DE102017010422A1 - Balloon with multilayer wall construction for the dynamic sealing of organs and cavities in the body - Google Patents

Abstract

The invention describes a multilayer extruded balloon sheeting, which preferably has an outer PUR layer and integrated in the interior of the balloon a PVC layer, wherein the PVC layer by its plastic, non-elastic type of deformation a damping effect on the opening kinetics of ösen- or channel-like formations of residual shaped, convoluted invaginated, placed in situ balloon bodies on the elastic, under tension deforming PU layer developed, and so reduces the opening of the eyelets or channels at passing pressure drop in the balloon.

Description

In many catheter applications, it is necessary to position a balloon-like body in such a way that it occludes or fills a lumen or inner space in such a way that the respective space that is physiologically adjusting within the framework of the respective body function is filled as completely as possible, ie without remaining residual space will be preserved, but in its form as far as possible.

Thus, with the smallest possible transmural pressure exerted by the balloon, the balloon body should produce an efficient seal, occlusion or space filling tamponade, especially if the cross section of the organ or cavity is continuous, for example cyclical, following the motility of the organ or body cavity changed its shape.

Basic solutions to the problem of dynamic sealing have already been found in EP 1061984 B1 Tracheostomy device made. Here, the seal of a trachea is described, which is based essentially on the use of very thin-walled balloon foils made of polyurethane. The shaped diameter of the balloon body thereby exceeds the diameter of the trachea, which causes the formation of a typical folding pattern of the balloon envelope in the tracheal placed balloon when filling the oversized balloon in the trachea. The excess balloon material thereby inverts into radially arranged invaginations, which form a channel-like formation at the blind inner end of the fold. The self-adjusting size or the diameter of these tubules is in addition to the structural-technical design of the balloon envelope itself, essentially dependent on the pressure prevailing in the balloon filling pressure acting on the eyelets. As the inflation pressure decreases, the eyelets begin to open drop-shaped towards the base of the invagination. As the pressure drops further, the eyelet fully opens towards the base, and transitions into a U-shaped configuration. Depending on the degree of balloon invagination opening, the sealability of the cuff results.

In the EP 1061984 B1 described balloon technology solves the problem of diameter of the folding eyelet on the basis of particularly thin-walled balloon films, which usually form even at low pressures tight Ösendurchmesser and ensure a correspondingly good sealing performance, even if the inflation pressure in the balloon due to the balloon organtus, organzyklisch fluctuates.

A particular challenge is the sealing of organs that lie in the thorax of a patient, such as the trachea (trachea) or the esophagus (esophagus). Both are hollow organs that are placed in the thoracic cavity or pass through the thoracic cavity. In the thorax, they are exposed to cyclical pressure fluctuations that occur as part of the thoracic respiratory work performed by the patient or during normal spontaneous respiration or even during mechanically assisted breathing.

If, due to respiratory mechanics, the patient experiences a decrease in intra-thoracic pressure in the thorax, this temporary pressure loss is transmitted to the tracheal and oesophageal walls. As a result of the pressure loss, there is a temporary dilation of the trachea and the esophagus, which in turn leads to a pressure loss of tracheal and oesophageal sealing balloon cuffs. At the moment of widening of the organ lumen or the release of the organtoon, the diameter of the terminal loop formations widens, which is passing, ie for the moment of widening associated with an increased permeability of the eyelets or a temporary loss of seal.

In the current literature on the sealing behavior residual, ie on an excessively shaped balloon body, the ability to produce an organ-compatible or functionally organ-compatible seal is tested predominantly on static viewing models. For example, in a study carried out by Bassi and colleagues [ An in vitro study to assess determinant features associated with fluid sealing in the design of endotracheal tube cuffs and excerted tracheal pressures; Bassi et al .; Critical Care Medicine, 2013; 41: 518-526 ] intubates a rigid tube with a tracheal tube and then places a column of water over the filled balloon seal. The permeabilities found in the static model are already in the range of milliliters per minute for PVC-based balloons. Only PUR-based, very thin-walled balloons allow a good or sufficient seal even with filling pressure drops to 15 mbar. At filling pressures below 15 mbar, however, PUR balloons with walls below 20 μm also show an incipient widening of the oeseal diameter. As in the case of PVC balloons, the eye opens from the blind end to the base of the invagination and allows more fluid to pass through. The elastic erection properties of PUR are decisive here. While eyelet-like envelopes of a folding of a film in PVC-based films develop a comparatively small righting force opening the loop, the elasticity of PUR films creates a permanently elastic opening force, the more the more the more Inflation pressure of the balloon is reduced as an effective counterforce.

However, static models are incapable of reflecting the breath synchronously varying changes in the tracheal diameter or organ tone and / or in the evaluation of the sealing behavior. The special dependence of the seal of tracheal tube balloons (cuffs) on the thoracic respiratory work of a patient is described for example by Badenhorst and colleagues [ Changes in cuff pressure during respiratory support, CH Badenhorst, Critical Care Medicine 1987, 15, 4, 300-302 ]. In spontaneous breathing patients, the cuff pressure measured outside the body, in some cases, is well below the 15 mbar range and may even, following thoracic pressure, assume sub-atmospheric levels. As a rule, this results in a nearly complete or complete loss of seal.

The present invention describes a solution to improve the dynamic sealing behavior of cyclically loaded balloon bodies, wherein the wall of the balloons have a multilayer construction of PVC and PUR layers.

The invention combines material properties such that a thin-walled, particularly small eyelets forming balloon results, on the one hand has the required mechanical stability, and on the other hand minimizes the elastic re-establishment of the eyelet with pressure drop in the balloon.

Combinations of PUR outer layers, which are combined with PVC inner layers, are particularly advantageous here, wherein the wall thickness of the PUR layer is reduced to a maximum size, in order to ensure dimensional stability and load stability of the balloon, but the elastically opening effect on the To reduce eyelets as much as possible. In order to further restrict the dynamics of the opening of the loop-like formations or to make them sluggish, the PURelastic PUR layer is combined with a non-elastic, plastically sluggish PVC layer.

If, for example, a PUR film layer of Shore hardness 80A to 95A and a ply thickness of 5 to 10 microns with a PVC film layer of Shore hardness 50A to 70A and a layer thickness of 20 to 30 .mu.m combined, a sufficiently slowed, sluggishly damped opening effect sets in passageren or pressure changes, which advantageously reduces the passage of a medium of a substance through eye-like or out of the eyelets channel-like formations. The effect is all the more pronounced, the thicker the PVC wall or thin-walled the PUR layer.

Furthermore, the described multi-layeredness of the balloon envelope makes it possible to produce PVC in wall thicknesses of less than or equal to 30 .mu.m in such a way that uniform wall thicknesses can be produced during the blowing process. The PUR content in the co-extruded raw tube formed by blow molding into a balloon serves as a stabilizing, elastically expanding, uniform shaping enabling carrier, which, so to speak, entrains the plastically behaving PVC portion in the mold cavity during the molding and uniformly in the mold distributed balloon envelope distributed.

In a corresponding manner, the PUR layer also stabilizes the balloon according to the invention within the body in the case of load-bearing organ mechanics. Herniated, no longer reversible, plastic bulges of the thin-walled balloon envelope are avoided by the PU content even when it comes to passageren higher pressure increases in the balloon. Without stabilizing co-layer, PVC-based balloons in the range of or below 30 μm are structurally too unstable or not sufficiently dimensionally stable in order to be used safely in the patient.

The multilayered nature of a balloon envelope stabilized by a PUR content is also advantageous for the reduction of migration or permeabilities of water or gases. Thus, in combination with PVC, because of the better barrier properties against polar media, in particular the passage of water into the balloon can be reduced or the condensation of water in the balloon can advantageously be reduced.

• zeigt einen erfindungsgemäßen Aufbau einer Ballonhülle aus zwei Ko-Lagen.

The features of the invention are described in detail in the following figures:

• shows a construction according to the invention of a balloon envelope of two co-layers.

shows a convolution formation 1 at the blind, usually radially inward of the balloon end of the invagination residual balloon envelope 2 , The eyelet 3 forms channel-like structures 4 that absorb and transfer liquids or substances. The wall of the folding formation has an outer layer 5 made of PUR, which is a Durometer to Shore of 80A to 95A , especially advantageous from 85 to 90 Has. The inner situation 6 Made of PVC the preferred durometer 50A to 70A , especially preferred 55A to 65A , The two layers are preferably extruded without adhesion promoter as a tube blank. The balloon is formed by blow molding the raw tube by initial heating and subsequent cooling of the balloon formed in a mold cavity.

The wall of a balloon according to the invention should not exceed 30 to 35 μm in terms of a preferred membrane-like thinness. Preference is given to this total wall thickness the ratio of the wall thicknesses of the PUR layer to the PVC layer 1 to 2 to 3 ,

For example, in a specific arrangement of PUR, hardness occurs 85A and a thickness of 10 microns with a layer of PVC of hardness 60A and a thickness of 20 microns to a pressure drop of 30 to 5 mbar, there is an increase in the seal of the balloon-determining, the transmitting Ösenfläche of 10 to 25, but usually not more than 15%. The diameters of the eyelets of such balloons are at a filling pressure of 30 mbar at about 30 to 80 microns, predominantly at about 60 microns.

Particularly in the case of short-term, cyclical changes in the balloon filling pressure of, for example, 20 changes per minute and pressure changes from 30 mbar to 5 mbar, the sealing properties of the balloon remain largely intact. In secretions with saliva-like consistency, the free flow comes to a complete halt in the case of the in-situ-positioned balloon diameters, and pump-like, effervescent effects on the eye, or the forming channels, remain largely unaffected by cyclic pressure changes.

In the context of the invention, the PVC and PUR existing balloon layers can also be arranged vice versa, with it PVC layer is then on the outside of the balloon.

Furthermore, for example, 3-ply embodiments are possible, wherein the PUR layer is preferably sandwiched between two PVC layers. For example, with a total wall thickness of 30 to 35 μm, the distribution of the individual layers can be 13 μm PVC on the outside, 8 μm PUR on the outside with 13 μm PVC on the outside. This embodiment is particularly advantageous in limiting migration effects of polar substances, such as water, and their accumulation in the balloon interior.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1061984 B1 [0003, 0004]

Cited non-patent literature

• An in vitro study to assess determinant features associated with fluid sealing in the design of endotracheal tube cuffs and excerted tracheal pressures; Bassi et al .; Critical Care Medicine, 2013; 41: 518-526 [0007]
• Changes in cuff pressure during respiratory support, C.H. Badenhorst, Critical Care Medicine 1987, 15; 4, 300-302 [0008]

Claims (1)

Device consisting of a multi-layered extruded balloon foil material which preferably has an outer PUR layer and integrated in the interior of the balloon a PVC layer, wherein the PVC layer by their plastic, non-elastic type of deformation a damping effect on the opening kinetics the ösen- or channel-like formations of residual shaped, convoluted inverted, placed in situ balloon bodies on the elastic, under tension deforming PUR layer developed, and so reduces the opening of the eyelets or channels at passing pressure drop in the balloon.

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