the length of the catheter tube (1) through an opening created by means of a puncture needle (30) or in some other way through the sheath of the hollow body and to remain there for a period of time, characterized in that at least the part of the catheter tube (1) which is configured to remain in the hollow body has, over its entire length or the predominant part of its length, at least one spiral-shaped support structure (2), in particular in the form of at least one spirally wound, internally hollow guide wire.

2. Medical access system according to claim 1, characterized in that the spiral support structure (2) is arranged loosely in the catheter tube (1) over the predominant part of its longitudinal extent or its entire longitudinal extent.

3. Medical access system according to one of the preceding claims, characterized in that the spiral support structure (2) is permanently fixed to the catheter tube (1) or a component of the medical access system connected thereto via at least one fastening element.

4. Medical access system according to claim 3, characterized in that the spiral support structure (2) is fixed at one of its ends or at both ends via at least one fastening element to the catheter tube (1) or a component of the medical access system connected thereto and is otherwise arranged loosely in the catheter tube (1). Medical access system according to one of the preceding claims, characterized in that the helical support structure (2) increases the bending section modulus and / or the radial section modulus of the catheter tube (1). Medical access system according to one of the preceding claims, characterized in that a tubular inner body (3) is arranged within the helical support structure (2). Medical access system according to one of the preceding claims, characterized in that the helical support structure (2) is detachably attached to the catheter tube (1) or a component of the medical access system connected thereto and can be removed from the catheter tube (1) if necessary.Medical access system according to one of the preceding claims, characterized in that the medical access system has, as a further assembly, a support assembly (10), which is present in addition to the catheter (29) and is detachably coupled to the catheter (1), for example to a housing (20) of the catheter (1), wherein the support assembly (10) has the spiral support structure (2). Medical access system according to claim 8, characterized in that the spiral support structure (2) is permanently fixed to a part of the support assembly (10), for example to a housing (11) of the support assembly (10). Medical access system according to one of the preceding claims, characterized in that the spiral support structure (2) has a plurality of spiral turns that lie directly against one another.Medical access system according to one of the preceding claims, characterized in that the spiral support structure (2) has a plurality of spiral turns which are loosely adjacent to one another but are not fastened to one another. Medical access system according to one of the preceding claims, characterized in that the spiral support structure (2) or its spiral windings are provided with a friction-reducing coating, in particular a PTFE coating. Medical access system according to one of the preceding claims, characterized in that the spiral support structure (2) extends only over part of the longitudinal extent of the catheter tube (1). Medical access system according to one of the preceding claims, characterized in that the catheter tube (1) terminates at the end closest to the patient with an axial opening (7), the inner diameter of which is smaller than the outer diameter of the spiral support structure (2) or at least of the end region of the spiral support structure (2) closest to the patient.Medical access system according to one of the preceding claims, characterized in that the catheter tube (1) has, on the inside and distributed over the circumference, a plurality of groove-like grooves (5) extending linearly or helically in the longitudinal direction. Medical access system according to one of the preceding claims, characterized in that a tubular section (12) protrudes from the spiral support structure (2) at the end closest to the patient, which protrudes from the catheter tube (1) at the end closest to the patient through an axial opening (7) formed at the free end of the catheter tube (1).Medical access system according to one of the preceding claims, characterized in that the medical access system is designed as an indwelling cannula for puncturing a hollow body of a patient by means of a puncture needle (30), wherein the indwelling cannula has at least the catheter (29) with the tubular catheter tube (1), in which the puncture needle (30) can be guided in a longitudinally displaceable manner, wherein the catheter (29) is set up, after carrying out a puncture of a sheath of the hollow body to be punctured, over at least part of the length of the catheter tube (1) through the by means of. The puncture needle (30) is designed to be pushed through the shell of the hollow body to be punctured and to remain there for a period of time. A medical access system according to one of the preceding claims, characterized in that the spiral-shaped support structure (2) consists predominantly or entirely of one or more plastic materials.

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