MXPA97002257A - Implant of a - Google Patents

Abstract

The present invention relates to a porous implant, in particular for the closure of an abdominal wall, has a flexible basic structure made of a knitted fabric consisting of non-resorbable or slowly resorbable material or a combination of such materials. The knitted fabric in the basic structure is designed to stretch more than the region of the tissue intended to receive the implant below the critical force and to knit less than this region of tissue above the critical force. The critical force is under the highest load that is permissible for this tissue region. The basic structure is provided with a resorbable and synthetic stiffener material whose resorption time is less than that of the basic structure.

Description

AREA IMPLANT FIELD OF THE INVENTION The invention relates to an area implant, in particular for abdominal wall closure.

BACKGROUND OF THE INVENTION During operation in the abdominal region, it is often necessary to reinforce the abdominal wall using an implanted area implant. It is known to use for such implants networks made from non-resorbable plastics polypropylene or polyester, or from polyglactin 910 slowly resorbable (? Copolymer glycolide and lactide in the ratio 9: 1). Metallic implants are also used. The known implant networks have some disadvantages. For example, they are relatively heavy, that is, as a rule. the area weight is more than 50 g / m2 and predominately up to approximately 100 g / m2. In this way, if the implants are not resorbable, a relatively large amount of foreign substance remains permanently in the body. In terms of resistance to deformation, known implant networks are often overdisensioned, that is, they have a much higher resistance than is required from a physiological point of view. E < - The properties of the basic structure of previously known implants. combined with the construction, similar to a network, can bring as a consequence that the welfare and mobility of a patient, who is adapted with such an implant, are limited. Another disadvantage of previously known area implants is that, without being more flexible, although they fit better to the abdominal wall after the operation, then they can only be inserted with difficulty, since, for example, they bend easily. On the other hand, although a rigid implant is easy to handle, it can lead to long-term problems --- or after insertion into the abdominal wall, as already mentioned. In this way, previously known area implants are too flexible for ease of working during an operation or too rigid for a non-problem interaction with the abdominal wall into which it is inserted.

DESCRIPTION OF THE INVENTION Thus, an object of the present invention is to provide an area implant, in particular for abdominal wall closure, which can be easily worked during an operation and which exhibits a long-term elasticity behavior that is equal to + ej? where it is inserted. This object is achieved by means of an area implant, in particular for closing the abdominal wall, which has the features of claim 1. Modalities in josas derive from the dependent claims. The implanter of area according to the invention has a flexible basic structure made of a knitted fabric comprising non-resorbable material or resorbable material or a combination of said materials. If resorbable material is used, the resorption time (ie the period after which the total mass of the implant has been degraded in vivo) is at least 60 days and / or the decrease in live resistance is so slow that 30 days after implantation, the resistance to deformation is still at least 10% of the initial deformation resistance. Non-resorbable or resorbable materials are used slowly so that the basic structure is stable for a longer term and a more accurate cure result can be ensured. The term "knitted fabric" is understood in the present in the broadest sense. It also includes, for example, knitted fabrics and other mesh structures, that is, essentially all textile materials that are not pure woven fabrics. The knit fabric of the basic structure is designed to stretch more than the region of tissue intended to receive the implant below a critical force and stretch less than this region of tissue per cent of the critical force. The critical force is below the load most a + a to which this region of tissue can be subjected. The flexible basic structure thus equals smoothly with the usual movements of the fabric (e.g., of an abdominal wall) into which the area implant is inserted or sewn. In the case of small forces, or occurs during normal movements of the patient, the elasticity behavior of the system, consisting of an abdominal wall and the inserted implant, is regulated by the abdominal wall. In this way, the implant does not act as a foreign body. On the other hand, if the forces exceed the critical force, the implant absorbs the forces and thus prevents damage to the body tissue, e.g., the abdominal wall. According to the invention, the basic structure is made rigid by means of a synthetic resorbable material whose resorption time is less than. that of the basic structure and preferably is on the scale from 2 days to 200 days. As a result, the implant area is relatively firm and easy to handle during operation (for example, when it is cut to size and inserted) but then loses its inconvenient rigidity after a relatively short time in body tissue, since The synthetic material of stiffness is reabsorbed. In a preferred embodiment, the knitted fabric of the basic structure is constructed in such a way that it has deformation properties that can be quantified using a plunger press test, as set forth in claim 2.

The area weight of the basic structure is preferably less than 5Qg / m2. When suitable materials are used (see below) for an implant for abdominal wall closure of mass corresponding to a resistance can be achieved that is above the framework of physiological data given by Klinge (U. Klinge, B. Klosterhalten, U. Li berg, PP Ottmger, V. Schumpelic: Use of mesh matepals m scar r? pt? re; Change in the abdominal wall dynamics after rnesh implantation; Pster, 162nd Convention of the Lower Rhine- estphalian Surgeon's Ps., 1995). According to him, the intra-abdominal pressure is at more than 20 kPa (150 m Hg), the wall effort at the edge of a region of abdominal tissue is, at most, 16 N / cm, and the resistance to deformation of the fascia, from 20 N / cm to 30 N / cm. An implant constructed in this way is thus able to absorb all the forces that occur physiologically in a healthy abdominal wall and also offers an additional safety reserve. More stable and therefore heavier basic structures offer no additional advantage, however, they may have the disadvantage of the inconvenient stiffness mentioned at the beginning. The knitted fabric of the basic structure preferably has an approximate rectangular structure or approximate quadratic structure knitted from yarns. However, honeycomb structures or structures with approximately circular openings or other polygonal structures can also be conceived. The preferred versions of said knitted fabrics are explained in greater detail in the description of the modalities, with the help of the figures. The desired strain and strain behavior can be achieved with knitted structures of this type, ie, the basic structure is stretched more than the region of tissue intended to receive the implant, below the critical force, and less than this region. of tissue above the critical force; The critical force is below the highest peak load for this tissue region. There are several possibilities for matching the stiffness material to the basic structure. In this way, the stiffening material may have, for example, resorbable threads or thin monolaments woven into the basic structure, may have a film that is applied to one side or both sides of the basic structure, or may have a coating applied to the material of the knitted fabric. There are also conceivable combinations of these. Suitable materials for the basic structure are for example polypropylene, polyester, polyglactm 910, polylactide yarns, polyglycolide yarns, poly-p-dioxanone yarns. but also copolymers .. mixtures or combinations of said materials. Suitable stiffening materials are for example poly-p-dioxanone yarns or films, polyglactin yarns or films (ie, glycolide / lactide copolymers), polylactide yarns or films, yarns or films of other copolymers of these materials, rnonophyll materials of said materials (for example with thread thicknesses of 0.01 nm to 0.2 nm in diameter), coating waxes made of said materials, in particular polyglactm 630, and others. Mixtures of synthetic resorbable materials whose resorption time is on the desired scale can also be used for the stiffening material. If the stiffening material is of a textile nature, the result of the degradation in living strength is such that, after an implantation time typically of 2 to 50 days, the resistance to residual deformation is still approximately 10% of the strength Initial to deformation. The material of the basic structure is preferably not removed, so that the basic structure, which after all remains in the body for a long period or is permanently found after the implant, does not present any undesirable bizarre body reaction as a result of the dye. On the other hand, it may be advantageous if the stiffening material is dyed. This in fact allows a better visual check on the implant during the operation. During the reabsorption the dye disappears, so that there is no dye in the body in the long term and in this way undesirable side effects do not occur. The invention is described in greater detail below. with reference to modalities and with the help of the drawings. These show: Figure 1 is an enlarged schematic view of a first version of the flexible basic structure (variant A), amplified 25 times in part a) and 15 times in part b). Figure 2 is a schematic enlarged view (25 times) of another version of the flexible basic structure (variant B). Figure 3 is a schematic enlarged view (25 times) of another version of the flexible basic structure (variant O. Figure 4 is a schematic view (25 times) of another version of the flexible basic structure (variant D). Figure 5 is an enlarged schematic view (25 times) of another version of the flexible basic structure (variant E) Figure 6 is a schematic view of a device for carrying out plunger pressing tests Figure 7 is? n plunger force diagram - piston trajectory length, measured with the device according to figure 6, of the flexible basic structure according to variant B, compared with an implant made of polypropylene (H). Figure 8 is the stress-strain diagram of the flexible basic structure in accordance with the variant fl, in comparison with rat musculature Figure 9 is a schematic diagram (Pl-piston strength length) of piston trajectory, to explain the hysteresis behavior of the flexible basic structure. Figure 10 is a schematic enlarged view (25 times) of the flexible basic structure in accordance with variant 0 which is made rigid with a wire made of poly lacti a 910, and Figure 11 is an enlarged schematic view (FIG. 25 times) of the flexible basic structure according to variant B, which is made rigid with a resorbable coating made of polyglactin 630. Figures 1 to 5 show amplified schematic views of different versions of the knitted fabric of the structure Flexible basic implant area according to the invention. The figures are drawn based on electron microscopy photographs taken at approximately 25 times of amplification. The variant A of the knitted fabric according to FIG. 1 has an approximate quadratic structure, the length of the transverse piece is approximately 3 mm in each case. The variant B of the knitted fabric according to Figure 2 also has an approximate quadratic structure. However, the length of the crosspiece is larger here and is approximately 5 nm. The variant C of the knitted fabric, shown in figure 3, has openings or pores dimensioned differently, the area of the large pores are larger than 0.5 rnm2 and that of the smaller pores is smaller than 0.5 rnm2. The D and E variants of the knitted fabric shown in Figures 4 and 5 have other structures. It is easily recognizable from FIGS. 1 to 5 that most pores are greater than 0.5 mm2. In this way, after implantation, the flexible basic structure of the area implant can grow through the tissue in a satisfactory manner, which leads to secure attachment in the patient's body and a reliable absorption of forces by means of the implant. yes? DRo i Data for five flexible basic structures according to the invention (variants A to E) and for a conventional implant network (H) made of polypropylene (polypr.) Variants Material Polipr. Polypr. Polypr. Polypr. Polypr. Polypr. Multi-multifiber filament ultifi- multifi- onofil- lamento lamento lamento lamento lamento lamento Strand systems 3 3 3 3 3 1 Number of yarns per c-m (longitudinal) 220 220 160 186 212 62 Number of beads per cm (transverse) 52 38 57 64 72 46 Thread fineness in tex (g / 1000 m) 6.7 6.7 6.7 6.7 6.7 20.6 Pore size (approx.) > 0.5 mn.2 (.raí.2) 3 x 3 4 1.3 x 1.3 2 x 3.3 1.3 x 3. .3 Proportion of peres () 93 95 83.5 Thickness (mm) 0.41 0.4 0.7 Area weight (g / m 2) 26.8 20.1 31.4 36.2 40 109 Sewing start force per an (longitudinal) (N / cm) 17.5 13.5 20.1 20.7 23 57 Sewing start strength per cm (transverse) (N / cm) 22.7 22.4 26.3 31.7 36.1 75 Pressing test with plunger (similar to DIN 54307) Fmax (N) 464 415 460 488 625 2370 Plunger path length at f-nax (mm) 44.5 44.1 40.4 40.6 44.8 44.7 Straightforward (N / c) 17.7 16.1 18.8 19.9 23.8 90.0 Deformation (%) 34.5 33.9 28.6 28.9 34.9 34.1 Elongation at break (%) 39.5 39.1 35.8 36.0 39.7 39.7 Tape tension test Resistance to deformation (longitudinal) (N / c) 33 25 33 37 45 150 Elongation at break (longitudinal) (%) 37.9 28.2 25.2 49.5 40.3 80.4 The data for the individual variants fl to E of the flexible basic structure of the inventive implant according to the invention are given in Table 1. for comparison, the corresponding data for a conventional implant network. All fl a E variants are knitted from multi-filaments of polypropylene, using three-strand systems. The conventional implant network consists of polypropylene rnonofilament, using a one-strand system. Table 1 shows the number of courses per centimeter, the number of ridges per centimeter, the fineness of the yarn, the pore dimensions larger than 0.5 mm2, the proportion of pores (in relation to the total area of the knitted fabric or of the conventional implant network) and the thickness. Compared with the conventional implant network, the R and B variants have a larger proportion of pores and a smaller thickness. As Table 1 also shows, variants A to E have a relatively low area weight, which in all cases is below 50 g / m2, and thus is clearly smaller than that of the implant network. conventional. For variants fl a E, the sewing start force per centimeter of seam length, measured along and through the knitted fabric or the conventional implant network, is like a ruler over 16 N / cm, the value cited by Klmge for the maximum wall stress at the edge of a region of abdominal tissue.

The stress-strain behavior of knitted fabrics or the conventional implant network can best be described when using a plunger pressing test related to DIN 54307. In the textile industry, the material properties relative to the area are measured with said plunger pressing tests. Figure 6 shows a schematic view of a device for carrying out plunger pressing tests. A semi-infectious piston 1, which is connected to a rod 2, moves in the direction of the arrow, that is, along the axis of symmetry. A sample 5 of the knitted fabric that is worn, or of a conventional implant network, is held between an upper ring and a lower ring 4. When the plunger 1 advances in a downward direction, it pushes the sample 5 in one direction falling. The greater the deformation of the sample 5, the greater will be the force F exerted on the plunger 1 by the sample 5. This measures the force F and the length of the trajectory of the piston s, which is a measure of the deformation from sample 5, where s = 0 when the lowest point of piston 1 is located in the plane of sample 5. With the device used for piston pressing tests, the radius of the piston is 50 rnm. The internal radius of the upper ring 3 and the lower ring 4 is 56.4 mm, so that the effective surface area of the sample 5 is 100 crn2. Table 1 gives the maximum force Fm «? applied during the plunger pressing test for the fl a E variants and for the conventional implant network, where the first sample damage occurs, (in the middle region of the sample), and the stroke length of the plunger associated Sm * x. From this, the effort called rCOntact can be calculated. corresponding to the so-called wall stress in N / cm. -T the sample, the contact effort occurs along the circular line where, in the case of the trajectory length of the smax plunger. the region of the sample supports the plunger that passes in the region of the edge of the sample that does not touch the plunger d straightly and extends to rings 3, 4. fl this effort, the deformation given in table 1 that comes horn arises result of the change in length in the sample measured in the direction of the periphery, relative to the corresponding peripheral length of the sample not deformed. From the test data, it is also possible to calculate the elongation at break, also given in Table 1, which is higher than the deformation since the sample in the plunger-pressing test is deformed, not in contact. but in the middle region where it is more stretched than in rCOntacto. It is clear from Table 1 that for all variants of fl a E, the stress at rCOntact is greater than or equal to 16 N / crn, that is, at least as great as the maximum wall stress on the board of a region of abdominal tissue (16 N / cm) cited by Klinge. The much higher value in the case of the conventional implant network is physiologically unnecessary. Table 1 also shows the results of an attraction test on a strip carried out on samples of the fl a E variants and the conventional implant network. For this, the tearing force per centimeter of width of the sample (resistance to tearing) in the direction of the sample and the elongation at break is determined. However, when taking into account that the values can be severely distorted by the test (contraction when stretching) making the plunger pressing test more informative. For the E fl variants of the knitted fabric, the tear strengths are in the range of 25 to 45 N / cm and are therefore at least as large as the tearing strength of the belts cited by Klmge (20). at 30 N / cm). The much higher tear resistance of the conventional implant network is again not necessary. Figure 7 shows a complete diagram of plunger force with respect to plunger trajectory length which is determined using a piston pressing test, for the cuff fabric of variant B compared to the conventional implant network made of polypropylene (H). The curve for variant B ends with the values Fmß? and sma made of polypropylene F - 500 N. The curve for variant D ends in the values for Fm4_? and sMax given in Table 1 while the curve for the conventional implant network is not shown completely, but stops at F = 500 N. It is clear that, for the implant of the invention as for variant B the F force of the plunger is small even with the relatively large piston path lengths. Only with larger values of s does the curve ascend sharply. With the conventional implant network, the force F of the plunger is already large with mean s lengths of plunger trajectory. The diagrams of the plunger force can be converted with respect to the trajectory length of the plunger as in figure 7 in force-length change diagrams or in stress-strain diagrams. In the case of the latter, the effort must be understood as the force per centimeter of the width of the sample. In addition, the change in length of the sample is related to the total length of the sample (before deformation) and is therefore independent of the total length of the sample itself. Figure 8 shows such a deformation-strength diagram of the flexible basic structure according to the variant fl, as a result of the piston pressing test. An effort-strain diagram was shown that was determined using rat musculature that was not obtained, however, by means of a plunger pressing test, which was not possible to perform with rat musculature for the required sample size. , but based on the tensile test of the strip on a sample strip about 1 cm wide. Measures were taken on the musculature of rat tornadoes in the thickness of the musculature that corresponds approximately to that of the human abdominal wall, in which the extension in the case of any biological sample may be correspondingly large. A narrow strip of the sample contracts in the tensile test, which leads to a much larger elongation with the tensile force given by strip width (stress) than when elongation takes place simultaneously in vain spatial directions, such as during the plunger pressing test. The curve for the rat musculature can not therefore be compared directly with the stress-strain diagram obtained in the reactor pressing test for the flexible basic structure according to the variant fl. For this reason, another stress-strain diagram is shown for the flexible basic structure according to the variant ñ which, as with the rat musculature, was determined using a tensile test of the strip, using a sample strip of cm wide. Even at a 100% elongation, the sample had not yet been torn, which is not inconsistent with the elongation at break given in Table 1 for the tensile test of the strip, because the values in Table 1 apply to the strips with larger width. In order to achieve an elongation of up to about 78%, the forces required for the vanishing fl are smaller than for the rat musculature, and for elongation of less than 50%, even smaller. This was it means that a knitted fabric according to the variant fl implanted in the muscle is stretched with it during the usual movements, without appreciable forces being necessary for this. Therefore, the implant does not have an inconvenient effect. However, if in the case of extreme loads the forces that arise approach the highest load which is permissible for the region of the tissue in which the implant is inserted (corresponding to Figure 8) to approximately 18 M / crn), the knitted fabric of the basic structure undergoes a less pronounced posterior stretch than the fabric, so that the knitted fabric of the basic structure is capable of absorbing the forces. The transition in the two elongation and stretching regions takes place with a critical force that results from the point of intersection of the curves in Figure 8. The critical force defined in this way must be below the highest load that is permissible for the tissue region. The fact that in Figure B the critical force and the highest load that is permissible for the tissue region (to be more precise, the corresponding stresses) < -, they are approximately of the same magnitude due to the tests with rat musculature that are difficult to carry out. The objective of Figure 8 is only to illustrate the two described regions of elongation. Quantitative measurements on basic and flexible structures are best carried out using piston pressing tests, and for example the Klmge data for tissue can be consulted, see above. Table 2 shows the piston forces F measured in the piston pressing test as a function of the piston trajectory length s of variants 0 to E, ie the values are shown graphically in figure 7 for the vanishing B For comparison, the values for the conventional implant network made of polypropylene (H) according to Table 1 and for another conventional implant network made of polyester (ri) are also listed. The data for Fma and for the path length of the plunger in F > ? are taken from Box 1. In the plunger pressing test, the initial damage to the sample investigated takes place in Fmax.

TABLE 2 Force F of the plunger measured in the piston pressing test related to DIN 54307 as a portion of the piston trajectory length s, and Fm *? (in N) and s (Fmax) (in rnm) for 5 flexible basic structures according to the invention (variants fl a E) and for two conventional implant networks made of propylene (H) and polyester.

A B C D? H s [m] F [N] F [N] F [N] F [N] F [N] F [N] F [N] < 10 < 10 < 10 < 10 < 10 apro approves 50 approx.15 20 apcac. 10 apcao. 20 «aproe .. I G c-pra-c. 35 aproo 1 5 approx- 30 approx. 35 ap? X? . 30 ap ?? . 0 aproo. 0 aproo 85 aproo. 300 approx. 70 approx. 70 aproe. 75 apreso • 80 aproo. 80 aprao idOaprao - 600 approx- 30 ^ cax-- 130 aproe. 150 aproo. 170 to roolo aproo 280 ---. «-..-.« - _- .., ---------- ==. = -, -. ========= ========================== ============================ * "lUX 464 420 460 490 630 460 2370 S (F ".) 45 44 40 41 45 37 45 As already seen, F ax is much larger than the conventional implant network made of polypropylene than for the F to E. Fmax variants for the conventional network of implants made of polyester is of the same order of magnitude as for the variants f To E. However, for piston path lengths of up to 30 mm listed in Table 2, the plunger force for variants 0 to E is much smaller than for the conventional implant network made of polyester, which once again illustrates the superiority of the implant according to the invention. Thus, the knitted fabric of the basic structure of the implant according to the invention and conventional implant networks show a hysteresis behavior that can be determined in the plunger pressing test. The diagram of the force of the piston with respect to the trajectory length of the piston in figure 9 shows schematically, as in the case of a new sample, the force F of the plunger, starting from the length s = 0 of the plunger path, increases to a value Fo which is defined here as the value of the plunger force at a length of trajectory of the plunger of 20 mm. If the plunger is removed, the plunger force then returns to 0 at a Plunger path length Si. Table 3 compares the Fo force and plunger trajectory length during a plunger pressing test (n = 1) and after 5,000 plunger pressing tests (n = 5,000) for a conventional implant network made of polyglactm 910, conventional implant network made of polypropylene and the knitted fabric of the basic structure according to vanishing B. In order to ensure a secure support of the sample on the plunger, force was not returned to zero in the pressing tests of the plunger (as in Figure 9), but operated at a residual force of 0.5 N. It is evident from Table 3 that variant B of the flexible basic structure of the implant according to the invention offers a resistance? ? clearly lower to the alternating load, which is to simulate the movement of an abdominal wall, than conventional implant networks achieve.

TABLE 3 Histensis behavior of different implants after n alternating loads, measured in the plunger pressing test at a plunger trajectory length of between 0 and 20 rnm and a residual plunger force of 0.5 N; see text Implant n = 1 n = 5000 Fo CN] Si Crnm] Fo CN] Si [rnm] Conventional network approx. 150 approx. 8 approx. 114 approx. fifteen . 5 of implant e made of pol yglactin 910, of rnalla coarse Conventional network approx. 240 approx. 4 approx. 164 approx. 12.5 of implant made of polypropylene Basic structure approx. 45 approx. 7.5 approx 30 approx. 14.2 according to the invention, variant B Figure 10 shows an enlarged schematic view of the flexible basic structure conforming to vanishing A, to which a multi-filament strand made of polyglactm 910 is woven to pgidize. Shown in the figure 11 is an enlarged schematic view of the flexible basic structure according to variant B which is provided with a polyglactin 630 coating. Polyglactin 630 is a copolymer of glycolide and lactide in the 6: 3 ratio and, exactly like polyglactin 910, It is resorbable. The flexible basic structure is stiffened by the strand woven inwardly or by the lining, as a result of which the handling of the implant according to the invention during use is greatly improved, in particular during operation. Since the stiffening material is resorbable, the rigidity of the implant in the patient's body decreases with time, until the implant has reached the properties of the basic structure with its favorable stress / strain behavior, as explained above. Table 4 compares the flexural strength of the knitted fabric according to variant A (figure 1), of the knitted fabric according to variant B (figure 2), of the knitted fabric according to the variant A with strand stiffener (figure 10), knitted fabric according to variant B with stiffener coating (figure 11) and a conventional implant network made of polypropylene. The aforementioned flexural strengths were determined in a 3-point bending test with the support 15 nm to part and sample width of 15 nm. The conventional implant, estimated as good by users in terms of handling, has a flexural strength of approximately 0.15 to 0.20 N / mrn. The flexural strength of knitted and stiffened fabrics are clearly higher than the original basic structures and are between approximately 0.05 and 0.42 N / mm. The last values are still much higher than that of the previously known implant network.

CUODRO 4 Flexion resistance of different implants, determined by comparative measurement in the three-point flexion test with the supports 15 mrn per part and a sample width of 15 rnrn Implant Bending strength CN / mrn] Basic structure approx. 0.03 according to the invention, variant A.

Basic structure approx. 0. 01 5 according to the invention, variant b Basic structure approx. 0.05 according to the invention, vanante 0, pgid by a strand x 80 den) made of polyglactm 910 Basic structure approx. 0.42 according to the invention, variant B, stiffened by a coating made of polyglactin 630 Conventional network of approx. 0.15 to 0.2 implant made of polypropylene The initial rigidity in the implant per area according to the invention can be varied within wide limits by means of the type, quantity and structure of the resorbable stiffener material that is applied or incorporated.

Claims (16)

1. NOVELTY OF THE INVENTION CLAIMS 1.- A porous implant, in particular for the closure of an abdominal wall, with a flexible basic structure made of a knitted fabric consisting of non-resorbable material or resorbable material, which has a long time of resorption for at least 60 days and / or a decrease m alive in resistance that leads to a tear resistance that remains after 30 days which is at least 10% of the initial tear strength, or a combination of such materials, further characterized in that the knit fabric of the basic structure is designed to stretch more than the region of tissue intended to receive the implant under a critical force and stretch less than this region of tissue above the critical force, the force being critical under the highest permissible load for this tissue region, and with a synthetic resorbable material, which pgidizes the basic structure, whose resorption time is less than that of the basic structure.
2. 2. An implant per area according to claim 1, further characterized in that the knitted fabric of the basic structure is constructed in such a way that a plunger pressing test carried out on an implant of 100 crn2 in area with plungers half-sféncoe of 50 rn in radius will produce plunger force diagram with respect to the trajectory length of the plunger that corresponds to a force-length change diagram, in which the plunger force is at most 15 N up to the length of piston trajectory of 10 rnm, less than 50 N to piston trajectory length of 20 rnm, and less than 200 N to plunger trajectory length of 30 rnm, and in which plunger force for lengths The piston path length of more than 30 mm progressively increases to the value of between 200 N and 1000 N at the plunger path length of 38 mrn.
3. 3. The implant per area according to claim 1 or 2, further characterized in that the resorption time of the stiffening material is from 2 days to 200 days.
4. 4. An implant per area according to claim 1 or 3, further characterized in that the weight per area of the basic structure is less than 50 g / rn2.
5. 5. An implant per area according to one of claims 1 to 4, further characterized in that the knitted fabric has a structure woven with the strands.
6. 6. An implant per area according to one of claims 1 to 4, further characterized in that the knitted fabric has a structure as shown in one of Figures 1 to 5.
7. 7.- One implant per area in accordance with One of the preceding claims, further characterized in that the knitted fabric has meshes with an interior width in the range of 1 mm to 8 mrn.
8. 8. An implant per area according to one of the preceding claims, further characterized in that the stiffening material has resorbable strands, preferably rnonofilarnentos and / or multi filaments, knitted to form the basic structure.
9. 9. An implant per area according to one of the preceding claims, characterized in that the stiffening material has a film that is applied to one side or both sides of the basic structure.
10. 10. An implant per area according to one of the preceding claims, characterized in that the stiffening material has a coating applied to the material of the knitted fabric.
11. 11. An implant per area according to claim 10, characterized in that the coating consists of polyglactin 630.
12. 12. An implant per area according to one of the preceding claims, characterized in that the stiffening material consists of a material that is selects from the following group of materials: polymers based on caprolactone, polyglycolide, polylactide, poly-p-dioxanone, copolymers of lactide / glycolide, copolymers of lactide / caprolactone, glycolide / caprolactone copolymers, glycolide / poly-p-dioxanone copolymers, glycolide / poly-p-dioxonanone / lactide copolymers, other copolymers of the listed materials.
13. 13. An implant per area according to one of the preceding claims, further characterized in that the material of the basic structure consists of polypropylene and / or polyester.
14. 14. An implant per area according to one of the preceding claims, further characterized in that the material of the basic structure consists of a material that is selected from the group of the following materials: polylactide, polyglycolide, lactide / glycol copolymers Liquid, preferably polyglactin 910, poly-p-dioxanone.
15. 15. The implant per area according to one of the preceding claims, further characterized in that the material of the basic structure is not stained.
16. 16. An implant per area according to one of the preceding claims, further characterized by staining stiffener material. RESUHEN OF THE INVENTION An implant per area, in particular for closing an abdominal wall, has a flexible basic structure made of a knitted fabric consisting of non-resorbable or slowly resorbable material or a combination of such materials. The knitted fabric in the basic structure is designed to stretch more than the region of tissue intended to receive the implant below the critical force and stretch less than this region of tissue above the critical force. The critical force is below the highest load that is permissible for this tissue region. The basic structure is provided with a resorbable and synthetic stiffener material whose resorption time is less than that of the basic structure. EA / GC / lpm * ycl * rnvs * lss P97 / 257