Nasal transluminal feeding catheter

Abstract

In one aspect, a nasal transluminal feeding catheter (1) according to the present disclosure comprises a tube (40) and a connector (10) that is provided at one end of the tube (40). The tube (40) includes a plurality of protrusions (41) that are formed integrally with an inner circumferential surface of the tube (40) and that extend along the lengthwise direction of the tube (40). Each protrusion (41) faces a portion (42) of the tube (40) in which protrusions (41) are not formed. A cross-section of the tube (40) can be deformed to be flat when the portion (42) of the tube (40) in which protrusions (41) are not formed is bent by pharyngeal pressure or intraesophageal pressure. The thickness of the portion (42) of the tube (40) in which protrusions (41) are not formed is preferably not more than 0.6 mm.

Description

Nasogastric tube feeding catheter

[0001] The present invention relates to a nasal tube feeding catheter and a medical device for nasal tube feeding therapy including the same.

[0002] Malnutrition among elderly people hospitalized in acute phases has become a social problem. It has been reported that approximately 40% of elderly people hospitalized are malnourished. Malnutrition, for example, slows recovery after surgery and has a significant impact on medical and nursing care costs.

[0003] There are two main nutritional intake methods currently used in acute care nutritional therapy. The first is oral intake. This is a physiological method of nutritional intake, but it has the disadvantage of being easily affected by a patient's reduced ability to eat and swallow, and reduced motivation, which can lead to malnutrition. The second is nasogastric tube feeding. This is an efficient method of nutritional intake, but because it does not use the mouth or throat, it has the disadvantage of reduced ability to eat and swallow.

[0004] One way to take advantage of the advantages of the two nutritional intake methods mentioned above while compensating for the disadvantages is to use an existing catheter used in nasogastric tube feeding therapy, which is left in the body from the nose or mouth to the inside of the digestive tract, and then the patient takes the nutrition orally. However, when a large-diameter (10-14 Fr) existing catheter is left in place, problems arise, such as difficulty swallowing, residual or reflux of food bolus, and discomfort in the pharynx, making oral feeding training difficult. When a small-diameter (6.5 Fr) existing catheter is left in place, the above problems are alleviated, but the small diameter makes the lumen prone to clogging, making it impossible to administer highly viscous nutrients.

[0005] Patent Document 1 discloses a catheter capable of administering nutrients that flattens due to the internal pressure of the pharynx and esophagus. While the catheter disclosed in Patent Document 1 is believed to be able to reduce dysphagia and discomfort, it suffers from the problem that the lumen collapses when the catheter is pressed by pharyngeal pressure, making it difficult to ensure a sufficient flow path for nutrients. Furthermore, the catheter disclosed in Patent Document 1 is equipped with an outwardly expandable balloon portion and is intended for use as a device for treating swallowing disorders, but it does not enable the implementation of the two nutritional intake methods mentioned above.

[0006] Japanese Patent Application Publication No. 10-118190

[0007] In nasogastric tube feeding catheters, there is a trade-off between reducing dysphagia and discomfort while the catheter is in place and ensuring a sufficient flow path for nutrients. There are currently no nasogastric tube feeding catheters that allow for easy oral nutritional intake while indwelling in the body and that ensure a sufficient flow path for nutrients while indwelling.

[0008] Therefore, in one aspect, the present invention provides a nasal tube feeding catheter that reduces dysphagia and discomfort during placement and ensures a sufficient flow path for nutrients, and a medical device for nasal tube feeding therapy that includes the same.

[0009] The nasal tube feeding catheter of the present invention comprises a tube and a connector provided at one end of the tube, wherein the tube comprises a plurality of protrusions integrally formed on the inner peripheral surface of the tube and extending along the longitudinal direction of the tube, each protrusion facing a portion of the tube where no protrusions are formed, and wherein the portion of the tube where no protrusions are formed is bent by pharyngeal pressure or intraesophageal pressure, allowing the cross section of the tube to be deformed into a flat shape.

[0010] In one aspect, the present invention is a medical device for nasal tube feeding therapy, which includes the nasal tube feeding catheter of the present invention and a guide device. The guide device includes an insert that can be inserted into and removed from the lumen of the nasal tube feeding catheter and has a bending strength greater than that of the tube that constitutes the nasal tube feeding catheter.

[0011] In the nasal tube feeding catheter of the present invention, the convex portions integrally formed on the inner circumferential surface of the tube each face a portion of the tube where no convex portions are formed. When the tube is compressed by pharyngeal pressure or esophageal pressure, the portion of the tube where no convex portions are formed bends, flattening the cross section of the tube. The portion of the tube where the convex portions are formed does not bend due to pharyngeal pressure or esophageal pressure. When the tube is compressed by pharyngeal pressure or esophageal pressure, the tops of the convex portions contact the inner circumferential surface of the tube, and the tops of the convex portions contact the portion of the tube where no convex portions are formed. Therefore, the cross section of the tube can be deformed more flattened than when, for example, the tops of the convex portions abut against each other. Furthermore, in the flattened tube, a flow path is secured at least between adjacent convex portions. Therefore, the nasal tube feeding catheter of the present invention can simultaneously reduce dysphagia and discomfort during placement and ensure a sufficient flow path for nutrients.

[0012] FIG. 1 is a perspective view of a nasal tube-feeding catheter according to one embodiment of the present invention. FIG. 2 is another perspective view of the nasal tube-feeding catheter shown in FIG. 1. FIG. 3 is a partially enlarged cross-sectional view of the nasal tube-feeding catheter shown in FIG. 1. FIG. 4A is an enlarged cross-sectional view of a tube constituting the nasal tube-feeding catheter shown in FIG. 1, and FIG. 4B is a schematic cross-sectional view showing the tube shown in FIG. 4A after being pressed radially until the apex of its convex portion abuts on a portion of the tube where the convex portion is not formed. FIG. 5A is a partially enlarged perspective view of a tube of a nasal tube-feeding catheter according to another embodiment of the present invention, and FIG. 5B is a cross-sectional view thereof. FIG. 6A is a partially enlarged perspective view of a tube of a nasal tube-feeding catheter according to yet another embodiment of the present invention, and FIG. 6B is a cross-sectional view thereof. FIGS. 7A to 7D are each an enlarged cross-sectional view of a tube of a nasal tube-feeding catheter according to another embodiment of the present invention. FIG. 8A is an enlarged cross-sectional view of a tube constituting a nasal tube feeding catheter according to yet another embodiment of the present invention, and FIG. 8B is a schematic cross-sectional view showing the tube shown in FIG. 8A being pressed radially until the apex of the convex portion of the tube abuts against a portion of the tube where the convex portion is not formed. FIG. 9A is a perspective view showing a state in which a guide wire of a stylet device is inserted into a nasal tube feeding catheter according to one embodiment of the present invention. FIG. 9B is a cross-sectional view of FIG. 9A. FIG. 10A is a perspective view showing a state in which a stylet connector of a stylet device is connected to a catheter connector of a nasal tube feeding catheter according to one embodiment of the present invention. FIG. 10B is a cross-sectional view of FIG. 10A. FIG. 11 is an explanatory diagram showing nasal tube feeding therapy being performed using a medical device for nasal tube feeding therapy according to the present disclosure. FIG. 12 is a schematic diagram for explaining a method for evaluating the kink resistance of a tube. Fig. 13A is a schematic diagram illustrating the state immediately before measuring the bending strength of the insertion tip of the tube, Fig. 13B is a schematic diagram illustrating the state in which the insertion tip of the tube buckles after the bending strength test, Fig. 14A is a schematic diagram illustrating a method for evaluating the compressibility of the tube, and Fig. 14B is a cross-sectional view showing the state when the tube is pressed in the radial direction.

[0013] The nasal tube feeding catheter (hereinafter sometimes referred to as "nutrition catheter") of the present invention is placed in the patient's body from the nose or mouth to, for example, the inside of the esophagus, the inside of the stomach, the inside of the duodenum, or the inside of the jejunum.

[0014] When the tube constituting the nutrition catheter of the present invention is compressed radially at a pressure of 150 mmHg, the maximum thickness of the tube in the compression direction is preferably 2.5 mm or less. This embodiment has the advantage that a mixed intake, in which nutrition is taken orally (meals) as the basis and nutritional deficiencies are supplemented with nasogastric tube feeding therapy, can be performed with minimal discomfort.

[0015] More specifically, nasogastric tube feeding therapy has the advantage of reliably and efficiently delivering the necessary nutrients to the patient's stomach. However, because the mouth and throat are not used, it can impair the patient's swallowing function. For this reason, medical professionals first attempt oral nutrition rather than nasogastric tube feeding therapy. However, patients with reduced appetite or swallowing disorders can easily become malnourished. Therefore, in medical settings, the mixed nutrition therapy is performed with a thin nutritional catheter, for example, approximately 2.5 mm in diameter, in place to prevent malnutrition while reducing the patient's discomfort during oral feeding.

[0016] On the other hand, according to "Three cases of impaired upper esophageal sphincter function after cervical esophagectomy and laryngectomy" Journal of the Japanese Society of Clinical Medicine 51(4), 699-703, 1990, Osaka City University Second Surgery Department (Chief: Professor Hiroaki Kinoshita), Tokuhara Taigo et al. (https: / / www.jstage.jst.go.jp / article / ringe1963 / 51 / 4 / 51#4#699 / #pdf / -char / en), the maximum closing pressure in the digestive tract is the pressure exerted by the upper esophageal sphincter, and is 0.020 N / mm 2 Therefore, if the maximum thickness of the tube in the direction of pressure when pressed radially with a pressure of 150 mmHg is preferably 2.5 mm or less, satisfactory oral intake is possible even with the nutrition catheter in place.

[0017] The pharyngeal pressure or esophageal pressure during oral intake varies depending on the area and individual differences, but the highest point is in the range of 50 mmHg to 300 mmHg. 2 When the maximum thickness of the tube in the pressing direction when compressed with a pressure of 50 mmHg is preferably 2.5 mm or less, more preferably 2.3 mm or less, it can be said that good oral intake is possible even with the nutrition catheter in place. Even more preferably, when the tube constituting the nutrition catheter of the present invention is compressed in the radial direction with a pressure of 50 mmHg, the maximum thickness of the tube in the pressing direction is 2.5 mm or less, more preferably 2.3 mm or less. According to this aspect, it can be said that good oral intake is possible even with the nutrition catheter in place, even in patients with the lowest pharyngeal pressure.

[0018] The thickness of the portion of the tube where the protrusion is not formed is preferably 0.6 mm or less. In this embodiment, the cross section of the tube can be deformed to be flatter by pressure due to pharyngeal pressure, intraesophageal pressure, or the like.

[0019] In the present invention, the phrase "each convex portion faces a portion of the tube where no convex portion is formed" means that, when no external force such as pressure is applied to the tube, each convex portion faces a portion of the inner circumferential surface of the tube where no convex portion is formed. In a tube cross section (transverse cross section) perpendicular to the central axis of the tube, if a line A passing through the central axis and the apex of a convex portion is the axis of symmetry of the convex portion, this means that there is no convex portion on the opposite side of the line perpendicular to the line A. Furthermore, in the present invention, the phrase "flattened" includes a reduction in height (tube diameter (thickness) in the pressing direction) and an increase in width (tube diameter (length) perpendicular to the pressing direction) due to pressing. For example, if the cross-sectional shape of a tube is circular when not pressed, this includes the tube becoming elliptical, cocoon-shaped, or the like due to pressing. It also includes further flattening of a tube that has a flat cross-sectional shape when not pressed. "Having a flat cross-sectional shape when not compressed" includes, for example, the cross-sectional shape of the tube when not compressed being elliptical, approximately elliptical, etc. Regardless of whether the cross-sectional shape of the tube when not compressed is circular, elliptical, or the like, it is preferable that the tube be easily deformed, for example, by radial pressure, and have flexibility to the extent that it does not compress the inner wall surfaces of the pharynx, esophagus, etc. If the outer diameter (height) of the tube when no radial pressure is applied is 1, it is preferable that the height be deformed to 0.9 or less by radial pressure (pressure of 150 mmHg). More preferably, it is 0.8, and even more preferably, it is 0.6 or less.

[0020] When the cross-sectional shape of the tube is circular when not compressed, the ratio of the thickness of the portion of the tube where the convex portion is not formed to the outer diameter of the tube (thickness of the portion of the tube where the convex portion is not formed / outer diameter of the tube) is preferably 0.12 or less. In this embodiment, the cross-section of the tube can be highly flattened by compression due to pharyngeal pressure or intraesophageal pressure, and a sufficient flow path for the nutrient can be ensured.

[0021] The inner diameter of the tube is preferably 2.0 mm or more and 5.0 mm or less, from the viewpoint of both reducing dysphagia and discomfort during placement and ensuring a sufficient flow path for the nutritional agent.

[0022] The height of the protrusion formed integrally with the inner circumferential surface of the tube is preferably 0.1 mm or more. If the height of the protrusion is 0.1 mm or more, it is possible to administer the nutrient by dropping it down.

[0023] In a cross section along the radial direction of the tube, the shape of the convex portion is preferably approximately triangular. In this embodiment, the cross section of the tube can be deformed to be flatter by pressure from pharyngeal pressure, intraesophageal pressure, etc., ensuring a sufficient flow path when aspirating gastric contents such as gastric juice, and the formability of the convex portion is also excellent.

[0024] The number of protrusions is preferably an odd number, more preferably 3 to 5, i.e., 3 or 5, from the viewpoint of achieving both highly flattening the cross section of the tube by pressure from pharyngeal pressure or esophageal pressure, etc., and ensuring a sufficient flow path for the nutritional supplement.

[0025] In order to ensure a sufficient flow path when aspirating stomach contents such as gastric juice, the cross-sectional area of ​​the flow path of the tube when the tube is pressed in the radial direction until the top of the convex portion abuts against a portion of the tube where the convex portion is not formed is preferably 0.5 mm. 2 That's all.

[0026] In a cross section (transverse section) along the radial direction of the tube, the total cross-sectional area of ​​the convex portions is preferably 30% or less, more preferably 10% or less, of the area of ​​a circle whose radius is the distance from the region of the inner circumferential surface of the tube where no convex portions are formed to the central axis of the tube, taken as 100%. In this embodiment, the cross section of the tube can be highly flattened by pressure from pharyngeal pressure or esophageal pressure, and a sufficient flow path for the nutritional solution can be ensured. There is no particular lower limit, but it is usually 1% or more.

[0027] The tube preferably has a two-layer structure consisting of an inner layer and an outer layer. The inner layer is made of a material with lower sliding resistance than the outer layer, and the outer layer is made of a material with higher kink resistance than the inner layer. This configuration is more advantageous than a tube made of a single material in terms of reducing the sliding resistance of the catheter placement stylet relative to the nutrition catheter and suppressing buckling of the tube.

[0028] The cross-sectional area of ​​the tube along its radial direction is preferably 1.8 mm 2 Over 7.9 mm 2 Less than or equal to 2.1 mm, more preferably 2 Over 6.6 mm 2 Less than 3.0 mm, more preferably 2 Over 5.5mm 2 In this aspect, sufficient kink resistance is provided, so that the distal end of the tube is less likely to become displaced due to peristaltic movement of the esophagus or gastroesophageal reflux disease (GERD).

[0029] The bending strength of the insertion tip of the tube is preferably 50 g or more. In this embodiment, buckling of the tube due to peristaltic movement of the esophagus or the like or friction with the digestive tract when inserting or removing the tube from the body can be suppressed.

[0030] [Nutrition Catheter] The present invention will be described in detail below, illustrating preferred embodiments. However, the present invention is not limited to the following embodiments. For the sake of convenience, the drawings referred to in the following description show simplified views of the main components constituting the embodiments of the present invention. Therefore, within the scope of the present invention, any component not shown in the drawings may be added, or any component shown in the drawings may be modified or omitted. The same components are designated by the same reference numerals in different drawings. Duplicate descriptions of such components will be omitted, and the descriptions of the preceding drawings should be taken into consideration as appropriate.

[0031] In addition, in this specification, the upper and lower limits of each numerical range can be combined in any combination, and all such combinations are considered to be described in this specification as preferred numerical ranges.

[0032] FIG. 1 is a perspective view of a nutrition catheter 1 according to one embodiment of the present invention, FIG. 2 is a perspective view of the nutrition catheter 1 as seen from the distal end of the tube 40, and FIG. 3 is a partially enlarged cross-sectional view of the nutrition catheter 1. The nutrition catheter 1 includes a tube 40 and a connector 10 provided at one end of the tube 40. In these figures, the dashed-dotted line 10a represents the central axis of the nutrition catheter 1, which is also the central axis of the tube 40 and the connector 10. The cross section in FIG. 3 is taken along the dashed-dotted line 10a. For convenience in the following description, the direction of a straight line perpendicular to the central axis 10a is referred to as the "radial direction." In the radial direction, "outside" refers to the side away from the central axis 10a, and "inside" refers to the side closer to the central axis 10a.

[0033] (Connector) The connector 10 has a connecting tube 20 at one end (first end) in the direction of the central axis 10a, and a male connector 30 at the other end (second end). The connecting tube 20 and the male connector 30 are arranged coaxially with the central axis 10a, and a flow path 11 passes through the connector 10 along the central axis 10a to connect the connecting tube 20 and the male connector 30.

[0034] 3, the connecting tube 20 has a hollow, generally cylindrical inner tube 21. The inner diameter of the inner circumferential surface 22 of the inner tube 21 gradually increases toward the tip (first end) of the connecting tube 20. The inner diameter of the portion of the inner tube 21 closest to the male connector 30 is slightly smaller than the outer diameter of the tube 40. Therefore, when the tube 40 is press-fitted into the inner tube 21, the tube 40 is fixed within the inner tube 21.

[0035] As shown in FIG. 2 , the connecting tube 20 further includes an outer peripheral wall 23 extending from a bottom surface 33 of the male connector 30 toward one end (first end) in the direction of the central axis 10a. The bottom surface 33 is a flat surface perpendicular to the central axis 10a. The outer peripheral wall 23 includes a pair of gripping surfaces 24, each of which is a substantially flat surface parallel to the central axis 10a. The pair of gripping surfaces 24 are arranged parallel to each other with the central axis 10a in between. The pair of gripping surfaces 24 make it easy for an operator to apply a rotational force to the connector 10 about the central axis 10a.

[0036] As shown in FIG. 3 , the male connector 30 includes a male luer 31 having a hollow, approximately cylindrical shape. The outer peripheral surface of the male luer 31 has a male tapered surface 32 whose outer diameter decreases toward the tip of the male luer 31. The male connector 30 further includes a roughly cylindrical outer tube 35 that is radially spaced from the male luer 31 and surrounds the male luer 31. A female thread 36 is provided on the inner peripheral surface of the outer tube 35. The male connector 30 is preferably capable of surface-contact mating (so-called tapered mating) with a stylet connector 110 (see FIG. 9A, etc.) of a catheter placement stylet (described below) used when inserting the nutrition catheter 1 into the body, or with a female connector (not shown) provided at the downstream tip of the circuit 9 of the nutrition set (see FIG. 11 ). The male connector 30 (particularly its male tapered surface 32 and female thread 36) may comply with the international standard ISO 80369-3.

[0037] The material of the connector 10 is not limited, but is preferably a hard material, such as polycarbonate, polypropylene, polyacetal, polyamide, rigid polyvinyl chloride, polyethylene, styrene-ethylene, polyethylene terephthalate, polybutylene terephthalate, or butylene-styrene block copolymer. Considering its use in medical applications and durability, polyolefin resins such as polyethylene and polypropylene are preferred. The connector 10 is preferably manufactured as a single, integrated part by injection molding the resin material.

[0038] 1 to 3, the tube 40 is fixed to the connector 10 by press-fitting the tube 40 into the inner cylinder 21. However, in the present invention, the method of fixing the tube 40 to the connector 10 is not limited to this. As long as the flow path 11 in the connector 10 can be connected to the flow path of the tube 40, the connector 10 may include a conventionally known catheter connector-to-tube connection structure. Furthermore, the connector 10 may have the same structure as a conventionally known catheter connector.

[0039] (Tube) The outer shape of the cross section (cross section along the radial direction) of the tube 40 constituting the nutrition catheter of the present invention is preferably circular when no external force is applied. The insertion tip of the tube 40 preferably has a rounded surface so as not to damage the digestive tract, etc. The tube 40 has flexibility that allows its cross section to easily deform into a flat shape due to pharyngeal pressure or esophageal pressure, etc., and does not excessively compress the inner walls of the pharynx, esophagus, etc.

[0040] As can be clearly seen from the cross-sectional view shown in Fig. 4A, the tube 40 includes a plurality of protrusions 41 integrally formed on the inner circumferential surface of the tube 40. As shown in Figs. 2 and 3, each protrusion 41 extends along the entire longitudinal length of the tube 40. When no external force is applied to the tube 40, each protrusion 41 faces a portion 42 of the tube 40 where no protrusions 41 are formed. The protrusions 41 are formed at equal intervals along the circumferential direction of the tube 40.

[0041] The inner diameter of the tube 40 is not limited, but from the viewpoint of both reducing dysphagia and discomfort during placement and ensuring a sufficient flow path for the nutritional solution, it is preferably 2.0 mm or more and 5.0 mm or less. It is more preferably 3.0 mm or more and 4.0 mm or less. In this specification, the inner diameter of the tube 40 refers to the diameter of a circle whose radius R1 is the distance from the region of the inner circumferential surface of the tube where the convex portion 41 is not formed to the central axis 10a of the tube. In this embodiment, a sufficient flow path for the nutritional solution can be ensured. If the inner diameter of the tube 40 is preferably 2.0 mm or more and 5.0 mm or less, more preferably 3.0 mm or more and 4.0 mm or less, a flow rate equivalent to or greater than that of existing nutrition catheters (e.g., 8-16 Fr, outer diameter: approximately 2.7-5.3 mm, inner diameter: approximately 1.5-4.0 mm) typically used as nasogastric feeding catheters can be ensured.

[0042] Furthermore, after nasogastric tube feeding therapy is performed, water is supplied to the lumen of the indwelling nutrition catheter to clean the lumen. This is because the supplied nutrients may be highly viscous, and the nutrition catheter will remain in the body for a certain period of time (e.g., two weeks), so if the catheter is not cleaned, there is a risk of the catheter becoming clogged. Cleaning is performed by forcefully supplying several tens of milliliters of water into the nutrition catheter using a syringe or other device. From the perspective of cleansing, a fast flow of water is preferable, but the water flow rate increases by half the inner diameter of the catheter tube 40, i.e., inversely proportional to the radius. If the inner diameter of the catheter tube 40 is 3.5 mm or less, cleaning can be performed to a level comparable to that of existing nutrition catheters (12 Fr, inner diameter approximately 3.0 mm).

[0043] The thickness T1 of the portion 42 of the tube 40 where the convex portion 41 is not formed is preferably 0.6 mm or less. This is because the cross section of the tube can be highly flattened by pressure from pharyngeal pressure, intraesophageal pressure, etc. From the viewpoint of flattening, the thickness T1 of the portion 42 of the tube 40 where the convex portion 41 is not formed is preferably 0.4 mm or less, and even more preferably 0.3 mm or less, and from the viewpoints of strength retention and formability, it is preferably 0.05 mm or more, more preferably 0.1 mm or more, and even more preferably 0.15 mm or more.

[0044] The ratio of the thickness T1 to the outer diameter of the tube 40 (thickness T1 / outer diameter of the tube) is preferably 0.120 or less, more preferably 0.10 or less, even more preferably 0.09 or less, and even more preferably 0.08 or less. In this embodiment, when pressure is applied radially to the tube 40, the cross section of the tube 40 easily flattens starting from the portion 42 where the convex portion 41 is not formed, which is advantageous for reducing dysphagia and discomfort during placement. For example, the tube 40 flattens more easily than existing nutrition catheters, which have a constant thickness along the circumferential direction. Existing nutrition catheters do not easily flatten while indwelling in a patient's body, allowing for stable administration of nutrients. The larger the inner diameter of a nutrition catheter, the less likely nutrients (especially highly viscous nutrients) will clog the flow path. However, a larger inner diameter also results in a larger outer diameter. Existing nutrition catheters with large outer diameters are disadvantageous in reducing dysphagia and discomfort during placement. Furthermore, the tube of an existing nutrition catheter has a predetermined thickness to prevent kinking and / or breakage inside the patient's body, and the ratio (wall thickness of the tube / outer diameter of the tube) is 0.13 or greater. From the viewpoint of maintaining the strength of the tube 40, the lower limit of the ratio (thickness T1 / outer diameter of the tube) is preferably 0.01 or greater, more preferably 0.03 or greater, and even more preferably 0.04 or greater.

[0045] The outer diameter of the tube 40 is preferably 15.0 mm or less, more preferably 6.2 mm or less, and even more preferably 5.0 mm or less, for the reasons of facilitating insertion into the nasal cavity and reducing discomfort caused by placement. The lower limit of the outer diameter of the tube 40 is preferably 2.1 mm or more, more preferably 3.1 mm or more, and even more preferably 3.3 mm or more, from the viewpoint of ensuring a sufficient flow path for the nutrient.

[0046] The height H1 of the protrusion 41 integrally formed on the inner circumferential surface of the tube 40, which has an inner diameter of 2.0 mm to 5.0 mm, is preferably 0.1 mm or greater, more preferably 0.2 mm or greater, and even more preferably 0.3 mm or greater. In this embodiment, even when a portion of the tube 40 along its length (typically 3 to 10 cm, corresponding to the length compressed by the pharyngeal pressure) is compressed by pharyngeal pressure (approximately 20 kPa (150 mmHg)), the drop in the tube 40 allows for the supply of nutrients at a sufficient flow rate. Specifically, for example, the tube 40 can supply nutrients at a flow rate equal to or greater than that of an existing 8 Fr (outer diameter 2.7 mm, inner diameter approximately 2.0 mm) nutrition catheter, and can supply nutrients at a flow rate equal to or greater than that of an existing 12 Fr (outer diameter 4.0 mm, inner diameter approximately 3.0 mm) catheter. The height H1 of the protrusion is based on the circumference of the circle with radius R1. The upper limit of the height H1 of the convex portion is preferably 0.6 mm or less, more preferably 0.5 mm or less, and even more preferably 0.4 mm or less, for reasons of ease of molding.

[0047] The shape of the convex portion 41 in the cross section of the tube 40 is preferably approximately triangular. In this configuration, when the tube 40 is pressed by pharyngeal pressure or the like, the cross section of the tube 40 is easily deformed into a flat shape. In addition, a sufficient flow path can be secured when aspirating stomach contents such as gastric juice. Furthermore, the tube 40 has excellent moldability.

[0048] When the shape of the convex portion 41 is approximately triangular, the preferred R (radius) at the top 43 of the convex portion 41 and the R (radius) at the base 44 of the convex portion 41 (near the area of ​​the inner surface of the tube 40 where the convex portion 41 is not formed) vary depending on the height H1 of the convex portion 41, but when the height H1 of the convex portion 41 is 0.1 to 0.6 mm, from the viewpoints of moldability and suction ability, both are preferably 0.01 mm or more and 0.3 mm or less, more preferably 0.01 mm or more and 0.2 mm or less, and even more preferably 0.05 mm or more and 0.15 mm or less.

[0049] When the shape of the convex portion 41 is approximately triangular, the angle θ at the apex 43 of the convex portion 41 varies depending on the height of the convex portion 41 and the inner diameter of the tube 40, but from the viewpoint of moldability and ensuring a sufficient flow path during suction, when the inner diameter of the tube 40 is 2.0 mm to 5.0 mm and the height of the convex portion 41 is 0.1 mm or more and 0.6 mm or less, the angle θ is preferably 40° to 160°, more preferably 60° to 140°, and even more preferably 60° to 110°. When the inner diameter of the tube 40 is 2.0 mm to 5.0 mm and the height of the convex portion 41 is 0.3 mm or more and 0.5 mm or less, the angle θ is preferably 60° to 110°.

[0050] Before supplying nutrients through the placed nutrition catheter, it is confirmed that the tip of the nutrition catheter is in the desired position. Specifically, this confirmation is performed by aspirating approximately 1 to 3 ml of stomach contents, including gastric juice, using a syringe or the like. Since this confirmation is performed every time nutrients are supplied through the nutrition catheter, it is desirable that it be performed quickly. It is desirable that the suction operation itself be completed within 30 seconds, and more preferably within 10 seconds. To achieve this, as shown in FIG. 4B, the flow path cross-sectional area S1 in the state where the tube 40 is pressed radially until the apex 43 of the convex portion 41 abuts against the portion 42 of the tube 40 where the convex portion 41 is not formed is set to 0.5 mm. 2 When the stomach contents are aspirated using a syringe or the like, the pressure inside the lumen of the tube 40 becomes negative, causing the tube 40 to deform flat. The degree of deformation of the tube 40 depends on the degree of negative pressure, but at most, the tube 40 is pressed radially until the top 43 of the convex portion 41 abuts against the portion 42 of the tube 40 where the convex portion 41 is not formed. In this state, the flow path cross-sectional area S1 is 0.5 mm 2 If the above is true, 1 ml of water can be aspirated in less than 10 seconds, and the aspirating operation can be carried out quickly.

[0051] 4B, when the tube 40 is pressed radially until the apex 43 of the convex portion 41 abuts against a portion 42 of the tube 40 where no convex portion 41 is formed, the cross section of the tube 40 is deformed flat, and a flow path 45 is secured at least between adjacent convex portions 41 according to the number of convex portions 41. The upper limit of the flow path cross-sectional area S1 is set to 3.2 mm from the viewpoint of both reducing dysphagia and discomfort during placement and securing a sufficient flow path for the nutritional agent. 2 It is preferable that the value is 2.0 mm or less. 2 It is more preferable that it is 1.0 mm or less. 2 The lower limit of the flow channel cross-sectional area S1 is 0.5 mm from the viewpoint of performing the suction operation quickly. 2 The above is more preferable.

[0052] The flow path cross-sectional area S1 can be calculated as follows. In the cross section of the tube 40 in a state where the tube 40 is pressed radially until the top 43 of the convex portion 41 abuts against the portion 42 of the tube 40 where the convex portion 41 is not formed, the total cross-sectional area of ​​the convex portions is subtracted from the cross-sectional area of ​​the tube lumen when it is assumed that the convex portion is not formed on the inner peripheral surface of the tube. The cross-sectional area of ​​the tube lumen when it is assumed that the convex portion is not formed on the inner peripheral surface of the tube is, for example, the area of ​​an ellipse. More specifically, the flow path cross-sectional area S1 can be calculated, for example, by the following formula. Flow path cross-sectional area S1 (mm 2 ) = area of ​​the ellipse (mm 2 ) - [area of ​​the convex portion (mm 2 ) × number of the protrusions]

[0053] The above-mentioned flow path cross-sectional area S1 (0.5 mm 2 Over 3.2 mm 2 To achieve this, for example, the inner diameter of tube 40 may be set to 2.0 mm or more and 5.0 mm or less, and the total cross-sectional area of ​​convex portion 41 may be set to 0.1% or more and 30% or less of the area of ​​a circle with radius R1 (see FIG. 4A). More specifically, the inner diameter of tube 40 may be set to 2.0 mm or more and 5.0 mm or less, the height H1 of convex portion 41 may be set to 0.1 mm or more and 0.6 mm or less, and θ may be set to 40° to 160°.

[0054] From the viewpoint of preventing the tube 40 from breaking during placement, a test was conducted using a method and conditions conforming to the test described in Appendix A of the JIS T3213:2018 standard. The results showed that the strength at which the catheter breaks or cracks must be 10 N or more when the outer diameter is 2.0 mm or more but less than 4.0 mm, and greater than 15 N when the outer diameter is 4.0 mm or more. Furthermore, if the kink resistance of the tube 40 is low, the tube may buckle due to peristaltic movement of the esophagus or friction with the outer periphery of the catheter during insertion and removal of the nutrition catheter, or the tip position may deviate from the desired position. Therefore, the bending strength is preferably 50 g or more. From the viewpoint of obtaining a desirable tensile strength and a desirable bending strength, the cross-sectional area of ​​the tube 40 along its radial direction is preferably 1.8 mm. 2 Over 7.9 mm 2 Less than or equal to 2.1 mm, more preferably 2 Over 6.6 mm 2 Less than 3.0 mm, more preferably 2 Over 5.5mm 2 The following is the result.

[0055] The tensile strength is measured at a chuck distance of 25 mm and a pulling speed of 500 mm / min. Other conditions are in accordance with JIS T3213:2018 Standard Appendix A.

[0056] The bending strength is the weight measured by a balance when the tube is held at a point 3 cm from the insertion end and the tube is pressed against the balance. More specifically, the bending strength is a value evaluated by the following method.

[0057] [Method for evaluating bending strength] 1. As shown in Figure 13, the tube 40 is gripped at a point 3 cm from the tip of the insertion side. 2. The tip of the insertion side of the tube 40 is pressed against the electronic balance 9 while the axis of the tube 40 from the gripped point to the tip is perpendicular to the electronic balance, and the weight is measured. 3. The weight measurement is stopped when the tube 40 buckles. 4. The maximum weight is recorded.

[0058] The "maximum weight" measured by the bending strength evaluation method is the bending strength. If the bending strength of the tube 40 is comparable to or greater than the bending strength of an existing nutrition catheter (6 Fr (outer diameter 2.0 mm)) that does not experience tip displacement issues during placement, displacement of the indwelling tube's tip can be effectively prevented. The bending strength of an existing nutrition catheter (6 Fr (outer diameter 2.0 mm)) is 50 g. Therefore, the lower limit of the bending strength of the tube 40 is preferably 50 g or greater. However, if the bending strength of the tube 40 is too high, the patient will experience increased discomfort during insertion into the body. Therefore, the bending strength is preferably 440 g or less, more preferably 360 g or less, and even more preferably 250 g or less. These upper limits of bending strength are smaller than the bending strength (440 g) of a 12 Fr nutrition catheter with a guidewire inserted into the lumen, in order to avoid adverse effects on the living body.

[0059] The maximum thickness D of the tube 40 in the pressing direction when the tube 40 is pressed in the radial direction with a pressure of 150 mmHg is set to 150 mmHg because the mixed intake can be performed with minimal discomfort even while the nutrition catheter 1 is indwelled. po is preferably 2.5 mm or less, more preferably 2.3 mm or less. It is further preferable that the maximum thickness D of the tube 40 in the pressing direction when the tube 40 is pressed in the radial direction with a pressure of 50 mmHg is po is 2.5 mm or less, more preferably 2.3 mm or less. po The lower limit of the maximum thickness D of the tube 40 in the pressing direction when the tube 40 is pressed at a pressure of 50 mmHg or 150 mmHg is usually 0.6 mm or more, more preferably 1.0 mm or more, and even more preferably 1.2 mm or more. po Specifically, is a value evaluated by the method described in the "Method for evaluating compressibility" below.

[0060] [Method for Evaluating Compressibility] 1. Connect a load cell and the upper compression jig 12 to a tensile testing machine, and place the lower compression jig 13 below the upper compression jig. 2. As shown in Fig. 14A, set the tube 40 in the gap between the upper compression jig 12 and the lower compression jig 13. 3. Lower the upper compression jig 12 at a speed of 1 mm / min, and measure the distance S between the upper compression jig 12 and the lower compression jig 13 when compressed with a pressure of 50 mmHg or 150 mmHg, i.e., the maximum thickness D of the tube 40 in the compression direction when compressed with a pressure of 50 mmHg or 150 mmHg. po The maximum thickness D of an existing 8 Fr (outer diameter 2.7 mm, inner diameter approximately 2.0 mm) nutrition catheter was measured (Fig. 14B). po is 2.51 mm, and the maximum thickness D of an existing 12 Fr (outer diameter 4.0 mm, inner diameter approximately 3.0 mm) nutrition catheter po is 3.80 mm.

[0061] One of the causes of the tip of an indwelling nutrition catheter moving from the desired position is bending of the tube 40 of the indwelling nutrition catheter in the axial direction, and bending of the tube is likely to occur in the body from the nose or mouth to the inside of the digestive tract, from the nasal cavity to the pharynx, where bending is large, particularly in the soft palate. When the kink resistance (loop length) of the tube 40 is 500 mm or less, bending of the tube 40 is effectively suppressed. The kink resistance (loop length) of the tube 40 is more preferably 300 mm or less, and even more preferably 200 mm or less. In the present invention, the kink resistance is a value evaluated by the following method.

[0062] [Kink Resistance Performance Evaluation] 1. Mark two locations on the surface of the tube 40. The distance between the pair of marks is 1,000 mm. 2. As shown in Figure 12, the two marks are overlapped to create a loop with a loop length of 1,000 mm and an inner diameter R. 3. Both ends of the tube 40 are pulled in the directions of the arrows so that the loop inner diameter R becomes smaller, and the loop length (the length of the tube 40 forming the loop) at the time when a fold occurs is measured. This loop length is used as an index of kink resistance. The smaller the value, the better the kink resistance. Note that the distance between the pair of marks may be 600 mm or less. If the length of the tube 40 is shorter than 600 mm, the distance between the pair of marks may be the maximum possible length.

[0063] The material of the tube 40 is not particularly limited, but may be at least one selected from the group consisting of polyethylene (PE), polyvinyl chloride, polypropylene, polyethylene terephthalate, polytetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, polybutadiene (PBD), polyurethane (TPU), polystyrene-based thermoplastic elastomers, urethane-based thermoplastic elastomers, and polyolefin-based thermoplastic elastomers. Because the tube 40 is placed inside the patient's body and may come into contact with the patient's body fluids, particularly gastric juice and intestinal fluid, polyethylene, polypropylene, polybutadiene, polyurethane, and the like, which are less likely to change in quality (harden, etc.) when exposed to such body fluids, are preferred.

[0064] Figures 5 to 7 show a nutritional catheter tube 40 according to another embodiment of the present invention. Three protrusions 41 are formed at equal intervals along the circumferential direction on the inner surface of the tube 40 shown in Figures 5A and 5B along the longitudinal direction of the tube 40. Each protrusion 41 faces a portion 42 of the tube 40 where no protrusions 41 are formed. The cross-sectional shape of the protrusions 41 is semicircular. An optical fiber 46 or a radiography line 47 may be embedded in any of the multiple protrusions 41. Embedding at least one of the optical fiber 46 and the radiography line 47 in the tube 40 along the entire longitudinal length of the tube 40 provides the advantage of enabling easy confirmation of the position of the tip of the placed nutritional catheter. The radiography line 47 may be formed in a linear shape from a thermoplastic resin (e.g., polypropylene) containing barium sulfate as an X-ray opaque agent. The optical fiber 47 may be insertable and removable from the protrusions 41 as needed. The cross-sectional shape of the protrusion 41 may be substantially triangular (see FIG. 4A) similar to the embodiment shown in FIGS. 4A and 4B.

[0065] Five protrusions 41 are formed at equal intervals along the circumferential direction on the inner surface of the tube 40 shown in FIGS. 6A and 6B along the longitudinal direction of the tube 40. Each protrusion 41 faces a portion 42 of the tube 40 where no protrusions 41 are formed. The cross-sectional shape of the protrusions 41 is semicircular. The tube 40 has a two-layer structure including an outer layer 40a and an inner layer 40b, and a contrast line 47 is exposed on the outside of the tube 40. A tube with such a layered structure can be manufactured using conventional molding techniques, for example, by co-extrusion molding the materials of each layer and then cooling them. The cross-sectional shape of the protrusions 41 may be approximately triangular (see FIG. 4A), similar to the embodiment shown in FIGS. 4A and 4B.

[0066] The outer layer 40a is formed from a material that can be molded into a tube that is more flexible and exhibits higher kink resistance than the inner layer 40b. The material is preferably a diene polymer, polyvinyl chloride, thermoplastic polyurethane, or other elastomer. Examples of diene polymers include 1,4-polybutadiene (PBD), 1,2-polybutadiene (PBD), polyisoprene, and styrene-butadiene block copolymers. These may be used alone or in combination. Among these, from the viewpoints of flexibility, kink resistance, and moldability, 1,4-polybutadiene or 1,2-polybutadiene are preferred, with 1,2-polybutadiene being more preferred.

[0067] The inner layer 40b is formed from a material that exhibits lower sliding resistance against the guide tool insert (described in detail below) than the material of the outer layer 40a. This material is preferably an olefin-based polymer. Examples of olefin-based polymers include polyethylenes such as high-density polyethylene (HDPE), linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), very-low-density polyethylene (VLDPE), and ultra-low-density polyethylene (ULDPE), as well as ethylene-propylene copolymers, ethylene-vinyl alcohol copolymers, and ethylene-methyl (meth)acrylate copolymers. These may be used alone or in combination. For example, among these, linear low-density polyethylene (LLDPE) and high-density polyethylene (HDPE), or a mixture thereof, are preferred, as they can reduce sliding resistance and have high bond strength with adjacent layers due to their heat-sealing properties.

[0068] In this embodiment, the tube 40 includes an outer layer 40a formed from a material that is more flexible and has higher kink resistance, and an inner layer 40b formed from a material that has low sliding resistance against the guide tool, thereby preventing the tip of the tube 40 from shifting position and making it easy to insert and remove the guide tool into the inner cavity of the tube 40.

[0069] 6A and 6B, the contrast line 47 is exposed to the outside of the tube 40 and forms part of the outer peripheral surface of the tube 40 of the nutrition catheter 1, but this is not limited thereto, and the contrast line 47 may be completely embedded inside the cylindrical wall of the tube 40, as in the embodiment of FIGS. 5A and 5B. Also, the contrast line 47 may be omitted. A contrast agent may be blended into the inner layer 40b itself.

[0070] The multiple protrusions 41 formed on the inner circumferential surface of the tube 40 do not need to be the same in size or shape. As shown in the example of the tube 40 shown in FIG. 7A , the multiple protrusions 41 may be different sizes. As shown in FIG. 7B , the protrusions 41 do not need to be solid, and may have a cavity 48 inside. As shown in FIG. 7C , the top 43 of the protrusion 41 may be a substantially flat surface facing the central axis of the tube. As shown in FIG. 7D , the cross section of the tube 40 may be substantially rectangular. Furthermore, the multiple protrusions 41 formed on the inner circumferential surface of the tube 40 may be formed at uneven intervals along the inner circumferential surface of the tube 40.

[0071] The tube 40 constituting the nutrition catheter of the present invention preferably has three or five convex portions formed on the inner surface of the tube 40 at equal intervals along the circumferential direction along the longitudinal direction of the tube 40 from the viewpoints of reducing dysphagia and discomfort during placement, ensuring a sufficient flow path for the nutrient solution, maintaining appropriate strength, preventing tip displacement, preventing buckling, performing smooth suction, and providing good washability. From the same viewpoint, the inner diameter of the tube 40 is preferably 3.0 mm or more and 4.0 mm or less, more preferably 3.3 mm or more and 3.9 mm or less. From the same viewpoint, the cross-sectional shape of the convex portions 41 is approximately triangular, with θ being 60° to 140°. From the same viewpoint, the height of the convex portions is 0.3 mm or more and 0.4 mm or less. From the same viewpoint, the thickness T1 of the portion 42 of the tube 40 where the convex portions 41 are not formed is 0.1 to 0.4 mm, and the ratio (thickness T1 / outer diameter D o From the same viewpoint, when the tube is pressed in the radial direction with a pressure of 150 mmHg, the maximum thickness D of the tube in the pressing direction is poThe outer diameter in the pressing direction is 0.6 mm or more and 2.5 mm or less. From the same viewpoint, the bending strength of the insertion side tip of the tube is 65 g or more and 360 g or less.

[0072] [Medical Device for Nasogastric Tube Feeding Therapy] In one aspect, the present invention is a medical device for nasogastric tube feeding therapy, which includes the nutrition catheter 1 of the present invention and a catheter placement stylet as a guide device. An example of a medical device for nasogastric tube feeding therapy will be described below, taking as an example a case where the catheter placement stylet is the following stylet device including a stylet connector and a guidewire (insertion body).

[0073] Fig. 9A is a perspective view showing the guide wire 150 of the stylet device 100 inserted into the nutrition catheter 1, and Fig. 9B is a cross-sectional view of Fig. 9A. Fig. 10A is a perspective view showing the stylet connector 110 of the stylet device 100 connected to the connector 10 of the nutrition catheter 1, and Fig. 10B is a cross-sectional view of Fig. 10A. The connector 10 of the nutrition catheter 1 will be referred to as the catheter connector 10 below, and the tube 40 of the nutrition catheter 1 will be referred to as the catheter tube 40 below. As the stylet device, for example, one disclosed in WO2020 / 153271 can be used.

[0074] 9A and 9B , stylet connector 110 has a first connector 120 at one end (first end) in its central axial direction, and a second connector 130 at the other end (second end). First connector 120 and second connector 130 are arranged coaxially with the central axis of stylet connector 110 and are connected via a hollow connecting tube 112. A flow path 111 passes through stylet connector 110 along the central axis to connect first connector 120 and second connector 130.

[0075] The first connector 120 is a female luer having a female tapered surface 122. The female tapered surface 122 preferably has the same diameter and taper angle as the male tapered surface 32 of the male luer 31 of the catheter connector 10 of the nutrition catheter 1 to which the stylet device 100 is adapted, so that the female tapered surface 122 can be fitted in surface contact with the male tapered surface 32 (so-called tapered fitting). The first connector 120 (particularly the female tapered surface 122) may comply with ISO 80369-3, an international standard for nutritional medical devices.

[0076] The second connector 130 further includes a male luer 131 and a substantially cylindrical outer cylinder 135 that is radially spaced from the male luer 131 and surrounds the male luer 131. A female thread 136 is provided on the inner circumferential surface of the outer cylinder 135. The second connector 130 is compatible with the male connector 30 of the catheter connector 10 provided in the nutrition catheter 1 of the present invention. The second connector 130 (particularly its male tapered surface 132 and female thread 136) may comply with the international standard ISO 80369-3.

[0077] A wire holding portion 140 is provided within the flow path 111 of the connecting tube 112 that connects the first connector 120 and the second connector 30. The wire holding portion 140 has a generally hollow cylindrical shape with a bottom, and is eccentric radially outward with respect to the central axis of the stylet connector 100. A through-hole 145 penetrates the stylet connector 100 so as to connect the inner cavity 141 of the wire holding portion 140 to the outside of the stylet connector 100. The through-hole 145 is an injection hole for filling the inner cavity 141 of the wire holding portion 140 with adhesive 148.

[0078] The guide wire 150 is disposed within the inner cavity 141 of the wire holding portion 140 so as to approach the central axis of the stylet connector 100 (preferably so as to be coaxial with the central axis of the stylet connector) and be eccentric with respect to the axis of the wire holding portion 140. The proximal end of the guide wire 150 is fixed to the stylet connector 100 via adhesive 148 filled in the inner cavity 141 of the wire holding portion 140. The guide wire 150 is led out of the first connector 120 through the flow path 111.

[0079] The guidewire 150 is a long, thin, string-like object that has appropriate flexibility (or pliability) so that it can be bent and deformed by an external force. The guidewire 150 is inserted into the catheter tube 40 of the nutrition catheter 1 to improve the rigidity (elasticity) of the catheter tube 40 and prevent kinking. The outer diameter of the guidewire 150 is smaller than the inner diameter of the catheter tube 40. There are no limitations on the configuration of the guidewire 150, and it may be the same as the configuration of known guidewires used in nasogastric and enteral nutrition catheters. For example, the guidewire 150 may be a stranded wire made by twisting together elemental wires. There are no limitations on the material of the elemental wires, and they may be metals such as stainless steel or relatively high-rigidity (high-elasticity) resins such as nylon or polyester.

[0080] [Method of Using the Nutrition Catheter and Medical Device for Nasogastric Tube Feeding Therapy] Using Figs. 9 to 11, a method of using an example of the medical device for nasogastric tube feeding therapy of the present invention will be described.

[0081] As shown in FIGS. 9A and 9B, before inserting the nutrition catheter 1 into the body, the guide wire 150 of the stylet device 100 is inserted into the catheter tube 40, and the stylet connector 110 is connected to the catheter connector 10.

[0082] Figure 10A is a perspective view showing the stylet connector 110 of the stylet device connected to the catheter connector 10 of the nutrition catheter 1, and Figure 10B is a cross-sectional view thereof. The male luer 31 of the catheter connector 10 is inserted into the first connector (female luer) 120 of the stylet connector 110. The first connector 120 is inserted into the gap between the male luer 31 and the outer tube 35. The female tapered surface 122 of the first connector 120 and the male tapered surface 32 of the male luer 31 have the same diameter and taper angle. Therefore, the female tapered surface 122 and the male tapered surface 32 make surface contact and engage liquid-tightly (so-called tapered engagement). This type of connection between the first connector 120 and the male luer 31 is generally referred to as a "slip connection." The flow path 111 of the stylet connector 110, the flow path 11 of the catheter connector 10, and the lumen of the catheter tube 40 are sequentially connected. The guide wire 150 is inserted into the flow path 11 and the lumen of the catheter tube 40. Although not shown, the tip (distal end) of the guide wire 150 reaches the tip (distal end) of the catheter tube 40 or its vicinity.

[0083] 10A and 10B , with the stylet connector 110 connected to the catheter connector 10, the tip (not shown) of the catheter tube 40 is inserted into the patient's nasal cavity. The tube 40 has increased rigidity (elasticity) due to the guide wire 150 inserted therein. This is advantageous in allowing the tip of the catheter tube 40 to reach a desired location (e.g., the stomach or small intestine).

[0084] Whether the tip of the catheter tube 40 has reached the desired position can be confirmed, for example, by aspirating gastric juice or injecting air through the catheter tube 40. Aspirating gastric juice or injecting air can be performed by connecting, for example, a syringe to the second connector 130 (particularly its male luer 131) of the stylet connector 110. Once it has been confirmed that the tip of the catheter tube 40 has reached the desired position, the stylet connector 110 is separated from the catheter connector 10, and the guidewire 150 is pulled out from the catheter tube 40. The stylet device 100 is separated from the nutrition catheter 1. Meanwhile, the nutrition catheter 1 is placed in the patient. The proximal end of the placed nutrition catheter 1 is fixed to the patient's face with tape or the like. In this state, the patient orally ingests breakfast, lunch, and dinner.

[0085] When oral nutrition is insufficient, nasogastric tube feeding therapy is performed, for example, after dinner. Specifically, the tape is removed from the patient, and a nutrition set including a nutrition bottle 8 and a circuit 9 is connected to the indwelling nutrition catheter 1, as shown in Figure 11. A female connector (not shown) provided at the tip of the circuit 9 is connected to the male connector 30 of the nutrition catheter 1 (see Figure 9A, etc.) by, for example, surface contact fitting (so-called tapered fitting) and screwing using a female thread 36. Nutrients (liquid) are then supplied to the patient via the circuit 9 and nutrition catheter 1 by gravity flow.

[0086] After the administration of nutrients by nasogastric tube feeding therapy is completed, water or the like is supplied to the lumen of the nutrition catheter 1 to wash the lumen.

[0087] The above-described embodiment is merely an example, and the present invention is not limited to the above-described embodiment, and can be modified as appropriate.

[0088] The cross-sectional shape of the convex portion 41 formed integrally on the inner peripheral surface of the catheter tube 40 and extending along the longitudinal direction of the catheter tube 40 may be any of a substantially triangular, semicircular, semi-elliptical, substantially trapezoidal, etc. As long as the convex portion 41 faces the portion 42 of the catheter tube 40 where no convex portion 41 is formed, there is no particular limitation on the number of convex portions 41, and the number may be one or an even number.

[0089] The guide wire (insertion body) constituting the stylet device may be a hollow or solid resin tube having a higher bending strength than the catheter tube 40 constituting the nutrition catheter. An optical fiber may be embedded in the cylindrical wall or inside of the tube.

[0090] Hereinafter, the present disclosure will be described in more detail with reference to examples, but these are merely illustrative examples and the present disclosure is not limited to these examples.

[0091] (Example 1) Figure 8A is a cross-sectional view of a catheter tube 40 constituting a nutrition catheter according to yet another embodiment of the present invention. Five convex portions 41 are formed on the inner circumferential surface of the catheter tube 40 at equal intervals along the circumferential direction along the longitudinal direction of the catheter tube 40. Each convex portion 41 faces a portion 42 where no convex portion is formed when no external force is applied. The height H1 of the convex portion 41 is 0.35 mm. The cross-sectional shape of the convex portion 41 is approximately triangular, and the radius R (radius) at the apex 43 of the convex portion 41 and the radius R (radius) at the base portion 44 of the convex portion (near the region of the inner circumferential surface of the catheter tube 40 where no convex portion 41 is formed) are both 0.1 mm, and θ is 100°. The outer diameter D of the catheter tube 40 o The thickness T1 of the portion 42 of the catheter tube 40 where the convex portion 41 is not formed is 0.21 mm, and the ratio (thickness T1 / outer diameter D o ) is 0.05, the radius R is 1.87 mm, and the inner diameter of the catheter tube 40 is 3.74 mm. When no external force is applied to the catheter tube 40, the cross-sectional area of ​​the flow path is 10.16 mm 2This flow path cross-sectional area is larger than that of an existing 12 Fr nutrition catheter and smaller than that of an existing 16 Fr nutrition catheter. The total cross-sectional area of ​​the convex portion 41 is 7.68% of the area of ​​a circle with radius R1. The catheter tube 40 has a two-layer structure including an outer layer 40a and an inner layer 40b, with the outer layer 40a made of 1,2-polybutadiene and the inner layer 40b made of linear low-density polyethylene (LLDPE).

[0092] The cross-sectional area of ​​the catheter tube 40 along the radial direction is 3.43 mm 2 The catheter tube 40 has a tensile strength of 46.17 N and a bending strength of 229 g. The tensile strength of the catheter tube 40 of this embodiment is higher than the tensile strength (37 N) of an existing 10 Fr nutrition catheter. Furthermore, the bending strength of the catheter tube 40 is higher than the bending strength (179.14 g) of an existing 10 Fr nutrition catheter, but is significantly lower than the bending strength (440 g) of a 12 Fr nutrition catheter with a guidewire inserted into the lumen. Therefore, the catheter tube 40 of this embodiment has sufficient strength to prevent breakage during use. Use of the catheter tube 40 of this embodiment prevents displacement of the tip of the catheter tube during placement and reduces discomfort to the patient during insertion into the body.

[0093] As shown in FIG. 14, the maximum thickness D of the catheter tube 40 in the pressing direction when pressed from the radial direction with a pressure of 20 kPa (150 mmHg, equivalent to pharyngeal pressure) according to the above-mentioned [Method for evaluating compressibility]. po The thickness was 1.98 mm. This is less than the thickness of an existing 8 Fr nutritional catheter tube when compressed under the same conditions. Therefore, by using the catheter tube 40 of this embodiment, it is possible to reduce the difficulty and discomfort of swallowing during placement of the nutritional catheter, and mixed intake can be performed without difficulty.

[0094] Furthermore, when the nutrition catheter was placed on a horizontal table so that it was 50 cm above the nutrition bottle, and a portion of the catheter tube 40 (5 cm, corresponding to the length compressed by pharyngeal pressure) was pressed radially with a pressure of 20 kPa (150 mmHg, corresponding to pharyngeal pressure), nutrients (Ecoflow Aqua, manufactured by Clinico) were supplied from the nutrition bottle. The flow rate of the nutrients in the nutrition catheter was 0.90 g / min. This is a higher flow rate than the flow rate of 0.19 g / min of an existing 8 Fr nutrition catheter. Therefore, it was confirmed that the use of the catheter tube of this embodiment ensures a sufficient flow path for the nutrients.

[0095] As shown in FIG. 8B, when the catheter tube 40 is pressed radially until the top 43 of the convex portion 41 abuts against the portion 42 of the inner circumferential surface of the tube 40 where no convex portion is formed, the flow path cross-sectional area S1 of the catheter tube 40 is 1.42 mm 2 When water was aspirated using the catheter tube of this embodiment, 1 ml of water could be aspirated in less than 10 seconds, confirming that the aspirating operation can be performed quickly. Water was aspirated using a 20 cc syringe connected to the catheter connector.

[0096] (Examples 2 to 6) Nutrition catheters were produced in Examples 2 to 6. The material, outer diameter, inner diameter, and radius R of the catheter tube constituting each nutrition catheter were 1 , the thickness T of the part where the protrusion is not formed 1 , ratio (thickness T 1 / outer diameter), cross-sectional area of ​​the nutrition catheter tube, number of convex parts, height of the convex parts, θ, radius R 1 The ratio of the total cross-sectional area of ​​the convex portions to the area of ​​the circle, and the flow path cross-sectional area S1, were as shown in Table 1 below.

[0097] (Comparative Examples 1 and 2) An 8 Fr commercially available nutrition catheter (manufactured by JMS) was prepared as the nutrition catheter of Comparative Example 1, and a 12 Fr commercially available nutrition catheter (manufactured by JMS) was prepared as the nutrition catheter of Comparative Example 2. In Table 1, the flow path cross-sectional area S of the nutrition catheters of Comparative Example 1 and Comparative Example 2 is 1is the cross-sectional area (transverse section) of the tube lumen when the catheter tube constituting the nutrition catheter is pressed radially with a pressure of 150 mmHg (equivalent to pharyngeal pressure). The cross-sectional area (transverse section) of the tube lumen was calculated by subtracting the wall thickness of the tube from the maximum thickness of the catheter tube when the catheter tube is pressed radially with a pressure of 150 mmHg (equivalent to pharyngeal pressure), using the value as the length of the minor axis of the ellipse.

[0098] For the nutritional catheters of Examples 2 to 6, the time required to aspirate 1 ml of water was measured in the same manner as in Example 1. The results are shown in Table 1.

[0099]

[0100] The cross-sectional areas (transverse cross sections) along the radial direction of the catheter tubes constituting the nutritional catheters of Examples 2 to 6 are as shown in Table 1. The tensile strength (34.00 N to 146.12 N) of the catheter tubes constituting the nutritional catheters of Examples 2 to 6 is equal to or greater than the tensile strength (37 N) of an existing 10 Fr nutritional catheter. Furthermore, the bending strength (203.9 g to 308 g) of the catheter tubes is sufficiently higher than the bending strength (50 g) of an existing 6 Fr nutritional catheter, but is significantly lower than the bending strength (440 g) of a 12 Fr nutritional catheter with a guidewire inserted into the lumen. Therefore, the nutritional catheters of Examples 2 to 6 have sufficient strength to prevent breakage during use. Use of the nutritional catheters of Examples 2 to 6 prevents displacement of the catheter tube tip during placement and reduces patient discomfort during insertion into the body.

[0101] The catheter tubes constituting the nutrition catheters of Examples 2 to 6 were subjected to the above-mentioned "Method for evaluating compressibility" to measure the maximum thickness D when compressed from the radial direction with a pressure of 20 kPa (150 mmHg, equivalent to pharyngeal pressure). po From this, it was confirmed that, like the nutritional catheter of Example 1, the nutritional catheters of Examples 2 to 6 were able to reduce the difficulty in swallowing and discomfort during placement, and that mixed intake could be performed without difficulty.

[0102] As with the nutritional catheter of Example 1, a water suction test was conducted on the nutritional catheters of Examples 2 to 6, and it was confirmed that the suction operation could be performed quickly in all cases. Industrial application fields

[0103] The nasogastric tube feeding catheter of the present invention can reduce the difficulty in swallowing and discomfort during placement while ensuring a sufficient flow path for nutrients, making it useful for mixed intake, where nutrition is taken orally (meals) as the basis and nutritional deficiencies are supplemented with nasogastric tube feeding therapy.

[0104] DESCRIPTION OF SYMBOLS 1 Nutrition catheter 10 Connector (catheter connector) 40 Tube (catheter tube) 40a Outer layer 40b Inner layer 41 Convex portion 42 Portion of tube where convex portion is not formed 43 Top of convex portion 44 Base of convex portion 45 Flow path T1 Thickness of portion of tube where said convex portion is not formed R1 Radius of tube inner diameter

Claims

1. A nasoenteric feeding catheter comprising a tube and a connector provided at one end of the tube, wherein the tube includes a plurality of convex portions integrally formed on the inner peripheral surface of the tube and extending along the longitudinal direction of the tube, each convex portion faces a portion of the tube where the convex portion is not formed, and the portion of the tube where the convex portion is not formed can be bent by pharyngeal pressure or esophageal pressure so that the cross section of the tube can be deformed into a flat shape.

2. The nasoenteric feeding catheter according to claim 1, wherein the thickness of the portion of the tube where the convex portion is not formed is 0.6 mm or less.

3. The nasoenteric feeding catheter according to claim 1 or 2, wherein the ratio (thickness / outer diameter) of the thickness of the portion of the tube where the convex portion is not formed to the outer diameter of the tube is 0.12 or less.

4. The nasoenteric feeding catheter according to any one of claims 1 to 3, wherein the inner diameter of the tube is 2.0 mm or more and 5.0 mm or less.

5. The nasoenteric feeding catheter according to any one of claims 1 to 4, wherein the height of the convex portion is 0.1 mm or more.

6. The nasoenteric feeding catheter according to any one of claims 1 to 5, wherein in a cross section along the radial direction of the tube, the shape of the convex portion is substantially triangular.

7. The nasoenteric feeding catheter according to any one of claims 1 to 6, wherein the number of the convex portions is an odd number and is 3 or more and 5 or less.

8. The cross-sectional area of the flow path of the tube in a state where the tube is radially pressed until the top of the convex portion contacts a portion of the inner peripheral surface of the tube where the convex portion is not formed is 0.5 mm 2 or more. The transnasal transesophageal nutritional catheter according to any one of claims 1 to 7.

9. The nasoenteric feeding catheter according to any one of claims 1 to 8, wherein in a cross section along the radial direction of the tube, the total cross-sectional area of the convex portions is 30% or less when the area of a circle with the distance from the region of the inner peripheral surface of the tube where the convex portion is not formed to the central axis of the tube as the radius is taken as 100%.

10. The nasoenteric feeding catheter according to any one of claims 1 to 9, wherein the tube has a two-layer structure composed of an inner layer and an outer layer, the inner layer is made of a material with lower sliding resistance than the outer layer, and the outer layer is made of a material with higher kink resistance than the inner layer.

11. The cross-sectional area along the radial direction of the tube is 1.8 mm 2 or more and 7.9 mm 2 or less. The transnasal enteral nutrition catheter according to any one of claims 1 to 10.

12. The nasoenteric feeding catheter according to any one of claims 1 to 11, wherein when the tube is radially pressed at a pressure of 150 mmHg, the maximum thickness of the tube in the pressing direction is 2.5 mm or less.

13. The nasal trans-tracheal nutrition catheter according to any one of claims 1 to 12, wherein the bending strength of the insertion-side tip of the tube is 50 g or more.

14. A medical device for nasal trans-tracheal nutrition therapy, comprising the nasal trans-tracheal nutrition catheter according to any one of claims 1 to 13 and a guiding device, wherein the guiding device includes an insertion body that has a higher bending strength than the tube constituting the nasal trans-tracheal nutrition catheter and can be inserted into and removed from the lumen of the nutrition catheter.

15. The medical device for nasal trans-tracheal nutrition therapy according to claim 14, wherein the guiding device is a stylet for catheter retention, and includes a guide wire as the insertion body and a stylet connector provided at the proximal end of the guide wire.

16. The medical device for nasal trans-tracheal nutrition therapy according to claim 14, wherein the insertion body includes an optical fiber.

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