JP2019050861A - Baloon catheter, and manufacturing method thereof - Google Patents

Abstract

To provide a balloon catheter capable of expanding a balloon easily, and contracting it surely; and to provide a manufacturing method thereof.SOLUTION: There is provided a balloon catheter 1 including a resin film 3 constituting an expandable/contractible baloon 5 on the outer peripheral surface 2s of a catheter shaft 2. In the balloon catheter, the catheter shaft has a lumen 4 which is a passage for liquid, and an inflation lumen 6 which is a passage for fluid for adjusting a baloon pressure, and two or more open holes 7A, 7B through which the fluid is circulated between the baloon and the inflation lumen are formed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a balloon catheter and a manufacturing method thereof.

  Conventionally, balloon catheters inserted into blood vessels and urethra are used as medical instruments. A balloon catheter for inserting a blood vessel is used for the purpose of expanding a blood vessel by inflating the balloon. The balloon catheter for urethral insertion is used for the purpose of indwelling the distal end portion of the catheter in the bladder by inflating the balloon in the bladder. In any balloon catheter, after use, the balloon is deflated and removed from the blood vessel or urethra.

  The structure of the balloon catheter mainly includes a catheter shaft and a balloon at the distal end thereof. In the balloon catheter described in Patent Document 1, the catheter shaft has a double tube structure composed of an inner tube and an outer tube, and the tip of the inner tube protrudes from the tip of the outer tube. When viewed in the tube axis direction, the distal end of the balloon is bonded to the distal end of the inner tube, and the proximal end of the balloon is bonded to the distal end of the outer tube. The inner pipe is a liquid flow path (lumen) through which chemicals and body fluids flow, and the area other than the inner pipe in the outer pipe is a flow path (inflation lumen) through which a pressure fluid that adjusts the balloon pressure flows. is there. By injecting distilled water into the inflation lumen from the proximal end side of the balloon catheter, the balloon is inflated with distilled water released from the distal end of the outer tube. Further, after use, the balloon is deflated by discharging distilled water in the balloon from the proximal end side of the balloon catheter through the inflation lumen.

Japanese Patent No. 5201240

  However, when the outer diameter of the inner tube constituting the double-tube structure of the catheter shaft becomes closer to the inner diameter of the outer tube, when a stress such as twisting or bending is applied to the catheter shaft, a crescent-shaped or annular inflation lumen May partially occlude and prevent balloon inflation and deflation.

  The present invention provides a balloon catheter that can easily inflate and reliably deflate a balloon, and a method for manufacturing the same.

  As a result of studying the above problems, the present inventors have found that, in applications where the outer diameter of the catheter shaft is required to be reduced (for example, for insertion into a small-diameter blood vessel or urethra), one inflation lumen and one lumen are used. It was considered desirable to use a catheter shaft formed as two independent flow paths in the tube. Such an integral catheter shaft can be manufactured by extrusion.

  Therefore, the present inventors formed one through hole from the outer peripheral surface to the inflation lumen at the distal end portion of the integrally formed catheter shaft, and then attached the distal end portion including the through hole to a stretchable resin. A plurality of balloon catheters coated with a coating film were manufactured. Distilled water was injected from the proximal end into the inflation lumens of these prototypes, and the balloon could be inflated as desired. However, in some cases, the balloon cannot be deflated by discharging distilled water in the balloon from the proximal end side of the inflation lumen in order to deflate the balloon.

  As a result of further investigations, the present inventors have completed the present invention, which is a balloon catheter that can easily inflate and reliably deflate the balloon, and a manufacturing method thereof. That is, the present invention is as follows.

[1] A balloon catheter having a resin film constituting a balloon that can be inflated and deflated on the outer peripheral surface of the catheter shaft, wherein the catheter shaft adjusts a lumen that is a liquid flow path and a pressure of the balloon A balloon catheter having an inflation lumen which is a flow path of a fluid to be fluidized, wherein two or more through holes through which the fluid flows between the balloon and the inflation lumen are formed.
[2] The balloon catheter according to [1], wherein an outer diameter of the catheter shaft is 2.0 mm or less.
[3] The balloon catheter according to [1] or [2], wherein the thickness of the resin film when the balloon is deflated is 0.3 mm or less.
[4] The balloon catheter according to any one of [1] to [3], wherein the volume of the fluid accommodated in the balloon is 2 ml or less.
[5] The balloon catheter according to any one of [1] to [4], wherein a distance between adjacent through holes among the two or more through holes is 1 mm or more and 10 mm or less.
[6] The balloon catheter according to any one of [1] to [5], wherein the resin film is formed of silicone rubber.
[7] The balloon catheter according to any one of [1] to [6], which is used for inserting a small animal into the urethra.
[8] A method of manufacturing a balloon catheter having a resin film constituting a balloon that can be expanded and contracted on the outer peripheral surface of the catheter shaft, the lumen being a liquid flow path, and the fluid for adjusting the pressure of the balloon And a step of forming two or more through holes penetrating from the outer peripheral surface of the catheter shaft to the inflation lumen; and an outer peripheral surface of the catheter shaft. And a step of covering at least the region in which the two or more through-holes are formed with the resin film.

In the balloon catheter of the present invention, the balloon can be easily inflated and the balloon can be reliably deflated.
According to the balloon catheter manufacturing method of the present invention, it is possible to manufacture a balloon catheter that can be easily inflated and surely deflated.

In an example of a balloon catheter of the present invention, it is a mimetic diagram showing a state at the time of inflation of a balloon. In an example of the balloon catheter of the present invention, it is a mimetic diagram showing a state at the time of balloon contraction. It is sectional drawing cut | disconnected by the cross section orthogonal to an axial direction by the AA line of FIG. It is a schematic diagram which shows an example of the manufacturing method of the balloon catheter of this invention, (a) shows a mode that a through-hole is formed, (b) shows a mode that a mold release layer was formed, (c) is a resin film The state of forming is shown. It is a photograph of an example of the balloon catheter concerning this invention manufactured in the Example.

《Balloon catheter》
A first aspect of the present invention is a balloon catheter provided with a resin film constituting a balloon capable of expanding and contracting on an outer peripheral surface of a catheter shaft, wherein the catheter shaft includes a lumen which is a liquid flow path, An inflation lumen, which is a fluid flow path for adjusting the pressure of the balloon, wherein two or more through-holes through which the fluid flows between the balloon and the inflation lumen are formed. .

  A balloon catheter 1 which is an example of this embodiment is shown in FIG. The balloon catheter 1 has a catheter shaft 2 and a resin film 3 that covers the outer peripheral surface 2s of the distal end portion 2a.

  The catheter shaft 2 includes a lumen 4 serving as a liquid flow path through which a liquid L1 such as a body fluid such as urine and blood or a solution (medicine solution) containing a drug, and a pressure of a balloon 5 formed by the resin film 3 expanding. And an inflation lumen 6 through which the pressure fluid L2 passes. The lumen 4 and the inflation lumen 6 are independent flow paths, and are parallel to each other along the longitudinal direction of the catheter shaft 2. The end (opening) 6a on the distal end side of the inflation lumen 6 is closed by heat sealing or resin filling.

  Between the first end portion 5a on the distal side of the balloon 5 and the second end portion 5b on the proximal side of the balloon 5, the first through hole 7A and the second through hole that penetrate the inflation lumen 6 from the outer peripheral surface 2s. A hole 7B is formed.

When the pressure fluid L2 is injected from the opening 6b on the proximal end side of the inflation lumen 6 with a syringe or the like, the pressure fluid L2 is injected into the balloon 5 through the first through hole 7A and the second through hole 7B. Here, since the resin film 3 has stretchability, the balloon 5 expands as the pressure increases, and its volume increases (FIG. 1).
On the contrary, when the pressure fluid L2 is sucked from the opening 6b with a syringe or the like, the pressure fluid L2 is discharged from the balloon 5 through the first through hole 7A and the second through hole 7B. Here, since the resin film 3 has elasticity, the balloon 5 contracts as the pressure decreases, the volume of the balloon 5 decreases, and finally, the resin film 3 covers the outer peripheral surface 2s of the catheter shaft 2 (see FIG. 2).

<Effect>
In the balloon catheter of the present invention, two or more through-holes penetrating from the outer peripheral surface of the catheter shaft to the inflation lumen are provided. By providing two or more through-holes, the balloon can be reliably inflated and deflated as intended.
On the other hand, when only one through hole is provided, the pressure fluid cannot be completely discharged from the balloon, and the balloon is often not completely deflated as intended.
As described above, the reason why the balloon catheter of the present invention has excellent operability is as follows. That is, even if the resin film constituting the balloon blocks one through hole in the initial to middle stage when the balloon is contracting, the remaining pressure fluid can be discharged by one or more remaining through holes. Is prevented from stopping on the way.

  According to said mechanism, the number of the said through-holes of a catheter shaft should just be 2 or more, 3 or more are preferable and 4 or more are more preferable. However, the balloon of the balloon catheter manufactured by the method to be described later has a “navel” that protrudes into the inner space of the balloon according to the number of through holes. The navel is a protrusion of the resin film constituting the balloon, which affects the shape of the balloon when it is inflated, and may cause an irregularity. In addition, the balloon may be torn around the navel at the time of overexpansion. Therefore, although the number of through holes depends on the size of the balloon, it is preferably 10 or less, more preferably 8 or less, and even more preferably 5 or less.

  The thickness (diameter) of the through-hole is appropriately set according to the outer diameter of the catheter shaft, and can be set, for example, approximately equal to the outer diameter of the lumen serving as the liquid flow path or the outer diameter of the inflation lumen. The thickness of each through-hole may be the same as each other or different.

FIG. 3 shows a cross section perpendicular to the longitudinal direction of the catheter shaft 2 of the balloon catheter 1 (cross section taken along line AA in FIG. 2). Here, the thickness of the resin film 3 covering the outer peripheral surface 2s is not considered. When the shape of the outer edge of the cross section of the catheter shaft 2 is circular, the diameter (outer diameter) R1 is preferably 0.50 mm or more and 2.00 mm or less, more preferably 0.50 mm or more and 1.50 mm or less, and 0.50 mm. More preferably, it is 1.00 mm or less.
When the outer diameter R1 is 0.50 mm or more, the flow resistance of the lumen 4 and the inflation lumen 6 can be suppressed from becoming excessively high.
When the outer diameter R1 is 2.00 mm or less, the outer diameter R1 is more suitable for use in insertion into a small diameter blood vessel or urethra. In the case of use for insertion into the urethra (foley catheter), the thinner the outer diameter, the more pain can be reduced during insertion. Moreover, when applied to small animals such as cats and dogs, the urethra is thinner than humans, so it is difficult to apply the outer diameter of a conventional Foley catheter for humans, and the outer diameter R1 is set to 1.50 mm or less. The balloon catheter according to the present invention is particularly useful.
When a release layer 8 described later is formed on the outer peripheral surface 2s of the catheter shaft 2, the thickness of the release layer 8 is also included in the diameter R1 of the catheter shaft 2. Note that the release layer 8 is not shown in FIG.

  The outer diameter of the balloon catheter of the present invention is the smallest circle (minimum circle) including the outer peripheral edge of the cross section orthogonal to the longitudinal direction of the catheter shaft, and is 5 in the region where the resin film forming the balloon is formed. The arithmetic average of the values measured in the cross section of the location. The shape of the outer peripheral edge of the catheter shaft in the cross section is not particularly limited, and examples thereof include a circle, an ellipse, a rectangle, and other polygons. The diameter of the minimum circle is the diameter of the circle when the outer peripheral edge of the cross section is circular, and the long diameter of the ellipse when the outer peripheral edge of the cross section is an ellipse. The minimum circle and its diameter can be obtained by image processing of the arbitrary five cross sections.

In the cross section illustrated in FIG. 3, the diameter (outer diameter) R2 of the lumen 4 serving as the liquid flow path is preferably 0.10 mm or more and 0.50 mm or less, more preferably 0.15 mm or more and 0.40 mm or less. More preferably, it is 20 mm or more and 0.30 mm or less.
When the outer diameter R2 is 0.10 mm or more, the flow resistance of the lumen 4 can be suppressed from becoming excessively high, and the inflation and deflation of the balloon can be easily controlled with an appropriate pressure.
When the outer diameter R2 is 0.50 mm or less, the outer diameter R2 is more suitable for use in insertion into a small-diameter blood vessel or urethra.

  The outer diameter of the lumen serving as the liquid flow path of the balloon catheter of the present invention is the smallest circle (minimum circle) diameter including the outer peripheral edge of the lumen in the cross section orthogonal to the longitudinal direction of the catheter shaft. The arithmetic average of the values measured at arbitrary five cross sections (excluding the cross section including the through hole) in the region where the resin film is formed. The shape of the outer peripheral edge of the lumen in the cross section is not particularly limited, and examples thereof include a circle, an ellipse, a rectangle, and other polygons. The diameter of the minimum circle is the diameter of the circle when the outer peripheral edge is circular, and the major axis of the ellipse when the outer peripheral edge is an ellipse. The minimum circle and its diameter can be obtained by image processing of the arbitrary five cross sections.

In the cross section illustrated in FIG. 3, the diameter (outer diameter) R3 of the inflation lumen 6 serving as a flow path for the pressure fluid is preferably 0.10 mm or more and 1.50 mm or less, and more preferably 0.15 mm or more and 1.00 mm or less. 0.20 mm or more and 0.50 mm or less is more preferable.
When the outer diameter R3 is 0.10 mm or more, the flow resistance of the inflation lumen 6 can be suppressed from becoming excessively high, and a pressure fluid such as water or air can be easily circulated.
When the outer diameter R3 is 1.50 mm or less, the outer diameter R3 is more suitable for use in insertion into a small-diameter blood vessel or urethra.

  The outer diameter of the inflation lumen of the balloon catheter of the present invention is the smallest circle (minimum circle) including the outer periphery of the inflation lumen in the cross section perpendicular to the longitudinal direction of the catheter shaft. The arithmetic average of values measured at arbitrary five cross sections in the formed region is used. The shape of the outer peripheral edge of the inflation lumen in the cross section is not particularly limited, and examples thereof include a circle, an ellipse, a rectangle, and other polygons. The diameter of the minimum circle is the diameter of the circle when the outer peripheral edge is circular, and the major axis of the ellipse when the outer peripheral edge is an ellipse. The minimum circle and its diameter can be obtained by image processing of the arbitrary five cross sections.

In the cross section illustrated in FIG. 3, the thickness of the partition wall separating the lumen 4 and the inflation lumen 6, that is, the separation distance between the outer peripheral edge of the lumen 4 and the outer peripheral edge of the inflation lumen 6 is 0.01 mm or more and 0 .10 mm or less is preferable, 0.02 mm or more and 0.09 mm or less is more preferable, and 0.03 mm or more and 0.08 mm or less is more preferable.
When the value is equal to or greater than the lower limit of the above range, the independence of the lumen 4 and the inflation lumen 6 is sufficiently maintained, and communication with each other can be prevented.
The lumen 4 and the inflation lumen 6 can be sufficiently brought close to each other if the upper limit of the above range is exceeded, and the outer diameter R1 of the catheter shaft can be reduced.
The thickness of the partition wall (the separation distance) is a distance in which the outer peripheral edge of the inflation lumen and the outer peripheral edge of the lumen are closest to each other in a cross section perpendicular to the longitudinal direction of the catheter shaft, in the region where the resin film forming the balloon is formed. The arithmetic mean of the values measured at any five cross-sections.

In the cross section illustrated in FIG. 3, the thickness of the partition wall separating the inflation lumen 6 and the outer peripheral surface 2s of the catheter shaft, that is, the separation distance of the portion where the outer peripheral edge of the inflation lumen 6 is closest to the outer peripheral surface 2s is 0.03 mm. The thickness is preferably 0.15 mm or less, more preferably 0.05 mm or more and 0.12 mm or less, and further preferably 0.07 mm or more and 0.10 mm or less.
If it is at least the lower limit of the above range, the inflation lumen 6 can be kept stable, and the occurrence of external tearing (leakage) can be prevented.
When it is at least the upper limit of the above range, it is easy to set the outer diameter R2 of the inflation lumen 6 to be large while keeping the outer diameter R1 of the catheter shaft 2 small.
The thickness of the partition wall (the separation distance) is a distance in which the outer peripheral edge of the inflation lumen and the outer peripheral surface of the catheter shaft are closest to each other in a cross section perpendicular to the longitudinal direction of the catheter shaft. The arithmetic average of the values measured at any of the five cross sections (excluding the cross section including the through hole).

In the cross section illustrated in FIG. 3, the thickness of the partition wall that separates the lumen 4 that is the liquid channel and the outer peripheral surface 2 s of the catheter shaft, that is, the separation distance of the portion where the outer peripheral edge of the lumen 4 is closest to the outer peripheral surface 2 s is 0.04 mm or more and 0.20 mm or less is preferable, 0.06 mm or more and 0.15 mm or less is more preferable, and 0.08 mm or more and 0.12 mm or less is more preferable.
The lumen 4 is kept stable when it is at least the lower limit of the above range, and it is possible to prevent the occurrence of tearing (leakage) to the outside.
When it is at least the upper limit of the above range, it is easy to set the outer diameter R3 of the lumen 4 to be large while keeping the outer diameter R1 of the catheter shaft 2 small.
The thickness of the partition wall (the separation distance) is a distance in which the outer peripheral edge of the lumen and the outer peripheral surface of the catheter shaft are closest to each other in a cross section orthogonal to the longitudinal direction of the catheter shaft, in the region where the resin film forming the balloon is formed. The arithmetic mean of the values measured at any five cross-sections.

  The lumen 4 that is the liquid flow path of the balloon catheter 1 is not limited to one, and may be two or more depending on the application. From the viewpoint of reducing the outer diameter R1 of the balloon catheter 1 and increasing the outer diameter R3 of the lumen 4, it is preferable that the number of the lumen 4 is one.

  As a constituent material of the catheter shaft 2, a resin capable of forming the flexible catheter shaft 2 is preferable, and examples thereof include resin materials applied to known catheter shafts such as silicone and latex. Among these, silicone having excellent biocompatibility is preferable, and rubbery silicone rubber exhibiting rubber elasticity at room temperature is more preferable.

  The outer peripheral surface 2s of the catheter shaft 2 may be subjected to a known surface treatment for a silicone or plastic molded product. Specific examples of the surface treatment include plasma treatment, corona treatment, alkali treatment, acid treatment, hydrophilization treatment, and hydrophobization treatment. Further, in the outer peripheral surface 2s of the catheter shaft 2 covered by the resin film 3, a region excluding the first end portion 5a and the second end portion 5b of the balloon 5 contains a known release agent such as a fluororesin. It is preferable that the release layer is formed on the surface. When the release layer is present, the region of the resin film 3 where the balloon 5 is formed is prevented from excessively adhering to the outer peripheral surface 2s, and the pressure fluid injected from the first through hole 7A and the second through hole 7B The region can be easily peeled off from the outer peripheral surface 2s, and the balloon 5 can be easily formed.

The thickness of the region of the resin film 3 where the balloon 5 is formed is, for example, preferably 0.001 mm to 0.40 mm, more preferably 0.01 mm to 0.30 mm, and further preferably 0.05 mm to 0.25 mm. preferable.
When the thickness is equal to or greater than the lower limit value, rupture of the balloon 5 can be further reduced. When the thickness is equal to or less than the upper limit value, the degree to which the balloon 5 is inflated can be increased while keeping the outer diameter of the distal end portion 2a of the balloon catheter 1 small.
Here, the thickness is a thickness when the balloon 5 is in a deflated state (an unexpanded state).

  The thickness of the stretchable (pressure-resistant) resin film covering the outer peripheral surface of the distal end portion of the balloon catheter of the present invention is the same as the thickness of the resin film in a cross section perpendicular to the longitudinal direction of the distal end portion. The arithmetic average of the values measured at any five locations for each cross section in any five cross sections (excluding the cross section including the through hole) in the region where the resin film is formed.

The constituent material of the resin film 3 may be a resin having elasticity, and is preferably a resin having excellent adhesion to the catheter shaft 2. For example, a resin material applied to a known balloon catheter such as silicone or latex is used. Can be mentioned. Among these, silicone having excellent biocompatibility is preferable, and rubbery silicone rubber exhibiting rubber elasticity at room temperature is more preferable.
The resin material of the resin film 3 and the resin material of the catheter shaft 2 may be the same or different.

  By injecting the pressure fluid into the resin film 3 from the opening 6b at the base end of the inflation lumen 6 through the through holes 7A and 7B, the first end 5a on the distal side of the balloon 5 in the resin film 3 and A region other than the region forming the second end portion 5 b on the proximal side swells away from the outer peripheral surface 2 s to form the balloon 5. At this time, the thickness of the expanded portion of the resin film 3 is usually thinner than that at the time of contraction. If the pressure fluid is excessively injected, the resin film 3 may be broken (the balloon 5 may be ruptured), or the first end portion 5a or the second end portion 5b may be peeled off from the outer peripheral surface 2s and the pressure fluid may leak and the balloon 5 There is a risk of wilting.

The volume of the pressure fluid injected to inflate the balloon 5, that is, the volume of the pressure fluid accommodated in the balloon 5, is, for example, 0.10 ml or more and 2.00 ml when the thickness of the resin film 3 is in the above range. The following is preferable, 0.15 ml or more and 1.50 ml or less is more preferable, 0.20 ml or more and 1.00 ml or less is further preferable, and 0.30 ml or more and 0.60 ml or less is particularly preferable.
When the volume is not less than the lower limit of the volume, the balloon 5 can be inflated to the extent that it functions.
When the volume is not more than the upper limit of the volume, the possibility that the balloon 5 is ruptured or deflated is reduced, and it becomes easy for the balloon 5 to maintain an inflated state with an appropriate pressure. Can be prevented from bending. Moreover, the volume of the balloon to be indwelled in the urinary bladder is suitable as a Foley catheter for humans or small animals when the volume is within the above range.

The balloon catheter 1 of this embodiment has the two through holes 7A and 7B. These through holes are adjacent to each other, and the distance between the through holes 7A and 7B is, for example, preferably 1.0 mm or more and 10.0 mm or less, more preferably 2.0 mm or more and 8.0 mm or less. More preferably, it is 0.0 mm or more and 6.0 mm or less.
Here, the separation distance is a distance at which the outer edge of the first through hole 7A and the outer edge of the second through hole 7B are closest to each other.
When the above separation distance is 1.0 mm or more, even if one through hole is blocked by the resin film 3 when the balloon 5 is contracted, the remaining pressure fluid can be easily discharged by the other through hole. Become.
When the separation distance is 10.0 mm or less, the length of the balloon 5 in the longitudinal direction (longitudinal direction of the catheter shaft 2) can be relatively shortened (for example, about 11.0 mm or more and 20.0 mm or less). As a Foley catheter for humans or small animals, the volume of the balloon placed in the bladder is suitable.

In the balloon catheter 1, the first end portion 5 a on the distal side of the balloon 5 is the most distal (tip side) root that fixes the balloon 5 when inflated to the outer peripheral surface 2 s of the catheter shaft 2. Similarly, the second end portion 5b on the proximal side of the balloon 5 is the most proximal (base end) root that fixes the balloon 5 to the outer peripheral surface 2s of the catheter shaft 2 during inflation.
The separation distance between the first end portion 5a and the second end portion 5b is also a long separation distance between the through holes 7A and 7B, for example, preferably 5.0 mm or more and 40.0 mm or less, and 8.0 mm or more and 30.0 mm or less. More preferably, it is 10.0 mm or more and 20.0 mm or less.
When the above-mentioned separation distance is in the above-mentioned preferable range, the volume of the balloon placed in the bladder is suitable as a Foley catheter for humans or small animals.

In the distal end portion 2 a of the balloon catheter 1, the catheter shaft 2 may extend further from the first end portion 5 a on the distal side of the balloon 5 to the distal end side.
In the use of the Foley catheter, it is preferable that a catheter shaft having a length of 10 mm or more and 50 mm or less is further provided from the first end portion 5a to the distal end side. Urine can be more easily excreted within the preferred range. Moreover, as a length of the catheter shaft 2 extended from the 2nd end part 5b to a base end side, 100 mm or more and 1000 mm or less are mentioned, for example. When the length is as described above, handling as a Foley catheter becomes easier.

The balloon catheter 1 described above has two through holes 7A and 7B, but the number of through holes may be two or more. The balloon 5 of the balloon catheter 1 may have the same central axis as the axis of the catheter shaft 2 or may be eccentric with respect to the axis of the catheter shaft 2. The shape of the balloon 5 may be any shape such as a substantially spherical shape or a substantially spheroid shape.
At the proximal end of the balloon catheter 1, an opening 4b of the lumen 4 and an opening 6b of the inflation lumen 6 are connected to a check valve and a connection port to an external device (for example, a syringe, a urine bag, etc.) as necessary. Any configuration used for a known catheter such as the above may be provided.

<< Production method of balloon catheter >>
The second aspect of the present invention is a method for manufacturing a balloon catheter having a resin film constituting a balloon that can be inflated and contracted on the outer peripheral surface of the catheter shaft, and has the following two steps.
First, the catheter shaft having one or more lumens that are liquid flow paths and one inflation lumen that is a fluid flow path for adjusting the pressure of the balloon is prepared.
The first step is a step of forming two or more through holes penetrating from the outer peripheral surface of the catheter shaft to the inflation lumen.
A 2nd process is a process of coat | covering the area | region in which the at least 2 or more through-hole was formed among the outer peripheral surfaces of the said catheter shaft with the said resin film.

  As an example of the manufacturing method of this aspect, a state of manufacturing the above-described balloon catheter 1 is schematically shown in FIG. The catheter shaft 2 having the lumen 4 and the inflation lumen 6 can be manufactured, for example, by extruding the first silicone rubber composition.

  The opening 6a on the distal end side of the inflation lumen 6 may be closed at this stage or may be closed at any later stage. Examples of the method for closing the opening 6a include a method of filling the opening 6a with an arbitrary resin composition, a method of dissolving the opening 6a by heating, and the like. A method of covering with heating by laser irradiation is simple and preferable. Further, in the extrusion molding, the catheter shaft 2 in which the opening 6a is previously closed may be formed.

  In the first step, as a method of forming the through holes 7A and 7B with respect to the inflation lumen 6 from the outer peripheral surface 2s of the catheter shaft 2 cut to an appropriate length, for example, according to the thickness of the through hole to be formed The method of puncturing the needle N from the outer peripheral surface 2s to the inflation lumen 6, the laser processing for irradiating the inflation lumen 6 from the outer peripheral surface 2s with the output laser light Z according to the thickness of the through hole to be formed, and the like. (FIG. 4A). The site | part which forms through-hole 7A, 7B sees in the longitudinal direction of the catheter shaft 2, and the location corresponding to the 1st edge part 5a of the distal side of the balloon 5 formed later, and the 2nd end of a proximal side Between the portions corresponding to the part 5b.

  Before performing the next second step, as an optional step, a fluororesin is formed in a region where the balloon 5 is formed on the outer peripheral surface 2s of the catheter shaft 2, that is, a region between the first end portion 5a and the second end portion 5b. A known release layer 8 made of a material such as is formed (FIG. 4B). Examples of the method for forming the release layer 8 in a desired region of the outer peripheral surface 2s include a method of applying a fluororesin composition to the region, a method of attaching a release film to the region, and the like. The step of forming the release layer 8 may be before or after the through holes 7A and 7B are formed.

In the second step, the distal end 2a of the catheter shaft 2 is dipped in the second silicone rubber composition and dried, or the second silicone rubber composition is applied to the distal end 2a of the catheter shaft 2 and dried. As a result, a resin film 3 made of silicone rubber is formed on the outer peripheral surface 2s (FIG. 4C). At this time, the resin film 3 is formed so as to extend to a region wider than the region where the release layer 8 is formed, that is, the region on the distal end side and the proximal end side including the first end portion 5a and the second end portion 5b. Thereby, the region including the first end portion 5a and the second end portion 5b where the resin film 3 is directly bonded to the outer peripheral surface 2s is difficult to peel off from the outer peripheral surface 2s when the balloon 5 is inflated (FIG. 1).
By the above method, the balloon catheter 1 according to the present invention can be manufactured.

When the second silicone rubber composition enters the through holes 7A and 7B when forming the resin film 3, a part of the resin film 3 is formed inside the through holes 7A and 7B. A part of this becomes a “navel” protruding into the inner space of the balloon 5 described above. The formation of the navel is allowed if the navel does not substantially affect the inflation and deflation of the balloon 5.
However, if the formation of the bulge is not acceptable, the second silicone rubber composition penetrates by sealing the distal end side opening 6a and the proximal end side opening 6b of the inflation lumen 6 in advance. It can suppress entering hole 7A, 7B.
As a method of sealing the openings 6a and 6b, for example, a method of filling the openings 6a and 6b with a resin composition that can be easily removed later, or a release sheet is attached to the openings 6a and 6b. The method of attaching is mentioned.

[Example]
The balloon catheter shown in FIG. 5 was manufactured by the manufacturing method of the second aspect of the present invention.
The total length from the distal end to the proximal end was about 20 cm, and a connection port and a check valve were provided at the opening portions of the lumen and the inflation lumen opened at the proximal end, respectively.
The same silicone rubber was used as a constituent material for the catheter shaft and the resin film. In the region corresponding to the balloon on the outer peripheral surface of the catheter shaft, a release layer made of a fluororesin was formed with a length of about 1 cm along the axial direction. A needle (φ0.7 mm) was punctured from the outer peripheral surface of the catheter shaft into the inflation lumen to form two through holes. The distance between the through holes was about 5 mm.
The outer diameter of the catheter shaft was 1.04 mm, the outer diameter of the balloon catheter including the resin film was 1.24 mm, and the thickness of the resin film was 0.20 mm. The outer diameter of the lumen was 0.484 mm, and the outer diameter of the inflation lumen was 0.246 mm. The separation distance between the lumen and the outer peripheral surface of the catheter shaft was 0.117 mm, and the separation distance between the inflation lumen and the outer peripheral surface of the catheter shaft was 0.078 mm.

  When a syringe was inserted into the check valve of the balloon catheter manufactured as described above and about 0.3 ml of distilled water was injected into the inflation lumen, the distilled water inflated the resin film through the two through holes, and the catheter shaft A spheroid balloon having a substantially concentric axis was formed (see FIG. 5). Next, distilled water in the balloon was sucked out with a syringe, and the balloon was deflated. At this time, the discharge of distilled water from the balloon and the contraction of the balloon proceeded smoothly and were able to return to the state before the inflation. This operation of expansion and contraction was repeated three more times, and it was confirmed that it could be operated smoothly every time.

[Comparative example]
A balloon catheter similar to the example was manufactured except that the number of through holes was changed to one.
When the balloon catheter of the comparative example was operated in the same manner as described above, the discharge of distilled water from the balloon was delayed during the second contraction, and the balloon could not be completely contracted.

  From the above test results, it is clear that the balloon catheter according to the present invention has an excellent operability that allows the balloon to be easily inflated and reliably deflated.

1 ... balloon catheter,
2 ... catheter shaft,
2a ... the tip,
2s ... outer peripheral surface,
3 ... resin film,
4 ... Lumen,
5 ... Balloon
5a ... the first end of the balloon,
5b ... the second end of the balloon,
6 ... Inflation lumen,
7A ... first through hole,
7B ... second through hole,
8: Release layer.

Claims (8)

A balloon catheter comprising a resin film constituting a balloon capable of expanding and contracting on the outer peripheral surface of a catheter shaft,
The catheter shaft is a lumen that is a liquid flow path;
An inflation lumen which is a fluid flow path for adjusting the pressure of the balloon,
A balloon catheter in which two or more through holes through which the fluid flows between the balloon and the inflation lumen are formed.   The balloon catheter according to claim 1, wherein an outer diameter of the catheter shaft is 2.0 mm or less.   The balloon catheter according to claim 1 or 2, wherein a thickness of the resin film when the balloon is contracted is 0.3 mm or less.   The balloon catheter as described in any one of Claims 1-3 whose volume of the fluid which the said balloon accommodates is 2 ml or less.   The balloon catheter according to any one of claims 1 to 4, wherein a distance between adjacent through holes among the two or more through holes is 1 mm or more and 10 mm or less.   The balloon catheter according to any one of claims 1 to 5, wherein the resin film is formed of silicone rubber.   The balloon catheter according to any one of claims 1 to 6, which is used for inserting a small animal into the urethra. A method for producing a balloon catheter comprising a resin film constituting a balloon capable of expanding and contracting on an outer peripheral surface of a catheter shaft,
Preparing the catheter shaft having a lumen that is a flow path of liquid and an inflation lumen that is a flow path of fluid that adjusts the pressure of the balloon;
Forming two or more through holes penetrating from the outer peripheral surface of the catheter shaft to the inflation lumen;
Covering the region where at least the two or more through holes are formed in the outer peripheral surface of the catheter shaft with the resin film.