Patent Publication Number: US-2023145301-A1

Title: Medical instrument set, delivery system, and embolic device delivery medical system

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application is a continuation of International Application No. PCT/JP2021/026419 filed on Jul. 14, 2021, which claims priority to Japanese Application No. 2020-122112 filed on Jul. 16, 2020, the entire content of both of which is incorporated herein by reference. 
    
    
     TECHNOLOGICAL FIELD 
     The present disclosure generally relates to a medical instrument set, a delivery system, and an embolic device delivery medical system. 
     BACKGROUND DISCUSSION 
     There is currently no drug treatments that can prevent an aneurysm (aortic aneurysm) generated in an aorta of a patient from increasing in diameter and rupturing. Surgical treatment (surgery) is generally performed for an aneurysm having a diameter that has a risk of rupturing. Further, in a surgery of the aortic aneurysm of the related art, artificial blood vessel replacement surgery in which an artificial blood vessel is transplanted by laparotomy or thoracotomy has been used, and in recent years, application of lower invasive stent graft interpolation (endovascular aneurysm repair: EVAR) has been rapidly expanding. 
     For example, in stent graft interpolation for an abdominal aortic aneurysm (AAA), a catheter having a stent graft at a distal end of the stent graft is inserted from a peripheral blood vessel of the patient, and the stent graft is expanded and indwells in an aneurysm lesion, thereby blocking a blood flow to the aneurysm and preventing the aneurysm from rupturing. 
     In general, a stent graft used in the stent graft interpolation has a structure in which two types of members, that is, a “main body portion” including bifurcated portions bifurcated into a substantially Y-shape and “leg portions” attached to the bifurcated portions and attached to a right iliac artery and a left iliac artery, respectively, are assembled. 
     Therefore, in the stent graft interpolation, so-called “endoleak” in which the blood flow remains in the aneurysm may occur due to blood leakage from a periphery of the stent graft due to insufficient adhesion of the interpolated stent graft, backflow of blood from a thin blood vessel (side branch blood vessel) branched from the aneurysm, or the like. In this case, since pressure is applied to a wall of the aneurysm by the blood flow entering the aneurysm, there is a potential risk of rupture of the aneurysm. 
     U.S. Pat. No. 9,561,096 discloses a device including a catheter capable of holding a compressed relatively elongated sponge (embolic device) in a lumen of the device and a plunger for pushing out the embolic device held in the catheter into an aneurysm filled with blood in order to block blood flow remaining in an aortic aneurysm due to endoleak. Since the sponge used in this device expands immediately when exposed to the blood, the sponge is pushed out into the aneurysm and expands when absorbing the blood in the aneurysm, and the sponge indwells in the aneurysm in this state to block the blood flow and prevent rupture. 
     In endoleak embolization including the technique disclosed in U.S. Pat. No. 9,561,096, the following “direct insertion method” and “indirect insertion method” are conceivable as embolic device delivery methods for delivering an embolic device into an aneurysm through a catheter. 
     The “direct insertion method” is a delivery method including: a procedure for inserting a first catheter in which an embolic device is loaded into a sheath of a second catheter indwelling in a body lumen (procedure A 1 ); a procedure for inserting a delivery pusher into the first catheter while a distal end of the first catheter reaches the aneurysm to deliver the embolic device into the aneurysm (procedure A 2 ); and a procedure for removing the first catheter and the delivery pusher from the second catheter after the embolic device indwells in the aneurysm (procedure A 3 ). In the direct insertion method, the embolic device is pushed out into the aneurysm and indwells in the aneurysm by inserting and pushing out the delivery pusher into the first catheter. 
     The “indirect insertion method” is a delivery method including: a procedure for inserting part of the distal end of the first catheter loaded with the embolic device into the sheath of the second catheter indwelling in the body lumen (procedure B 1 ); a procedure for inserting a loading pusher into the first catheter to transfer the embolic device to the second catheter (procedure B 2 ); a procedure for removing the loading pusher and the first catheter from the second catheter (procedure B 3 ); a procedure for inserting the delivery pusher into the second catheter to deliver the embolic device into the aneurysm (procedure B 4 ); and a procedure for removing the delivery pusher from the second catheter after the embolic device indwells in the aneurysm (procedure B 5 ). In the indirect insertion method, the embolic device is moved from the first catheter to the second catheter by the loading pusher, and is pushed out into the aneurysm and indwelling in the aneurysm by inserting and pushing out the delivery pusher into the second catheter. 
     However, these two delivery methods have the following problems (problems  1  to  3 ), particularly in terms of the complexity of the procedures and procedure time. 
     (Problem  1 ) In the direct insertion method, the first catheter requires flexibility and kink resistance such that the first catheter can be inserted following a shape of the meandering blood vessel. In order to fulfill these functions, it is necessary to make a flexible catheter body, and there is a risk that the loaded embolic device may be damaged during packaging or unpacking. When the embolic device indwells in the aneurysm, both the first catheter and the delivery pusher should be inserted into the aneurysm along a meandering flow path of the blood vessel, which can increase the difficulty of the procedures. 
     (Problem  2 ) In the indirect insertion method, since the number of procedures is larger than that in the direct insertion method, and procedures such as insertion and removal of a device are complicated, the procedure time may be longer. 
     (Problem  3 ) Both the direct insertion method and the indirect insertion method are methods for pushing out the embolic device into the aneurysm in a state where at least a part of the first catheter to which the embolic device is loaded is inserted into the second catheter. Accordingly, an outer diameter of the first catheter is smaller than an inner diameter of the second catheter, and an outer diameter of the embolic device is smaller than an inner diameter of the first catheter. Therefore, in order to make a required amount of small-diameter embolic device indwell in the aneurysm, the number of inserted embolic device inevitably increases, and the procedure time may be relatively long. 
     SUMMARY 
     A medical instrument set, a delivery system, and an embolic device delivery medical system are disclosed, which are capable of shortening procedure time by simplifying the procedure and reducing the number of steps of the procedure. 
     A medical instrument set according to an embodiment is a medical instrument set for delivering an embolic device into an aneurysm via a delivery catheter. The delivery catheter includes a sheath that includes a sheath lumen and a distal end opening that communicates with the sheath lumen, and a sheath hub that includes a communication passage communicating with a proximal end of the sheath lumen and is provided on a proximal side of the sheath. The medical instrument set includes: an embolic device loading catheter that includes a catheter body including a loading lumen loaded with the embolic device and having an open distal end, and a proximal hub including an insertion passage communicating with a proximal end of the loading lumen; and a delivery pusher that includes an elongated pusher body insertable into the loading lumen through the insertion passage of the proximal hub of the embolic device loading catheter. The catheter body includes a distal connection portion attachable to and detachable from the sheath hub of the delivery catheter on a distal side of the catheter body. The pusher body has a body length longer than a distance from a proximal end of the insertion passage of the proximal hub to the distal end opening of the sheath of the delivery catheter in a connected state where the distal connection portion of the catheter body is connected to the sheath hub of the delivery catheter, and when the pusher body is inserted from the insertion passage of the proximal hub in the connected state, the embolic device is passed through the sheath lumen of the delivery catheter and pushed out from the distal end opening of the delivery catheter into the aneurysm. 
     A delivery system according to an embodiment includes the medical instrument set and the delivery catheter, and is configured such that, in the connected state, the embolic device is passed through the sheath lumen of the delivery catheter by the delivery pusher inserted from the insertion passage of the proximal hub and is pushed out from the distal end opening of the delivery catheter into the aneurysm. 
     An embolic device delivery medical system according to an embodiment includes: the delivery system; and an elongated insertion assisting member to be assembled into the sheath lumen of the delivery catheter in order to assist delivery of the delivery catheter into an aneurysm. The insertion assisting member includes a guide wire lumen that penetrates from a distal end to a proximal end and has a diameter smaller than that of the sheath lumen of the delivery catheter. 
     An embolic device delivery medical system according to an embodiment includes: a delivery catheter, the delivery catheter including a sheath that includes a sheath lumen and a distal end opening that communicates with the sheath lumen, and a sheath hub that includes a communication passage communicating with a proximal end of the sheath lumen and is provided on a proximal side of the sheath; an embolic device loading catheter that includes a catheter body including a loading lumen configured to be loaded with the embolic device and having an open distal end, and a proximal hub including an insertion passage communicating with a proximal end of the loading lumen; a delivery pusher that includes an elongated pusher body insertable into the loading lumen through the insertion passage of the proximal hub of the embolic device loading catheter; the embolic device loading catheter including a distal connection portion configured to be attachable to and detachable from a sheath hub of a delivery catheter at a distal portion of the catheter body; the pusher body having a body length longer than a distance from a proximal end of the insertion passage of the proximal hub to the distal end opening of the sheath of the delivery catheter in a connected state where the distal connection portion of the catheter body is connected to the sheath hub of the delivery catheter, and when the pusher body is inserted from the insertion passage of the proximal hub in the connected state, the embolic device is configured to pass through the sheath lumen of the delivery catheter and to be pushed out from the distal end opening of the delivery catheter into the aneurysm; and an elongated insertion assisting member configured to be assembled into the sheath lumen of the delivery catheter in order to assist delivery of the delivery catheter into the aneurysm, and wherein the insertion assisting member includes a guide wire lumen that penetrates from a distal end to a proximal end and has a diameter smaller than that of the sheath lumen of the delivery catheter. 
     A method according to an embodiment includes: introducing a distal portion of a delivery catheter into a living body and positioning the distal end of the delivery catheter in an aneurysm in the living body, the delivery catheter including a sheath that includes a sheath lumen and a distal end opening that communicates with the sheath lumen, and a sheath hub that includes a communication passage communicating with a proximal end of the sheath lumen and is provided on a proximal side of the sheath; connecting a distal portion of an embolic device loading catheter to the proximal end of the delivery catheter, the embolic device loading catheter including a catheter body including a loading lumen loaded with an embolic device and having an open distal end, and a proximal hub including an insertion passage communicating with a proximal end of the loading lumen; introducing a distal end of a delivery pusher into the embolic device loading catheter by way of the proximal end of the loading lumen, the delivery pusher including an elongated pusher body insertable into the loading lumen through the insertion passage of the proximal hub of the embolic device loading catheter, and wherein the pusher body has a body length longer than a distance from a proximal end of the insertion passage of the proximal hub of the embolic device loading catheter to the distal end opening of the sheath of the delivery catheter when the distal portion of the catheter body is connected to the proximal end of the delivery catheter; and moving the delivery pusher in a forward direction to push the embolic device out of the embolic loading catheter into the sheath lumen of the delivery catheter and out of the sheath lumen of the delivery catheter into the aneurysm. 
     According to at least one embodiment of the disclosure, it is possible to shorten the procedure time by simplifying the procedure and reducing the number of steps associated with the procedure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a diagram showing configurations of a medical instrument set and a delivery set according to the present embodiment. 
         FIG.  2    is a diagram showing a configuration of an embolic device delivery medical system according to the present embodiment. 
         FIG.  3 A  is a schematic cross-sectional view showing one configuration example of an engagement portion of the medical instrument set. 
         FIG.  3 B  is a schematic cross-sectional view showing an engaged state of the engagement portion in  FIG.  3 A . 
         FIG.  4 A  is a schematic cross-sectional view showing another configuration example of the engagement portion of the medical instrument set. 
         FIG.  4 B  is a schematic cross-sectional view showing an engaged state of the engagement portion in  FIG.  4 A . 
         FIG.  5    is a schematic cross-sectional view showing a connected state between an embolic device loading catheter and a delivery catheter. 
         FIG.  6 A  is a partially enlarged view of a vicinity of a handle portion of a delivery pusher. 
         FIG.  6 B  is a partially enlarged view showing an inserted state of the delivery pusher. 
         FIG.  7 A  is an operation example of the embolic device delivery medical system according to the present embodiment, showing a state where the delivery catheter is delivered into an aneurysm. 
         FIG.  7 B  is an operation example of the embolic device delivery medical system according to the present embodiment, showing a state where a stent graft is deployed in the aneurysm. 
         FIG.  7 C  is an operation example of the embolic device delivery medical system according to the present embodiment, showing a state before the embolic device loading catheter is connected to the delivery catheter. 
         FIG.  7 D  is an operation example of the embolic device delivery medical system according to the present embodiment, showing a state where the embolic device loading catheter is connected to the delivery catheter. 
         FIG.  7 E  is an operation example of the embolic device delivery medical system according to the present embodiment, showing a state where the delivery pusher is being inserted into the embolic device loading catheter. 
         FIG.  7 F  is an operation example of the embolic device delivery medical system according to the present embodiment, showing a state where the embolic device is pushed out into the aneurysm by the delivery pusher. 
         FIG.  7 G  is an operation example of the embolic device delivery medical system according to the present embodiment, showing a state where the embolic device loading catheter is detached from the delivery catheter. 
         FIG.  8 A  is a modification of the embolic device loading catheter according to the present embodiment, showing a state before the engagement portion is engaged. 
         FIG.  8 B  is a modification of the embolic device loading catheter according to the present embodiment, showing a state after the engagement portion is engaged. 
     
    
    
     DETAILED DESCRIPTION 
     Set forth below with reference to the accompanying drawings is a detailed description of embodiments of a medical instrument set, a delivery system, and an embolic device delivery medical system. Note that since embodiments described below are preferred specific examples of the present disclosure, although various technically preferable limitations are given, the scope of the present disclosure is not limited to the embodiments unless otherwise specified in the following descriptions. In the drawings, the same or corresponding parts are denoted by the same reference numerals. In the description of the present embodiment, the description of the same or corresponding parts will be omitted or simplified as appropriate. 
     Further, in the accompanying drawings, for convenience of illustration and understanding, a scale, an aspect ratio, a shape, and the like may be changed from actual ones and may be schematically expressed as appropriate, and the drawings are just examples and do not limit the interpretation of the disclosure. 
     In the present specification, in an operation direction of each part constituting an embolic device delivery medical system  300 , for example, a side on which an embolic device  10  is to be conveyed into an aneurysm in a direction along an axial direction of a delivery catheter  40  is referred to as a “distal side (or a distal portion)”, and a side that is located on a side opposite to the distal side in the axial direction and on which a surgeon performs an operation, for example, with his/her hands (a side from which the delivery catheter  40  is removed) is referred to as a “proximal side (or a proximal portion)”. In the present specification, a “distal end” means a certain range in the axial direction including a most distal end, and a “proximal end” means a certain range in the axial direction including a most proximal end. 
     A medical instrument set  100 , a delivery system  200 , and the embolic device delivery medical system  300  according to the present embodiment may be applied to endoleak embolization for stent graft interpolation of an abdominal aortic aneurysm (AAA), which is an example of a treatment method for preventing rupture of an aneurysm generated in a blood vessel. In addition, the treatment method in which the medical instrument set  100 , the delivery system  200 , and the embolic device delivery medical system  300  according to the present embodiment are used is not limited to the endoleak embolization, and can also be applicable to other intervention treatment methods for preventing the rupture of the aneurysm generated in the blood vessel. 
     Configuration 
     Next, configurations of the medical instrument set  100 , the delivery system  200 , and the embolic device delivery medical system  300  according to the present embodiment will be described.  FIG.  1    shows each device constituting the medical instrument set  100  and the delivery system  200  according to the present embodiment, and  FIG.  2    shows each device constituting the embolic device delivery medical system  300  according to the present embodiment. 
     First, the embolic device  10  used in the medical instrument set  100 , the delivery system  200 , and the embolic device delivery medical system  300  according to the present embodiment will be described. 
     Embolic Device 
     The embolic device  10  indwells in an aneurysm such as an aortic aneurysm generated in the blood vessel and expands by absorbing a liquid containing blood flowing into the aneurysm. The embolic device  10  is loaded into an embolic device loading catheter  20 , and with the embolic device loading catheter  20  connected to the delivery catheter  40 , the embolic device  10  is pushed out by a delivery pusher  30  and indwells in the aneurysm. 
     The embolic device  10  can be an elongated fibrous linear body made of an expandable material (polymer material (water-absorbing gel material) or the like) that expands by contacting with an aqueous liquid containing the blood under a physiological condition. That is, in this embodiment, the embolic device  10  is a swellable embolic material. The embolic device  10  is an elongated umbilical member having a substantially circular cross-sectional shape in a direction orthogonal to a longitudinal direction, and is relatively fragile before expansion in which the embolic device  10  indwells in the aneurysm. The cross-sectional shape of the embolic device  10  is not particularly limited, and may be a polygonal shape in addition to the substantially circular shape. 
     Here, the “physiological condition” means a condition having at least one environmental characteristic in a body or on a body surface of a mammal (for example, humans). Such a characteristic includes an isotonic environment, a pH buffering environment, an aqueous environment, a pH near neutral (about 7), or a combination of the isotonic environment, the pH buffering environment, the aqueous environment, and the pH near neutral. The “aqueous liquid” includes, for example, body fluids of a mammal (for example, humans) such as isotonic fluid, water, blood, spinal fluid, plasma, serum, glass body fluid, and urine. An outer diameter of the embolic device  10  may be accommodated within inner diameters of the embolic device loading catheter  20  and the delivery catheter  40 , and may be substantially equal to the inner diameters of these catheters. A total length of the embolic device  10  is not particularly limited, and can be appropriately set depending on factors such as a size of the aneurysm to indwell in consideration of ease of loading and shortening of procedure time. 
     A constituent material from which the embolic device  10  may be fabricated is not particularly limited as long as the constituent material is a material that expands by absorbing at least a liquid such as blood, and has no (or extremely low) harmful effect on a human body even in a state of indwelling in the aneurysm. In addition, the embolic device  10  may be added or fabricated with a visualization material whose existing position in a living body can be confirmed by a confirmation method such as an X-ray, a fluorescent X-ray, an ultrasound, a fluorescence method, an infrared ray, or an ultraviolet ray. 
     Medical Instrument Set 
     Next, the configuration of the medical instrument set  100  according to the present embodiment will be described. As shown in  FIG.  1   , the medical instrument set  100  according to the present embodiment includes the embolic device loading catheter  20  and the delivery pusher  30 . 
     Embolic Device Loading Catheter 
     The embolic device loading catheter  20  can include an elongated catheter body  21  in which a loading lumen  22  is provided, a proximal hub  23  provided on a proximal side of the catheter body  21 , and a flexible tube  24  having one end connected to a proximal side of the proximal hub  23  and the other end connected to a port  26  of a three-way stopcock  25 . 
     The catheter body  21  can be a tubular member formed with a hole (the loading lumen  22 ) extending from an opening portion on a distal side of the catheter body  21  to an opening portion on the proximal side of the catheter body  21  along an axial direction. A length of the catheter body  21  in an extending direction can be appropriately defined, and it is sufficient that the catheter body  21  has a length at least capable of accommodating the embolic device  10 . 
     An inner diameter of the loading lumen  22  is designed to be substantially equal to an inner diameter of a sheath lumen  42  of the delivery catheter  40 . Accordingly, the outer diameter of the embolic device  10  is substantially equal to inner diameters of the embolic device loading catheter  20  and the delivery catheter  40 , and it is not necessary to reduce a diameter size of the embolic device  10  as in a direct insertion method and an indirect insertion method which can be assumed as a delivery method for the embolic device  10 . Therefore, when a required amount of the embolic device  10  indwells in the aneurysm, the number of inserted embolic devices  10  can be reduced, and procedure time can be shortened. 
     The embolic device loading catheter  20  is mainly provided in a state where the embolic device  10  is loaded in advance, and the embolic device  10  to be loaded into the catheter body  21  may be loaded into the catheter body  21  by the surgeon or the like grasping the embolic device  10 . As a method of loading the embolic device  10 , the surgeon can grip the embolic device  10  and insert the embolic device  10  from a distal connection portion  27  side or a proximal hub  23  side of the embolic device loading catheter  20 . 
     The catheter body  21  is connected (or mounted) by being engaged with a sheath hub  43  of the delivery catheter  40  in a state where the embolic device  10  is accommodated by an engagement portion  60 , which will be described later. In this connected state, the delivery pusher  30  is inserted from the proximal hub  23  to push the loaded embolic device  10  toward the delivery catheter  40 . 
     Since the embolic device loading catheter  20  is not inserted into a sheath of the delivery catheter  40  as in the direct insertion method, the embolic device loading catheter  20  does not require flexibility to follow a bent shape of a body lumen during insertion. Therefore, a constituent material from which the catheter body  21  may be fabricated is not particularly limited as long as the constituent material is a material that is at least more rigid than the delivery catheter  40  and provides an appropriate degree of hardness to prevent breakage of the loaded embolic device  10  during packaging or the like. As examples of the constituent material for the catheter body  21 , a resin material such as a polymer material including polyolefins (for example, polyethylene, polypropylene, polybutene, an ethylene-propylene copolymer, an ethylene-vinyl acetate copolymer, an ionomer, or a mixture of two or more types thereof), a polyolefin elastomer, a crosslinked polyolefin, polyvinyl chloride, polyamide, a polyamide elastomer, polyester, polyester elastomer, polyurethane, polyurethane elastomer, a fluorous resin, polycarbonate, polystyrene, polyacetal, polyimide, polyetherimide, and aromatic polyether ketone, or a mixture thereof, and a metal material such as a shape memory alloy, stainless steel, tantalum, titanium, platinum, gold, or tungsten can be suitably used. 
     Since it is sufficient that the catheter body  21  is more rigid than a sheath  41  from the viewpoint of preventing breakage of the embolic device  10 , in addition to making or fabricating the material for the catheter body  21  rigid, the catheter body  21  may be configured such that the catheter body  21  has a thickness so as not to be kinked when the same material as that of the sheath  41  is used. When the thickness is variable, an outer diameter of the catheter main body  21  is larger than an outer diameter of the sheath  41 , but since the embolic device loading catheter  20  is connected to the delivery catheter  40  via the engagement portion  60 , there is no particular problem. 
     The proximal hub  23  is an intermediate member that includes an insertion passage  23   a  (lumen) that allows communication between the loading lumen  22  of the catheter body  21  and the tube  24 , and allows a fluid (such as saline(or saline solution) for priming) flowing from the three-way stopcock  25  to flow to the catheter body  21  via the tube  24 . The embolic device  10  loaded into the loading lumen  22  is pushed toward the delivery catheter  40  by the delivery pusher  30  being inserted into the loading lumen  22  via the insertion passage  23   a  of the proximal hub  23 . 
     A constituent material from which the proximal hub  23  may be fabricated is not particularly limited as long as the constituent material is a hard material such as a hard resin. As examples of the constituent material for the proximal hub  23 , polyolefins such as polyethylene or polypropylene, polyamide, polycarbonate, or polystyrene can be suitably used. 
     A hemostasis valve is attached into the proximal side of the proximal hub  23 . As the hemostasis valve, for example, a substantially elliptical film-shaped (disk-shaped) valve body made of silicone rubber, latex rubber, butyl rubber, or isoprene rubber which is an elastic member may be used. 
     The one end of the tube  24  is interlocked to the proximal side of the proximal hub  23 , and the other end is interlocked to the port  26  of the three-way stopcock  25 . The tube  24  is a conduit through which a liquid such as saline or saline solution flowing out from a priming syringe interlocked to the port  26  flows. 
     A constituent material from which the tube  24  may be fabricated is not particularly limited as long as the constituent material is a flexible resin material in consideration of operability. As the constituent material for the tube  24 , polyolefins such as polyethylene, polypropylene, and ethylene-propylene copolymer, polyester such as polyethylene terephthalate, polystyrene, or polyvinyl chloride can be suitably used. 
     The three-way stopcock  25  communicates with the loading lumen  22  of the catheter body  21  via the insertion passage  23   a  of the proximal hub  23  and the tube  24 . In addition to a proximal side of the tube  24 , a priming syringe for priming the loading lumen  22  of the catheter body  21  can be connected to the port  26  of the three-way stopcock  25 . 
     As shown in  FIGS.  3  and  4   , a distal side of the embolic device loading catheter  20  is provided with the distal connection portion  27  that is connected to the sheath hub  43  of the delivery catheter  40 . The distal connection portion  27  is provided with a second engagement portion  28  that engages with a first engagement portion  48  provided on a proximal side of the sheath hub  43 . In the medical instrument set  100  according to the present embodiment, the first engagement portion  48  and the second engagement portion  28  constitute the engagement portion  60  for maintaining a connected state between the embolic device loading catheter  20  and the delivery catheter  40 . 
       FIGS.  3  and  4    show configuration examples of the engagement portion  60 . In the engagement portion  60  of each configuration, the first engagement portion  48  functions as a female portion, and the second engagement portion  28  functions as a male portion. 
     As shown in  FIG.  3 A , the engagement portion  60  may be configured such that the embolic device loading catheter  20  is fitted outside the delivery catheter  40 . In this configuration, the first engagement portion  48  is provided as a groove portion  48   a  provided along a circumferential direction on an outer circumferential surface of the sheath hub  43  on the proximal side. The second engagement portion  28  is provided as a separate collar member (collar) fixed on an outer circumferential surface of a distal portion of the catheter body  21 , and includes a plurality of engagement claws  28   a  provided so as to cover at least a part of the outer circumference of the distal portion of the catheter body  21 . As shown in  FIG.  3 B , the engagement portion  60  maintains the connected state between the embolic device loading catheter  20  and the delivery catheter  40  by the engagement claws  28   a  of the second engagement portion  28  fitted into the groove portion  48   a,  which is the first engagement portion  48 . When the embolic device loading catheter  20  and the delivery catheter  40  are in the connected state, the loading lumen  22  and the sheath lumen  42  communicate with each other. 
     As shown in  FIG.  4 A , the engagement portion  60  may be configured such that the embolic device loading catheter  20  is fitted inside the delivery catheter  40 . In this configuration, the first engagement portion  48  is provided as a groove portion  48   a  formed in an inner wall surface of an inserting portion  48   b,  which is a passage provided in a substantially central portion of an end surface of the sheath hub  43  on the proximal side. The second engagement portion  28  is provided as a separate skirt member fixed on the outer circumferential surface of the distal portion of the catheter body  21 , and includes a plurality of engagement claws  28   a  disposed so as to be able to fit into the groove portion  48   a  when the second engagement portion  28  protrudes in a distal direction and is inserted into the inserting portion  48   b.  As shown in  FIG.  4 B , the engagement portion  60  maintains the connected state between the embolic device loading catheter  20  and the delivery catheter  40  by the engagement claws  28   a  fitted into the groove portion  48   a.  When the embolic device loading catheter  20  and the delivery catheter  40  are in the connected state, the loading lumen  22  and the sheath lumen  42  communicate with each other. 
     A configuration of the engagement portion  60  is not limited to fitting forms shown in  FIGS.  3  and  4    as long as the connected state between the embolic device loading catheter  20  and the delivery catheter  40  is maintained, and can also employ other connection configurations, for example, such as a threaded type. The engagement portion  60  is configured to maintain a connected state between the embolic device loading catheter  20  and the delivery catheter  40 , and prevents the connected state of the embolic device loading catheter  20  and the delivery catheter  40  from being detached during the procedure. However, the embolic device loading catheter  20  and the delivery catheter  40  do not necessarily have to be engaged via the engagement portion  60 . For example, a state where the distal connection portion  27  is inserted into the sheath hub  43  may be the connected state between the embolic device loading catheter  20  and the delivery catheter  40 . 
     As shown in  FIG.  5   , the inner diameter of the loading lumen  22  is designed to be substantially equal to the inner diameter of the sheath lumen  42 , and accordingly, the outer diameter of the embolic device  10  is also designed, and the embolic device  10  can have a diameter size larger than that of the direct insertion method or the indirect insertion method. Accordingly, in the endoleak embolization, the number of inserted embolic device  10  can be reduced, and as a result, the procedure time can be shortened. Since the inner diameter of the loading lumen  22  is substantially equal to the inner diameter of the sheath lumen  42 , in the connected state between the embolic device loading catheter  20  and the delivery catheter  40  caused by the engagement portion  60 , a step (clearance) between an opening portion of a distal contact portion  27   b  and an opening portion on a proximal side of a communication distal portion  43   b  can be made close to zero. Therefore, when a pusher body  31  of the delivery pusher  30  is inserted into the sheath lumen  42  from the loading lumen  22 , the embolic device  10  can be smoothly moved from the embolic device loading catheter  20  to the delivery catheter  40 . 
     The distal connection portion  27  includes an insertion portion  27   a  that is inserted into a communicating enlarged-diameter portion  43   c  provided inside the sheath hub  43  when the embolic device loading catheter  20  and the delivery catheter  40  are in the connected state. In the connected state between the embolic device loading catheter  20  and the delivery catheter  40 , the insertion portion  27   a  is inserted into the sheath hub  43  such that the loading lumen  22  and the sheath lumen  42  are aligned in the axial direction. Accordingly, the embolic device  10  is pushed out to the sheath lumen  42  without being exposed to an outside from the loading lumen  22  via the sheath hub  43 . 
     In the connected state between the embolic device loading catheter  20  and the delivery catheter  40 , the insertion portion  27   a  includes the distal contact portion  27   b,  on a distal side of the insertion portion  27   a,  that comes into contact with an inner surface of a tapered portion  43   d  provided in the communicating enlarged-diameter portion  43   c.  When the insertion portion  27   a  is inserted into the communicating enlarged-diameter portion  43   c,  the distal contact portion  27   b  comes into contact with the tapered portion  43   d,  so that the loading lumen  22  and the sheath lumen  42  communicate with each other so as not to intersect with other spaces including a space of the communicating enlarged-diameter portion  43   c.  Therefore, when the embolic device  10  is pushed out from the embolic device loading catheter  20  into the delivery catheter  40 , the embolic device  10  can be prevented from being damaged (for example, bent or crushed on a distal side) due to abutment of the embolic device  10  against an inner wall surface of the sheath hub  43 , can be prevented from being erroneously inserted into other spaces within the sheath hub  43  (for example, erroneously entering into a tube  44  connected to the sheath hub  43 ), and can be reliably injected into the sheath lumen  42 . 
     Delivery Pusher 
     The delivery pusher  30  is an elongated rod-shaped member inserted into the proximal hub  23  and configured to push out the embolic device  10  accommodated in the catheter body  21  and deliver the embolic device  10  into the aneurysm via the sheath lumen  42  of the delivery catheter  40 . The delivery pusher  30  can include the rod-shaped pusher body  31  and a handle portion  32  provided on a proximal side of the pusher body  31  and held by the surgeon when the embolic device  10  is to be delivered into the aneurysm. 
     In a state where the embolic device loading catheter  20  is connected to the delivery catheter  40 , when the surgeon performs a predetermined operation while gripping the handle portion  32 , the delivery pusher  30  pushes the embolic device  10  loaded in the loading lumen  22  into the aneurysm via the sheath lumen  42  of the delivery catheter  40 . Specifically, the delivery pusher  30  is pushed out along axial directions of the embolic device loading catheter  20  and the delivery catheter  40  to push out the embolic device  10  loaded in the embolic device loading catheter  20  to an outside (into the aneurysm). 
     In the connected state where the embolic device loading catheter  20  is connected to the delivery catheter  40 , a body length of the pusher body  31  of the delivery pusher  30  is longer than a distance from a proximal end of the insertion passage  23   a  of the proximal hub  23  to the distal end opening  41   a  of the sheath  41  of the delivery catheter  40  (an opening portion on a distal side communicating with the sheath lumen  42 ). Therefore, in the state where the embolic device loading catheter  20  is connected to the delivery catheter  40 , when the delivery pusher  30  is inserted from the proximal hub  23 , the embolic device  10  loaded in the loading lumen  22  can be passed through the insertion passage  23   a  into the sheath hub  43 , and then the embolic device  10  can be passed into the sheath lumen  42  and pushed out into the aneurysm by a single push-out operation. 
     As shown in  FIG.  6 A , the handle portion  32  has a substantially mushroom shape having a large-diameter head portion  32   a  on a distal side and a small-diameter handle portion  32   b  extending to a proximal side of the large-diameter head portion  32   a,  and an outer diameter dimension of the large-diameter head portion  32   a,  which is a maximum outer diameter of the handle portion  32 , is designed to be larger than an inner diameter dimension of the insertion passage  23   a  of the proximal hub  23 . Accordingly, as shown in  FIG.  6 B , when the delivery pusher  30  is inserted into the embolic device loading catheter  20 , since the large-diameter head portion  32   a  is not inserted into the insertion passage  23   a  of the proximal hub  23 , an insertion length of the delivery pusher  30  can be limited. Since the handle portion  32  does not enter the proximal hub  23  due to the large-diameter head portion  32   a,  when the push-out operation of the embolic device  10  by the delivery pusher  30  is completed, the handle portion  32  can be rather easily pulled out simultaneously in the inserted state in accordance with a detachment operation of the embolic device loading catheter  20 , thereby simplifying a detachment operation. The delivery pusher  30  may be pulled out from the embolic device loading catheter  20  before the detachment operation of the embolic device loading catheter  20 . 
     The handle portion  32  may be configured such that the large-diameter head portion  32   a  can be fitted to the proximal side of the proximal hub  23  when the handle portion  32  is inserted into the embolic device loading catheter  20 . With such a configuration, when the embolic device loading catheter  20  is detached, the delivery pusher  30  can be rather reliably pulled out without being detached from the embolic device loading catheter  20 . 
     A constituent material from which the pusher body  31  may be fabricated is not particularly limited as long as the constituent material is a material having appropriate hardness and flexibility such that the embolic device  10  can be conveyed. As examples of the constituent material for the pusher body  31 , a resin material such as a polymer material including polyolefins (for example, polyethylene, polypropylene, polybutene, an ethylene-propylene copolymer, an ethylene-vinyl acetate copolymer, an ionomer, or a mixture of two or more types thereof), a polyolefin elastomer, a crosslinked polyolefin, polyvinyl chloride, polyamide, a polyamide elastomer, polyester, polyester elastomer, polyurethane, polyurethane elastomer, a fluorous resin such as ETFE, polycarbonate, polystyrene, polyacetal, polyimide, polyetherimide, and aromatic polyether ketone, or a mixture thereof, and a metal material such as a shape memory alloy, stainless steel, tantalum, titanium, platinum, gold, or tungsten can be suitably used. 
     Delivery System 
     Next, the delivery system  200  according to the present embodiment will be described. As shown in  FIG.  1   , the delivery system  200  according to the present embodiment can include, in addition to the medical instrument set  100 , the delivery catheter  40  to and from which the embolic device loading catheter  20  is attached and detached while indwelling in the body lumen. 
     The delivery catheter  40  can also use, for example, an existing catheter that can indwell in the body lumen. Therefore, in the delivery system  200  according to the present embodiment, the medical instrument set  100  and the delivery catheter  40  can be sold as a set and supplied to a market, but even when only the medical instrument set  100  is sold and supplied to the market, an existing catheter can be used as the delivery catheter  40  to function as the delivery system  200 . 
     Delivery Catheter 
     The delivery catheter  40  can include, for example, the sheath  41  formed of an elongated tubular member in which a hole (the sheath lumen  42 ) extending from an opening portion on a distal side of the delivery catheter  40  to an opening portion on a proximal side of the delivery catheter  40  along an axial direction is formed, and indwells in the body lumen and functions as an introduction passage for delivering the embolic device  10  into the aneurysm. A main body  51  of an insertion assisting member  50 , which will be described later, can be inserted through the sheath  41  over a total length of the sheath  41 . Therefore, a length of the sheath  41  in the axial direction is set to be at least shorter than a length of the main body  51  of the insertion assisting member  50 . 
     As shown in  FIG.  5   , the inner diameter of the sheath lumen  42  is designed to be substantially equal to the inner diameter of the loading lumen  22 . Accordingly, the embolic device  10  can be relatively smoothly moved from the loading lumen  22  to the sheath lumen  42  when the embolic device loading catheter  20  and the delivery catheter  40  are in the connected state by the engagement portion  60 . 
     A constituent material from which the sheath  41  may be fabricated is not particularly limited as long as the constituent material is flexible and rigid enough to follow the bent shape of the body lumen such as meandering and bending. As examples of the constituent material for the sheath  41 , a resin material such as a polymer material including polyolefins (for example, polyethylene, polypropylene, polybutene, an ethylene-propylene copolymer, an ethylene-vinyl acetate copolymer, an ionomer, or a mixture of two or more types thereof), a polyolefin elastomer, a crosslinked polyolefin, polyvinyl chloride, polyamide, a polyamide elastomer, polyester, polyester elastomer, polyurethane, polyurethane elastomer, a fluorous resin, polycarbonate, polystyrene, polyacetal, polyimide, polyetherimide, and aromatic polyether ketone, or a mixture thereof can be suitably used. 
     The delivery catheter  40  includes the sheath hub  43  interlocked to the proximal side of the sheath  41 , and the flexible tube  44  having one end connected to the proximal side of the sheath hub  43  and the other end connected to a three-way stopcock  45 . 
     The sheath hub  43  is an intermediate member that includes a communication passage  43   a  that allows communication between the sheath lumen  42  and the tube  44  and between the loading lumen  22  and the sheath lumen  42 , and allows a fluid (such as saline (or saline solution) for priming) flowing from the three-way stopcock  45  to flow to the sheath  41  via the tube  44  and to guide the embolic device  10  pushed out from the embolic device loading catheter  20  into the sheath lumen  42 . The insertion assisting member  50  is inserted into the sheath hub  43  when the delivery catheter  40  indwells in the body lumen. 
     A constituent material from which the sheath hub  43  may be fabricated may be the same as the material exemplified as the constituent material for the proximal hub  23  described above. 
     The communication passage  43   a  includes the communication distal portion  43   b  having an inner diameter substantially equal to the inner diameter of the sheath lumen  42 , and the communicating enlarged-diameter portion  43   c  extending from the communication distal portion  43   b  in a proximal direction and serving as an internal space having a diameter larger than that of the communication distal portion  43   b.  The tapered portion  43   d  increased in diameter in the proximal direction from an opening portion on the proximal side of the communication distal portion  43   b  is provided in a portion of the communicating enlarged-diameter portion  43   c  connected to the communication distal portion  43   b.    
     In the connected state between the embolic device loading catheter  20  and the delivery catheter  40 , a distal end of the loading lumen  22  is inserted so as to be adjacent to the opening portion on the proximal side of the communication distal portion  43   b.  Accordingly, when the embolic device  10  is pushed out from the embolic device loading catheter  20  into the delivery catheter  40 , the embolic device  10  can be emitted from the loading lumen  22  into the sheath lumen  42  without being exposed to the outside. 
     The insertion state of the insertion portion  27   a  is preferably such that the inner surface of the tapered portion  43   d  and the distal contact portion  27   b  come into contact with each other so that the loading lumen  22  and the sheath lumen  42  are aligned in the axial direction. Accordingly, since a distal end of the insertion portion  27   a  and the opening portion on the proximal side of the communication distal portion  43   b  are connected along the axial direction, the pushed-out embolic device  10  can be prevented from being damaged (for example, be bent or crushed on the distal side) due to abutment of the embolic device  10  against the inner wall surface of the sheath hub  43 , and the loading lumen  22  and the sheath lumen  42  are communicated with each other so as not to intersect with a space inside the communicating enlarged-diameter portion  43   c,  thereby preventing the embolic device  10  from being erroneously inserted into other spaces within the sheath hub  43  (for example, erroneously entering into the tube  44  connected to the sheath hub  43 ). 
     As shown in  FIGS.  3  and  4   , the proximal side of the sheath hub  43  is provided with the first engagement portion  48  to be engaged with the second engagement portion  28  provided at the distal connection portion  27  of the embolic device loading catheter  20 . 
     For example, the first engagement portion  48  may be configured by the groove portion  48   a  into which the engagement claws  28   a  of the second engagement portion  28  described above are fitted. The groove portion  48   a  is provided along the circumferential direction on the outer circumferential surface of the sheath hub  43  on the proximal side in  FIG.  3   , and is provided along a circumferential direction on the inner wall surface of the inserting portion  48   b  formed in a substantially central portion of the end surface of the sheath hub  43  on the proximal side in  FIG.  4   . 
     The one end of the tube  44  is interlocked to the proximal side of the sheath hub  43 , and the other end is interlocked to the port  46  of the three-way stopcock  45 . The tube  44  is a conduit through which a liquid such as a saline (or saline solution) flows from a priming syringe interlocked to the port  46 . A constituent material from which the tube  44  may be fabricated may be the same as the material exemplified as the constituent material for the tube  24  described above. 
     The three-way stopcock  45  communicates with the sheath lumen  42  of the sheath  41  via the communication passage  43   a  of the sheath hub  43  and the tube  44 . In addition to a proximal side of the tube  44 , a priming syringe for priming the sheath lumen  42  of the sheath  41  and a liquid agent injection syringe for injecting a contrast agent, a drug, or the like can be connected to the port  46  of the three-way stopcock  45 . 
     A hemostasis valve  47  can be attached into the proximal side of the sheath hub  43 . As the hemostasis valve  47 , for example, a substantially elliptical film-shaped (disk-shaped) valve body made of silicone rubber, latex rubber, butyl rubber, or isoprene rubber which is an elastic member may be used. When the embolic device loading catheter  20  is connected to the delivery catheter  40 , at least the distal contact portion  27   b  of the insertion portion  27   a  passes through the hemostasis valve  47  and is inserted into the communicating enlarged-diameter portion  43   c.    
     Here, an example of dimensions of each device constituting the delivery system  200  according to the present embodiment will be described. Numerical values shown below are merely examples, and the present disclosure is not limited thereto. 
     In the delivery system  200  according to the present embodiment, when the delivery catheter  40  is a catheter having an outer diameter of 6 Fr (an inner diameter of 1.8 mm) and a surgical method to be applied is endoleak embolization for stent graft interpolation of an abdominal aortic aneurysm (AAA), the outer diameter of the embolic device  10  can be, for example, 0.4 mm to 1.9 mm (preferably about 1.6 mm), and the inner diameter of the embolic device loading catheter  20  can be, for example, 1.0 mm to 1.8 mm (preferably about 1.8 mm), which is equal to the inner diameter of the delivery catheter  40 . A body length of the catheter body  21  of the embolic device loading catheter  20  can be, for example, 30 cm to 105 cm (preferably about 42 cm), a body length of the sheath  41  of the delivery catheter  40  can be, for example, 39 cm to 90 cm (preferably about 47 cm), and a body length of the pusher body  31  of the delivery pusher  30  can be, for example, 79 cm to 205 cm (preferably about 96 cm). The total length of the embolic device  10  is appropriately determined depending on a size of the aneurysm, and may be in a range, for example, of 30 cm to 100 cm (preferably about 40 cm) from the viewpoint of ease of loading into the embolic device loading catheter  20  and shortening the procedure time. 
     Embolic Device Delivery Medical System 
     Next, the embolic device delivery medical system  300  according to the present embodiment will be described. As shown in  FIG.  2   , the embolic device delivery medical system  300  according to the present embodiment can include, in addition to the delivery system  200 , the insertion assisting member  50  that delivers the delivery catheter  40  into the body lumen. 
     Insertion Assisting Member 
     The insertion assisting member  50  is an auxiliary tool that is provided with a guide wire lumen  52  that is inserted from a distal side to a proximal side along an axial direction of the main body  51 , and assists insertion when the delivery catheter  40  is delivered into the aneurysm along a guide wire inserted in advance into the body lumen. 
     The insertion assisting member  50  is inserted into and assembled to the delivery catheter  40  in order to help prevent bending or the like when the delivery catheter  40  is inserted into the body lumen. The guide wire lumen  52  has an inner diameter smaller than that of the sheath lumen  42  of the delivery catheter  40 . Therefore, when the delivery catheter  40  is delivered into the aneurysm, axial deviation of the delivery catheter  40  with respect to the guide wire can be reduced, which makes delivery relatively easier. 
     A constituent material from which the insertion assisting member  50  may be fabricated is not particularly limited as long as the constituent material is harder and more flexible than a constituent material for the delivery catheter  40 . As an example of the constituent material for the insertion assisting member  50 , polyolefins such as polyethylene or polypropylene, polyester such as polyamide or polyethylene terephthalate, a fluorous resin such as ETFE, a resin material such as PEEK (polyether ether ketone) or polyimide, a metal material such as a shape memory alloy, stainless steel, tantalum, titanium, platinum, gold, or tungsten can be suitably used. 
     Operations 
     Next, an operation of the embolic device delivery medical system  300  according to the present embodiment will be described with reference to  FIGS.  7 A to  7 G . Here, an operation example when the embolic device delivery medical system  300  is applied to the endoleak embolization for the stent graft interpolation of the abdominal aortic aneurysm (AAA) is described, and configuration examples of the engagement portion  60  are shown in  FIGS.  3 A and  3 B . In each drawing, the inside of the aneurysm is represented by “A”, the inside of the blood vessel is represented by “V”, the outside of the body is represented by “ 0 ”, and installation positions of the devices of the embolic device delivery medical system  300  are expressed so as to be systematically grasped. 
     First, as a preparation step before surgery, as shown in  FIG.  7 A , the surgeon percutaneously inserts, from a limb of a patient serving as a puncture site into the body lumen via an introducer (for example, a member indicated by a two-dot chain line in  FIG.  7 A ), the sheath  41  of the delivery catheter  40  into which the insertion assisting member  50  is inserted, and delivers a distal end opening  41   a  of the delivery catheter  40  to the abdominal aortic aneurysm. When the distal end opening  41   a  is delivered into the aneurysm, the insertion assisting member  50  is removed. The delivery catheter  40  may be delivered to an aneurysm lesion by using the guide wire inserted in the aneurysm in advance without using the insertion assisting member  50 . 
     Next, as shown in  FIG.  7 B , the surgeon inserts, into the body lumen via the introducer, a catheter (a stent graft device) into which a stent graft SG is compressed and inserted, and moves the catheter to the aneurysm lesion using the guide wire inserted in advance into the aneurysm. Thereafter, the stent graft SG is expanded from the catheter and indwells in the target lesion. Accordingly, as shown in  FIG.  7 B , the delivery catheter  40  can be inserted between a leg of the stent graft SG and a blood vessel wall, a distal portion of the delivery catheter  40  can be inserted between the stent graft SG and a blood vessel wall of the aneurysm, that is, into the aneurysm, and the delivery catheter  40  indwells in the body lumen with the distal end opening  41   a  positioned in the aneurysm. 
     As shown in  FIG.  7 C , the embolic device loading catheter  20  loaded with the embolic device  10  is prepared.  FIG.  7 C  shows a state before the embolic device loading catheter  20  is connected to the delivery catheter  40 . 
     When the delivery catheter  40  indwells, the surgeon connects the distal connection portion  27  of the embolic device loading catheter  20  to a proximal end of the sheath hub  43  of the delivery catheter  40 , as shown in  FIG.  7 D . At this time, as shown in  FIG.  3 B , the distal contact portion  27   b  of the distal connection portion  27  is inserted into the communicating enlarged-diameter portion  43   c  of the sheath hub  43  and comes into contact with the inner surface of the tapered portion  43   d.  Accordingly, the distal end of the loading lumen  22  can be adjacent to the communication distal portion  43   b,  and an axis of the loading lumen  22  and an axis of the sheath lumen  42  can be aligned. 
     Next, the surgeon inserts a distal end of the pusher body  31  from the proximal side of the proximal hub  23  while gripping the handle portion  32 , as shown in  FIG.  7 E . A distal end of the delivery pusher  30  inserted from the proximal hub  23  comes into contact with a proximal end of the embolic device  10  loaded in the embolic device loading catheter  20 , and the embolic device  10  is pushed out and moved to the sheath lumen  42  of the delivery catheter  40  by the push-out operation. 
     As shown in  FIG.  7 F , the surgeon pushes out the delivery pusher  30  inserted from the proximal hub  23  to push out the embolic device  10  from the sheath lumen  42  into the aneurysm. Thereafter, the surgeon detaches the emptied embolic device loading catheter  20  together with the delivery pusher  30  from the delivery catheter  40 , as shown in  FIG.  7 G . The delivery pusher  30  can be detached from the delivery catheter  40  while being inserted into the embolic device loading catheter  20 . Thus, a first insertion operation of the embolic device  10  into the aneurysm is completed. In the insertion operation, the delivery pusher  30  may be pulled out from the embolic device loading catheter  20  before the detachment operation of the embolic device loading catheter  20 . Such a series of embolic device indwelling operations shown in  FIGS.  7 C to  7 G  are repeated until a required amount (or desired amount) of embolic device  10  is loaded into the aneurysm. The required amount (or desired amount) of the embolic device  10  can be calculated as a value obtained by calculating a volume of the aneurysm based on CT data about the patient and subtracting the volume of the stent graft SG when the stent graft SG is expanded in the aneurysm from the calculated value. 
     After the required amount of embolic device  10  has indwelled in the aneurysm, the surgeon pulls out the delivery catheter  40  from the aneurysm and the body lumen. At this time, the delivery catheter  40  may be pulled out from the aneurysm and the body lumen in a state where the embolic device loading catheter  20  is connected to the delivery catheter  40  and the delivery pusher  30  is inserted into the delivery catheter  40 . Before the delivery catheter  40  is pulled out from the aneurysm and the body lumen, the delivery pusher  30  may be pulled out from the delivery catheter  40  while the embolic device loading catheter  20  is detached from the delivery catheter  40 . Before the delivery catheter  40  is pulled out from the aneurysm and the body lumen, the delivery pusher  30  may be pulled out from the delivery catheter  40  and the embolic device loading catheter  20 , and then the embolic device loading catheter  20  may be detached from the delivery catheter  40 . In any case, the introducer remains indwelled in the body lumen for additional expansion of the stent graft SG by a balloon after the embolic device  10  indwells, an imaging operation, and the like. 
     Thereafter, the embolic device  10  indwelling in the aneurysm comes into contact with a liquid such as blood in the aneurysm and gradually swells, and the completely expanded embolic device  10  fills a space between an inner surface of the aneurysm and an outer surface of the stent graft, thereby closing the aneurysm. Accordingly, the aneurysm is prevented from rupture. 
     As described above, the embolic device delivery medical system  300  including the medical instrument set  100  and the delivery system  200  according to the present embodiment can deliver, for example, the embolic device  10  into the aneurysm only in three procedures as shown in  FIGS.  7 A to  7 C . Therefore, the number of procedure steps can be reduced, and the procedure time can be shortened as compared with the indirect insertion method which can be assumed as the delivery method of the embolic device  10 . 
     Modification 
     The embodiment described above can also be modified to have the following configuration. 
       FIG.  8    shows another configuration example of the insertion portion  27   a  of the distal connection portion  27  in the embolic device loading catheter  20 . As shown in  FIG.  8 A , the insertion portion  27   a  according to a modification includes a bending portion  27   c.  The bending portion  27   c  forms at least a part of the insertion portion  27   a,  and has a shape that is gradually bent in a direction away from a central axis of the loading lumen  22  (a radial direction with respect to the central axis of the loading lumen  22 ) toward a distal side of the loading lumen  22  (the distal contact portion  27   b ). The bending portion  27   c  may be provided, for example, in a region partitioned by a two-dot chain line shown in  FIG.  8 A  in the insertion portion  27   a  of the embolic device loading catheter  20 . In the shown example, a part of an intermediate portion located between a proximal end of the insertion portion  27   a  and the distal contact portion  27   b  (an opening portion of the distal end) is formed by the bending portion  27   c,  and is bent in a bent shape. 
     As shown in  FIG.  8 B , when the bending portion  27   c  is inserted into the communicating enlarged-diameter portion  43   c  of the sheath hub  43 , the bent shape of the bending portion  27   c  is corrected into a substantially straight state. In the connected state where the embolic device loading catheter  20  is connected to the delivery catheter  40 , the bending portion  27   c  is corrected such that the axis of the loading lumen  22  and the axis of the sheath lumen  42  of the delivery catheter  40  are aligned in a state where the distal contact portion  27   b  is in contact with the inner surface of the tapered portion  43   d  of the sheath hub  43 . That is, when the bending portion  27   c  is inserted into the communicating enlarged-diameter portion  43   c,  the bending portion  27   c  comes into contact with an inner wall or the like of the communicating enlarged-diameter portion  43   c,  whereby the bent shape of the bending portion  27   c  is corrected into a substantially straight shape. In particular, the distal contact portion  27   b  comes into contact with the inner wall of the communicating enlarged-diameter portion  43   c,  and a proximal portion of the insertion portion  27   a  comes into contact with the hemostasis valve  47  of the sheath hub or the inner wall of the opening portion on a proximal side of the sheath hub, whereby the bending portion  27   c  is corrected into a substantially straight shape. 
     The bending portion  27   c  has a bent shape with a predetermined curvature smoothly deformed in an arch shape from the proximal end of the insertion portion  27   a  to the distal contact portion  27   b  (an opening portion of the distal end) or from the intermediate portion of the insertion portion  27   a  to the distal contact portion  27   b  (an opening portion of the distal end), and also has a bent shape such as a substantially bent shape bent from a certain starting point. 
     A constituent material from which the bending portion  27   c  may be fabricated is not particularly limited as long as the constituent material has flexibility such that the bending portion  27   c  keeps a bent state before being inserted into the sheath hub  43 , comes into contact with the inner wall or the like of the communicating enlarged-diameter portion  43   c  and can be elastically deformed into a substantially straight state after being inserted into the sheath hub  43 . Since the bending portion  27   c  only needs to have lower rigidity than the sheath hub  43 , in order to produce a difference in rigidity, the bending portion  27   c  may be structured by changing the constituent material, or by changing a thickness of the bending portion  27   c  when the same material is employed. 
     Thus, by providing the bending portion  27   c  in at least a part of the insertion portion  27   a,  it is possible to prevent the embolic device  10  loaded in the loading lumen  22  from erroneously falling off from a distal end of the distal connection portion  27 . When the bending portion  27   c  is inserted into the sheath hub  43 , the bent shape of the bending portion  27   c  is corrected to a substantially straight state, so that the axis of the loading lumen  22  and the axis of the sheath lumen  42  are aligned. 
     Therefore, even if the insertion portion  27   a  is partially bent, the insertion of the embolic device  10  is not hindered. 
     Functions and Effects 
     As described above, the medical instrument set  100  according to the present embodiment is configured to deliver the embolic device  10  into an aneurysm via the delivery catheter  40 . The delivery catheter  40  includes the sheath  41  that includes the sheath lumen  42  and the distal end opening  41   a  that communicates with the sheath lumen  42 , and the sheath hub  43  that includes the communication passage  43   a  communicating with a proximal end of the sheath lumen  42  and is provided on the proximal side of the sheath  41 . The medical instrument set  100  includes: the embolic device loading catheter  20  that includes the catheter body  21  including the loading lumen  22  having an open distal end, and the proximal hub  23  including the insertion passage  23   a  communicating with a proximal end of the loading lumen  22 , and in which the embolic device  10  is loaded in the loading lumen  22 ; and the delivery pusher  30  that includes the elongated pusher body  31  insertable into the loading lumen  22  through the insertion passage  23   a  of the proximal hub  23  of the embolic device loading catheter  20 . The catheter body  21  includes the distal connection portion  27  attachable to and detachable from the sheath hub  43  of the delivery catheter  40  on the distal side of the catheter body  21 . The pusher body  31  has a body length longer than a distance from the proximal end of the insertion passage  23   a  of the proximal hub  23  to the distal end opening  41   a  of the sheath  41  of the delivery catheter  40  in the connected state where the distal connection portion  27  of the catheter body  21  is connected to the sheath hub  43  of the delivery catheter  40 , and when the pusher body  31  is inserted from the insertion passage  23   a  of the proximal hub  23  in the connected state, the embolic device  10  is passed through the sheath lumen  42  of the delivery catheter  40  and is pushed out from the distal end opening  41   a  of the delivery catheter  40  into the aneurysm. 
     The pusher body  31  of the delivery pusher  30  is formed so as to be longer than the distance from the proximal end of the insertion passage  23   a  of the proximal hub  23  to the distal end opening  41   a  of the sheath  41  of the delivery catheter  40  in the connected state between the embolic device loading catheter  20  and the delivery catheter  40 . Therefore, in the connected state where the embolic device loading catheter  20  is connected to the delivery catheter  40 , by inserting the delivery pusher  30  from the proximal hub  23 , the embolic device  10  loaded in the loading lumen  22  can be pushed out into the aneurysm by a single push-out operation. Therefore, the number of procedure steps can be reduced. In addition, since it is only necessary to connect the embolic device loading catheter  20  to the sheath hub  43  of the delivery catheter  40 , the procedure can be simplified, and as a result, the procedure time can be shortened. 
     In the medical instrument set  100  according to the present embodiment, preferably, the inner diameter of the loading lumen  22  may be substantially equal to the inner diameter of the sheath lumen  42 . 
     With such a configuration, the outer diameter of the embolic device  10  loaded into the loading lumen  22  can be made substantially equal to the inner diameters of the loading lumen  22  and the sheath lumen  42 . Therefore, the diameter size of the embolic device  10  can be made large without being made small in accordance with the loading lumen  22  as in the direct insertion method and the indirect insertion method, so that the number of inserted embolic device  10  can be reduced and the procedure time can be shortened. 
     In the medical instrument set  100  according to the present embodiment, preferably, the distal connection portion  27  of the catheter body  21  may include the insertion portion  27   a  that is inserted into the sheath hub  43  of the delivery catheter  40  in the connected state. 
     With such a configuration, when the embolic device loading catheter  20  is connected to the delivery catheter  40 , the insertion portion  27   a  can be inserted into the sheath hub  43 , so that the embolic device  10  can be pushed out from the loading lumen  22  to the sheath lumen  42  via the sheath hub  43  without being exposed to the outside. 
     In the medical instrument set  100  according to the present embodiment, preferably, the delivery pusher  30  may include the handle portion  32  provided on the proximal side of the pusher body  31 , and the maximum outer diameter of the handle portion  32  may be larger than an inner diameter of the insertion passage  23   a  of the proximal hub  23 . 
     With such a configuration, when the delivery pusher  30  is inserted into the embolic device loading catheter  20 , since a distal end of the handle portion  32  (the large-diameter head portion  32   a ) is not inserted into the insertion passage  23   a  of the proximal hub  23 , an insertion length of an insertion pusher of the delivery pusher  30  can be limited. Since the handle portion  32  does not enter the proximal hub  23 , when the push-out operation of the embolic device  10  by the delivery pusher  30  is completed, the delivery pusher  30  can be rather easily pulled out simultaneously with the detachment operation of the embolic device loading catheter  20 . 
     The delivery system  200  according to the present embodiment includes the medical instrument set  100  and the delivery catheter  40 , and is configured such that, in the connected state, the embolic device  10  is passed through the sheath lumen  42  of the delivery catheter  40  by the delivery pusher  30  inserted from the insertion passage  23   a  of the proximal hub  23  and is pushed out from the distal end opening  41   a  of the delivery catheter  40  into the aneurysm. 
     When the distal connection portion  27  of the embolic device loading catheter  20  is engaged with the sheath hub  43  of the delivery catheter  40  indwelling in the body lumen to be in the connected state, the loading lumen  22  and the sheath lumen  42  are in communication with each other through the communication passage  43   a  of the sheath hub  43 . Therefore, by inserting the delivery pusher  30  from the proximal hub  23 , the embolic device  10  loaded in the loading lumen  22  can be pushed out into the aneurysm by a single push-out operation. 
     The delivery system  200  according to the present embodiment may be configured such that, preferably, the delivery catheter  40  includes the first engagement portion  48  including the groove portion  48   a  provided on the proximal side of the sheath hub  43 , the embolic device loading catheter  20  includes the second engagement portion  28  including the engagement claws  28   a  to be engaged with the first engagement portion  48  in the distal connection portion  27 , and the first engagement portion  48  and the second engagement portion  28  are engaged with each other in the connected state to allow communication between the loading lumen  22  and the sheath lumen  42 . 
     In the delivery system  200 , since the second engagement portion  28  including the plurality of engagement claws  28   a  provided in the delivery catheter  40  is engaged with the groove portion  48   a,  which is the first engagement portion  48  provided in the embolic device loading catheter  20 , the embolic device loading catheter  20  is attachable to and detachable from the delivery catheter  40 . Therefore, after the embolic device  10  is pushed out into the aneurysm by the push-out operation, by releasing an engagement state between the first engagement portion  48  and the second engagement portion  28 , it is possible to rather easily restart an indwelling operation of the embolic device  10  including the push-out operation by connecting (mounting) another embolic device loading catheter  20  in which the embolic device  10  has been loaded or reloading the embolic device  10  into the embolic device loading catheter  20  which has been detached. 
     The delivery system  200  according to the present embodiment may be configured such that, preferably, the communication passage  43   a  of the sheath hub  43  of the delivery catheter  40  includes the communication distal portion  43   b  having the inner diameter substantially equal to the inner diameter of the sheath lumen  42 , and the communicating enlarged-diameter portion  43   c  extending from the communication distal portion  43   b  in the proximal direction and having a diameter larger than that of the communication distal portion  43   b,  and the distal connection portion  27  of the catheter body  21  includes the distal end of the loading lumen  22  and includes the insertion portion  27   a  to be inserted into the communicating enlarged-diameter portion  43   c  of the sheath hub  43  in the connected state. 
     Since the insertion portion  27   a  is inserted such that the loading lumen  22  and the sheath lumen  42  are aligned in the axial direction in the connected state between the embolic device loading catheter  20  and the delivery catheter  40 , the embolic device  10  is pushed out to the sheath lumen  42  from the loading lumen  22  without being exposed to the outside through the sheath hub  43 . 
     The delivery system  200  according to the present embodiment may be configured such that, preferably, the communicating enlarged-diameter portion  43   c  includes the tapered portion  43   d  enlarged in diameter in the proximal direction, and the insertion portion  27   a  of the distal connection portion  27  includes the distal contact portion  27   b  that comes into contact with the inner surface of the tapered portion  43   d  such that the axis of the loading lumen  22  and the axis of the sheath lumen  42  of the delivery catheter  40  are aligned in the connected state. 
     When the insertion portion  27   a  is inserted into the communicating enlarged-diameter portion  43   c,  if the distal contact portion  27   b  comes into contact with the tapered portion  43   d,  the loading lumen  22  and the sheath lumen  42  communicate with each other so as not to intersect with other spaces including the space of the communicating enlarged-diameter portion  43   c.  Therefore, when the embolic device  10  is pushed out from the embolic device loading catheter  20  into the delivery catheter  40 , the embolic device  10  is prevented from being damaged (for example, bent or crushed on the distal side) due to abutment of the embolic device  10  against the inner wall surface of the sheath hub  43 , is prevented from being erroneously inserted into other spaces within the sheath hub  43  (for example, erroneously entering into the tube  44  connected to the sheath hub  43 ), and is reliably delivered into the aneurysm. 
     The delivery system  200  according to the present embodiment may be configured such that, preferably, the insertion portion  27   a  includes the bending portion  27   c  that is gradually bent away from the axial direction of the loading lumen  22  toward the distal end of the loading lumen  22  (distal contact portion  27   b ), and when the insertion portion  27   a  is inserted into the sheath hub  43 , the bent shape of the bending portion  27   c  is corrected, and in the connected state, the distal contact portion  27   b  and the inner surface of the tapered portion  43   d  come into contact with each other, and the axis of the loading lumen  22  and the axis of the sheath lumen  42  of the delivery catheter  40  are aligned. 
     By providing the bending portion  27   c  in at least a part of the insertion portion  27   a,  it is possible to prevent the embolic device  10  loaded in the loading lumen  22  from erroneously falling off from the distal end of the distal connection portion  27 . When the bending portion  27   c  is inserted into the sheath hub  43 , the bent shape of the bending portion  27   c  is corrected to a substantially straight state. Therefore, since the axis of the loading lumen  22  and the axis of the sheath lumen  42  are aligned in the connected state between the embolic device loading catheter  20  and the delivery catheter  40 , the insertion of the embolic device  10  is not hindered. 
     The delivery system  200  according to the present embodiment may be configured such that, preferably, the insertion portion  27   a  of the distal connection portion  27  is inserted into the communicating enlarged-diameter portion  43   c  such that the distal end of the loading lumen  22  is adjacent to the communication distal portion  43   b  in the connected state. 
     Since the insertion portion  27   a  is inserted into the communicating enlarged-diameter portion  43   c  such that the distal end of the loading lumen  22  is adjacent to the communication distal portion  43   b,  the embolic device  10  pushed out from the embolic device loading catheter  20  to the delivery catheter  40  is prevented from being damaged by abutting against the inner wall surface of the sheath hub  43  or from being erroneously inserted into other spaces within the sheath hub  43 . 
     In the delivery system  200  according to the present embodiment, preferably, the catheter body  21  of the embolic device loading catheter  20  may be configured to have rigidity higher than that of the sheath  41  of the delivery catheter  40 . 
     In the delivery system  200 , since the embolic device loading catheter  20  is not used by being inserted into a sheath of the delivery catheter  40  as in the direct insertion method, the embolic device loading catheter  20  does not require flexibility to follow the bent shape of the body lumen during insertion, and the rigidity of the catheter body  21  can be made higher than that of the sheath  41 . Therefore, the embolic device  10  is prevented from being damaged during packaging or unpacking. 
     The embolic device delivery medical system  300  according to the present embodiment includes: the delivery system  200 ; and the elongated insertion assisting member  50  to be assembled into the sheath lumen  42  of the delivery catheter  40  in order to assist delivery of the delivery catheter  40  into the aneurysm. The insertion assisting member  50  includes the guide wire lumen  52  that penetrates from a distal end to a proximal end and has a diameter smaller than that of the sheath lumen  42  of the delivery catheter  40 . 
     With such a configuration, when the delivery catheter  40  is to be inserted into the body lumen, since the insertion assisting member  50  is assembled, the delivery catheter  40  can be inserted into the body lumen relatively smoothly. 
     The detailed description above describes embodiments of a medical instrument set, a delivery system, and an embolic device delivery medical system. The invention is not limited, however, to the precise embodiments and variations described. Various changes, modifications and equivalents may occur to one skilled in the art without departing from the spirit and scope of the invention as defined in the accompanying claims. It is expressly intended that all such changes, modifications and equivalents which fall within the scope of the claims are embraced by the claims.