ES2206545T3 - ADJUSTABLE MEMBRANE BALL MANUFACTURED OF POLYETERETERCETONE. - Google Patents

Abstract

A balloon element for use in a catheter has a multi-layered single-walled structure and a compliance characteristic exhibiting a first, non-compliant region at low operating pressures and a secondary compliant region at higher operating pressures. The properties of the balloon element permit it to serve for both dilatation of bodily vessels and stent delivery and implantation. A method of manufacturing the balloon element involves extrusion of a tube of material, such as PEEK, which serves as an inner wall layer of the finished balloon element and provides the desired strength and compliance characteristics of the balloon element, and a post-extrusion over the first tube, which provides an outer wall layer in the finished balloon element imparting abrasion resistance and other desirable mechanical properties.

Description

Adjustable membrane balloon made of polyether ether ketone

Field of the Invention

This invention relates generally to catheters. balloon and catheter assemblies that have a balloon element inflatable More particularly, this invention relates to balloon catheter elements with a single multilayer wall that have exclusive properties that allow them to serve both for dilation of a vessel as for the application and implantation of a stent

Background of the invention

The use of balloon catheters for the high pressure dilation of occluded body vessels, such as arteries and the like. Coronary balloon angioplasty, for example, it is used as an alternative to coronary surgery open heart bypass. This technique typically consists of introduce a dilatation catheter through the vascular system, with an inflatable dilator (balloon) at its distant end, to a position inside a coronary artery that has a stenotic lesion Then the ball is placed so that Cover the lesion. An inflator fluid is then introduced, normally a liquid, by the proximal end of the catheter to inflate the balloon at a high and predetermined pressure, thereby the lesion is compressed against the vessel wall and the free circulation through the blood vessel that was occluded. The balloon is then deflated and the catheter is removed. The inflator fluid is usually applied at relatively pressures high, typically between six and twelve atmospheres approximately.

Occasionally, balloon angioplasty fails to Short or long term. That is, it is possible that the vessels bloodshed abruptly shortly after being performed the procedure, or several gradual restenosis may occur months later.

To counteract the tendency of the vessel blood to be occluded again after an angioplasty by balloon, implantable internal prostheses have appeared, commonly called grafts or stents, as a means to maintain the free circulation in a long-term blood vessel. Saying simply, a stent works as a permanent support for structurally support the blood vessel wall and with it keep the passage through the coronary lumen free.

Although the present invention is not directed to own systems for stent placement, it is possible that a brief description of the operation of these systems help Understand the invention

In a typical procedure of implantation of a stent, implantation is performed immediately after a balloon angioplasty. Angioplastic dilation of the lesion produces a residual lumen large enough to receive a dilatation catheter with a balloon that carries a stent and a sheath of placement surrounding the catheter and passing through a outer guide catheter. The device and the procedures used to place an arterial stent are therefore similar in many aspects to those used in the procedure of angioplasty itself.

Typically, after an angioplasty, it is left placed an outer guide catheter once removed and discarded angioplasty catheter with its deflated balloon. Then can a stent placement system introduced through the catheter guide to a position in which the distant end of it is substantially located at the height of the distant end of the guide catheter and immediately next to it, that is, waters above the previously dilated lesion.

Once properly placed with respect to the guide catheter, the stent placement system is extended from the distant end of the guide catheter until the stent covers the previously dilated lesion. It is then removed until inside the catheter guides a placement sleeve, which can slide with respect to the placement catheter, balloon and stent, in order to expose the balloon and stent. TO a fluid is then introduced into the placement catheter pressure that dilates the balloon and the corresponding stent up to sufficient diameter to exceed the elastic limit of the stent. In this way the stent is embedded in the wall of the blood vessel As a permanent support. Then, typically, it deflates and is remove the balloon, along with the placement catheter and catheter guide, leaving the stent dilated and the lumen open.

Generally, a certain balloon catheter only You can perform one of the two functions. Or else the balloon catheter is suitable for dilation, as in angioplasty, Valvuloplasty or urological use, or is suitable as a system of stent placement So far, the materials and constructions of these dilatable balloon catheters have failed Provide a reliable dual function catheter. Typically, known catheters are not able to perform both functions acceptably or optimally. Therefore exists an advantage for a balloon catheter that can be used at a inflation pressure both low and high for angioplasty and placement of stents, and at higher pressures and with little deformability to effect greater dilation and implant the stent in some stages after placement.

Balls of the type used in catheters they are usually described by means of their dilation characteristic, expressed numerically as the tenths of a millimeter that dilates the ball from its initial diameter (called "low pressure ") each time an additional atmosphere is applied. graph of the diameter of the balloon versus the inflation pressure is called deformability curve or expansion characteristic of said ball. A ball that suffers a relatively large increase in diameter great for a certain pressure increase is said to be very deformable, which has a "high deformability" curve, or in general that is a deformable ball. If, on the contrary, a ball presents a relatively small diameter increase for a determined pressure increase, it is said to have a curve of low deformability, or that is "undeformable". Usually, it can be expected that the non-deformable balls increase their diameter a maximum of five percent (5%) over the nominal diameter initial in response to an increase in pressure to the value operating maximum Moreover, the high balls deformability typically increase between fifteen and forty percent (15-40%) within its margin of functioning.

Those skilled in the art will appreciate that a undeformable ball, when inflated to its diameter dilation, is very hard and rigid, and is able to apply a high local strength to break hard injuries (such as calcified atheromas) without the undesirable risk of injuring the adjacent anatomical structures.

Therefore, it is a general object of the invention provide a new and more useful balloon catheter and the procedures to manufacture and use it. More specifically, It is an object of the invention to provide a balloon catheter, whose features allow a doctor to carry out a procedure initial consisting of a dilation, such as an angioplasty, and then another two-stage procedure, such as the placement of a device, such as a stent, within a body lumen followed by high pressure dilation, post placement, to permanently implant the stent inside the lumen and with a desired diameter. Angioplasty It may consist of a two-stage procedure, composed of an initial rupture of a hard lesion, effected within the non-deformable margin of the ball, followed by a dilation of the lumen made within the deformable margin of the ball.

It is another object of the invention to provide a balloon catheter made of a material that not only has a "soft" touch inside the body, but also be adequately resistant to blowouts and perforations.

It is another object of the invention to provide a exclusive procedure and a combination of materials to form a balloon catheter

It is another object of the invention to provide a balloon catheter, whose material and structure allow the doctor place the stent on the catheter and use the combination of stent and catheter attached to also perform a placement of the stent after dilation.

Summary of the Invention

In one aspect of the invention a procedure to form a multilayer expandable balloon to be used with a medical catheter as set forth in the claim 9. In another aspect of the invention there is provided a multi-layer balloon as set forth in claim one.

Thus, the invention provides a balloon that can be dilated indeformably using pressures relatively low for procedures such as stages initials of an angioplasty or the initial placement of a stent. TO  then the ball can be inflated to pressures much more elevated to, as the case may be, continue to dilate the lumen, or implant a stent

As described below with greater detail, the balloon element according to the invention is provided with a soft, and more easily distensible outer layer, which provides the final balloon element with a desirable resistance to perforation and abrasion, as well as a soft "touch" inside of the body. The outer layer preferably has little or no effect on balloon dilation characteristics, but can be applied in such a way that it provides the ball with a "memory in the way "that helps the ball return to its original geometry cross section folded when the balloon is deflated during its use or after it.

There are previous proposals for balloon catheters intended for angioplasty, and that have characteristics of nonlinear dilation, but none of them are considered provides the versatility and relative simplicity of the present invention. For example, U.S. Patents No. 5,348,358, granted on September 20, 1994 to Wang and others, and No. 5,447,497, issued on September 5, 1995 to Sogard et al., both describe balloon catheters that are intended to be deformable when they expand for the first time (at inflation pressures relatively low), after which they become undeformable. The last patent also describes, as an alternative embodiment, a balloon catheter that has a ball inside another, and says it can provide a characteristic of discontinuous deformability and not linear, so that at the beginning the double ball has a undeformable characteristic, and then, when subjected to a sufficient internal pressure to burst one of the two balls, has a deformable characteristic provided by the surviving ball. With this provision, and as suggested, the internal balloon can be manufactured with a nominal diameter such that it is deformable during initial inflation until the rupture of the inner ball, after which the pressure on the ball It is said that the subsequent inflation of the ball intact exterior has an undeformable characteristic.

Layered balloon catheters are also described multiple in WO 95/09667 and US-A-5,290,306.

The balloon element of the present invention can greatly simplify surgical procedures in which is used. More particularly, it will be appreciated that when a balloon according to the invention is used, it is not necessary to replace the ball element by another element of different diameter if the first inflation of the item does not return the freedom of desired step. It is also not necessary to replace the ball element to implant the stent after placement. There are others Unexpected advantages arising from the novel construction of the present ball. The use of a balloon element characterized by high tensile strength and low deformability at relatively low inflation pressures allows precise adjustment and predictable dilatation diameter during placement of a stent, while using the same ball element in the margin of high deformability pressures allows the doctor to dilate Easily place the stent to give it its final diameter.

Brief description of the drawings

Figure 1 is a sectioned longitudinal view. showing a part of a balloon catheter, with a balloon element dilator according to the present invention.

Figure 2 is a side elevation view of a deflated balloon element of the present invention with a stent attached to it;

Figure 3 is a side elevation view of the balloon of the present invention dilated to apply and place a stent inside a body cavity;

Figure 4 is a side elevation view of the present invention expanded to increase stent size in the cavity;

Figure 5 is a graph representing, of idealized form, the expansion characteristics of an element ball according to the invention; Y

Figure 6 is a graph that represents the dilatation characteristics of an exemplary balloon according to the invention.

Figure 7 is a cross-sectional view showing a dilator balloon element according to the present invention.

Figure 8 is a side elevation view of a modified form of a balloon element according to the invention.

Detailed description

Referring in detail to the drawings, in the which equal reference numbers designate equal elements, Figure 1 shows a part of a balloon catheter, designated generically by reference number 10. It should be understood that balloon catheters can be used in angioplasty or in procedures that affect other vascular systems or cavities of the body, and can be applied with a guide wire to use other techniques familiar to art experts.

The balloon catheter 10 comprises a tubular body elongate 12, whose distant end is represented in Figure 1. Inside the tubular body 12 there is a cavity 14, which is extends along the tubular body 12.

Attached to the distant end of the tubular body 12 there is a ball element 16. As seen in Figure 1, the inside of the ball element 16 is communicated with the cavity 14, so that cavity 14 can serve as a source of Inflator fluid for the balloon element 16.

It also passes through cavity 14, and so concentric with elongated tubular body 12, a tubular body inner 18. The inner tubular body 18 in turn provides a cavity 20.

A distant end 22 of the balloon element 16 is attached, by adhesive or other suitable fastener, to the outer surface of the inner tubular body 18.

The tubular body 12 and the inner tubular body 18 are typically made of flexible structural materials and relatively strong, such as high density polyethylene, although other suitable materials may be used.

As seen in Figure 1, the element of balloon 16 is generically cylindrical, with neck portions 24 and 26 conical trunks whose respective ends have a diameter corresponding to the outer diameter of the tubular body 14 and the inner tubular body 18, respectively.

As described below, the element of Balloon 16 is molded with a desired wall shape and thickness. Those skilled in the art will appreciate that the characteristic of balloon dilation is a function, among other factors, of thickness of wall and of the material with which the element of ball.

The deflated diameter of a balloon element 16 typical is substantially larger than the diameter of the tubular body 12 and of the inner tubular body 18 with which it is associated. Therefore, it is a conventional practice to fold the balloon element forming a series of lobes (typically between two and five) and wrap the balloon element 16 folded over the bodies tubular (as seen in Figure 7) so that the profile Deflated stay low. A low profile is a feature desirable for balloon elements.

The walls of the balloon element 16 are constituted at least by an inner layer 28 and a layer exterior 30, which will be described in detail below. This provided within the present invention the possible use of additional layers in the wall.

Referring to Figure 5, it is shown graphically an idealized representation of the characteristic of dilation of a balloon element 16 according to the present invention. Thus, during the initial part of the balloon element dilation (16) (designated in Figure 5 as pressure range A), the ball It expands indeformably according to the pressure / diameter curve designated as "Diam. A". As can be seen, the element of ball adopts a dilated diameter that varies relatively little in function of increasing inflation pressure. Within the range of pressure "A", the ball element 16 provides some adequate expansion pressures and predictable diameters over a relatively large pressure margin, and with this margin of pressure is with which the stent is applied. If he surgeon wants to continue dilating the stent, the surgeon applies on the balloon element 16 a pressure greater than the pressure range "A" and higher than a transition pressure "T", entering in a pressure range (identified in Figure 5 as a margin of pressure "B") in which the balloon element 16 has a deformable characteristic.

Within the pressure range B, it can be done that the balloon is dilated substantially above diameter A with in order to adjust the diameter of the balloon and the stent. In others words, in the pressure range B, the balloon element 16 according to the present invention provides deformable dilation within an interval The surgeon can select the diameter Optimal end of ball adjustment by proper selection of the pressure. After this adjustment, and with respect to subsequent inflated, where appropriate, at pressures below the set pressure, the balloon element 16 adopts the adjustment diameter (Diam. "B") or stays close to it following the curve of pressure / diameter identified as Diam. "B" in the Figure 5.

According to the present invention, the inner layer 28, to which the outer layer 30 is attached, is manufactured with a polymeric plastic material that has a resistance to high traction and low initial compliance. It has been discovered that that inner layer 28 can determine the expansion characteristic of the balloon element 16. The layer exterior 30 is manufactured with a plastic material that has a abrasion and puncture resistance and smoothness desirable, and a distensibility superior to that of the inner layer 28. For reasons explained below, related to the manufacturing process of the balloon element 16, is also it is desirable that the material of the outer layer 30 has a point of melting substantially lower than the melting point of the material of the inner layer 28.

Those skilled in the art, familiar with materials that are conventionally used in manufacturing of balloon elements for balloon catheters, they will appreciate that the "high" term referring to the tensile strength of the materials used for balloon elements such as balloon elements 16 generically means a resistance to blowout greater than 275,7904-448,1594 MPa (40,000-65,000 pounds per square inch (psi)).

In the invention, the inner layer 28 is made of polyether ether ketone (PEEK). It has been discovered that this material, which presents a low initial distensibility and resistance to blowout of the order of 206,8428 to 689,476 MPa (30,000 to 100,000 psi), and preferably from 379.2118 to 689.476 MPa (55,000 to 100,000 psi), It is unexpectedly adaptable to its use in ball elements of the desired characteristics for the present invention. Specifically, when constructed according to the present invention, ball elements made of PEEK provide a dilatation characteristic that approximates the characteristic ideal represented in Figure 5. It has been discovered that balloon elements 16 manufactured based on an inner layer 28 of PEEK provide a selective variation of the diameter in small increments between 0.05 and 05 millimeters within the margin of indeformability, and large increments of 0.5 millimeters at 5 millimeters within the deformability range. Further, by judicious design of the ball element 16, it can position the transition pressure "P" within the range of 0.20265 to 2.0265 MPa (2 to 20 atmospheres), although more preferably from 0.8106 to 1.2159 (8 to 12 atmospheres), a transition pressure which provides a great final ball element versatility.

As will be clearly seen by the example described below, the inner layer 28 provides the element of ball 16 the desired tensile strength and determines essentially the expansion characteristic of the balloon element.  On the other hand, the outer layer 30 provides the balloon element 16 a very desirable resistance to abrasion and perforation. It also provides the ball element 16 with a soft "touch", and provides the balloon element 16 with a desirable memory of shape.

The outer layer 30, according to the shape of the presently preferred invention, is made of a copolymer in polyether block (PEBAX), but may consist of a material selected from the following: ABS (acrylonitrile butadiene styrene); ANS (acrylonitrile styrene); Delrin acetal; PVC (chloride polyvinyl); PEN (polyethylene naphthalate); PBT (Terephthalate polybutylene); polycarbonate; PEI (polyetherimide); PES (sulfide polyether); PET (polyethylene terephthalate); PETG (Terephthalate polyethylene glycol), with high and medium melting temperature: polyamides, aromatic polyamides, polyethers, polyesters, Hytrell, polymethylmethacrylate, polyurethanes: copolymers, EVA (vinyl ethylene acetate) or vinyl ethylene alcohol; polyethylenes of Low density, linear low, medium and high, latex rubber, FEP, TFE, PFA, polypropylenes, polyolefins; polysiloxanes, polymers of Liquid Crystal, Inomers, Surlins, Silicone Rubber, SAN (styrene acrylonitrile), nylons: 6, 6/6, 6/66, 6/9, 6/10, 6/12, 11, all PEBAX 12; polyether block amides; and elastomers thermoplastics

The walls of the balloon element 16 have preferably a joint thickness comprised approximately between 5.08 and 25.4 micrometers (0.0002 and 0.001 inches), being the preferred thickness of about 10.16 microns (0.0004 inches).

Various prior art have been described. techniques for manufacturing catheter balloon elements. For example, U.S. Patent No. 5,264,260, issued on 23 from November 1993 to SAAB, describes a process to manufacture a PET balloon element by axially stretching steps and radially expand a parison or piece of tube to form a single wall element. In U.S. Patent No. 5,348,538, issued on September 20, 1994 to Wang et al., Is describes a process for manufacturing a balloon element that consists to extrude a hollow tube, blow a ball from the tube, and anneal the ball, each of whose stages includes apparently several sub-stages. In U.S. Patent No. 5,270,086, granted on December 14, 1993 to Hamlin, it is suggested the manufacture of a multi-layered balloon element by the coextrusion of multiple polymers through a matrix.

The process by which they are manufactured preferably the balloon elements according to the present invention, and which constitutes an aspect of the present invention, will be described then referring to a preferred embodiment of the balloon element 16 in which the inner layer 28 is PEEK and the outer layer 30 is PEBAX.

In this regard, the PEEK tube can be extruded using conventional equipment and techniques, and can be provided with a surface coating with the desired material for the outer layer 30. The material that will constitute the layer outer 30 can be applied on PEEK tube of various ways, but the currently preferred technique is to apply through a secondary extrusion process a coating of the material for the outer layer 30 on the layer material interior, not very differently from the way in which the electrical cable insulation.

Below is an example of manufacture of a balloon element using the process previously described:

Example

Extrusion

First, a polyether ether ketone (PEEK) tube was extruded in a Killian extruder using conventional techniques and collected in coils about 1,524 m (about 5,000 feet) in length suitable to form numerous balloons. The PEEK tube was inserted into the extruder head, into the mandrel, and joined with the casting pipe. An outer lining of a polyether block copolymer (PEBAX) was concentrically extruded with the tube, the thickness of which was determined and adjusted by the speed of the extruder screw and the speed of traction, as well as the geometry of the equipment. The PEEK tube, already with the outer lining, was collected in a coil located at the end of the extrusion line. The final dimensions of the resulting bilayer tube were 0.635 x 1.016 mm
(0.025 in x 0.040 in).

Balloon treatment

Balls were formed from the bilayer tube using conventional ball blowing equipment that included hot molding dies with a 3.5 mm x 20 mm mold in A single forming operation. To form the balls you they used pressures between 413 and 1,723 KPa (60 and 250 psi) and heated for approximately 45 seconds. TO then the balls were cooled (5 seconds) by convection cooling The mold temperature was maintained at 132 ° C ± 10 ° C (270 ° F ± 50 ° F). The tube was axially oriented on the machine in its cold state before molding it by blown during the secondary extrusion process; during the secondary process it took little or no axial orientation additional.

Characteristics of the ball

The 3.5 mm balloon thus formed, with some dimensions of 0.8382 x 1.0414 mm (0.033 in x 0.041 in) had a double wall with a thickness between 0.0254 and 0.0889 mm (0.0010 in and 0.0035 in). The inner layer of PEEK constituted approximately 25% of the thickness of the double wall, while PEBAX constituted approximately the remaining 75% of the thickness of The double wall The touch and clarity of the ball were excellent and no delamination was observed between one layer or another.

Puncture resistance

The average drilling forces with sharp point was 453,592 g (1.0 lbs), while those of a ball element made solely of polyethylene were of 362.8736 to 408.2328 g (0.8 to 0.9 lbs) with a thickness slightly greater than 0.1016 mm (0.004``). In the blunt tip drilling test or rounded, the PEEK / PEBAX ball element above described was able to withstand 1,13398 kg (2.5 lbs), and 1.04326 kg (2.3 lbs) uncoated. The polyurethane coated PET gave a value of 1.02 Kg (2.25 lbs). The uncoated PET gave a value 544.31 g (11.2 lbs), with total wall thicknesses identical

Figure 6 represents the characteristics of dilation of the exemplary balloon element described previously.

In an alternative process to manufacture a balloon element 16, the balloon element can be manufactured extruding separately the materials of the inner layer 28 and of the outer layer 30 and joining them later. For example, you can first create a ball by extruding PEEK, and then make a second independent tubular extrusion with a material of polyethylene. The polyethylene material can be degraded from a manner known in the art, for example by radiation, and dilated in an independent operation to create a "retractable" tube It shrinks by heat. The placement of the retractable tube on the PEEK ball previously formed, followed by heating of the Retractable tube to make it retract to the diameter of the extruded PEEK piece, produces an outer layer of polyethylene on the PEEK ball. It will be understood, of course, that one could apply the described shrink tube technique to include layers additional on part or all of the ball to modify selectively the behavior of the ball.

Referring to Figure 8, if for example you want to avoid rapid dilation of the central part of the element of ball 16 during operation thereof, a additional layer 32, for example of polyethylene, only in the part center 38 of the ball. With this arrangement, the presence of the layer additional 32 of polyethylene serves so that parts 24 and 26 of the balloon element 16, located on both sides of the central part 38, they expand more quickly than the central part 38. Naturally, no it is necessary that the additional layer 32 cover the entire surface of the inner layer 28, although in some cases, and perhaps in most them, this may be desirable. Either way, it will be understood that the construction with a single multilayer wall described previously it greatly increases versatility and, in Ultimately, the usefulness of the ball element 16.

Figure 7 illustrates a balloon catheter 10 with a 16-layer balloon element 16 in the folded form that it would have during application at the site of an injury or during stent placement It has been discovered that the use of a layer outer 30, such as a PEBAX layer, improves behavior of the balloon element 16 in two ways: first, as illustrated in the previous example, through a reasonable choice of outer layer material 30 an element of 16 ball more resistant to perforations by external elements such as surgical instruments, calcified lesions or even, in some rare cases, the stent. Second, the layer exterior 30 tends to improve the "shape memory" that has the balloon element 16, so that when deflated, the balloon element 16 tends to return to its original folded form in instead of forming a simple flat "wing". The ball elements high pressure known so far do not usually have a enough memory in the way that makes them return to their form Original folded after use.

It should be understood that the present invention can be implemented in other specific ways within reach of the appended claims.

Claims (10)

1. A multi-layered balloon (16) to attach it to a medical catheter (10), comprising: an inner layer (28); an outer layer (30) adhered to said layer inside the ball, whereby said inner layer and said layer exterior provide a laminated balloon wall; said inner layer being made with a material plastic that has high tensile strength and low initial distensibility and said outer layer being manufactured with a plastic material that has an abrasion resistance and a distensibility greater than those of said inner layer; said balloon being characterized by a deformability characteristic described by a continuous and nonlinear deformability curve, said deformability curve having an initial indeformable inflation margin, a transition point and a second deformable inflation margin, whereby during a phase Initial inflation said ball behaves according to said initial inflation margin, and during a second inflation phase of said balloon, the mentioned ball behaves according to said second inflation margin; Y said balloon being further characterized in that said inner layer consists essentially of polyether ether ketone. 2. A dilator balloon according to claim 1, in which said outer layer is coextensive with the surface of said inner layer. 3. A dilator balloon according to the claims 1 or 2, in which said outer layer is essentially constituted for a material selected within the group consisting of: ABS (Acrylonitrile Butadiene Stirene); ANS (acrylonitrile styrene); Delrin acetal; PVC (polyvinyl chloride); PEN (naphthalate polyethylene); PBT (polybutylene terephthalate); polycarbonate; PEI (polyetherimide); PES (polyethersulfone); PET (Terephthalate polyethylene); PETG (polyethylene glycol terephthalate), with temperature High and medium melting: polyamides, aromatic polyamides, polyethers, polyesters, Hytrell, polymethylmethacrylate, polyurethanes: copolymers, EVA (vinyl ethylene acetate) or alcohol of vinyl ethylene; low density, linear, medium and low density polyethylenes high, latex rubber, FEP, TFE, PFA, polypropylenes, polyolefins; polysiloxanes, liquid crystal polymers, inomers, Surlins, silicone gums, SAN (acrylonitrile styrene), nylons: 6, 6/6, 6/66, 6/9, 6/10, 6/12, 11, all PEBAX 12; polyether amides in block; and thermoplastic elastomers. 4. A dilator balloon according to claim 1, wherein said outer layer is essentially composed of PEBAX 5. A dilator balloon according to claim 1, at which said transition point of the deformability curve, located between said initial indeformable inflation margin and said second deformable inflation margin, is between 0.20265 and 2,0265 MPa (2 and 20 atmospheres). 6. A dilator balloon according to claim 5, at which said transition point is between 0.8106 and 1.2159 MPa (2 and 20 atmospheres). 7. A dilator balloon according to claim 5, in which said outer layer of the ball is composed essentially by a plastic polymeric material that has a point melting lower than polyether ketone. 8. A dilator balloon according to claim 1, in which said inner layer is essentially constituted by an extruded tubular sheet that, in a deflated state, has a cross section comprising a plurality of lobes circumferentially separated; said outer layer consisting of an extrusion secondary that is superimposed on said inner layer and that retains the cross section of said outer layer when the ball is in deflated state, which facilitates the folding the ball. 9. A procedure to make a ball (16) multilayer to attach it to a medical catheter (10), useful for make dilations and place stents, which includes the stages from: in a first stage of extension, extrude a plastic tubular sheet for the inner layer (28) of the ball, said sheet being manufactured with a material that has a high tensile strength and low compliance initial; at an additional extension stage, extrude and adhere to the outer surface of said inner layer already removed, at least one additional layer (30) consisting of a plastic material that has an abrasion resistance and a distensibility greater than those of said inner layer, and which has a melting temperature lower than the melting temperature of inner layer material; Y mold the bonded layers to form a ball; in which said first extrusion stage is effect by extruding a plastic tubular sheet of polyether ether ketone 10. A method according to claim 9, in which said second extrusion stage is performed by extruding an essentially PEBAX layer on said tubular sheet of plastic.