Sheath assembly for inserting a string-shaped element, in particular a catheter, into a patient's body - Patents.com

Abstract

To provide a sheath assembly for at least partially inserting a cord-shaped element into the body of a patient.SOLUTION: A sheath assembly for the insertion of a cord-shaped element (32, 105), comprises an introducer sheath (101) and an auxiliary sheath (104) for insertion into the introducer sheath (101) together with the cord-shaped element (32, 105), with first fastening means (106) for detachably fastening the auxiliary sheath to the introducer sheath, and with second fastening means (107) for detachably fastening the cord-shaped element to the auxiliary sheath, where the introducer sheath (101) has a first sheath housing (13, 114) and a distal tubular section (11, 41a) that terminates in the first sheath housing, and a first flushing device (108), where the auxiliary sheath (104) has a second sheath inner chamber (111), a distal, tubular part (112) and a second flushing device (109).SELECTED DRAWING: Figure 17

Description

[Technical Field]

[0001] The present invention relates to the field of construction and can be used with particular advantage in the field of medical technology, and in particular to a sheath assembly for at least partially inserting a string-shaped element, in particular a catheter, into the body of a patient. [Background technology]

[0002] The use of an introducer sheath for the purpose of inserting a catheter into a patient's body, for example, into a blood vessel, is known in principle, with the proximal end of the sheath protruding from the patient's body while the distal end remains inside the patient's body. Such an introducer sheath may, for example, be designed as a single piece, but may also be simply inserted under sterile conditions through the skin or through an orifice in the patient's body. For example, such a sheath is advantageous when a catheter is inserted into and removed from a patient's blood vessel. One particular application of such a catheter involves a catheter having a functional element, for example, a hollow catheter with a blood pump located at one end, which is transported intravascularly to a ventricle or a large blood vessel, where it is optionally expanded. Suitable blood pumps capable of expansion and subsequent recompression are known in the literature in many forms.

[0003] However, other devices, such as surgical ablation devices for removing deposits within blood vessels or the like, may also be attached to the catheter as functional elements.

[0004] In the '611 patent, a catheter introducer system includes a catheter sheath having a valve for providing a friction fit on the catheter.

[0005] U.S. Patent No. 5,999,623 discloses a vascular introducer including a proximal hub portion having an internal bore, an elongate sheath extending distally from the hub portion and having an inner lumen in communication with the internal bore of the hub portion, and a hemostatic valve disposed within the bore of the hub portion. The hemostatic valve has a passage extending therethrough and includes a sealing flap movable between an open position relative to the passage and a closed position relative to the passage.

[0006] Patent Document 3 relates to a catheter system including an introducer having a body, an introducer sheath protruding from the body, and a first seal supported within the introducer; and a catheter having a body, an outer sheath protruding from the body, a second seal supported within the catheter, and an inner core configured to axially advance the body, second seal, and outer sheath. The introducer can be configured to be selectively matable with the catheter so that the catheter can be selectively and detachably axially coupled to the introducer. The catheter system can also be configured so that the catheter can rotate relative to the introducer when the introducer and catheter are coupled. The introducer can be configured to radially constrain the endoluminal prosthesis.

[0007] Regarding the insertion of a catheter pump, it has already been proposed in Patent Document 4 and elsewhere to use an auxiliary sheath in addition to an introducer sheath, in which a catheter having a compression pump is inserted into the auxiliary sheath, and the auxiliary sheath temporarily holds the end portion of the catheter and the compression pump and is inserted into the introducer sheath together with the pump.

[0008] It is known to provide an internal sheath cleaning device in the sheath interior, where the article is inserted into the sheath, which device can be used to clean the element to be inserted and / or the sheath entrance before or during insertion to prevent bacteria and / or air from entering the patient's body. It is also known to provide a sheath of this type with a sealing device, on the one hand to prevent blood or other body fluids from escaping from the sheath before the insertion of the element through the sheath, and on the other hand to seal to the greatest extent possible the opening through which the element is inserted from the area outside the opening during the insertion of the element into the sheath. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] U.S. Patent Application No. 2004 / 0147877A1 [Patent Document 2] U.S. Patent Application No. 2008 / 0097386A1 [Patent Document 3] U.S. Patent Application No. 2010 / 0004730A1 [Patent Document 4] European Patent No. 2399639A1 Summary of the Invention [Problem to be solved by the invention]

[0010] In view of the above-mentioned prior art, the object of the present invention is to devise a sheath assembly comprising an introducer sheath and an auxiliary sheath, which generally prevents bacteria or other unwanted objects and substances from entering the patient's body to the greatest extent possible, by allowing the insertion of a string-shaped element, in particular a catheter, into the introducer sheath by means of the auxiliary sheath in the most comfortable manner possible. The sheath assembly is also protected to the greatest extent possible against the escape of body fluids. Furthermore, trauma to the patient is minimized as much as possible, so that the outer diameter of the introducer sheath exceeds as little as possible the outer diameter of the (optionally compressed) functional element and / or catheter. [Means for solving the problem]

[0011] This problem is solved by the features specified in this application.

[0012] This solution requires a sheath assembly for inserting a string-shaped element, in particular a catheter, into a patient's body, comprising an introducer sheath having a distal end provided for insertion into the patient's body and a proximal end that protrudes from the patient's body when the distal end is inserted into the patient's body, and an auxiliary sheath for insertion into the introducer sheath together with the string-shaped element / catheter, with first fastening means for fastening, in particular detachably, the auxiliary sheath to the introducer sheath and second fastening means for fastening, in particular detachably, the string-shaped element to the auxiliary sheath, the introducer sheath having a first internal chamber with a first receiving passage for the string-shaped element and a first cleaning device for cleaning the sheath internal chamber, and the auxiliary sheath having a second sheath internal chamber with a second receiving passage for the string-shaped element and a second cleaning device for the second sheath internal chamber. For example, this solution requires a sheath assembly for inserting a string-shaped element, in particular a catheter, into a patient's body, comprising an introducer sheath with a distal end provided for insertion into the patient's body and a proximal end protruding from the patient's body when the distal end is inserted into the patient's body, and comprising an auxiliary sheath for insertion into the introducer sheath together with the string-shaped element / catheter, and comprising first fastening means for fastening the auxiliary sheath in a particularly detachable manner to the introducer sheath and second fastening means for fastening the string-shaped element in a particularly detachable manner to the auxiliary sheath, The sheath has a first sheath housing, a first sheath inner chamber having a first receiving passage for the string-shaped element, a distal tubular section terminating in the first sheath housing, and a first cleaning device mounted in the housing for cleaning the sheath inner chamber; the auxiliary sheath has a second sheath inner chamber having a second receiving passage for the string-shaped element, a distal tubular section, and a second cleaning device for the second sheath inner chamber; and the first sheath housing has means for positioning the distal end of the tubular section of the auxiliary sheath in the first sheath housing and proximally forward of the proximal end of the tubular section.

[0013] The sheath assembly according to the invention ensures that the auxiliary sheath can be permanently and securely attached to the introducer sheath and that the introducer sheath and the auxiliary sheath can thus be cleaned and kept clean and sterile. Inside the introducer sheath, the interior space between the auxiliary sheath and the introducer sheath and / or between the distal part of the auxiliary sheath and the introducer sheath is cleaned and kept sterile. Inside the auxiliary sheath, the inner area of ​​the auxiliary sheath along with the string-like elements attached to or projecting from this area, in particular the catheter, is cleaned and kept sterile. This results in an entire assembly that is permanently and mechanically held together at least until the connection between the introducer sheath and the auxiliary sheath is intentionally released, allowing for easy cleaning of the transitions from the introducer sheath to the auxiliary sheath and from the auxiliary sheath to the string-like elements attached thereto. In this way, it can be ensured, on the one hand, that the number of pathogens and / or other contaminants entering the introducer sheath from the outside is minimized, while at the same time preventing blood from leaking out of the introducer sheath and the auxiliary sheath.

[0014] Advantageously, the means for positioning the tubular section of the auxiliary sheath inside the introducer sheath comprise a cylindrical passageway inside the introducer sheath, the diameter of which corresponds to the diameter of the tubular section of the auxiliary sheath or does not substantially deviate from this diameter, i.e., not more than 30%, in particular not more than 15%. A radially inwardly projecting annular land, forming an axial stop or an axial stop of a different configuration, may also be provided in the form of a reduced diameter section of the passageway for the tubular section of the auxiliary sheath. The corresponding land leaves a rounded opening, the diameter of which corresponds to the inner diameter of the tubular section of the auxiliary sheath or does not substantially deviate from this diameter, i.e., not more than 30%, in particular not more than 15%. Such an axial stop may be offset and therefore located within the tubular section of the introducer sheath. It is possible to design the system so that the auxiliary sheath is inserted into the tubular section of the introducer sheath only far enough so that the auxiliary sheath itself remains proximal to the opening in the patient's skin. In this way, the diameter of the introducer sheath only minimally exceeds the diameter of the functional elements of the compressed catheter, minimizing trauma and bleeding risk to the patient.

[0015] In another further development, the inner diameter of the tubular section of the auxiliary sheath is also larger than the inner diameter of the tubular section of the introducer sheath, so that the functional element is compressed in two stages. Initially, in a first step, as the catheter advances into the auxiliary sheath, the functional element is compressed to the inner diameter of the auxiliary sheath. Once transported to the introducer sheath, the diameter of the functional element is further compressed until it corresponds to the inner diameter of the introducer sheath. This two-stage compression ensures that the force for compressing the functional element does not exceed a critical value, at which point the connection of the functional element to the catheter may, for example, be broken. The same applies analogously to sheaths with non-circular cross sections, for example sheaths with oval or elliptical cross sections.

[0016] In one advantageous embodiment of the invention, it is provided that the auxiliary sheath has a tubular distal part and a proximal sheath housing, and that only the tubular part is connected, in particular detachably, to the introducer sheath.

[0017] In this case, an advantageous assembly is constructed such that the tubular section of the auxiliary sheath is clamped in a simple manner inside the introducer sheath and thus detachably fastened, and the difference in concentricity of the tubular sections of the sheaths relative to one another in the clamping region is no more than 30% of the diameter of the larger inner sheath, and particularly preferably no more than the difference in the diameters of the sheaths. This helps to avoid the need for the string-shaped element / catheter to cross edges that would result from the difference in diameter and that could damage the string-shaped element / catheter during transfer from the auxiliary sheath to the introducer sheath. Inside the auxiliary sheath, the exterior of the tubular section of the auxiliary sheath is kept sterile by a cleaning device, and the interior of the introducer sheath is kept sterile by a cleaning device. For example, a string-shaped element / catheter equipped with a compressed blood pump can be stored inside this section while the tubular section of the auxiliary sheath is inserted into the introducer sheath. When the tubular section of the auxiliary sheath is inserted into the introducer sheath, a blood pump can be transferred from the auxiliary sheath to the introducer sheath, for example, into the tubular section of the introducer sheath. In this process, the interior of the introducer sheath is cleaned, thereby simultaneously ensuring sterility of the surrounding area during the transfer process.

[0018] The sterile tube, in which the tubular portion of the auxiliary sheath is arranged, can be attached in a fluid-tight manner to the end face of the introducer sheath. The sterile tube ends in a fluid-tight manner in the auxiliary sheath, in particular its housing. The sterile tube is compressed axially so that the auxiliary sheath, in particular its tubular portion, is pressed against the introducer sheath and rests thereon once the string-shaped element has been inserted into the introducer sheath. The sterile tube can be embodied, for example, as a corrugated tube.

[0019] In a further advantageous embodiment of the invention, it is provided that the auxiliary sheath has a tubular distal portion and a sheath housing, and that the sheath housing of the auxiliary sheath is in particular detachably connected to the introducer sheath, in particular to the sheath housing of the introducer sheath.

[0020] When the sheath housing of the auxiliary sheath is fixedly connected to the sheath housing of the introducer sheath, a generally solid and non-deformable unit is obtained, which is particularly easy to handle in the patient's body and also particularly easy to insert the string-shaped element from the auxiliary sheath into the introducer sheath. Once the auxiliary sheath is connected to the introducer sheath, the sheath assembly acts as a single multi-stage sheath.

[0021] The present invention can be further advantageously embodied by connecting the auxiliary sheath to the introducer sheath in the form of a clamping connection with a detachable force or friction coating, a double cone connection, a threaded connection, a bayonet connection, a press-fit connection, or other detachable engagement connection. This type of detachable connection is easy to manufacture and releases again under surgical conditions. Due to its simple mechanical function, no chemical bonding agents are required, so there is no risk of contamination when used on a living patient. The associated connection can be easily released exactly as it was produced.

[0022] Specific examples of corresponding detachable connections are specified in further detail below with respect to example embodiments.

[0023] The invention can be further advantageously implemented by connecting a second washing device to the first washing device. In this case, it is particularly conceivable that the same fluid is used in both washing devices, since fluids are exchanged between them. This reduces costs and increases the assurance of sterility. For example, the same pump may be used in the first and second washing devices to move the washing fluid.

[0024] In this case, it is conceivable and advantageous for the interior of the sheath housing of the auxiliary sheath to be directly connected to the first cleaning device by an auxiliary cleaning passage. In one implementation, the auxiliary cleaning passage can extend, for example, in the form of a hose or tube attached to the outer periphery of the housing of the auxiliary sheath. In this case, the cleaning device of the auxiliary sheath and the cleaning device of the introducer sheath have the same design, and only the two cleaning passages are connected to each other.

[0025] However, it is also conceivable and advantageous for the auxiliary flushing passage to extend directly from the sheath housing of the introducer sheath to the interior of the tubular portion of the auxiliary sheath, in particular through an opening in the outer surface of the tubular portion of the auxiliary sheath. Thus, the tubular portion of the auxiliary sheath has an opening in its outer surface through which flushing fluid can flow, so that the interior of the auxiliary sheath, in particular the interior of the tubular portion of the auxiliary sheath, can be flushed in the inner chamber of the sheath housing of the introducer sheath, together with the outer region of the auxiliary sheath located inside the introducer sheath. Advantageously, the flushing fluid then flows axially along the tubular portion of the auxiliary sheath, flushing the auxiliary sheath as a whole unit.

[0026] In this case, the flushing fluid can move from the introducer sheath to the sheath housing of the auxiliary sheath and, in principle, between the auxiliary sheath and the string-shaped element / catheter placed therein, so that such catheter / string-shaped element is also kept sterile. This catheter / string-shaped element is inserted into the patient's body, and therefore the string-shaped element itself / catheter must be kept sterile.

[0027] In a further advantageous embodiment of the invention, in the case of a direct connection between the sheath housing of the auxiliary sheath and the sheath housing of the introducer sheath, the auxiliary flushing passage extends into the connection area, in particular through a wall region of the sheath housing of the auxiliary sheath that is located within the introducer sheath or through a wall portion of the introducer sheath housing that is surrounded by a portion of the auxiliary sheath. In this embodiment, a fixed, channel-like connection is formed between the inner chamber of the introducer sheath and the inner chamber of the auxiliary sheath housing, thereby ensuring the transfer of flushing fluid between the inner chambers of the two sheath housings. In addition, at least one opening is provided on the outer surface of the auxiliary sheath housing, which can serve either for the discharge of flushing fluid or for ventilation.

[0028] Alternatively or additionally, a hypodermic needle may be attached to the distal end of the secondary sheath, e.g., so that when the secondary sheath is inserted into the introducer sheath, it penetrates a rubber gasket, e.g., a dome gasket or plate gasket, of the introducer sheath and protrudes into the interior of the wash chamber of the introducer sheath, thereby forming a communication passage between the interior chamber of the introducer sheath housing and the housing of the secondary sheath through the hollow chamber of the needle.

[0029] In one advantageous embodiment of the invention, it is conceivable that the introducer sheath and the auxiliary sheath abut against each other as connecting mates in an annular region, that a circumferentially extending annular or arcuate circumferential groove is provided in at least one of the two connecting mates in the annular region, and that both the sheath housing of the introducer sheath and the sheath housing of the auxiliary sheath are provided with a channel-like recess that connects the interior of the sheath in a connecting state with the circumferential groove, in this case the housing part of the introducer sheath surrounds the housing part of the auxiliary sheath in the connecting region or vice versa.

[0030] The channel-like recesses in the housing, particularly the housing wall, of the introducer sheath and the housing, particularly the housing wall, of the auxiliary sheath are connected to one another by an annular or arcuate passage, so that even a rotation of the auxiliary sheath relative to the introducer sheath will not prevent the establishment of the connection between the channel-like recesses. This results in high reliability in establishing the connection between the irrigation chambers of the introducer sheath and the auxiliary sheath as soon as the two housings are connected to one another, regardless of the relative rotation of the parts. In this regard, the channel-like recesses and / or the circumferential passage can be configured such that at least the passage provided in the introducer sheath housing, particularly both passages, are closed by a sliding element as soon as the two sheath housings are separated from one another.

[0031] In the following, the invention will be specified with reference to example embodiments illustrated in a set of drawings, which will be explained in more detail below: First, possible ways of fixing the auxiliary sheath to the introducer sheath or the catheter to the auxiliary sheath will be explained, after which the combination of the cleaning device and the fastening of the two sheaths together will be specified in more detail. [Brief explanation of the drawings]

[0032] [Figure 1] 1 is a schematic diagram of the cardiovascular system with a sheath inserted. [Figure 2] FIG. 2 is a detailed view of a section of FIG. [Figure 3] FIG. 1 shows an embodiment of the present invention having a first sheath (introducing sheath) and a second sheath (auxiliary sheath). [Figure 4] 1 illustrates an embodiment of a pump. [Figure 5] FIG. 10 is a view showing the second sheath (auxiliary sheath) from which the pump has been removed. [Figure 6] FIG. 10 is a diagram showing the pump being stored in the second sheath (auxiliary sheath). [Figure 7] FIG. 10 is a diagram showing the pump being stored in the second sheath (auxiliary sheath). [Figure 8] FIG. 10 shows the transfer of the pump from the second sheath to the first sheath (introducer sheath). [Figure 9]FIG. 10 shows the transfer of the pump from the second sheath to the first sheath (introducer sheath). [Figure 10] 1 is a longitudinal cross section showing a sheath housing having a tubular section. [Figure 11] 1 is a longitudinal cross-section of a portion of a sheath housing having a cutting device. [Figure 12] 1 is a longitudinal section showing a sheath housing with a clamping device for a tubular section and an additional clamping device. [Figure 13a] 10 is a longitudinal cross section showing an alternative clamping ring having conical clamping pads. [Figure 13b] 1 is a longitudinal cross section showing a pinch connection each having a longitudinal groove and a bead on its outer surface. [Figure 13c] 1 is a longitudinal section showing a clamp connection with a clamp connection in the form of a threaded connection. [Figure 13d] 1 is a longitudinal section showing a clamping connection in the form of a conical connection including a bayonet sheath. [Figure 13e] FIG. 13d is a view of the cone of FIG. 13d rotated by 90°. [Figure 13f] 1 is a longitudinal section showing a luer cone connection with a threaded connection. [Figure 13g] 1 is a longitudinal section showing a clamping connection having a spring clip that is guided within a sheath housing and can be displaced laterally and expanded radially. [Figure 13h] 10A-10C show possible embodiments of the elements clamped in the area of ​​the clamping point; [Figure 13i] 13g in a side view, rotated 90° relative to FIG. 13g. [Figure 14] 10 is a longitudinal section showing a sheath housing with a clamping device for a proximally inserted string-shaped element. [Figure 15] FIG. 10 shows an introducer sheath and a secondary sheath coupled thereto, showing the two sheath cleaning devices coupled together. [Figure 16]FIG. 10 shows an introducer sheath and a secondary sheath coupled thereto, with the connection to the interior of the secondary sheath located inside the introducer sheath. [Figure 17] 10A and 10B show a sheath assembly in which the sheath housings of the auxiliary sheath and introducer sheath are fixedly connected. [Figure 18] FIG. 1 shows an introducer sheath including an auxiliary sheath that can be housed in a sterile tube. [Figure 19a] FIG. 1 shows an axial cross-section of an introducer sheath including an auxiliary sheath and a string-shaped element / catheter inside the auxiliary sheath, the auxiliary sheath extending inside the introducer sheath. [Figure 19b] FIG. 10 is an axial cross-sectional view of the auxiliary sheath with the string-shaped element / catheter inside the auxiliary sheath. [Figure 19c] FIG. 1 is an axial cross-sectional view of an introducer sheath with a string-shaped element / catheter inside the introducer sheath. DETAILED DESCRIPTION OF THE INVENTION

[0033] FIG. 1 shows a schematic diagram of the human cardiovascular system 1. Located in the groin area is a femoral artery 2, which connects via a major artery to the aortic arch 3 and then to a heart chamber 4. An introducer sheath 10 is first inserted into the femoral artery 2, for example, using the Seldinger technique. In this process, the femoral artery or some other blood vessel is first punctured, for example, using a steel cannula with a cutting edge. A guidewire 12 is then pushed through the puncture opening into the steel cannula and inserted retrogradely through the aortic arch 3 into the left ventricle 4. Once the puncture cannula is removed, a first sheath 10, embodied as an introducer sheath and including a tubular section 11 and an optional dilator (not shown), is threaded onto the guidewire and inserted through the puncture site into the cardiovascular system. The sheath is inserted a short distance into the lumen of the cardiovascular system or to the location where the inserted element will be located. A fluid pump is then inserted into the cardiovascular system through the introducer sheath 10.

[0034] The tubular section 11 of the first sheath 10 is inserted into the artery so that the proximal end of the first sheath 10 is located outside the femoral artery and protrudes from the patient's body, so that it can be used to insert, for example, a blood pump, which is then threaded onto the guide wire 12 and guided to the left ventricle with the aid of the guide wire.

[0035] It is also possible to guide the tubular portion / section 11 of the first / introducer sheath 10 guided by the guidewire into the left ventricle, and then remove the guidewire 12 from the first sheath. The pump unit can then be guided through the first sheath lumen into the vicinity of or into the left ventricle 4.

[0036] Although the above describes a method for inserting a pump into the left ventricle to support cardiac function, it will be readily apparent to one skilled in the art that a pump or any other functional element may be positioned and inserted elsewhere in the cardiovascular system of the body.

[0037] It goes without saying that rather than a blood pump / heart support pump, any other functional element, in particular a compressible and expandable element, can be inserted through the sheath by means of a catheter.

[0038] FIG. 2 shows the first sheath 10 passing through the body tissue from the outside to the lumen L of the femoral artery 2. G 1, where the first sheath is guided to the sheath housing 13. The first sheath in this example includes a tubular section 11 that is connected to the proximal side of the sheath housing 13. The tubular section 11 has an inner diameter d 11 The lumen L1 has a trumpet-shaped flaring at region 14 towards the proximal end of tubular section 11.

[0039] The sheath housing 13 includes a hemostatic valve, as is well known in the art. G This prevents the fluid held inside from flowing out through the lumen L1.

[0040] In the example of Figure 3, the first sheath 10 of Figure 2 is joined to a second sheath 20. Only the tubular section 21 of the second sheath 20 (auxiliary sheath) is shown, which has an inner diameter d 21 The distal end of the second sheath 20 has an outer diameter such that the end can be inserted into the sheath housing 13. However, the inner diameter d 21 is the inner diameter d 11 Greater than.

[0041] A pump (not shown) located inside lumen L2 is transferred from second sheath lumen L2 to first sheath lumen L1 by applying pressure. The pump is transported through first sheath lumen L1 to a site within the cardiovascular system where the pump will be deployed. In this step, the pump can be guided over a guidewire or inserted into the first sheath lumen without a guidewire. To protect the shaft catheter along with the pump and the vessel wall, the first sheath is advanced distally to the site of pump deployment before the pump is pushed out.

[0042] One possible embodiment of the pump 30 will be described in more detail with reference to Figure 4. The pump 30 includes a distal pump unit 31 and a shaft catheter 32 attached to the proximal end of the distal pump unit 31. The shaft catheter 32 has a coupling at its proximal end (not shown) for connecting the shaft catheter 32 to a drive unit. The drive unit is located outside the patient's body and rotates a flexible shaft extending inside the shaft catheter 32, which in turn drives the distal pump unit 31. However, the present invention is also suitable for implementing pumps that are operated in a different manner (e.g., by an electric motor located in the pump or by an air turbine disposed in the pump).

[0043] The distal pump unit includes a pump housing 33 fabricated from crossed nitinol braces. A portion of the nitinol housing includes a coating 34 extending distally and proximally to a rotor 35 disposed inside the housing 33. The rotor is connected to a shaft 36 that extends into the shaft catheter 32 and rests thereon during rotation. The housing and rotor are compressible, meaning the pump is an automatic vacuum pump. The distal pump unit expands as it is pushed out of the distal end of the sheath. To compress the pump in preparation for implementation, the distal pump unit is housed in the distal end of the sheath lumen of a secondary sheath (auxiliary sheath). This sheath lumen has an inner diameter larger than the outer diameter of the shaft catheter.

[0044] In particular, the rotor may be axially displaceable relative to the pump housing by axial displacement of the drive shaft, or conversely, the rotor may be axially fixed relative to the pump housing.

[0045] The pump optionally has a discharge tube 37 defining a flow path for the fluid to be delivered, located proximal to the rotor 35. Located at the proximal end of the discharge tube 37 is an outlet opening, not described in detail.

[0046] Of course, the pump is also switched from supply to suction operation so that the pump does not conduct fluid from the distal end to the proximal end and vice versa.

[0047] A more detailed description of a suitable pump can be found, for example, in document EP 2 047 872 A1.

[0048] The functionality of the system will now be specified in more detail with reference to Figures 5 to 9.

[0049] FIG. 5 shows a pump 30' substantially corresponding to the pump 30 according to FIG. 4. For the sake of simplicity, the details of the pump are not shown. The bulbous housing and the "pigtail" located distal to the bulbous housing to prevent the heart pump from being sucked into the heart wall are shown. A shaft catheter 32' extends proximally relative to the distal pump unit 31'. A second sheath 20' is disposed surrounding a region 38' of the shaft catheter 32', this sheath having an inner lumen L2 and an inner diameter d 21 is smaller than the diameter of the distal pump unit 31' in the expanded state.

[0050] The pump 30′ shown in FIG. 5 is a compressible pump; in other words, the distal pump unit 31′, including the pump housing and rotor mounted thereon, is embodied so that it can be compressed, i.e., its diameter can be reduced. Once a quality assurance inspector, e.g., a physician, confirms proper function of the pump 30′, such as by observing the rotational movement of the rotor unit mounted on the distal pump unit 31′ during a test operation, the distal pump unit 31′ is retracted into the lumen L2 of the second sheath 20′ by pulling the shaft catheter 32′ proximally. Retracting the pump into the second sheath 20′ avoids bending and / or damage to the shaft catheter and / or the shaft mounted therein. The pump 30' and the secondary sheath 20' surrounding the region 38' of the shaft catheter 32' shown in FIG. 5 form a system 200 that allows for functional testing of the pump 30' in time before operation and for compressing the pump by pulling the distal pump unit 31' towards the distal end of the secondary sheath 20' to avoid damage to the shaft.

[0051] While the system may include both active and automatic vacuum pumps, automatic vacuum pumps, ie, pumps in which the distal pump unit automatically returns to its original dimension outside the sheath, are particularly suitable.

[0052] 6 shows an intermediate step during retraction of the distal pump unit 30' into the lumen of the secondary sheath 20'. It is apparent that the distal pump unit 30' can be housed in the lumen of the secondary sheath 30' because the distal pump unit 30' is compressible and can have a small diameter.

[0053] Also shown in FIG. 6 is a coupling 39′ attached to the shaft catheter 32′, which allows a shaft extending therethrough to be coupled to a drive unit. The outer diameter of the coupling 39′ is frequently larger than the inner diameter of the lumen L2, and in most instances, the secondary sheath 20′ is pushed distally from the proximal end of the shaft catheter 32′ prior to attachment of the coupling 39′, so that the system 200 delivers a pump with the secondary sheath 20′ mounted proximal to the distal pump unit 31′ and the coupling 39′ pre-attached. FIG. 6 also shows a slight flare at the distal end of the secondary sheath 20′. The trumpet-shaped extension 24′ facilitates insertion of the distal pump unit 31′ into the lumen L2 of the secondary sheath 20′.

[0054] Finally, in FIG. 7, the distal pump unit 31′ is located entirely inside the lumen L2 of the secondary sheath 20″. The secondary sheath 20″ has two pre-attached gripping units 22″ that allow for good retention and / or removal of the secondary sheath 20″ as the pump unit 31′ is retracted into the lumen L2 and / or good subsequent peeling away. However, according to the invention, it may also be advantageous to use an auxiliary sheath that remains permanently connected to or is retained by the introducer sheath. If a “pigtail” is provided, this may likewise be retracted into the lumen L2, so that the distal pump unit 31′ is located inside the lumen L2, with the pump components located distally to the distal pump unit 31′.

[0055] FIG. 8 illustrates how the system 200, consisting of the pump 30′ and the second sheath 20″, is assembled in active connection with the first sheath 10 to form the system 100. First, the second sheath 20″ (auxiliary sheath) is inserted at its distal end into the sheath housing of the first sheath 10 (introducing sheath). As soon as the distal tip of the second sheath 20″ reaches the opening of the tubular section of the first sheath 10, the pump is transferred from the second sheath 20′ to the first sheath 10′ by pushing the pump distally, which is achieved by applying pressure to the shaft catheter 32′. In this process, the diameter of the distal pump unit 31′ is increased to the inner diameter d of the lumen L1. 11 It is further reduced to

[0056] 9 shows the next step in which the distal pump unit 31′ is positioned entirely inside the lumen L1 of the first sheath 10. The fact that the distal pump unit 31′ is positioned entirely inside the lumen L1 of the first sheath 10 can be indicated by, for example, color markings 50 applied to the outside of the shaft catheter 32′.

[0057] Assuming that the secondary sheath 20" is embodied as a "peel-away" sheath, the secondary sheath is optionally removed from the shaft catheter 32' by peeling the peel-away sheath from the proximal end to the distal end, away from the shaft catheter 32'. The directional peeling from the proximal end to the distal end may be assisted by notch A, but may be primarily due to the orientation of the molecular chains of the plastic used in the proximal to distal direction.

[0058] Once the sheath has been removed, the pump 30' is optionally further guided inside the lumen L1 of the first sheath 10 to the desired location.

[0059] Optionally, the first sheath can be pushed forward with the distal sheath opening proximal to the deployment site before or after the pump is inserted, the length of the first sheath being sufficient for this purpose.

[0060] Reinforcement of the second sheath 20" is not necessary, particularly when the distal pump unit 31' is housed in the distal end of the second sheath lumen L2, as the risk of shaft breakage during the pulling action is substantially reduced.

[0061] As shown in Figures 7 to 9, since the pump is transferred from the second sheath to the first sheath, the second sheath may include a reinforcing structure in the form of an insertion wire, or the tubular section 21" of the sheath 20" may be made of rigid plastic or metal rather than flexible plastic.

[0062] A further option for stabilizing the pump and secondary sheath involves holding the secondary sheath 20″ as the pump 30′ is pushed distally forward, particularly as the pump 30′ is transferred from the secondary sheath to the first sheath, by a support device 40 in the form of a stable outer sleeve and / or as a receiving channel in the introducer sheath.

[0063] Another possible variation of the method for inserting a pump into the left ventricle of the heart is described below. As a preparatory measure, the pump is first filled with sterile physiological saline, thus completely expelling any air. Then, an auxiliary sheath, located adjacent to the distal pump unit, is pushed forward into the discharge tube, if provided. The auxiliary sheath has a diameter of, for example, 10 Fr. Once the auxiliary sheath is advanced to the discharge tube, it is surrounded by a sleeve-like support device. Then, by applying a proximal pulling motion to the shaft catheter, and optionally by a slight rotational motion, the distal pump unit is retracted into the auxiliary sheath. The pump is pushed further into the auxiliary sheath so that the existing pigtail is likewise concealed inside the auxiliary sheath. These steps allow for testing of the pump's proper function prior to surgery, and for the pump to be inserted into the sheath immediately after testing, without the need for such operations under time constraints. For example, the vascular system is perforated to insert the first sheath immediately after testing. However, to save time, an assistant can thus prepare the pump while the surgeon performs the drilling in parallel.

[0064] Once the 9Fr introducer sheath has been inserted into the left ventricle of the heart, the dilator, if present, is optionally withdrawn from the introducer sheath and removed.

[0065] The pump, held inside the auxiliary sheath and initially surrounded by, for example, a sleeve, is then pushed into the sheath housing of the introducer sheath until the tip of the auxiliary sheath hits a mechanical stop. The pump is then transferred from the auxiliary sheath into the tubular section of the introducer sheath by applying pressure to the shaft catheter. Once the entire distal pump unit has been transferred into the introducer sheath, as can be determined, for example, based on optional markings on the shaft catheter shaft, the auxiliary sheath is left inside the introducer sheath, or optionally, the peel-away sheath is peeled away and removed from the shaft catheter. The pump is then pushed forward inside the first sheath (introducer sheath) to the left ventricle. The first sheath is then retracted from the left ventricle to the beginning of the descending aorta.

[0066] The positioning of the distal pump unit in the left ventricle can be confirmed, for example, by X-ray imaging. For this purpose, X-ray-detectable markings can be placed on or near the pump housing, e.g., on the catheter, or the pump housing itself can be detected by X-ray. The outlet area of ​​the pump, i.e., the outflow opening of the discharge tube, should also be located in the area of ​​the ascending aorta. This can also be confirmed by X-ray-detectable markings. If present, the pigtail catheter tip should contact the tip of the left ventricle.

[0067] To remove the pump from the ventricle, the pump is pulled back into the introducer sheath by applying traction to the shaft catheter, and compressed and removed from the arterial vasculature. If the first sheath is already shortened, the pump is first pulled a short distance back into the shaft catheter to compress it. For this purpose, the shaft catheter may have a retraction funnel on the drive shaft in which the pump is retracted by pulling. The first sheath and the remaining components are then removed from the cardiovascular system.

[0068] The use of an elongated sheath for implantation and explantation of the pump according to the present invention, particularly as an introducer sheath, is particularly advantageous. The elongated sheath not only serves to insert the pump into a lumen inside the body, as is customary in the prior art, but also to guide the pump through the lumen of the sheath to the area of ​​the placement site. In this regard, in the medical field, it is advantageous for the sheath to have a length between 40 and 120 cm. This length is determined by the subsequent site of placement of the pump and the size of the patient.

[0069] Once the pump, along with the elongate sheath, is removed from the body lumen, a pressure bandage is used to stop bleeding from the femoral artery. Alternatively, the pump can be removed from the lumen of the elongate sheath. An additional guidewire can then be positioned through the lumen of the sheath, and once the sheath is removed, a device for closing the hole can be guided over this wire, resulting in improved hemostasis.

[0070] 10 to 13 demonstrate variations of the first sheath according to the invention having one or more clamping devices for securing the tubular section 41 to the sheath housing 43. FIG.

[0071] 10 also shows a longitudinal section of the sheath housing 43, which has substantially the form of a cylindrical sleeve that is closed at least at its distal end 44, facing away from the patient's body, by a pressure screw 45. The sheath housing 43 has a continuous receiving passage 46 for the sheath tubular section 41. In the view of FIG. 10, the tubular section 41 is marked with a solid line up to the irrigation chamber 47 of the receiving passage 46, and from there proximally with a dotted line. This indicates that the tubular section 41 is axially displaceable relative to the sheath housing 43 within the receiving passage 46, or in other words, that the sheath housing 43 is displaceable relative to the tubular section 41.

[0072] The sheath shown here can be used, for example, as an introducer sheath (first sheath).

[0073] To insert a functional element, such as a pump, into the first sheath, tubular section 41 is generally withdrawn distally far enough from sheath housing 43 so that tubular section 41 terminates approximately at the height of first stop member 48, or is positioned during manufacture of the first sheath and clamped in place, for example, by operating pressure screw 45. The second sheath, including the containment pump described above, is then pushed forward to this point to transfer the pump from the second sheath into the first sheath.

[0074] The first clamping device includes a first pressure screw 45, a first clamping ring 50 made of an elastomeric material, and a first stop member 48 as a fastening means. A sliding layer or rotary seal ring 69 may be provided between the clamping ring 50 and the pressure screw 45.

[0075] The pressure screw is threadedly connected to the external threads of the distal end 44 of the sheath housing 43 at the overlap region. Therefore, manual rotation of the pressure screw 45 causes the pressure screw to move axially, resulting in axial compression or expansion of the clamping ring 50. In the case of axial compression, the clamping ring 50 encounters resistance from the first stop member 48 on the proximal side, so that the clamping ring 50 tends to clamp the tubular section 41 by expanding outward while maintaining its volume radially inward.

[0076] In this way, the tubular section 41 is axially fixed relative to the sheath housing 43. This fixation can be easily released by releasing the pressure screw 45, so that the tubular section 41 can be displaced axially by a short distance inside the sheath housing 43. For this reason, in the relaxed state the clamping ring can have an inner diameter equal to or larger than the diameter of the first sheath.

[0077] Thus, if tubular section 41 is first advanced as deep into the patient's body as possible so that the pump, protected by the sheath, can be inserted to a deployment site, e.g., a ventricle of the heart, then once the pump has been delivered, tubular section 41 is withdrawn, and the entire sheath protrudes a relatively long distance from the patient's body. Then, clamping devices 48, 45, and 50 are released, and sheath housing 43 can be advanced with tubular section 41 near the patient's body. At this step, tubular section 41 extends all the way to sheath housing 43, optionally protruding proximally from the housing. Using means described in more detail below, tubular section 41 can be partially removed to remove excess length.

[0078] To create a good seal, a so-called compound hemostatic valve, consisting of a dome valve 51 and a valve plate 52, is provided inside the sheath housing 43. The dome valve 51 is optimized to create a tight seal around the string-shaped element, e.g., the tubular section or the catheter, while the valve plate closes the sheath housing 43 when neither the tubular section 41 nor the shaft catheter extends into the receiving passage 46 at the sheath housing 43.

[0079] The proximal end 53 of the sheath housing 43 is provided with an additional pressure screw 54, which functions in principle similarly to the first pressure screw 45 and which, via a clamping pad 55, influences the compression of a second clamping ring 56 against a second mechanical stop 57. In this way, the catheter, or an inserted auxiliary sheath, can be clamped to the introducer sheath. It should be mentioned here that, as a unique feature, the second clamping ring 56 extends in the form of a cone at its distal end, which is advantageous for radial inward deformation when axial pressure is applied by the pressure screw 54. The second stop 57 is suitably designed as an inverse cone shape. However, clamping rings 56 that are non-conical or instead have a rectangular or round cross section can likewise be used here.

[0080] 10 shows a schematic illustration of a flushing device 58 for flushing the flushing chamber 47 inside the sheath housing with a fluid that prevents bacteria from entering the patient's body through the primary sheath. This flushing is particularly effective when the tubular section 41 terminates in the flushing chamber 47 or its distal end so that the flushing fluid reaches both the exterior and interior of the tubular section 41.

[0081] FIG. 11 illustrates by way of example the construction and mode of functioning of a cutting device according to the invention.

[0082] If predetermined breaking points are not provided, pre-cut or otherwise prepared, for example by a predetermined molecular structure or by a local weakening of the wall thickness of the tubular section 21, they can be suitably introduced by a cutting device during use of the first sheath. In Fig. 11, cutting devices with blades 59, 60 are provided in the region of the cleaning chamber 47 of the sheath housing 43, which blades cut the housing circumferentially, for example, when the sheath housing is rotated relative to the tubular section. Cutting can also be performed axially.

[0083] For this purpose, the blades 59, 60 may be arranged to make longitudinal cuts when the tubular section 41 is moved axially as indicated by the arrow 61. It is also possible to provide one blade for circumferential cutting and one blade for longitudinal cutting.

[0084] 11 further shows that blades 59, 60 are moved radially into tubular section 41 by operating the blade from outside sheath housing 43. At this point, radially extending guides for one or more blade holders, corresponding seals, and spring mounts are provided to prevent bacteria from entering the blade displacement mechanism, and in the unoperated state, the blade is positioned at a radial distance from tubular section 41. Once the first sheath has been used, manual pressure can be applied to the blade to cut off a portion of tubular section 41 that is no longer needed. A stop, not shown, prevents the cutting depth from exceeding a critical level, thereby damaging the catheter that may be positioned inside the sheath.

[0085] The illustrated blade also forms the cutting device for the second sheath.

[0086] 12 illustrates the advantageous use of a second clamping device at the proximal end of the sheath housing 43 when the tubular section 41 is shortened and the shaft catheter 61 exits the proximal end of the tubular section 41 and the sheath housing 43, connecting to a coupling device (not shown) for the pump's drive shaft. The shaft catheter is sealed within the aforementioned dome seal 51, and the clamping device, including elements of the second pressure screw 54 and the second clamping ring 56, axially compressed against a second stop 57 by a clamping pad 55, expands radially inward sufficiently to clamp the shaft catheter 61, which has an outer diameter substantially smaller than the tubular section 41, or in particular, the second sheath that also seals the catheter. However, this clamping does not prevent rotation of the shaft, which is rotatable within. In this way, both the tubular section 41 and the shaft catheter 61 projecting from it can be secured inside the sheath housing 43.

[0087] The second clamping device is similarly suitable for fixing the second sheath with the second clamping ring 56 during insertion of the second sheath into the sheath housing 43 so that the second sheath is properly fixed relative to the sheath housing 43, particularly relative to the tubular section 41, and the shaft catheter 61 is pushed therethrough.

[0088] The first and second clamping rings 50, 56 are made of elastomer, such as rubber or silicone elastomer, and are therefore completely flexible but deformable in volume while remaining uncompressible. However, flexible foams that are partially compressible in volume can also be used in this location. Instead of the clamping ring 56, radially displaceable spring clips are provided to create the clamping connection, as shown in Figures 13g, 13h, and 13i, and will be described in more detail below. Corresponding spring clips can be provided in addition to or instead of the clamping rings. The spring clips can be provided in the area of ​​dotted line 70 in Figure 12. However, since the area of ​​dotted line 70' is proximal to the seal 51, it is advantageous to also provide the spring clip in the area of ​​dotted line 70', so that the sliding mechanism of the spring clips does not need to apply particularly high stresses to the seal.

[0089] 13a to 13i show sheath clamping and / or fixation devices that may be used alone or in combination on introducer sheaths and / or auxiliary sheaths.

[0090] 13a shows a schematic view of a clamping ring 62, for example made of plastic or metal, which is in particular slotted and therefore radially compressible. The slotted clamping ring 62 has a conical outer contour against which the conical contour of the clamping pad 63 is pressed in order to radially compress the clamping ring as soon as an axial compressive force is applied to the clamping pad 63 in the direction of arrow 65, for example by the pressure screw mentioned above. The slotted clamping ring 62 is axially fixed by a stop member 64.

[0091] 13b shows an adapter member 71 inside the sheath housing 43 having a through passage 72 with continuous flutes and beads 73 on its outer cylindrical surface that engage with flutes and beads 74 on a mating adapter member 75 of a clamped element 76. The mating adapter member 75 is inserted into the adapter member 71 and snaps therein by virtue of its flexibility, holding it in place and advantageously forming a seal. A stop member 77 prevents the element 76 from being inserted too deeply, so that the snap connection can be detected tactilely.

[0092] Figure 13c shows an arrangement similar to that of Figure 13b, in which the adapter member 71' and the mating adapter member 75' each have threads rather than concentric continuous flutes and beads. The mating adapter member 75' is moved into the adapter member 71' by rotating it, although it is also conceivable to insert the adapter axially over the threads. Visual markings 78 are provided on the clamping element 76 to allow identification of the target position. However, geometric markings may be provided so that the target position can be detected tactilely or acoustically, or a mechanism may be provided to operate electrical contacts to emit a signal when the target position is reached or left.

[0093] 13d shows a cone 79 on the clamping element 76, which fits into a conical recess 80 in the adapter member 71', forming a seal. The cone 79 has one or more circumferential pins 81, which are guided in gates 82 on the inner circumferential surface of the recess 80, and serve to form a bayonet-type sheath. Conversely, the pins may be provided on the outer cone and the gates on the inner cone. While maintaining a corresponding reference in the connection between the sealing cone and the sheath, a so-called Luer sheath may also be formed. Instead of a bayonet sheath, a threaded connection may also be provided with the cone system.

[0094] FIG. 13e shows a rotated side view of a cone 79 containing two pins 81.

[0095] 13f shows a cone system having a cone 79' and a threaded nut 83 surrounding the cone. The threaded nut 83 can be threadedly coupled to the threads of a pipe socket 84 that is connected to an adapter member 85. The adapter member 85 is fixedly assembled to the sheath housing 43 of the introducer sheath and has an inner cone. The threaded nut 83 can also be embodied as a cap nut that is freely rotatable relative to the cone 79'.

[0096] FIG. 13g shows a sheath housing with a radially displaceable spring clip that can be operated by a push button 87. A stop 88 is provided to stop the push button 87 at the desired position. Additionally, optically detectable markings can be provided on the spring clip. As the spring clip 86 is moved into the sheath housing, it enters an opposing guide 89. Prior to this, the spring clip elastically expands upon impact with the element to be clamped 76. For this purpose, the spring clip has an entrance opening 90, as shown in FIG. 13i. As insertion continues, a holding area 91 rests around the element to be clamped. As is clear from FIG. 13h, this element can have a continuous groove or flute 92 or a collar 93 with such flutes 92. In this variant, the functions of clamping and sealing the element to be clamped are separate.

[0097] Contrary to the described method of function, clamping may also be achieved by advancing the spring clip all the way into the sheath housing 43 and then axially inserting the element to be clamped, e.g., a catheter or a second sheath. In this case, the conical guide bevel 94 causes the collar 93 inserted with the element to be clamped by the spring clip 86, where it is held in place.

[0098] In principle, the clamped element / second sheath is also held to the first sheath by flexible, self-covering vanes, fins, or teeth that either cover the element as it is being withdrawn from the sheath or make this withdrawal significantly more difficult. Such vanes are shown diagrammatically on the left side of Figure 13d and identified with reference numeral 95.

[0099] 14 shows an introducer sheath sheath housing 43' having a receiving passageway 46 therein for a sheath and / or catheter. At its distal end 44, the sheath housing 43' has a tubular section 41 fastened to the end, which may be, for example, bonded, molded, or otherwise fastened to the opening in the sheath housing. The tubular section 41 is inserted into the opening in the sheath housing 43' up to a mechanical stop 63.

[0100] The secondary sheath 20" (auxiliary sheath) is inserted from the proximal end 53 of the sheath housing 43' into the receiving passage 46 far enough to terminate distally in the mechanical stop 63. In one embodiment, the system may be designed so that the secondary sheath 20" terminates just at the tubular section 41. A functional element, for example in the form of a pump with a hollow catheter, is housed in the secondary sheath 20"' and will not be described further.

[0101] To transfer the catheter containing the pump from the second sheath 20"' into the tubular section 41 of the first sheath 43', 41, the two sheaths are coaxially aligned with one another in the receiving channel 46, and the second sheath 20"' is fixed in place by a clamping device. The clamping device has a flexible clamping ring 56' which is embodied at its distal end as a cone and which presses against a mechanical stop 57'. For this purpose, an axial pressure is applied to the clamping ring 56' by means of a pressure screw 54' which has an external thread 64. For this purpose, the pressure screw 54' is threadably coupled to the opening of the tubular section of the sheath housing 43' and therefore moves axially in the direction of arrow 65.

[0102] To reduce friction between the rotary pressure screw 54' and the clamping ring 56', a rotary seal ring 69, made for example of PTFE or other plastic with good sliding properties, is advantageously provided.

[0103] The clamping ring 56' is made of, for example, an elastomer and radially expands under axial pressure to clamp the string-shaped element placed in the receiving passage 46. In the clamping area, for example, to improve the clamping action, the element to be clamped may have one or more continuous beads, lands, grooves, flutes, or edges. For this purpose, the element may be provided with a collar. The second sheath 20"' has a wall thickness of between 0.3 and 0.7 mm and is made of a material stable enough to withstand radial pressure so that the second sheath can be clamped without simultaneously clamping the catheter extending therethrough. In this way, the catheter can be easily pushed out of the proximal end of the second sheath 20"' and into the tubular section 41. The second sheath 20"' is sealed in the washing chamber 47 by plate and dome combination seals 51, 52.

[0104] Once the functional element, e.g., a pump, together with the catheter, has been transferred from the secondary sheath 20"' into the tubular section 41, the secondary sheath is peeled away and removed using the manual tabs 67, 68. For this purpose, the secondary sheath has an axial weakened area or notch or a corresponding predetermined molecular structure so that it can be broken longitudinally to its distal end and removed accordingly. To break the sheath, it may be convenient to release the clamping devices 54', 56', 57'.

[0105] When the second sheath is removed or partially removed, the additional radial compression of the clamping ring 56' results in a tight clamping arrangement of the clamping devices 54', 56', 57' sufficient to clamp a catheter having a smaller diameter within the receiving space 46. The catheter, and therefore the implanted pump, is thus axially secured to the distal end of the catheter relative to the first sheath and, therefore, to the patient's body.

[0106] However, a second sheath (auxiliary sheath) may be embodied to remain in the introducer sheath, in which case proper sealing and cleaning performance should also be ensured, as will be specified in more detail below.

[0107] For each of the different end positions of the pressure screw corresponding to the different clamped diameters, noticeable stops are provided by features not shown in the sheath housing, so that when the respective clamping position is reached, the user will notice a clear increase in rotational resistance to manipulating the screw.

[0108] Following an initial phase in which the assembly is mechanically stabilized and warmed to the patient's body temperature, the clamping device is released, the catheter is readjusted, and then refastened. Wherever two cylindrical elements are inserted into one another to form a seal, conical seals having a cone angle of several degrees are advantageously used, as is well known in the medical field.

[0109] In the described sheath embodiments, for example, an implantable heart pump can be transferred from a second sheath in a ready state after an initial examination to a first sheath leading to the patient's body without any problems and with low complexity and high reliability.

[0110] FIG. 15 shows an introducer sheath 101 on the right side of the figure and an auxiliary sheath 104 on the left side, with the tubular portion 112 of the auxiliary sheath inserted into the introducer sheath 101 and clamped in place.

[0111] The introducer sheath 101, as well as the auxiliary sheath 104, substantially correspond to the sheaths shown in FIG. 14 and described herein.

[0112] The overall sheath assembly shown in Figure 15 includes an introducer sheath and an auxiliary sheath and is suitable for inserting a string-shaped element / catheter 105 from the auxiliary sheath 104 into the introducer sheath 101 and from the introducer sheath into the patient's body.

[0113] The introducer sheath 101 further comprises a tubular section 41a at its distal end 102, which is fixed to form a seal with the proximal section 103 forming the sheath housing 114. The tubular section 112 at the distal end of the auxiliary sheath 104 is inserted into the introducer sheath 101 and pushed in until it reaches the front stop 63 of the introducer sheath tubular section. The stop 63 simultaneously forms an axial stop for the auxiliary sheath tubular section 112 and for the proximal end of the introducer sheath tubular section 41a, and the tubular sections 112, 41a may have the same inner diameter as the flange-type stop 63. The stop 63 is formed in the housing wall of the sheath housing. The introducer sheath comprises a first fastening means 108, which may be similar in design to the second fastening means 107 of the auxiliary sheath 104 and which has been described in detail with reference to FIG. 14 as a clamping device. In principle, however, the first and second fastening means may comprise each of the fastening means types shown by way of example in Figures 13a to 13j.

[0114] In order to keep the transition area between the auxiliary sheath and the tubular part of the introducer sheath in the interior 110 of the housing 114 of the introducer sheath sterile and to this end to clean this area, a cleaning device 108 is provided with a corresponding cleaning tube and an opening in the wall of the housing 114. The cleaning device is connected to a cleaning medium source 120, which includes, for example, a pump 121 and a container 122. The auxiliary sheath 104 likewise has a cleaning device 109 which includes a cleaning tube and an opening in the wall of the housing 113. Via this cleaning device 109, the interior 111 of the housing of the auxiliary sheath and therefore the transition area from the catheter 105 to the tubular part 112 of the auxiliary sheath is cleaned and kept sterile.

[0115] The first cleaning device 108 is connected to, for example, the second cleaning device 109 via a cleaning medium supply 120. A pump 121 can thus be provided to deliver cleaning medium to both the first cleaning device 108 and the second cleaning device 109 and to deliver this medium to the interior chambers of the housings 113, 114.

[0116] 16 shows a variant in which a cleaning medium source 120 supplies cleaning medium to the interior 110 of the housing 114 of the introducer sheath 101 via a first cleaning device 108. The tubular portion 112 of the auxiliary sheath, fixed inside the introducer sheath, has at least one external opening 119, e.g., external perforations, consisting of multiple openings, in the internal chamber 110 through which the cleaning medium enters the tubular portion 112 and flows axially into the housing interior 111 of the housing 113. Thus, the cleaning medium can be actively transferred from the cleaning medium source 120 through the introducer sheath 101 to the auxiliary sheath 104. In such a case, a structural device of the second cleaning device 109 may function to drain the auxiliary sheath, e.g., to expel the cleaning fluid therein, in order to collect the cleaning fluid in a collection tank 123. In this case, the interior of the tubular portion 112 of the auxiliary sheath forms part of an auxiliary cleaning passage 115′ connecting the two sheaths. In the variant shown in FIG. 15, an auxiliary flushing passage 115 is provided by the inlet pipes of the flushing devices 108, 109 and / or their connections.

[0117] The outer opening / recess 119 of the tubular portion 112 of the auxiliary sheath may be introduced into the portion 112 only after the catheter has been inserted into the patient's body, for example. For example, a cutting assembly as shown in Figure 11 may be used for this purpose.

[0118] Finally, Figure 17 shows a design in which the sheath housing 114 of the introducer sheath is securely connected to the sheath housing 113 of the auxiliary sheath 104. The two sheath housings are cylindrical or somewhat conical subregions that are securely inserted one inside the other. A threaded or bayonet connection may also be provided.

[0119] For example, in the illustrated embodiment, a circumferential groove 116 is provided, formed by a circumferential groove on one side in the auxiliary sheath housing 113 and on the other side in the introducer sheath housing 114. However, it is sufficient to provide a circumferential groove on only one of the housings. The circumferential groove or grooves are each connected via a channel-like recess 117, 118, which extends through the wall of the respective housing 114, 113 into the first cleaning device 108 and / or the interior of the respective sheath housing 114, 113. As a result, in the illustrated variant, the interior of the housing 114 and the interior of the housing 113 can be cleaned via the first cleaning device 108. In this case, a second cleaning device 109 is used for drainage and for ejecting cleaning fluid, as shown in FIG. 16. However, cleaning of both housings can also be performed conversely by the second cleaning device. Due to the provided circumferential groove 116, it is not necessary to glue the two sheath housings in a precise angular position when connecting them, but rather it is only necessary that the axial position of the two sheath housings 101, 104 is maintained relative to one another, which can be ensured, for example, by a fixed stop on one of the two sheath housings.

[0120] Additionally, a spring-mounted sliding element on the inner circumferential side of housing 114, in each case in the region of the circumferential groove, and one such element on the outer side of housing 113, can serve to ensure that the corresponding circumferential groove and / or channel-like recess is covered before connection of the two housings. The sliding element is spring-loaded and retractable so that the circumferential groove or recess in question is not covered during joining of the two housings.

[0121] In the case of the configuration of FIG. 17, the channel-like recesses 117, 118 and / or the circumferential groove 116 form the auxiliary cleaning passage 115''.

[0122] In the variation described above, the auxiliary sheath 104 is permanently connected to the introducer sheath 101 and remains connected thereto while the two are washed together to ensure that bacteria are prevented from entering the patient's body in the area of ​​the sheath.

[0123] Figure 18 shows an embodiment of a sheath assembly in which a sterile tubing 130 is connected in a fluid-tight connection to an introducer sheath 101. In principle, this tubing could be flushed from the introducer sheath 101 or from an auxiliary sheath 104' (only partially and diagrammatically shown in Figure 18).

[0124] The sterile tubing 130 is itself fluid-tight and embodied as a corrugated tube. It is connected to the housing of the introducer sheath 114 and / or to the housing of the auxiliary sheath and / or to the catheter grip by a flange connection or glue connection 131, or generally by one of the connection types shown in Figures 13a to 13i, and at least partially surrounds the auxiliary sheath partially inserted into the introducer sheath. The sterile tubing can also be clamped immediately adjacent to the catheter shaft.

[0125] Once the catheter has been inserted into the patient's body, the entire secondary sheath may be housed inside the sterile tube 130. The proximal end member 132 has a through passage for the catheter, which feeds through the passage that forms the seal.

[0126] Following the insertion process, the sterile tubing is compressed axially and end member 132 may be connected, for example, to flange 131. The secondary sheath is peeled away as a peel-away sheath and withdrawn from the introducer sheath into the sterile tubing, where it remains. The introducer sheath may then be sealed to the sterile tubing.

[0127] 19a shows an axial cross-sectional view of the sheath assembly, with the string-shaped element / catheter 105 extending into the tubular portion of the auxiliary sheath 21, which is placed inside the tubular portion of the introducer sheath 41a. The string-shaped element / catheter 105, shown in this example as a hollow catheter, has an outer diameter d1. The tubular portion of the auxiliary sheath 21 has an outer diameter d2 and an inner diameter corresponding to the outer diameter d1 of the string-shaped element / catheter 105. The tubular portion of the introducer sheath 41a has an inner diameter corresponding to the outer diameter d2 of the tubular portion of the auxiliary sheath, and an outer diameter d 3a Generally, the wall thickness of the component cannot be reduced randomly based on material properties.

[0128] In this type of sheath assembly, the outer diameter of the entire system, d 3a is relatively large due to the configuration of the tubular sections of the auxiliary sheath and introducer sheath, one around the other, and obviously results in a correspondingly high degree of trauma and risk of bleeding at the point of passing through the patient's skin.

[0129] 19b shows an axial cross-section of the sheath assembly in which the string-shaped element / catheter 105 extends into the tubular portion of the secondary sheath 21, which is located axially proximally to the tubular section of the introducer sheath, and is therefore not shown in this figure. It is clear that the outer diameter of the system in this region corresponds to the outer diameter d2 of the tubular portion of the secondary sheath.

[0130] Figure 19c shows another axial cross-sectional view of the sheath assembly of Figure 19b, in which the string-shaped element / catheter 105 is located distal to the cross-sectional view of Figure 19b in a plane extending through the tubular section of the introducer sheath 41a. The tubular section of the secondary sheath does not lie on this plane. The absence of a secondary sheath in this section reduces the outer diameter d of the tubular section of the introducer sheath 41a. 3b is designed to be substantially small, for example it corresponds to the outer diameter of the tubular section of the auxiliary sheath 21 or is even smaller than this.

[0131] In such a sheath assembly, the outer diameter of the entire system, d 3b is substantially smaller due to the positioning of the tubular sections of the auxiliary sheath and introducer sheath, one axially forward of the other, resulting in a corresponding reduction in trauma and risk of bleeding at the point of penetration through the patient's skin. The embodiments described below are also included in the specific examples of the present invention. Aspect 1: A sheath assembly for inserting a catheter that is a string-shaped element (32, 105) into a patient's body, comprising an introducer sheath (101) having a distal end (102) provided for insertion into the patient's body and a proximal end (103) that protrudes from the patient's body during insertion of the distal end of the assembly into the patient's body, and an auxiliary sheath (104) for insertion into the introducer sheath (101) together with the string-shaped element / catheter (32, 105), and comprising first fastening means (106) for detachably fastening the auxiliary sheath to the introducer sheath and second fastening means (107) for detachably fastening the string-shaped element to the auxiliary sheath, wherein the introducer sheath (101) comprises a first sheath housing (13, 114), a first receiving passage for the string-shaped element (32, 105), and a distal sheath terminating in the first sheath housing. The auxiliary sheath (104) has a first sheath inner chamber (110) having a tubular section (11, 11a) and a first cleaning device (108) for cleaning the sheath inner chamber (110), the auxiliary sheath (104) has a second sheath inner chamber (111) having a second receiving passage for the string-shaped element (32, 105), a tubular distal portion (112), and a second cleaning device (109) for the second sheath inner chamber (111), and the first sheath housing (13, 114) a means (63) for positioning the distal end of the tubular distal portion (112) of the auxiliary sheath (104) proximally forward of the proximal end of the tubular section (11, 41 a) in the first sheath housing (13, 114), and the second cleaning device (109) is connected to the first cleaning device (108) to enable exchange of cleaning fluid between the first cleaning device (108) and the second cleaning device (109). <Aspect 2> A sheath assembly as described in Aspect 1, characterized in that the auxiliary sheath (104) has a tubular distal portion (112) and a sheath housing (113), the tubular distal portion (112) is inserted into the introducer sheath (101), and the auxiliary sheath (104) is detachably connected to the introducer sheath (101). <Aspect 3> A sheath assembly as described in Aspect 1, characterized in that the auxiliary sheath (104) has a tubular distal portion (112) and a sheath housing (113), and the sheath housing (113) of the auxiliary sheath is detachably connected to the sheath housing (114) of the introducer sheath (101). <Aspect 4> A sheath assembly described in any of Aspects 1 to 3, characterized in that the connection between the auxiliary sheath (104) and the introducer sheath (101) is embodied as a detachable clamp connection including a pressure-fit connection or a friction connection, as a double cone connection, a threaded connection, a bayonet connection, a press-fit connection, or as other detachable engagement connection. <Aspect 5> A sheath assembly described in Aspect 2 or 3, characterized in that the inner chamber of the sheath housing (113) of the auxiliary sheath is directly connected to the first cleaning device (108) by an auxiliary cleaning passage (115, 115', 115''). <Aspect 6> A sheath assembly as described in Aspect 5, characterized in that the auxiliary cleaning passage (115, 115', 115") extends to a conduit in the form of a hose or tube attached to the outer periphery of the housing of the auxiliary sheath (104). <Aspect 7> A sheath assembly as described in Aspect 5, characterized in that the auxiliary cleaning passage (115, 115', 115") extends directly from the sheath housing (114) of the introducer sheath (101) to the inside of the tubular distal portion (112) of the auxiliary sheath (14) through an outer surface opening (119) of the tubular distal portion (112) of the auxiliary sheath. <Aspect 8> A sheath assembly as described in Aspect 5, characterized in that in the case of a direct connection between the sheath housing (113) of the auxiliary sheath and the sheath housing (114) of the introducer sheath, the auxiliary cleaning passage (115, 115', 115") extends inside the connection area through a region of the wall of the sheath housing (113) of the auxiliary sheath that is positioned inside the introducer sheath (101). <Aspect 9> A sheath assembly as described in Aspect 8, characterized in that the introducer sheath (101) and the auxiliary sheath (104) abut each other as connecting mates in an annular region, a circumferentially extending annular or arcuate circumferential groove (116) is provided in at least one of the two connecting mates in the annular region, and passage-like recesses (117, 118) are provided in both the sheath housing (114) of the introducer sheath and the sheath housing (113) of the auxiliary sheath, connecting the inner chamber of the sheath to the circumferential groove (116) in a connected state. <Aspect 10> A sheath assembly described in any of Aspects 1 to 9, characterized in that a sterile tube (130) is connected to the introducer sheath (101) in a fluid-tight connection, the tube forming a proximal extension of the introducer sheath (101) and surrounding at least a portion of the auxiliary sheath (104), and the sterile tube is connected to the auxiliary sheath (104) in a fluid-tight connection. <Embodiment 11> A sheath assembly according to embodiment 10, wherein the sterile tube (130) is attached to the end face of the introducer sheath (101). <Aspect 12> A sheath assembly as described in Aspect 10, wherein the sterile tube (130) terminates in a liquid-tight manner at the housing of the auxiliary sheath (104). <Aspect 13> A sheath assembly as described in Aspect 10, wherein the sterile tube (130) is axially compressible and, once the string-shaped element (32, 105) is inserted into the introducer sheath (101), the auxiliary sheath (104) and the tubular distal portion (112) of the auxiliary sheath are pushed into the introducer sheath and placed on the introducer sheath. <Aspect 14> A sheath assembly described in any of Aspects 1 to 13, characterized in that the inner diameter of the tubular distal portion (112) of the auxiliary sheath is larger than the inner diameter of the tubular section (11, 41a) of the introducer sheath, or each of the tubular distal portion (112) and the tubular section (11, 41a) has the same diameter as the means (63) for positioning the distal end of the tubular distal portion (112) in the first sheath housing (114). <Aspect 15> A sheath assembly as described in Aspect 1, characterized in that the outer diameter of the tubular section (11, 41a) of the introducer sheath (101) is equal to or smaller than the outer diameter of the tubular distal portion (112) of the auxiliary sheath. <Aspect 16> A system comprising a string-shaped element and a sheath assembly for inserting the string-shaped element into a patient's body, as described in at least one of aspects 1 to 15, wherein the string-shaped element is a pump.

Claims

1. 1. A sheath assembly for inserting a catheter into a patient's body, comprising: Equipped with an introducer sheath and an auxiliary sheath, the introducer sheath comprising a first tubular portion and an introducer sheath housing; the first tubular portion has a proximal end and a distal end, the distal end configured to be inserted into the body of the patient, and the proximal end protruding from the body of the patient upon insertion of the distal end; the introducer sheath housing is coupled to the proximal end of the first tubular portion; the auxiliary sheath includes a second tubular portion and an auxiliary sheath housing; the second tubular portion has a proximal end and a distal end, the distal end configured to be inserted into the introducer sheath housing; the auxiliary sheath housing is coupled to the proximal end of the second tubular portion; when the distal end of the second tubular portion approaches the proximal end of the first tubular portion, the distal end of the second tubular portion is inserted into the introducer sheath housing and clamped against an inner wall of the introducer sheath housing, thereby coupling only the distal end of the second tubular portion to the introducer sheath within the auxiliary sheath.

2. 10. The sheath assembly of claim 1, the introducer sheath housing further includes a mechanical stop on the inner wall having a first contact surface and a second contact surface; the first contact surface is configured to prevent the distal end of the second tubular portion from moving distally beyond the mechanical stop; the second contact surface is configured to prevent the proximal end of the first tubular portion from moving proximally beyond the mechanical stop; the second tubular portion is further characterized in that the distal end of the second tubular portion is removably clamped to the introducer sheath housing when the distal end of the second tubular portion contacts the first contact surface of the mechanical stop and the proximal end of the first tubular portion contacts the second contact surface of the mechanical stop.

3. 10. The sheath assembly of claim 1, the first tubular portion has an inner diameter and an outer diameter; The sheath assembly, wherein the second tubular portion has an inner diameter and an outer diameter.

4. 4. The sheath assembly of claim 3, The sheath assembly, wherein the auxiliary sheath and the introducer sheath are configured to allow the catheter to extend through the second tubular portion and the first tubular portion.

5. 5. The sheath assembly of claim 4, The sheath assembly, wherein the outer diameter of the second tubular portion is equal to the outer diameter of the first tubular portion.

6. 5. The sheath assembly of claim 4, A sheath assembly, wherein the outer diameter of the second tubular portion is greater than the outer diameter of the first tubular portion.

7. 4. The sheath assembly of claim 3, The sheath assembly, wherein the inner diameter of the first tubular portion is equal to the outer diameter of the catheter.

8. 4. The sheath assembly of claim 3, The sheath assembly, wherein the inner diameter of the second tubular portion is equal to the outer diameter of the catheter.

9. 10. The sheath assembly of claim 1, A sheath assembly characterized in that the auxiliary sheath is configured to removably fix the catheter to the auxiliary sheath using a deformable ring or collar, the ring or collar being configured to clamp a portion of the catheter when it is deformed.

10. 10. The sheath assembly of claim 1, 10. A sheath assembly comprising: an auxiliary sheath configured to removably secure the catheter to the auxiliary sheath using a snap-fit ​​adapter, the snap-fit ​​adapter configured to form a snap connection with a portion of the auxiliary sheath.

11. 10. The sheath assembly of claim 1, A sheath assembly, characterized in that the auxiliary sheath is configured to removably secure the catheter to the auxiliary sheath using a threaded adapter configured to threadably couple with a portion of the auxiliary sheath.

12. 10. The sheath assembly of claim 1, A sheath assembly, characterized in that the auxiliary sheath is configured to removably secure the catheter to the auxiliary sheath using a spring clip configured to clamp a portion of the catheter.

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