Patent Publication Number: US-2020297943-A1

Title: System for temperature-maintaining and injecting contrast medium for microcatheter and system for temperature-maintaining and injecting therapeutic suspension medicine for microcatheter

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is the National Stage of International Application No. PCT/JP2017/010026, having an International Filing Date of 13 Mar. 2017, which designated the United States of America, and which International Application was published under PCT Article 21 (2) as WO Publication No. 2017/169698 A1, and which claims priority from and the benefit of Japanese Application No. 2016-083200, filed on 1 Apr. 2016, the disclosures of which are incorporated herein by reference in their entireties. 
    
    
     1. FIELD 
     The presently disclosed embodiment relates to a system for temperature-maintaining and injecting contrast medium for a microcatheter and a system for temperature-maintaining and injecting therapeutic suspension medicine for a microcatheter. 
     2. DESCRIPTION OF RELATED DEVELOPMENTS 
     So far a medical practice for moving a catheter percutaneously inserted in a blood vessel to brain, heart or internal organs such as abdominal region for administering and injection of a therapeutic agent, an embolic substance, a contrast medium or the like thereinto has been performed. Recently with advances in medicine, injection of a therapeutic agent, an embolic substance, a contrast medium or the like into a thinner peripheral blood vessel became necessary, and research and development relating to enhancement of functionality of a microcatheter that can be inserted into such a thin peripheral blood vessel are continued enthusiastically. 
     In the research and development on a microcatheter, various requirements for operability of the microcatheter are demanded since it is necessary for an operator to advance the microcatheter surely along the tortuous and thinner peripheral blood vessel. Such requirements for functionality include pushability for surely transmitting a pushing force from an operator to a tip of the microcatheter, torque transmission property for surely transmitting a turning force applied by an operator to a tip of the microcatheter, followability to a guide wire for advancing in a winding blood vessel along the guide wire passing through an inner cavity of the catheter, and kink resistance of the microcatheter causing no bending even at a bent portion or a curved portion of a blood vessel. In order to achieve such operability, configuration for providing a reinforcing layer having a braided structure or a coil structure is employed on many microcatheters. 
     SUMMARY 
     The diameter of an inner cavity of a microcatheter becomes thinner, and in addition, its effective length becomes longer (for example, an effective length becomes longer from 125 cm to 150 cm), resulting in further burden being imposed on injection. Under such a situation, for example, in either of a case of a contrast examination for imaging of a site to be treated or a case of treatment of embolus of the affected part defined by a contrast examination, there arises a problem with high viscosity injection (i.e. a high injection pressure is required) when injecting a contrast medium or a therapeutic suspension medicine for embolus. 
     In the contrast examination, for example in case of injection of a contrast medium by pushing a syringe by hand, an injection pressure and rate of a contrast medium cannot be maintained constant, and in case of injection of a contrast medium by means of a usual high pressure injector (100 to 150 cc of a syringe size), an accuracy of injection cannot be kept constant. Further, in injection of a therapeutic suspension for embolus including an anticancer drug, injection becomes difficult due to a viscosity of the suspension and a smaller diameter of a microcatheter. 
     However, in a contrast examination, trials for solving the above-mentioned problems and assisting the solution of the problems has been hardly made, and only a method of enabling an injection amount to be increased to some extent by reduction of a contrast medium viscosity by heating and matching for optimum concentration of a contrast medium is disclosed in “Study on Optimum Iodine Concentration of Contrast Medium used on Microcatheter” Magazine of Tohoku Sectional Meeting of Japanese Society of Radiological Technology, No. 13, January 2004, 41 st  Tohoku Sectional Annual Meeting Publication, Page 64. recently opened to the public. Similarly, also for treatment of embolus, trials for solving the above-mentioned problem has hardly been made so far, and only heating of a mixing vessel containing an anticancer drug and a contrast medium in a water bath as disclosed in Kora Shinichi et al., Journal of New Remedies and Clinics Vol. 61, No. 5, pp. 76-82, 2012 has been employed. 
     Therefore, an object of the disclosed embodiment is to provide a system for temperature-maintaining and injecting a contrast medium for a microcatheter and a system for temperature-maintaining and injecting a therapeutic suspension medicine for a microcatheter which allow an injection pressure of a contrast medium and a therapeutic suspension medicine for embolus to be reduced and make easy injection of a contrast medium and a therapeutic suspension medicine for embolus. 
     The system for temperature-maintaining and injecting a contrast medium for a microcatheter comprises an injector for injecting the contrast medium and a pump control device connected to the injector, wherein the injector for injecting the contrast medium comprises a pump head portion and a small diameter syringe connected to the pump head portion, wherein the system for temperature-maintaining and injecting the contrast medium further comprises an outer peripheral temperature-maintaining heater unit to be attached on an outer periphery of the small diameter syringe, and wherein the outer peripheral temperature-maintaining heater unit to be attached on the outer periphery of the small diameter syringe is connected to a heat source output terminal provided on the pump head portion. 
     The system for temperature-maintaining and injecting a therapeutic suspension medicine for a microcatheter comprises a microcatheter, a syringe for manual operation for containing a suspension including an anticancer drug and a contrast medium for treatment of embolus, and a connecting portion for connecting the syringe for manual operation and the microcatheter, wherein the system for temperature-maintaining and injecting a therapeutic suspension medicine further comprises an outer peripheral temperature-maintaining heater unit being mounted on an outer periphery of the syringe for manual operation. 
     The system for temperature-maintaining and injecting a contrast medium for a microcatheter and the system for temperature-maintaining and injecting a therapeutic suspension medicine for a microcatheter of the disclosed embodiment are capable of reducing viscosities of a contrast medium and a therapeutic suspension medicine for embolus (reducing an injection pressure) and making the injection easy. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram schematically showing a system for temperature-maintaining and injecting a contrast medium for a microcatheter according to one aspect of the disclosed embodiment. 
         FIG. 2  is a view showing a combined state of a pump head portion and a small diameter syringe to be used on the system for temperature-maintaining and injecting the contrast medium of  FIG. 1 . 
         FIG. 3(A)  is a view showing a connected state of a long plunger being connected to a small diameter syringe, and  FIG. 3(B)  is a view showing a separated state of the long plunger being separated from the small diameter syringe. 
         FIG. 4  is a schematic view showing an outer peripheral temperature-maintaining heater unit being mounted on a small diameter syringe and a contrast medium bottle. 
         FIG. 5(A)  is a reference drawing showing a non-separable plunger being connected to the pump head portion, and  FIG. 5(B)  is a view showing a connected state where a plunger from which the long plunger is detached is connected to the pump head portion in one aspect of the disclosed embodiment. 
         FIG. 6(A)  is a reference drawing showing a fixed state of pump head portion of a general contrast medium injector being fixed to a catheter operating table, and  FIG. 6(B)  is a view showing an attached state of pump head portion being mounted on an arm stand in one aspect of the disclosed embodiment. 
         FIG. 7(A)  is a view showing a pump head portion having a built-in drive unit according to one aspect of the disclosed embodiment, and  FIG. 7(B)  is a view showing a pump head portion to which an external drive unit can be mounted according to another aspect of the disclosed embodiment, wherein the drive unit is not built in the pump head portion. 
         FIG. 8  is a graph showing a comparison of an effect in use of a film heater for a contrast medium bottle and non-use thereof in a temperature maintaining experiment. 
         FIG. 9  is a view showing an example of a hand switch portion. 
         FIG. 10  is a schematic view showing the system for temperature-maintaining and injecting therapeutic suspension medicine according to one aspect of the disclosed embodiment. 
         FIG. 11  is a view showing a state where an outer peripheral temperature-maintaining heater unit for a small diameter syringe and an outer peripheral temperature-maintaining heater unit for a syringe for manual operation are connected to the pump head portion. 
         FIG. 12  is a view showing a film heater for a small diameter syringe or a syringe for manual operation. 
         FIG. 13  is a view showing a film heater for a contrast medium bottle. 
     
    
    
     DETAILED DESCRIPTION 
     First Aspect 
     By referring to the attached drawings, an aspect of a system for temperature-maintaining and injecting a contrast medium for a microcatheter of the disclosed embodiment is described below. It is noted that the following aspect is only an example, and the system for temperature-maintaining and injecting the contrast medium of the disclosed embodiment is not limited to the following aspect. 
     As shown in a block diagram of  FIG. 1 , the system for temperature-maintaining and injecting contrast medium (hereinafter simply referred to as an injecting system)  100  has a movable pump head portion  10   a . The movable pump head portion  10   a  is arranged on an injection site of a patient, and injection of a contrast medium is initiated by means of any of a hand switch portion  10   b  and a foot switch portion  10   i  provided at an operating field or a hand switch portion  10   g  provided in an operation room according to an injection rate and amount to be set by an injection control section  10   f  (pump control device). 
     The injecting system  100  according to one aspect of the disclosed embodiment is described below in detail using  FIGS. 1 to 9 . 
     [ FIG. 1  is a block diagram schematically showing the injecting system according to one aspect of the disclosed embodiment, and  FIG. 2  is a view showing a combined state of a pump head portion and a small diameter syringe to be used on the injecting system of  FIG. 1 . 
     In  FIG. 1 , a reference symbol  100  represents the whole configuration of the injecting system,  10   f  represents an injection control section (pump control device),  10   b  and  10   i  represent a hand switch portion and a foot switch portion, respectively provided at an operating field,  10   g  represents a hand switch portion provided in an operation room,  10   a  represents a movable pump head portion, and  30  represents a small diameter syringe to be mounted on the pump head portion  10   a . Further, a reference symbol  10   k  represents a main unit as a main power source,  10   h  represents a relay box disposed between the main unit  10   k  and the pump head portion  10   a ,  10   e  represents a motor box disposed between the relay box  10   h  and the pump head portion  10   a ,  10   c  represents an outer peripheral temperature-maintaining heater unit for a small diameter syringe,  10   d  represents an outer peripheral temperature-maintaining heater unit of a syringe for manual operation, and  10   j  represents a monitor provided for an operator. Reference symbols  10   l ,  10   m ,  10   n  and  10   o  are cables for power supply or cables for signal transmission connecting the above-mentioned components. 
       FIG. 2  is a view showing a combined state of the pump head portion and the small diameter syringe to be used on the injecting system of  FIG. 1 . In  FIG. 2 , a reference symbol  20   a  represents a syringe mounting portion,  20   b  represents a plunger connecting portion,  20   c  represents a heat source output terminal,  20   d  represents a housing,  80   b  represents a wing portion for fixing a microcatheter to a syringe, and  80   a  represents a microcatheter. 
       FIG. 3(A)  is a view showing a connected state of a long plunger being connected to a small diameter syringe, and  FIG. 3(B)  is a view showing a separated state of the long plunger being separated from the small diameter syringe. In  FIG. 3 , a reference symbol  30   a  represents a separable long plunger,  30   c  represents a short plunger to be connected to a gasket of the short syringe  30 , and  30   b  represents a long plunger connecting portion for connecting the long plunger  30   a  to the short plunger  30   c .  FIG. 3(A)  shows that the separable long plunger  30   a  is connected to the small diameter syringe  30  by connecting the long plunger  30   a  to the short plunger  30   c  with the long plunger connecting portion  30   b . Further,  FIG. 3(B)  shows that the separable long plunger  30   a  is separated from the short plunger  30   c  of the small diameter syringe  30  and the small diameter syringe  30  has only the short plunger  30   c.    
       FIG. 4  is a schematic view showing an outer peripheral temperature-maintaining heater unit being mounted on a small diameter syringe and a contrast medium bottle.  10   c  represents the outer peripheral temperature-maintaining heater unit for a small diameter syringe,  10   d  represents the outer peripheral temperature-maintaining heater unit for the contrast medium bottle.  10   c   2  and  10   d   2  represent power cords for heat source to the outer peripheral temperature-maintaining heater units  10   c ,  10   d , respectively. Further a reference symbol  70  represents the contrast medium bottle, and  70   a  represents a contrast medium filling line. 
       FIG. 5(A)  is a reference drawing showing a non-separable plunger being connected to the pump head portion, and  FIG. 5(B)  is a view showing a connected state where a plunger from which the long plunger is detached is connected to the pump head portion in one aspect of the disclosed embodiment. In  FIG. 5(A) , a reference symbol  40  represents a plunger to be used on a general non-separable syringe. 
       FIG. 6(A)  is a reference drawing showing a fixed state of a pump head portion of a general contrast medium injector being fixed to a catheter operating table, and  FIG. 6(B)  is a view showing an attached state of a pump head portion being mounted on an arm stand in one aspect of the disclosed embodiment. In  FIG. 6(A) , a reference symbol X represents a catheter operating table to be used under X-ray environment,  51  represents a fixing pole mounted on a side rail of the catheter operating table X for fixing a pump head of a general contrast medium injector, and  51   a  represents a long extended injection tube extending from the pump head mounted on the fixed pole  51  to an operating field. In  FIG. 6(B) , a reference symbol  52  represents an arm stand for attaching the pump head portion  10   a  in this aspect of the disclosed embodiment, and  52   a  represents a short extended injection tube slightly extending in a short length from the pump head  10   a  moved to the vicinity of the operating field by the arm stand  52 . 
       FIG. 7(A)  is a view showing a pump head portion having a built-in drive unit according to one aspect of the disclosed embodiment, and  FIG. 7(B)  is a view showing a pump head portion to which an external drive unit can be mounted according to another aspect of the disclosed embodiment, wherein the drive unit is not built in the pump head portion. In  FIG. 7(A)  and  FIG. 7(B) , a reference symbol  62  represents a plunger drive unit moving so as to move the plunger (the short plunger  30   c ) of the small diameter syringe  30 , and  61  represents a motor drive unit for allowing the plunger drive unit  62  to be moved by a motor. Further in  FIG. 7(B) , a reference symbol  62  represents the plunger drive unit similarly to  FIG. 7(A) , and  63  shows a part of a flexible shaft (tube) for moving the plunger drive unit  62  by transmitting power of an external motor not shown in the drawing. 
       FIG. 8  is a graph showing a comparison of an effect in use of a film heater for a contrast medium bottle and non-use thereof in a temperature maintaining experiment. In  FIG. 8 , an axis of abscissa indicates a time, and an axis of ordinate indicates a temperature (° C.). In  FIG. 8 , T 1  represents a temperature of the outer periphery of the contrast medium bottle in an elapsed time when using the outer peripheral temperature-maintaining heater unit  10   d  for a contrast medium bottle, T 2  represents a temperature of the outer periphery of the contrast medium bottle in an elapsed time when using no outer peripheral temperature-maintaining heater unit  10   d , and T 3  represents an ambient temperature. 
     As shown in  FIG. 1 , the injecting system  100  according to this aspect comprises the contrast medium injector I and the injection control section (pump control device)  10   f.    
     The injecting system  100  is used for injecting a contrast medium into a patient for catheter treatment. In this aspect, as shown in  FIG. 1 , in addition to the injector I and the injection control section  10   f , the injecting system  100  comprises the switch portions (a hand switch portion  10   b  provided at an operating field, the foot switch portion  10   i  provided at an operating field and the hand switch portion  10   g  provided in an operation room) for operation of contrast medium injection by the injector I, the main unit  10   k  as a main power source, the relay box  10   h  connected to the main unit  10   k , etc. Further, the injecting system  100  includes the catheter operating table X (see  FIG. 6 ), which is provided in an operation room, for treatment of a patient and a suspension stand (not shown) for suspending the contrast medium bottle  70  (see  FIG. 4 ). 
     The injecting system  100  injects a contrast medium into the interior of the body of a patient by operating any of the switch portions  10   b ,  10   i ,  10   g , thereby motor-driving the injector I. More specifically, a contrast medium in the small diameter syringe  30  is injected into the interior of the body of a patient through the microcatheter  80   a  (see  FIG. 2 ) connected to the injector I. The switch portions may be operated not only for injecting a contrast medium but also for filling a contrast medium into the small diameter syringe  30 . For example, as shown in  FIG. 9 , the switch portion  10   b  provided at an operating field may include an injection operation switch  51  and a filling operation switch S 2 . The injection operation switch  51  has a safety button SB, and when the safety button SB is pressed, the lever-shaped injection operation switch  51  can be operated, which can prevent an erroneous operation of the switch. When the injection operation switch  51  is operated, a predetermined amount of a contrast medium is injected at a set injection rate. When the predetermined amount of the contrast medium has been injected or when the operation of the injection operation switch  51  is stopped, the injection of the contrast medium is terminated. When the filling operation switch S 2  is operated, filling of the contrast medium into the small diameter syringe  30  is carried out automatically at a set filling rate. When the small diameter syringe  30  is fully filled with the contrast medium or when the filling operation switch S 2  is pressed again, the filling is terminated. It is noted that the above-mentioned configuration of the injecting system  100  is an example, and the configuration of the injecting system  100  is not limited to that shown in  FIG. 1 . In  FIG. 2 , while the microcatheter  80   a  is connected directly to the injector I (the small diameter syringe  30 ), the microcatheter  80   a  may be connected indirectly to the injector I via the short extended injection tube  52   a  having a necessary minimum length, or the like. 
     As shown in  FIGS. 1 and 2 , the injector I has the pump head portion  10   a  and the small diameter syringe  30  connected to the pump head portion  10   a.    
     The pump head portion  10   a  is an injector head for injecting the contrast medium into a patient by sliding the plunger of the small diameter syringe  30 . As shown in  FIG. 2 , the pump head portion  10   a  according to this aspect comprises a housing  20   d , a syringe mounting portion  20   a  provided on the housing  20   d  and to be connected to the small diameter syringe  30 , and a plunger connecting portion  20   b  to which the plunger (the short plunger  30   c ) of the small diameter syringe  30  is connected. 
     In this aspect, the syringe mounting portion  20   a  is designed as a single type holding a single small diameter syringe  30 . The structure of the syringe mounting portion  20   a  is not limited particularly as far as the small diameter syringe  30  can be mounted. For example, the syringe mounting portion  20   a  can be configured to be engaged with a flange portion of the small diameter syringe  30  to lock the syringe. The structure of the plunger connecting portion  20   b  is not limited particularly as far as the short plunger  30   c  of the small diameter syringe  30  can be connected to the pump head portion  10   a.    
     As shown in  FIG. 2  and  FIG. 4 , the pump head portion  10   a  has the heat source output terminal  20   c  to which the power cord  10   c   2  for heat source is connected in order to heat the outer peripheral temperature-maintaining heater unit  10   c . While the position where the heat source output terminal  20   c  is provided is not limited particularly, in this aspect, the heat source output terminal  20   c  is disposed on a side wall of the pump head portion  10   a  in the vicinity of the connecting part which connects the pump head portion  10   a  with the small diameter syringe. The power cord  10   c   2  for heat source has an insertion type connecting part to be inserted into the heat source output terminal  20   c . Therefore, the power cord  10   c   2  for heat source can be easily connected to the heat source output terminal  20   c  in parallel with the connection of the plunger of the small diameter syringe  30  to the plunger connecting portion  20   b . Further, by connecting the power cord  10   c   2  for heat source to the heat source output terminal  20   c  of the pump head portion  10   a , the power cord  10   c   2  for heat source will not disturb manipulation of catheter. Namely, when the pump head portion  10   a  and the catheter operating table X are moved during the treatment, the power cord  10   c   2  for heat source moves together with the pump head portion  10   a  and the catheter operating table X, and there is no need of considering an excessive length of the power cord  10   c   2  for heat source. Therefore, a situation such that the power cord  10   c   2  for heat source is located at a position disturbing manipulation of catheter treatment as a result of movement of the pump head portion  10   a  and the catheter operating table X does not arise unlike the case where the power cord  10   c   2  for heat source is connected to a position other than the catheter operating table X (for example, the main unit  10   k ). 
     The pump head portion  10   a  is designed as a small size pump head portion holding a single small diameter syringe  30 . It is preferable that the pump head portion  10   a  is a small size pump head portion for a syringe having a volume of 50 cc or less. The small size pump head portion  10   a  can be one having, for example, a weight of 500 to 3,000 g, a width (a length in a direction vertical to the axial direction of the small diameter syringe  30 ) of 50 to 150 mm, and a length (a length in the axial direction of the small diameter syringe  30 ) of 150 to 250 mm (in a shrunk state without syringe). 
     Further, as shown in  FIGS. 7(A) and 7(B) , the pump head portion  10   a  is provided with the plunger drive unit  62  for sliding the plunger of the small diameter syringe  30 . As shown in  FIG. 7(A) , the pump head portion  10   a  may be provided with the motor drive unit  61 . Further, as shown in  FIG. 7(B) , the plunger drive unit  62  may be designed so as to be connected, by means of a flexible shaft  63 , to a motor drive unit (not shown) provided separately for operating the pump head portion  10   a , thereby being driven by a driving force of the motor drive unit. As shown in  FIG. 7(B) , in the case of the plunger drive unit  62  being driven by the flexible shaft  63 , it is possible to make a weight of the pump head portion  10  lighter and a size thereof smaller. 
     Further, as shown in  FIG. 6(B) , the injecting system  100  according to this aspect of the disclosed embodiment comprises an arm stand  52  having the pump head portion  10   a  mounted thereon and being movable to an operating field. It is noted that herein “movable to an operating field” means that the pump head portion  10   a  can be moved to a position where the small diameter syringe  30  can be connected directly to the microcatheter  80   a  or a position in the vicinity of the wing portion  80   b  of the microcatheter  80   a  (for example, a necessary length of an extended injection tube of 500 mm or less, more preferably 250 mm or less). In this aspect, as shown in  FIG. 6(B) , the arm stand  52  is shown as a horizontal-vertical arm stand, in which a plurality of arms (two arms in  FIG. 6(B) ) is link-connected, and a position of the pump head portion  10   a  in a vertical direction and a horizontal direction can be adjusted. It is noted that the arm stand  52  is preferably designed as a thin arm so as not to obstruct a visual field in an operating field. 
     Further, in this aspect, the arm stand  52  is mounted on the catheter operating table X, and the pump head portion  10   a  can be moved toward the operating field by moving the arm stand  52  on the catheter operating table X. The arm stand  52  is detachably mounted on a side rail provided at a side portion of the catheter operating table X with a bracket or the like, and moves so as to be capable of adjusting its position in a vertical direction and a horizontal direction not to obstruct catheter treatment of an operator. It is preferable that the arm stand  52  is of light-weight and simple configuration so that it can be mounted on the catheter operating table X while holding the pump head portion  10   a  and the small diameter syringe  30 . It is noted that the structure of the arm stand  52  is not limited particularly as far as it can be mounted on the catheter operating table X and moved to an operating field or the vicinity of the operating field. 
     In catheter treatment, catheter operation is carried out while continuously moving the catheter operating table X in order to match the position of X-ray irradiation to the affected part of a patient. Therefore, the pump head portion  10   a  and the small diameter syringe  30  moved together with the catheter operating table X by mounting the arm stand  52  on the catheter operating table X. Accordingly, operability of the catheter is enhanced, and it is not necessary to provide an excessive length of the extended injection tube in consideration of movement of the catheter operating table X, resulting in disuse of the extended injection tube or exceedingly shortening of the length thereof easily. 
     As shown in  FIGS. 3(A) and 3(B) , the small diameter syringe  30  to be connected to the pump head portion  10   a  comprises a tubular cylinder member and a plunger (in the aspect, a long plunger  30   a , a short plunger  30   c ) slidably inserted into the cylinder member. 
     In this aspect, the small diameter syringe  30 , for example, having a volume of 30 to 50 cc and an inner diameter of 20 to 30 mm is used. It is more preferable that the volume of the small diameter syringe  30  is set to be 30 cc calculated from a maximum amount for one injection of a contrast medium in microcatheter treatment. This maximum amount for one injection can be obtained from, for example, an actual example of a series of imaging methods (angiography, CT imaging) required for embolotherapy of hepatic arteries. 
     As mentioned above, by using the small diameter syringe  30 , a small size and light-weight injector I is obtained after the small diameter syringe  30  is mounted on the pump head portion  10   a . Thus, the pump head portion  10   a  and the small diameter syringe  30  can be moved easily to an operating field or to the vicinity of the operating field with the arm stand  52 . Therefore, a large size system such as a system using a relatively large ceiling-suspension type pump head is not necessary, and introduction cost for the injecting system  100  can be reduced. Further, by use of the small diameter syringe  30 , reduction of an injection pressure as well as enhancement of operability can be achieved. 
     In this aspect, as shown in  FIGS. 3(A) and 3(B) , the small diameter syringe  30  comprises the short plunger  30   c  to be connected to the gasket of the small diameter syringe  30  and the long plunger  30   a  to be connected to the short plunger  30   c . The long plunger  30   a  is connected to the short plunger  30   c  with the long plunger connecting portion  30   b . The method of connecting the short plunger  30   c  to the long plunger  30   a  is not limited particularly, and these are connected, for example, by engaging. In this aspect, the small diameter syringe  30  can be in a connected state or in a separated state by sliding the long plunger  30   a  relative to the short plunger  30   c  in a direction vertical to the axial direction of the small diameter syringe  30 . 
     When filling a contrast medium in the small diameter syringe  30  by hand, the filling of a contrast medium in the small diameter syringe  30  by hand becomes easy in the connected state in which the long plunger  30   a  is connected to the short plunger  30   c . When connecting the small diameter syringe  30  to the pump head portion  10   a , the long plunger  30   a  may be formed in the separated state of being separated from the short plunger  30   c . As a result, filling by hand becomes easy, and in the case of injection by the injector I, since the long plunger  30   a  is in a separated state, as it can be seen from  FIGS. 5(A) and 5(B) , a length of the combined pump head portion  10   a  and small diameter syringe  30  in the axial direction can be reduced greatly. As a result, operability is enhanced and manipulation of catheter treatment becomes easy. 
     Further, in this aspect, the injecting system  100  is further provided with the outer peripheral temperature-maintaining heater units  10   c ,  10   d  mounted on an outer periphery of the small diameter syringe  30  and an outer periphery of the contrast medium bottle  70  suspended on a suspension stand. The outer peripheral temperature-maintaining heater unit  10   c  is connected to the heat source output terminal provided on the small size pump head portion  10   a . Thus, as mentioned above, the power cord  10   c   2  for heat source can be connected to the heat source output terminal  20   c  in parallel with the connection of the plunger of the small diameter syringe  30  to the plunger connection portion  20   b . Also, since the power cord  10   c   2  for heat source is connected to the heat source output terminal  20   c  of the pump head portion  10   a , the power cord  10   c   2  for heat source does not obstruct manipulation of catheter treatment. 
     The heat source output terminals for the outer peripheral temperature-maintaining heater units  10   c ,  10   d  may be provided on both of the pump head portion  10   a  and the relay box  10   h . In this case, heat source can be secured from the both of the pump head portion  10   a  and the relay box  10   h.    
     As mentioned above, the temperatures of the outer periphery of the small diameter syringe  30  and the outer periphery of the contrast medium bottle  70  can be maintained by the outer peripheral temperature-maintaining heater units  10   c ,  10   d , thereby allowing the contrast medium to be maintained at a predetermined temperature. As a result, an injection pressure for injecting the contrast medium can be decreased, and at the same time, can be maintained constant. Further, since the contrast medium is not cooled during the catheter operation, treatment using a catheter can be conducted continuously, and even in the case where during treatment using a catheter, other manipulation is required and the catheter operation is once suspended, it is not necessary to heat the contrast medium again. Therefore, a treatment time can be shortened. It is noted that the predetermined temperature is not limited particularly, and may be, for example, 37° to 50° C. The predetermined temperature is preferably 40° to 50° C., further preferably 37° to 39° C. 
     The outer peripheral temperature-maintaining heater units  10   c ,  10   d  are not limited particularly as far as the contrast medium can be maintained at the predetermined temperature. The outer peripheral temperature-maintaining heater units  10   c ,  10   d  are preferably film heaters using heat generation obtained by energizing an electrically conductive film. Also, it is preferable that the outer peripheral temperature-maintaining heater units  10   c ,  10   d  have flexibility making it possible to be attached on the whole surfaces of the outer peripheries of the small diameter syringe  30  and the contrast medium bottle  70 . As a result, winding and attaching on the small diameter syringe  30  is not bulky and does not obstruct catheter treatment. 
     Also, it is preferable that the outer peripheral temperature-maintaining heater units  10   c ,  10   d  are film heaters having flexibility making it possible to be attached on the small diameter syringe  30  and the contrast medium bottle  70 , and are formed from a transparent material in order to check the inside of the small diameter syringe  30  and the contrast medium bottle  70 . In this case, it becomes easy to check a remaining amount of the contrast medium in the small diameter syringe  30  or the contrast medium bottle  70 . As shown in  FIG. 12  and  FIG. 13 , the outer peripheral temperature-maintaining heater units  10   c ,  10   d  may comprise, for example, a flexible substrate B provided with a flexible transparent electrically conductive film C, a connector CN being capable of connecting to the heat source output terminal  20   c , and each of power cords  10   c   2 ,  10   d   2  for heat source. The sizes of the substrate B and the transparent electrically conductive film C can be changed appropriately depending on the size of the small diameter syringe  30  or the contrast medium bottle  70 . For example, the size of the outer peripheral temperature-maintaining heater unit  10   c  for the small diameter syringe  30  can be 70 mm×70 mm and a thickness thereof can be 0.2 mm, for example, in the case of a volume of the small diameter syringe  30  being 10 cc, and the size and the thickness thereof can be 70 mm×100 mm and 0.2 mm, respectively in the case of a volume of the small diameter syringe  30  being 30 cc. Further, the size of the outer peripheral temperature-maintaining heater unit  10   d  for the contrast medium bottle  70  can be 85 mm×185 mm and a thickness thereof can be 0.2 mm, for example, in the case of a volume of the contrast medium bottle  70  being 100 cc. An applied voltage of the outer peripheral temperature-maintaining heater unit  10   c  for the small diameter syringe  30  can be 1.5 to 3.0 V in the case of a volume of the small diameter syringe  30  being 10 cc, and can be 3.5 to 4.5 V in the case of a volume of the small diameter syringe  30  being 30 cc. Further, an applied voltage of the outer peripheral temperature-maintaining heater unit  10   d  for the contrast medium bottle  70  can be 5.0 to 7.0 V in the case of a volume of the contrast medium bottle  70  being 100 cc. For example, at an ambient temperature of 25° to 27° C., in the above-mentioned case of a volume of the small diameter syringe  30  being 10 cc, a target temperature of 37° to 50° C. can be achieved within 300 seconds by applying a voltage of 1.5 V to 3.0 V to the outer peripheral temperature-maintaining heater unit  10   c  (for example, a size of 70 mm×70 mm and a thickness of 0.2 mm) covering the whole small diameter syringe  30 . Also, at an ambient temperature of 25° to 27° C., in the above-mentioned case of a volume of the small diameter syringe  30  being 30 cc, a target temperature of 37° to 50° C. can be achieved within 300 seconds by applying a voltage of 3.5 V to 4.5 V to the outer peripheral temperature-maintaining heater unit  10   c  (for example, a size of 70 mm×100 mm and a thickness of 0.2 mm). Also, at an ambient temperature of 25° to 27° C., in the above-mentioned case of a volume of the contrast medium bottle  70  being 100 cc, a target temperature of 37° to 50° C. can be achieved within 300 seconds by applying a voltage of 5.0 V to 7.0 V to the outer peripheral temperature-maintaining heater unit  10   d  (for example, a size of 85 mm×185 mm and a thickness of 0.2 mm) covering the whole contrast medium bottle  70 . As mentioned above, the contrast medium in the vessel can be heated rapidly by applying a predetermined voltage to the outer peripheral temperature-maintaining heater unit. The outer peripheral temperature-maintaining heater units  10   c ,  10   d  may be attached to peripheries of the small diameter syringe  30  and the contrast medium bottle  70  using an adhesive double-coated tape so as to cover the peripheries thereof, or may be attached to peripheries of the small diameter syringe  30  and the contrast medium bottle  70 , for example using a hook-and-loop fastener, so as to cover the peripheries thereof. 
     Further, the outer peripheral temperature-maintaining heater units  10   c ,  10   d  may be provided with a temperature sensor for monitoring an outer periphery temperature of the small diameter syringe  30  and an outer periphery temperature of the contrast medium bottle  70 . A temperature of the contrast medium in the small diameter syringe  30  and the contrast medium bottle  70  can be controlled more accurately by providing the outer peripheral temperature-maintaining heater units  10   c ,  10   d  with the temperature sensor and controlling the outer periphery temperature of the small diameter syringe  30  and the contrast medium bottle  70  with the pump control device  10   f . Therefore, an injection pressure can be kept constant. Thus, while decreasing an injection pressure of the contrast medium within a predetermined range, an injection rate can be increased and at the same time, deviation between the set values of an injection amount and an injection rate set with the pump control device  10   f  and the actual values of an injection amount and an injection rate of the contrast medium to be actually injected can be decreased greatly, thereby making highly accurate injection of the contrast medium possible. The pump control device  10   f  may control an injection amount and an injection rate in addition to the temperature of the contrast medium. In case that the temperature of the contrast medium, an injection amount of the contrast medium and an injection rate of the contrast medium can be controlled with the pump control device  10   f , the contrast medium can be adjusted to a predetermined optimum temperature and can be injected in a desired amount at a desired injection rate. Further, the pump control device  10   f  may be configured so as to control the injection rate to be changed by every 0.1 ml/sec. In this case, the contrast medium can be injected according to a case of a disease of a patient and an affected part. 
     A method of use of the injecting system  100  is described below by referring to  FIGS. 1 to 8 . It is noted that the following method of use is only an example, and the injecting system  100  of the disclosed embodiment is not limited to the following method of use. 
     First of all, in a state of the short plunger  30   c  and the long plunger  30   a  being combined with each other as shown in  FIG. 3(A) , the small diameter syringe  30  is connected to the contrast medium filling line  70   a  (see  FIG. 4 ). Filling of the contrast medium into the small diameter syringe  30  and air vent operation are conducted through a manual push-pull operation by operating the long plunger  30   a  of the small diameter syringe  30 . 
     Next, as shown in  FIG. 3(B) , the long plunger connecting portion  30   b  of the long plunger  30   a  is slid in a direction vertical to the axial direction of the small diameter syringe  30  to be separated from the short plunger  30   c . After the long plunger  30   a  has been separated from the short plunger  30   c , the small diameter syringe  30  is connected to the plunger connecting portion  20   b  to connect the pump head portion  10   a  to the small diameter syringe  30  as shown in  FIG. 5(B) . 
     Next, as shown in  FIG. 4 , the outer peripheral temperature-maintaining heater unit  10   c  for the small diameter syringe  30  and the outer peripheral temperature-maintaining heater units  10   d  for the contrast medium bottle  70  are attached to the small diameter syringe  30  and the contrast medium bottle  70 , respectively, and the power cords  10   c   2 ,  10   d   2  are connected to the power source output terminal  20   c  of the pump head portion  10   a  and the power source output terminal of the relay box  10   h , respectively to start temperature maintaining of the contrast medium. 
     Next, as shown in  FIG. 2 , the wing portion  80   b  of the microcatheter  80   a  for fixing the syringe is connected to the small diameter syringe  30 . 
     Then, after optional injection setting suitable for a case of a disease has been made by means of the injection control section  10   f , injection of the contrast medium is started by operating any of the hand switch portions  10   b ,  10   g  or the foot switch portion  10   i.    
     It is noted that the above-mentioned injecting system  100  is not limited to the above-mentioned aspect, and various modification or addition to the configurations or sizes based on the purport of the disclosed embodiment can be made and are not excluded from the scope of the disclosed embodiment. 
     Experimental Example 
     An experimental example on an injection pressure for direct injection into the microcatheter (when the long size extended injection tube  51   a  (see  FIG. 6(A) ) is not used) which forms the basis of reduction of the injection pressure of the injecting system  100  of the disclosed embodiment is described below in detail, using  FIG. 8  and Tables 1 and 2. 
       FIG. 8  shows comparison of temperature transition of two bottles (about 180 ml) filled with hot water heated to 37° C. One bottle was wound with a film heater, and another bottle was not wound with a film heater. 
     Instruments used are 3-channel thermometer DATA LOGGER MTM-380SDJ, one wire temperature sensor TP-300 for measurement of an ambient temperature and two multi-purpose tape temperature sensors TS-04K (distal end of sensor: 4 mm wide x 100 mm long) for measurement of bottle temperature, all available from SATO SHOUJI INC. 
     As shown in  FIG. 8 , at an ambient temperature of 23° C., it is seen that while in the case of the bottle provided with no film heater, temperature thereof decreases up to a room temperature with a lapse of time, an initial temperature of 37° C. is kept even 70 minutes after in the case of the bottle provided with the film heater. Therefore, it is seen that by use of the film heater (an outer peripheral temperature-maintaining heater unit), the temperature of the contrast medium can be kept at a predetermined temperature even after a lapse of time. 
     Table 1 shows a comparison data on injection pressures between the case of injection of the contrast medium at room temperature and the case of injection of the heated contrast medium when the injection rate is changed by every 0.1 ml/sec. 
     Example 
     Injection pressures between the case where the contrast medium was heated and the case where the contrast medium was not heated (room temperature) with the microcatheter  80   b  being connected directly to the small diameter syringe  30  were compared. For heating the contrast medium, a film heater was wound on an outer periphery of the small diameter syringe, and the outer periphery temperature was measured with the temperature sensor used for measuring the temperature transition of  FIG. 8  and the film heater was controlled so that the outer periphery of the small diameter syringe becomes a constant temperature. The small diameter syringe used, the contrast medium, temperature and injecting conditions are as follows. 
     Small size syringe: Inner diameter: 22.3 mm, volume: 30 cc
 
Contrast medium used: Iomeron 300: 300 mgI/ml
 
Catheter used: Estream, outer diameter of distal end: 0.68 mm/outer diameter of proximal end: 0.97 mm, 135 cm
 
Setting of injection amount: Injection rate of 0.1 to 2.3 ml/sec
 
Total injection amount: 3 cc
 
Room temperature: 25° C.
 
Heating device: A film heater is wound on and attached to an outer periphery of a small diameter syringe
 
Heating temperature: 37° C.
 
     The results are shown in Table 1. 
     
       
         
           
               
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                 Room temperature 
                 Injection pressure 
                 Pressure 
               
               
                 Injection rate 
                 injection pressure 
                 under heating 
                 differential 
               
               
                 ml/sec 
                 (PSI) 
                 (PSI) 
                 (PSI) 
               
               
                   
               
             
            
               
                 0.1 
                 unmeasurable 
                 unmeasurable 
                 — 
               
               
                 0.2 
                 10 
                 10 
                 0 
               
               
                 0.3 
                 30 
                 30 
                 0 
               
               
                 0.4 
                 70 
                 70 
                 0 
               
               
                 0.5 
                 100 
                 100 
                 0 
               
               
                 0.6 
                 150 
                 130 
                 −20 
               
               
                 0.7 
                 170 
                 150 
                 −20 
               
               
                 0.8 
                 200 
                 180 
                 −20 
               
               
                 0.9 
                 250 
                 230 
                 −20 
               
               
                 1.0 
                 280 
                 240 
                 −40 
               
               
                 1.1 
                 310 
                 260 
                 −50 
               
               
                 1.2 
                 350 
                 270 
                 −80 
               
               
                 1.3 
                 400 
                 270 
                 −130 
               
               
                 1.4 
                 460 
                 270 
                 −190 
               
               
                 1.5 
                 500 
                 280 
                 −220 
               
               
                 1.6 
                 540 
                 280 
                 −260 
               
               
                 1.7 
                 590 
                 300 
                 −290 
               
               
                 1.8 
                 620 
                 310 
                 −310 
               
               
                 1.9 
                 680 
                 310 
                 −370 
               
               
                 2.0 
                 740 
                 340 
                 −400 
               
               
                 2.1 
                 790 
                 340 
                 −450 
               
               
                 2.2 
                 850 
                 360 
                 −490 
               
               
                 2.3 
                 Over 
                 370 
                 — 
               
               
                   
               
            
           
         
       
     
     As shown in Table 1, it is seen that the injection pressure under heating of the contrast medium is decreased significantly as compared with the injection of the contrast medium under room temperature condition, and the injection pressure difference especially in a region of a higher injection rate is large, namely ½ or less. Therefore, it is seen that an injection pressure can be decreased greatly by using a small diameter syringe and heating an outer periphery of the small diameter syringe as compared with a conventional injection device. It is seen that in particular when an injection rate is 1.3 to 2.3 ml/sec, a pressure differential becomes not less than 100 PSI and a significant effect can be obtained. 
     Further, Table 2 shows a comparison data between the injection pressures under heating at 37° C. at the injection rate of 1.5 ml/sec, 1.8 ml/sec and 2.0 ml/sec and the injection pressures at an injection test example using a general large size injector (see page 4 of the package insert of Medical Device Approval Number: 21800BZZ10121000). 
     
       
         
           
               
               
               
               
             
               
                 TABLE 2 
               
               
                   
               
               
                   
                 General large size 
                 Small size 
                   
               
               
                 Injection rate/ 
                 injector 
                 injector 
                 Pressure 
               
               
                 sec 
                 (PSI) 
                 (PSI) 
                 differential 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
            
               
                 1.5 
                 600 
                 280 
                 320 
               
               
                 1.8 
                 800 
                 310 
                 490 
               
               
                 2.0 
                 1000 
                 340 
                 660 
               
               
                   
               
            
           
         
       
     
     As shown in Table 2, it is seen that the injection pressure of the injecting system in Example of the disclosed embodiment decreased significantly as compared with the general large size injector. It is noted that in Example of the disclosed embodiment, the diameters of the catheter used were the outer diameter of distal end: 0.68 mm/outer diameter of proximal end: 0.97 mm, and a length thereof was 135 cm, while in the catheter Masters used on the large size injector of the comparative example, the diameters of the catheter used were the outer diameter of distal end: 0.68 mm/outer diameter of proximal end: 0.94 mm, and a length thereof was 125 cm. The injector was ZMA700 model A (Sheen Man Co., Ltd). As shown in Table 2, even under the disadvantageous condition of the length being longer by 10 cm in Example of the disclosed embodiment, it is seen that a very significant effect such that the difference in the injection pressure is half or more as compared with the catheter having nearly the same size. 
     Second Aspect 
     Second aspect shows an example where an outer periphery temperature-maintaining heater unit is applied to a syringe for manual operation, in which a suspension including an anticancer drug and a contrast medium used for treatment of embolus is filled. Hereinbelow, explanation common to the first aspect is omitted, and differential points are mainly described. It is noted that each configuration described in the second aspect can be applied to the first aspect, and each configuration described in the first aspect can be applied to the second aspect. 
     The system  1000  for temperature-maintaining and injecting a therapeutic suspension medicine for a microcatheter of this aspect comprises, as shown in  FIG. 10 , the microcatheter  80   a , the syringe  300  for manual operation, in which a suspension including an anticancer drug and a contrast medium used for treatment of embolus are filled, and the connecting portion  90  for connecting the syringe  300  for manual operation and the microcatheter  80   a . Further, on the outer periphery of the syringe  300  for manual operation is mounted the outer peripheral temperature-maintaining heater unit  10   cc  as shown in  FIG. 10  and  FIG. 11 . 
     In this aspect, as shown in  FIG. 10  and  FIG. 11 , the connecting portion  90  is mounted to the injector I and the small diameter syringe  30  attached to the injector I and the syringe  300  for manual operation can be connected to the connecting portion  90 . It is noted that the injector I and the small diameter syringe  30  are not limited to those used in the first aspect, and other structures may be used. Known syringes for manual operation can be used as the syringe  300  for manual operation. 
     The connecting portion  90  is not limited to the structure shown in the drawing as far as the syringe  300  for manual operation can be connected thereto. In this aspect, the connecting portion  90  has a three-way cock  90   a  for switching a flow path between a flow path from the syringe  300  for manual operation to the microcatheter  80   a  and a flow path from the small diameter syringe  30  to the microcatheter  80   a , a one-way valve  90   b  which is connected to the contrast medium filling line  70   a  connected to the contrast medium bottle  70  and is opened when filling the contrast medium into the small diameter syringe  30  and is closed when injecting the contrast medium, and a one-way valve  90   c  which is disposed between the small diameter syringe  30  and the three-way cock  90   a  and is closed when filling the contrast medium and is opened when injecting the contrast medium. Switching these valves enables filling of the contrast medium, automatic injection of the contrast medium and manual injection of a suspension used for treatment of embolus to be switched. 
     The outer peripheral temperature-maintaining heater unit  10   cc  mounted on the outer periphery of the syringe  300  for manual operation is heated by connecting a cord  10   cc   2  for heat source to a power source output terminal. The power source output terminal may be disposed on any device, and in this aspect, as shown in  FIG. 11 , the cord  10   cc  for heat source is connected to the heat source output terminal  20   c  provided on the pump head portion  10   a . In this case, for example, two heat source output terminals may be provided on the pump head portion  10   a . When the outer peripheral temperature-maintaining heater unit  10   cc  of the syringe  300  for manual operation is connected to the heat source output terminal  20   c  provided on the pump head portion  10   a , the power cord  10   cc   2  for heat source does not obstruct manipulation of catheter treatment, and operations from imaging of a site to be treated to treatment of embolus can be carried out in the same visual field. 
     According to this aspect, as mentioned above, the outer peripheral temperature-maintaining heater unit  10   cc  is mounted on the outer periphery of the syringe  300  for manual operation as shown in  FIG. 10  and  FIG. 11 . Thus, the temperature of the outer periphery of the syringe  300  for manual operation can be maintained and the suspension can be kept at a predetermined temperature in the same manner as in the outer peripheral temperature-maintaining heater unit  10   c  mounted on the small diameter syringe  30  described in the first aspect. As a result, reduction of an injection pressure due to decrease of a viscosity when injecting the suspension can be achieved and the injection pressure can be kept constant. It is noted that the predetermined temperature is not limited particularly, and for example, can be 37° to 50° C. The predetermined temperature is preferably 40° to 50° C., further preferably 37° to 39° C. For example, at an ambient temperature of 25° to 27° C., in the above-mentioned case of a volume of the syringe  300  being 10 cc, a target temperature of 37° to 50° C. can be achieved within 300 seconds by applying a voltage of 1.5 V to 3.0 V to the outer peripheral temperature-maintaining heater unit  10   cc  (for example, a size of 70 mm×70 mm and a thickness of 0.2 mm) covering the whole syringe  300 . Also, at an ambient temperature of 25° to 27° C., in the above-mentioned case of a volume of the syringe  300  being 30 cc, a target temperature of 37° to 50° C. can be achieved within 300 seconds by applying a voltage of 3.5 V to 4.5 V to the outer peripheral temperature-maintaining heater unit  10   cc  (for example, a size of 70 mm×100 mm and a thickness of 0.2 mm). Thus, by applying a predetermined voltage to the outer peripheral temperature-maintaining heater unit, the suspension medicine in the syringe can be heated rapidly. 
     In the treatment of embolus, the suspension medicine is injected by the syringe  300  for manual operation to a plurality of tumors of a patient or a plurality of nutrition blood vessels extending to the plurality of the tumors. It takes usually about 2 to 3 hours in total to complete this treatment, and the injection of the suspension medicine is conducted to plural sites at predetermined intervals. Therefore, though very complicated operations need be repeated in a clean operating field and unclean operating field in a conventional heating method, according to this aspect, basically no complicated operation is necessary and a treating time can be made shorter. This point is described below in detail. 
     In a conventional treatment of embolus, as shown in Kora Shinichi et al., Journal of New Remedies and Clinics, Vol. 61, No. 5, pp. 76-82, 2012, a suspension medicine was heated using a water bath. The conventional treatment of embolus is carried out as follows: 
     (1) Water (2 litters) is poured in a water bath and a power source is turned on.
 
(2) Proper amounts of anticancer drug and contrast medium are sucked with a syringe and poured into a mixing vessel.
 
(3) An operator moves to a location of the water bath.
 
(4) The mixing vessel is put in a test tube rack, which is then put in the water bath.
 
(5) The operator returns to an operating table.
 
(6) The operator moves to the location of the water bath.
 
(7) Immediately before use, the mixing vessel is taken out and every 1 ml is dispensed and injected with a syringe.
 
(8) The operator attaches and removes a needle to/from the syringe when sucking a mixture and mounting a microcatheter.
 
     In a conventional heating method using a water bath, in addition to the above-mentioned complicated operations, once the suspension medicine is taken out of the water bath, the suspension medicine is cooled from the time when the suspension medicine is injected at an embolus site to the time when the suspension medicine is injected at a next embolus site, and therefore, it is necessary to keep the suspension medicine in the water bath and repeat operation for taking out a necessary amount as required. Meanwhile, according to this aspect, even if a necessary amount for embolus at a plurality of embolus sites is filled in the syringe  300  for manual operation, since the suspension medicine is continuously heated by the outer peripheral temperature-maintaining heater unit  10   cc , reduction of an injection pressure is maintained and easy injection is possible and in addition, continuous administration to a plurality of embolus points is possible. Therefore, no complicated operation like a conventional method is required, and an injection pressure is reduced, injection is easy and a treatment time can be reduced. 
     As mentioned above, the system for temperature-maintaining and injecting a contrast medium for a microcatheter according to aspect 1 comprises an injector for injecting the contrast medium and a pump control device connected to the injector, wherein the injector for injecting the contrast medium comprises a pump head portion and a small diameter syringe connected to the pump head portion, wherein the system for temperature-maintaining and injecting the contrast medium further comprises an outer peripheral temperature-maintaining heater unit to be attached on an outer periphery of the small diameter syringe, and wherein the outer peripheral temperature-maintaining heater unit to be attached on the outer periphery of the small diameter syringe is connected to a heat source output terminal provided on the pump head portion. 
     According to the configuration of the above-mentioned aspect 1, the temperature of the outer periphery of the small diameter syringe can be maintained by the outer peripheral temperature-maintaining heater unit, and the contrast medium can be kept at a predetermined temperature. Thus, an injection pressure of the contrast medium when injecting it can be reduced and the injection pressure can be kept constant. Further, since the contrast medium is not cooled during a catheter operation, treatment using a catheter can be carried out continuously, and even if during treatment using a catheter, other manipulation is required and the catheter operation is once interrupted, it is not necessary to warm the contrast medium again. Therefore, a treatment time can be shortened. 
     Further, in aspect 2, the system for temperature-maintaining and injecting the contrast medium of aspect 1, further comprises an arm stand to which the pump head portion mounted, and the arm stand being capable of moving the pump head portion to an operating field. 
     According to the configuration of the above-mentioned aspect 2, it is possible to inject the contrast medium directly to the microcatheter, and due to disuse or significant shortening of the extended injection tube, further reduction of an injection pressure and decrease in cost (the extended injection tube is unnecessary or is shortened and a loss of the contrast medium is eliminated) can be achieved. 
     Further, in aspect 3, the system for temperature-maintaining and injecting the contrast medium of aspect 1 or 2, wherein the pump control device is capable of controlling a temperature of the contrast medium, an injection amount of the contrast medium and an injection rate of the contrast medium. 
     According to the configuration of the above-mentioned aspect 3, since a temperature of the contrast medium, an injection amount of the contrast medium and an injection rate of the contrast medium can be controlled by the pump control device, the contrast medium can be adjusted to an optimum temperature, and can be injected in a desired injection amount at a desired injection rate. 
     Further, in aspect 4, the system for temperature-maintaining and injecting the contrast medium of any one of aspects 1 to 3, wherein the pump head portion is connected to a drive unit for operating the pump head portion through a flexible shaft, and is remotely driven by a driving force of the drive unit. 
     According to the configuration of the above-mentioned aspect 4, since no motor drive unit is required on the pump head portion, the pump head portion can be made more lighter and small. As a result, it is possible to move the pump head portion smoothly to an operating field by a more compact arm stand. 
     Further, in aspect 5, the system for temperature-maintaining and injecting the contrast medium of any one of aspects 1 to 4, wherein a volume of the small diameter syringe is 30 to 50 cc and an inner diameter of the small diameter syringe is 20 to 30 mm. 
     According to the configuration of the above-mentioned aspect 5, the volume and the inner diameter of the syringe are small, and the syringe can be used suitably on the above-mentioned pump head portion, thereby achieving reduction of an injection pressure and enhancing operability of the arm stand while moving the pump head portion. 
     Further, in aspect 6, the system for temperature-maintaining and injecting the contrast medium of any one of aspects 1 to 5, wherein the volume of the small diameter syringe is set 30 cc, which is calculated from a maximum injection amount for one dose of the contrast medium in microcatheter treatment, wherein the small diameter syringe comprises a short plunger connected to a gasket of the small diameter syringe and a long plunger connected to the short plunger, wherein the small diameter syringe can be changed over to a connected state in which the long plunger is connected to the short plunger when manually filling the contrast medium to the small diameter syringe or to a separated state in which the long plunger is separated from the short plunger when connecting the small diameter syringe to the pump head portion. 
     According to the configuration of the above-mentioned aspect 6, by calculating a maximum injection amount of one dose of the contrast medium in microcatheter treatment, a necessary minimum syringe size of 30 cc is obtained, and a minimum plunger (short plunger) necessary for the injection and filling thereof is provided. In this case, in addition to miniaturization of the syringe and a smaller diameter of the syringe, due to a synergistic effect of a heat retaining property by the outer peripheral temperature-maintaining heater unit and good mobility of the arm stand and the small size pump head portion, it is possible to enhance a accuracy of the injection amount of the contrast medium and reduce an injection pressure. Further, according to the above-mentioned configuration, high accuracy and high rate injection of microdose aiming at reducing excessive high pressure injection can be achieved by a simple operation at the time of injection. Also, according to the above-mentioned configuration, large improvement of the control device and the like is not necessary, and by a light weight and downsizing of the pump head portion of the injector, simple and effective high accuracy and high rate injection of microdose becomes possible while making use of portability, which is extremely advantageous for use of a microcatheter at its operating site. Further, by combination of aspect 3 and aspect 5, the pump head portion becomes smaller and mobility thereof becomes satisfactory in the case where the pump head portion is a small size portable type by the lightest configuration with a remote drive method (an external motor) using a drive source from the outside. 
     Further, contrary requirements demanded for the small diameter syringe in operating the plunger (a longer plunger is preferable when filling manually while a shorter plunger is preferable when filling automatically or moving the pump head portion) can be satisfied by using a two-stage separable syringe. 
     Further, in aspect 7, the system for temperature-maintaining and injecting the contrast medium of any one of aspects 1 to 6, wherein the outer peripheral temperature-maintaining heater unit is a film heater using heat generation obtained by energizing an electrically conductive film, wherein the film heater has flexibility enabling the film heater to be attached to the whole surface of an outer periphery of the small diameter syringe and a contrast medium bottle, and is formed from a transparent material in order to check inside of the small diameter syringe and the contrast medium bottle. 
     According to the configuration of the above-mentioned aspect 7, while a small size and lighter weight of the small diameter syringe are maintained, the contrast medium can be maintained at a predetermined temperature, and the inside of the syringe and the bottle can be checked through the film heater formed from the transparent material. 
     Further, in aspect 8, the system for temperature-maintaining and injecting the contrast medium of any one of aspects 1 to 7, further comprising a contrast medium bottle containing a contrast medium to be filled in the small diameter syringe, wherein the system of temperature-maintaining and injecting the contrast medium includes a second outer peripheral temperature-maintaining heater unit being mounted on an outer periphery of the contrast medium bottle. 
     According to the configuration of the above-mentioned aspect 8, since not only the small diameter syringe but also the outer periphery of the contrast medium bottle is heated, a cooled contrast medium is not supplied to the small diameter syringe. Therefore, heating of the contrast medium can be accelerated and a temperature of the contrast medium to be supplied becomes stable. 
     Further, in aspect 9, the system for temperature-maintaining and injecting the contrast medium of aspect 8, wherein each of the outer peripheral temperature-maintaining heater unit and the second outer peripheral temperature-maintaining heater unit comprises a temperature sensor monitoring each of an outer periphery temperature of the small diameter syringe and an outer periphery temperature of the contrast medium bottle, and the outer periphery temperatures of the small diameter syringe and the contrast medium bottle are controlled to a predetermined temperature. 
     According to the configuration of the above-mentioned aspect 9, temperatures of the contrast medium in the small diameter syringe and the contrast medium bottle can be controlled more accurately. Therefore, an injection pressure can be maintained constant. As a result, while reducing the injection pressure of the contrast medium within a predetermined range, an injection rate can be increased, and in addition, deviations of the injection amount and the injection rate of the actually injected contrast medium from the injection amount and the injection rate which are set by the pump control device can be reduced greatly, and highly accurate injection of the contrast medium can be achieved. 
     Further, in aspect 10, the system for temperature-maintaining and injecting the contrast medium of any one of aspects 1 to 9, further comprising a microcatheter, a syringe for manual operation for containing a suspension including an anticancer drug and a contrast medium for treatment of embolus, and a connecting portion for connecting the syringe for manual operation and the microcatheter, wherein the connecting portion is mounted at an end of the small diameter syringe, wherein the system for temperature-maintaining and injecting the contrast medium includes a third outer peripheral temperature-maintaining heater unit being mounted on an outer periphery of the syringe for manual operation. 
     According to the configuration of the above-mentioned aspect 10, even if an amount of the suspension medicine necessary for embolus at a plurality of parts is collectively filled in the syringe for manual operation, by heating the suspension medicine continuously by the outer peripheral temperature-maintaining heater unit, reduction of the injection pressure is maintained and the injection can be carried out easily, and in addition, the suspension medicine can be administrated continuously for embolus at a plurality of parts. Therefore, no complicated operations need to be conducted like a conventional method, and it is possible to reduce an injection pressure, conduct the injection easily and shorten a treatment time. 
     Further, in aspect 11, a system for temperature-maintaining and injecting a therapeutic suspension medicine for a microcatheter comprises a microcatheter, a syringe for manual operation for containing a suspension including an anticancer drug and a contrast medium for treatment of embolus, and a connecting portion for connecting the syringe for manual operation and the microcatheter, wherein the system for temperature-maintaining and injecting a therapeutic suspension medicine further comprises an outer peripheral temperature-maintaining heater unit being mounted on an outer periphery of the syringe for manual operation. 
     According to the configuration of the above-mentioned aspect 11, even if an amount of the suspension medicine necessary for embolus at a plurality of parts is filled in the syringe for manual operation, by heating the suspension medicine continuously by the outer peripheral temperature-maintaining heater unit, reduction of the injection pressure is maintained and the injection can be carried out easily, and in addition, the suspension medicine can be administrated continuously for embolus at a plurality of parts. Therefore, no complicated operations need to be conducted like a conventional method, and it is possible to reduce an injection pressure, conduct the injection easily and shorten a treatment time. 
     Further, in aspect 12, the system for temperature-maintaining and injecting a therapeutic suspension medicine of aspect 11, wherein the outer peripheral temperature-maintaining heater unit is a film heater using heat generation obtained by energizing an electrically conductive film, wherein the film heater has flexibility enabling the film heater to be attached to the whole outer peripheral parts of the syringe for manual operation, and is formed from a transparent material in order to check inside of the syringe for manual operation. 
     ] According to the configuration of the above-mentioned aspect 12, while a small size and lighter weight of the syringe for manual operation are maintained, the suspension medicine can be maintained at a predetermined temperature, and the inside of the syringe can be checked easily through the film heater formed from the transparent material. 
     Further, in aspect 13, the system for temperature-maintaining and injecting a therapeutic suspension medicine of aspect 11 or 12, wherein the outer peripheral temperature-maintaining heater unit comprises a temperature sensor for monitoring an outer periphery temperature of the syringe for manual operation, and the outer periphery temperature of the syringe for manual operation is controlled at a predetermined temperature. 
     According to the configuration of the above-mentioned aspect 13, temperature of the suspension medicine in the syringe for manual operation can be controlled more accurately. Therefore, an injection pressure can be maintained constant. As a result, while reducing the injection pressure of the suspension medicine within a predetermined range, a sense of syringe operation does not change. 
     Further, each of the above-mentioned injecting systems relates to in particular a recent social issue on refugees involved in treatment of a cancer, and there is an increasing possibility of using the system for treatment of embolus (cutting off a nutrition source for a cancer by feeding an embolic substance from a microcatheter) which is expected by cancer refugees as a countermeasure for solving the problem, the system can be produced relatively easily since its structure is simple, and in use of the system, improvement of functionality (reduction of an injection pressure and high accuracy of an injection amount) and labor saving (reduction of a loss of a contrast medium and saving in cost of an extension tube for injection) are made. Thus, there is much expectation for practical use of the system since it is considered that the system can be used satisfactorily from the viewpoint of cost performance and there is no problem with safety. 
     EXPLANATION OF SYMBOLS 
     
         
           100  System for temperature-maintaining and injecting contrast medium 
           1000  System for temperature-maintaining and injecting suspension 
           10   a  Pump head portion 
           10   b  Hand switch portion at an operating field side 
           10   c  Outer peripheral temperature-maintaining heater unit for a small diameter syringe 
           10   cc  Outer peripheral temperature-maintaining heater unit of a small diameter syringe for manual operation 
           10   c   2  Power cord for heat source 
           10   d  Outer peripheral temperature-maintaining heater unit for a contrast medium bottle 
           10   d   2  Power cord for heat source 
           10   e  Motor box 
           10   f  Injection control section (pump control device) 
           10   g  Hand switch portion at an operation room side 
           10   h  Relay box 
           10   i  Foot switch portion at an operating field side 
           10   j  Monitor 
           10   k  Main unit 
           10   l ,  10   m ,  10   n ,  10   o  Cable 
           20   a  Syringe mounting portion 
           20   b  Plunger connecting portion 
           20   c  Heat source output terminal 
           20   d  Housing 
           30  Small diameter syringe 
           300  Syringe for manual operation 
           30   a  Long plunger 
           30   b  Long plunger connecting portion 
           30   c  Short plunger 
           40  Plunger 
           51  Fixed pole 
           51   a  Long size extended injection tube 
           52  Arm stand 
           52   a  Short size extended injection tube 
           61  Motor drive unit 
           62  Plunger drive unit 
           63  Flexible shaft 
           70  Contrast medium bottle 
           70   a  Contrast medium filling line 
           80   a  Microcatheter 
           80   b  Wing portion for fixing a syringe 
           90  Connecting portion 
           90   a  Three-way cock 
           90   b ,  90   c  One-way valve 
         B Substrate 
         C Transparent electrically conductive film 
         CN Connector 
         I Injector 
         S 1  Injection operation switch 
         S 2  Filling operation switch 
         SB Safety button 
         T 1  Temperature of the outer periphery of the contrast medium bottle in an elapsed time when using the outer peripheral temperature-maintaining heater unit 
         T 2  Temperature of the outer periphery of the contrast medium bottle in an elapsed time when using no outer peripheral temperature-maintaining heater unit 
         T 3  Ambient temperature 
         X Catheter operating table