EP0334567A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Improvements in synthetic vascular grafts
Assignee: University of Liverpool
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Filing: 1989-03-17
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Granted: —
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Expires: 2009-03-17
Abstract
Abstract A synthetic vascular graft (10) has a fibrous structure (11) and mechanical properties matching substantially mechanical properties of its natural counterpart, the fibrous structure including coating means of non-biodegradable elastomeric material for protecting fibres of the structure from tissue and capillary ingrowth into the wall of the graft, the coating (12) being of a material and thickness not to alter adversely the mechanical properties of the graft before the coating (12) is present. Alternatively or additionally, individual fibres within the structure are coated.
Inventors
- 👤 David Annis
- 👤 John Phillip Berry
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 14:09
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/28; A61L27/34; A61F; A61F2/00; A61F2/02; A61F2/04; A61F2/06; A61L27/50; A61L27/507
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
71 words
A synthetic vascular graft having a fibrous structure and mechanical properties matching substantially mechanical properties of its natural counterpart, the fibrous structure including coating means of non-biodegradable elastomeric material for protecting fibres of the structure from tissue and capillary ingrowth into the wall of the graft, the coating means being of a material and thickness not to alter adversely the mechanical properties of the graft before the coating means is present.
Claim 2
Dependent Claim
71 words
A synthetic vascular graft having a fibrous structure and mechanical properties matching substantially mechanical properties of its natural counterpart, the fibrous structure including coating means of non-biodegradable elastomeric material for protecting fibres of the structure from tissue and capillary ingrowth into the wall of the graft, the coating means being of a material and thickness not to alter adversely the mechanical properties of the graft before the coating means is present.
Claim 3
Dependent Claim
24 words
A synthetic vascular graft as claimed in Claim 1 wherein the graft before application of the coating means is an electrostatically spun polymeric graft.
Claim 4
Dependent Claim
33 words
A synthetic vascular graft as claimed in Claim 1 or Claim 2 wherein the coating means includes an external coating of the graft to present an impervious covering against tissue and capillary ingrowth.
Claim 5
Dependent Claim
22 words
A synthetic vascular graft as claimed in Claim 3 wherein the external impervious coating is of a thickness between 40µm and 100µm.
Claim 6
Dependent Claim
33 words
A synthetic vascular graft as claimed in Claim 3 or Claim 4 wherein the external impervious coating is applied from a solution of 40% SILASTIC (Trade Mark) weight for weight in 60% hexane.
Claim 7
Dependent Claim
33 words
A synthetic vascular graft as claimed in any one of Claims 3 to 5 wherein the external impervious coating is applied by dipping the uncoated graft in a solution of the elastomeric material.
Claim 8
Dependent Claim
30 words
A synthetic vascular graft as claimed in any one of Claims 3 to 5 wherein the external impervious coating is applied by painting the elastomeric material on the uncoated graft.
Claim 9
Dependent Claim
26 words
A synthetic vascular graft as claimed in any one Claims 3 to 5 wherein the external impervious coating is applied by spraying to the uncoated graft.
Claim 10
Dependent Claim
33 words
A synthetic vascular graft as claimed in any one of Claims 3 to 5 wherein the external impervious coating is applied by electrostatically spinning the elastomeric material to the graft without the coating.
Claim 11
Dependent Claim
30 words
A synthetic vascular graft as claimed in any one Claims 1 to 9 wherein the coating means comprise a coating of individual fibres of the fibrous structure throughout the structure.
Claim 12
Dependent Claim
32 words
A synthetic vascular graft as claimed in Claim 10 wherein the individual fibre coatings are achieved by application of a solution of 2.5% SILASTIC (Trade Mark) weight for weight in 97.5% hexane.
Claim 13
Dependent Claim
31 words
A synthetic vascular graft as claimed in Claim 10 or Claim 11 wherein the individual fibre coatings are applied by dipping the uncoated graft in a solution of the elastomeric material.
Claim 14
Independent Claim
45 words
A method of providing an impervious outer layer of non-biodegradable elastomeric material on an electrostatically spun structure comprising the steps of forming a solution of said non-biodegradable material, dipping said electrostatically spun structure mounted on a former into said solution, and drying the coated structure.
Claim 15
Independent Claim
45 words
A method of providing an impervious outer layer of non-biodegradable elastomeric material on an electrostatically spun structure comprising the steps of forming a solution of said non-biodegradable material, dipping said electrostatically spun structure mounted on a former into said solution, and drying the coated structure.
Claim 16
Dependent Claim
19 words
A method as claimed in Claim 13 including a curing step after drying where the material is silicone rubber.
Claim 17
Dependent Claim
16 words
A method as claimed in Claim 14 wherein curing takes place at 75°C for ½ hour.
Claim 18
Independent Claim
29 words
A method as claimed in any one of Claims 13 to 15 wherein the structure is rotated slowly during the drying step to provide evenness of the outer layer.
Claim 19
Independent Claim
27 words
A method as claimed in any one of Claims 13 to 16 wherein the solution is of 40% SILASTIC (Trade Mark) weight for weight in 60% hexane.
Claim 20
Independent Claim
66 words
A method of coating individual fibres throughout the structure of a synthetic vascular graft having a fibrous structure, which method comprises the steps of submerging the graft in a solution containing elastomeric material at a strength to enable full passage of the solution through the structure, applying a vacuum to a vessel containing the submerged structure, releasing the vacuum, removing the graft and drying the graft.
Claim 21
Independent Claim
66 words
A method of coating individual fibres throughout the structure of a synthetic vascular graft having a fibrous structure, which method comprises the steps of submerging the graft in a solution containing elastomeric material at a strength to enable full passage of the solution through the structure, applying a vacuum to a vessel containing the submerged structure, releasing the vacuum, removing the graft and drying the graft.
Claim 22
Dependent Claim
21 words
A method as claimed in Claim 18 wherein the solution is 2.5% SILASTIC (Trade Mark) weight for weight in 97.5% hexane.
Claim 23
Dependent Claim
31 words
A method as claimed in Claim 18 or Claim 19 wherein the drying step involves placing the graft in a chamber at 40°C and 40% relative humidity for approximately one hour.
Claim 24
Independent Claim
23 words
A method as claimed in any one of Claims 18 to 20 wherein the method steps are repeated to produce the final graft.
Claim 25
Independent Claim
56 words
A method of coating a synthetic vascular graft having a fibrous structure, the coating being both of individual fibres and an external impervious coating, which method comprises the combination of a method as claimed in any one of Claims 18 to 21 followed by a method as claimed in any one of Claims 13 to 17.
References Cited (Backward Citations)
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