Drain and drainage apparatus

Abstract

This invention discloses a drainage tube and drainage device, relating to the field of medical device technology. The drainage tube has a flat end for insertion, with an outer diameter equal to or less than the diameter of the tube body from the insertion end to the exposed end. The drainage lumen is of uniform diameter, and the drainage inlet at the tip is large. The drainage device includes a drainage tube, a limiting incision knife, and a propulsion device: the limiting incision knife's handle limits the cutting depth to 3 to 10 mm at the tip, and the blade limits the incision length to 0.4 to 0.7 times the circumference of the drainage tube; the distal blunt end of the propulsion device protrudes 0.5 mm to 30 mm beyond the flat end, with a maximum outer diameter equal to the inner diameter of the drainage tube and abutting against the flat end face for force transmission, ensuring smooth insertion and no jamming upon withdrawal. The device may also include a limiting fastener to prevent backward movement and preset the insertion depth, as well as configurations such as long puncture needle insertion and direct insertion of the blunt end of a large drainage tube. This invention is applicable to bedside catheter placement under local anesthesia for conditions such as pneumothorax and pleural effusion, as well as deep tissue drainage catheter placement such as the biliary tract.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a tipless drainage tube and a drainage device including the drainage tube, which is suitable for bedside drainage under local anesthesia for non-cardiothoracic surgical diseases such as pneumothorax, hemothorax, and pleural effusion, as well as drainage tubes that establish drainage channels to deep tissues of the human body such as the bile duct and abdominal cavity through percutaneous puncture. Background Technology

[0002] Drainage tubes are among the most commonly used medical devices in clinical practice, widely used for the drainage treatment of diseases such as pneumothorax, hemothorax, pleural effusion, ascites, and biliary obstruction. In non-cardiothoracic surgery settings, many patients require rapid bedside or outpatient placement of drainage tubes under local anesthesia; such placements typically involve first making an incision in the skin with a scalpel, and then using a propulsion device to push the drainage tube into the body cavity or target tissue.

[0003] In existing technologies, to facilitate the passage of drainage tubes through skin incisions and into body cavities, the insertion end of the drainage tube typically has a fine tip (also known as a guide tip or transition section) with both its outer and inner diameters narrowed. The applicant has discovered the following technical problems with existing drainage tubes and insertion devices: Firstly, the tip narrows the drainage entrance.

[0004] The design of the fine tip is intended to facilitate the insertion of the drainage tube, but compared with the flat end, it significantly reduces the drainage inlet at the tip: the drainage lumen of the fine tip is narrowed, and a step or angle is formed between it and the main lumen of the tube, creating a drainage dead zone. Flocculent matter, blood clots, and necrotic tissue in the drainage fluid are easily retained at the tip and the step, causing the drainage tube to become blocked; the narrowed section also causes the cross-sectional area of ​​the drainage lumen to change along the length of the tube, affecting the patency and flow rate of the drainage.

[0005] Secondly, during insertion, the tip and the booster device get stuck together, making it difficult to remove the booster device. During the insertion process, the drainage tube is easy to retract or be inserted too deeply in one go.

[0006] When inserting a thin drainage tube, the tip of the push rod extends into the narrowed lumen of the fine tip to push the tube. Some tips are designed with a push step to cooperate with the push instrument. Sometimes, the push instrument passes over the push step and inserts into the tip. Due to the extremely small gap between the two, coupled with the radial compression of tissue rebound force, the tip of the push rod and the inner wall of the tip can easily get stuck together—especially when a limiting incision knife is not used and the procedure is performed by a doctor from a non-surgical department, or when the skin incision is too small or no scalpel is used. The resistance increases significantly when withdrawing the push rod. Forcibly pulling it out can cause the drainage tube to shift, dislodge, or even damage the tissue along the puncture path. At the same time, tissue resistance is transmitted through the drainage tube during insertion. If there is no axial restraint between the drainage tube and the push instrument, the drainage tube can slide proximally relative to the push instrument, resulting in incomplete placement and requiring repeated operations. Conversely, if the entire tube is pushed in too deeply in one operation, it can damage the tissue around the target organ, as the insertion depth lacks a pre-set limit for a single operation.

[0007] Third, there is no limit to the depth of skin incision.

[0008] Current insertion procedures use a regular scalpel to cut the skin, and the depth of the incision depends entirely on the surgeon's experience: if it is too shallow, the incision will be insufficient and the drainage tube will be difficult to insert; if it is too deep, it will damage subcutaneous blood vessels, muscles, or even deep organs.

[0009] Fourth, the incision length lacks limits, resulting in insufficient minimally invasiveness.

[0010] An incision that is too large will result in greater trauma, slower healing, and a higher risk of air and fluid leakage; an incision that is too small will make it difficult to insert the drainage tube. Similarly, when doctors in non-surgical departments perform the procedure, a lack of experience in selecting the appropriate incision length is a common cause of insertion difficulties, as there is a lack of specialized incision instruments that match the size of the drainage tube and allow for a limited incision length.

[0011] In addition, issues such as the retraction control of the drainage tube during insertion, the establishment of a channel through puncture of deep tissues (such as the bile duct), and the insertion of the tipless drainage tube have been addressed with sporadic fasteners, long puncture needles, and new designs for the thick drainage tube. However, no publicly available solutions have been found to integrate the tipless drainage tube and the limiting incision knife into a complete instrument combination. There is still a lack of systematic solutions for non-surgical doctors when performing the procedure.

[0012] Therefore, there is an urgent need for a drainage tube and matching drainage instruments with a large cephalic drainage inlet, smooth withdrawal of the assisting device during insertion, controllable insertion process (anti-backward movement, and pre-set single insertion depth), and appropriate limits on the depth and length of the skin incision, so that doctors in non-surgical departments can successfully perform bedside catheter placement under local anesthesia. Summary of the Invention

[0013] To address the problems existing in the prior art, the present invention provides a drainage tube and drainage device, the technical solution of which is as follows.

[0014] In a first aspect, the present invention provides a drainage tube, wherein the insertion end of the drainage tube is a flat end, and the outer diameter of the drainage tube is equal from its insertion end to its exposed end, or the outer diameter of the insertion end of the drainage tube is not greater than the outer diameter of the rest of the tube body.

[0015] In this text, "flat end" refers to the end face of the insertion end of the drainage tube being perpendicular to the axis of the drainage tube, and the tube wall at the end face having no inward or outward tapered transition, but the insertion port may have a smooth cut cross-section. In this text, the drainage tube is a thin drainage tube, i.e., a drainage tube with an outer diameter less than or equal to 16F; the thick drainage tube is a drainage tube with an outer diameter greater than 16F. Therefore, the drainage tube has a uniform drainage cavity from the insertion end to the exposed end: no narrowing sections, no step dead angles, the drainage fluid flows with a uniform cross-sectional area throughout, the drainage inlet at the head end is maximized, and it is not prone to stagnation and blockage.

[0016] The preferred embodiment of "the outer diameter of the insertion end is not greater than that of the tube body" is described in detail below (this preferred embodiment corresponds to the quantitative limitation of claim 2, and claim 1 includes a wider range including this preferred embodiment).

[0017] Preferably, the outer diameter of the insertion end is 85% to 99% of the outer diameter of the tube body, and the axial length of the insertion end is no more than three times the outer diameter of the tube body. This quantitative range allows the insertion end to form a "slightly smaller front end" insertion drag-reducing bevel, the technical basis of which is: Lower limit of outer diameter 85%: If the outer diameter of the inserted end is less than 85% of the outer diameter of the tube, the drainage inlet at the distal opening will be significantly reduced, and it will once again approach the old problem of "trading the drainage inlet for the convenience of insertion" in the traditional reduced diameter tip, thus losing the core benefit of the tipless design; 85% is the critical value to ensure that the drainage inlet is basically not reduced.

[0018] Outer diameter upper limit 99%: The closer the outer diameter is to the tube body, the gentler the drag reduction bevel, and the weaker the drag reduction effect. A micro-reduction diameter within 99% can produce a guiding and drag reduction effect at the moment of insertion without significantly weakening the advantages of tipless drainage and anti-clogging.

[0019] In addition, the design that the outer diameter of the insertion end is no larger than that of the tube body is also beneficial for the insertion of the drainage tube into the booster device: the bevel with a slightly reduced diameter guides the tip of the booster device at the moment of insertion into the skin, reducing the initial insertion resistance and allowing the tipless drainage tube to achieve insertion smoothness close to that of a tipped drainage tube.

[0020] Gradient implementation example: The outer diameter of the insertion end can be set to 85%, 90%, or 95% of the outer diameter of the tube body, with an axial length ranging from 2mm to 5mm. For example, for a drainage tube with an outer diameter of 12F (approximately 4mm), when the outer diameter of the insertion end is set to 95% (3.8mm) and the axial length is 5mm, the simulated tissue insertion resistance is reduced by approximately 10% to 20% compared to a tube with a constant diameter throughout, while the drainage inlet area is only slightly reduced, achieving a balance between insertion smoothness and drainage patency. The insertion end can be formed by grinding the outer surface of the tube wall, molding, or heat shrinking, and is integrally formed with the tube body.

[0021] Secondly, the present invention provides a drainage device, including a drainage tube, a limiting incision knife, and a propulsion device. The limiting incision knife includes a blade and a handle. The handle has a limiting portion for limiting the maximum cutting depth of the blade; the limiting width of the blade is used to limit the maximum incision length—that is, the limiting depth of the limiting portion corresponds to the depth of the incision, the limiting width of the blade corresponds to the length of the incision, and the incision length corresponds to the circumference of the drainage tube. The depth limiting of the blade can be implemented in three ways: the blade itself has a limiting step that determines the incision depth; or the handle has a limiting portion that limits the maximum cutting depth of the blade (in which case a blade without a limiting step can be used); or the depth limiting function of the handle and the depth limiting function of the blade work together to limit a uniform depth. The limiting part is the foremost end of the handle: the front end of an ordinary scalpel handle can serve as the limiting part. When the cutting reaches the predetermined depth, the front end of the handle directly abuts against the skin surface, preventing the blade from penetrating further. There is no need to set a special baffle on the handle. An ordinary scalpel with a limiting blade can be used to form a limiting cutting knife, achieving the lowest cost. The limiting part can also be the bent part or step part of the blade itself, the baffle set on the handle, or the limiting surface formed by the blade and the handle together.

[0022] The distance between the limiting part and the blade edge is preferably 3mm to 10mm: the full thickness of human skin is about 0.5mm to 4mm (about 0.5mm for eyelids, about 1.5mm to 3mm for the chest and abdomen, and up to 3mm to 4mm for the back, palms, and soles). The lower limit of 3mm ensures that the thinnest part of the skin is completely cut through, and the upper limit of 10mm ensures that after cutting through the thickest part, it only enters the superficial layer of subcutaneous fat and does not touch the muscle layer and fascia—achieving "just completely cutting the skin without deep cutting." The incision length limited by the blade is preferably 0.4 to 0.7 times the circumference of the drainage tube: when the incision length is equal to the circumference of the drainage tube, it fits perfectly. If it is slightly larger or smaller, the elasticity of the skin and subcutaneous tissue can still allow for smooth insertion and maintain a close fit, taking into account both minimal invasiveness and airtightness.

[0023] The insertion device includes an insertion rod for inserting into the lumen of the drainage tube. The distal end of the insertion rod is blunt-tipped, protruding beyond the flat end of the insertion tube. The protrusion distance is preferably 0.5mm to 30mm; for superficial insertion, 2mm to 5mm is preferred; and for insertion through an established long channel, 10mm to 30mm can be used. The insertion device can be an insertion rod or an insertion handle. The insertion handle includes a gripping part and a push rod part. The blunt tip of the push rod part also protrudes beyond the flat end and is defined by the same protrusion distance range. During insertion, the blunt tip protruding beyond the flat end contacts the tissue first, acting as a guide, expanding, and dispersing stress. The blunt tip end face and the flat end face are of equal diameter, transmitting force through contact, and there is no narrowing gap between them that could cause jamming. After insertion, the insertion device can be smoothly withdrawn. The insertion rod or insertion handle may have an axially continuous hollow channel for a guidewire to pass through or for connection to a syringe.

[0024] Thirdly, the present invention provides a drainage device, including a drainage tube, a limiting incision knife, a pushing device, and a limiting fastener. The limiting fastener includes a clamp that is closably connected to the pushing device, which, during insertion, surrounds and fixes the connection between the drainage tube and the pushing device, restricting the proximal movement of the drainage tube relative to the pushing device and preventing insertion backward. Furthermore, the limiting fastener can also be used to preset the insertion depth for a single operation, as detailed below.

[0025] The limiting fastener is fixed at a predetermined distance from the insertion end of the drainage tube. This predetermined distance is set based on the preoperatively determined insertion depth—for example, in bedside pleural catheter placement, the length is set according to the chest wall thickness measured by ultrasound. During insertion, the surgeon pushes the assist device, and the drainage tube follows. When the limiting fastener, along with the catheter, reaches the skin surface, its contact with the skin prevents the catheter from penetrating further—the insertion depth of a single push is preset to the predetermined distance, avoiding excessive insertion that could damage organs or tissues. If adjustment is needed, the limiting fastener can be loosened, its fixed position on the drainage tube changed, and the tube pushed again, achieving segmented and controllable progressive insertion. Once the tube is in place, the limiting fastener can be released to remove the assist device.

[0026] Therefore, the limiting fastener has three functions: first, it surrounds and fixes the connection between the drainage tube and the booster device to prevent the drainage tube from moving backward during insertion; second, it presets the single insertion depth at a predetermined distance from the insertion end of the drainage tube to prevent excessive insertion at one time; and third, it acts as an unlocking device, which can be opened after the tube is in place to smoothly remove the booster device.

[0027] Fourthly, the present invention also provides a drainage device, including a drainage tube, a limiting incision knife, a propulsion device, and a long puncture needle, for inserting a thin drainage tube into internal tissues (such as deep tissues like the bile duct via percutaneous transhepatic puncture). The limiting incision knife is used to cut the skin before puncture, and its structure is the same as described in the second aspect (the limiting part of the handle limits the cutting depth to 3mm to 10mm, and the limiting width of the blade limits the incision length). The propulsion device has a hollow channel extending axially; the long puncture needle can be inserted into the hollow channel, with the needle tip protruding from the distal end of the propulsion device, for puncturing human tissue to facilitate the insertion of the drainage tube; after puncture, the needle tip is aspirated through the hollow channel for confirmation or guide wire is advanced, and then the drainage tube is inserted along the channel. In the puncture state, the needle tip protrudes to achieve puncture, and in the insertion state, the blunt tip protrudes to achieve pilot insertion—the two "protrusions" correspond to two working conditions.

[0028] Fifthly, the present invention provides a drainage device for directly inserting a thick drainage tube with a blunt-tipped instrument: the insertion end of the thick drainage tube is a flat end, and the outer diameter is equal from the insertion end to the exposed end, or the outer diameter of the insertion end is not greater than the tube body; the propulsion device is a thick propulsion device adapted to the thick drainage tube, and its distal blunt tip protrudes from the flat end of the insertion end of the thick drainage tube, playing a leading expansion role, so that the thick drainage tube with an outer diameter greater than 16F can be directly inserted through the skin incision without the need for a puncture needle to pre-establish a channel and without a tip. The thick-type booster device can be a thick-type booster rod or a thick-type short booster handle. The thick-type booster rod or thick-type short booster handle can have an axially continuous hollow channel for the guidewire to pass through or connect to a syringe. The maximum outer diameter of the blunt tip of the thick-type booster device is equal to the inner diameter of the thick-type drainage tube. The distal end face of the blunt tip abuts against the flat end face of the insertion end of the thick-type drainage tube, transmitting force through end-face contact. The limiting incision knife is used for direct insertion before skin incision, and its structure is the same as described in the second aspect. The dilator is detailed below.

[0029] The dilator has a tapered tip and a body of equal diameter, the outer diameter of which matches the outer diameter of the drainage tube. "Matching" means that the outer diameter of the equal-diameter portion of the dilator is equal to or slightly larger than the outer diameter of the drainage tube (preferably equal to), so that the expanded skin channel can just accommodate the drainage tube. If the outer diameter is significantly larger than the outer diameter of the drainage tube, the channel becomes loose, increasing the risk of air and fluid leakage; if it is smaller than the outer diameter of the drainage tube, insufficient expansion and difficulty in insertion occur. In use, the tapered tip of the dilator is first inserted through the incision, and the skin and subcutaneous tissue are expanded through the equal-diameter body to form a skin channel. After withdrawing the dilator, the drainage tube is inserted along the channel. The dilator is particularly suitable for large drainage tubes with an outer diameter greater than 16F: large drainage tubes have a large diameter and significant tissue stretch; dilation before insertion can significantly reduce insertion resistance (roughly estimated at 30-50%) and reduce incision tearing. The dilator can be made of medical polymer materials, similar in structure to a long-pointed needle outer tube, or a long-pointed needle outer tube can be used directly.

[0030] Regarding the selection of drainage tube outer diameter: The drainage tubes of this invention cover all commonly used clinical tube diameters. Generally speaking, thin drainage tubes with an outer diameter less than or equal to 16F are suitable for bedside placement under local anesthesia for pneumothorax, pleural effusion, etc.; thick drainage tubes with an outer diameter greater than 16F are suitable for drainage of viscous drainage materials such as hemothorax and empyema. Thin drainage tubes and drainage tubes with slightly smaller tips can be easily inserted by means of a protruding blunt tip; it is recommended to use limiting fasteners for drainage tubes of the same diameter throughout; it is recommended to pre-expand the passage with a dilator tube and insert the thick drainage tube directly using a blunt tip.

[0031] Beneficial effects: Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The insertion end of the drainage tube is a flat end with a constant diameter, maximizing the drainage inlet at the head end. The drainage cavity has no narrowing sections or dead angles, and the drainage fluid flows with a constant cross-sectional area throughout, significantly reducing the incidence of blockage. 2. The blunt end of the push rod is in contact with the flat end face of the same diameter, eliminating the jamming gap between the inner cavity of the traditional fine tip and the push rod. After insertion, the push device can be smoothly withdrawn, avoiding displacement of the drainage tube and tissue damage caused by forced tube removal. 3. The blunt tip protruding from the flat end plays a guiding and expanding role during insertion, making the insertion resistance of the tipless drainage tube close to or even lower than that of the traditional tipped drainage tube, overcoming the technical prejudice that "it is difficult to insert without a tip". The same blunt tip insertion principle can also be applied to the direct insertion of the thick drainage tube. 4. The design of the outer diameter of the insertion end not being larger than that of the tube body is conducive to the insertion of the auxiliary device into the drainage tube: the micro-diameter bevel guides the device at the moment of insertion into the skin, reducing the initial insertion resistance and making the tipless drainage tube achieve a smooth insertion similar to that of a tipped drainage tube. 5. The limiting incision knife controls the incision depth by limiting the depth of the limiting part and controls the incision length by limiting the width of the blade. The front end of a regular knife handle can be used as the limiting part, and a regular scalpel with a limiting blade can be used to form a limiting incision knife. The incision depth and length are adapted to the drainage tube and human tissue, taking into account the safety of deep tissues, minimal invasiveness and incision closure, so that doctors in non-surgical departments can complete standardized skin incisions without experience. 6. The limiting fastener prevents the drainage tube from retracting during insertion and can preset the insertion depth for a single operation. Insertion stops when the limiting fastener touches the body surface, avoiding organ and tissue damage caused by excessive insertion in one operation. 7. The long puncture needle is used in conjunction with the hollow channel of the same assist device, so that the same device set can cover both bedside local anesthesia insertion and percutaneous drainage of deep tissues such as the hepatobiliary tract. Puncture, aspiration confirmation and catheter placement are completed continuously through the same channel. 8. The thick drainage tube adopts a new design with a blunt end and blunt tip for direct insertion. The large inner lumen drainage tube with an outer diameter greater than 16F can be smoothly inserted without a tip or puncture needle guidance, taking into account both the drainage needs of viscous drainage materials and the safety of insertion. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of the curved flat-mouth drainage tube without traction wire of the present invention.

[0033] Figure 2 This is a schematic diagram of the straight, flat-mouthed drainage tube without a traction wire according to the present invention.

[0034] Figure 3 This is a schematic diagram of the curved flat-mouth drainage tube with traction line of the present invention.

[0035] Figure 4 This is a schematic diagram of the solid blunt-headed long push rod of the present invention.

[0036] Figure 5 This is a schematic diagram of the blunt-headed long push rod with an axial hollow channel of the present invention.

[0037] Figure 6 This is a schematic diagram of the assembly structure of the straight drainage tube with traction line and the long push rod of the present invention.

[0038] Figure 7 This is a schematic diagram of the structure of the limiting fastener of the present invention.

[0039] Figure 8 This is a schematic diagram of the assembly structure of the limiting fastener, the curved drainage tube, and the blunt-headed long push rod of the present invention.

[0040] Figure 9 This is a schematic diagram of the structure of the short booster handle in this invention.

[0041] Figure 10 This is a schematic diagram of the structure of the short booster handle with an axial hollow channel of the present invention.

[0042] Figure 11 This is a schematic diagram of the blunt-tipped push rod with a gripping handle of the present invention.

[0043] Figure 12 This is a schematic diagram of the assembly structure of the drainage tube without traction line and the short booster handle of the present invention.

[0044] Figure 13 This is a schematic diagram of the front end of the limiting cutting blade with limiting steps of the present invention.

[0045] Figure 14 This is a schematic diagram of the overall structure of the limiting cutter with a handle limiting part of the present invention.

[0046] Figure 15 This is a schematic diagram of the assembly structure of the puncture and insertion instrument of the present invention, which consists of a thin drainage tube, a long puncture needle, and a long pointed needle outer tube.

[0047] Figure 16This is a schematic diagram of the assembly structure of the thin drainage tube of the present invention with a pointed bullet-shaped blunt-tipped short booster handle.

[0048] Figure 17 This is a schematic diagram of the assembly structure of the puncture and insertion instrument of the present invention, which consists of a thick drainage tube, a long puncture needle, and a long pointed needle outer cannula.

[0049] Figure 18 This is a schematic diagram of the assembly structure of the thick drainage tube and the blunt-tipped short booster handle of the present invention.

[0050] In the diagram: 11. Catheter; 12. Front drainage hole; 13. Side drainage hole; 14. Traction line; 15. Locking block; 18. Large drainage tube; 21. Scalpel; 22. Blade (blade can be Λ-shaped, dome-shaped, single-sided arc-shaped, rectangular, or chamfered rectangle); 23. Blade handle; 25. Blade limiting step; 31. Push rod; 32. Short push handle; 33. Push rod part of short push handle; 34. Grip part of short push handle (olive-shaped, straight rod-shaped, T-shaped); 36. Blunt tip (can be semi-circular, bullet-shaped, pointed bullet-shaped, flat-headed, or truncated conical); 38. Hollow channel; 41. Limiting fastener; 42. Clamp; 51. Long needle; 52. Tip of long needle; 53. Outer tube of long needle. Detailed Implementation

[0051] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention. Where there is no conflict, the following embodiments and their technical features can be combined with each other.

[0052] In this article, "distal end" refers to the end of the instrument that is closest to the human body and enters the body first, while "proximal end" refers to the end that is closest to the surgeon and exposed on the body. The "insertion end" of the drainage tube is its distal end, and the "exposed end" is its proximal end. In this article, drainage tubes with an outer diameter less than or equal to 16F are called thin drainage tubes, and drainage tubes with an outer diameter greater than 16F are called thick drainage tubes. "Flat end" refers to the end face of the insertion end of the drainage tube being perpendicular to the axis of the drainage tube, and the tube wall at the end face having no inward or outward tapered transition, and the insertion port may have a smooth incision section. Example 1: Tipless flat-mouth drainage tube

[0053] like Figures 1 to 3 As shown, this embodiment provides a drainage tube, including a conduit 11. The insertion end of the conduit 11 is a flat end. The conduit 11 has a front drainage hole 12 and may also have a side drainage hole 13. Figure 1 The image shows a curved, flat-mouthed drainage tube without a traction cable. Figure 2 The image shows a straight, flat-mouthed drainage tube without a traction cable. Figure 3The diagram shows a curved, flat-mouthed drainage tube with a traction line. The drainage tube with the traction line also includes a traction line 14 and a locking block 15 connected to the traction line 14. The traction line 14 is inserted into the catheter 11. Pulling the traction line 14 and locking it with the locking block 15 can keep the insertion end of the drainage tube in a curved shape to meet the indwelling needs in cavities such as the thoracic cavity.

[0054] In this embodiment, the insertion end of the drainage tube does not have the fine tip (guide head, transition section) of traditional drainage tubes; its outer diameter is equal from the insertion end to the exposed end. Alternatively, the outer diameter of the insertion end of the drainage tube is not greater than the outer diameter of the rest of the tube body. Therefore, the drainage tube has a uniform drainage lumen from the insertion end to the exposed end: the drainage lumen has no narrowing sections or dead angles, the drainage inlet at the tip is maximized, and the drainage fluid flows with a uniform cross-sectional area throughout the entire flow. Flocculent matter, blood clots, and necrotic tissue are less likely to accumulate at the tip, significantly reducing the incidence of blockage.

[0055] As a preferred option, the outer diameter of the insertion end is 85% to 99% of the outer diameter of the rest of the drainage tube, and the axial length of the insertion end is no more than three times the outer diameter of the drainage tube. The reason for setting the lower limit of the outer diameter to 85% is that if the outer diameter of the insertion end is less than 85% of the outer diameter of the tube, the drainage inlet at the distal opening will be significantly reduced, reverting to the drawback of the traditional reduced-diameter tip that "trades drainage inlet for insertion convenience". The reason for setting the upper limit of the outer diameter to 99% is that the closer the outer diameter is to the tube body, the gentler the drag-reducing bevel, and the weaker the drag-reducing effect during insertion. A micro-reduction within 99% can provide guidance and drag reduction at the moment of insertion without significantly weakening the drainage and anti-clogging advantages of the tipless design.

[0056] Specifically, the outer diameter of the insertion end can be set to 85%, 90%, or 95% of the outer diameter of the tube body, and the axial length can be 2mm to 5mm. Taking a drainage tube with an outer diameter of 12F (approximately 4mm) as an example, when the outer diameter of the insertion end is 95% (i.e., 3.8mm) and the axial length is 5mm, the simulated tissue insertion resistance is reduced by approximately 10% to 20% compared to a tube with a constant diameter throughout, while the drainage inlet area is only slightly reduced, achieving a balance between insertion smoothness and drainage patency. The insertion end can be formed by grinding the outer surface of the tube wall, molding, or heat shrinking, and is integrally formed with the tube body.

[0057] The drainage tubes in this embodiment cover all commonly used clinical tube diameters: thin drainage tubes with an outer diameter less than or equal to 16F are suitable for bedside placement under local anesthesia for pneumothorax, pleural effusion, etc.; thick drainage tubes 18 with an outer diameter greater than 16F are suitable for drainage of viscous drainage materials such as hemothorax and empyema. For the specific structure and placement method of the thick drainage tube 18, please refer to Embodiment Seven. Example 2: Booster (combined with) Figures 4 to 6 , Figures 9 to 12 )

[0058] like Figures 4 to 6 , Figures 9 to 12 As shown, this embodiment provides a pushing device for inserting a drainage tube into the lumen and pushing the drainage tube through a skin incision into the human body. The pushing device can be a pushing rod 31 or a pushing handle; the pushing handle can be a short pushing handle 32, which includes a gripping part 34 and a pushing part 33. The gripping part 34 can be olive-shaped, straight, or T-shaped to adapt to different surgeons' gripping habits and pushing force methods.

[0059] Figure 4 The image shows a solid blunt-headed long push rod 31; Figure 5 The image shows a blunt-tipped long push rod 31 with an axial hollow channel 38. The hollow channel 38 extends along the axial direction of the push rod 31 and allows a guide wire to pass through or be connected to a syringe. Figure 6 The diagram shows the assembly structure of a straight drainage tube with a traction line and a long push rod 31, with the long push rod 31 inserted into the inner cavity of the drainage tube. Figure 9 The solid short booster handle 32 is shown. Figure 10 The short booster handle 32 with an axial hollow channel 38 is shown. Figure 11 The image shows a blunt-tipped push rod 31 with a grip handle; Figure 12 The diagram shows the assembly structure of the drainage tube without the traction line and the short booster handle 32.

[0060] The distal end of the assist device is a blunt tip 36. The blunt tip 36 protrudes from the flat end of the drainage tube insertion end, and its shape can be semi-circular, bullet-shaped, pointed bullet-shaped, flat-headed, or truncated conical. During insertion, the blunt tip 36 protruding from the flat end contacts the tissue before the tube opening, acting as a guide, expanding, and dispersing stress, so that the insertion resistance of the tipless drainage tube is close to or even lower than that of traditional tipped drainage tubes.

[0061] The maximum outer diameter of the blunt tip 36 is equal to the inner diameter of the drainage tube. The distal end face of the blunt tip 36 is used to abut against the flat end face of the insertion end of the drainage tube, transmitting force through end-face contact. Because the blunt tip 36 and the flat end face abut against each other with equal diameter, there is no narrow gap between them that can jam, as is the case with the traditional fine tip lumen and the push rod. Even under radial compression from tissue rebound force, the pusher will not jam against the tip of the drainage tube. After insertion, it can be smoothly withdrawn, avoiding displacement, dislodgement, and tissue damage along the puncture path caused by forced removal of the tube. Example 3: Limiting fastener (combined with) Figure 7 , Figure 8 )

[0062] like Figure 7 , Figure 8 As shown, this embodiment provides a limiting fastener 41, which is used in conjunction with the aforementioned drainage tube and booster device. The limiting fastener 41 includes a clamp 42 that is closably connected to the booster device; Figure 8The diagram shows the assembly structure of the limiting fastener 41, the curved drainage tube, and the blunt-tipped long push rod 31. During the insertion operation, the clamp 42 surrounds and fixes the connection between the drainage tube and the push device, restricting the movement of the drainage tube relative to the push device towards the proximal end, thereby preventing the drainage tube from retracting or being improperly placed due to tissue resistance being transmitted through the drainage tube during the insertion process.

[0063] Furthermore, the limiting fastener 41 can also be used to preset the insertion depth for a single operation. The limiting fastener 41 is fixed at a predetermined distance from the insertion end of the drainage tube. This predetermined distance is set according to the insertion depth determined preoperatively—for example, when placing a tube in the pleural cavity at the bedside, the length is set according to the chest wall thickness measured by ultrasound. During the insertion operation, the surgeon pushes the assist device, and the drainage tube moves forward accordingly. When the limiting fastener 41 enters with the drainage tube and reaches the skin surface, the contact between the limiting fastener 41 and the body surface prevents the drainage tube from going further. The insertion depth for a single push is thus preset to this predetermined distance, avoiding organ and tissue damage caused by excessive insertion in one go. If further insertion is required, the clamp 42 can be loosened, its fixed position on the drainage tube changed, and then it can be pushed again, achieving segmented and controllable progressive insertion.

[0064] Therefore, the limiting fastener 41 has three functions: first, it surrounds and fixes the connection between the drainage tube and the booster device, preventing the drainage tube from moving backward during insertion; second, it presets the single insertion depth at a predetermined distance from the insertion end of the drainage tube, preventing excessive insertion at once; and third, it acts as an unlocking device, allowing the booster device to be easily removed by opening the clamp 42 after the tube is in place. For drainage tubes with a constant diameter throughout, it is recommended to use the limiting fastener 41 of this embodiment. Example 4: Limiting cutting knife (combined with) Figure 13 , Figure 14 )

[0065] like Figure 13 , Figure 14 As shown, this embodiment provides a limiting incision knife, including a blade 22 and a handle 23, used to cut the skin before inserting a drainage tube, and to simultaneously limit the depth and length of the incision by mechanical limiting. The shape of the blade 22 can be Λ-shaped, dome-shaped, single-sided arc-shaped, regular rectangle, or chamfered rectangle.

[0066] The cutting depth limit of blade 22 can be implemented in three ways: First, as shown in the figure... Figure 13 As shown, the blade 22 itself has a limiting step 25 (blade limiting step) that determines the cutting depth; secondly, as... Figure 14As shown, the handle 23 is provided with a limiting part, which is used to limit the maximum cutting depth of the blade 22. At this time, a blade 22 without a limiting step can be used. Thirdly, the depth limiting function of the handle 23 and the depth limiting function of the blade 22 work together to limit a uniform depth. The limiting part is the foremost end of the handle 23: the front end of an ordinary handle can serve as the limiting part. When the cutting reaches the predetermined depth, the front end of the handle directly abuts against the skin surface, preventing the blade 22 from going deeper. There is no need to set a special baffle on the handle 23. An ordinary scalpel with a limiting blade is used to form a limiting cutting knife. The limiting part can also be the bent part or step of the blade 22 itself, the baffle set on the handle 23, or the limiting surface formed by the blade 22 and the handle 23.

[0067] The distance between the limiting part and the 22 blade edges is 3mm to 10mm. The full thickness of human skin is approximately 0.5mm to 4mm (approximately 0.5mm for eyelids, 1.5mm to 3mm for the chest and abdomen, and up to 3mm to 4mm for the back, palms, and soles of the feet): the lower limit of 3mm ensures that the thinnest part of the skin can be completely cut through, and the upper limit of 10mm ensures that after cutting through the thickest part of the skin, the blade tip only enters the superficial layer of subcutaneous fat and does not touch the muscle fascia, achieving "just completely cutting the skin without deep cutting", avoiding damage to subcutaneous blood vessels, muscles, and even deep organs.

[0068] The limiting width of the blade 22 is used to limit the maximum incision length. The limiting width of the blade 22 corresponds to the length of the incision, and the incision length corresponds to the circumference of the drainage tube. Preferably, the incision length limited by the limiting width of the blade 22 is 0.4 to 0.7 times the outer circumference of the drainage tube: when the incision length is equal to the outer circumference of the drainage tube, it fits perfectly; if it is slightly larger or smaller, the elasticity of the skin and subcutaneous tissue allows for smooth insertion and maintenance of fit, balancing minimally invasiveness and incision tightness, reducing the risk of air and fluid leakage. With the help of depth and length limiting, doctors in non-surgical departments can complete a standardized skin incision that matches the size of the drainage tube without prior skin incision experience. Example 5: Basic drainage device (combined with) Figures 1 to 14 )

[0069] This embodiment provides a drainage device, including a drainage tube, a limiting incision knife, and a pushing device. The drainage tube is the drainage tube described in Embodiment 1, the limiting incision knife is the limiting incision knife described in Embodiment 4, and the pushing device is the pushing device described in Embodiment 2. The pushing rod 31 (or the pushing rod portion 33 of the short pushing handle 32) of the pushing device is used to insert into the inner cavity of the drainage tube, and its distal blunt end 36 protrudes from the flat end of the insertion end of the drainage tube. The limiting incision knife, the pushing device, and the drainage tube cooperate to realize the insertion of the drainage tube into the human body through a skin incision. The drainage device of this embodiment may also include the limiting fastener 41 described in Embodiment 3.

[0070] In use, the surgeon first makes an incision in the skin at the predetermined insertion site using a limiting incision scalpel: the limiting part (or the blade limiting step 25) abuts against the skin surface, limiting the incision depth to 3mm to 10mm, just enough to completely cut the skin; the limiting width of the blade 22 limits the incision length to 0.4 to 0.7 times the outer circumference of the drainage tube. Then, the flat end of the drainage tube equipped with the pushing device is aligned with the incision, and the pushing device is pushed: the blunt tip 36 protruding from the flat end first contacts and expands the tissue, and the drainage tube follows the blunt tip 36 through the incision into the body. The distal end face of the blunt tip 36 and the flat end face are of equal diameter and abut against each other to transmit force. If a limiting fastener 41 is used, the clamp 42 is wrapped around and fixed to the connection between the drainage tube and the pushing device before pushing, and the distance between the clamp 42 and the insertion end is set according to the insertion depth determined preoperatively. Pushing continues until the clamp 42 abuts against the body surface. After the tube is in place, open clamp 42 and remove the booster device, leaving the drainage tube in place, thus completing the tube placement. Example 6: Puncture-insertion type drainage device (combined with Figure 15 , Figure 17 )

[0071] like Figure 15 , Figure 17 As shown, this embodiment provides a puncture-insertion type drainage device for percutaneous puncture to establish a drainage channel to deep human tissues such as the bile duct and abdominal cavity, including a drainage tube, a limiting incision knife, a propulsion device and a long puncture needle (long pointed needle 51). Figure 15 The diagram shows the assembly structure of a puncture insertion instrument consisting of a thin drainage tube, a long puncture needle, and a long pointed needle outer tube 53. Figure 17 The diagram shows the assembly structure of a puncture insertion instrument consisting of a thick drainage tube 18, a long puncture needle, and a long pointed needle outer tube 53.

[0072] The long needle 51 has a pointed end 52. The long needle 51 can be inserted into the hollow channel 38 of the booster device, with the needle tip (pointed end 52) protruding from the distal end of the booster device. A long needle outer tube 53 can also be fitted over the long needle 51 for puncturing human tissue to facilitate the insertion of the drainage tube. In the puncture state, the pointed end 52 protrudes from the distal end of the booster device to achieve puncture; in the insertion state, the blunt end 36 protrudes from the flat end of the drainage tube to achieve pilot expansion—the two "protrusions" correspond to the puncture and insertion states, respectively.

[0073] In use, the skin is first cut open with a limiting incision knife, and then the long needle 51 (the tip 52 protrudes from the distal end of the pushing device) which is inserted into the hollow channel 38 of the pushing device and fitted with a long needle sheath 53 is punctured through the incision to enter the target tissue (such as percutaneous transhepatic biliary puncture). After the puncture is in place, the long needle 51 can be withdrawn, and the guide wire can be withdrawn through the long needle sheath 53 for confirmation or inserted. Then the guide wire is left in the body, and the drainage tube is pushed in along the established channel. The guide wire is withdrawn, and the drainage tube is left in place to complete the deep tissue placement. Example 7: Direct insertion of a large-diameter drainage tube into a drainage device (combined with...) Figure 16 , Figure 18 )

[0074] like Figure 16 , Figure 18 As shown, this embodiment provides a drainage device for directly inserting a thick drainage tube 18 with a blunt-tipped instrument, including the thick drainage tube 18, a limiting incision knife, and a pushing device. The insertion end of the thick drainage tube 18 is a flat end, and its outer diameter is equal from the insertion end to the exposed end, or the outer diameter of its insertion end is not greater than the tube body, with the specific structure being the same as in Embodiment 1. The limiting incision knife includes a blade 22 and a handle 23. The handle 23 has a limiting part to limit the maximum cutting depth of the blade 22, and the limiting width of the blade 22 limits the maximum incision length, with the specific structure being the same as in Embodiment 4.

[0075] The booster device is a thick-type booster device adapted to the thick drainage tube 18. It can be a thick-type booster rod 31 or a thick-type short booster handle 32, and can have a hollow channel 38 that runs through the axis for the guide wire to pass through or connect to the syringe. The distal blunt end 36 of the thick-type booster device protrudes from the flat end of the insertion end of the thick drainage tube 18. The maximum outer diameter of the blunt end 36 is equal to the inner diameter of the thick drainage tube 18. The distal end face of the blunt end 36 abuts against the flat end face of the insertion end of the thick drainage tube 18, and the end face abuts against the force transmission. Figure 16 The diagram shows the assembly structure of the thin drainage tube with the pointed bullet-shaped blunt-tipped short booster handle 32. Figure 18 The diagram shows the assembly structure of the coarse drainage tube 18 with the blunt-tipped short push handle 32. During insertion, the blunt tip 36 protruding from the flat end acts as a pilot expander, allowing the coarse drainage tube 18, with an outer diameter greater than 16F, to be directly inserted through the skin incision without the need for a pre-established channel by a puncture needle or a pointed tip, thus balancing the drainage needs of viscous drainage materials with insertion safety.

[0076] Furthermore, to reduce the insertion resistance of the coarse drainage tube 18, the drainage device in this embodiment can also be equipped with an dilator. The dilator has a tapered tip and a constant-diameter body, the outer diameter of which matches the outer diameter of the drainage tube—that is, equal to or slightly larger than the outer diameter of the drainage tube (preferably equal to): if it is significantly larger than the outer diameter of the drainage tube, the skin channel formed by the dilation will be loose, increasing the risk of air and fluid leakage; if it is smaller than the outer diameter of the drainage tube, the dilation will be insufficient, making insertion difficult. In use, the tapered tip of the dilator is first inserted into the incision, and the skin and subcutaneous tissue are dilated through the constant-diameter body to form a skin channel that just accommodates the drainage tube. After the dilator is withdrawn, the drainage tube is inserted along the channel. The dilator is particularly suitable for coarse drainage tubes 18 with an outer diameter greater than 16F: the coarse drainage tube 18 has a large diameter and significant tissue stretching; dilation before insertion can significantly reduce the insertion resistance (roughly estimated at 30% to 50%) and reduce incision tearing. The dilator can be made of medical polymer material and has a similar structure to the long needle outer tube 53. Alternatively, the long needle outer tube 53 can be used directly as the dilator.

[0077] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention (e.g., substitution of the shape of the blunt tip 36, substitution of the shape of the gripping part 34, substitution of the implementation form of the limiting part, etc.) should be included within the protection scope of the present invention.

Claims

1. A drainage tube, wherein the insertion end of the drainage tube is a flat end, characterized in that: The outer diameter of the drainage tube is equal from its insertion end to its exposed end, or the outer diameter of the insertion end of the drainage tube is not greater than the outer diameter of the rest of the tube body.

2. The drainage tube according to claim 1, characterized in that: The outer diameter of the insertion end of the drainage tube is 85% to 99% of the outer diameter of the rest of the drainage tube.

3. A drainage device, comprising a drainage tube, a limiting incision knife, and a propulsion device; The drainage tube is the drainage tube according to claim 1 or 2; The limiting cutting knife includes a blade and a handle; the blade has a limiting step that defines the cutting depth, used to limit the cutting depth; the handle has a limiting part, which is the foremost end of the handle, used to limit the maximum cutting depth of the blade, in which case a blade without a limiting step can be used; the depth limiting function of the handle and the depth limiting function of the blade can work together to limit a uniform depth; the limiting depth of the limiting part corresponds to the cutting depth, the limiting width of the blade is used to limit the maximum cutting length, the limiting width of the blade corresponds to the cutting length, and the cutting length corresponds to the circumference of the drainage tube; The booster device includes a booster rod, which is used to insert into the inner cavity of the drainage tube. The distal end of the booster rod is blunt, and the blunt end protrudes from the flat end of the insertion end of the drainage tube. The limiting incision knife, the booster device, and the drainage tube work together to allow the drainage tube to be inserted into the human body through a skin incision.

4. A drainage device, comprising a large drainage tube, a limiting incision knife, and a propulsion device; The insertion end of the coarse drainage tube is a flat end, and the outer diameter of the coarse drainage tube is equal from its insertion end to its exposed end, or the outer diameter of the insertion end of the coarse drainage tube is not greater than the outer diameter of the rest of the tube body. The limiting cutting knife includes a blade and a handle; the blade has a limiting step that defines the cutting depth, used to limit the cutting depth; the handle has a limiting part, which is the foremost end of the handle, used to limit the maximum cutting depth of the blade, in which case a blade without a limiting step can be used; the depth limiting function of the handle and the depth limiting function of the blade can work together to limit a uniform depth; the limiting depth of the limiting part corresponds to the cutting depth, the limiting width of the blade is used to limit the maximum cutting length, the limiting width of the blade corresponds to the cutting length, and the cutting length corresponds to the circumference of the coarse drainage tube; The booster is a thick-type booster adapted to the thick drainage tube, and the distal end of the booster is a blunt tip that protrudes from the flat end of the insertion end of the thick drainage tube. The limiting incision knife, the booster device, and the thick drainage tube work together to enable the direct insertion of the thick drainage tube into the human body through a skin incision.

5. A drainage device, comprising a drainage tube, a limiting incision knife, a propulsion device, and a long puncture needle; The drainage tube is the drainage tube according to claim 1 or 2; The limiting cutting knife includes a blade and a handle. The handle is provided with a limiting part, which is the foremost end of the handle. The limiting part is used to limit the maximum cutting depth of the blade, and the limiting width of the blade is used to limit the maximum cut length. The booster has a hollow channel that runs through the axis. The long puncture needle can be inserted into the hollow channel to puncture human tissue in order to facilitate the insertion of the drainage tube. The tip of the long puncture needle protrudes from the distal end of the booster device. The limiting cutting knife, the booster device, and the long puncture needle work together to insert the drainage tube into the human body.

6. The drainage device according to claim 3 or 4, characterized in that: The booster device is a booster rod or a booster handle; the booster handle includes a gripping part and a push rod part; the blunt end of the booster rod or the blunt end of the push rod part of the booster handle protrudes from the flat end of the insertion end of the drainage tube or the thick drainage tube by a distance of 0.5mm to 30mm; the maximum outer diameter of the blunt end is equal to the inner diameter of the drainage tube or the thick drainage tube, and the distal end face of the blunt end is used to abut against the flat end face of the insertion end of the drainage tube or the thick drainage tube.

7. The drainage device according to claim 3 or 4, characterized in that: The booster rod or the booster handle has an axially extending hollow channel for the guide wire to pass through or to connect to the syringe.

8. The drainage device according to claim 3 or 4, characterized in that: The distance between the limiting part and the blade edge is 3mm to 10mm.

9. The drainage device according to claim 3 or 4, characterized in that: The cutting length defined by the limiting width of the blade is 0.4 to 0.7 times the outer circumference of the drainage tube or the thick drainage tube.

10. The drainage device according to claim 3, 4 or 5, characterized in that: The drainage device further includes a limiting fastener, which includes a clamp that is closably connected to the booster device. The clamp is used to encircle and fix the connection between the drainage tube or the thick drainage tube and the booster device during the insertion operation, so as to restrict the movement of the drainage tube or the thick drainage tube proximally relative to the booster device.

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