Patent Publication Number: US-2015066132-A1

Title: Balloon catheter and stent delivery system

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
     This application is a continuation of International Application No. PCT/JP2013/052845 filed on Feb. 7, 2013, and claims priority to Japanese Application No. 2012-057448 filed on Mar. 14, 2012, the entire content of both of which is incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a balloon catheter and a stent delivery system, and more specifically, to a balloon catheter and a stent delivery system used for treating a stenosed part or an occluded part occurring inside a living body lumen. 
     BACKGROUND DISCUSSION 
     A balloon catheter is a medical device used for widening a lesion when the lesion such as a stenosed part or an occluded part occurs inside a living body lumen such as a blood vessel, a bile duct, the trachea, the esophagus, and the urethra. For example, for the medical treatment of myocardial infarction, angina pectoris, and the like which are caused due to an occurrence of a stenosed part in a coronary artery, for example, a method of widening the stenosed part from the inside of the stenosed part by using a balloon catheter is adopted. 
     This type of a balloon catheter generally has a structure in which a balloon is arranged in an outer peripheral portion on a distal end side of an elongated shaft body. After the shaft body is inserted into the living body lumen until the balloon is positioned in a lesion, the balloon is dilated in a radial direction to widen the lesion by supplying a dilation fluid into the balloon through the inside of the shaft body. 
     JP-A-2008-86463 discloses a balloon catheter in which a balloon  3  is attached to the shaft body having a dual-tube structure including an outer tube  1  and an inner tube  2 , and which is illustrated in  FIG. 8  of the present disclosure. 
     As shown in  FIG. 8 , the inner tube  2  has a forward extension portion  2   a  extending forward beyond a distal end opening portion  1   a  of the outer tube  1 . A distal end portion  3   a  of the balloon  3  can be bonded to an outer periphery of the forward extension portion  2   a  of the inner tube  2  and a proximal end (“rear end”) portion  3   b  can be bonded to an outer periphery of the outer tube  1 , thereby forming a dilation chamber  4  inside the balloon  3 . The balloon  3  can be dilated by supplying a dilation fluid F to the dilation chamber  4  via a balloon dilation lumen  5 , which can be formed between the outer tube  1  and the inner tube  2 . 
     A balloon having a size in accordance with the part to be applied, the lesion, or the like is used as a balloon  3 . However, generally, the maximum dilation pressure, which is the upper limit value of a dilation pressure that can be safely used, is set in advance in a balloon. The outer diameter of the balloon  3  during dilation can be adjusted by changing an injection pressure of a dilation fluid F, which is supplied to a dilation chamber  4  within a range not exceeding the maximum dilation pressure. For example, when the injection pressure of the dilation fluid F is increased, a dilation outer diameter of the balloon  3  can be widened as indicated by the two-dot chain line in  FIG. 8 . In this manner, the balloon  3  can be dilated until the target outer diameter is acquired while confirming the injection pressure of the dilation fluid F, and thus, the lesion is widened. 
     However, when the dilation outer diameter of the balloon  3  is widened by increasing the injection pressure of the dilation fluid F, the balloon  3  is also stretched in an axial direction together with an inner tube  2  causing a stretch E occurring between a distal end portion  3   a  and a proximal end portion  3   b  of the balloon  3 . Thus, there is a possibility that the balloon  3  may also impose a burden to normal living body lumens other than the lesion. 
     The present disclosure provides a balloon catheter and a stent delivery system in which a stretch occurring between a distal end portion and a proximal end portion of a balloon can be relatively suppressed during dilation of the balloon. 
     SUMMARY 
     In accordance with an exemplary embodiment, a balloon catheter is disclosed, which includes an elongated shaft body, a dilatable balloon in which a distal end portion and a proximal end portion form a dilation chamber inside of the dilatable balloon by being away from each other and being individually bonded to an outer periphery of the shaft body, and a stretch regulation member that connects the outer periphery of the shaft body or an inner periphery of the balloon in the vicinity of the distal end portion of the balloon and the outer periphery of the shaft body or the inner periphery of the balloon in the vicinity of the proximal end portion of the balloon with each other inside the dilation chamber while regulating a stretch occurring between the distal end portion and the proximal end portion of the balloon during dilation of the balloon. 
     In accordance with an exemplary embodiment, the shaft body can include an outer tube which has a distal end opening portion and an inner tube which is inserted into the outer tube to form a balloon dilation lumen between itself and an inner peripheral surface of the outer tube and has a forward extension portion extending forward beyond the distal end opening portion of the outer tube. The distal end portion of the balloon preferably forms a distal end side bonding portion by being bonded to an outer periphery of the forward extension portion of the inner tube. The proximal end portion of the balloon preferably forms a proximal end side bonding portion by being bonded to an outer periphery of the outer tube. The dilation chamber preferably communicates with the balloon dilation lumen. 
     In accordance with an exemplary embodiment, the stretch regulation member can be formed with a plurality of filaments which respectively extend between the distal end side bonding portion and the proximal end side bonding portion and are arranged in a circumferential direction of the shaft body at equal intervals. 
     The filaments can be formed of metallic materials or stretch-resistant resin materials. 
     In accordance with an exemplary embodiment, the stretch regulation members can be configured to include three filaments. 
     In accordance with an exemplary embodiment, a stent delivery system according to the present disclosure includes the balloon catheter disclosed above, and a stent that is arranged in an outer periphery of a balloon of the balloon catheter and expands in accordance with dilation of the balloon. 
     In accordance with an exemplary embodiment of the present disclosure, a stretch regulation member can connect an outer periphery of a shaft body or an inner periphery of a balloon in the vicinity of a distal end portion of the balloon and the outer periphery of the shaft body or the inner periphery of the balloon in the vicinity of a proximal end portion of the balloon with each other, and thus, a stretch occurring between the distal end portion and the proximal end portion of the balloon during dilation of the balloon can be relatively suppressed. 
     In accordance with an exemplary embodiment, a balloon catheter is disclosed comprising: an elongated shaft body, the shaft body including an outer tube which has a distal end opening portion, and an inner tube which is inserted into the outer tube to form a balloon dilation lumen between the inner tube and an inner peripheral surface of the outer tube and has a forward extension portion extending forward beyond the distal end opening portion of the outer tube; a dilatable balloon in which a distal end portion and a proximal end portion form a dilation chamber inside of the dilatable balloon by being away from each other and being individually bonded to an outer periphery of the shaft body; and a plurality of filaments that connect the outer periphery of the shaft body or an inner periphery of the balloon of the distal end portion of the balloon and the outer periphery of the shaft body or an inner periphery of the balloon of the proximal end portion of the balloon with each other inside the dilation chamber while regulating a stretch occurring between the distal end portion and the proximal end portion of the balloon during dilation of the balloon. 
     In accordance with an exemplary embodiment, a method is disclosed of regulating a stretch occurring between a distal end portion and a proximal end portion of a dilatable balloon during dilation, comprising: placing a stretch regulation member that connects an outer periphery of an elongated shaft body or an inner periphery of the balloon of the distal end portion of the balloon and an outer periphery of the elongated shaft body or an inner periphery of the balloon of the proximal end portion of the balloon with each other inside a dilation chamber of the dilatable balloon. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a side view illustrating an overall structure of a balloon catheter according to an exemplary embodiment of the disclosure. 
         FIG. 2  is a cross-sectional view illustrating a structure of a balloon in the balloon catheter in accordance with the exemplary embodiment as shown in  FIG. 1 . 
         FIG. 3  is a cross-sectional view taken along line A-A of  FIG. 2 . 
         FIG. 4  is a perspective view illustrating a structure inside the balloon in the balloon catheter in accordance with the exemplary embodiment as shown in  FIG. 1 . 
         FIG. 5  is a cross-sectional view illustrating a structure of the balloon in a balloon catheter in accordance with an exemplary embodiment of the disclosure. 
         FIG. 6  is a cross-sectional view illustrating a structure of the balloon in a balloon catheter in accordance with an exemplary embodiment of the disclosure. 
         FIG. 7  is a side view illustrating an overall structure of an exemplary stent delivery system of the disclosure. 
         FIG. 8  is a cross-sectional view illustrating a structure of the balloon in the balloon catheter in the related art. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates an overall structure of a balloon catheter according to an exemplary embodiment. The balloon catheter can include an elongated shaft body  11 . A dilatable balloon  12  is arranged to an outer peripheral portion of the distal end portion of the shaft body  11 . A branch hub  13  is attached to a proximal end portion of the shaft body  11 . The shaft body  11  and the balloon  12  are inserted into a living body lumen such as a blood vessel, a bile duct, the trachea, the esophagus and the urethra when treating a lesion. A guide wire  14  is inserted through the inside of the shaft body  11  to be able to move backward and forward. The branch hub  13  has an operation port  15  for making the guide wire  14  which is inserted through the inside of the shaft body  11  move backward and forward, and a fluid port  16  for injecting and suctioning a dilation fluid with respect to the balloon  12  via the inside of the shaft body  11 . 
     As illustrated in  FIG. 2 , the shaft body  11  has a dual-tube structure including an outer tube  17  and an inner tube  18 , which is inserted into the outer tube  17 . A balloon dilation lumen  19  is formed between an outer peripheral surface of the inner tube  18  and an inner peripheral surface of the outer tube  17 . 
     The balloon  12  has a middle portion  12   c  which is provided in the middle of the balloon  12  and of which an outer diameter is substantially uniform. The balloon  12  has a distal end portion  12   a  which is provided closer to a distal end side than the middle portion  12   c  and of which an outer diameter is smaller than that of the middle portion  12   c , and a proximal end portion (“rear end portion”)  12   b  which is provided closer to a proximal or rear end side than the middle portion  12   c  and of which an outer diameter is smaller than that of the middle portion  12   c . The balloon  12  also includes a distal end side tapered portion  12   d  which is provided between the distal end portion  12   a  and the middle portion  12   c , and a proximal end side tapered portion (‘rear end side tapered portion”)  12   e  which is provided between the proximal end portion  12   b  and the middle portion  12   c.    
     The outer tube  17  has a distal end opening portion  20 , and the inner tube  18  has a forward extension portion  18   a  extending closer to the distal end side than the distal end opening portion  20  of the outer tube  17 , that is, further forward of distal end opening portion  20  of the outer tube  17 . A distal end side bonding portion  21  is formed by bonding the distal end portion  12   a  of the balloon  12  to an outer periphery of the forward extension portion  18   a  of the inner tube  18 , and a proximal end side bonding portion (“rear end side bonding portion”)  22  is formed by bonding the proximal end portion  12   b  of the balloon  12  to an outer periphery of the distal end of the outer tube  17 . Accordingly, a dilation chamber  23  communicating with the balloon dilation lumen  19  can be formed inside the balloon  12 . 
     Inside the dilation chamber  23  of the balloon  12 , the balloon  12  can include three filaments  24  extending between the distal end side bonding portion  21  and the proximal end side bonding portion  22 . The three filaments  24  can be respectively fixed between the outer periphery of the inner tube  18  (forward extension portion  18   a ) and the inner periphery of the balloon  12  (distal end portion  12   a ) in the distal end side bonding portion  21 , and between the outer periphery of the outer tube  17  and the inner periphery of the balloon  12  (proximal end portion  12   b ) in the proximal end side bonding portion  22 . In accordance with an exemplary embodiment, the three filaments  24  connect the distal end side bonding portion  21  and the proximal end side bonding portion  22  with each other and function as stretch regulation members regulating a stretch occurring between the distal end portion  12   a  and the proximal end portion  12   b  of the balloon  12  during dilation of the balloon  12 . In accordance with an exemplary embodiment, the filaments  24  can be arranged in a circumferential direction of the forward extension portion  18   a  of the inner tube  18  at equal intervals, as illustrated in  FIG. 3 . 
     Inside the dilation chamber  23  of the balloon  12  and on the outer periphery of the forward extension portion  18   a  of the inner tube  18 , contrast markers  25  can be respectively arranged in the vicinity of the distal end portion  12   a  and the proximal end portion  12   b  of the balloon  12 . In accordance with an exemplary embodiment, on account of these contrast markers  25 , a position of the balloon  12  which is inserted into a living body lumen can be confirmed from the outside of a living body through an X-ray contrast. 
     The Inside of the inner tube  18  of the shaft body  11  communicates with the operation port  15  of the branch hub  13 , and the guide wire  14  is inserted through the overall length of the inner tube  18  and the operation port  15 . 
     The balloon dilation lumen  19  formed between the outer tube  17  and the inner tube  18  of the shaft body  11  communicates with the fluid port  16  of the branch hub  13  so that the dilation fluid can be injected to the inside of the dilation chamber  23  of the balloon  12  from the fluid port  16  via the balloon dilation lumen  19 . In this case, the distal end side bonding portion  21  which is positioned on the outer periphery of the forward extension portion  18   a  of the inner tube  18  and the proximal end side bonding portion  22  which is positioned on the outer periphery in the vicinity of the distal end of the outer tube  17  are connected with each other by the filaments  24 . As illustrated in  FIG. 4 , since a large gap can be formed between the filaments  24  adjacent to each other, the dilation fluid can be injected into the dilation chamber  23  of the balloon  12  from the balloon dilation lumen  19  through the distal end opening portion  20  of the outer tube  17  or can be suctioned from the dilation chamber  23  through the distal end opening portion  20  of the outer tube  17 , without being disturbed by the filaments  24 . 
     In accordance with an exemplary embodiment, for example, it can be preferable to use a material having certain flexibility as a material forming the outer tube  17  and the inner tube  18  of the shaft body  11 . For example, the outer tube  17  and the inner tube  18  of the shaft body  11  can be a resin material such as polyolefin such as polyethylene, polypropylene, an ethylene-propylene copolymer and an ethylene-vinyl acetate copolymer, polyvinyl chloride, polyurethane, polyamide, a polyamide elastomer, polyimide, a silicon resin, polyether ether ketone, polyester, a polyester elastomer, and the like. 
     In accordance with an exemplary embodiment, for example, it can be preferable to form the balloon  12  with a high strength polymer, which can be stretchable. For example, the balloon  12  can be a resin material such as polyethylene terephthalate, polyester in which a main acid component or a main glycol component of polyethylene terephthalate is changed, a polyester elastomer, polyamide (nylon 12, nylon 11, MXD 6 nylon, and the like), a polyamide elastomer, polyarylene sulfide such as PPS (polyphenylene sulfide). 
     In accordance with an exemplary embodiment, for example, it can be preferable to form the filaments  24  used as the stretch regulation member with a material which has certain flexibility so as not to lessen softness in a portion corresponding to the balloon  12  while being unlikely to stretch against a tension force acting during dilation of the balloon  12 . As a constituent material of the filament  24 , for example, a metallic material or a stretch-resistant resin material can be used. 
     In accordance with an exemplary embodiment, since a metallic material generally has a greater Young&#39;s modulus than a resin material constituting the inner tube  18  and the balloon  12 , the filament  24  is unlikely to stretch even though the filament  24  is formed to have a small diameter, thereby being suitable to be used as a constituent material of the filament  24 . As a metallic material, for example, stainless steel such as SUS 304, SUS 316L can be used. 
     A stretch occurring between the distal end portion  12   a  and the proximal end portion  12   b  of the balloon  12  can be relatively suppressed when forming the filament  24  with a stretch-resistant resin material. In accordance with an exemplary embodiment, for example, it can also be effective when a fiber-reinforced resin, which is reinforced by a glass fiber, carbon fiber, and the like is used. 
     The contrast marker  25  can be formed of a material, which can be relatively easily, confirmed through an X-ray contrast, for example, gold, platinum, iridium, tungsten, an alloy of gold, platinum, iridium or tungsten, or a silver-palladium alloy. 
     When manufacturing a balloon catheter, the distal end portions of three filaments  24  can be in states of being respectively inserted between an inner peripheral surface of the distal end portion  12   a  of the balloon  12  and an outer peripheral surface of the forward extension portion  18   a  of the inner tube  18 , and then, the inner peripheral surface of the distal end portion  12   a  of the balloon  12  can be fused on the outer peripheral surface of the forward extension portion  18   a  of the inner tube  18 . Therefore, in accordance with an exemplary embodiment, the distal end side bonding portion  21  can be formed and each distal end portion of the filaments  24  can be fixed to the distal end side bonding portion  21  at the same time. Similarly, the proximal end portions (“rear end portions”) of three filaments  24  can be in states of being respectively inserted between an inner peripheral surface of the proximal end portion  12   b  of the balloon  12  and an outer peripheral surface in the vicinity of the distal end of the outer tube  17 , and then, the inner peripheral surface of the proximal end portion  12   b  of the balloon  12  can be fused on the outer peripheral surface of the outer tube  17 . Therefore, in accordance with an exemplary embodiment, the proximal end side bonding portion  22  can be formed and each proximal end portion of the filaments  24  can be fixed to the proximal end side bonding portion  22  at the same time. 
     In accordance an exemplary embodiment, operations of the exemplary embodiments as shown in  FIGS. 1-4  are disclosed. 
     In accordance with an exemplary embodiment, initially, the guide wire  14  inserted into the inner tube  18  of the shaft body  11  from the operation port  15  is caused to protrude forward beyond the distal end portion of the inner tube  18 , and the guide wire  14  serves as a leading guide for the balloon catheter to be inserted into the living body lumen such as a blood vessel. In this case, the dilation fluid is not yet injected into the dilation chamber  23  of the balloon  12  and the balloon  12  is in a folded state. An X-ray contrast is performed to recognize the contrast marker  25  arranged inside the dilation chamber  23  of the balloon  12  to confirm a position of the balloon  12  inside a living body lumen. 
     An insertion operation of the balloon catheter is completed, once the positioning of the balloon  12  is confirmed in the lesion requiring treatment. Here, the dilation fluid can be injected into the dilation chamber  23  of the balloon  12  through the balloon dilation lumen  19  from the fluid port  16 . The balloon  12  can then be dilated until the target outer diameter is acquired while confirming the injection pressure of the dilation fluid. Accordingly, the lesion such as a stenosed part or an occluded part can be widened. 
     In this case, a tension force acts in the balloon  12  and the inner tube  18  along the axial direction in accordance with the injection pressure of the dilation fluid. However, since the distal end side bonding portion  21  which is positioned on the outer periphery of the forward extension portion  18   a  of the inner tube  18  and the proximal end side bonding portion  22  which is positioned on the outer periphery in the vicinity of the distal end of the outer tube  17  are connected with each other by three filaments  24 , a stretch occurring between the distal end portion  12   a  and the proximal end portion  12   b  of the balloon  12  is regulated by the filaments  24 . Accordingly, the balloon  12  can be relatively suppressed from being stretched in the axial direction. 
     For example, in this manner, it is possible to help prevent dilation of the balloon  12  in advance such that the balloon  12  does not impose a burden to normal living body lumens other than the lesion while dilating a lesion such as a stenosed part and an occluded part. 
     When the treatment of the lesion ends, the balloon  12  is folded by suctioning the dilation fluid from the inside of the dilation chamber  23  of the balloon  12  via the balloon dilation lumen  19 , and then, in this state, the balloon catheter is drawn out from the inside of the living body lumen. 
     In accordance with an exemplary embodiment, the number of filaments  24  used as the stretch regulation member is not limited to three. For example, as long as the filament can regulate a stretch without lessening the softness of the balloon catheter in a portion corresponding to the balloon  12 , it is possible to adopt equal to or less than two, or equal to or more than four filaments  24 . 
     In accordance with an exemplary embodiment, in place of the filament  24 , a member having a rod shape or a plate shape may be used as the stretch regulation member. However, in this case, it can be desirable not to lessen the softness of the balloon catheter in a portion corresponding to the balloon  12 . 
     In the exemplary embodiment disclosed above, although both the end portions of each filament  24  are respectively fixed to the distal end side bonding portion  21  and the proximal end side bonding portion  22  of the balloon  12 , it is not limited thereto. For example, as illustrated in  FIG. 5 , the distal end portion of each filament  24  can be fixed to be closer to a proximal end side than the distal end portion  12   a  (distal end side bonding portion  21 ) of the balloon  12 , and specifically fixed to the outer periphery of the forward extension portion  18   a  of the inner tube  18  in a position P1 in the distal end side tapered portion  12   d . The proximal end portion of each filament  24  can be fixed to be closer to the distal end side than the proximal end portion  12   b  (proximal end side bonding portion  22 ) of the balloon  12 , and specifically fixed to the outer periphery of the outer tube  17  in a position P2 in the proximal end side tapered portion  12   e.    
     In accordance with an exemplary embodiment, in this manner, even if the positions P1 and P2 of both the end portions of each filament  24  are slightly deviated from the distal end portion  12   a  and the proximal end portion  12   b  of the balloon  12 , when the outer periphery of the forward extension portion  18   a  of the inner tube  18  in the vicinity (specifically, distal end side tapered portion  12   d ) of the distal end portion  12   a  of the balloon  12  and the outer periphery of the outer tube  17  in the vicinity (specifically, proximal end side tapered portion  12   e ) of the proximal end portion  12   b  of the balloon  12  are connected by each of the filaments  24 , a stretch occurring between the position P1 and the position P2 can be relatively suppressed on account of an existence of the filaments  24  during dilation of the balloon  12 , and thus, a certain degree of the stretch occurring between the distal end portion  12   a  and the proximal end portion  12   b  of the balloon  12  can be regulated. 
     In accordance with an exemplary embodiment, as shown in  FIG. 5 , the distal end portion of each of the filaments  24  may be fixed to the distal end side bonding portion  21 , and the proximal end portion of each of the filaments  24  may be fixed to the outer periphery of the outer tube  17  in the position P2, or the distal end portion of each of the filaments  24  may be fixed on the outer periphery of the forward extension portion  18   a  of the inner tube  18  in the position P1, and the proximal end portion of each of the filaments  24  may be fixed to the proximal end side bonding portion  22 . 
     As illustrated in  FIG. 6 , the distal end portion of each of the filaments  24  can be fixed to the inner periphery of the balloon  12  closer to the proximal end side than the distal end portion  12   a  (distal end side bonding portion  21 ) of the balloon  12 , and specifically fixed to the inner periphery (position P3) of the distal end side tapered portion  12   d , and the proximal end portion of each of the filaments  24  can be fixed to the inner periphery of the balloon closer to the distal end side than the proximal end portion  12   b  (proximal end side bonding portion  22 ) of the balloon  12 , and specifically fixed to the inner periphery (position P4) of the proximal end side tapered portion  12   e.    
     In this manner, for example, even though the positions P3 and P4 of both the end portions of each of the filaments  24  are slightly deviated from the distal end portion  12   a  and the proximal end portion  12   b  of the balloon  12 , when the inner periphery of the balloon  12  in the vicinity (specifically, distal end side tapered portion  12   d ) of the distal end portion  12   a  of the balloon  12  and the inner periphery of the balloon  12  in the vicinity (specifically, proximal end side tapered portion  12   e ) of the proximal end portion  12   b  of the balloon  12  are connected by each of the filaments  24 , a stretch occurring between the position P3 and the position P4 can be relatively suppressed on account of an existence of the filaments  24  during dilation of the balloon  12 , and thus, a certain degree of the stretch occurring between the distal end portion  12   a  and the proximal end portion  12   b  of the balloon  12  can be regulated. 
     In accordance with an exemplary embodiment, as shown in  FIG. 6 , the distal end portion of each of the filaments  24  may be fixed to the distal end side bonding portion  21 , the proximal end portion of each of the filaments  24  may be fixed to the inner periphery of the balloon  12  in the position P4, or the distal end portion of each of the filaments  24  may be fixed on the inner periphery of the balloon  12  in the position P3, and the proximal end portion of each of the filaments  24  may be fixed to the proximal end side bonding portion  22 . 
     In the exemplary embodiment as disclosed, the description is given regarding a so-called over-the-wire-type balloon catheter in which the guide wire  14  is inserted through from the proximal end portion having the branch hub  13  attached thereto to the distal end portion, the disclosure can be similarly applied to a so-called rapid-exchange-type balloon catheter in which the guide wire is inserted through only the distal end portion. 
     As illustrated in  FIG. 7 , a stent  26 , which expands in accordance with dilation of the balloon  12 , may be arranged on the outer periphery of the balloon  12  of the balloon catheter according to the exemplary embodiments disclosed above in a stent delivery system. 
     The detailed description above describes a balloon catheter and a stent delivery system. The disclosure is not limited, however, to the precise embodiments and variations described. Various changes, modifications and equivalents can effected by one skilled in the art without departing from the spirit and scope of the disclosure 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.