JP2007143568A - Catheter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catheter which can correspond to both of right and left coronary arteries by an operation which is not greatly different from that of a conventional catheter for a specified area. <P>SOLUTION: This catheter has a linear first section P1, curved line-form second sections P2 to P4, and a third section P5. In this case, the linear first section P1 constitutes a section from the proximal end of the catheter to the proximal end of the distal end section which constitutes a specified range from the distal end of the catheter. The curved line-form second sections P2 to P4 are connected with the first section, and form a section from the proximal end of the distal end section to a vicinity of the distal end of the catheter. The third section P5 is connected with the second sections, and forms a distal end proximal section including the distal end. The second sections curve in the same direction as the whole, and include a plurality of sections having different radii of curvature. The third section has a returning section P51 which is connected with the distal ends of the second sections, and curves in the opposite direction from the second sections, and a linear section P52 which forms a section from the distal end of the returning section to the distal end of the catheter. The catheter has a shape in which the distal end of the catheter is located in a vicinity of the first section. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a catheter used by being inserted into a blood vessel of a living body, and particularly to a catheter applicable to left and right coronary arteries.

  The catheter is inserted into the blood vessel percutaneously from the wrist, upper arm, thigh, etc., and a drug such as a contrast medium is administered into the blood vessel, the stenotic site of the blood vessel is expanded, or a foreign body is removed. It is widely used for the treatment.

  The blood vessels of a living body are connected to each other while having various thicknesses and shapes depending on the part. For this reason, conventionally, differently shaped catheters have been prepared according to the site where the distal end of the catheter is to be arranged, and are selected and used by the operator. As typical shapes of the catheter, there are, for example, a judkins type of coronary artery, an ampraz type, a pick tail type for a ventricle, and the like. Furthermore, in order to cope with individual differences in blood vessel shape and blood vessel connection position, catheters with the same shape and different sizes are prepared, and in reality, shapes corresponding to the types of blood vessels to be applied and for individual patients Based on the appropriate size, the catheter to be used is determined.

  These catheters are formed in a shape suitable for use at a specific site (blood vessel) so that the distal end of the catheter can be guided to a desired blood vessel site and stable placement can be performed. Thereby, application to the intended part can be easily performed, but application to other parts is not considered, and common use to a plurality of parts is difficult.

  Therefore, when performing diagnosis or treatment by applying a catheter to a plurality of sites, even if the site of application exists in the immediate vicinity, such as the right coronary artery and the left coronary artery, for each application site The catheter had to be changed. While the catheter has a length of about 1 m, the outer diameter is very thin, about 1 to 2 mm, and has a hollow structure for passing a guide wire, a drug, and the like. Therefore, the exchange is troublesome and the burden on the patient increases.

  A catheter (general shape catheter) having a shape considering use at a plurality of sites has been proposed for the purpose of reducing the burden of replacement and reducing the burden on the patient. For example, Patent Document 1 proposes a catheter for both left and right coronary arteries.

JP-A-7-308384

  However, the conventional general-purpose catheter as described in Patent Document 1 has a completely different shape from a catheter for a specific site that is normally used. Therefore, the guide wire operation for inserting the distal end into a desired blood vessel, for example, the left and right coronary arteries, is greatly different from a conventionally used catheter for a specific site and needs to be newly learned. . As a result, there is a problem that the burden on the operator increases and it takes time until it can be used.

  The present invention has been made in view of the problems of the prior art, and an object of the present invention is to provide a catheter that can handle both the left and right coronary arteries by an operation that is not significantly different from a conventional catheter for a specific site. .

  That is, the gist of the present invention is a catheter that is used by inserting a distal end into a coronary artery, and is configured from the proximal end portion of the catheter to the proximal end of the distal end portion constituting a predetermined range from the distal end of the catheter. A straight first part, a curved second part connected to the first part and forming from the proximal end of the tip part to near the tip of the catheter, and connected to the second part; A third portion forming a tip vicinity portion including the tip, and the second portion is curved in the same direction as a whole and includes a plurality of portions having different curvature radii, and the third portion is A return portion connected to the distal end of the second portion and curved in the opposite direction of the second portion, and a straight portion forming from the distal end of the return portion to the tip of the catheter; The tip of the catheter has a shape located in the vicinity of the first part. It resides in the catheter, wherein Rukoto.

  With such a configuration, according to the catheter of the present invention, it is possible to realize a catheter that can handle both the left and right coronary arteries by an operation that is not significantly different from a conventional catheter for a specific site.

Hereinafter, the present invention will be described in detail based on preferred embodiments with reference to the drawings.
FIG. 1 is a view showing an example of a left and right coronary artery catheter (Universal Diagnostic Catheter with Variable Curve) according to an embodiment of the present invention, and FIG. FIG. 1 (b) shows details of the shape near the tip of the catheter.

  The shape shown in FIG. 1 is a single shape when not in use, with no guide wire inserted. The left and right coronary artery catheter of this embodiment is composed of first to fifth portions P1 to P5. A first portion having a proximal end connected to a connector (not shown) provided with a guide wire, a drug insertion portion, etc., and extending from the distal end of the catheter to the proximal end of the distal end portion constituting a predetermined range P1 has a linear shape.

  The second to fourth portions P2 to P4 connected to the distal end of the first portion P1 have a shape curved in the same direction (direction approaching the first portion P1) as a whole. The second to fourth portions have different radii of curvature and form a substantially elliptical shape as a whole. The third portion P3 has the smallest radius of curvature, and the second portion P2 and the fourth portion P4 have a larger radius of curvature than the third portion. In this embodiment, the curvature radius of the 2nd part P2 and the 4th part P4 is made equal.

  The second portion P2, the third portion P3, and the fourth portion P4 do not need to have a constant curvature radius. The radius of curvature may change in each part. In this case, the radius of curvature of each part is represented by the smallest radius of curvature or the average radius of curvature. In the region where the radius of curvature changes in the second part P2 to the fourth part P4 (for example, the transition part between the second part and the third part or the transition part between the third part and the fourth part). The radius of curvature is continuously changed.

  One of the characteristics of the catheter of this embodiment is that the second to fourth portions P2 to P4 do not include a straight portion or a portion where the curvature radius changes rapidly. With such a shape, for example, a strong backup effect that does not yield to the reaction force when a contrast agent or the like is ejected can be obtained, and the catheter tip can be prevented from coming off the coronary artery opening. In particular, a thin catheter having an outer diameter of 3 to 4 Fr (1 to 4/3 mm) tends to have a small thickness and a low rigidity. Since the second to fourth parts P2 to P4 do not have a straight line part or a part where the radius of curvature changes suddenly, there is no place where the reaction force concentrates, and the reaction force in the whole second to fourth parts P2 to P4. Therefore, the catheter of the present embodiment has a shape that is particularly effective for a thin catheter.

  The fifth portion P5 that forms the vicinity of the tip including the tip of the catheter is connected to the distal end of the fourth portion P4, and is a portion curved in the direction opposite to the second to fourth portions P2 to P4 ( (Return portion) P51 and a linear portion P52 that forms from the distal end of the portion P51 to the tip of the catheter. One of the features of the catheter of the present embodiment is that it has the return portion P51 and that the portion P52 forming the distal end of the catheter has a linear shape. Further, the distal end of the catheter is located in the vicinity of the first portion P1.

As a specific example, in a catheter having a total length of 1000 mm, an outer diameter of 1 mm, and an inner diameter of 0.8 mm, preferred ranges of dimensions in the figure are as follows.
d1 = 13-28 mm, d2 = 19-40 mm, d3 = 21-46 mm, d4 = 5.4-12 mm, d5 = 4.3-10 mm, d6 = 0-10 mm,
The length of the straight portion P52 = 1.6 to 4.0 mm, the length of the return portion P51 = 1.4 to 10.4 mm, and the total length of P2 to P5 is 55 to 130 mm.
The curvature radius R2 of the second portion P2 = 14 to 32 mm, the curvature radius R3 of the third portion P3 = 7.7 to 18 mm, the curvature radius R4 of the fourth portion P4 = 14 to 32 mm, the fifth portion P5 ( The radius of curvature R51 of the inner side is 3.7 to 8 mm, and the radius of curvature R52 of the fifth portion P5 (outer side) is 5 to 11 mm.
Among these, the specific value of d2 is determined so as to be within the diameter of the ascending aorta of the patient (although it varies depending on individual differences, it is about 19 to 40 mm). Other values can be appropriately determined according to the magnitude of the value of d2.

  The catheter of this embodiment can be formed from a resin such as a polyethylene resin, a polyamide resin, or a polyester resin. If it is necessary to adjust the rigidity, a resin can be mixed and used. There is also a form in which fine wires are knitted into an intermediate layer of a multilayer structure. In addition, the catheter of this embodiment has the characteristics in a shape, The material and manufacturing method used conventionally can be used about a material and a manufacturing method.

  The catheter of this embodiment is used by being inserted into an artery from the limbs, for example. First, the guide wire is inserted into the catheter through the connector at the end, and the inside of the catheter is passed through the guide wire. Then, while confirming the position of the tip of the marker by X-ray imaging, the tip of the guide wire is first pushed inside the blood vessel and moved to a position near the desired position.

  Next, with the guide wire fixed, the catheter is inserted into the blood vessel along the guide wire. Although the guide wire and the catheter may be inserted into the blood vessel at the same time, it is preferable that the tip of the catheter does not precede the tip of the guide wire.

  FIG. 6 is a diagram showing the relationship between the distal end position of the guide wire and the outer shape of the catheter of the present embodiment. In the drawing, the tip position of the guide wire is indicated by an arrow. As the distal end of the guide wire is pushed in, the second to fifth portions of the catheter are deformed as shown in FIGS. The catheter tip can be inserted into a desired coronary ostium while utilizing this deformation. Specific operations will be described below.

  FIG. 2 is a diagram for explaining the shape change when the catheter of this embodiment is applied as a left coronary artery catheter. 2 to 4 show an example in which the catheter of the present embodiment is inserted from the femoral artery. When inserted into the ascending aorta via the brachial artery, the contact site between the catheter and the inner wall of the aorta is slightly different (further, it differs depending on whether the right upper arm or the left upper arm). In this case, the catheter enters from the upper blood vessel.

  FIG. 2A shows the shape of the distal end portion in a state where the guide wire is not inserted and is not inserted into the blood vessel, and corresponds to the state of FIG. FIG. 2B shows a shape in which the guide wire is inserted in this state and the guide wire is penetrated (not inserted into the body).

  FIG. 2 (c) shows the shape in the state of approaching the left coronary artery. During the approach, the shape of the catheter parts P2 to P5 and the position of the tip are adjusted while moving the guide wire back and forth. Then, as shown in FIG. 2 (c), when the distal end of the catheter is located in the vicinity of the left coronary artery mouth and the upper part of the Valsalva sinus, the guide wire is removed.

  When the guide wire is pulled out, the catheter portions P2 to P5, which have been deformed by the rigidity of the guide wire, attempt to restore the original shape shown in FIG. 1 or FIG. Specifically, the substantially elliptical shape formed by the portions P2 to P5 tries to return from the expanded state to the closed state. As a result, a portion near the distal end of the catheter, in particular, a portion (returned portion) P51 that is bent opposite to the portions P2 to P4 is pressed against the left coronary artery opening and is stabilized (FIG. 2 (d)).

  When the contrast agent is ejected, a force opposite to the ejection direction is applied to the catheter tip as a reaction of the ejection force. However, the catheter of the present embodiment is in contact with the inner wall of the ascending aorta near the proximal portion (or the distal portion of P1) from the portion P2.

  Further, as described above, the portions P2 to P4 that form most of the distal end portion of the catheter do not have a linear configuration, and have a shape that repels forces that try to expand the portions P2 to P4. And in these parts P2-P4, the restoring force (force in the direction where the front-end | tip P52 approaches the part P1) which tries to return to the shape shown to Fig.2 (a) is acting. As a result, when the contrast agent or the like is introduced in the state shown in FIG. 2D, the force in the direction of separating the tip from the portion P1 applied to the tip of the catheter can be countered by the entire portions P2 to P4. Further, the position stability is further increased by contacting the inner wall of the ascending aorta near the proximal portion (or the distal portion of P1) from the portion P2.

  If the portions P2 to P4 include a linear portion, the portion does not have a restoring force (backup force), and therefore does not have a function to counteract the stress due to the reaction. In addition, since stress concentrates at both ends of the linear portion, the risk of breakage or the like increases with respect to a configuration having a shape including a portion that is curved in the same direction and has a different curvature radius as in this embodiment. Is also not preferred. In terms of stress concentration, there is a similar problem even when there is a portion where the radius of curvature changes greatly.

  Further, since the portion P52 constituting the distal end has a linear shape, the drug reliably reaches the back of the coronary artery in parallel with the axial direction (drug injection direction) of the coronary artery.

FIGS. 3A to 3D are diagrams showing examples of shapes of left coronary artery catheters that are conventionally used in a standard manner in a state corresponding to FIGS. 2A to 2D.
As shown in FIG. 3A, the conventional catheter for the left coronary artery has a linear configuration 30 at the distal end portion. As shown in FIG.3 (b), the shape in the state which inserted the guide wire is similar to the catheter of this embodiment except the shape of the part P5. However, in the approach, the straight portion 30 maintains a straight shape regardless of the tip position of the guide wire (FIG. 3C).

  Even if the guide wire is removed and the distal end of the catheter can enter the left coronary artery, for example, when stress due to the reaction of the drug injection acts, the front end 31 of the straight portion 30 is shown as a dotted line. The tip moves away from the left coronary artery. This is because the straight portion 30 does not have a restoring force as the catheter portions P2 to P4 of the present embodiment have, and the shape of the straight portion 30 does not have a shape that can resist the stress caused by the reaction. by.

  Further, in the conventional catheter for the left coronary artery, various types of catheters having different lengths of the straight portions 30 and sizes (corresponding to d2) shown in 32 of FIG. It was necessary to prepare. However, in the catheter of the present embodiment, the length of the portion corresponding to the straight portion 30 of the conventional configuration can be arbitrarily adjusted by operating the guide wire to deform the portions P2 to P4. That is, if the tip of the guide wire is inserted to the vicinity of the tip of the catheter, the guide tip is expanded by the rigidity of the guide wire, and the linear shape portion becomes long. On the other hand, if the tip is retracted, the linear shape portion is shortened by the restoring force. Therefore, the catheter of this embodiment can respond to various patients with one type of shape.

  In addition, since the shape of the catheter of the present embodiment is similar to that of a conventional left coronary artery catheter by adjusting the insertion degree of the guide wire, the operation of the catheter is also a conventional left coronary catheter. There is no big difference. Therefore, an operator who is familiar with the conventional catheter for the left coronary artery can be used in a short time.

  FIG. 4 is a diagram for explaining a change in shape when the catheter of the present embodiment is applied as a right coronary artery catheter. Since the catheter of this embodiment can be applied to both the left and right coronary arteries, FIGS. 4 (a) and 4 (b) are the same as FIGS. 2 (a) and 2 (b).

  FIG. 4C showing the shape during the approach also has a shape substantially similar to that in FIG. However, because the entrance of the right coronary artery is located closer to the Valsalva sinus than the left coronary artery (deeper), the guide wire is pushed deeper than when applied to the left coronary artery, and the portions P2 to P4 extend. Transform into an (open) state. Further, in order to facilitate the inversion of the catheter, the portions P2 to P4 are deformed into an extended (open) state.

  Then, by rotating the catheter to reverse the direction of the catheter tip by 180 degrees, the tip enters the right coronary artery. Then, the guide wire is pulled out (FIG. 4D). Even when applied to the right coronary artery, the force to return to the shape of FIG. 4 (a) after pulling out the guide wire (substantially upward force in the figure) acts on the parts P2 to P4. A portion (returned portion) P51 bent in the opposite direction to the portions P2 to P4 is caught in the coronary artery opening and is stabilized.

FIGS. 5A to 5D are diagrams showing examples of the shape of the right coronary artery catheter that is conventionally used as a standard in a state corresponding to FIGS. 4A to 4D.
As shown in FIG. 5A, the conventional left coronary artery catheter has a linear configuration 50 having a large curvature radius at the distal end portion. As shown in FIG.3 (b), the shape in the state which inserted the guide wire is similar to the catheter of this embodiment except the shape of the part P5. However, in the approach, the straight portion 50 maintains the straight shape regardless of the tip position of the guide wire (FIG. 5C). Similarly to the catheter of the present embodiment, the conventional catheter for the right coronary artery is rotated from the state of FIG. 5 (c), the tip is inverted by 180 degrees, and then the guide wire is pulled out. (Figure 5 (d)).

  Even if the guide wire is removed and the distal end of the catheter enters the right coronary artery, for example, when stress due to the reaction of the drug injection acts, the front end 51 of the straight line portion 50 is shown as a dotted line. And the tip is disengaged from the right coronary artery. This is because the straight portion 50 does not have a restoring force as the catheter portions P2 to P4 of the present embodiment have, and the shape of the straight portion 50 is not a shape that can resist the stress caused by the reaction. by.

  Further, in the conventional catheter for the right coronary artery, it is necessary to prepare various types of catheters having different lengths of the straight portions 50 in order to meet individual differences among patients. However, in the catheter of this embodiment, the length of the part corresponding to the linear part 50 of the conventional configuration can be arbitrarily adjusted by operating the guide wire to deform the parts P2 to P4. That is, if the tip of the guide wire is inserted to the vicinity of the tip of the catheter, the guide tip is extended to the catheter tip due to the rigidity of the guide wire, and the linear shape portion becomes long. On the other hand, if the tip is retracted, the linear shape portion is shortened by the restoring force. Therefore, the catheter of this embodiment can respond to various patients with one type of shape.

  In addition, since the shape of the catheter of this embodiment is similar to that of a conventional right coronary catheter by adjusting the insertion degree of the guide wire, the operation of the catheter is also different from that of the conventional right coronary catheter. There is no big difference. Therefore, an operator who is familiar with the conventional right coronary catheter can be used in a short time.

  As described above, according to the catheter of the present embodiment, it can be used in common for both the left and right coronary arteries, and the shape during the approach is similar to that of the conventional catheter. It can be used without need.

  In addition, the straight portion continuing from the end of the catheter and the portion connecting the vicinity of the distal end of the catheter have a curved shape that is curved in the same direction as a whole, and includes a plurality of portions having different curvature radii. Can be continuously deformed by operating the guide wire. Therefore, the position of the tip can be adjusted flexibly, and even when a catheter of a different size is conventionally required to be replaced, it can be handled without replacement. Further, when a drug is ejected from the catheter tip, even if stress due to reaction is applied, the tip can be maintained in a stable state without coming out of the coronary artery opening.

  In addition, since the tip is formed linearly, the tip of the catheter is maintained in a state parallel to the central axis in the length direction of the coronary artery, and a drug or the like ejected from the tip is easily introduced into the back of the coronary artery. .

It is a figure which shows the example of the catheter for left and right coronary arteries which concerns on embodiment of this invention. It is a figure explaining the shape change at the time of applying the catheter of this embodiment as a catheter for left coronary arteries. It is a figure which shows the example of a shape in the state corresponding to FIG. 2 (a)-(d) about the catheter for left coronary arteries conventionally used as standard. It is a figure explaining the shape change at the time of applying the catheter of this embodiment as a catheter for right coronary arteries. It is a figure which shows the example of a shape in the state corresponding to Fig.4 (a)-(d) about the catheter for right coronary arteries conventionally used normally. It is a figure which shows the relationship between the front-end | tip position of a guide wire, and the external shape of the catheter of this embodiment.

Claims (4)

A catheter used by inserting a tip into a coronary artery,
A linear first portion that forms from the proximal end of the catheter to the proximal end of the tip portion that defines a predetermined range from the tip of the catheter;
A curved second portion connected to the first portion and forming from the proximal end of the tip portion to near the tip of the catheter;
A third portion connected to the second portion and forming a portion near the tip including the tip;
The second portion is curved in the same direction as a whole and includes a plurality of portions having different curvature radii,
The third portion is connected to the distal end of the second portion, and forms a return portion that curves in a direction opposite to the second portion, and the distal end of the return portion to the tip of the catheter. A straight portion to be
A catheter having a shape in which a distal end of the catheter is positioned in the vicinity of the first portion.   The second portion is connected to the distal end of the first portion, has a proximal portion having a first radius of curvature, is located distal to the proximal portion, and the second portion The intermediate portion having the smallest second radius of curvature, and a distal portion located on the tip side of the intermediate portion and having a third radius of curvature smaller than the intermediate portion. The catheter according to 1.   The catheter of claim 2, wherein the third radius of curvature is equal to the first radius of curvature.   The catheter according to claim 2 or 3, wherein the proximal portion and the intermediate portion, and the intermediate portion and the distal portion are connected by a transition portion having a gradually changing radius of curvature.

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