the device which is represented in fig1 - 4 applies to the fixation to the body of a patient of a central venous catheter 1 , which has been placed in a large vein 2 of the body of the patient by the subcutaneous route , where the external part 1 a of catheter 1 exits from the skin p , and is attached to a support base 3 constituting a small closed and sealed reservoir , which is connected at its end opposite the catheter 1 to at least one catheter or external tube 4 which is in fluid communication with the catheter 1 for the administration of a medicinal product in reservoir 3 . one to five external catheters 4 can be connected to reservoir 3 to administer several different medicinal products in the vein 2 through the reservoir 3 and the venous catheter 1 . naturally , each external catheter 4 is connected to known perfusion means . according to the invention , the device comprises a housing 5 , which can be closed by a lid 6 , which is mounted by articulation on a side of the housing which is flat and consequently has a relatively small thickness , for example , approximately 8 - 10 mm . in addition , the device comprises a base 7 which is integral with the housing 5 by enclosing the latter to allow the fixation of the housing to the skin p of the patient , notably by a colloid . the housing 5 comprises two chambers which are in communication with each other : a first chamber 8 traversing the bottom of the housing is located above the puncture site of the catheter 1 and traversed by the external part of this catheter , and a second chamber 9 in which the reservoir 3 for connection between the external catheter 4 and the venous catheter 1 is located . as can be seen in fig2 , the chamber 8 can present a semicircular shape in a top view , while the chamber 9 can present a rectangular shape in a top view . given the relatively small thickness of the housing 5 , the two chambers 8 and 9 are approximately in the same plane and they communicate with each other through the intermediary of a passage 10 which is delimited by two lateral walls 11 , which are integral parts of the bottom of the chamber 9 perpendicularly with respect to the latter and inclined with respect to each other and converging towards the chamber 8 . the passage 10 is provided through a wall 12 which is an integral part of the bottom part of the chamber 9 which is adjacent to the chamber 8 and whose flat upper face is part of the flat upper part 5 a of the housing 5 . the reservoir 3 has a prismatic shape with a substantially rectangular transverse cross section , and its lateral walls 3 a , which are arranged perpendicularly to the bottom of the chamber 9 when the reservoir 3 is housed in the latter chamber , are inclined with respect to each other and converge with each other towards the wall at the end of the connection of the reservoir 3 at the external part 1 a of the catheter 1 . the reservoir 3 can comprise two wings 3 b , which are an integral part of the lateral walls 3 a symmetrically with respect to the longitudinal plane of the reservoir 3 . when the reservoir 3 is accommodated in the chamber 9 of the housing 5 , the narrowest part of this reservoir , which forms a nose , is accommodated in the passage 10 with the corresponding parts of the oblique lateral walls 3 a applied on the two lateral walls 11 of this passage , respectively . in this manner , the reservoir 3 is maintained in the passage 10 and it cannot move towards the chamber 8 . the lid 6 comprises two slender prismatic pads 13 , which are integral parts of its face and arranged symmetrically with respect to the longitudinal median plane of the lid 6 , and whose lateral opposite faces 13 a , which extend perpendicularly to the internal face of the lid 6 , are arranged obliquely with respect to each other in the same manner as the lateral walls 3 a of the reservoir 3 . with lid 6 closed , the two pads 13 penetrate into the chamber 9 and they are substantially applied by their oblique faces 13 a , respectively , against the oblique walls 3 a of the reservoir 3 to hold the latter bilaterally with respect to the housing 5 . in addition , the pads 13 are applied by their terminal flat faces 13 b respectively on the two wings 3 b of the reservoir 3 . in this manner , the reservoir 3 , with lid 6 closed , is perfectly immobilized in the chamber 9 , which prevents any accidental retraction of this reservoir and consequently of the venous catheter 1 , thus eliminating any risk of severe hemorrhage . the wings 3 b can be positioned at the bottom of the chamber 9 by two pins 9 a which are integral parts of this bottom and engage in two perforations of the wings 3 b . the lid 6 comprises two other pads 14 which are integral parts of its internal face and penetrate into the chamber 8 , with lid 6 closed , to partially close the latter . the two pads 14 are spaced with respect to each other so that they substantially extend the passage 10 , with lid 6 closed , and are arranged on either side of the external part 1 a of the venous catheter 1 . in addition , the terminal flat faces 14 a of the pads 14 are applied to the skin , with lid 6 closed , and , preferably , these terminal faces 14 a can comprise a colloid or be used as a support for an antiseptic or antimicrobial product . naturally , the external peripheral walls of the pads 14 have a shape which matches the peripheral walls which delimit the chamber 8 so that they are practically flush with the latter with lid 6 closed . the housing 5 comprises , on its upper face 5 a , opposite the wall 12 , several longitudinal grooves 15 , in the present case five , where each one has a semicircular transverse cross section and can receive an external catheter 4 . the lid 6 also comprises identical longitudinal grooves 16 , which are provided in its internal face and arrive above the longitudinal grooves 15 , respectively , of the housing 5 with the lid 6 closed , to maintain between themselves the different external catheters 4 , respectively , which are connected to the reservoir 3 . the lid 6 can be latched closed on the housing 5 by a ratchet mechanism , not shown , which can consist of a semicylindrical part of the free longitudinal edge of the lid 6 , opposite its articulation , and a paired groove on the upper external edge of the housing 5 , which receives the semicylindrical part . the base 7 for fixing the housing 5 consists of a seat of flexible material which is an integral part , for example , by molding , of the housing 5 so that the lower application face of this assembly on the skin of the patient is flat and full , except at the place where the chamber 8 opens , and so that it can match the anatomical shape of the patient to which the device is to be fixed . the lid 6 can be made of a single part by molding and , like the housing 5 and the base 7 , it can be made of a plastic material . according to this first embodiment , the base 7 is shaped , in a top view , so that it comprises two support holdfasts 7 a , each in the shape of an ear , which are located opposite the chamber 8 and an opposite bent part 7 b , which is adjacent to the chamber 8 . the lid 6 , and consequently the housing 5 , presents , in a top view , a rectangular shape with bent ends . the placement of the above - described device is carried out as follows . after the catheter 1 has been placed in the large vein , the reservoir 3 and the external part 1 a of the catheter 1 are introduced through the chamber 8 of the housing 5 , and the reservoir 3 is embedded in the passage 10 with application against the bottom of the chamber 9 . then , the external catheter ( s ) 4 is ( are ) connected to the reservoir 3 and arranged in their respective grooves 15 , unless they are already connected to the latter when delivered , in which case the catheter ( s ) 4 is ( are ) first introduced through the window 8 before being arranged in their respective grooves 15 of the housing 5 . then , the operator folds back the lid 6 to bring it into its closed position , in which the pads 13 completely immobilize the reservoir 3 in the chamber 9 and the external catheters 4 relative to the housing 5 , and the base 7 , which is covered on its internal face with colloid , is fixed to the skin of the patient . the colloid which is applied to the internal face of the base 7 can be protected by an appropriate film , not shown , which is withdrawn before the device is applied to the skin of the patient . the colloid can contain antiseptic substances to achieve a considerable reduction of the risk of infection . to visualize the puncture area of the catheter 1 , the cap 6 can be made of a transparent plastic material . the above - described device thus prevents any accidental extraction of the reservoir 3 from the venous catheter 1 and it can be adapted perfectly to the anatomical area of the patient , which makes the patient more comfortable and allows him / her to get about more easily . the device avoids the use of any fixation by means of sutures from the support or of the base 3 in the form of a reservoir to the skin . the second embodiment of the device of the invention , which is represented in fig5 , differs from the device of the first embodiment only in the absence of the two pads 14 and the presence of a relatively thin flexible membrane 17 constituting the bottom of the chamber 8 and comprising an orifice 18 , which allows the passage of the reservoir 3 with its wings 3 b and of the external part 1 a of the venous catheter 1 after the latter has been placed . the membrane 17 can comprise slits 19 which start from the edge of the orifice 18 to allow the passage of the reservoir 3 and of its wings through the orifice 18 by elastic deformation of the tongues defined between the different slits 19 extending radially in the case of a circular orifice 18 . in addition , the internal face of the membrane 19 , which is located in the same plane as the internal face of the base 7 and which can be prepared by molding to the latter , and the housing 5 can be coated with a colloid which makes it possible to apply the membrane 17 to the skin of the patient , and the colloid can comprise antiseptic or antimicrobial substances . according to the third embodiment of fig6 and 7 , the housing 5 is flat , as in the preceding embodiments , and in a top view it is in the shape of a semicircle which is extended by two parallel sides which are connected by a transverse side which defines the back wall of the housing 5 opposite the bent front wall , and the second chamber 9 , which opens directly into the chamber 8 , is defined by a slender hollow part with a semicircular transverse cross section , formed in the upper wall 5 a of the housing 5 by extending perpendicularly to the right lateral wall of the chamber 8 , of semicircular shape when seen from above . the hollow part 9 can taper from the end which opens into the chamber 8 to receive the sleeve - shaped base 3 of the catheter 1 , in the present case of the peripheral or arterial venous type with single channel , that is a single external catheter is connected to the sleeve 3 . the latter can have a general truncated tapered shape paired to the reception chamber 9 . the two pads 13 of the internal face of the lid 6 define , between themselves , a space whose shape matches the upper part of the catheter sleeve 9 to maintain the sleeve 3 in the housing 5 with lid 6 closed . the recess which defines the chamber 9 is delimited at the upper part by two lateral flat faces 9 a which are parallel to the upper face 5 a of the housing 5 and connected to the latter by two flanges 9 b extending obliquely by diverging opposite the chamber 8 in the case where the sleeve 3 is truncated . with lid 6 closed , the two pads 13 are simply applied with their end faces 13 b and their external lateral faces 13 c on the faces 9 a and the flanges 9 b , respectively . the base 7 for fixation of the housing 5 is defined by four ear - shaped parts 7 a , which are arranged symmetrically with respect to the longitudinal median plane of the device . the latter can comprise a flexible membrane 17 , which constitutes the bottom of the chamber 8 , as in the second embodiment . the device of the fourth embodiment of the invention , which is represented in fig8 - 14 , is particularly well suited to ensure the maintenance of a huber needle bent at a right angle , allowing access to a catheter which is introduced , for example , into a jugular vein , and connected to a subcutaneously - implanted perfusion chamber . the housing 5 of this device has lateral walls whose height is greater than the height of the housing 5 of each preceding embodiment , to take into account the vertical height of the needle 1 whose end must be introduced into the chamber which has been implanted under the skin . thus , the housing 5 is fixed above the implanted chamber through the intermediary of its base 7 , in such a manner that the chamber 8 is arranged vertically with respect to the implanted chamber to allow the introduction of the huber needle into the latter chamber through the skin of the patient . the reception chamber 9 of the sleeve 3 is provided through the corresponding lateral wall of the housing 5 in the upper part of the latter by opening into the chamber 8 , at the upper part of the latter and partially at the upper face 5 a of the housing 5 . the chamber 9 presents a transverse cross section which is approximately in the shape of a u whose lateral walls taper from the chamber 8 to hold the matching truncated part of the sleeve 3 , constituting the base of the huber needle 1 , which base forms a luer female conical connection to which an external tube 4 can be connected . the truncated chamber 9 for accommodating the base 3 is delimited at the upper part of its lateral walls by two catches 9 c , which are located on either side of a lateral wall , projecting from this wall and flush with the upper face 5 a of the housing 5 towards the base 3 , in such a manner that they are arranged above the latter base in its position where it is mounted in the housing 5 to retain the base 3 in the chamber 9 . each catch 9 c of a lateral wall of the chamber 9 is located opposite catch 9 c of the other lateral wall , thus defining a space between them which is transverse to the chamber 9 , and two catches of a lateral wall are spaced longitudinally at this chamber 9 . in addition , the catches 9 c are elastically deformable towards the bottom of the chamber 9 to allow the embedding of the base 3 in this chamber , as will be seen below . in the mounted position , the base 3 has its truncated end part of larger diameter projecting from the housing 5 , to which the external tube is connected , for example , through the intermediary of a male conical connection which is an integral part of this tube and engages in the base 3 . the base 3 is thus retained not only by the catches 9 c , but also by clamping in the truncated chamber 9 , and the part of the huber needle 1 which is curved at a right angle , and which is introduced into the chamber which has been implanted under the skin , extends approximately along the longitudinal or vertical axis of the chamber 8 whose general shape is cylindrical . an internal groove is formed in the chamber 9 between two longitudinally spaced pairs of catches 9 c , and opens at the upper face 5 a of the housing 5 between two adjacent catches . the role of the groove 9 d will be explained later with reference to fig1 and 13 . as is more apparent in fig8 and 10 , the housing 5 , with its base 7 , presents the general shape of a bell and it comprises , at the lower part of its wall into which the base 3 projects , a hollow part or notch 5 b , which is located above the base in the form of a sheet 7 , thus releasing to a large part the base 7 of this wall , conferring to it a flexibility which allows it to be molded to the anatomical area of the patient to which the housing 5 is to be fixed . similarly , the internal part of the wall of the housing 5 , which is opposite the wall from which the base 3 projects and located vertically with respect to the articulation hinge 20 of the lid 6 on the housing 5 , comprises a hollow part or notch 5 c which separates a large part of the base 7 from this wall to confer to it the flexibility required for the fixation of the housing 5 to the skin of the patient . the remaining parts of the base 7 are integral parts of the other lateral walls of the housing 5 , connecting to the two above - mentioned transverse walls . the lid 6 is latched to its position of closing the housing 5 by ratchet mechanisms which are known in themselves , and which can be located at the level of the lower edge of the front wall 6 a of the lid 6 and of an edge 5 d of the housing 5 on which rests the lower edge of the front wall 6 a , which comprises a substantially semicircular cutout 6 b , covering the base 3 in the closed position of the lid . as in the preceding embodiments , the housing 5 and the lid 6 can be made by molding a plastic material . the placement of the device of fig8 - 11 is carried out by first fixing the housing 5 to the anatomical area of the patient by the base 7 , whose internal face is provided with a colloid which comprises antimicrobial or antiseptic substances , the chamber 8 being arranged vertically with respect to the chamber which was implanted earlier under the skin of the patient . then , the operator pushes the base 3 of the needle 1 into the chamber 9 by embedding through elastically deformable catches 9 c , until the base 3 is applied on the bottom of the chamber 9 , where it is retained by the catches 9 c which rest on the base 3 . at the same time , the vertical part of the huber needle 1 is automatically implanted by its lower end into the chamber which was implanted through the skin of the patient . after the chemotherapy products have been administered to the patient , the retraction of the needle 1 is carried out by pulling the needle 1 upward and its base 3 against the elastic return force of the catches 9 c . once the huber needle 1 is implanted in the subcutaneous chamber , the operator folds the lid 6 to latch it to the housing 5 . this device thus eliminates any risk of accidental retraction of the huber needle and considerably lowers the risk of infection . the device of fig8 - 11 can be used with a huber needle 1 whose base 3 is connected to the external tube 4 which is forced on the truncated free end of the base 3 , forming an external pad 4 a as represented in fig1 and 13 . in this case , the part of connection with pad 4 a is embedded in the groove 9 d so that the truncated end part of the base 3 is held at the bottom of the chamber 9 with two of the catches 9 c covering the upper face of the base 3 and the connection tube is just covered by the two other catches 9 c immediately before exiting from the housing 5 . thus , the end part of the base 3 does not project from the housing 5 , since it is accommodated in a part of the chamber 9 which opens towards the chamber 8 , and the remaining part of the base 3 projects into the chamber 8 with the vertical part of the huber needle 1 being located in proximity to the corresponding lateral face of the chamber 8 , as can be seen in fig1 . naturally , the truncated end part of the base 3 has dimensions such that it is received in the part which has the same shape as the opening from chamber 9 into chamber 8 . as far as the rest is concerned , the placement and the retraction of the huber needle is carried out in the same manner as in fig8 - 11 . in summary , the device of the invention which is the object of each one of the above - described embodiments effectively protects the cutaneous puncture area from infections , it allows examination of the puncture site and it eliminates the use of daily dressings for cleaning the wounds . in addition , the flexibility of the fixation base of the device makes it possible to adapt it to the anatomical area of the patient where it is to be arranged , and it confers greater comfort to the patient , allowing him / her to get about and move more easily . in addition , the device avoids the use of fixation of the catheters to the skin by means of suture threads . the use of a colloid for fixing the base to the skin , which can contain antiseptic and antimicrobial substances , considerably decreases the risks of infection .