JP2012239589A - Method for manufacturing in-vivo indwelling member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing an in-vivo indwelling member, in which sticking of an oxide is suppressed, with high manufacturing efficiency.SOLUTION: When manufacturing a secondary coil CL2 to be the in-vivo indwelling member by working a primary coil CL1 using a mandrel 11, the mandrel 11 around which the primary coil CL1 is to be wound has on its surface a spiral groove 12 for housing the primary coil CL1, and a groove pitch P in at least a part of the spiral groove 12 is ≥90% and ≤99% of the outer diameter D of the primary coil CL1.

Description

  The present invention relates to a method for manufacturing an in-vivo indwelling member.

  There are various tubular organs in the human body. Therefore, for example, when an external thoracotomy is complicated and difficult, a medical instrument such as a dilator or an obturator is guided from the outside toward the internal affected area through such a tubular organ. The treatment has been done.

  For example, when treating an aneurysm formed in a blood vessel, a catheter which is an example of a medical instrument is guided into the aneurysm through the blood vessel, and further, an indwelling member such as a metal coil is inserted into the aneurysm through the catheter. Inserted inside. According to such treatment, the aneurysm is filled with a metal coil or the like so that it becomes a thrombus and blood does not flow into the aneurysm. As a result, the aneurysm is prevented from rupturing.

  The metal coil for vascular occlusion is formed, for example, by forming a wire material such as platinum into a coil shape (primary coil) and further forming it into a coil shape (secondary coil) (note that Such a metal coil is also referred to as a double coil). Such a coil (i.e., secondary coil) is inserted into the catheter in a linearly stretched state and returns to the shape of the secondary coil when pushed out of the catheter placed in the tubular organ. Therefore, it can be said that this coil is suitable for occluding the inside of an aneurysm as described above or occluding a blood path in order to prevent a large amount of bleeding.

  In such a general technique for vascular occlusion, first, a vascular occlusion coil is selected according to the size of the aneurysm, and the coil is inserted into the aneurysm. The coil inserted in such an initial stage becomes a framework for inserting another coil into the aneurysm (the insertion of the coil into the aneurysm is also referred to as framing). Therefore, in framing, a coil having a shape that matches the initial aneurysm volume is selected, the coil length is relatively long, and the secondary coil diameter is relatively large, close to the aneurysm diameter. Is done.

  Next, in order to increase the coil occupancy ratio relative to the volume of the aneurysm, another coil is inserted into the frame formed by the aneurysm to fill the frame (the coil into the frame of such an aneurysm). Insertion is also referred to as filling). Therefore, in the filling, the coil must have a size that fits within the frame, and a coil that is shorter and smaller in diameter than the coil selected by framing is selected.

  Finally, in order to reduce the gap due to shape change over time after the procedure and the occurrence of compaction (compaction), in order to fill a small gap in the aneurysm and further increase the coil occupancy, the coil selected by filling However, a more flexible, shorter and smaller diameter coil is selected and placed (the insertion of such a coil is also referred to as finishing). That is, when a plurality of coils are inserted into an aneurysm and placed, the shape of the coil gradually decreases as the insertion order becomes slower.

  By the way, since the shape of the aneurysm formed in the blood vessel varies depending on the person, it is preferable that the coil has a shape along the shape of the aneurysm. That is, a complicated shape is required for the coil. In addition, a coil intended to increase the occupancy ratio in an aneurysm must be accommodated without dropping even a slight gap in the aneurysm. Therefore, such a coil (secondary coil) is designed to be flexible and have a rigid inclination, thereby enhancing the indwelling performance in the aneurysm.

  In Patent Document 1 showing a manufacturing method of such a secondary coil shape, for example, a vascular occlusion member made of platinum, palladium, rhodium, gold, tungsten, an alloy thereof, or stainless steel and a superelastic alloy is used. Wrapped around a spherical or deformed spherical form mandrel and heated at 1100 ° F.

  Patent Document 2 discloses a mandrel including a spherical main body having a groove and a coil seam protruding from the surface of the main body, and the fine cable forming the in-vivo indwelling member is aligned by the groove, It is wrapped around a mandrel and heated at 1100 ° F.

  That is, the conventional secondary coil shape manufacturing method uses a metal or ceramic material as a mandrel material, winds the primary coil along a simple or intentional groove shape, and performs a high temperature heat treatment of 1100 ° F. Yes.

JP 09-168541 A JP 2008-119488 A

  However, in the manufacturing methods of Patent Documents 1 and 2, the vascular occlusion member is remarkably oxidized due to the heating temperature, and a step for removing the oxide is required (that is, the oxide removing treatment step is included). This manufacturing method can be said to be a method with low manufacturing efficiency). Also, because of the spherical mandrel, even if the completed coil is inserted into the aneurysm, the gap in the aneurysm cannot be eliminated, and as a result, the patient is at risk of reopening after treatment. There is also.

  In addition, when the shape is imparted to the secondary coil by the manufacturing method of Patent Document 2, there is no concept of rigid inclination as the secondary coil because the primary coil is only wound along the simple groove.

  The present invention has been made to solve the above problems. And the objective is to provide the manufacturing method which can manufacture the in-vivo indwelling member which suppressed adhesion of an oxide with high manufacturing efficiency.

  In the in-vivo indwelling member manufacturing method, the primary coil is processed by a mandrel to manufacture a secondary coil to be an in-vivo indwelling member. And in this manufacturing method, the mandrel around which the primary coil is wound has a spiral groove for accommodating the primary coil on the surface, and the groove pitch in at least a part of the spiral groove is smaller than the outer diameter of the primary coil. And 90% or more and 99% or less.

  In addition, when processing a primary coil, it is preferable that the heating temperature to the primary coil is 550 degrees C or less.

  ADVANTAGE OF THE INVENTION According to this invention, the in-vivo indwelling member which suppressed adhesion of an oxide can be manufactured with high manufacturing efficiency.

FIG. 3 is a side view of a mandrel. FIG. 2 is a side view of a coil manufactured by the mandrel shown in FIG. 1. FIG. 3 is a side view of a mandrel. These are side views of a primary coil.

[Embodiment 1]
The following describes one embodiment with reference to the drawings. For convenience, hatching, member codes, and the like may be omitted, but in such a case, other drawings are referred to.

  In addition, the shape, material, size, length, or the like of each member of the in-vivo indwelling member (a kind of medical device) described as the embodiment is described as an example, and can be changed as appropriate.

  The in-vivo indwelling member (for example, a thrombus embolization member) is formed, for example, by processing a metal wire. Such processing may be performed a plurality of times, and the first processing is referred to as primary processing and the second processing is referred to as secondary processing.

  First, the wire will be described in detail. As the material of the wire, for example, platinum (platinum), tungsten, gold, tantalum, iridium, titanium, or stainless steel, or an alloy wire containing any material selected from these materials, or a superelastic alloy wire may be used. .

Then, such a wire is subjected to a primary processing step of winding around a core material of an appropriate size, so that the wound shape is retained, and becomes a coil CL1 as shown in FIG. 4 ( That is, the primary coil CL1 is completed)
The size of the primary coil CL1 is not particularly limited. For example, the outer diameter (φ) is preferably 0.200 mm or more and 0.500 mm or less. Further, after the primary coil CL1 is formed, an extension preventing wire formed of a metal wire or a polymer wire may be disposed in the lumen of the primary coil CL1.

  The primary coil CL1 becomes a secondary coil CL2 by further processing (secondary processing). In this secondary processing, a mandrel 11 is used as shown in FIG. The material of the mandrel 11 is not particularly limited, and examples thereof include ceramics typified by alumina, zirconia, silicon nitride, silicon carbide and the like, or heat resistant alloys. The material of the mandrel 11 may be alumina from the viewpoints of workability, wear resistance, and heat resistance.

  The mandrel 11 around which the primary coil CL1 is wound has a spiral groove 12 for accommodating the primary coil CL1 on the surface. A method of winding the primary coil CL1 around the spiral groove 12 will be described.

  First, a fine wire made of metal (for example, stainless steel) that is longer than the total length L of the primary coil CL1 and smaller than the inner diameter of the primary coil CL1 is passed through the lumen of the primary coil CL1. Then, the ultrafine wire (not shown) and the primary coil CL1 are wound around the mandrel 11 so as to be accommodated in the spiral groove 12 (that is, along the spiral groove 12). In this winding step, the mandrel 11 is fixed to a mandrel chuck (not shown), and the mandrel 11 is rotated while a uniform tension is applied to the fine wire, so that the fine wire and the primary coil CL1 are wound. Preferably.

  The primary coil CL1 wound around the mandrel 11 is heated to maintain its shape, and as a result, the secondary coil (emboli coil) CL2 is completed. In addition, the heat source required for this heating is not specifically limited, For example, the general heater which can adjust temperature is mentioned.

  In this heating, when heat is applied to the mandrel 11, it may be performed by heat transfer or by radiant heat. However, from the viewpoint of uniform heating or uniform heating, radiant heat is preferable.

  Here, the mandrel 11 will be described in detail. The mandrel 11 has a spiral groove 12 on the surface as shown in FIG. The groove pitch P of the spiral groove 12 is 90% or more and 99% or less (0.9D ≦ P ≦ 0.99D) with respect to the outer diameter D of the primary coil CL1.

  If such a mandrel 11 is compared with a case where the primary coil CL1 is spirally wound around the mandrel 11 and a case where the primary coil CL1 is wound around a mandrel having no groove on the surface, for example, The mandrel 11 having the groove 12 winds the primary coil CL1 more strongly. Therefore, stress is easily generated in the primary coil CL1 wound around the mandrel 11 having the spiral groove 12.

Therefore, in the secondary processing (processing for imparting a coil shape to the primary coil CL1), the mandrel 11 having the spiral groove 12 has a lower heating temperature than, for example, a mandrel having no groove on the surface. Can be suppressed.
For example, even when the heating temperature in the secondary processing is 550 ° C. or lower, the densely wound secondary coil CL2 is completed as shown in FIG.

  In general, the secondary coil CL2 is oxidized due to heating of the primary coil CL1 in the secondary processing, and the degree of oxidation corresponds to a relatively low heating temperature. Then, when the secondary coil CL2 is created by the mandrel 11 having the spiral groove 12, the secondary coil CL2 is not oxidized so much, so that the process of removing the oxide can be omitted (that is, the manufacturing process can be simplified). Figured).

  In addition, adverse effects that occur in the secondary coil CL2 produced at a high heating temperature exceeding 550 ° C., for example, a phenomenon in which metallic luster is lost due to significant oxidation and acicular oxides adhere to the spiral groove. It does not occur in the secondary coil CL2 processed by the mandrel 11 with 12 (acicular oxides can be confirmed by SEM or the like). As a result, the secondary coil CL2 cannot cause a problem that the oxide is peeled off and flows out into the blood vessel to cause a thrombus.

  In particular, in the case of the mandrel 11 including the spiral groove 12, the secondary coil CL2 can be completed even at a heating temperature of 500 ° C. or lower, and thus a safer secondary coil CL2 can be provided.

  That is, in the above in-vivo indwelling member method, the mandrel 11 including the spiral groove 12 that satisfies the conditional expression of 0.9D ≦ P ≦ 0.99D is used, so that the secondary coil provided with a rigid inclination is used. Since CL2 can be manufactured with high manufacturing efficiency, and the secondary coil CL2 suppresses the generation of oxides, the occurrence of resumption that can occur after the procedure can be prevented in advance.

[Embodiment 2]
A second embodiment will be described. In addition, the same code | symbol is attached about the member which has the same function as the member used in Embodiment 1, and the various description of the member is abbreviate | omitted.

  In the first embodiment, as shown in FIG. 1, the groove pitch P of the spiral groove 12 of the mandrel 11 is constant, but is not limited to this.

  For example, as shown in FIG. 3, the mandrel 11 may include different groove pitches (groove pitch P <groove pitch Q). That is, in the in-vivo indwelling member manufacturing method, at least part of the spiral groove 12 on the surface of the mandrel 11 has a groove pitch P that is 90% or more and 99% or less with respect to the outer diameter D of the primary coil CL1. It only has to have.

  Even in this case, since the secondary coil CL2 includes a portion processed with the groove pitch P, the secondary coil CL2 is manufactured by a mandrel including only a groove pitch (for example, a groove pitch Q) wider than the groove pitch P. Compared to the secondary coil, the heating temperature can be suppressed.

  As a result, even if it is the manufacturing method in Embodiment 2, the same effect as Embodiment 1 is produced.

  Further, the secondary coil CL2 processed by the mandrel 11 including different groove pitches includes a densely wound portion and a loosely wound portion, but such a secondary coil CL2 is densely wound over the entire length. In some cases, indwellability in the body (for example, aneurysm) may be improved as compared with the secondary coil or the loosely wound secondary coil. Therefore, for example, the secondary coil CL2 in which densely wound portions and loosely wound portions are alternately and randomly or periodically arranged may be used.

  In other words, if the sparse part (sparse pitch part) and the dense part (dense pitch part) are provided in the shape of the secondary coil CL2, the secondary coil CL2 is intentionally given a rigidity balance. become. As a result, it becomes easy to bend by having a sparse pitch portion, and a secondary coil CL2 that easily enters a space not filled with coils in an aneurysm is realized. That is, with the manufacturing method according to the second embodiment, it is possible to provide a blood vessel occlusion member (secondary coil CL2) with improved indwelling performance, and consequently, it is possible to suppress reopening of a patient treated with the blood vessel embolization member.

11 Mandrel 12 Spiral groove P Groove pitch Q Groove pitch D Primary coil outer diameter CL1 Primary coil CL2 Secondary coil [In-vivo indwelling member]

Claims (2)

In the in-vivo indwelling member manufacturing method of manufacturing a secondary coil to be an in-vivo indwelling member by processing the primary coil with a mandrel,
The mandrel around which the primary coil is wound has a spiral groove on the surface for accommodating the primary coil.
A method for producing an in-vivo indwelling member, wherein a groove pitch in at least a part of the spiral groove is 90% or more and 99% or less with respect to the outer diameter of the primary coil. The method for manufacturing an in-vivo indwelling member according to claim 1, wherein when the primary coil is processed, a heating temperature of the primary coil is 550 ° C. or less.