摘要:
A radially expandable fluid delivery device for delivering a fluid to a treatment site within the body is disclosed. The fluid delivery device is constructed of a microporous, biocompatible fluoropolymer material having a microstructure that can provide a controlled, uniform, low-velocity fluid distribution through the walls of the fluid delivery device to effectively deliver fluid to the treatment site without damaging tissue proximate the walls of the device. The fluid delivery device includes a tubular member defined by a wall having a thickness transverse to the longitudinal axis of the tubular member and extending between an inner and an outer surface. The wall is characterized by a microstructure of nodes interconnected by fibrils. The tubular member is deployable from a first, reduced diameter configuration to a second, increased diameter configuration upon the introduction of a pressurized fluid to the lumen. The tubular member includes at least one microporous portion having a porosity sufficient for the pressurized fluid to permeate through the wall. Substantially all of the nodes within the microporous portion are oriented such that spaces between the nodes form micro-channels extending from the inner surface-to the outer surface of the wall.
摘要:
A vascular endoprosthesis is formed of a tubular liner preform with a continuous surface and having a diameter smaller than that of an intended vessel. The liner is inserted to a treatment site, and its sheet material undergoes a radially-directed expansion to a final size that fits the vessel. Insertion and in situ expansion are achieved using a catheter assembly in which either an internal stent, such as a stiff-filament helically woven tube, or an inflatable balloon urge the liner preform outwardly against the inner wall of the vessel. The stent, or one or more simple internal snap-rings anchor the expanded liner in place. The expanded liner is porous, or becomes more porous during expansion, and one or more aspects of its porosity are tailored to the intended treatment goal of immobilizing treatment material, isolating cells, or permitting controlled permeation of selected materials.
摘要:
A porous tube suitable for use as a vascular graft prosthesis and a method of making it is disclosed. It has a structure of porous polytetrafluoroethylene having a fibrous structure of nodes and fibers connecting the nodes together and an integrated intrawall circumferential support adjacent to areas of variable porosity. This invention provides a polytetrafluoroethylene polymer in a porous form useful as artificial internal organs for, for example vascular bypass, vascular access, and endovascular prosthesis. PTFE walls are found with radial zones of differing porosity are described.
摘要:
A process for producing a shaped porous article includes the steps of providing an extrudate of a fluoropolymer material which is capable of being stretched and bilaterally stretching the extrudate along a longitudinal axis. The stretching step is carried out under conditions sufficient to yield an article which is substantially uniformly stretched over a major portion of its length. After stretching, the material has a unique through-pore microstructure characterized by elongate nodes connected by fibrils. The stretched material is sintered while being maintained in its stretched state to produce the shaped porous article. A significant feature of the inventive process is that stretching is carried out by displacing both ends of the extruded material as opposed to known method wherein only one end of an extruded material is stretched, resulting in a microporous fluoropolymer article which are different than conventional fluoropolymer stretching/expansion processes.
摘要:
A barrier device is formed of a barrier component that can exhibit anti-inflammatory properties, non-inflammatory properties, and/or adhesion-limiting properties, as well as generate a modulated healing effect on injured tissue. The barrier component can be a non-polymeric cross-linked gel derived at least in part from a fatty acid compound, and may include a therapeutic agent. The barrier device can have anchoring locations to provide an area on the barrier device to interface with an anchoring mechanism. The anchoring locations can include openings and/or anchor elements. The barrier device can also include truss structures that provide additional strength to the barrier component. The barrier device is implantable in a patient for short term or long term applications, and can include controlled release of the therapeutic agent.
摘要:
A hernia patch supporting tissue in-growth conforms to a tissue wall upon surgical installation and fixation within a patient. The hernia patch can include a base and positioning straps. The base is formed of two layers that are affixed to each other around the perimeter of the patch, for example by stitching. A stabilizing washer is provided between the two layers, and the stitch is provided peripherally around the stabilizing washer, keeping the washer free-floating between the layers. The base, positioning straps, and stabilizing washer are formed of a structure that does not separate the layers of the implant or form a space in the form of a pocket, and promotes more uniform and confluent tissue incorporation or in-growth after implantation. The hernia patch may further include a hydrolysable bioabsorbable cross-linked coating of a fatty acid based material, such as an omega-3 fatty acid based material.
摘要:
Exemplary embodiments of the invention provide a dispersing liquid for coating internal body tissues with a bio-absorbable oil, a method of making the dispersing liquid, methods of using the dispersing liquid and a kit for coating internal body tissues using the dispersing liquid. The dispersing liquid includes a suspension of a bio-absorbable oil suspended in a liquid carrier. The invention results in a uniform thin coating of bio-absorbable oil on internal body tissues.
摘要:
The wall of a prosthesis has a region which modulates communication through the porosity of the wall. The prosthesis is unitary, but may be assembled in successive bodies which are coalesced, so that the porous microstructure changes distinctly at stages through the thickness dimension of the wall. One embodiment is formed entirely of fluoropolymer, and has at least one surface adapted to support tissue regeneration and ingrowth. The modulation region is a stratum of high water entry pressure that reduces pulsatile hydraulic pressure transmission, or locally alters fluid-born-distribution of biological material through the wall and allows more natural gradients for tissue regeneration and growth in the outer region of the wall.
摘要:
A radially expandable support body is enveloped within a cocoon. In a preferred construction, the support is a stent, and a tube of polymeric material, e.g. polytetrafluoroethylene (PTFE), passes through the interior of the stent body and is turned back upon itself over the stent to form a cuff. The assembly is then heated and the outer layer contacts and coalesces with the inner layer, closely surrounding the stent body within a folded envelope having a continuous and seamless end. In one embodiment, an end portion of the tube is expanded before folding back over the stent. The end portion, which becomes an exterior surface of the finished product, thus acquires a greater degree of porosity. Each end of the central tube may be so expanded, and folded back to seal all surfaces and both ends. The stent body itself may be a ring, or a short series of spaced-apart rings, or a wire or web, or a sheet possessing a number of apertures extending entirely through the sheet. The spaces or apertures are covered over or bridged by both the inner and outer polymer layers. The apertures, which may comprise under five to over eighty percent of the surface area of the stent, constitute regions or a grid of points through which the material is coalesced and continuously bonded, and around which strain is distributed by the support. These points or regions remain tacked together so expansion of the assembly does not delaminate the polymer or create flaps and pockets. In another embodiment, a two tube construction is cuffed and assembled into a similarly unitized and seamless stent. One tube is cuffed back, and the other tube covers the cuffed stent. In this embodiment both the tube thicknesses and porosities may differ substantially. For example the inner porosity may be selected to enhance blood flow or intimal regeneration, and the outer surface may have a porosity to encourage anchoring to external muscle tissue.