WO2020146454A1 - Advanced drainage catheter - Google Patents

Abstract

The present invention relates to a percutaneous drainage catheter having a plurality of lumens that allows continuous or frequent flushing of collection fluid and drainage lumen, improving drainage of thick material.

Description

TITLE

ADVANCED DRAINAGE CATHETER

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 62/789,558, filed January 8, 2019, the contents of which are incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

Percutaneous drainage of fluid collections inside the body is currently achieved by placement of a percutaneous drainage catheter. This is typically a silicone or plastic tube which has a distal pigtail and numerous side holes which are positioned within the collection to be drained, and a proximal end hole that is attached to a drainage bag or suction to remove the fluid. This design has remained essentially the same for decades, with minimal improvement in the technology. These drainage catheters are quite effective at removing simple or thin fluid, but are limited for removal of thick fluid, tenacious material, or solid chunks of tissue. The catheter can be easily clogged by such materials, or the material may be too thick to pass into the catheter at all; this results in slow or ineffectual drainage of many collections, resulting in increased morbidity, increased length of stay, and the need for multiple drainage catheter exchanges and upsizes (or even surgical evacuation in failed cases).

To keep drainage catheters patent and prevent clogging, regular flushing is typically performed. This is often done 2-3 times per day, usually by a nurse, and involves detaching the proximal end of the catheter from the drainage bag or suction, attaching a flush syringe, injecting saline flush solution through the catheter, and re-attaching the drainage bag or suction. It is a rather laborious process which requires several attachments and

detachments, and thus is usually only performed a few times per day. Because of this, drains often become clogged in the interim between flushes. The flushing of the catheter also functions to loosen and hydrate the material within the collection, to aid in its drainage.

However, since flushing is only done a few times per day, the material often remains tenacious and difficult to drain. Thus, there is a need in the art for an improved percutaneous drainage system that a) allows drainage of thick fluid, tenacious material, or solid chunks of tissue without clogging, b) prevents or minimizes the need to frequently disconnect the drainage catheter from the drainage bag or suction in order to flush the catheter, and c) improves the speed and smoothness of drainage by allowing air in for continuous atmospheric irrigation as fluid drains.

SUMMARY OF THE INVENTION

In one aspect, the present invention relates to a catheter comprising: an elongate tube having an open proximal end, an open distal end, a length therebetween, and a drainage lumen within the tube extending between the proximal and distal ends; a plurality of holes positioned on a wall of the elongate tube, each of the holes fluidly connected to the drainage lumen; and at least one flush lumen positioned parallel to the tube, the at least one flush lumen having a plurality of inner and outer flush holes, wherein the inner flush holes fluidly connect the flush lumen to the drainage lumen.

In one embodiment, the distal end of the elongate tube comprises a curved region. In one embodiment, at least one of the plurality of holes of the drainage lumen resides within the curved region. In one embodiment, at least one of the plurality of flush holes of the at least one flush lumen resides within the curved region. In one

embodiment, the plurality of holes of the drainage lumen is evenly spaced over the length of the elongate tube. In one embodiment, the plurality of holes of the drainage lumen are larger than the plurality of flush holes. In one embodiment, the drainage lumen has a diameter that is greater than a diameter of the at least one flush lumen. In one embodiment, the plurality of inner and outer flush holes is evenly spaced over the length of the elongate tube. In one embodiment, the distal end is positionable in a subject’s body cavity. In one embodiment, at least a portion of the length of the elongate tube is reinforced with wire. In one embodiment, a connector is attached to the proximal end of the drainage lumen, the at least one flush lumen, or both. In one embodiment, the connector is selected from the group consisting of: a luer lock, a tube fitting, a threaded connector, and a barbed connector. In one embodiment, at least one of the flush lumens is positioned within a wall of the elongate tube. In one embodiment, the catheter further comprises a control unit comprising: a flush pump fluidly connected to the proximal end of the flush lumen at a first end and fluidly connected to a flush reservoir at an opposing second end, wherein the flush pump is configurable to pump flushing fluid from the flush reservoir into the flush lumen; a suction pump fluidly connected to the proximal end of the drainage lumen at a first end and fluidly connected to a drainage reservoir at an opposing second end, wherein the suction pump is configurable to apply a suction to the drainage lumen in order to draw fluid into the drainage reservoir; a weigh scale positioned beneath each of the flush reservoir and drainage reservoir; and a computer platform configured to monitor and control the flush pump and the suction pump.

In one embodiment, the computer platform measures decreases in a volume of fluid in the flush reservoir and increases in a volume of fluid in the drainage reservoir using the weigh scales. In one embodiment, the computer platform is configured to provide an alert if the decrease in the volume of fluid in the flush reservoir exceeds the increase in the volume of fluid in the drainage reservoir. In one embodiment, the computer platform is configured to decrease or cease a flow of flushing fluid from the flush reservoir if the decrease in the volume of fluid in the flush reservoir exceeds the increase in the volume of fluid in the drainage reservoir.

In one embodiment, the control unit further comprises a three-way stopcock, wherein the stopcock comprises: a tubular body having a first tube section, a second tube section, and a third tube section, wherein each of the first, second, and third tube sections comprises a lumen and are fluidly connected at a first end to a central connector and terminate in an opening at a second end opposite to the first end; and a central component comprising a circumference that is slightly less than a circumference of the central connector, such that central element may be inserted within the central connector with minimal tolerance, and wherein the central component comprises a first open side, a second open side, a third open side, and a closed side; wherein the second end of the first tube section is connected to the proximal end of a standard catheter;

wherein the second end of the second tube section is fluidly connected to the flush pump; and wherein the second end of the third tube section is fluidly connected to the suction pump. In one embodiment, the stopcock comprises: a drain mode, wherein the central component produces a patent channel from the drainage lumen through the first open side and the third open side into a drainage reservoir; and a flush mode, wherein the central component produces a patent channel from a flush reservoir through the first open side and the second open side into a flush lumen.

In another aspect, the present invention relates to a method for removing fluid from a body cavity in a subject, comprising: providing a catheter having a drainage lumen and at least one flush lumen, a plurality of outer holes draining out of each of the lumens, a plurality of inner holes fluidly connecting the drainage lumen to the at least one flush lumen, and a curved region; inserting a stylet into a lumen of the catheter to temporarily straighten the curved region; positioning the curved region inside a body cavity; removing the stylet from the catheter to restore the curvature of the curved region; passing a liquid through the at least one flush lumen to flush the body cavity; and draining the liquid from the body cavity through the drainage lumen.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description of embodiments of the invention will be better understood when read in conjunction with the appended drawings. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities of the embodiments shown in the drawings.

Fig. 1 depicts a schematic of an exemplary advanced drainage catheter.

Fig. 2 depicts a schematic of an exemplary drainage catheter tip in a “pigtail” loop configuration with small flush holes in outer and inner margin of the flush lumen.

Fig. 3 depicts a cross-sectional view of a section of an exemplary advanced drainage catheter.

Fig. 4 depicts a cutaway view of a longitudinal section of an exemplary advanced drainage catheter.

Fig. 5 depicts a block diagram of an exemplary control unit. Fig. 6 depicts an exemplary drainage catheter connection to the control unit. Fig. 7 depicts an exemplary control unit connected to a drainage catheter via a three way connector.

Fig. 8 depicts a side view of a three way connector in drain mode.

Fig. 9 depicts a side view of a three way connector in flush mode.

Fig. 10 is a flowchart depicting an exemplary method of removing fluid from a body cavity using a drainage catheter of the present invention.

Fig. 11 is a photograph of a 28-Fr prototype showing a main curved drainage catheter (black arrow) with an embedded 4-Fr flush catheter (white arrow) containing inner- and outer-facing 30-gauge flush holes (not visible at IX magnification).

Fig. 12A depicts an illustration of an experimental setup for high gravity (hi) and low gravity (hi) conditions. Fluid drains into open container in which mass and time are recorded. Note catheter length and initial reservoir volume (Vi) are constant. Fig. 12 B depicts a photograph of an experimental setup for the low gravity condition, which features the compressible fluid reservoir bag (black dashed arrow), large-bore protype catheter (black solid arrow), small-bore intra-/extra-luminal flush port (white solid arrow), and mass collection system with electronic balance (white dashed arrow).

Fig. 13 A and Fig. 13B depict the results of serous fluid model drainage rates for 18-28 Fr control catheters at 8” height. (Fig. 13 A) Drainage rates for catheters with luer-lock attachment demonstrate no distinguishable difference despite varying catheter sizes. (Fig. 13B) Drainage rates for the same four catheters draining freely into open container demonstrate expected increase in flow with increasing lumen diameter as predicted by Poiseuille’s equation.

Fig. 14A and Fig. 14B depict average flow rates and cumulative drainage for 20 French trials in an in vitro abscess/purulent fluid model (liquefied yogurt) at 8” drainage height.

Fig. 15A and Fig. 15B depict average flow rates and cumulative drainage for 28 French trials in an in vitro abscess/purulent fluid model (liquefied yogurt) at 8” drainage height.

Fig. 16A and Fig. 16B depict average flow rates and cumulative drainage for 28 French trials in a pancreatic/necrotic fluid model (20% fine oats + 20% oat fiber) at 8” drainage height. Fig. 17A and Fig. 17B depict average flow rates and cumulative drainage for 28 French trials in an in vitro hematoma model (bovine whole blood) at 8” drainage height. DETAILED DESCRIPTION

It is to be understood that the figures and descriptions of the present invention have been simplified to illustrate elements that are relevant for a clear understanding of the present invention, while eliminating, for the purpose of clarity, many other elements found in the field of drainage catheters. Those of ordinary skill in the art may recognize that other elements and/or steps are desirable and/or required in implementing the present invention. However, because such elements and steps are well known in the art, and because they do not facilitate a better understanding of the present invention, a discussion of such elements and steps is not provided herein. The disclosure herein is directed to all such variations and modifications to such elements and methods known to those skilled in the art.

Definitions

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although any methods and materials similar or equivalent to those described herein can be used in the practice for testing of the present invention, exemplary materials and methods are described herein. In describing and claiming the present invention, the following terminology will be used.

It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting.

The articles“a” and“an” are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example,“an element” means one element or more than one element.

“About” as used herein when referring to a measurable value such as an amount, a temporal duration, and the like, is meant to encompass variations of ±20%, ±10%, ±5%, ±1%, or ±0.1% from the specified value, as such variations are appropriate. The terms“patient,”“subject,”“individual,” and the like are used interchangeably herein, and refer to any animal amenable to the systems, devices, and methods described herein. The patient, subject or individual may be a mammal, and in some instances, a human.

Ranges: throughout this disclosure, various aspects of the invention can be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as from 1 to 6 should be considered to have specifically disclosed subranges such as from 1 to 3, from

I to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numbers within that range, for example, 1, 2, 2.7, 3, 4, 5, 5.3, and 6. This applies regardless of the breadth of the range.

Advanced Drainage Catheters

The present invention relates in part to percutaneous catheters having a plurality of lumens that allows drainage of thick fluid, tenacious material, or solid chunks of tissue without clogging of the catheter.

Referring now to Fig. 1, an exemplary ulti -lu en drainage catheter 10 of the present invention is shown. Catheter 10 comprises a flexible, elongate tube member

I I having a length aligned along a longitudinal axis and a distal end 13. In one embodiment, tubular member 11 comprises a draining lumen 14 connecting an open proximal end 16 to an open distal tip 24 at distal end 13. Flush lumen 18 is positioned adjacent to draining lumen 14 and also extends between proximal end 16 and distal end 13. In some embodiments, a connector 20 is provided at the proximal end of drainage lumen 14, flush lumen 18, or both. Connector 20 can be any suitable mechanism known in the art configured to fluidly join tubes end-to-end, including but not limited to luer locks, tube fittings, threaded connectors, barbed connectors, and the like. In some embodiments, connector 20 can be closed with a cap for reversibly sealing an associated lumen. The caps can be closed to prevent foreign objects from entering or exiting, and opened to permit entry and exit of flushing fluids, drained fluids, and the like. In some embodiments, the caps can be left open to the atmosphere for ventilation and for passive draining by gravity, which vents the lumens to atmospheric pressure for continuous irrigation and reduces the risk of vacuum formation within a body cavity. In various embodiments, proximal end 16 and connector 20 (and accompanying connectors and tubing) can have bores or diameters that are equal to or larger than drainage lumen 14 and flush lumen 18 to facilitate drainage by reducing occlusion and increasing flow rates.

In some embodiments, as shown in Fig. 1, distal end 13 comprises at least one preformed curve represented by curved regions 12 to inhibit unintended withdrawal or displacement of catheter 10. Curved regions 12 can have any curved configuration, including but not limited to loops, bends, hooks, spirals, twists, pigtail curves, Judkins style curves, Amplatz style curves, SOS style curves, cobra style curves, Simmons style curves, Bernstein style curves, and the like in a primary curve, secondary curve, tertiary curve, or more. Curved regions 12 may be pre-formed, such as by heat setting. In some embodiments, at least a portion of the length of catheter 10 comprises an embedded wire 26. The reinforcement provided by wire 26 enables catheter 10 to be suitably advanced into position within a subject and improves stability once positioned. Wire 26 can also comprise a preformed curvature defining the shape of curved regions 12. Accordingly, catheter 10 may include portions or regions having the desired stiffness, rigidity or flexibility necessary for proper insertion into the subject and subsequent functionality. In some embodiments, curved regions 12 are at least partially flexible, such that curved regions 12 may be temporarily straightened using a stylet, or such that curved regions 12 may be advanced over a guidewire. Stylets, guidewires, and the like can be routed through any of the lumens of catheter 10.

In some embodiments, curved regions 12 can be manipulated using an external device such as a sleeve or tube body that can be slidably engaged to catheter 10. The sleeve or tube body of the external device can have an inner diameter as large or larger than the outer diameter of tubular member 11, allowing the external device to slide along the length of catheter tubular member 11. For purposes of this disclosure, one of ordinary skill in the art may appreciate that a cannula or any other apparatus may likewise be used to substantially perform the same objective. Curved regions 12 represent an unexpected finding that by having a set curve within the parameters set forth herein, the catheters of the present invention significantly reduce damage to the body upon insertion and placement and create an improved draining and return flow of fluid through the respective lumens due to the fact that the catheters are able to sit within the body cavity in a relaxed state without exerting unnecessary pressure upon tissue or requiring a rigid guidewire or stylet to remain in place.

Referring now to Fig. 2 through Fig. 4, the lumens of catheter 10 are described in detail. As described elsewhere herein, in some embodiments catheter 10 comprises drainage lumen 14 and flush lumen 18. Drainage lumen 14 is configured to drain fluid from a subject. Flush lumen 18 is configured to allow continuous or intermittent flushing of a body cavity and drainage lumen 14 to prevent clogging and improve drainage. As shown in Fig. 2, drainage lumen 14 and flush lumen 18 are affixed in a parallel fashion with each other. In some embodiments, catheter 10 can comprise a plurality of flush lumens 18. In some embodiments, flush lumen 18 is incorporated inside the wall of drainage lumen 14 (Fig. 3). In some embodiments, flush lumen 18 is positioned outside the wall of drainage lumen 14.

As shown in Fig. 2, in some embodiments, drainage lumen 14 comprises a plurality of drainage holes 22 having large diameters for draining fluids and masses of material from a body cavity. In some embodiments, each of the drainage holes 22 has a diameter between about 2 mm to about 6 mm. In some embodiments, drainage holes 22 are sized relative to a diameter of drainage lumen 14. For example, drainage holes 22 can be sized to match the diameter of drainage lumen 14, or to exceed the diameter of drainage lumen 14. The plurality of drainage holes 22 can be positioned at any location along the length of tubular member 11 near distal end 13, with spacing between drainage holes 22 between about 5 mm to about 15 mm. In one embodiment, spacing between drainage holes 22 is about 10 mm. In some embodiments, the plurality of drainage holes 22 are located entirely within curved regions 12. In one embodiment, the plurality of drainage holes 22 are located entirely along tubular member 11. In one embodiment, more than 50% of the plurality of drainage holes 22 are located in curved regions 12. In one embodiment, more than 50% of the plurality of drainage holes 22 are located on tubular member 11. In some embodiments, drainage holes 22 can be variably spaced apart. In one embodiment, the plurality of drainage holes 22 may be spaced close together at distal end 13 and farther apart closer to proximal end 16, or vice versa. This configuration may facilitate the interfacing of the plurality of drainage holes 22 with different types of tissue encountered at various parts of catheter 10. Additionally, the angles of the plurality of drainage holes 22 relative to the longitudinal axis of the catheter 10 may also vary. The plurality of drainage holes 22 themselves may vary in cross- sectional geometry (i.e., semi-circular, triangular, trapezoid) and may be placed at one or more discrete locations along catheter 10.

Flush lumen 18 comprises a plurality of outer flush holes 28 and a plurality of inner flush holes 30. Outer flush holes 28 allow the administration of fluid into a body cavity to wash the area and dislodge unwanted material. Inner flush holes 30 are fluidly connected to drainage lumen 14 and help maintain potency of drainage lumen 14. The plurality of outer flush holes 28 and plurality of inner flush holes 30 can have any suitable diameter, such as between about 0.2 mm to about 1.0 mm. The plurality of inner and outer flush holes 30 and 28 can be positioned along the length of tubular member 11 near distal end 13. Inner and outer flush holes 30 and 28 can each be spaced apart by any suitable distance, such as between about 2 mm to about 10 mm, or about 5 mm. In one embodiment, the plurality of inner and outer flush holes 30 and 28 are located entirely within curved regions 12. In one embodiment, the plurality of inner and outer flush holes 30 and 28 are located entirely along tubular member 11. In one embodiment, more than 50% of the plurality of inner and outer flush holes 30 and 28 are located at distal end 13. In one embodiment, more than 50% of the plurality of inner and outer flush holes 30 and 28 are located on tubular member 11. The plurality of inner and outer flush holes 30 and 28 may vary in cross-sectional geometry (i.e., semi-circular, triangular, trapezoid) and may be placed at one or more discrete locations along catheter 10.

In some embodiments, catheter 10 can be modified to have different flushing regions, where in some regions all flush holes are directed towards drainage lumen 14 and in other regions while in other regions flush holes are direct outwards and inwards as described above. In this configuration, regions having flush holes that are directed outwards and inwards are capable of flushing drainage lumen 14 and a body cavity, while regions having all flush holes directed inwards only flush drainage lumen 14.

In some embodiments, catheter 10 can be modified to direct all flush holes towards drainage lumen 14. Certain catheter applications are used primarily in feeding and administering medication, wherein liquefied tube feeds and medications are instilled through a tube to the stomach or small intestine. In this configuration, drainage lumen 14 administers feed solutions, similar to gastrostomy tubes, gastrojejunostomy tubes, and jejunostomy tubes. These tubes frequently become occluded due to build-up of thick fluid or debris and often require resource-intensive procedures to exchange occluded tubes for new tubes. By directing all flush holes towards drainage lumen 14, flushing fluids can be used to reduce build-up of debris and help maintain tube patency.

Referring now to Fig. 3, a cross-sectional view of a section of catheter 10 is depicted in detail. In the depicted embodiment, flush lumen 18 is incorporated within the wall of tube member 11. Outer flush holes 28 in the outer margin of the wall of tube member 11 are shown fluidly connecting flush lumen 18 to the exterior of catheter 10. Outer flush holes 28 are thereby configured to face towards the interior of a body cavity. A cleansing fluid such as a saline solution can thereby be injected into flush lumen 18 and directed into a body cavity by way of outer flush holes 28 to wash the body cavity, dislodge unwanted material, and dilute cavity fluids to ease drainage.

Referring now to Fig. 4, a cutaway view of a longitudinal section of catheter 10 is depicted. In the depicted embodiment, inner flush holes 30 are positioned in the inner margin of tube member 11 and are shown fluidly connecting flush lumen 18 to drainage lumen 14. Inner flush holes 30 are thereby configured to face towards the interior of drainage lumen 14. A cleansing fluid such as a saline solution can thereby be injected into flush lumen 18 and directed into drainage lumen 14 by way of inner flush holes 30 to remove any built up or clogged material within drainage lumen 14.

It should be appreciated that the catheters of the present invention are not limited to any particular dimensions of length, gauge or other sizing characteristic.

Accordingly, catheter 10 can be any size suitable for the dimensions or requirements of a subject or procedure. For example, in certain embodiments catheter 10 can have a tubular member 11 with typical lengths between about 15 cm to about 50 cm. In other embodiments, the dimensions of catheter 10 can be defined by lengths of drainage regions, such as a region of catheter 10 with drainage holes 22 having a length between about 5 cm to about 15 cm. In other embodiments, the dimensions of catheter 10 can be further defined by the distance between the position of the most distal drainage hole 22 and the position of proximal end 16, which can be between about 20 cm to about 60 cm. In one embodiment, the dimensions of catheter 10 can be further defined by the diameter of open distal tip 24, which can be between about 0.018 inch to about 0.038 inch or about 0.5 mm to about 1 mm. In one embodiment, the dimensions of catheter 10 can be further defined by the diameter of the proximal opening, which can be between about 6 French to about 36 French (about 2 mm to about 12 mm) or to 40 French or greater.

As would be understood by persons skilled in the art, the length and diameter of the catheters of the present invention and the location of the various holes can be varied to optimize the drainage of fluid from subjects. For example, in one

embodiment, the diameter of drainage lumen 14 in catheter 10 can be sized between about 12 French to about 40 French catheter scale to allow large tissue pieces or thick fluid to pass without clogging.

The catheters of the present invention may be constructed from any materials commonly used in the art, and particularly in catheters associated with percutaneous drainage for insertion into a subject. For example, catheter 10 may be constructed of a thermoplastic polymer, including but not limited to polyurethane, ethyl vinyl acetate (EVA), polyether block amide elastomer, polypropylene, or polyolefin elastomers. Catheter 10 can also be constructed of a thermoset plastic such as silicone. Curved regions 12 may likewise be flexible and may be constructed of a different material than the remainder of catheter 10.

It should be understood that the several features of the drainage catheters of the present invention can be rearranged or modified to accommodate different orientations and configurations. As will be appreciated by those skilled in the art, a variety of types and configurations of catheters can be utilized for draining bodily fluids from a subject without departing from the scope and spirit of the present invention. In some embodiments, the drainage catheters can be adapted to be positioned adjacent to an organ or in the vasculature of a patient. In some embodiments, the drainage catheters can be routed through vasculature, such as in tunneled and non-tunneled catheters.

In various embodiments, the drainage catheters can be adapted to drain any suitable body cavity. Non-limiting examples include biliary drainage, pleural drainage, peritoneal drainage, kidney drainage, bladder drainage, and gallbladder drainage. The drainage catheters can be used for external drainage, wherein fluids are drained out of a subject, or for internal-external drainage, wherein fluids are drained out of a subject or into a different location in a subject (such as the small intestine). In any use case, the drainage catheters are configured to provide a flushing fluid to reduce viscosity (e.g., thick or inspissated bile), break up debris (e.g., fibrinous material such as empyemas and blood clots), and to rinse and clean.

In some embodiments, a kit according to the present invention may include, in addition to the components discussed above, additional tubing, sterile gloves, sterilization pads, additional members configured to be inserted into the drainage catheter such as diagnostic testing implements or devices, structural support elements, or other devices and implements used in conjunction with drainage catheters.

Control Unit

In another aspect, the present invention further comprises a control unit 100. Control unit 100 allows two way communication to measure the amount of flush solution input and measure the amount of drainage fluid output. In one embodiment, control unit 100 is configured to remotely control drainage catheter 10. In one embodiment, control unit 100 is configured to allow remote monitoring of drainage catheter 10 to increase efficacy.

Referring now to Fig. 5, a block diagram of an exemplary control unit 100 is depicted. Control unit 100 comprises a flush pump 102, a suction pump 104, a drainage reservoir 106, a flush reservoir 108, and a computer platform.

Referring now to Fig. 6, an exemplary control unit 100 is shown in connection with an exemplary catheter 10. Flush pump 102 is fluidly connected to proximal end 16 of flush lumen 18 at a first end and fluidly connected to flush reservoir 108 at a second end. Flush pump 102 pumps fluid from flush reservoir 108 into flush lumen 18. In one embodiment, flush pump 102 can be any medical device configured to deliver a steady stream of fluids to a body cavity. In one embodiment, volume and frequency of flush pump 102 can be controlled by the computer platform. In one embodiment, flush pump 102 is fluidly attached to flush lumen 18 through connector 20. In one embodiment, flush pump 102 is fluidly connected to proximal end 16 of flush lumen 18 through valve 110. In one embodiment, valve 110 may be provided with a switching mechanism to allow valve 110 to be switched between on and off positions.

Suction pump 104 is fluidly connected to proximal end 16 of drainage lumen 14 from at a first end and fluidly connected to drainage reservoir 106 at a second end. In one embodiment, suction pump 104 is attached to drainage lumen 14 through a connector 20. In one embodiment, suction pump 104 is fluidly connected to proximal end 16 of drainage lumen 14 through valve 111. In one embodiment, valve 111 may be provided with a switching mechanism to allow valve 110 to be switched between on and off positions.

Suction pump 104 is configured to generate a negative pressure and thereby apply suction to drainage lumen 14 in order to draw fluid into drainage lumen 14 through the plurality of drainage holes 22. Control unit 100 further comprises a drainage reservoir 106 configured to receive fluid from drainage lumen 14 of drainage catheter 10. In one embodiment, suction pump 104 can operate passively, allowing flow from drainage lumen 14 into drainage reservoir 106 without application of negative pressure.

In one embodiment, the computer platform is electronically connected to and controls flush pump 102, suction pump 104, or both. The computer platform can also monitor flush reservoir 108 and drainage reservoir 106. In one embodiment, volume/mass of fluid in each reservoir is monitored and recorded by the computer platform.

As contemplated herein, the computer platform may comprise any computing device as would be understood by those skilled in the art, including desktop or mobile devices, laptops, desktops, tablets, smartphones or other wireless digital/cellular phones, televisions or other thin client devices as would be understood by those skilled in the art.

In one embodiment, the computer platform comprises a processor 112, a wireless transceiver 114 and a display 116. The computer platform is fully capable of sending commands to processor 112 and interpreting received signals as described herein throughout. Processor 112 can be configured to control parameters such as flow rate, frequency, volume of flushing fluid and drainage fluid and the like. The computer platform can be configured to record received signals, and subsequently interpret the received signals in real-time. In one embodiment, processor 112 is configured to compare flush input to drainage output over time. In one embodiment, the computer platform may be configured to interpret the received signals as images and subsequently transmit the images to a digital display 116. The computer platform may further perform automated calculations based on the received signals to output data.

In one exemplary embodiment, processor 112 is configured to calculate net volume drained over a specified time period (e.g., 24 hours or 7 days) or an unspecified time period. Volumes of input flush fluids and output drainage fluids can be calculated by monitoring changes in weight of the flush reservoir and the drainage reservoir. It should be understood that input flush fluids and output drainage fluids can be monitored in any suitable manner. Non-limiting examples include: the attachment of flow sensors to the flush and drain pumps or tubings to gauge changes in flow or to calculate changes in volume; the inclusion of liquid level sensors in flush and drain reservoirs such as float level sensors and ultrasonic level sensors; visual inspection of liquid levels against graded markings on flush and drain reservoirs; and the like.

The computer platform may further provide a means to communicate the received signals and data outputs, such as by projecting one or more static and moving images on a screen, emitting one or more auditory signals, presenting one or more digital readouts, providing one or more light indicators, providing one or more tactile responses (such as vibrations), and the like. In some embodiments, the computer platform communicates received signals and data outputs in real-time, such that an operator may adjust the use of the device in response to the real-time communication. In one embodiment, the computer platform is provided with a feedback mechanism, wherein if input fluid exceeds output fluid, the computer platform emits one or more signals to notify the user of possible outflow obstruction. The computer platform can also be set with a feedback loop to automatically reduce or cease flushing input when input fluid exceeds output fluid by a defined amount to prevent over-pressurization of a body cavity. The computer platform may reside entirely on a single computing device or may reside on a central server and run on any number of end-user devices via a communications network. The computing devices may include at least one processor 112, standard input and output devices, as well as all hardware and software typically found on computing devices for storing data and running programs, and for sending and receiving data over a network, if needed. If a central server is used, it may be one server or, more preferably, a combination of scalable servers, providing functionality as a network mainframe server, a web server, a mail server and central database server, all maintained and managed by an administrator or operator of the system. The computing device(s) may also be connected directly or via a network to remote databases, such as for additional storage backup, and to allow for the communication of files, email, software, and any other data formats between two or more computing devices. There are no limitations to the number, type or connectivity of the databases utilized by the control unit 100 of the present invention. In one embodiment, control unit 100 further comprises a wireless transceiver 114 to allow connection to remote databases. The communications network can be a wide area network and may be any suitable networked system understood by those having ordinary skill in the art, such as, for example, an open, wide area network (e.g., the internet), an electronic network, an optical network, a wireless network, a physically secure network or virtual private network, and any combinations thereof. The communications network may also include any intermediate nodes, such as gateways, routers, bridges, internet service provider networks, public-switched telephone networks, proxy servers, firewalls, and the like, such that the communications network may be suitable for the transmission of information items and other data throughout the system.

The software may also include standard reporting mechanisms, such as generating a printable results report, or an electronic results report that can be transmitted to any communicatively connected computing device, such as a generated email message or file attachment. Likewise, particular results of the aforementioned system can trigger an alert signal, such as the generation of an alert email, text or phone call, to alert an operator of the particular results. Further embodiments of such mechanisms are described elsewhere herein or may be standard systems understood by those skilled in the art. Referring now to Fig. 7, another exemplary control unit 200 is depicted. Control unit 200 comprises control unit 100 as described above and a three way stopcock 202. Stopcock 202 comprises a tubular shape comprising a first tube section, a second tube section, and a third tube section, each tube section having a lumen defined by a circumference, and each tube section fluidly joined to each other at a central connector. The first tube section terminates in an open end 204 opposite to the central connector, the second tube section terminates in an open end 206 opposite to the central connector, and the third tube section terminates in an open end 208 opposite to the central connector. Open end 204 is fluidly connected to the proximal end of a catheter. Stopcock 202 enables control unit 200 to fluidly communicate with single lumen catheters by selectively switching fluid access between a catheter with flush drainage reservoir 106 and flush reservoir 108. The single lumen catheter is thereby configured to act as both a flush lumen and a drainage lumen. In one embodiment, the catheter is any standard drainage catheter known in the art. Open end 206 is fluidly connected to flush pump 102. In one embodiment, open end 208 is fluidly connected to suction pump 104. In one embodiment, the fluid connections can be any suitable mechanism known in the art configured to fluidly join tubes end-to-end, including but not limited to luer locks, tube fittings, threaded connectors, barbed connectors, and the like.

In one embodiment, direction of fluid flow in stopcock 202 can be adjusted manually. In one embodiment, direction of fluid flow in stopcock 202 can be adjusted electronically.

Referring now to Fig. 8 and Fig. 9, stopcock 202 further comprises a central component 210 positioned within the central connector. Central component 210 comprises a circumference that is slightly less than the circumference of stopcock 202.

As such, central component 210 may be inserted within stopcock 202 with minimal clearance. When inserted within stopcock 202, the minimal tolerance between the outer surface of central component 210 and the inner surface of stopcock 202 prevents fluid from leaking to drainage reservoir 106 or flush reservoir 108. Central component 210 comprises a first open side 212, a second open side 214, a third open side 216 and a closed side 218 and is provided to allow directional adjustment to the fluid pathway. In one exemplary embodiment shown in Fig. 8, first open side 212 is in alignment with open end 204, wherein second open side 214 is faced to the wall of stopcock 202, third opening 216 is in alignment with open end 208 and closed side 218 is in alignment with open end 206. In this exemplary configuration, central component 210 allows fluid connection between a connected catheter and drainage reservoir 106 and blocks fluid communication from flush reservoir 108 to the catheter.

In operation, stopcock 202 comprises a drain mode and a flush mode. In the drain mode (depicted in Fig. 8), central component 210 produces a patent channel from the catheter through first open side 212 and third open side 216 into drainage reservoir 106, while closed side 218 blocks fluid communication to flush reservoir 108.

In flush mode (as depicted in Fig. 9), central component 210 produces a patent channel from flush reservoir 108 through first open side 212 and second open side 214 into the catheter, while closed side 218 blocks fluid communication to drainage reservoir 106. Central component 210 can be controlled manually or electronically to switch stopcock 202 between the drain mode and the flush mode.

Method of Use

The present invention also relates to methods for flushing a body cavity and for draining fluid from a body cavity. In some embodiments, the methods include steps of inserting the catheters of the present invention into a subject and draining fluid without clogging and with improved drainage.

Referring now to Fig. 10, an exemplary method 300 of draining a body cavity is depicted. Method 300 begins with step 302, wherein a catheter having a drainage lumen and at least one flush lumen, a plurality of outer holes draining out of each of the lumens, a plurality of inner holes fluidly connecting the drainage lumen to the at least one flush lumen, and a curved region is provided. In step 304, a stylet is inserted into a lumen of the catheter to temporarily straighten the curved region. In step 306, the curved region is positioned inside a body cavity. In step 308, the stylet is removed from the catheter to restore the curvature of the curved region. In step 310, a liquid is passed through the at least one flush lumen to flush the body cavity. In step 312, the liquid from the body cavity is drained through the drainage lumen.

In some embodiments, the step of positioning the catheter into a subject’s body cavity is performed using a guidance mechanism, including but not limited to a guide wire or X-ray guidance system. In some embodiments, the catheter can be flushed manually using a syringe. In some embodiments, the catheter can be flushed using an external pump. In some embodiments, the flushing fluid may include saline or other irrigants. In some embodiments, the flushing fluid may be selected for certain debris or occlusions, such as a fibrinolytic solution (such as tissue plasminogen activator) to disrupt fibrinous material or a deoxyribonuclease solution to reduce fluid viscosity.

In some embodiments, some or all of the method steps can be performed using the control units described elsewhere herein. For example, the step of passing a liquid through the at least one flush lumen can be carried out using a flush pump. Further, the step of passing a liquid through the drainage lumen can be carried out using a suction pump. As explained elsewhere herein, a computer platform comprising a processor, a wi fi module and a display allows monitoring and controlling the suction pump and the flush pump.

In some embodiments, control unit enables some or all of the method steps to be performed with a single lumen catheter. As such, the control unit of such system comprises a stopcock. Stopcock enables control unit to fluidly communicate with single lumen catheters by selectively switching fluid access between a catheter with flush drainage reservoir and flush reservoir. The single lumen catheter is thereby configured to act as both a flush lumen and a drainage lumen. In one embodiment, the catheter is any standard drainage catheter known in the art.

EXPERIMENTAL EXAMPLES

The invention is further described in detail by reference to the following experimental examples. These examples are provided for purposes of illustration only, and are not intended to be limiting unless otherwise specified. Thus, the invention should in no way be construed as being limited to the following examples, but rather, should be construed to encompass any and all variations which become evident as a result of the teaching provided herein.

Without further description, it is believed that one of ordinary skill in the art can, using the preceding description and the following illustrative examples, make and utilize the compounds of the present invention and practice the claimed methods. The following working examples therefore, specifically point out exemplary embodiments of the present invention, and are not to be construed as limiting in any way the remainder of the disclosure.

Example 1 : Drainage catheter with intra- and extra-luminal flush capability improves drainage rate and prevents occlusions in highly viscous in vitro fluid collection models

Image-guided percutaneous catheter drainage (PCD) of abscesses and abnormal fluid collections is the standard of care for treating a wide variety of fluid collections, resulting in reduced morbidity, mortality, hospital length of stay, and healthcare costs compared to surgical drainage (Wallace MJ et al., Journal of Vascular and Interventional Radiology. 2010 Apr 1;21(4):431-5). Clinical success rates of over 80% for intra-thoracic and intra-abdominal abscess drainage have been ubiquitously reported and fall within the threshold of efficacy proposed by quality improvement guidelines; however, there still remains a significant proportion of patients refractory to PCD (Wallace MJ et al., Journal of Vascular and Interventional Radiology. 2010 Apr 1 ;21 (4):431-5).

In the abdomen, pyogenic liver abscess drainage is associated with treatment failure resulting in repeat drainage or surgery in 16-18.5%, and is thought to be due mainly to the use of small-bore catheters and highly viscous, debris-laden, or loculated collections (Lorenz J et al., Seminars in interventional radiology. 2006

Jun;23(2): 194-204). Iliopsoas abscess drainage, while associated with a very low complication rate, results in treatment failure in over 30%; similarly, studies on perinephric PCD have suggested failure rates of over 30% as well (Lorenz J et al., Seminars in interventional radiology. 2006 Jun;23 (2): 194-204). Moreover, in a systematic review comprising 15 studies in 577 patients who underwent PCD for infected pancreatic necrosis, treatment failure leading surgical intervention occurred in nearly 40%, and definitive success was only achieved in 56% (Ke L et al., Indian Journal of Surgery. 2016 Jun l;78(3):221-8). This same trend persists across the diaphragm. In the thoracic space, chronic empyema and hematoma drainage is notoriously difficult to achieve percutaneously due to a combination of high viscosity, loculations, and organizing clot - even with the use of large-bore catheters and application of high wall suction pressures (Lorenz J et al., Seminars in interventional radiology. 2006

Jun;23(2): 194-204).

Despite high treatment failure rates, conventional catheters continue to be placed in collections that that are unlikely to resolve. While interventional radiologists have become keen to address the issue with aggressive flushing protocols and low thresholds for catheter upsizing, these efforts overlook inherent issues with current PCD technology. Moreover, such strategies are cumbersome to both patients and providers. In the 1990s, a number of studies on fluid dynamics of percutaneous drainage offered insight into optimizing conditions for draining viscous fluid collections in vitro (Park JK et al., American journal of roentgenology. 1993 Jan; 160(1): 165-9; Lee SH et al.,

Minimally Invasive Therapy. 1994 Jan l;3(4):233-7; Hoyt AC et al., Journal of vascular and interventional radiology. 1997 Mar l;8(2):267-70). However, catheter technology has been slow to evolve, and has only partially leveraged the many mechanical advantages of gravity drainage. Double-lumen sump catheters, for example, were designed to harness the theoretical advantages of air venting and irrigation as evident in nasogastric aspiration for intestinal obstruction. However, by reducing the effective drainage lumen diameter, the double-lumen was flawed in its design, and studies have shown inconsistent benefit for intra-abdominal fluid collections (Gu G et al., BMC surgery. 2015 Dec;15(l):59).

This has prompted the design of a new device aimed at leveraging the basic principles of fluid dynamics in order to solve the fundamental issues that remain with currently available drainage catheter technology.

The materials and methods are now described.

Experimental Design and Data Collection

A series of trials were performed using a sequence of conventional curved drainage catheters of increasing size (18, 20, 24, and 28 French). Each experimental condition was repeated multiple times. A compressible drainage bag was used as a fluid reservoir to mimic physiologic conditions. Initial reservoir volumes selected for each catheter size were 400, 500, 600, and 700 cc for the 18, 20, 24, and 28 Fr catheter, respectively. Fluid was allowed to flow by gravity, and subjected to two different heights (8 and 24 inches). Mass collection of fluid was performed into an open container atop an electronic balance. Mass and time were simultaneously recorded at fixed intervals for drainage rate calculations in grams per second. In vitro fluid collection models included deionized water (serous fluid model), liquified yogurt (abscess/purulent fluid model), dilute oatmeal (pancreatic/necrotic fluid model), and coagulated bovine blood (hematoma model). The pancreatic/necrotic fluid model was a particulate solution prepared using a mixture of 20% fine oats plus 20% oat flour in water (percent weight by volume). The hematoma model was prepared by adding calcium chloride to heparinized bovine whole blood product to mimic the physiological conditions of acute hematoma formation. A standard viscometer was used to measure the viscosities of each fluid. Fluids were maintained at room temperature during experimentation to allow for consistent viscosity. For prototype testing, deionized water was forcefully injected into the flush port in a pulsatile fashion at 1-minute intervals. 3- and 5-mL flushes were delivered through the 20 and 28 Fr prototypes, respectively.

Prototype Design

A standard, commercially available large-bore (20- and 28-Fr)

percutaneous drainage catheter (COOK Medical; Bloomington, IN) and small-bore (4-Fr) infusion catheter (Medtronic; Minneapolis, MN) were re-purposed to manufacture a single prototype catheter comprising an inbuilt intra-/extra-luminal flush port entrenched within the wall of the main lumen so as to not compromise the native lumen diameter (Fig. 11). To achieve this, the infusion catheter was embedded and fixed along the spine of the large-bore curved catheter. The original infusion channels were sealed off, and new flush channels were created at 1 cm intervals along the distal (curved) end of the prototype using a 30-gauge needle to create inward and outward facing puncture sites that facilitate the delivery of high-pressure flush volumes. The final product was a device with internal and external flush capability allowing for targeted irrigation and sustained patency without the need for detachment or an additional three-way valve connection.

Statistical Analyses All statistical analyses were performed using R software version 3.2.2 (R Core Team; Vienna, Austria). A p-value < 0.05 was considered statistically significant for all two-sided tests. Fisher’s exact test was used for categorical variable comparisons. A Mann-Whitney U test was used to compare continuous variables. Multiple linear regression was performed to assess for associations between various experimental conditions and drainage outcomes. Added volumes due to flushing were subtracted out and controlled for in cumulative drainage calculations.

The results are now described.

Serous Fluid Model

Control experiments (without flushing) were performed using deionized water to simulate drainage of serous fluid using 18, 20, 24, and 28 Fr catheters, each subjected to two drainage heights (8 and 24 inches) (Fig. 12A, Fig. 12B). Average drainage rates were 11.2, 12.1, 19.3, and 27.2 g/s at 8” height, and 13.1, 18.8, 29.4, 45.7 g/s at 24” height, for 18, 20, 24, and 28 Fr catheters, respectively. Flush trials using the 20 and 28 Fr prototype catheters had no effect on drainage rate. Additional trials were performed with a tapered luer-lock attachment at the proximal end of the catheter to simulate a common clinical scenario in which a large-bore curved catheter is connected to a drainage bag with silicone tubing via a lumen-narrowing adapter. At 8” height, average drainage rates were 5.3, 4.4, 4.7, and 5.2 g/s for the 18, 20, 24, and 28 Fr catheters, respectively (Fig. 13 A, Fig. 13B). As expected, there was no appreciable difference in rate between catheter sizes owing to the adapter’s intrinsically fixed narrow luminal diameter.

Abscess/Purulent Fluid Model

Experiments were performed using a flavored yogurt beverage available over the counter (organic low-fat yogurt smoothie; Trader Joe’s; Monrovia, CA, USA). Each scenario was repeated and averaged over four trials. For 8” height, average drainage rates were 0.27, 0.19, 0.36, and 0.81 g/s for 18, 20, 24, and 28 Fr catheters, respectively. For 24” height, drainage rates were 0.85, 1.0, 3.6, and 6.6 g/s for 18, 20, 24, and 28 Fr catheters, respectively. Flush trials were performed under the same conditions for the 20 and 28 Fr prototype catheters. For the 20 Fr prototype, average drainage rates were 0.34 g/s at 8” (Fig. 14A, Fig. 14B) and 1.2 g/s at 24” height. For the 28 Fr prototype, average drainage rates were 1.2 g/s at 8” (Fig 15 A, Fig. 15B) and 6.8 g/s at 24” height.

Pancreatic/Necrotic Fluid model

Experiments were performed using a mixture of 20% fine oats (Kroger Company; Cincinnati, OH, USA) and 20% oat flour (Montana Gluten Free; Belgrade,

MT, USA) in deionized water (% weight per volume) at an 8” height. Whole oats were broken down into 1-3 mm sized particles using a food processor. Each scenario was repeated and averaged over eight trials due to a large observed variability between trials. The average drainage rate for 28 Fr control trials was 0.23 g/s with an average of 41.1% total volume drained (median: 36.2%, range: 2.01-93.9%), compared to 0.35 g/s with an average of 69.0% total volume drained (median: 80.6%, range: 54.4-91.8%) for 28 Fr prototype flush trials (Fig. 16A, Fig. 16B). 20 Fr catheter drainage trials with oats were all failures as a result of immediate catheter occlusion at the start of mass collection.

Hematoma Model

28 French experiments were conducted using citrated bovine whole blood (LAMPIRE Biological Labs, Inc.; Pipersville, PA, USA) with initial reservoir volumes of 400 cc at a height of 8”. Acute hematoma formation was simulated by adding a small amount of calcium chloride to induce coagulation. Trials were repeated three times each for control and flush runs. The average drainage rate for 28 Fr control trials was 0.25 g/s with an average of 20.1% total volume drained (median: 19.5%, range: 8.30-32.5%), compared to 0.84 g/s with an average of 80.3% total volume drained (median: 79.6%, range: 72.3-89.0%) for 28 Fr prototype flush trials (Fig. 17A, Fig. 17B).

Percutaneous catheter technology has undergone little advancement over the past several decades despite high failure rates and several unaddressed limitations to the current technology (Wallace MJ et al., Journal of Vascular and Interventional Radiology. 2010 Apr 1;21(4):431-5; Lorenz J et al., Seminars in interventional radiology. 2006 Jun;23(2): 194-204; Ke L et al., Indian Journal of Surgery. 2016 Jun l;78(3):221-8; Park JK et al., American journal of roentgenology. 1993 Jan; 160(1): 165-9; Lee SH et al., Minimally Invasive Therapy. 1994 Jan l;3(4):233-7; Hoyt AC et al., Journal of vascular and interventional radiology. 1997 Mar l;8(2):267-70; Gu G et al., BMC surgery. 2015 Dec;15(l):59). A number of older studies provide in vitro evidence that specific characteristics of the catheter itself can drastically influence the efficacy of drainage. By going back to the basic principles of fluid dynamics and Poiseuille’s Law, one can begin to understand and revisit these limitations, and innovate new ways to overcome them. While several previous efforts - including the development of double-lumen sump catheters (Hoyt AC et al., Journal of vascular and interventional radiology. 1997 Mar l;8(2):267-70) and infusion of lytic agents (Park JK et al., American journal of roentgenology. 1993 Jan; 160(1): 165-9) - aimed to address some key issues, clinical data in support of their widespread use is lacking.

Presented herein is a novel prototype drainage catheter comprising an inbuilt intra-/extra-luminal flush port embedded within the primary catheter wall.

Preliminary in vitro results demonstrate that frequent targeted flushing of highly viscous, debris-laden fluids can prevent occlusions and improve flow rates. In summary, the following key limitations of standard PCD are addressed by the proposed prototype:

Limitation: Catheter irrigation strategies involve narrow diameter, rate- limiting attachments (e.g. three-way valve, silicone tubing, etc.)

Improvement: Flushable side port provides simple irrigation access without a need for detaching or accessory connectors (Fig. 1, connector 20).

Limitation: Nonhomogeneous debris-laden collections are occlusive; gravity-dependent particulate matter tends to settle and aggregate.

Improvement: Embedded flush lumen with outward-facing (extra-luminal) holes allows for continuous or frequent flushing/agitation of collections (Fig. 2, outer flush holes 28).

Limitation: Extracorporeal drainage lumen becomes occluded.

Improvement: Embedded flush lumen with inward-facing (intra-luminal) holes allows for continuous or frequent flushing of the main lumen (Fig. 2, inner flush holes 30). The disclosures of each and every patent, patent application, and publication cited herein are hereby each incorporated herein by reference in their entirety. While this invention has been disclosed with reference to specific embodiments, it is apparent that other embodiments and variations of this invention may be devised by others skilled in the art without departing from the true spirit and scope of the invention. The appended claims are intended to be construed to include all such embodiments and equivalent variations.

Claims

CLAIMS What is claimed is:

1. A catheter comprising:

an elongate tube having an open proximal end, an open distal end, a length therebetween, and a drainage lumen within the tube extending between the proximal and distal ends;

a plurality of holes positioned on a wall of the elongate tube, each of the holes fluidly connected to the drainage lumen; and

at least one flush lumen positioned parallel to the tube, the at least one flush lumen having a plurality of inner and outer flush holes, wherein the inner flush holes fluidly connect the flush lumen to the drainage lumen.

2. The catheter of claim 1, wherein the distal end of the elongate tube comprises a curved region.

3. The catheter of claim 2, wherein at least one of the plurality of holes of the drainage lumen resides within the curved region.

4. The catheter of claim 2, wherein at least one of the plurality of flush holes of the at least one flush lumen resides within the curved region.

5. The catheter of claim 1, wherein the plurality of holes of the drainage lumen is evenly spaced over the length of the elongate tube.

6. The catheter of claim 1, wherein the plurality of holes of the drainage lumen are larger than the plurality of flush holes.

7. The catheter of claim 1, wherein the drainage lumen has a diameter that is greater than a diameter of the at least one flush lumen.

8. The catheter of claim 1, wherein the plurality of inner and outer flush holes is evenly spaced over the length of the elongate tube.

9. The catheter of claim 1, wherein the distal end is positionable in a subject’s body cavity.

10. The catheter of claim 1, wherein at least a portion of the length of the elongate tube is reinforced with wire.

11. The catheter of claim 1, wherein a connector is attached to the proximal end of the drainage lumen, the at least one flush lumen, or both.

12. The catheter of claim 11, wherein the connector is selected from the group consisting of: a luer lock, a tube fitting, a threaded connector, and a barbed connector.

13. The catheter of claim 1, wherein at least one of the flush lumens is positioned within a wall of the elongate tube.

14. The catheter of claim 1, wherein the catheter further comprises a control unit comprising:

a flush pump fluidly connected to the proximal end of the flush lumen at a first end and fluidly connected to a flush reservoir at an opposing second end, wherein the flush pump is configurable to pump flushing fluid from the flush reservoir into the flush lumen;

a suction pump fluidly connected to the proximal end of the drainage lumen at a first end and fluidly connected to a drainage reservoir at an opposing second end, wherein the suction pump is configurable to apply a suction to the drainage lumen in order to draw fluid into the drainage reservoir;

a weigh scale positioned beneath each of the flush reservoir and drainage reservoir; and

a computer platform configured to monitor and control the flush pump and the suction pump.

15. The catheter of claim 14, wherein the computer platform measures decreases in a volume of fluid in the flush reservoir and increases in a volume of fluid in the drainage reservoir using the weigh scales.

16. The catheter of claim 15, wherein the computer platform is configured to provide an alert if the decrease in the volume of fluid in the flush reservoir exceeds the increase in the volume of fluid in the drainage reservoir.

17. The catheter of claim 15, wherein the computer platform is configured to decrease or cease a flow of flushing fluid from the flush reservoir if the decrease in the volume of fluid in the flush reservoir exceeds the increase in the volume of fluid in the drainage reservoir.

18. The catheter of claim 14, wherein the control unit further comprises a three-way stopcock, wherein the stopcock comprises:

a tubular body having a first tube section, a second tube section, and a third tube section, wherein each of the first, second, and third tube sections comprises a lumen and are fluidly connected at a first end to a central connector and terminate in an opening at a second end opposite to the first end; and

a central component comprising a circumference that is slightly less than a circumference of the central connector, such that central element may be inserted within the central connector with minimal tolerance, and wherein the central component comprises a first open side, a second open side, a third open side, and a closed side;

wherein the second end of the first tube section is connected to the proximal end of a standard catheter;

wherein the second end of the second tube section is fluidly connected to the flush pump; and

wherein the second end of the third tube section is fluidly connected to the suction pump.

19. The catheter of claim 15, wherein the stopcock comprises:

a drain mode, wherein the central component produces a patent channel from the drainage lumen through the first open side and the third open side into a drainage reservoir; and a flush mode, wherein the central component produces a patent channel from a flush reservoir through the first open side and the second open side into a flush lumen.

20. A method for removing fluid from a body cavity in a subject, comprising: providing a catheter having a drainage lumen and at least one flush lumen, a plurality of outer holes draining out of each of the lumens, a plurality of inner holes fluidly connecting the drainage lumen to the at least one flush lumen, and a curved region;

inserting a stylet into a lumen of the catheter to temporarily straighten the curved region;

positioning the curved region inside a body cavity;

removing the stylet from the catheter to restore the curvature of the curved region; passing a liquid through the at least one flush lumen to flush the body cavity; and draining the liquid from the body cavity through the drainage lumen.