Patent Application
20230226267
There are no cross-related applications.
The present invention generally relates to a dome catheter system and method of installation thereof. In particular, the present invention relates to a dome catheter system comprising catheters having helical ridges and a lattice internal structure.
Perianal fistula in Crohn's disease (CD) affects almost one third of patients, greatly compromising their quality of life. This condition remains a very challenging problem to overcome both for physicians as well as surgeons, Despite new medical and surgical developments, the fistulas are only cured in less than one out of five patients after extensive medical and surgical management, affecting profoundly the socioeconomic situation and quality of life of the patient. In addition, perianal Crohn's fistulas are responsible for an enormous healthcare consumption. Management of perianal fistulas in Crohn's disease must therefore be considered as one of the most important unmet needs in patients suffering from inflammatory bowel disease (IBD). This has recently been recognized and highlighted by the European Crohn's and Colitis Organisation in the fifth scientific workshop addressing perianal fistula in Crohn's disease and by the Crohn's and Colitis Foundation (CCF) facilitating a working group brainstorming on “challenges in IBD research”.
Evidence is accumulating that medical therapy such as anti-TNF can only provide sustained clinical remission in less than one out of five patients compared to placebo. However, the data of the CCF supported PISA II trial (PISA Study: Multimodal treatment of Perianal fistulas in Crohn's disease: Seton versus anti-TNF versus Advancement Plasty) demonstrates that in the anti-TNF group, very few of the clinically externally closed fistulas show true healing on MRL A drop of the through levels is associated with the reopening of the external openings indicating that a clinical response, if any, is not durable. Overall, almost no MRI closure in the anti-TNF patient group and withdrawal of costly medication results in re-opening of the fistula (only 3% of patients on anti-TNF showed closure with MRI, as shown in the PISA Study II) while surgical closure was effective in nearly one out of two (44% of the patients who underwent surgical closure).
A primary beneficiary to a solution to the above stated problem are Crohn's Disease and Ulcerative Colitis patients which, according to the Centres for Disease Control and Prevention, includes at least 5 million people in Europe and North America with an additional 100,000 to 200,000 newly diagnosed cases each year in these areas alone. Moreover, annual direct healthcare costs of CD in Europe alone are estimated at approximately 4.6 to 5.6 billion Euros. Non-IBD patient groups are the secondary beneficiary to the above stated problem who may suffer from cryptoglandular perianal fistula, with the estimated incidence in Europe being 1.2-2.8 per 10 000 population, with a peak incidence between the age of 20 and 40 years.
A third category of patients benefiting from a solution to the above stated problem are patients which develop enterocutaneous abscesses and fistula as result of a surgical intervention of the digestive tract.
Current deep wound drainage systems are intended for passive drainage of fluids having a low viscosity such as blood and seroma following trauma or surgery. These are not well adapted for eliminated granular tissue as can be found in fistulas nor have the adequate rigidity of features to be inserted or removed through a perianal or enterocutaneous fistula.
Several systems for the management of deep abscesses and fistula tracts are known in the prior art, however they are almost exclusively passive draining systems operating on gravity.
Exceptionally, the Endo-SPONGE™ (B. Braun Medical, Melsungen, Germany), is a commercially available active device which has been used to address the unmet medical need of the holistic approach to fistula management per se via a natural orifice. It is designed for transluminal management of anastomotic leaks of esophageal or colorectal anastomosis and approved for the treatment of abscess cavities from anastomotic leakages of colorectal/coloanal and gastroesophageal anastomosis but is also used off-label in the treatment of fistulas and Problems related with existing solutions, local anesthesia, etc.).
Despite being adapted for use in perianal fistula, the Endo-SPONGE™ presents a great number of shortcomings.
Firstly, the use of the EndoSPONGE™ without transluminal access is painful to the patient for both insertion and removal. General anesthesia and hospital care are therefore typically needed. Moreover, the granulation tissues adhere to the sponge causing tearing and bleeding of the tissue when removing the sponge.
The Endo-SPONGE™ is further only supplied in one size and it is subsequently intended to be adjusted in size by a surgeon, therefore relying heavily on the skills of the specific surgeon. In the same vein, customizing the sponge increases the risk of sponge debris being left inside the wound.
Another disadvantage lies in the sponge not being visible in MRI scans, and therefore not allowing to specify the pace of removing it based on the state of healing seen in MRI scans.
Moreover, the organic debris passing through the sponge (such as blood or pus) causes the sponge to clog which compromises its function. According to B. Braun Medical, the sponge may stay in-dwelling for up to 3-4 days, but practical usage indicates that it may clog faster than indicated.
Finally, the granulation tissue may adhere to the sponge which causes tearing and bleeding of the tissue when removing the sponge.
Alternatively, surgeons also use hand-made catheter tips in fistula management. These are catheter tips tailored to the patient's specific situation and are typically made using punctured drain ends hand-braided with silver mesh. The disadvantages of this solution include the inability to standardize and certify this method, risk of faulty execution of the method, and the lack of visibility of the drain tip during MRI imaging, and loss of parts of the assembled device in the patient.
There is therefore a need for a catheter dome adapted to overcome the shortcomings of the prior art.
The shortcomings of the prior art are generally mitigated by a catheter for transcutaneous and transluminal vacuum closure of perianal or entero-cutaneous fistulas and abscesses, the catheter comprising a body having a flexible and resilient enlarged portion, the body comprising a series of openings fluidly connected to a catheter chamber, and a tube configured to be connected to a vacuum generating system.
In another aspect of the invention, the catheter may comprise a resilient structure within the catheter chamber, wherein the resilient structure may be a spatial lattice structure allowing maintenance of the structural integrity of the catheter and promoting drainage, and wherein the enlarged portion and the resilient structure may be unitary. The body may further comprise ridges extending in a longitudinal direction of the enlarged portion, with the ridges being helicoidal, wherein the ridges may channel fluids, pus and tissue debris into the openings, and wherein the openings may be disposed between the ridges.
In yet another aspect of the invention, an outer surface of the catheter may be low friction and non-tissue adherent, and the enlarged portion may be made of biocompatible flexible and resilient material selected from silicone, PVC, and other medical grade polymers and elastomers. The catheter may further be made of material which is visible during medical imaging, the material of the catheter comprising a radio-opaque formulation or coating such as barium sulfate. The low friction characteristics of the outer surface of the catheter may enable withdrawal, advancement and replacement of the catheter without the necessity of general anesthesia.
In yet another aspect of the invention still, the catheter may comprise a closed internal channel for advancement of the catheter adapted to receive a rigid guidewire and a concentration of the openings may vary along a longitudinal axis of the body. An angle between an axis of an opening and a surface of the enlarged portion may also vary along a longitudinal axis of the enlarged portion, wherein the angle may be orthogonal at a lower portion of the enlarged portion and decreases near a tip of the enlarged portion. The catheter may be manufactured through a 3D printing process, wherein a size and geometry of the catheter may be custom fit to a patient's anatomy based on imaging data. The tube may comprise an angled portion and the enlarged portion may be shaped as a dome.
The present invention may also be realized by a kit comprising a plurality of the catheters, the catheters varying in size for the progressive closure of said fistulas and abscesses.
The present invention may further be realized by a method for treating perianal or entero-cutaneous fistula and abscess, the method comprising selecting a first catheter from a plurality of catheters having different lengths and diameters, each of the catheters comprising a body having a flexible and resilient enlarged portion which comprises a series of openings fluidly connected to a catheter chamber, inserting the first, catheter in the fistula or the abscess and, after a predetermined period of time, replacing the first catheter with a second catheter of the plurality of catheter, the enlarged portion of the second catheter having a smaller length and diameter than the enlarged portion of the first catheter.
In another aspect of the invention, the method may comprise characterizing the fistula or abscess and selecting one of the catheters based on the characterized fistula or abscess and inserting the first enlarged portion of the body may comprise rotatably inserting the first enlarged portion of the body into the fistula or the abscess.
The present invention may further yet be realized by a catheter for transcutaneous and transluminal vacuum closure of perianal or entero-cutaneous fistulas and abscesses, the catheter comprising a body comprising a series of openings fluidly connected to a catheter chamber, a tube in fluid communication with the body and connectable to a vacuum generating system, and a flange configured to define a maximum insertion length of the catheter into the fistula or abscess.
In another aspect of the invention, the catheter may comprise a flexible enlarged portion and a resilient structure within the enlarged portion, wherein the resilient structure may be a spatial lattice structure maintaining the, structural integrity of the catheter and promoting drainage, and wherein an outer surface of the body may comprise ridges extending in a longitudinal direction of the body, the ridges being helicoidal, and wherein the ridges may channel fluids, pus and tissue debris into the openings. An outer surface of the catheter may be low friction and non-tissue adherent.
Other and further aspects and advantages of the present invention will be obvious upon an understanding of the illustrative embodiments about to be described or will he indicated in the appended claims, and various advantages not referred to herein will occur to one skilled in the art upon employment of the invention in practice.
The above and other aspects, features and advantages of the invention will become more readily apparent from the following description, reference being made to the accompanying drawings in which:
FIG. is a front close-up view of a catheter body of the catheter of
A novel dome catheter system for transcutaneous vacuum-assisted closure of perianal or enterocutaneous abscesses and fistula tracts and method thereof will be described hereinafter. Although the invention is described in terms of specific illustrative embodiments, it is to be understood that the embodiments described herein are by way of example only and that the scope of the invention is not intended to be limited thereby.
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In preferred embodiments, the outer surface 122 of the catheter body 100 is smooth and free of irregularities. The smoothness of the outer surface 122 may allow easier insertion of the catheter 10 within an abscess or fistula while further generating less fluid friction with the pus and debris passing across the outer surface 122 and being vacuumed out of said abscess or fistula.
The catheter 10 may be made of a biocompatible flexible and resilient material, such as, but not limited to, silicone, PVC, and other medical grade polymers and elastomers. While the catheter 10 may be made of one material, in other embodiments, it may be desirable to produce other elements of the catheter using a different material. For example, the tube 200 may be made with one biocompatible material while the catheter body 100 of the catheter 10 may be made of another material. The resiliency of the catheter 10 may be selected to allow said catheter 10 to be easily inserted within an abscess or fistula while preventing said catheter 10 from collapsing once installed therein.
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In a preferred embodiment, the ridges 110 longitudinally extend along a substantial portion or along the entirety of the catheter body 100. The ridges 110 are typically made of flexible yet resilient material. The length and the flexibility of the ridges 110 generally allow the catheter body 100 to collapse or having a reduced diameter to adapt to the size of a tract or abscess cavity in which the catheter body 100 is inserted. The length and flexibility further ease insertion and extraction of the catheter 10. Accordingly, the insertion or extraction of the catheter 10 may advantageously be performed by an individual lacking the qualifications of a surgeon such as, for example, by a specialized nurse in an outpatient clinic or even in a home care environment. Moreover, the insertion and/or extraction of the catheter 10 may be less painful for an individual thus allowing it, in certain cases, to be installed without the need of anesthesia,
The helical ridges 110 extending a substantial length of the catheter body 100 may further help channel fluids, namely pus and debris (such as granulation tissue), thereby allowing them to better flow through the catheter 10.
In certain embodiments, the outer surface of the catheter tube 200 may be completely smooth or be partially covered with apertures 260 for the purpose of drainage. In some embodiments, the tube 200 may further be covered with the measurement markings 220 designed to enable precise insertion.
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In certain embodiments, the structure 170 may comprise a plurality of interconnected columns 172. The structure 170 may further comprise spherical knots 174 connected to the columns 172 or connected to an inner surface 124 of the catheter body 100. in further embodiments, the spherical knots 174 may contact the inner surface of the catheter body 100.
In preferred embodiments, the diameter of the columns 170 may range between 0.3 and 1.5 mm and the diameter of the spherical knots 174 may range between 0.3 and 1.5 mm. The length of the columns 172 may vary from 0.5 mm to 5 mm. Each of the spherical knots 174 may interconnect up to six columns 172. In the illustrated embodiment, the structure 170 comprises six sets of vertically disposed knots 174 at a same general position along the longitudinal axis of the catheter body 100, The columns 172 and knots 174 may he arranged in such a way to define canals within the internal lattice structure 170 along the longitudinal axis of the catheter body 100. In certain embodiments, the canals have an effective diameter of up to 4 mm thereby allowing the surgeon to insert a guidewire inside the catheter 10, if necessary.
The spatial lattice structure 170 of the columns 172 and knots 174 may be made of the same flexible and resilient biocompatible materials of the remainder of the catheter body 100. In certain embodiments, the spatial lattice structure 170 and the remainder of the catheter body 100 may be unitary and manufactured using a 3D minting technique. Understandably, different materials or arrangements of the spatial lattice structure 170 may be used in future embodiments, as long as the structure 170 supports the catheter body 100 from collapsing, while maintaining the flexibility of the said catheter 10.
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In certain embodiments, the apertures 160 may be oriented at an angle relative to the surface 122 of the catheter body 120. For example, and as shown in
In a preferred embodiment, the apertures 160 are disposed between the ridges 110, as the ridges 110 provide structural support for the catheter body 100. Moreover, a denser arrangement of the apertures 160 on the surface 122 of the catheter body 100 may provide increased patency and prevent clogging. The denser arrangement generally implies having small apertures 160. In certain embodiments, the concentration of apertures 160 may vary along the longitudinal length of the catheter body 100. For example, in the illustrated embodiments, the concentration of apertures 160 varies gradually from a lowest density near the lower portion 140 and to a highest density near the tip 102. This arrangement of concentrations and the aforementioned angling of the apertures 160 may allow a greater pressure distribution inside the catheter chamber 130 with most of the pressure being exerted near the top of the chamber 130, while some pressure is still exerted near its lower parts. This may allow the top of the cavity to heal faster, while preventing the granulation tissue from overgrowing on the lower parts.
Broadly, the catheter 10 performs a more effective transcutaneous vacuum closure of perianal or entero-cutaneous abscesses and fistulas when it comprises a higher concentration of apertures 160 and apertures 160 having a smaller cross-sectional area. The number of apertures 160 or density shall provide enough flow to adequately drain the tissues around the inserted catheter 10.
Referring back to the embodiment illustrated at
In some embodiments, by limiting the insertion depth of the catheter 10, the medical practitioner may easily select, the adequate catheter 10 head that has the specifications required for the specific situation (i.e., dimensions, shape, etc.).
As previously stated, the tube 200 may be angled behind the flange 240 with respect to the plane of the flange 240, which may facilitate a constant suction and protects the external tube 200 from bending, while providing the patient with a more comfortable placement of the tube 200. The flange 240 may have any suitable diameter or thickness. For example, the flange 240 may be about 3 mm thick or less with a diameter of about 20 mm. Moreover, the contact surface 242 may be adapted to contact the skin to ensure a desirable vacuum seal level. In certain embodiments, contact surface 242 may be configured to receive a stoma paste and may be flat, thus improving a better vacuum sealing level and/or ensuring a more secure installation of the catheter 10.
The external tube 200 may have any suitable internal and external diameters. For example, the tube 200 may have an external diameter of about 7 mm and an internal diameter of about 4 mm.
It may be appreciated that the catheter 10 may be made in any size and shape according to the requirements of a specific patient and can be custom 3D printed based on MR imaging of their septic cavity and tubing.
The present invention further comprises a parametric method of designing and manufacturing the catheter 10. In certain embodiments, the method may comprise measuring the septic cavity of a patient and inputting said measurements into a computerized system, such as using an interface. The method may further comprise the computerized system processing several measured parameters (e.g., height, depth, width and shape of the cavity) and automatically defining an adequate custom shape of one or more catheters designed for one particular patient's treatment.
In certain embodiments, a radio-opaque formulation may be used to produce the catheter 10 and/or a coating such as barium sulfate may be used to coat the catheter 10. A catheter 10 in accordance with these embodiments may be easier to locate using medical imaging means of the patient's body.
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The method 400 further comprises inserting the sterile catheter 310 into the cavity 430. The insertion may be combined to a twist motion up to the skin surface. In embodiments where the catheters 310 comprise a flange, the flange may be inserted up to the patient's skin surface and the contact surface 242 of the flange may adhere to or at least contact the skin. In embodiments where the catheters 310 are straight, a careful measurement of the insertion is required for a good placement of the catheter 310.
In certain embodiments, inserting the catheter 430 may require using a guidewire inserted inside the catheter 310 which is removed once the catheter 310 is placed properly. Once the guidewire is removed, an end of the tube being opposite to the catheter body is connected to an active negative pressure and drain system 440. The negative pressure pump is typically capable of providing a suitable negative pressure. The connection may be performed via an additional external tube, In certain embodiments, one or more adapters may be used to connect the tube to the pump or to the external tube. In a preferred embodiment, a pump capable of generating a −125 mmHg negative pressure may be used and the pump may be mobile to allow the patient to function normally. The method 400 may further comprise adjusting the pump to generate a negative pressure in the range from −25 mmHg to −125 mmHg to allow for a more precise adjustment of the catheter's patency.
The method 400 further comprises performing the treatment for a predetermined period of time with a predetermined pressure 450. The pump should preferably remain airtight for the predetermined duration (typically 1-2 days) after which the cavity will have shrunk to the point that the catheter 310 needs to be exchanged for a smaller one. The method may therefore comprise the step of removing the catheter and replacing it with the next smaller catheter in the treatment protocol 460. Active drainage of the cavity may prevent accumulation of pus and debris and may allow healing i.e., shrinkage of the cavity.
The medical practitioner should make the decisions on how to carry out the treatment, for example, by prescribing additional painkillers or changing the pace of exchange of catheters, The MRI scans carried out throughout the treatment may additionally help a medical practitioner to assess how the treatment progresses. In future the treatment may be accompanied by a mobile application that will analyze patients' data and provide tips on how to carry out the treatment.
While illustrative and presently preferred embodiments of the invention have been described in detail hereinabove, it is to be understood that the inventive concepts may he otherwise variously embodied and employed and that the appended claims are intended to be construed to include such variations except insofar as limited by the prior art.
