A drainage device for patients with neurogenic bladder

Abstract

This utility model relates to a drainage device for patients with neurogenic bladder, comprising a hollow catheter with a flow channel extending in a spiral direction and recessed radially towards the axis on the outer surface of the catheter. Multiple drug application holes connected to the inner lumen of the catheter are spaced apart along the extension path of the flow channel's bottom wall. The inlet end of each drug application hole is located on the inner wall of the catheter, and the outlet end is located on the bottom wall of the flow channel. The inlet end is offset distally along the axial direction of the catheter relative to the outlet end, forming a reverse inclined channel from the inlet end to the outlet end. This allows the medication injected into the catheter to diffuse along the extension direction of the flow channel after being discharged through the drug application hole. This drainage device, through the combined guiding effect of the spiral flow channel and the inclined drug application holes, allows the medication to diffuse along the spiral trajectory within the flow space formed by the flow channel and the inner wall of the urethra, reducing medication retention in local areas and lowering the risk of infection caused by medication accumulation.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a drainage device for patients with neurogenic bladder. Background Technology

[0002] Neurogenic bladder is a disorder of bladder storage and voiding function caused by damage to the central or peripheral nervous system. Patients with this condition often require long-term catheterization (such as indwelling or intermittent catheterization) for urination management due to loss of voluntary voiding ability. However, catheter-associated urinary tract infection (CAUTI) is its most common complication, with its core risk mechanisms involving two major pathological processes: biofilm formation and retrograde infection. The former refers to bacteria adhering to and colonizing the catheter surface, forming a biofilm barrier through the secretion of a polysaccharide matrix, significantly reducing antibiotic permeability and promoting drug resistance. The latter involves bacteria migrating retrogradely from the urethral orifice along the catheter's outer wall or lumen to the bladder, causing ascending infection.

[0003] In long-term catheterization practice, patients need to change the catheter regularly (silicone catheters are typically changed every 4-6 weeks), and each time the catheter is changed, it needs to remain in place for a relatively long period. To reduce the risk of CAUTI, clinicians can implement local interventions through catheter-attached channels (such as three-lumen catheters): antibiotics, local anesthetics, or antibacterial solutions are injected into the bladder or urethra via the catheter, and potentially contaminated areas around the urethra are regularly flushed. This method removes bacterial colonization through mechanical flushing, inhibits biofilm formation, and reduces the probability of retrograde infection.

[0004] CN210542827U discloses an indwelling urinary catheter for preventing retrograde infection. It achieves high-pressure drug injection through the closed structure of the urethral area and the micropores of the surrounding tube wall, directly flushing the inner wall of the urethra, mechanically removing biofilm and bacteria, and specifically preventing retrograde infection.

[0005] However, this technology has limitations in practical applications. First, the micropores in the catheter wall, due to prolonged direct contact with the urethral inner wall, are easily clogged by urethral secretions and drug deposits, leading to a decrease in flushing fluid throughput and affecting biofilm clearance. Second, the high-pressure drug jet is limited by the urethral anatomy, resulting in uneven drug fluid distribution and difficulty in covering the entire urethra, especially creating flushing blind spots in the distal urethra, potentially leaving residual infection risks. Furthermore, continuous high-pressure impact may mechanically damage the urethral mucosal barrier, actually increasing the risk of bacterial adhesion.

[0006] In view of the above needs, there is an urgent need to design a new type of catheterization device that can ensure that the medication is evenly distributed on the inner wall of the urethra, thereby achieving uniform and rapid drug efficacy and better meeting the treatment needs of patients with neurogenic bladder.

[0007] Furthermore, on the one hand, there are differences in understanding among those skilled in the art; on the other hand, the applicant studied a large number of documents and patents when making this utility model, but due to space limitations, not all details and contents were listed in detail. However, this does not mean that this utility model does not have the features of these prior art. On the contrary, this utility model has all the features of the prior art, and the applicant reserves the right to add relevant prior art to the background art. Utility Model Content

[0008] In view of the shortcomings of the prior art, this application proposes a drainage device, particularly a drainage device for patients with neurogenic bladder, which aims to solve one or more technical problems in the prior art.

[0009] This utility model relates to a drainage device for patients with neurogenic bladder, which includes a hollow catheter. The outer surface of the catheter is provided with a flow channel extending in a spiral direction and recessed radially towards the axis. The bottom wall of the flow channel is provided with a plurality of drug application holes connected to the inner lumen of the catheter at intervals along its extension path. The inlet end of each drug application hole is located on the inner wall of the catheter, and the outlet end is located on the bottom wall of the flow channel. The inlet end is offset distally along the axial direction of the catheter relative to the outlet end, so that the axis of the drug application hole forms a reverse inclined channel from the inlet end to the outlet end, thereby allowing the drug solution injected into the catheter to diffuse along the extension direction of the flow channel after being discharged through the drug application hole.

[0010] The extension path of the spiral flow channel in this drainage device, together with the inclined channel of the administration port, guides the drug solution to diffuse along a spiral trajectory, expanding the coverage area. Simultaneously, the reverse-inclined channel structure allows the drug solution to diffuse progressively from the distal to the proximal end under the influence of flow inertia, avoiding uneven accumulation caused by gravity or pressure concentration. The spaced distribution of administration ports along the bottom wall of the spiral flow channel, combined with the spiral flow space formed by the channel and the inner wall of the urethra, reduces drug retention in localized areas, lowering the risk of infection caused by drug accumulation. Furthermore, the axial offset design of the inlet and outlet ends of the administration ports effectively utilizes the hydrodynamic characteristics of the catheter lumen, reducing the drug jet velocity, enhancing the continuous infiltration effect on the urethral mucosa, and avoiding mechanical irritation to tissues due to excessively high drug flow rates, ultimately optimizing the sustained release of the drug.

[0011] According to a preferred embodiment, axially arranged protrusions are formed between adjacent flow channels. These protrusions are configured to contact and support the urethral wall at their radial height, thereby enclosing a spiral-shaped drug flow cavity between the flow channels and the urethral wall. The radial support of the protrusions allows a gap to be maintained between the catheter and the urethral wall, preventing excessive compression of the tissue by the catheter and ensuring that the spiral flow channels and the urethral wall together form a continuous spiral flow space, guiding the drug solution to diffuse along a predetermined trajectory. Furthermore, the axially arranged protrusions, while providing radial support, also form multiple points of contact along the catheter's axis, enhancing the catheter's stability within the urethra and preventing catheter displacement due to changes in body position or bladder contraction, thus maintaining the integrity of the spiral drug diffusion path.

[0012] According to a preferred embodiment, a plurality of drug delivery channels are arranged axially within the catheter lumen. Drug injection orifices are circumferentially alternately distributed along the flow channel extension direction and are intermittently connected to different drug delivery channels. When flow is obstructed in any drug delivery channel, the medication continues to be delivered through the remaining drug delivery channels and their connected injection orifices, maintaining the continuity of drug diffusion within the flow channel. When flow is restricted in a single drug delivery channel due to blockage or changes in patient position, the remaining channels can still continuously deliver medication through their connected injection orifices, ensuring uninterrupted drug diffusion within the spiral flow channel and avoiding treatment blind spots caused by localized drug delivery failure. The alternating distribution of injection orifices among different drug delivery channels, combined with the extension direction of the spiral flow channel, creates staggered diffusion points for the medication in both the circumferential and axial directions, effectively reducing the potential for drug accumulation or uneven distribution caused by concentrated distribution of injection orifices in a single channel.

[0013] According to a preferred embodiment, the outlet cross-sectional area of ​​different application holes increases from the proximal end to the distal end of the conduit to compensate for the pressure drop as the drug solution flows through the corresponding application hole in the drug supply channel, thereby improving the uniformity of axial drug application. The gradient change in the outlet cross-sectional area can dynamically compensate for the distal pressure drop caused by the increase in the length of the drug supply channel, so that the drug solution flow rate of application holes at different axial positions tends to be consistent under similar driving pressure, avoiding the problems of excessive accumulation of drug solution at the proximal end or insufficient drug application at the distal end.

[0014] According to a preferred embodiment, the pitch of the flow channel gradually decreases along the axial direction of the catheter from the proximal end to the distal end, resulting in a synchronous increase in the axial distribution density of the corresponding drug delivery orifices in the distal region of the catheter. This compensates for the pressure loss along the delivery path of the drug solution through a density gradient. The change in pitch gradient increases the density of the flow channel and drug delivery orifices per unit length at the distal end. The spatial distribution density compensation effect offsets the pressure attenuation along the delivery path of the drug solution during long-distance delivery, ensuring that the drug output from the distal and proximal drug delivery orifices tends to be consistent. The axial gradient design of the helical flow channel density, combined with the helical diffusion path, forms a diffusion coverage intensity that gradually increases from proximal to distal within the urethra. This not only avoids a decrease in drug release due to insufficient pressure at the distal end but also prevents excessive concentration of drug solution at the proximal end.

[0015] According to a preferred embodiment, the cross-sectional area of ​​the outlet end of the drug delivery orifice in the radial section of the catheter is larger than that of the inlet end, forming a funnel-shaped orifice structure that gradually expands along the direction of drug flow, thereby reducing the flow velocity of the drug injection. The gradually expanding orifice structure reduces the flow velocity of the drug as it flows out, causing the high-speed drug to attenuate as it passes through the funnel, reducing the mechanical impact on the urethral mucosa, and simultaneously prolonging the diffusion time of the drug within the spiral flow channel. This synergistic effect of the flow rate regulation mechanism and the spiral diffusion path further enhances the sustained-release effect and penetration depth of the drug in the target area, providing a gentler and more lasting therapeutic effect to the urethral mucosa.

[0016] According to a preferred embodiment, an air bladder is disposed on the surface of the catheter, and the surface of the air bladder is provided with a spiral pattern extending in the same direction as the flow channel. When the air bladder is not inflated, the distal end of the flow channel and the proximal beginning of the spiral pattern are connected to each other to form a complete spiral trajectory on the outer surface of the catheter. Thus, the catheter can convert rotational motion into axial displacement under the guidance of the spiral trajectory. When the air bladder is inflated, the spiral pattern undergoes circumferential displacement as the air bladder expands, thereby improving the fixation stability of the catheter by forming an anchoring contact with the inner wall of the bladder neck.

[0017] When the balloon is not inflated, the complete helical trajectory formed by the connection between the flow channel and the spiral pattern allows the catheter to be smoothly advanced along the helical guide during rotation. This rotation-axial displacement conversion mechanism reduces frictional damage to the urethral mucosa during insertion. Furthermore, the flow channel surface can form intermittent contact surfaces with the urethral wall, further reducing insertion resistance by disrupting continuous adhesion to the urethral mucosa. After the balloon inflates, the circumferential displacement of the spiral pattern creates multi-point anchoring contact with the bladder neck wall. The helically distributed contact pressure enhances the radial fixation force of the catheter, effectively resisting the risk of displacement caused by bladder contraction or changes in body position.

[0018] According to a preferred embodiment, the balloon is connected to the distal end of the inflation channel, which extends axially along the inner lumen of the catheter to the proximal inflation port. When the inflation pressure reaches a threshold, the balloon expands radially to form a urethral fixation structure. When the inflation pressure reaches the set threshold, the balloon expands radially and uniformly to form a conformal contact with the inner wall of the urethra, thus achieving reliable fixation of the catheter in the urethra while avoiding tissue damage caused by local pressure concentration.

[0019] According to a preferred embodiment, the proximal end of the catheter is provided with a urinary catheter port and a drug delivery port. The urinary catheter port communicates with a distal urinary catheter port via a urinary catheter channel extending axially along the inner lumen of the catheter. The drug delivery port connects to the proximal ends of several drug delivery channels via a branched conduit. The urinary catheter port forms a directional drainage path with the distal urinary catheter port through the axially extending urinary catheter channel, ensuring unidirectional drainage of urine under low resistance. The drug delivery port simultaneously connects to multiple drug delivery channels via the branched conduit, enabling the drug solution to be evenly delivered to the target area through multiple independent paths, significantly improving the reliability of the drug delivery process.

[0020] According to a preferred embodiment, the urinary channel and the inflation channel are arranged side-by-side on the inner side of the catheter's central axis, while the drug delivery channel circumferentially surrounds the outer side of the urinary channel and the inflation channel. The urinary channel and the inflation channel are isolated from each other by a partition wall arranged radially along the catheter. This radial partition wall design effectively prevents fluid interaction between the two, avoiding the risk of urine backflow contaminating the inflation system or gas leakage interfering with the urinary path. The layout of the drug delivery channel circumferentially surrounding the urinary channel and the inflation channel fully utilizes the space surrounding the catheter cross-section to achieve multi-channel drug delivery, while radial isolation ensures that the drug diffusion path is not affected by the function of the internal channels. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of a preferred drainage device of this utility model;

[0022] Figure 2 This is a partial structural diagram of a preferred catheter surface according to the present invention;

[0023] Figure 3 This is a schematic diagram of a preferred cross-section of the catheter end of this utility model;

[0024] Figure 4 This is a schematic diagram of the internal structure of a preferred conduit cut radially according to this utility model;

[0025] Figure 5 This is a partial schematic diagram of the preferred liquid flow direction inside the conduit according to this utility model;

[0026] Figure 6 This is a schematic diagram of a preferred connection between the flow channel and the spiral pattern of this utility model;

[0027] Figure 7 This is a schematic diagram showing the relative positional relationship between the spiral pattern and the bladder neck in a preferred configuration of the airbag inflation.

[0028] List of reference numerals

[0029] 100: Catheter; 110: Urinary catheter channel; 111: Urinary catheter interface; 112: Urinary catheter port; 120: Inflation channel; 121: Inflation interface; 130: Drug supply channel; 131: Drug supply interface; 140: Separator; 200: Balloon; 210: Spiral pattern; 300: Flow channel; 301: Protrusion; 310: Drug administration port; 311: Inlet end; 312: Outlet end. Detailed Implementation

[0030] The present invention will now be described in detail with reference to the accompanying drawings.

[0031] Position definition: When the catheter 100 is inserted into place, the end that remains in the bladder cavity is called the distal end, and the end that extends out of the body and connects to the external drainage device is called the proximal end.

[0032] This embodiment relates to a drainage device for patients with neurogenic bladder, such as... Figure 1 As shown, its main structure is a long tubular hollow catheter 100 made of medical-grade silicone or polyurethane material. The outer diameter of the catheter 100 is adapted to the inner diameter of the adult urethra, and the interior is axially continuous to form a hollow lumen. Figure 3 As shown, the inner lumen of catheter 100 is equipped with a urinary catheterization channel 110, an inflation channel 120, and a drug delivery channel 130. Each channel is connected to a urinary catheterization port 111, an inflation port 121, and a drug delivery port 131 located proximally to catheter 100, respectively. Each channel extends axially along the inner lumen of catheter 100. The inflation channel 120 is completely isolated from the urinary catheterization channel 110 by a partition wall 140, and the drug delivery channels 130 are distributed circumferentially outside the urinary catheterization channel 110 or the inflation channel 120. It is worth noting that the number of drug delivery channels 130 can be adjusted to two, three, four, or more according to clinical needs. The circumferentially uniform distribution design ensures radial coverage uniformity for the delivery of antibiotics (such as ciprofloxacin) or lidocaine.

[0033] like Figure 1 , Figure 2 As shown, the outer surface of the conduit 100 is provided with adjacent annular air bladders 200 and spiral flow channels 300 along the axial direction. The flow channel 300 is formed into a U-shaped cross-section recessed structure on the outer surface of the conduit 100 using a spiral trajectory machining process, and the surface of the air bladder 200 is formed with spiral patterns 210 through a molding process. When the air bladder 200 is not inflated, the spiral patterns 210 of the air bladder 200 and the flow channel 300 form a continuous threaded guide structure in space, that is, both have the same spiral direction, and the distal end of the flow channel 300 is connected to the proximal end of the spiral patterns 210 (e.g., ...). Figure 6(As shown). This structural design allows the catheter 100 to be advanced by rotation during insertion into the patient's body. The rotation disperses the insertion pressure, avoiding mucosal damage caused by localized stress concentration, making it particularly suitable for patients with urethral stricture or curvature. Simultaneously, the spiral grooves 210 disrupt the vacuum adhesion effect between the smooth surface of the catheter 100 and the moist urethral mucosa, effectively reducing insertion resistance. In clinical application, the spiral flow channel 300 is located in the urethra, while the balloon 200 is partially located within the bladder. In its uninflated state, the spiral grooves 210 form a motion-guiding structure with the flow channel 300. Once the balloon 200 is inflated and fixed, as... Figure 7 As shown, the anchoring contact points of the spiral pattern 210 are evenly distributed around the bladder neck, avoiding local stress concentration. The dynamic coupling design of the airbag 200 enables a single component to have the dual functions of rotational propulsion and fixed anchoring.

[0034] like Figure 4 , Figure 5 As shown, the flow channel 300 extends axially along the outer surface of the conduit 100 in a spiral trajectory, with drug application holes 310 spaced apart on its bottom wall. The inlet end 311 of the drug application hole 310 is located on the circumference of the drug supply channel 130 in the inner cavity of the conduit 100, while the outlet end 312 is located at the center of the bottom wall of the flow channel 300, thus forming a channel for drug liquid ejection between the drug supply channel 130 and the flow channel 300. The inlet end 311 is offset towards the distal end of the conduit 100 relative to the outlet end 312, so that the drug application hole 310 forms an inclined channel opposite to the direction of drug liquid flow in the drug supply channel 130. Preferably, in the axial section, the axis of the application hole 310 forms an angle of 50° to 70° with the axis of the catheter 100. This angle causes the axis of the application hole 310 to be tilted in the opposite direction to the extension direction of the flow channel 300 in the cross section perpendicular to the axis of the catheter 100. This creates a reverse flow splitting effect between the mainstream direction of the drug solution in the inner cavity of the catheter 100 and the ejection direction of the application hole 310. This reverse flow splitting drives the drug solution to form a circumferential diffusion in the flow channel 300, thereby improving the filling uniformity of the spiral drug solution flow channel 300 and reducing the local impact pressure on the inner wall of the urethra.

[0035] Preferably, such as Figure 4 , Figure 5As shown, the drug delivery orifice 310 adopts a funnel-shaped orifice structure design, with its outlet end 312 having a larger cross-sectional area than its inlet end 311, forming a gradually expanding channel along the drug flow direction. This design reduces the risk of drug crystallization blockage and improves drug diffusion efficiency. On the outer surface of the catheter 100, axially arranged protrusions 301 are present between adjacent spiral channels 300. The top arc surface of these protrusions is higher than the bottom wall of the channel 300, forming contact support points with the urethral wall. This multi-point support structure reduces the contact area between the catheter 100 and the mucosa, lowering frictional resistance and protecting the urethral mucosa. Specifically, the pitch of adjacent channels 300 is larger in the proximal region of the catheter 100 and gradually decreases in the distal region, significantly increasing the density of channels 300 per unit length in the distal region. This simultaneously increases the axial distribution density of the drug delivery orifice 310, compensating for pressure loss along the drug delivery process and enhancing drug diffusion in the distal region. In further design optimization, the cross-sectional area of ​​the outlet end 312 of each application hole 310 increases gradually from the near end to the far end. By adjusting the cross-sectional area of ​​the orifice, the pressure attenuation of the liquid in the drug supply channel 130 when it flows through different positions is compensated, and finally the uniform distribution of axial application is achieved.

[0036] During drug delivery, the drug solution enters several drug delivery channels 130 through the drug delivery interface 131 located near the proximal end of the catheter 100, and is then introduced into the flow channel 300 via the reverse-inclined application holes 310. The flared structure at the outlet end 312 reduces the drug flow rate, causing it to diffuse along the spiral direction of the flow channel 300. When a drug delivery channel 130 becomes blocked, the remaining drug delivery channels 130 maintain drug output through the alternately distributed application holes 310, ensuring the continuity of the spiral diffusion path. The urinary catheter channel 110 independently drains bladder urine, the inflation channel 120 controls the inflation state of the balloon 200, and the drug delivery channels 130 achieve multi-path redundant drug delivery through branching tubing.

[0037] During drug diffusion, the counter-sloping application port 310 guides the drug flow direction to align with the spiral extension trajectory of the flow channel 300. The flared outlet end 312 structure ensures that the drug flowing from the supply channel 130 forms a laminar flow. Combined with the guiding effect of the spiral flow channel 300, the drug can form a drug film that continuously wets the urethral wall. This counter-sloping design also prevents the drug from directly impacting the urethral wall vertically, avoiding mechanical damage. The protrusion 301, while maintaining the position of the catheter 100 within the urethra, forms a spiral flow cavity with the urethral wall, limiting the radial escape of the drug.

[0038] like Figure 3As shown, the urinary catheter channel 110 is located on the central axis of the catheter 100, extending from the proximal catheter port 111 to the distal catheter port 112. An inflation channel 120 is parallel to the upper side of the urinary catheter channel 110, connecting proximally to the inflation port 121 and distally to the inner cavity of the balloon 200. The two are physically isolated by a radially arranged partition wall 140. Two drug delivery channels 130 are distributed around the urinary catheter channel 110 and the inflation channel 120. The proximal ends of each drug delivery channel 130 are connected to the drug delivery port 131 via branching tubing. The drug delivery port 310 alternately connects to different drug delivery channels 130 along the spiral direction of the flow channel 300. For example, within the same spiral loop, the first drug delivery port 310 connects to the first drug delivery channel 130, and the second connects to the second drug delivery channel 130, forming a periodic alternating distribution pattern. This multi-channel design ensures good drug flow regardless of the patient's posture. When the flow of a single drug delivery channel 130 is restricted due to blockage or changes in patient position, the remaining channels can still continuously deliver medication through their connected drug delivery orifices 310, ensuring that the drug diffusion path within the spiral flow channel 300 is uninterrupted and avoiding treatment blind spots caused by local drug delivery failure. The alternating distribution of drug delivery orifices 310 among different drug delivery channels 130, combined with the extension direction of the spiral flow channel 300, creates staggered diffusion points for the medication in both the circumferential and axial directions, effectively reducing the problems of medication superposition or uneven distribution that may be caused by the concentrated distribution of drug delivery orifices 310 in a single channel.

[0039] During operation, the rotational motion of the proximal end of catheter 100 is converted into axial propulsion through a helical trajectory, and the dynamic contact between the protrusion 301 and the urethral wall reduces frictional damage. After the balloon 200 inflates, the circumferential displacement of the helical pattern 210 matches its material ductility, ensuring a balance between anchoring force and tissue safety. When the medication is delivered through the drug delivery channel 130, the cross-sectional area of ​​the proximal application port 310 outlet end 312 is smaller, gradually increasing towards the distal end, forming a pressure compensation gradient. Combined with the density gradient of the flow channel 300 pitch, this maintains the uniformity of the axial distribution of the medication.

[0040] It should be noted that the above specific embodiments are exemplary. Those skilled in the art can devise various solutions inspired by the disclosure of this utility model, and these solutions all fall within the scope of this utility model and its protection scope. Those skilled in the art should understand that this utility model specification and its drawings are illustrative and do not constitute a limitation on the claims. The protection scope of this utility model is defined by the claims and their equivalents. Throughout the text, features introduced by "preferred" are merely optional and should not be construed as mandatory. Therefore, the applicant reserves the right to abandon or delete relevant preferred features at any time.

Claims

1. A drainage device for patients with neurogenic bladder, comprising a hollow catheter (100), characterized in that, The outer surface of the conduit (100) is provided with a flow channel (300) extending in a spiral direction and recessed radially toward the axis. The bottom wall of the flow channel (300) is provided with a plurality of drug application holes (310) connected to the inner cavity of the conduit (100) at intervals along its extension path. The inlet end (311) of each drug application hole (310) is located on the inner wall of the conduit (100), and the outlet end (312) is located on the bottom wall of the flow channel (300). The inlet end (311) is offset distally along the axial direction of the conduit (100) relative to the outlet end (312), so that the orifice axis of the drug application hole (310) forms a reverse inclined channel from the inlet end (311) to the outlet end (312), thereby enabling the drug solution injected into the conduit (100) to diffuse along the extension direction of the flow channel (300) after being discharged through the drug application hole (310).

2. The drainage device of claim 1, wherein, Axially arranged protrusions (301) are formed between adjacent flow channels (300), the protrusions (301) being configured to form contact support with the inner wall of the urethra in their radial height, so that the flow channels (300) and the inner wall of the urethra enclose a spiral flow cavity for the drug solution.

3. The drainage device of claim 1, wherein, The inner cavity of the catheter (100) is provided with a plurality of drug supply channels (130) along the axial direction. The drug application holes (310) are circumferentially alternately distributed along the extension direction of the flow channel (300) and are connected to different drug supply channels (130) at intervals. When the flow in any drug supply channel (130) is obstructed, the drug solution is continuously output through the remaining drug supply channels (130) and the connected application holes (310), maintaining the diffusion continuity of the drug solution in the flow channel (300).

4. The drainage device according to claim 3, characterized in that, The cross-sectional area of ​​the outlet end (312) of the different application holes (310) increases from the proximal end to the distal end of the conduit (100) to compensate for the pressure drop when the liquid in the drug supply channel (130) flows through the corresponding application hole (310), thereby improving the uniformity of axial drug application.

5. The drainage device according to claim 1, characterized in that, The pitch of the flow channel (300) gradually decreases from the proximal end to the distal end along the axial direction of the conduit (100), thereby synchronously increasing the distribution density of the drug application holes (310) corresponding to the distal region of the conduit (100) along the axial direction, thereby compensating for the pressure loss along the delivery of the drug solution through the density gradient.

6. The drainage device according to claim 1, characterized in that, The cross-sectional area of ​​the outlet end (312) of the drug application hole (310) on the radial section of the conduit (100) is larger than that of the inlet end (311) to form a funnel-shaped orifice structure that gradually expands along the direction of drug flow, thereby reducing the flow rate of drug injection.

7. The drainage device according to claim 1, characterized in that, An air bladder (200) is disposed on the surface of the conduit (100), and the surface of the air bladder (200) is provided with a spiral pattern (210) extending in the same direction as the flow channel (300), wherein, When the airbag (200) is not inflated, the distal end of the flow channel (300) and the proximal start of the spiral pattern (210) are connected to each other to form a complete spiral trajectory on the outer surface of the conduit (100), thereby the conduit (100) can convert rotational motion into axial displacement under the guidance of the spiral trajectory. When the balloon (200) inflates, the spiral pattern (210) undergoes circumferential displacement as the balloon (200) expands, thereby improving the fixation stability of the catheter (100) by forming an anchoring contact with the inner wall of the bladder neck.

8. The drainage device according to claim 7, characterized in that, The balloon (200) is connected to the distal end of the inflation channel (120), which extends axially along the inner lumen of the catheter (100) to the proximal inflation port (121). When the inflation pressure reaches the threshold, the balloon (200) forms a urethral fixation structure by radial expansion.

9. The drainage device according to claim 3, characterized in that, The catheter (100) is provided with a urinary catheter port (111) and a drug delivery port (131) at its proximal end. The urinary catheter port (111) is connected to the distal urinary catheter port (112) through a urinary catheter channel (110) extending axially along the inner lumen of the catheter (100). The drug delivery port (131) is connected to the proximal ends of several drug delivery channels (130) through a branched conduit.

10. The drainage device according to claim 9, characterized in that, The urinary catheter channel (110) and the inflation channel (120) are arranged side by side on the inner side of the central axis of the catheter (100), and the drug delivery channel (130) surrounds the outer side of the urinary catheter channel (110) and the inflation channel (120). The urinary catheter channel (110) and the inflation channel (120) are isolated by a partition wall (140) arranged radially along the catheter (100).

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