DEVICE FOR APPLICATION IN BLOOD VESSELS OR OTHER DIFFICULTLY ACCESSIBLE LOCATIONS

Abstract: Device comprising a helically shaped spiral spring (36) and means (40, 41) for bringing the spring (36) to expand from a first state of a certain diameter to a second state of larger diameter and vice versa, characterized thereby that said means (40, 41) are arrnged to rotate the ends (38, 39) of the spring (36) relative to each other with maintained length of the spring so that the transition from said first state to said second state takes place by reducing the number of spring turns within said length and the corresponding increase of the pitch of the spring, or to supply to a given length of the spring further spring material at at least one end of the said length of the spring so that the transition from said first state to said second state takes place independent of pitch and number of spring turns within the said length; and a method for transluminal implantation of an intravascular prosthesis using the said device.

Description: DEVICE FORAPPLICATIONINBLOOD VESSELS OR OTHERDIFFICULTYACCESSIBLELOCATIONS TECHNICAL FIELD The present invention relates to a device which can be applied within for example blood vessels of the body of a living animal or a living human being. The device comprises a helically shaped coil spring that can be expanded from a first state of a certain diameter to a second state of larger diameter ana vice versa. The invention is particularly useful for mechanical transluminal implantation by means of an expanding, self-fixating appliance for blood vessels, respiratory tracts or the like. By means of the device of the present invention also the inner walls of damaged blood vessels or other organs may be lined with artificial tissue which may be porous. In surgical and other medicinal techniques there is sometimes a need of inserting and expanding a device in for example blood vessels, urinary tracts or other difficultly accessible places which has for its function to widen the said vessel or tract, the device being optionally left in position to provide for permanent widening. The device according to the present invention may be used in many medicinal applications and, as examples, there may be mentioned utilization in different types of aneurism reflected by seme form of vessel widening, or the opposite, stenosis, which involves contraction of blood vessels. More particularly, the invention thus may be used to support and keep open vessels of venous systems, to support artificial vessel elements, to close pathological vessel failures, to bridge pathological vessel dilatations and ruptures in interior vessel walls or to stabilize bronchial tubes or bronchi. The device of the present invention may also be designed to act as a filter * for thromboses, for example by application in Vena Cava Inferior to prevent the formation cf lung emboliae. However, the invention is not limited to the applications mentioned herein which must be considered as solely exem lifying. BACKGROUND ART. In U.S. patent specification " 5,868,956 there is described a device which after insertion into for example blood vessel may be. expanded. The active part of this device is based en the use cf metal alloys having so-called ' * ιr,emor3 r function", i.e. a material which when heated will recover its initial eon- figuration. In this prior art the heating of the material is provided b3 * electrical hearing, the device being inserted at the location of interest. However, this known technique possesses the essential disadvantage that electrical resistance heating must take place in connection to surrounding sensitive tissue which may be damaged in the heating. It is true that it is stated in the patent specification (ef.eol.3, lines 42-46) that when inserting the device into a blood vessel the patient's bleed functions as a cooling medium. However, also bleed is a heat-sensitive material which when heated can be subjected to undesirable coagulation. SUMMARY OF THE I YΞ TIC-.:. The present invention has for its purpose to provide for an expansible device whereby the drawbacks of the known technique are avoided. The present inventio is based en the utilization of a device comprising a helically shaped coil spring BJ B ©OWGWAt which can be subjected to contraction cr expansion. The invention is based on the principle that the spring will be given smaller or larger diameter by means of suitable mechanical means. This is possible to do in two principally different wa τ s which all fall within the framework cf the same basic inventive concept. In the following there are given examples of two of these ways. A first way consists in rotating the ends of the spring relative to each other while maintaining a con¬ stant length ofthe spring so that the transition from a smaller spring diameter to a larger one takes place b"- reducing the number of spring turns within said length and the corresponding increase cf the pitch of the spring. A second way to change the diameter of the spring consists in removing part of the spring mate¬ rial from a given length of the spring at at least one end of the said length cf the spring, so that the transition from a state cf larger diameter to a state of smaller diameter takes place independent of pitch and number of spring turns within said length. In order to expand the spring in said other way the reverse operation is, of course, performed, i.e. additional spring material is supplied to the said length of the spring. This second waj ** cf changing the diameter of the spring ma.y 3 if desirable, take place while maintaining pitch and number of spring turns within the said length. Both said ways r.a3 r , of course, be used to change the coil spring from a state cf larger diameter- to a smaller diameter and vice versa. In a preferred embc irr.ent cf the device according to the invention the larger diameter cerreε ends largely to unleaded ccn iticr. of the coil spring. This means that the contraction cf the coil spring takes place against its spring resistance, whereas its BAD ORIGINAL expansion takes place under release of the tension to unleaded state. While utilizing the above-outlined first way cf contracting cr expanding the spring one end of the spring may be attached to a shaft which is centrally arranged inside the spring, whereas its other end is connected to a sleeve surrounding said shaft. Ey turning the shaft and/or the sleeve relative tc each other the diameter of the spring can hereby be decreased or increased. In order to make it possible to leave the coil spring also after application at a location the shaft and the sleeve can be remcvably connected to same. When using ceil springs of a minor dimension in regard to the spring material problem may arise in connection with applying the spring and expanding same at the intended location in that the separate material turns of the spring may fall to one side so that the desired supporting effect will net be obtained. In order to eliminate cr reduce the risks fcr such spring collapse an axially extending guide bar- can be arranged at the circumference of the spring, on which bar guide means are isplaeeably arranged through which the spring material can move anger. ially in connection with the contraction cr expansion cf the spring. In an alternative embe i ent cf the device according to the invention an axially extending support member can be arranged at the ci cumfere ce of the spring which carries fixed guide means thrcugh which the spring material can move tar.gentially in connection wit the expansion or contraction cf the sprin . In certain instances, fcr example in case cf hernia cr tissue rupture, it may be desirable to BA0ORIGINAL apply a spring which over a limited part of its length has a larger density between the spring turns. This can in principle be done in two different a τ ε. One alternative is based on distributing the above-mentioned fixed guide means in such a manner as to obtain over a certain length of the spring a larger density cf turns. The second alternative consists in initially manu¬ facturing the spring with one cr several sections of higher turn density. Also a combination of these two alternatives maj-, of course, be used in practice. It is to prefer, in view of the above-indicated risk for collapse, to make the spring material in a flattened form cr in the fcrm of a band, the larger dimension of the material as seen in cross section extending axially. It is particularlj- preferred to design the spring with an essentially rectangular cross section. In a particulariy preferred embodiment of the device of the present invention a C3 r lindrical tubular carrier body is arranged within the coil spring comprising a central part and being provided with end sections at the enzlE cf the spring pivotal . relative to each other, the ends cf the spring being connected to the respective end sections. The device furthermore includes means wi h the help cf which the said end sections can be rotated relative to each other in order to expand or contract the spring. Said means fcr rotating the end sections suitably c-cmprise a coaxial cable connected to the one end εeeticn, the interior concentric element of the cable extending through the carrier bodj 7 and being at the end connected to the other end εeeticn, rotators being arranged at the outer free end cf the ccaxial cable for providing the desired relative movement between the end sections. In connection with this latter embodiment of the BAB.ORtGINAL device according to the invention the end sections of the carrier body may be axially diεplaeeable relative to the central part so that in the gap between the central part and the respective end sections the end of the spring can be releaεably attached. In this case it is suitable to arrange at least one end section or part thereof axially diεplacεable by means of a member arranged at the free end of the coaxial cable. The last-mentioned member may optionally perform the two-fold function of both to be used fcr rotating the second end section and providing for the axial displacemen . In a particularly preferred embodiment of the device according to the present invention there is arranged an axially extending support member at the circumference of the spring, at the one end of which the spring is attached and at the other end of which there is provided a fixed guide member through which the spring material can move in ccnnεctlcn with the contraction or expansion cf the spring. Alternatively, at both ends of the support member there may be arranged fixed guide means, through which the material of the spring can move. This embodiment enables simultaneous feeding in both directions of spring material at both ends of the spring. According tc an alternative embodiment the device of the invention comprises an elongated carrier bo about which the spring is arranged, a cassette magazine arranged at one end cf the carrier body including a cylindrie cassette housing, a feed C3 r linder eccentrically- mounted therein which at its periphery engages the inside of the cassette housing, using this device the spring can be moved for contraction cr expansion in the nip between the cassette housing and ^ABORIGINAL OMPI the feed cylinder by rotating the latter in one direction or the other. In this embodiment the cassette housing may be provided on the inside with a trapezoid thread in which the spring can glide. Moreover, it is suitable to provide the feed C3 r linder on its exterior with a friction ccating, for example of rubber or plastic. In surgical operations for implanting prostheεes it is sometimes .desirable to provide fcr a porous tissue inside fcr example a blood vessel for some reason. In connection hereto it is possible in accordance with the invention to provide for a stocking of porous tissue outside cr inside the spring which can be implanted at desired location together with the spring. The stocking may either by εtretchability of the tissue or by overlapping folding be adjustable to the spring diameter in connection with the expansion of the spring. In regard to the choice of material for the components involved in the device acccrding to the invention it is primarily the coil spring which is critical in this respect. For the spring there should be selected a medicinally ** acceptable material, for • example a stainless steel cr * ether metal alley cr a • plastic, used in similar connection. Other characterizing features and alternative embodiments will be evident from the following de¬ scription and the appended patent claims. A further essential advantage cf the "technique of the present invention compared with for example that of the abeve-mer.ticned U.S. patent 3,Etc,956 lies in the fact that the device acccrding to the invention is reversibly operable, i.e. the spring .may first after application be expanded, whereafter before releasing the spring from the other members cf the device one can check, for example by X-ra3 7 ε, that the position and fixation of the spring is acceptable, whereafter it can be released and the remaining part of the device removed from the location of application. This possibility is not at all available In the device according to the just mentioned U.S. patent, since the expansion initiated in this known technique is non-reversible. EXAMPLES The invention will in the following be further described ~ oy exemplifying embodiments in connection with the appended drawings. It should be noted that these specific embodiments are only intended to be illustrative and not restrictive in regard to the εcope defined by the claims. In the drawing the following is illustrated: Fig. 1 shows a perspective view of a ceil spring for use In the device according to the invention; Fig. 2 shows a side view of the ceil spring con¬ taining a carrier body and showing the spring in expanded state; Fig. •shows the same device as F g. 2 but showing the spring in contracted state; Figs. 4-7 illustrate dlagrammaticallj- the principle cf removing spring material from a coil spring in accordance "with the invention; Figs. S and 9 -h r. a variant based on the same principle as that according to Figs. 4-7; Fig. 10 shows diagram atically the possible per¬ formance of the ceil spring under the influence cf external forces: Fig. II shows a detail of the coil spring using guide means; BADORIGINAL Fig. 12 shows in enlargement a detail of the device of Fig. 11; Fig. 13 shows a detail section along line I-I in Fig. 12; Fig. 13A shews diagrammatically a spring pro¬ vided with support member and a fixed guide member; Fig. 13E shews a detail of the embodiment of Fig. 13A; Fig. 14 shows diagrammatically a spring provided with support member and guide member; Fig. 15 shows a detail of an alternative guide member; Fig. 16 shews the guide member according to Fig. 15 seen from above; Fig. 17 shows diagrammatically an overall view of an embodiment cf the device of the invention; Fig. 18 shews in overall view an alternative embodiment of the device according to the present invention; Fig. 19 shews enlarged a detail of an alternative embodiment of the device cf Fig. 18; Fig. 20 shows the detail according to Fig. 19 in side view; Fig. 21 shows a device according to the invention fcr the application of porous tissue; Fig. 22 shows an embodiment using a flat spring material with recesses; Fig. 23 shows an embodiment designed as a ladder-like double spring: Figs. 2 and 25 show an embodiment of the coil enabling overlapping between adjacent turns; Fig. 2β shews a modified- embodiment of the spring of the device, the spring providing for filtering function; and Fig. 27 shews an alternative embodiment where BADORIGINAL OMPI the spring has been covered with porous tissue. In connection with the following description it is assumed that the device according to the invention is utilized in connection with a blood vessel contain- ing a defect location, where the blood vessel has relatively large diameter, whereas the location where the device is introduced into the blood vessel has a smaller diameter. However, the device according to the present invention may be used, also in cases where it shall be inserted in a blood vessel of a relatively constant diameter thereby to avoid damages to the inner walls of the blood vessel in connection wit inserting the device for transfer to the location where applica¬ tion shall take place. Thus, the device according to the invention can be inserted at an easily accessible location where the blood vessel in question has a relatively small diameter due to the fact that the coil spring of the device can he maintained in contracted state by mechanical 'iseanε, said state being small or smaller than the diameter of the blood vessel at the location of insertion. The device Including the coll spring is then inserted into the blood vessel and transferred to the defective location where the coll spring in a mechanical manner is expanded until the cuter diameter of the spring Is equal to cr somewhat larger than the diameter of the blood vessel at the defective location. Then the coil spring is suitably released from the other members cf the device acccrding to the invention and may a ter removal of the remaining part of the device thus be left at the defective lccaticn for carrying cut its supporting function from the inside. If the diameter of the spring in unloaded state Is selected somewhat larger than the inner diameter of the blood vessel the spring will fixedly engage the walls of BAD.άR-OINAL the vessel by a certain specific pressure the magnitude of which can be precalculated and thus selected as desired. In drawing figures 1, 2 and 3 there is shown in principle how a helically shaped coil spring according to an embodiment of the invention can be subjected to change in diameter. Fig. 1 shows diagrammatically a coil spring having diagrammatically shewn longitudinal axis 2. The ends of- the spring are designated 3 s-^ct 4. The ceil spring of Fig. 1 is assumed to be in a position of rest, i.e. It has taken the shape it has when not effected by external forces. If now the ends 3 . °£ the spring are rotated around the longitudinal axis 2 in the direction of arrows 5, 6 under the influence of an external force the spring diameter will decrease at the same time as the number of turns increase in a corresponding degree. In Fig. 2 there is. shown a coil spring 1 in position of rest as seen in a side view. In Fig. the same spring 1 is shown after re¬ duction of the diameter has been provided for in accord with the description relative to Fig. 1. In its position in Fig. 3 spring 1 has been given a diameter d3 which is one third of the diameter d2 of Fig. 2, whereas the number of turns iε three times as large as the number of turns in position of rest. Since the length L cf the spring is main¬ tained unchanged the pitch ≤3 of the helical spring in the position according to Fig. i £ c^s third of the pitch s2 of the position of rest according to Fig. 2. In Figs. 2 and 3 there is shown with dashed lines a cylindric central body 7 having fcr a function to stabilize the spring 1 in its contracted condition a e. tc Fig. 3- In Figs. - there iε shown the principle for another embodiment ace. tc the invention, according to which the diameter change cf the coil spring iε provided without changing the pitch cf the spring. A ceil εpring 1 iε ace. to Fig. 4 in its position of rest with diameter b4, length L4 and pitch ε4. In Fig. 5 the same spring is shewn but BAD. ORIGINAL " ζw OMPI having the diameter d reduced to about half of the dia¬ meter d4 according tc Fig. 4. However, in this state the spring has two parts A and E of different pitch. Fart A has the same length L4 and pitch ε4 as the spring has in position of rest, whereas part Ξ has a length L5 which is considerably smaller than L4 and a pitch s5 which is con¬ siderably smaller than ε4. The reduction of the diameter from the position of rest according to Fig. 4 to the state according to Fig. 5 can be provided by rotating the ends of the spring in the same manner as shewn in Figs. 1-3* Dividing up the contracted spring in two zones of differ¬ ent pitches can thus be provided by means of εuitable mechanical aids. In Fig. 6 there iε shown the same spring 1 as in Fig. 4 but having a diameter dβ which has been reduced to about half of diameter d4. The spring has two parts C and D. Part C has the same length L4 and pitch s4 aε the εpring haε in its position of rest. In part D spring 1 forms a concentric flat εpiral spring. In Fig. 7 there iε shown the spiral spring ace. to Fig. 6 but in an end view, from which the appearance of part D iε clear. In this embodiment the total length IA of the spring and the pitch s4 Is thus the same as In the position of rest of the εpring. The change of εpring 1 from poεiticn of rest to the state according to Figs. 6 and 7 can be provided by using εuitable mechanical devices. In Figs. 1-7 there has thus been shown how the diameter cf helically shaped coil springs according to the invention can be changed to enable for example surgical operations. In the following there will be described εome different practical solutions to provide fcr the desired expansion cr contraction of the coil spring. Part 33 of the embodiment acccrding to Fig. 5 πiay also be considered as a storage part of the coil BADOaiGINAL spring material from which in the expansion the part A of spring material is supplied. In Figs. 8 and 9 there is εhown a εide view and an end view, rεεpεctively, of a device in which the just mentioned principle is applied. In the storage part B the spiral turns lie close to each othεr. Figs. 8 and 9 show diagrammatically how the feeding can take place through a nip formed between two counter-rotating small feeding rollers 15 and l6, wherεbj ** spiral material iε progressively and controlled fed cut at the end 17 of the roller nip in the direction of arrow 18. The dashed line 19 in Figs. 8 and 9 shows part A of the coil εpring after expansion to position rest has taken place. In connection with application of coil springs by means of the devicε according to the present invention it is, of course, possible after the application to change the length of the spring as required by manipulation from the outside for adaptation to different situations. Thus, the spring may before, during and after the expansion be axially compressed in order to then be axially extεndε tc for example neutral unloaded state and even to an expanded state beyond neutral. 'This later case may result in certain further stabilization of the spring in view of tension stored therein. When applying the technique according to the present invention for surgical operations in the human bod 7 the diameter of the coil εpring in contracted or .reduced state is suitably not larger than 8 to 10 mm. The diameter in expanded state may lie between 12 and 30 mm. An expansion such as fcr example from 8 mm to 12 mm, i.e. an expansion degree cf 5-0 or an expansion number of 1.5 (JL2 = 1-5) - possible with fcr example a coil spring made cf a thread of stain- less steel having a thickness of about 0.3 mm- However, it has been found that by using this thread material it is not possible to manufacture a coil εpring which in its position of rest in expanded state has a dia¬ meter of about ° IEIE ' Investigations have shown that for all εpring materials o . interest there is a relation between material thickness and expansion number. The relation is depending on the material but in general the higher the expansion number desired the thinner the thread material to be selected. As an example there may be mentioned that to make possible a position of rest at 30 E™ diameter from a contracted εtate of 8 mm in diameter, i.e. an expansion number of «8 therε will be required a εteεl band of stainless material having a width cf 1 mm and a thickness cf about 0.15 mm. Quite generally a suitable interval concerning thread or band thickneεε iε about 0.08 to 0.30 mm. Aε rεgardε the breadth of band material a suitable interval is about 0.3 to 2 mm. In- other words this means that for utilizing the technique according to the presεnt invεntion fcr surgical purposεs in most caseε one haε to utilize a thin material in thread or band form for manufacturing the coil spring. Howεver, a coil spring based en such material gives satisfactory support when applied in for example a defective blood vessel. In practice it has been found that coil springs adε of thin atεrial have, a tendency in expanded state to be mechanically inεtabie. Thus, thiε results in tilting or collapse cf the εpring after its application. In Fig. 10 there is shewn diagrammatically how a coil εpring 1 made cf a thin material can perform in view cf instability- in expanded position after it has been applied. r.e cashed line indicates the vessel wall of a blood vessel wherein the εpring haε been expanded. Such instability of the coil spring is often not acceptable, since the coil spring does not perform BADORIGINAL its intended function to eliminate the said defect but can rather act restricting on the flow of blood. According to the invention the risk for such spring collapse can be eliminated or at any rate essentially prevented by providing the ceil spring with rigidifying devices active with the coil εpring both in contracted and in expanded εtate. Drawing figureε 11, 12 and 1 illustrate an embodiment of the device according to the invention provided with such rigidi- fying mεanε. Fig. 11 shows diagrammatically part of a coil spring which in contracted state is designated 21 and in expanded state iε designatεd 21a. In the figure threε guide member 22 for the coil εpring arε shown. Guide members 22 are arranged on a common flexible but relatively rigid thread 2 at a mutual distance of sl2, as Is clear from Fig. 11. Fig. 12 shows a detail of the device of Fig. 11 in enlargεment and Fig. 1 shows a section along line I-I in Fig. 12. As is clear from Figs. 12 and 13 the coil spring 21 extends through a hole or a recess 24 in guide member 22, whereas thread 2 extends through the hole 25 of guide member 22. In connection to the embodiment illustrated in Figs. 5 and 6 it iε suitable to arrange guide members 22 fixedly attached tc thread 23. In this manner the pitch sl2 will be maintained at contracted aε well aε expanded εtate, all in conform! y with the earlier deεcription in connection with drawing figures 5 and 6. Fig. I A shows an embodiment cf a cell εpring in expanded εtate stabilized by means of a fixed guide member. Ceil εpring 21 which iε suitably made of a thin metal band iε as itε end 25a fixedly attached to the axial support member 23a, suitably ccnsiεting of one flexible band or two flexible bands attached to each to each other. The other end 21b of the coil εpring 21 iε connected to support member 23a by means of a single fixed guide mεmbεr 22a in the form of a loop having a rectangular opening. It has been surprisingly found that spring 21 in this embodiment is sufficiently stable for practical use and that it is sufficient that the end sectionε of the spring are stabilized and connected to each other by means of support member 23 . The advantage cf this embodiment containing one εingle guide member is that the expansion or contraction of the spring Is facilitated by the fact that the spring need to pass only through one single guide member. Fig. 133 shows in enlargement a suitable design of guide member 22a and its connection to support member 23a. Guide member 22a is formed by using a band having a loop-like protrusion which, together with support member 23a, forms a rectangular recess 22a. In said recesε εpring band 21 may easily slide while stabilized at the same time. Alternativelj- * , the last dεscrlbed embodiment according to ' Figs. 13 and 13B can be modified by arranging a fixed guide member at each end of support member 23a. In this manner spring band material can be fed into or fed out from both ends cf spring 21 simultaneously which can be of advantage at large expansion numbers when larger lengths of εpring band material have tc be stored at both ends of the εpring in connection with the contraction of the εpring. In connection tc this embodiment even better stabilization of the εpring in expanded state will be obtained if the distance between fixed points 21a, 22a is made longer than the normal length cf the spring in neutral, un-lcaded εtate. In embodiments in accordance with Figε. 2 and 3 guide members 22 are, however, diεplaceably arranged on thread 23. whereby the pitch of the coil εpring can be BADORIGINAL changed in accordance with what haε been earlier described. Fig. 14 shows diagrammatically in a side view a coil spring thus stabilized in expanded rest position. It has been previously indicated that the matεrial of the coil spring suitably is in thrεad or band form, i.ε. that the material of the coil εpring in an axial cross section haε a round or flattened εhape. It haε bεεn found that coil εpringε made of band-formεd matεrial are more εtable and have less tεndεncy to tilt or collapse. As a rule, however, the band width should not exeεεd 1 to 1.5 mm for medicinal reasons. Larger width hampers the growth of tissue and results in inferior fixation in view cf lower specific engagement pressure. High specific engagement pressure is to prefer since it gives a better fixation which is essεntial in applications In blood vεsεelε, where thε pulsε rhythm can result in diεplacement of an applied εpring in an axial direction. One way of improving fixation is to ccarεen the outer surface of the spring material by for example blaεtering. Thε εpring material may alεo by punching be provided wit outwardly extending protrusions or, alternatively, the band material can be perforated, for example by punching or by using a laεer, whereby better fixation will be obtained and the growth cf tissue in the area where the spring has been applied iε facilitated.' Fig. 15 shews in enlargement an embodiment of a guide member providing fcr good spring stability also at large expansion numbers. Guide member 27 is provided with a rectangular recess 23 for guiding a band-formed coil εpring 29, aε shewn in crGεs section. The dimensions of recess 25 are suitably selected so that the coil εpring member 29 can easil ** εlidε through the rεceεs when thε spring is expanded or contracted. At the same timε it is prεve tεd that the coil spring tilts so that the tilting forces are taken up by the guide mεmbεr and the aεεociated thread arranged in hole 25- Fig. lβ shows a corresponding guide membεr 30 DU -t seen from above. The dashed lines 31 indicate a recεss of rectangular cross section, and the dashed lines 32 correspond tc hole 25 of Fig. 15- As ' iε clear from the figure the center lines 33 and 3 . respectively, croεε each other with an angle different from 90 . Herεby the guide member can be adjusted to thε pitch anglε of thε coil spring in relation to the thread and in thiε manner the movement of the coil spring when changing the diameter cf the εpring will be facilitatεd. Fig. 17 shows an embodiment of the device according to the presεnt invention in the form of an instrument 35 for performing surgical operations. A coil spring 6 is in contracted εtate arranged about a cylindric carrier body 7. Thiε body iε provided with a tubular central part 47 and end εections 40, 4l, which by a rotary ring 45 are rotatable relative to each other and also axially diεplaceable in relation tc the central part 47. At one end of carrier body 37 flexible coaxial cable 42 is connected to one end section 41. This coaxial cable 42 contains an cuter tubular part 42b an inner element 42a concentrically arranged εxtεnding through εnd section 4l and the central part 47 cf carrier boάy 37 all the way up to the second end section 40, to which it is securely attached. At the free cuter end of coaxial cable 42 therε are arranged neb members -3, 44, of which one nob member 4 is connected to the outer part 42b of the coaxial cable, whereas thε ether nob member 44 is connected to the Inner element 42a of the coaxial cable. ø&D ORIGINAL One end 38 of coil εpring 36 can bε clamped in a slit 46 arranged between the central part 47 of thε carriεr body and thε εnd sεction 40 by thε axial dis¬ placement of the latter. The other end 39 of coil spring 36 is in a corresponding manner clampable in a slit 48 betwεen end section 4l and rotary ring 45, alεc thiε in viεw of the axial displacement of end section 41. Thε clamping of ends 38, 39 of coil spring 36 in slits 46 and 48, rεspectively, aε well aε the releaεe of the endε from the εlits can be provided by axial displacement of the inner element 49 of the ccaxial cable 42 by manoeuvring nob member 44 which also operates fcr providing the axial displacement. Rotating both ends 38, 39 of coil spring 36 in relation tc each other in accordance with the principle illustrated in Figs. 1-3 can be providεd by rotating nob members 4 , 44 relativε to each other. In thε instrument shown in Fig. 17 a central through-going passage 49 is arranged by means of which contrast liquid, other instrumentε for medicinal invεεtigation can bε inεerted into thε blood vessel. The function of the devicε shown is briefly aε follows. In the εtatε shown in Fig. 17. i.e. with coil spring 36 contracted, carrier body 37 with coil spring 36 attached in the respective slitε 46, 48 iε inεerted through an easily accessible location on the blood vessel in question and fast en to the defective position of -larger diameter. The expansion of coil εpring 36 iε provided by rotating nob means 43, 44 in relation tc each other. After coil εpring 36 has expanded tc tenεicn-lεss statε or essentially tension-less εtate itε εn ε 36, 39 arε releaεεd bi ¬ axial displacement of nob members 4 . 44 relative to each other so as to widen εlits 46, 48. In thiε manner ends 38, 39 of the coil εpring 6 arε rεleased, wherε- after coaxial cable 42 and support bodj-- 37 attached thereto can be removed * from the blood vessel. In Fig. l8 therε is shown an alternative εrabodi- εnt of the device according to the invention in the form of an instrument generally designated 1 ϊOr carrying out surgical operations. The device iε based upon thε spring principle in accordance with that shown in Fig. and in connection to the embodiment shown in Figs. 13A and 133. In Fig. 18 spring 52 is shown in contracted state. The axially extending support means 53 of the spring iε sεcurely attached to one end 5 of εpring 52, whereas the spring at its other end Is movable through a guide member 55 arranged on support member 53• Spring 52 and εupport member 53 are attachεd to a cylinάric elastic and hollow body 6 by ' means of latches not shown In the figure, one at each end of support means 53- The latches can be releaεed from the endε of εupport member 53 o means of for example a wire for each extending within hollow body and a coaxial cable 57 connected thereto and can in this manner be controlled from the outside. Between coaxial cable 57 and the end 55 of εupport member 53 the εpring iε wound about carrier body 56 with relatively eloεε windingε 58. Thε end 62 of εpring 52 ' adjacent to thε coaxial cable iε releaεably connected tc a sleeve 59- The sleeve surrounds the C3 ** llnder carrier body 56 and can be rotated and axially moved by means of a flexible tube which iε concentrically arranged in thε coaxial cablε 57- Tr.e expansion cf spring is provided by rctatlng sleeve 59- the spring exceεs εtcrεd adjacent to the sleeve expanding simultaneously with εpring 52 moving through guide means 55. During the expansion the sleeve Is slowly brought forward by the axial movement of the flexible tube. BADORIGINAL The total length of spring 2 has been adjusted in advance so that when the expansion is interrupted by the surrounding inner walls of the blood vessεl only a minor length of spring material is found outside guide member 55. When the surgeon haε checked that thε spring has taken its correct position spring 2 with carrier member 53 will be released b 7 releasing the said latches and the attachment of end 60. If in connection to applying the instrument it is found that the selεcted spring length is not εuitable but need to be changed thiε can be done by contracting thε spring before releasing latches and the end 60 by rotating sleeve 59 in the opposite direction, whereupon the instrument can be removed and spring be replacεd by another spring of suitable total length. The excεsε 53 of thε εpring which has bεεn exteriorly wound about body 5 in close windings may, according to another embodiment of the invention, be interiorly εtored in a sleeve and by means of suitable members be fed out from said sleeve through guide mεmbεr 55 (Fi - 18). This embodiment iε shown in Figs. 19 and 20 in axial and radial section, reερectivεl3 r . According to this embodiment a feed cylinder 63 is eccentrically mounted in a C3 ** lindric housing 6l. In housing 6l cams 66 are cut to form an interior trapεzoid thread 67- Fεed cylinder 63 is exteriorly coverεd by a rubber layer 64. When using the device the band material 72 of the coil spring lies within trapezoid thread 67 and thε rubbεr layer 64 arranged on the feed cylinder 63 iε in preεεing engagement against band material 72 along distance 68-69 (?-£• 20). If now feed cylinder 63 iε rotated in the direction of arrow 71 spring band 72 will be advanced cut through guide member 55 (Fig. 18) with simultaneous expansion of the εpring. In view of BAD lGI AL^JREX OMPI the fact that feed cylinder 63 having rubber layer 64 engagεs intεriorly along thε whole length of trapezoid thread 67 thε spring band 72 may be retracted back into housing 61 if feed cylinder 63 is rotated in the opposite direction, thε coil spring being subjected to contraction. The advantage of interior εtorage of εxceεε of εpring matεrial in a caεing in accordance with FIgε. 19 and 20 is significant. Thus, the contraction or expansion of the coil spring does not cause any diεturbance cr irritation of surrounding tissue in view of the fact that the spring excess is enclosed in a casing. I-_orecver, by means of the feeding arrangement and the guiding of the spring through a terminal guide membεr 55 (Fig- l8) a vεry even and controlled expansion of the spring along all of its length will be obtained. This latter fact means that the implanta¬ tion of the spring will be significant! ** facilitated. In certain cases it may be desirable to line the inner wall of a damaged blood vessel or other organ with e.g. porous artificial tissue, for example in order to obstruct a fracture in the blood veεεel. Alεo such lining can be provided using the device according to the present invention. Fig. 21 shows diagrammatical!}-- in a cross section a spring 21 in accordance with Fig. 13A in contracted state with εupport member 23A. A pc-rcuε tiεεuε in the form of a eylindrie εtocking 73 ε arranged round the spring and attached tc carrier member 23A by means cf fine threads 24. The tiεεue is overlappingly folded double at folds 75 and 6 so aε tc elcεely encloεε εpring 21 in contracted εtate. Stocking 73 is held in this pcεltion by means of an axial!}-- extending thin metal wire 77 arranged in fold 75- After εpring 21 with surrounding stocking 73 has bεen inserted to the damaged site by means of an instrument, for example according to Fig. 17, metal wirε 77 is rεmoved whereupon εpring 21 is brought to expand. During the expansion of spring 21 εtocking 73 will be opened out and will, finally, be brought to firm engagement againεt thε inner side of the damaged site of for exa plε a blood vessel. As an alternative to the embodiment deεcribεd above thε cylindrical εtocking may, of courεe, be made of a strεtchable material which, in connection to the expansion cf the spring, can be stretchεd to an expanded εtate without using double folding of the material. Such material may for examplε bε a round stitched or round knitted close meshed article, for example of the tricot type. Such alternative embodiment is, of course, particularly useful at lower expansion numbers, for example in such casεs whεn the instrument with the εpring in contracted state is inεerted into a blood vessel of a relatively constant diameter but wherε nonthεless certain contraction in relation to thε inner diamεter of the blood vessel is necessary in order to avoid damages tc the inside of the blood vessεl in connection with inserting thε instrumεnt into the vessel. It should be observed that the present invention is not limited to the particular embodiments described above which only are intended tc illustrate thε invention. Thus, thε housing described in Figs. 19-20 instead of the eccentrically mounted fεεd cylinder 63 may contain any suitable feed means by which the εpring can be moved out from and into casing 6l. As conceivable alternatives there may be mentioned a concentrically arranged feed roller or a feed screw which is axially moved in connection with storing of the spring and thus after completed fεεding of thε εpring will be rotated back into housing 6l before removal of the instrument from the site of application. Moreover, the embodiment described in connection with Figs. 13A and 13B using a fixed guide member at each end of the spring for simultaneous feeding at both ends of the spring, can be designed so that the spring at its mid point iε firmly anchored to carry a member 23A. In this way two spring halves are formed, each half being associated with a casing or other storage means. In the embodiment shown in Fig. 22 the spring is made of a band-shaped material 78 which has beεn providεd with elongated openingε 79,. for example by punching. In thiε manner the εpring takes the shape of a ladder. Spring 78 which can be expanded in the same manner as thε spring of Fig. 1 shows quite good stability and the risk for tilting of the εpring in the manner shown in Fig. 10 has been eliminated. By suitable choice of band thickness and width of the step iron-like remaining partε of the band the good stability can be combined with high expansi ility from a small diameter to a large one. Springs possessing gccd stability similar to that of Fig. 22 can be manufactured in another manner than by punching openings. Thus, " there Is shewn in Fig. 23 a ladder-like εpring made frcm a round wire inεtead of from a flat band. In thiε caεe the εpring has been manufactured by initially producing a ladder by attachment of two adjacent parallel wires 8θ and 8l by means of transverse elements δ2. Tniε device may alεo be regarded to be a double spring composed of two single springs 80 and δl. As prevously mentioned, there is often a need to line the inner wall of a damaged organ with some tissue. In connection to Fig.2 there iε shown an arrangement BADORIGINAL whereby such tissue can be introduced into a damaged organ. Even if the arrangement illustrated in connection to the particular spring shown in Fig. 3 it should be noted that it is, of course, applicable to all types of coil springs. The spring of Fig. 23 is surrounded by a stocking 95 of some porous matεrial which, by mεans of stitches or thε like indicated at 97, is attached to a longitudinally extending bar or rigid wire 94, which in -turn Is ' attached to εpring 8θ, 8l at croεεing pointε β in a εuitable manner, for example by εpot welding, gluing or the like. By this arrangement the spring can act aε a graft in implantation in for example a blood vessel, and thanks to the fixation of stocking 95 to the axially extending wire 94 it is kept in place during the whole application operation so that after application in the blood vessel it wholly surroundε spring 8θ, 8l thus forming an artificial tissue in the blood vessel. Stocking 95 is suitably made of some stretchable porcuε material which can follow the spring material in the expanεion of the εpring in connection with the application at thε intended location. Thus, it can . conεiεt of any knitted cr stitched material of tricot type with a necesεary εtretchability or some type of crepe product. ne alternative is a stretchable plastic film, i.e. elastomer, fcr example cf silicon reεin. The embodiments of the springs shown in Figs. 22 and 23 may aε alternative to the embodiment just described be used aε carrierε for porous materials, for example tissue, which iε illustrated in Fig. 24. A lad εr-likε εpring 83, designed for example like the spring of Fig. 22 or 2 , is covered with BADORIGINAL f OMPI porouε material 84. In order to enable the deεirablε dεnsity betweεn the spring turns the supporting double spring has, however, been somewhat modified in that the cross stepε of the ladder, correεpcnding to elements 82 of Fig. 23, have been arranged In step position 85. In this manner the spring turns overlap each other and the desired dεnsity ca be obtained. Fig. 25 showε in enlargement an axial section through two adjacent turns " of the spring of Fig. 24. .As is seen the cross elements 82 are provided with a shoulder 86. Thε spring is covered with porous tissue 84. As is clear from Figs. 24 and 25 sealing will be . obtained even if the εpring iε subjected to axial move- mεnt. This is of Importance if it is desirable for example to use the device according to Fig. 17 to expand the spring. Since the distance between members 38 and 39 is constant thε pitch of the spring will be changed when thesε members are rotated relative to * eaeh othεr. By using the embodiment of Figs. 24 and 25 this is made possible with maintained sealing in view of "thε fact that cross elements 82 sli e in relation to each other in an axial direction. It is for example posεible to design the εpring according to Fig.- 24 so that when it is7 " eontracted state attachεd tc the device according to Fig. 17 the overlap between the turns is relatively large whereas after the expansion the overlap is relatively small. If it iε deεirable tc maintain thε same pitch in contracted as well aε expanded εtate of a εprtng, according to for example Figs. 24-25, this can be provided by modifying the device cf Fig. 17 so that members 8 and 39 are subjected to axial movement towards each other or from each other when the spring is expanded and contracted, respectively. BADORIGINAL In this manner the pitch can bε maintained relatively -constant, which may be of advantage, particularly with regard to the embodiments according to Figs. 22-25- In some casεε it can be εuitable that the porous tissue, rather than bεing attachεd on thε outside of the ladder-like devices, is designed in the form of semi-permeable seetionε cf the band-like material. Thus, in this case openings 79 of Fig. 22 arε rεplacεd by a thinning of thε band- atεrial propεr, in which thinning very fine perforations have been applied so that thε same perforated surface will be obtained. Also in thiε caεe crcεε elements 78 form the necessary rigidification. A further advantage of the device according to Fig. 24 is the fact that the porous material doeε not neceεεarily need to be elaεtic in ordεr tc participatε in thε expanεion of the εpring. Fig. 26 shows a modified design of the spring in thε devicε according to the invention. The modified spring shown in the figure generally indicated 90 is acrosε the major part of its length designed as a conventional spring of constant diameter, whereas at the upper end 91 as shown in Fig. 26 It is designed with a diminishing diameter so that the εpring 90 in - unloaded εtate haε the configuration shown in the figure. In crdεr to facilitatε thε following description of the function of the εpring the lower free end of the εpring haε beεn designated 9 whereas Its free upper end has been designated 93- In regard tc contraction or expansion of εpring 90 in connection with application at the intended location the function of thε εpring shown in Fig. 26 is the same as that of the previously described embodi¬ ments of the spring. However, in view of the fact that εpring 90 iε provided with a diminishing end 91 certain BADORIGINAL. modification of thε inεtrumεnt to be uεed for operating the εpring may be desirable. For examplε thε instrument εhown in Fig. 17 can be modified for adaptation to the εpring according to Fig. 26 by excluding end εection 40 and providing the inner element 42a at the end extεnd- ing through carriεr body 37 with a croεε groovε intended to accomodatε and hold the upper freε εnd 93 of εpring 90. Thε other εnd 92 cf εpring 90 may then in thε εamε mannεr as dεscribεd in connection to Fig. 17 be held at the other end of carrier body 37 in connection to end εection 41, whereupon in the manner previouεly deεcribed spring 9 can be contracted by rotating rotary members 4 , 44 in relation to each other. With spring 90 in contracted state it may thus be applied to the desired location within a blood vesεεl, for εxamplε Vena Cava Inferior for the purpoεε of prεvεnting lung embolia. Previouεly known filter meanε intendεd for application within blood vessels for the purpose of entrapping tromboεes are εubject to the diεadvantage that they are pεr anεntly attached In the blood vesεel by pointε or hookε or the like whereby correction of location or removal of the filter iε not poεεible. Example of εuch a device iε dεεcribεd In U.S. patεnt 3,540,431. By uεing thε device according to the preεent invention such as that illustrated in Fig. 23 these drawbacks arε, however, avoided while obtaining essential advantages, among which the following may be mentioned: 1. the spring with filter function is self-attaching by engagement againt the inner wall of the vessel without causing damages to the inner wall; BADORIGINAL "SfυfcE OM • WI 2. the position of the εpring can be corrεctεd and removal of same is poεεible; 3. the device results only in an insignificant reduction of the flow across the section of the blood vessel; 4. the application of the device is significant¬ ly simpler than that of the prior art. In ordεr to prevent clogging cf the diminishing end 91 of spring 90 by small lumps of coagulated blood a εuitable diεtance between the spring turns in the diminishing part of thε εpring is about 3 mm. By using such distancε thε passage of larger- tromboεes is avoided whereas too early clogging of the diminishing part of the spring is avoided. In connection to the embodiment of Fig. 26 and also in connection to other embodiments of the spring of the device of thε presεnt invention a spring insεrtεd and applied in for example a blood vessel can be removed in the following manner. A flexible tube of a diameter adjusted to the blood vessel is insertεd up to the εnd 9 of spring 9C or further up to its other end 93, whereupon the spring end Is grabbed in a suitable manner by means of a grip mεmbεr, whereupon the εpring can be retracted through the tube without damaging the surrounding tisεue. This procedurε can bε suitable to resort tc in case the spring haε taken a wrong position c-r haε come to a wrong location in thε bleed vessel. Fig. 27 shows an embodiment modified in relation to the de\ * lce according to Figs. 2- and 25, whereby the inner wall of a damaged organ can be lined with porous tisεue. The embodiment ' contains εpringε of the type illuεtrated in Figs. 22 and and reference numerals of the figure contain the corresponding designations as Fig. 23. Acccrding to Fig. 27 the double spring δθ-82 is covered with stocking 83 of porous tiεsue surrounding the separatε turns in thε spring along thε wholε lεngth of the spring period. The stocking 83 extends sidε-wiεe outεidε thε εpring matεrial whereby there is provided overlap inside adjacent turnε of thε spring, as is clear from Fig. 27. • A.lso in thiε case thεrε is obtained sealing if the spring is moved in an axial direction, for example if the device according to Fig. . 17 is used to expand the spring. In other reεpεctε thε device according to the invention containε the following featureε taken each per εe or in any combination, namely: a) that said other state (Fig. 2; 4) esεentially corresponds to unloaded condition of the coil spring 1; 36 b) that shaft 42a and εleeve 42b are relεaεably connεcted to coil εpring 36 c) an axially extending guide bar 23 arranged at the periphery cf thε εpring on which at least one guide member iε dlεplaeeably arranged and through which the εpring material can move tangentially in connection with the contraction or εxpanεion of thε εpring; d) fixed guide memberε 22 distributed over the said given length cf the spring and arranged at the periphery cf the εpring- on an axially extending support member 23, the εpring material 21 moving tangentially through εaid fixed guide members-in connection with thε expanεion or contraction of the spring; ε) that the εnd sections or parts thereof 40, 41 of the carrier tody 37 are axially diεplace- BADORIGINAL ablε relative to the central part 47 so that in the gaps 46, 48 between the central part 47 and the respective end sections 40, 41 the ends 38, 39 of the spring can be releasably attached; f) that at leaεt cnε section or part thereof 40, 41 is axially diεplaceable by means of a member 44 arrangεd at thε free end of the coaxial cable 42; g) an axially extending support member 23 at the circumference of the spring 21 at one end 21a of which the εpring 21 is attached and at the other end 21b of which there is providεd a fixed guide member 22a through which the spring material can move in connection with a contraction or expansion of the spring 21; h) an axially extending εupport member arrangεd at thε periphery of the εpring at both ends of which there are arranged fixed guide mεans through which thε material of the spring can move in connection with the contractional expanεion of the εpring; i) an elongated carrier body 56 about which i- '1 the εpring 5 iε arranged, a caεεette. magazine arrangεd at one end of thε carriεr body including a cylindric caεεεttε housing 6l, a feed member 6^ ~ rotatably arranged therein b which thε εpring can be moved for contraction cr expansion by rotating feed member 63 in one direction cr the other; j) that the fεεd member consists of a feεd cylinder 63 eccentrically mounted in the BAD cassette housing 61 a cylinder 63 at its periphery engaging the inside of the cassette housing 6l; k) a trapezoid thread provided on thε inside of casεεtte houεing 6l in which the εpring 52 can glide; 1) that feed cylinder 63 on itε exterior is provided with a friction coating 64 of for example rubber or plastic; m) an elongated carrier body 6 about which thε spring 52 is arranged and at one end of which one end of the spring is releaεably attached, a magazine εeetion 58 extending from the other end of carrier body surrounded by the εpring carrying at itε outer end a rotary εleeve 59 to which the other end of the εpring is releasably attached, and meanε for rotating and axially displacing rotary εleeve 59 relative to t e carrier body 56; n) that stocking 73 by εtretchability in the tissue iε adaptable to the spring diameter in connection with thε expansion of thε spring; o) that stocking 73 by overlapping folding 7 * 76 iε adaptable to the spring diamεtεr in connection with the expansion of the spring; p) that stocking 73 s attached relative to spring 21, for examplε by thread stitcheε. In the instant disclosure the term "ceil spring" refers to a helical εpring of the traditional type. However, the spring used in the device of the invention neεd not nεceεsarily have constant diameter or a constant pitch. The general configuration, however, is that of a helix. . ,' ; * BADORIGINAL Thε invention is also useful in certain kidnεy disorders, where so-called hae odialysis takes place. In this operation a needle or cannula is applied to the patient's arm εo that blood iε extracted from thε body and after purification in a dialyser returned to the body. Since dialysεs have to be repεatεd at lεast oncε a week problems arise in regard to the blood vεssεls of the patient. Thε problem haε been solved by arranging a so-called by-pass providing a permanent connection between an artery and a vein, fcr examplε in thε arm of the patient. Thiε connection may be made of fcr examplε vεεεεl proεthεεεε or a vεin taken from calves, so-called "εolkcgraft". The advantage cf using such a by-pass is the fact that the high pressure frc the artery provides for expanεion of the connecting vein making it easily accessible when inserting the cannula. Moreover, a large number of dialyseε can be made beforε εxchanging the connection. Thε connecting conduit is usually positioned bεnεath thε skin and iε attached to the artery and the vein by stitching. However, also the connections hitherto used result in cεrtain problems. When the proεthεεiε is withdrawn benεath thε skin in an operation it may be folded and blocked. After the removal of the haemodialysis cannula the connecting prosthesis must be compressed to prevent too large a loss of blood. The artificial vein may then easily collapse resulting in subsequent impaired circulation. It has also been found that so-called stenoses, i.e. contractions, will bε formed whεrε the connection iε attached to thε vein. It has new 1 been found that thε disadvantages associated with the above connecting conduits or proεtheses can be eliminated by using the device of thε invεntion by using the following procedure. A helical εpring of suitable diameter and of a BADORIGINAL/ OMPI εuitable number of turnε iε attached in an instrument in accordance with the invention, for example as illuεtrated in Fig. 17, i.e. the spring is in contracted statε. A proεtheεiε, for example a εolkograft, is attached at one end thereof to a vein of the patient by a few stitcheε. Then the device of the invention including the εpring iε Inεerted into the graft εo that the outer εnd of thε device with the correεponding end of the εpring will reach a pcεition about 2 cm inεide thε vein. Then the εpring is expanded inside the prosthesis and rεleased from thε instrument which is then withdrawn from the prosthesis. By means of a cut beneath the skin the free εnd of thε graft is transferred up to the opening of the artery and attached thereat. The arrangemεnt dεscribed above 'has beεn found to result in great advantages. 1. The graft will not collapse when implanted due to the action of the εpring. 2. Thε connecting conduit or proεthesis may safely bε ccmprεεεεd or cla pεd after removal of the cannula for reducing blood losses. The conduit immediatεly returns to full diameter in view of the action of the spring. 3- I is easy to find thε pro-sthεεis under the skin and this in turn facilitates puncturing the conduit. 4. It has been " found that -the risk for the formation of stenoses in thε vein is reduced, ϊn using the conventional technique the site of connection must be changed and moved tc another location at least once a yεar duε tc formation cf stεnoεiε. In addition to thε applicaticn of the invention as described above there are also other important areaε where the device of the invention may be used. Thus, , there are prεsεntly difficulties in performing animal tests, for example on dogs, wherε it is dεsirablε to introduce for example drugε several times a day to study the effects in long-time tests. Up to now such εxpεrimεntε havε not been feasible inter alia in view of the fact that animals are subject to rapid formation of stenoses. By using the arrangement described above tests of lengthy duration can be made on for example dogs with one single per anεnt connεction.

Claims: PATENT CLAIMS: 1. Devicε comprising a helically shaped spiral spring (1; 36; 78; 80-82) and means for bringing the spring to expand from a first state (Fig. ; 5) of a certain diameter to a second εtate (Fig. 2; 4) of largεr diameter and vice versa, characterized therεby that said means (35 > 51) are arranged to rotate the ends (38, 39) of the spring relative to each other with maintained length (L) of the spring (1; 36) so that the transition from said first state to said εecond εtate takeε placε by reducing the number of εpring turns within said length (L) and the corresponding Increase of the pitch (s) of the __pring, or to supply to a given length (L4) of the spring (1, 52) further εpring material (B) at at least one end of the said length (L4) of the spring (1) so that the transition from said first state to said εecond εtate takeε placε indεpεndent of pitch and number of spring turns within the said lεngth (L4). 2. Device according to claim 1, characterized thereby that one end (38) cf the spring (36) is attached to a shaft (42a) which is centrally arranged Inside the spring, wherεas its othεr εnd (39) is connεcted to a sleevε (42b) surrounding thε shaft (42a), whεrεby through rotation of thε shaft and/or thε sleeve relative to each other reduction cr increaεε of thε diameter of the εpring (36) iε provided. 3.. Device according to claim 1 or 2, characterized thereby that the spring material (29) as seen in axial croεs section haε a radiallj- flattened shape to reduce the risk for εpring ccllapεε. 4. Dεvicε acccrding to any preceding claim, charaeterizεd by a stocking (73) of strεtchablε tiεεuε εurrounding thε εpring intεndεd for Implantation together with the εpring. > 5. Device according to any of clai ε 1 to 4, characterized thereby that the spring material (78) is provided with radial through-rεcesseε (79) between which axial and tranεvεrεε minor sεctions remain, whereby the expansive or contractional capacity of the spring will be increased. 6. Dεvicε according to any of claims 1 to 4, characterized thereby that the spring is composed of a co-extεnsivε doublε εpiral or εpring wherein the εpiral elε entε (8θ, 8l) are connectεd by means of tangentially distributed and axially extending cross embεrs (82). 7. Dεvicε according to claim 3 . 5 or 6, charact- erized therεby that thε tranεvεrεe sections or crosε mεmbεrs (82) arε providεd with a eεntrally positionεd radially oriεntεd shouldεr (85, 86) whεrεby adjacεnt spring turns can overlap. 8. Device according to claim 7, characterized by a stocking (84) of porous tissue surrounding the individual turns of the spiral (78; 80-82) in sub¬ stantially the whole length of the spiral material. 9- Devicε according to any prεcεding claim, charactεrized thereby that the spring (90) iε designed to act as a filter after application by having at at least one end (91) thereof a diminishing diameter. 10. Device according to claim 9 . characterized thereby that the distance between the turns of thε diminishing εnd (91) of thε εpring (90) defining the flow pasεage is about 3 Em. 11. Device acccrding to claim 6 or 7, charact- εrizεd by a εtocking (83) of porous tissue surrounding thε individual turns (80, 8l) of thε spiral in the whole length of the εpiral material and extending laterally outεide the εpiral matεrial thεrεby providing ovεrlap OMPI WIFO within adjacent turns of the spiral. 12. Device acccrding to any of elaimε 1-10, characterized by an axially extending and elongatεd mεmber (94) coεxtεnsive with the pεriphεry of the spring which is attached to the spring at one location {96) , and by a stretchablε stocking (95) of porous matεrial surrounding thε spring which iε attachεd tc εaid mεmbεr (94) and which is intended to be Implanted togethεr with thε spring. 13- Dεvicε according to any prεceding claim, characterized by a cylindrical tubular carrier body (37) arranged within the coil spring (36) comprising a central part (47) and being provided with end sections (40, 4l) at the ends (58, 39) of the spring rotatable relative to each other, the ends (58, 39) of the spring (36) being eonnectεd to thε rεεpective end εections (40, 41), and means (42, 43, 44) with the help of which the said end εectionε (40, 41) can bε rotated relative to each other to expand cr to contract thε εpring (36). 1-4. Dεvice according to claim 13, characterized in that εaid means comprise coaxial members (42) connectεd to the one end section (4l), the interior element (42a) of thε said members extending through the carrier body (37) and being at the end connected to thε other εnd εection (40), rotators (43, 44) being arranged at thε outεr frεε end of the coaxial members- 15- A method for tranεluminal implantation of an intravascular proεtheslε, ccmpriεing introducing into thε vessel at one location a device according to any of the preceding claims with the spring in contracted state, tranεluminally transferring the device to another location of the vessel, expanding the spring within the vessel at said other location to bring about (^ sεlf-fixation of same, and, after relεaεing thε spring, removing the device save the εpring from the vesεel. 16. A method according to claim 15 including thε εtεp of εεlecting a εpring of a diameter in unleaded εtate εomewhat larger than the internal diameter of the vεεsel at .said other location so as to provide for an internal prεεεurε of thε εpring againεt thε innεr wallε of thε vεssεl. OMPI

Inventors: MAASS DIERK, WALLSTEN HANS IVAR, MAASS, DIERK, WALLSTEN, HANS, IVAR
Applicants: WALLSTEN HANS IVAR, WALLSTEN, HANS, IVAR
Application year: 1982
Main classification: A61F1
IPC codes: A61F2