Balloon-fixed flexible needles and catheters for biopsy

Abstract

The present disclosure provides a catheter for insertion into a subject and guidance to a target organ, the catheter comprising a first elongated tube and a second elongated tube, the first elongated tube having a first lumen with a first proximal end and a first distal end, the second elongated tube having a second lumen with a C-shaped cross-section forming a channel with a second proximal end and a second distal end, the second elongated tube sharing a common wall with the first elongated tube.

Description

Technical Field

[0001] The present disclosure relates to a biopsy device, and more particularly, to a biopsy device for obtaining a biopsy sample of a target organ. In particular, the present disclosure relates to a biopsy device comprising a flexible surgical instrument that can be inserted through a catheter into a peripheral vascular access site for performing a soft tissue biopsy.

Background Art

[0002] Current methods for performing a liver biopsy may involve a significant risk of serious complications, which often cause patients to choose to delay the biopsy procedure, subsequently delaying the diagnosis and treatment intervention for liver dysfunction. Such methods may include open surgery, percutaneous liver biopsy (PLB), and transjugular liver biopsy (TJLB).

[0003] Open surgical liver biopsy directly removes liver tissue during a laparoscopic or surgical procedure. Open surgical liver biopsy in current treatments can be utilized when a surgical procedure is already being performed.

[0004] Percutaneous liver biopsy (PLB) may involve extracting a core sample of liver tissue using a biopsy needle inserted through the abdominal wall. In PLB, a hole is made in the liver capsule and a high penetration depth is required to reach its parenchyma. This procedure can often provide a good biopsy sample, but this procedure is invasive and painful and may be associated with a significant risk of serious complications including a significant risk of death (1 in 250). If the first biopsy fails and additional biopsy samples are required, additional needle punctures may be necessary, increasing the risk of complications even further. Therefore, PLB patients may be placed under observation for several hours after the procedure to ensure no intraperitoneal bleeding due to puncture of the liver capsule or blood vessels.

[0005] TJLB involves accessing the liver by inserting a rigid metal catheter into the right or left jugular vein and guiding it through the right ventricle of the heart into the hepatic veins of the liver. A large-bore needle pointed downwards from the catheter is used to remove liver tissue from the center. A large number of samples are often required for satisfactory analysis.

[0006] Similar to PLB, TJLB avoids the risk of undetected bleeding into the peritoneum because any bleeding from the needle puncture returns to the hepatic vein. However, because TJLB involves guiding a rigid metal catheter through major organs and blood vessels, this procedure can lead to serious complications such as bleeding, arrhythmias, vascular perforation, pneumothorax, or death. While TJLB is sometimes considered safer than PLB, it carries the risk of new complications associated with the jugular vein access site.

[0007] Therefore, to reduce the risk of major complications associated with PLB and TJLB procedures, there is a need for transvenous biopsy devices that can be introduced into the patient's body via, for example, the ulnar / radial cephalic vein into the peripheral venous system of the arm, and that can be flexibly guided through the venous system to perform soft tissue biopsies on target organs such as the liver.

[0008] Patent Document 1, published by the applicant on May 31, 2019 (its disclosure is incorporated herein by reference), describes a balloon-fixed biopsy device. The disclosed balloon-fixed biopsy device had two elongated tubes with two lumens. However, while this was sufficient for most applications, several problems arose in that the two elongated tubes bent and twisted while guiding the vascular system. This twisting caused the effective inner diameter of the tubes to become elliptical (i.e., the same equivalent diameter), and constricted the biopsy needle or excessively hindered the advancement and ejection of the biopsy needle. Furthermore, the angle at which the needle entered the soft tissue was still not optimal.

[0009] Therefore, considering the current equipment used to obtain core specimens from soft tissue, it is desirable to provide an improved biopsy apparatus. [Prior art documents] [Patent Documents]

[0010] [Patent Document 1] International Publication No. 2019 / 103694A1 [Overview of the project]

[0011] According to embodiments of the present disclosure, a catheter is provided for insertion into a target and guidance to a target organ, the catheter comprising a first elongated tube and a second elongated tube, the first elongated tube having a first lumen with a first proximal end and a first distal end, the second elongated tube having a second lumen with a c-shaped cross-section forming a channel with a second proximal end and a second distal end, and the second elongated tube sharing a common wall with the first elongated tube.

[0012] According to some embodiments of the present disclosure, the first lumen is bean-shaped. Optionally, a common wall is located in a recess of the bean-shaped lumen of the first elongated tube. Optionally, the first lumen has a closed curved shape with at least one recess. Optionally, the common wall is located opposite the opening of the channel of the second elongated tube. Optionally, the common wall has a thinner thickness compared to the other walls of the catheter.

[0013] According to some embodiments, the catheter may further comprise an extension connected to a first distal end, the extension comprising a third proximal end and a third distal end, the third proximal end being connected to the first distal end of the first elongated tube. Optionally, the extension is a common wall extension.

[0014] According to some embodiments, the catheter may further comprise a first tool for insertion into a first lumen of a first elongated tube. Optionally, the catheter may further comprise a second tool for insertion into a channel of a second elongated tube. Optionally, the second tool is a balloon catheter with a distal tip for insertion into a channel of a second elongated tube, the section of the balloon catheter near the distal tip having a balloon that, when inserted into a blood vessel of the target organ and inflated, secures the extension within a blood vessel near the biopsy site of the target organ. Optionally, the first tool is a biopsy needle configured to penetrate into the tissue of the target organ at a predetermined angle between the central axis of the second tool and the extension, and to exit from the first distal end of the first lumen to obtain a biopsy sample of the target organ.

[0015] According to some embodiments, the extension further comprises a balloon wrap at a third distal end, the balloon wrap configured to receive the balloon of a balloon catheter. Optionally, the balloon wrap has a C-shaped cross-section. Optionally, the extension comprises a channel wall along its side. Optionally, the height of the channel wall decreases from the third proximal end to the third distal end.

[0016] According to some embodiments, the first proximal end of a first elongated tube and the second proximal end of a second elongated tube are coupled to a needle biopsy device. Optionally, the biopsy needle comprises a coring needle and a stylet needle. Optionally, the coring needle includes one or more spiral cuts extending longitudinally around and along the coring needle. Optionally, the one or more spiral cuts have a constant pitch, or the one or more spiral cuts have a variable pitch.

[0017] According to some embodiments, the stylet needle has a notch along its circumference and longitudinally along the stylet needle. Optionally, the notch is not square and is deeper than it is wide. Optionally, the base of the notch has one or more corner fillets. Optionally, the notch is opposite. Optionally, the notch is rotated 90 degrees axially.

[0018] According to some embodiments, the stylet needle is provided with a recess at the fourth distal end of the stylet needle. Optionally, the recess has a flat base, or the recess has a concave base. [Brief explanation of the drawing]

[0019] The features, aspects, and advantages of this disclosure will be better understood by referring to the following description and accompanying drawings.

[0020] [Figure 1A] The following schematic diagrams illustrate catheter body assemblies for delivering a tool to a target organ in a subject, according to several embodiments of the present disclosure. [Figure 1B] A schematic cross-section of a catheter according to several embodiments of this disclosure is shown. [Figure 2] A balloon catheter according to some embodiments of the present disclosure is schematically shown. [Figure 3A] A schematic top perspective view of an extension connected to the first distal end of the needle guide lumen at the distal exit of a catheter, according to some embodiments of the present disclosure. [Figure 3B] A schematic top perspective view of an extension connected to the first distal end of a needle guide lumen at the distal exit of a catheter equipped with a balloon catheter, according to some embodiments of the present disclosure. [Figure 3C] A schematic bottom perspective view of an extension connected to the first distal end of the needle guide lumen at the distal exit of a catheter, according to some embodiments of the present disclosure. [Figure 3D]A bottom perspective view of an extension connected to a first distal end of a needle guide lumen at a distal exit of a catheter with a balloon catheter, according to some embodiments of the present disclosure, is schematically shown. [Figure 4A] A distal end of a biopsy needle in a closed configuration, according to some embodiments of the present disclosure, is schematically shown. [Figure 4B] A distal end of a biopsy needle in an open configuration, according to some embodiments of the present disclosure, is schematically shown. [Figure 5A] A side view of a core needle, according to some embodiments of the present disclosure, is schematically shown. [Figure 5B] A bottom view of a core needle, according to some embodiments of the present disclosure, is schematically shown. [Figure 5C] A cross-section of a core needle, according to some embodiments of the present disclosure, is schematically shown. [Figure 5D] A distal end of a core needle, according to some embodiments of the present disclosure, is schematically shown. [Figure 6A] A top view of a stylet needle, according to some embodiments of the present disclosure, is schematically shown. [Figure 6B] A side view of a stylet needle, according to some embodiments of the present disclosure, is schematically shown. [Figure 6C] A blade of a stylet needle, according to some embodiments of the present disclosure, is schematically shown. [Figure 6D] A notch of a stylet needle, according to some embodiments of the present disclosure, is schematically shown. [Figure 7A] A distal end of a catheter body assembly within a hepatic vein with an uninflated inflatable balloon, according to some embodiments of the present disclosure, is schematically shown. [Figure 7B] A distal end of a catheter body assembly within a hepatic vein of a liver, with an inflated inflatable balloon and a biopsy needle penetrating the liver, according to some embodiments of the present disclosure, is schematically shown.

[0021] With particular close reference to the drawings, it is emphasized that the details shown are illustrative and intended to illustrate the embodiments of the present disclosure. In this regard, the description accompanied by the drawings will make it clear to those skilled in the art how embodiments of the present disclosure may be carried out.

[0022] Identical, duplicate, equivalent, or similar structures, elements, or parts appearing in one or more drawings are generally given the same reference number, may optionally be given additional letters to distinguish similar entities or variations thereof, may not be given a repeating designation, and / or notation. References to previously presented elements are given without necessarily further citing the drawings or descriptions in which they appear.

[0023] The dimensions of the components and features shown in the drawings are selected for convenience or clarity and are not necessarily shown to scale or in actual perspective. For convenience or clarity, some elements or structures are not shown, or are shown only partially, and / or are shown in different perspectives or from different viewpoints. [Modes for carrying out the invention]

[0024] In the following detailed description, many specific details are provided to provide a complete understanding of the invention. However, those skilled in the art will understand that the invention can be carried out without these specific details. In other examples, well-known methods, procedures, components, modules, units and / or circuits are not described in detail so as not to obscure the invention.

[0025] Embodiments of the present invention are not limited in this respect, but the terms “plurality” and “a plurality” as used herein may include, for example, “multiple” or “two or more.” The terms “plurality” or “a plurality” may be used throughout this specification to describe two or more components, devices, elements, units, parameters, etc. Unless expressly otherwise, embodiments of the methods described herein are not restricted to any particular order or arrangement. In addition, embodiments of the methods described or elements of embodiments of the methods may occur or be performed at the same time, simultaneously or in parallel. Unless specifically otherwise stated, the use of the conjunction “or” as used herein should be understood as comprehensive (any or all of the options described).

[0026] Embodiments of this disclosure describe a core needle biopsy device for peripheral access (e.g., transcephalic venous access) that overcomes the problem of insufficient force transmission from the handle to the cutting cannula and stylet at the biopsy site. The core needle biopsy device further includes a safety mechanism that prevents premature ejection of the coring needle, as well as providing separate locking mechanisms for the cannula and biopsy needle.

[0027] According to some embodiments of this disclosure, Figure 1A schematically shows a catheter body assembly 100 for delivering a tool to a target organ in a subject. For illustrative purposes, the following description may refer to the organ as the liver, but it should be understood that the target organ may be any organ. In some embodiments, the catheter body assembly 100 is secured by a balloon. The catheter body assembly 100 comprises a catheter 116 and a ferrule 160. The catheter 116 may be formed from a medical polymer having a Shore D of 60 (plus or minus 10). According to some embodiments, the catheter 116 comprises a first elongated tube and a second elongated tube. The first elongated tube comprises a first tool guide lumen 104 having a first proximal end 150, a first distal end 145 and a first distal outlet 130, and the second elongated tube comprises a second tool lumen 110 having a second proximal end 105, a second distal end 146 and a second distal outlet 135. In some embodiments of this disclosure, the catheter 116 is designed to deliver a first tool 400 to a target organ in a subject. The catheter 116 is further designed to accommodate a second tool 200 (see Figures 2, 3B, 3D, 7A, and 7B) to be delivered to an organ in a subject. The catheter 116 may be used to deliver a variety of surgical and non-surgical tools, such as needles, balloons, clamps, suture materials, lighting devices, imaging devices, cutting and / or shearing devices. For illustrative purposes, the following description will show and describe the first tool 400 as a biopsy needle 400 (see Figures 4A, 4B, 7A, and 7B) and the second tool 200 as a balloon catheter 200 (see Figures 2, 3B, 3D, 7A, and 7B), but it should be understood that a variety of other tools can be used in conjunction with the catheter 16. Similarly, the first tool guide lumen 104 is shown and described as the needle guide lumen 104, and the second tool lumen 110 is shown and described as the balloon catheter lumen 110.

[0028] In some embodiments of this disclosure, the needle guide lumen 104 is configured as a bean-shaped lumen 106 adapted to guide the biopsy needle 400 from a first proximal end 150 of the needle guide lumen 104 to a first distal end 145 of the needle guide lumen 104 and exit through a first distal exit 130. In some embodiments, the balloon catheter lumen 110 has a C-shaped cross section with an opening 114 extending along the entire length of the balloon catheter lumen 110, effectively forming a channel 126. In other embodiments, the balloon catheter lumen 110 may be a sealed lumen. The channel 126 may be adapted to connect or receive a balloon catheter 200, and the balloon catheter 200 may be longitudinally aligned within the channel 126. Once connected, the balloon catheter 200 may be secured by application of adhesive, thermal shrinkage of the balloon catheter lumen 110, or selective local modification of the balloon catheter lumen 110. This further prevents the balloon catheter 200 from becoming dislodged during venous tracking and guidance, or when a rigid biopsy needle 400 is inserted.

[0029] In some embodiments of this disclosure, the bean-shaped lumen 106 of the needle guide lumen 104 and the C-shaped balloon catheter lumen 110 share a common wall 107. A cross-sectional section 108 in the catheter 116 schematically illustrates that the bean-shaped lumen 106 of the needle guide lumen 104 and the C-shaped balloon catheter lumen 110 share a common wall 107. In some embodiments of this disclosure, the cross-sectional wall thickness of the catheter 116 is constant. Preferably, the opening 114 of the balloon catheter lumen 110 is directly opposite the common wall 107 of the needle guide lumen 104 and the balloon catheter lumen 110, such that the cross-section of the catheter 116 has a single axis of cross-sectional symmetry.

[0030] In some embodiments of the present disclosure, the first distal end 145 of the needle guide lumen 104 may terminate at the first distal exit 130. The first distal end 145 may be connected to an extension 131 having a third proximal end 302 and a third distal end 304, the third proximal end 302 of which may be connected to the first distal end 145 of the needle guide lumen 104. The extension 131 may be an extension of a common wall 107. The extension 131 is adapted to guide the biopsy needle 400 as it exits the first distal end 145 of the needle guide lumen 104 through the first distal exit 130 and into the liver parenchyma at the biopsy site. The extension 131 also prevents the biopsy needle 400 from puncturing the inflatable balloon 220 of the balloon catheter 200 (see Figures 2, 3B, 3D, 7A, and 7B) when the inflatable balloon 220 is inserted and inflated. The structure of the extension 131 is described in further detail in relation to Figures 3A-3D.

[0031] In some embodiments of this disclosure, the first proximal end 150 of the needle guide lumen 104 and the second proximal end 105 of the balloon catheter lumen 110 can be connected to a ferrule 160. The ferrule 160 may incorporate a Tuohy-Borst adapter to allow insertion of a biopsy needle 400 or any surgical device. The ferrule 160 has a ring with a reduced diameter to accommodate a link that can snap into the ferrule 160 and rotate around the ring. This link can be rigidly attached to the needle biopsy device, and the catheter 116 can be fixed to the needle biopsy device. This connection ensures a fixed relationship between the biopsy device and the catheter 116 when the biopsy needle 400 is inserted into the target organ.

[0032] Figure 1B schematically shows a cross-section of a catheter 116 according to several embodiments of the present disclosure. The catheter 116 has a bean-shaped lumen 106 for the passage of a biopsy needle 400 and a channel 126 for connecting to or receiving a balloon catheter 200.

[0033] In some embodiments of the present disclosure, the bean-shaped lumen 106 has a closed curved shape with at least one recess. In some embodiments, the bean-shaped lumen 106 is shaped such that the upper and lower parts form a circle 120 with a diameter of 1 to 3 mm (9 to 20 French on the French catheter scale) along the outer circumference, while the curved shape is formed by a common wall 107, and the entire cross-section of the catheter 116 fits within an inscribed diameter of 3 to 6.7 mm (9 to 20 French on the French catheter scale). Those skilled in the art will understand that the relative diameter of the circle 120 of the bean-shaped lumen 106 and the overall diameter of the catheter 116 can be adjusted to fit various sizes of surgical instruments or balloon catheters. For example, to fit a 16G biopsy needle, the diameter of the circle 120 can be 1.95 mm and the overall diameter of the catheter 116 can be 4.67 mm. Preferably, there is a displacement of 0.236 mm along the x-axis between the center of circle 120 and the centroid of the entire cross-section of catheter 116. Preferably, the common wall 107 has a point of minimum wall thickness to locally concentrate the deformation. As described above, when catheter 116 guides through a bend in the vascular system, this local deformation minimizes the deformation of the bean-shaped lumen 106. This prevents the bean-shaped lumen 106 from collapsing inward when catheter 116 is bent along an axis parallel to the y-axis along a bending diameter of 90 mm, where this bending diameter is the sharpest bending diameter through which catheter 116 is expected to pass. Due to the bean-shaped contour of the bean-shaped lumen 106, catheter 116 can bend relatively easily along an axis parallel to the Y-axis compared to an axis parallel to the X-axis, and thus catheter 116 can be naturally directed from the arm entrance to the inferior vena cava to the loop to the liver. Thus, the user can obtain clear tactile feedback about the position of the extension 131 relative to the orientation of the liver.

[0034] In some embodiments of the present disclosure, the central region of the bean-shaped lumen 106 has a concave arc 124 on one side and a convex arc 122 on the other side, with both arcs diametrically opposed to each other. Preferably, the intersection of the circles 120 lies along the same plane as the midpoints of the concave arc 124 and the convex arc 122. Preferably, the central region of the bean-shaped lumen 106 has a width of 1 to 3 mm from the midpoint of the concave arc 124 to the midpoint of the convex arc 122, ideally 2.3 mm. Those skilled in the art will understand that this width can be sized to allow the biopsy needle 400 to move freely through the bean-shaped lumen 106.

[0035] In some embodiments of this disclosure, the balloon catheter lumen 110 has an overall diameter of 1 to 4 mm, ideally 2.47 mm. Preferably, the balloon catheter lumen 110 has an inner diameter of 0.5 to 2.5 mm, ideally 1.67 mm, forming a channel 126. Preferably, the distance from the centroid of the cross-section of the catheter 116 to the center of the inner diameter of the catheter guide 110 is 1.689 mm. Preferably, the balloon catheter lumen 110 has an opening 114 of 0.3 to 2.5 mm, ideally 1.19 mm. Those skilled in the art will understand that all dimensions of the balloon catheter lumen 110 can be sized to allow the balloon catheter 200 to move freely within the channel 126.

[0036] In some embodiments of this disclosure, the walls of the catheter 116 are thinner than the other walls of the catheter 116 and have a uniform thickness, except for a common wall 107 which is at least 50% of the thickness of the walls of the catheter 116. Preferably, the walls of the catheter 116 are 0.3 mm to 0.6 mm thick, ideally 0.4 mm. Preferably, the common wall 107 is 0.15 mm to 0.3 mm thick, ideally 0.3 mm thick. The common wall 107 is located directly opposite the opening 114 and lies on an axis of symmetry passing through the cross-section 108 of the catheter 116 (see Figure 1A).

[0037] Figure 2 is a schematic diagram of a balloon catheter 200 according to some embodiments of the present disclosure. The balloon catheter 200 comprises an inflatable balloon 220 having a tapered portion 221 connected to the balloon catheter 200. Preferably, the tapered portion 221 has an angle of 15 to 60 degrees, ideally 30 to 60 degrees. The inflatable balloon 220 is positioned at the distal end of the balloon catheter 200 and may be positioned at a predetermined distance "t" from the distal tip 225 of the balloon catheter 200. Preferably, the predetermined distance "t" is 1 to 10 mm, ideally 3 mm. Optionally, there may be one or more inflatable balloons 220.

[0038] In some embodiments of this disclosure, the inflatable balloon 220 may be manufactured in a semi-compliant structure having a length of 2–8 cm, ideally 4–6 cm. Preferably, when inflated, the inflatable balloon 220 may have a diameter of 5–15 mm, ideally 10 mm. Those skilled in the art will understand that the maximum diameter of the inflatable balloon 220 may be sized to 20% or less of the target vessel diameter. The fourth proximal end 235 of the balloon catheter 200 may be equipped with a hub 240 common to over-the-wire balloon catheters. The distance between the tip 225 of the balloon catheter 200 and the hub 240 may be a length "z". Preferably, the length "z" is 500–1100 mm, ideally 900 mm. The hub 240 may be equipped with an inflation port 245 and a guidewire inlet / outlet port 252. The inflatable balloon 220 may be inflated by air coupled to the inflation port 245. For example, any suitable air valve or stopper mechanism may be used to retain the air inside the inflatable balloon 220 in order to keep it inflated, or to open to deflate the inflatable balloon 220.

[0039] According to some embodiments of the present disclosure, Figures 3A–3D schematically show perspective views of an extension 131 connected to the first distal end 145 of the needle guide lumen 104 at the distal exit 130 of the catheter 116, with or without the balloon catheter 200 inserted. According to some embodiments of the present disclosure, Figure 3A schematically shows a top perspective view of an extension 131 connected to the first distal end 145 of a needle guide lumen 104 at the distal exit 130 of a catheter 116; Figure 3B schematically shows a top perspective view of an extension 131 connected to the first distal end 145 of a needle guide lumen 104 at the distal exit 130 of a catheter 116 equipped with a balloon catheter 200; Figure 3C schematically shows a bottom perspective view of an extension 131 connected to the first distal end 145 of a needle guide lumen 104 at the distal exit 130 of a catheter 116; and Figure 3D schematically shows a bottom perspective view of an extension 131 connected to the first distal end 145 of a needle guide lumen 104 at the distal exit 130 of a catheter 116 equipped with a balloon catheter 200.

[0040] In some embodiments of the present disclosure, the extension 131 has a length of 10 to 150 mm, ideally 70 mm, so as to extend along the entire length of the inflatable balloon 220. Preferably, the extension 131 has a channel wall 306 along its side. The channel wall 306 is highest at the proximal end 302 and gradually decreases in height as it moves longitudinally along the extension 131 until it reaches the distal end 304. Preferably, the channel wall 306 has a height of 0.9 mm at the proximal end 302 and tapers to 0 mm at the distal end 304.

[0041] In some embodiments of the present disclosure, the third distal end 304 of the extension 131 is provided with a C-shaped balloon wrap 308 on its underside. The C-shaped balloon wrap 308 is adapted to receive the balloon catheter 200 and to hold the inflatable balloon 220 of the balloon catheter 200. Preferably, the C-shaped balloon wrap 308 has a semicircular cross-section having the same diameter as the channel 126. Preferably, the C-shaped balloon wrap 308 is longitudinally connected to the extension 131 along the midpoint of its arc. Preferably, the C-shaped balloon wrap 308 has a length of 40 mm extending from the third distal end 304 of the extension 131.

[0042] According to some embodiments of the present disclosure, Figure 4A schematically shows the distal end of a biopsy needle 400 in a closed configuration, while Figure 4B schematically shows the distal end of a biopsy needle 400 in an open configuration. The biopsy needle 400 comprises a coring needle 500 and a stylet needle 600. The coring needle 500 is a thin-walled tube that slides freely on the stylet needle 600. The coring needle 500 has a cutting edge 537 with a tip 539 at its distal end that is adapted to cut into biopsy tissue. The stylet needle 600 may be a 16g needle having a sample collection recess 645 at its distal end 648 (see Figure 6B), with a smaller cross-sectional area than the rest of the stylet needle 600. The stylet needle 600 may have a tip 642 at its distal end 648 (see Figure 6B). The coring needle 500 and stylet needle 600 can be made from any medical-grade stainless steel, titanium, or metal alloy. The stylet needle 600 is inserted into the coring needle 500. In the closed configuration (see Figure 4A), the sample collection recess 645 forms a space between the coring needle 500 and the stylet needle 600 from which a sample of biopsy tissue is collected. The tip 539 of the cutting edge 537 of the coring needle 500 and the tip 642 of the stylet needle 600 are substantially opposite each other. In the open configuration (see Figure 4B), the stylet needle 435 advances relative to the coring needle 500 and enters the biopsy tissue. Subsequently, as the coring needle 500 advances and the biopsy needle 400 is in the closed configuration, the cutting edge 537 shears the biopsy tissue and the sample is collected in the sample collection recess 645. The entire stylet needle 600 or biopsy needle 400 can rotate within the bean-shaped lumen 106, thereby orienting the sharp tip 642 away from the extension 131 and preventing the sharp tip 642 from puncturing its characteristic portion.

[0043] According to some embodiments of the present disclosure, Figures 5A–5D schematically show a coring needle 500. According to some embodiments of the present disclosure, Figure 5A schematically shows a side view of the coring needle 500, Figure 5B schematically shows a bottom view of the coring needle 500, Figure 5C schematically shows a cross-section of the coring needle 500, and Figure 5D schematically shows the distal end 502 of the coring needle 500. The coring needle 500 comprises a distal end 502 and a proximal end 504. Preferably, the coring needle 500 is 500–1000 mm in length, ideally 918 mm. The proximal end 504 may be connected to a biopsy needle handle. The distal end 502 may be equipped with a cutting edge 537 having a tip 539 and a base 541 (see Figure 5D).

[0044] In some embodiments of this disclosure, the coring needle 500 is adapted to be more flexible by controlling the removal of material from the coring needle 500, such as by introducing a spiral cut of length "f" along the axial length with a pitch length "g" between each spiral. Preferably, the width of the spiral cut may be 0.01 to 0.3 mm, ideally 0.1 mm. Optionally, the width of the spiral cut may gradually increase between the distal end 502 and the proximal end 504 of the coring needle 500. Optionally, the width of the spiral cut may be 0.03 mm at the distal end 502 and gradually increase to a maximum of 0.3 mm at the proximal end 504 to minimize the loss of pressing force and allow for maximum flexibility. Those skilled in the art will understand that adding a spiral cut to the coring needle not only makes the coring needle 500 more flexible but also causes the coring needle 500 to behave more like a spring. By controlling the width of the spiral cut, the local flexibility of the coring needle can be programmed. Preferably, the starting point of the spiral cut at the distal end 502 of the coring needle 500 is located 2.5 mm away from the base 541 of the cutting edge 537 at the distal end 502 of the coring needle 500. Preferably, the end of the spiral cut at the proximal end 504 of the coring needle 500 is located 20 mm away from the proximal end 504 of the coring needle 500. The length "f" of the spiral cut can be any length extending along the coring needle 500. Optionally, there may be multiple spans of spiral cuts, having the same or different lengths along the length "f" extending along the coring needle 500, and having solid continuous sections between the spiral cuts, with the spiral cuts being 1 to 50 mm in length depending on the length of the coring needle 500 and the flexibility to be achieved. The pitch length "g" between each spiral may be any length. The pitch length "g" between each spiral may be constant or may vary along the total length "f" of the spiral cut. Preferably, the pitch length "g" between each spiral may be shorter at the distal end 502 and longer at the proximal end 504. Preferably, the pitch length "g" is 2 to 10 mm, ideally 6 mm.Optionally, the coring needle 500 may have different separate sections with different pitches to match different bends in the vascular system. At the most distal end 502 of the coring needle 500, the pitch length may be the shortest, for example, 2 mm, providing the most flexible tip for guiding the most bends. A second, more proximal separate section may have a pitch length of 4 mm to balance the flexibility of the coring needle 500 with its ability to transmit ejection force from the needle biopsy device. A third, most proximal separate section, closest to the proximal end 504 of the coring needle 500, may have the longest pitch length, for example, 6 mm, as it does not guide the vascular system much. Each section may be 10 to 500 mm in length depending on the expected shape of the vascular system to be guided. Between each separate section, there may be 0.1 mm to 5 mm sections of the coring needle 500 that do not have spiral cuts. Optionally, the pitch length may vary continuously across the entire coring needle 500 from 2 mm at the distal end to 6 mm at the proximal end. Those skilled in the art will understand that the pitch "g" of the coring needle 500 must be small enough so that each individual spiral segment does not take a linear orientation and each spiral adapts to the radius of the brachiocephalic vein when the coring needle 500 is guided through the needle guide lumen 104 near the brachiocephalic vein. If the spiral segments take a linear orientation, the ends of each spiral will be misaligned, and the relatively right-angle corners of each end may potentially wear the inside of the needle guide lumen 104. Also, those skilled in the art will understand that if the pitch "g" is too small, the sum of all the gaps between each spiral will be compressed during firing, effectively reducing the penetration depth of the coring needle 500, but this expected reduction in penetration depth can be compensated for by pre-adjusting the stroke of the firing mechanism of the coring needle 500.

[0045] In some embodiments of this disclosure, the coring needle 500 may have an outer diameter of "h" and an inner diameter of "k" (see Figure 5C). Preferably, the diameter "h" is 1 to 2 mm, ideally 1.65 mm. Preferably, the diameter "k" is 1 to 2 mm, ideally 1.47 mm.

[0046] In some embodiments of the present disclosure, the cutting edge 537 at the distal end 502 of the coring needle 500 may have a tip 539 and a base 541 (see Figure 5D). In some embodiments of the present disclosure, the cutting edge 537 is a continuous acute-angled surface along the outer circumference of the distal end 502. In some embodiments, the cutting edge 537 may have a Menghini point with a length of 2 to 4 mm, ideally 2.96 mm, a primary bevel angle 552 of 15 to 60 degrees, ideally 30 degrees, and a secondary bevel angle 554 of 5 to 30 degrees, ideally 12 degrees.

[0047] Figures 6A–6D schematically show a stylet needle 600 according to some embodiments of the present disclosure. According to some embodiments of the present disclosure, Figure 6A schematically shows a top view of the stylet needle 600, Figure 6B schematically shows a side view of the stylet needle 600, Figure 6C schematically shows the blade 650 of the stylet needle 600, and Figure 6D schematically shows a notch on the stylet needle 600. The stylet needle 600 comprises a fourth distal end 648 and a fourth proximal end 660. The proximal end 660 may be connected to a biopsy needle handle. The fourth distal end 648 comprises a blade 650 and a sample collection recess 645. The sample collection recess 645 has a distal end 644 and a proximal end 643. Preferably, the stylet needle 600 has a diameter of 1–2 mm, ideally 1.37 mm. Preferably, the sample collection recess 645 has a depth of 0.4 to 0.6 mm, ideally 0.55 mm. Those skilled in the art will understand that the depth of the sample collection recess should not exceed half the cross-sectional area of ​​the stylet needle 600. The sample collection recess 645 may have a surface between the distal end 644 and the proximal end 643, which may be flat or curved (concave). The concave surface allows for the collection of an increased volume of sample while maintaining similar rigidity to the shaft of the stylet needle 600. Adequate shaft rigidity is required so that the stylet needle 600 does not bend or curve significantly when puncturing the target tissue.

[0048] In some embodiments of this disclosure, the blade 650 has a leading edge 660, a trailing edge 670, a flat surface 680, and a base 662. The flat surface 680 connects the leading edge 660 and the trailing edge 670. The base 662 connects to the leading edge 660 at the tip 642. Preferably, the leading edge 660 has a vertical length from the tip 642 of 1 mm to 4 mm, ideally 2.9 mm. Preferably, the leading edge 660 has an angle of 110 to 170 degrees, ideally 155 degrees, from the base 662 of the blade 650. The trailing edge 670 connects the flat surface 680 and the sample collection recess 645. The trailing edge 670 contacts the proximal end 644 of the sample collection recess at point 672. Preferably, the trailing edge 670 has an angle between 90 and 165 degrees, ideally between 125 degrees, from the sample collection recess 645. Preferably, the flat surface 680 has a vertical length of 0.5 mm to 5 mm, ideally between 3 mm, from point 672.

[0049] In some embodiments of the present disclosure, the stylet needle 600 is adapted to be more flexible by introducing notches along its axial length "r" and having a pitch length "s" between each notch. Since the sample collection recess 645 has a smaller cross-sectional area than the rest of the stylet needle 600, the proximal end 643 of the sample collection recess 645 represents the fixed end of the cantilever compared to the distal end 648 that penetrates the parenchyma, thereby causing the maximum bending moment and stress concentration to occur at the proximal end 643 of the sample collection recess 645 due to the abrupt change in cross-sectional area in response to any force applied to the distal end 648 of the stylet needle 600. Therefore, notches 690 are introduced into the stylet needle 600 to reduce the tendency for the maximum bending moment in the stylet needle 600 to occur at the proximal end 643 of the sample collection recess 645. The notches 690 allow the stylet needle 600 to adopt a progressive rate of change in curvature within the more flexible spiral-cut coring needle 500, and as both advance through the needle guide lumen 104, the bending force is effectively distributed along the stylet needle 600 without being concentrated at the proximal end 643 of the sample collection recess 645, so that each notch itself becomes a stress concentration point. Therefore, those skilled in the art will understand that the length "r" and pitch "s" of the coring needle 500 are adjusted for stylet needles 600 of various gauges. Preferably, the pitch "s" is 0.5 to 5 mm, ideally 2 mm. The length "r" can be any length extending along the stylet needle 600. Preferably, the notches 690 have a width of 0.01 to 0.3 mm, ideally 0.1 mm. Preferably, the notches 690 have a depth of 0.1 to 0.55 mm, ideally 0.2 mm. Preferably, the notch 690 has a depth of no more than 30% of the diameter of the stylet needle 600 and is not deeper than the thinnest point on the sample collection recess 645, so as not to impair the overall strength of the stylet needle 600. Preferably, the notch 690 is deeper than its width to give a non-square contour to minimize interference with the spiral cut pattern. For example, the notch 690 may have a depth of 0.2 mm and a width of 0.1 mm.Preferably, the base of the notch 690 has a corner fillet to reduce stress concentration at the inner corner of the right-angle joint. Preferably, the notches 690 may be oriented offset from each other by 90 degrees, and the first notch 690 adjacent to the sample collection recess 645 is oriented parallel to the sample collection recess 645. It can be understood that the edges of the notch 690 on the stylet needle 600 are aligned so as not to interfere with the spiral cut pattern of the coring needle 500. This prevents snagging as the two slit surfaces pass each other.

[0050] In some embodiments of the present disclosure, Figure 7A schematically shows the distal end of a catheter body assembly 100 in a hepatic vein 404 having an uninflated inflatable balloon 220, while Figure 7B schematically shows the distal end of a catheter body assembly 100 in a hepatic vein 404 having an inflated inflatable balloon 220 and a biopsy needle 400 that penetrates the liver 402. The distal end of the catheter body assembly 100 can be guided through the venous system, through the inferior vena cava 406 to the liver 402, and enter a hepatic vein 404 such as the middle hepatic vein. Throughout the entire guidance, the biopsy needle 400 can be kept within the catheter body assembly 100 without exiting the distal exit 130.

[0051] In some embodiments of this disclosure, when the distal end of a catheter body assembly 100, which includes a balloon catheter 200 within a C-shaped balloon wrap 308, is positioned in a hepatic vein 404, the inflatable balloon 220 can be inflated to a certain diameter (e.g., up to 20% larger than the vein diameter) to secure the distal end and extension 131 of the catheter body assembly 100 within the hepatic vein 404. When the inflatable balloon 220 is inflated, the extension 131 and the C-shaped balloon wrap 308 are pressed against the vascular wall of the hepatic vein 404. Since the distal exit 130 from which the biopsy needle 400 exits is proximal to the inflated balloon 220, the biopsy needle 400 should be oriented obliquely towards the liver parenchyma 402 along the extension 131. Thus, the biopsy needle 400 enters the liver parenchyma 402 at an angle α between the central axis of the inflatable balloon 220 of the balloon catheter 200 and the central axis of the extension 131 (see Figure 7B). Before the inflatable balloon 220 is inflated, the angle α is 0 degrees. The angle α formed when the biopsy needle 400 is inserted into the liver 402 depends on the angle of the tapered portion 221 of the inflatable balloon 220. The lower the angle of the tapered portion 221 of the inflatable balloon, the smaller the offset of the extension 131. The biopsy needle 400 deviates less, and the penetration angle α becomes smaller. Therefore, the insertion angle α can be adapted to the human anatomical structure rather than being a predetermined angle. Preferably, the angle α is 5 to 20 degrees, preferably 10 to 15 degrees. The channel wall 306 along the extension 131 guides the biopsy needle 400 so that it does not deviate to the left or right as it advances into the liver 402.

[0052] This specification discloses various embodiments. Features of a particular embodiment may be combined with features of other embodiments. Thus, a particular embodiment may be a combination of features of multiple embodiments. The foregoing description of embodiments of the present invention is presented for illustrative and explanatory purposes. It is not intended to be exhaustive or to limit the invention to the exact forms disclosed. Those skilled in the art should understand that many modifications, variations, substitutions, alterations, and equivalents are possible in light of the above teachings. Accordingly, it should be understood that the appended claims are intended to include all such modifications and alterations that fall within the true spirit of the invention.

[0053] While certain features of the present invention are illustrated and described herein, many modifications, substitutions, alterations, and equivalents will be conceivable to those skilled in the art. Therefore, it should be understood that the appended claims are intended to include all such modifications and alterations that fall within the true spirit of the present invention.

Claims

1. A catheter body assembly including a catheter, wherein the catheter is It comprises a first elongated tube and a second elongated tube, The first elongated tube has a first lumen with a first proximal end and a first distal end, The second elongated tube shares a common wall with the first elongated tube, the common wall extends to form a C-shaped cross-section, the common wall defines a channel having a second proximal end and a second distal end, and the C-shaped cross-section has a lateral opening extending in the longitudinal direction. The catheter comprises a second tool for insertion into the channel of the second elongated tube, The second tool is a balloon catheter having a distal end for insertion into the channel of the second elongated tube, the section of the balloon catheter near the distal end having a balloon that, when inserted into a blood vessel of the target organ, inflates and secures an extension connected to the first distal end within the blood vessel near the biopsy site of the target organ. Catheter body assembly.

2. The catheter body assembly according to claim 1, wherein the first lumen has a kidney-shaped cross-section.

3. The catheter body assembly according to claim 2, wherein the common wall is located in the recess of the kidney-shaped cross-section of the first elongated tube.

4. The catheter body assembly according to any one of claims 1 to 3, wherein the first lumen has a cross-section with a closed curve shape having at least one recess.

5. The catheter body assembly according to any one of claims 1 to 4, wherein the common wall is located on the opposite side of the longitudinally extending lateral opening.

6. The catheter body assembly according to any one of claims 1 to 5, wherein the common wall has a thinner thickness compared to the other walls of the catheter.

7. The catheter body assembly according to any one of claims 1 to 6, wherein the extension further comprises a third proximal end and a third distal end, the third proximal end being connected to the first distal end of the first elongated tube.

8. The catheter body assembly according to claim 7, wherein the extension is an extension of the common wall.

9. The catheter body assembly according to claim 7 or 8, further comprising a first tool for insertion into the first lumen of the first elongated tube.

10. The catheter body assembly according to claim 9, wherein the first tool is a biopsy needle configured to penetrate into the tissue of the target organ at a predetermined angle between the central axis of the second tool and the extension, and to exit from the first distal end of the first lumen to obtain a biopsy sample of the target organ.

11. The catheter body assembly according to claim 10, wherein the extension further comprises a balloon wrap at the third distal end, and the balloon wrap is configured to receive the balloon of the balloon catheter.

12. The catheter body assembly according to claim 11, wherein the balloon wrap has a c-shaped cross-section.

13. The catheter body assembly according to any one of claims 7 to 12, wherein the extension portion is provided with a channel wall along the side of the extension portion.

14. The catheter body assembly according to claim 13, wherein the height of the channel wall decreases from the third proximal end to the third distal end.

15. The catheter body assembly according to any one of claims 1 to 14, wherein the first proximal end of the first elongated tube and the second proximal end of the second elongated tube are connected to a needle biopsy device.

16. The catheter body assembly according to claim 10, wherein the biopsy needle comprises a coring needle and a stylet needle.

17. The catheter body assembly according to claim 16, wherein the coring needle includes one or more spiral cuts extending longitudinally around and along the coring needle.

18. The catheter body assembly according to claim 17, wherein one or more spiral cuts have a constant pitch.

19. The catheter body assembly according to claim 18, wherein one or more spiral cuts have a variable pitch.

20. The catheter body assembly according to claim 16, wherein the stylet needle comprises notches arranged longitudinally along the periphery of the stylet needle.

21. The catheter body assembly according to claim 20, wherein the notch is deeper in depth than in width and is not square.

22. The catheter body assembly according to claim 20 or 21, wherein the base of the notch comprises one or more corner fillets.

23. The catheter body assembly according to any one of claims 20 to 22, wherein the notch includes two rows of notches located on the opposite side of the periphery.

24. The catheter body assembly according to any one of claims 16 to 23, wherein the stylet needle has a recess at the fourth distal end of the stylet needle, the recess being arranged longitudinally along the circumference of the stylet needle.

25. The catheter body assembly according to claim 24, wherein the recess has a flat contour.

26. The catheter body assembly according to claim 24, wherein the recess has a concave contour.

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