JP2004136120A - Graft with flanges for end side anastomosis - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new graft for access, i.e., a thigh tip end bypass graft, formed of extended micropore polytetrafluoroethylene. <P>SOLUTION: This is a blood vessel graft 10 with flanges, which is made of the extended micropore polytetrafluoroethylene suitable for end side anastomosis and has an integrated polytetrafluoroethylene skirt on the end part, i.e. a cuff part 12 for promoting direct end side anastomosis without requiring a collar or patch for a vein between an artery and the bypass graft 10 with flanges made of the extended micropore polytetrafluoroethylene. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates generally to vascular grafts, and more particularly to end-to-side anastomotic vascular grafts for the purpose of bypassing obstructed or diseased portions of blood vessels. As a further feature, the invention includes a blood vessel having a terminal polytetrafluoroethylene flanged cuff portion sutured to the blood vessel to exhibit a polytetrafluoroethylene tissue boundary between the graft and the blood vessel. A polytetrafluoroethylene having an integral terminal polytetrafluoroethylene flange cuff portion that allows for an end-to-side anastomosis. The present invention also provides a method and apparatus for forming a flanged polytetrafluoroethylene cuff portion from a tubular polytetrafluoroethylene implant.

(Relationship with related applications)
This application filed with the United States Patent and Trademark Office, which concurrently served as the International Receiving Office under the Patent Cooperation Treaty, entitled "Apparatus and Method for Manufacturing Flanged Implants for End-to-End Anastomosis""Impla International Application"). The concurrently filed PCT Impra International Application, both assigned to Impla, is an applicant for all designated States except the United States, and includes Scott Randall, Roy Tang, and Albert El Ramay. Is the United States only applicant. Applicants further show here PCT International Application filed concurrently and hereby incorporated by reference.

(Background of the Invention)
The use of cuff implants for occlusion of peripheral vessels in the occluded state, and in particular, patch prostheses, is well known in the art. However, to date, autografts or synthetic grafts with a tip cuff formed of venous tissue at the anastomosis have been used. Examples of suitable cuff implants are described in JH Miller, "Use of Intravenous Cuffs and PTFE," Mirror Collar, Double Sounders (1989), "Vascular Surgery Techniques," Second Edition. "Improved Techniques for Polytetrafluoroethylene Bypass Implants", patch, described by pages 276-286, and by R. S. Taylor et al. Long-term use results ", 79: 348-354 (1992). Both mirror and tailor grafts are cuff grafts, both using polytetrafluoroethylene grafts with autologous venous cuffs at the anastomosis. Each of the mirror collar and the tailor patch uses venous tissue at the anastomosis to avoid compliant misalignment at the polytetrafluoroethylene tissue interface.

The present invention provides a new type of anastomosis for femoral lower leg bypass that is incorporated into a fluttering double valve configuration. The implant shape of the present invention provides optimal geometry for anastomosis as a function of hemodialysis properties. By optimizing blood flow from the bypass prosthesis to the artery, intimal hyperplasia is reduced with a concomitant increase in graft patency and reduced morbidity.

The present invention provides a method and apparatus for forming an integral polytetrafluoroethylene tip flange or cuff into expanded polytetrafluoroethylene (ePTFE). The device of the present invention comprises a tubular mold having radially extending slots forming an extension.

フ ラ ン ジ The flange cuff implant of the present invention is made as follows. First, an unsintered tubular PTFE vascular graft is formed by projecting a lubricant mixture of PTFE into a billet to form a tubular protrusion, and the tubular cuff is expanded 1). Cuff by applying a negative pressure to the section or 2) applying a positive pressure such that a portion of the tubular projection is radially separated through a tubularly projecting lumen by a highly compliant angioplasty balloon. To form a graft.

Various different attempts have been made to assemble tributary grafts. As early as 1938, Brown's U.S. Pat. No. 2,127,930 describes a bioabsorbent made of animal tissue and a binder by wrapping and forming a strip of processed animal tissue around a structural shape. A possible and surgically implantable tissue implant is disclosed.

U.S. Patent No. 4,909,979, issued March 20, 1990 to Posis, discloses a method of shaping a human umbilical cord for use as a vascular graft. This method uses a mandrel to support and shape the umbilical cord while shaping and treating the cord. A PTFE coating has been applied to the mandrel to facilitate placement of the umbilical cord on the mandrel. The shaping section of the mandrel has a plurality of vacuum openings in the mandrel. The umbilical cord is treated with ethanol and treated in vacuo until the cord is dry. The cord is then inflated for a therapeutic fixation solution, the umbilical cord is treated substantially airtight, and a vacuum is applied until it is circumferentially compressed and compacted around the mandrel formation.

U.S. Pat. No. 4,354,495, issued to Bodsky on October 19, 1982, discloses a PTFE tubing made of a moldable plastic such as polyurethane, acrylic acid, polyethylene, polycarbonate, or the like. Discloses a method of connecting to. The method includes forming a bulge or protrusion, then inserting the bulge into the mold, and molding a portion of the PTFE tube to mold a moldable plastic hub around the bulge in the mold. Selectively heating.

U.S. Pat. No. 4,957,508, issued to Kaneda et al. On September 18, 1990, discloses an elastic medical tube having a proximal end and a distal end that flank outwardly. . The outward projections of these ends are provided by forming the inner and outer surfaces of the tube to exhibit the opposite elastic properties, the inner surface exhibiting an expanding force, while the outer surface contracts. Show the power to do. The tube is made of high molecular weight polymer, preferably polyvinyl halide, polystyrene, polymer series, polymer series condensate, cellulose series high polymer, polyurethane series high polymer, polysulfone series resin, polyamide, etc. Or made with a mixture.

U.S. Pat. No. 5,387,236, issued to Noshiki et al. On Feb. 7, 1995, provides a vascular prosthesis and a vascular prosthesis matrix made of PTFE or other microporous material and provides a biological tissue. A method for producing a vascular prosthesis by adhering and trapping within the walls of a prosthesis matrix fragment of the invention. Fragments of biological tissue are vascular, connective, and muscle tissue and / or vascular endothelial cells, smooth muscle cells, and fibroblasts. The implanting process attaches cellular material to the inner wall of the graft and creates a pressure differential between the luminal and anti-luminal wall surfaces to entrap the tissue matrix within the microporous matrix of the vascular prosthesis Guided by

U.S. Pat. No. 4,883,453, issued Nov. 28, 1989 to Berry et al., Discloses a coronary aortic bypass graft and a method of making the graft. The implant and the plate are made of an electrostatically spun fibrous structure. The implant is adhered to the plate by placing the implant on the mandrel, applying adhesive to the surface of the plate surrounding the plate opening, and passing the mandrel through the plate opening until the implant contacts the adhesive. . The adhesive may be any suitable adhesive for the material forming the plate and the implant. According to the preferred embodiment referred to herein, the implant preferably has a tapered wall thickness where the wall thickness of the implant adjacent to the plate is greater than the distance to the plate. .

No. 5,110,526, issued to Hayashi et al. On May 5, 1992, discloses a process for producing a molded PTFE article. According to this step, the protrusion of the non-sintered PTFE is inserted into the sintered mold. The sintered mold has a diameter slightly larger than the outer diameter of the unsintered PTFE protrusion. The gap between the outer diameter of the unsintered PTFE protrusion and the inner surface of the sintered mold is on the order of 2% of the outer diameter of the sintered mold. The protrusion is drawn into the sintering mold via a plug inserted into the terminal lumen of the protrusion, a wire and a take-out reel. The protrusion of the PTFE is cut to match the length of the sintered mold, and the sintered mold is sealed to the end of the cut protrusion. The assembly is transferred to a sintering furnace and sintered. During sintering, the protrusions expand until they come into contact with the sintering mold and conform to the shape of the sintering mold. After cooling, the sinter protrusion shrinks away from the sinter mold and assumes the same shape corresponding to the sinter mold.

No. 3,196,194, issued Jul. 20, 1965 to Erie Jr. et al., Discloses a projection process for FEP-fluorocarbon tubing. The projecting step includes projecting a fluid FEP copolymer forming a tubular projection through a barrel projection device, placing the tubular projection in a heater, and compressing the tubular projection radially expanding the FEP projection. And heat-shrinkable tubing with memory function comprising a screw that cools the expanded protrusion to make the reduced diameter protrusion.

U.S. Pat. No. 4,503,568, issued to Madras on March 12, 1985, discloses an arterial bypass prosthesis for end-to-side anastomosis and reduction of anastomotic hyperplasia. Arterial bypass prostheses generally consist of a connecting element having a tubular inlet member, a tubular outlet member, and a heel member. The tubular inlet receives blood flow and provides an inlet passage therethrough. A tubular outlet member is coupled to the tubular inlet and is angularly displaced to provide a passage for blood flow from the inlet member. The heel member extends substantially coaxially from the outlet member. The distal end of the heel member is inserted through the open arteriotomy into the portion of the container upstream of the arteriotomy. The heel is rigid or has a continuous passage with the inlet and outlet members. The throat is provided between the tubular inlet and outlet members, and a circumferential skirt surrounds the throat. The skirt is adhered to the adventitia tissue of the blood vessel.

With particular reference to known methods for making PTFE materials, the following are cited as examples of state of the art and purposes. U.S. Pat. No. 4,482,516, issued Nov. 13, 1984, discloses a process for producing a high strength expanded PTFE product having a coarse microstructure. This patent is granted to Bauman et al. And shows up to 40% expansion. The resulting microstructure of the PTFE is then defined by the "roughness" guidelines, which means that the size of the nodes, ie height and width, and length of the fibrils are taken into account.

U.S. Pat. No. 5,376,110, issued on Dec. 27, 1994 to Zu et al., Discloses a blood vessel with collagen cross-linking performed under the influence of alternating pressure across the graft wall. A method of making an implant is disclosed. The alternating pressure is intended for cross-linking of the collagen fibers.

U.S. Pat. No. 4,743,480, issued to Campbell et al. On May 10, 1988, protrudes and expands a tubular PTFE product machined into a barrel and / or mandrel with a protruding spiral groove. A method is disclosed. The protrusion of the tubular PTFE product results in a protrusion having a node provided at an angle between 85 and 15 degrees from the longitudinal axis of the protrusion.

Finally, U.S. Pat. No. 4,234,535, issued to Okita on November 18, 1980, describes a relatively small diameter fiber on the inner surface of the tube and a fiber at least twice the outer diameter of the tube. And forming an expanded PTFE vascular graft having: The implant is manufactured by forming a tubular projection of PTFE and then driving and picking and placing it on a capstan. The drive system of the capstan conveys the protrusions through a heating set at a temperature of about 327 ° C., and then into a vacuum case causing a radial expansion of the protrusions at a temperature of about 327 ° C., and After radial expansion, the vacuum case is cooled to a temperature below the sintering temperature by the introduction of cooling air, whereby the tube is extended longitudinally to the expanded diameter by tension from the drive and pick-up capstan. Fix it. This patent also discloses and claims the use of cooling air conveyed through the tube lumen during the radial expansion process. By transporting the cooling air through the tube lumen, the temperature of the surface of the lumen is kept below the sintering temperature of PTFE. In this way, fibrils of different diameters are formed in the lumen and non-lumen.

In current clinical practice, a distal anastomosis between a bypass or access prosthesis and the distal artery is performed by inserting a venous element at the anastomosis site (Lynton) patch by anastomosing the prosthesis with a long venous patch to the artery. ), Not only direct anastomosis such as expansion of the prosthesis in the anastomotic region using a venous patch (Taylor patch), but also insertion of the venous cylinder between the prosthesis and the artery (Miller collar). Achieved. In femoral tip grafts, there is evidence that compliant inconsistency between the graft and susceptible arteries and blood circulation factors are the primary causes of thrombosis and the development of anastomotic intimal hyperplasia. Is being formed.
US Patent No. 2,127,930 U.S. Pat. No. 4,909,979 U.S. Pat. No. 4,354,495 U.S. Pat. No. 4,957,508 US Patent No. 5,387,236 U.S. Pat. No. 4,883,453 US Patent No. 5,110,526 U.S. Pat. No. 3,196,194 U.S. Pat. No. 4,503,568 U.S. Pat. No. 4,482,516 US Patent No. 5,376,110 U.S. Pat. No. 4,743,480 U.S. Pat. No. 4,234,535

The basic object of the present invention is to provide a new graft for access, a femoral tip bypass graft formed of expanded microporous polytetrafluoroethylene (ePTFE).

Another object of the present invention is to provide a femoral tip bypass graft made of ePTFE having a tip flange suitable for access, ie, the lower leg.

Another object of the present invention is to provide a femoral tip bypass graft formed of ePTFE having a tip flange suitable for access, i.e., an arterial-venous patch (AVP).

Another object of the present invention is to provide an apparatus and method for manufacturing a new graft for access, ie, a femoral tip bypass graft.

Still another object of the present invention is to provide a tubular polytetrafluoroethylene graft having a circumferential recess extending radially from the central axis of the tubular mold to form a distal flange. To provide a device and method for producing a new implant for an access, i.e., femoral tip bypass implant, utilizing the mold of the present invention.

A vascular graft suitable for the end-to-side anastomosis of the present invention includes:
An expanded tubular polytetrafluoroethylene implant having a proximal end and a distal end;
A flange portion made of polytetrafluoroethylene extended at the distal end of the tubular implant protruding outwardly from a central axis of the tubular implant;
The at least one flange portion is characterized by being an integral part that is continuous with the tubular implant.

According to one embodiment of the present invention, the expanded polytetrafluoroethylene tubular implant further comprises a reinforcing member provided circumferentially around a longitudinal direction of the tubular implant. .

According to one embodiment of the present invention, the at least one flange portion further comprises a collar extending around the entire outer circumference of the distal end of the tubular implant.

According to one embodiment of the present invention, the at least one flange portion further comprises two flange members projecting outwardly from a central axis of the tubular implant.

According to one embodiment of the present invention, the two flange members are substantially mirror symmetric to each other.

According to one embodiment of the present invention, the two flange members are substantially asymmetric with respect to each other.

According to one embodiment of the present invention, the tubular implant further comprises a first longitudinal region having a first lumen diameter, wherein the distal end of the tubular implant has a first lumen. Further comprising a second lumen diameter greater than the diameter.

According to one embodiment of the present invention, the first of the two flange members has a toe portion of the implant that is directed distally with respect to liquid flowing through the bypass implant, The second has a heel portion of the implant that is directed proximally with respect to liquid flowing through the implant.

According to one embodiment of the present invention, further comprising a crotch angle formed at a junction between the first and second flange members, wherein the crotch angle is between 45 ° and 180 °. .

According to one embodiment of the present invention, the first and second flange members each have a length of one to five times the lumen diameter of the expanded polytetrafluoroethylene implant. .

These and other objects, aspects, and advantages of the present invention will become more apparent to those skilled in the art from the following description of a preferred embodiment of the invention in more detail with reference to the accompanying drawings. There will be.

FIG. 1 shows an isolated crouching element with PTFE and a posterior thigh bypass to the tip implant. It is well known to use a PTFE graft to bypass the occlusion 3 of the femoral artery or the occlusion 4 of the crouching artery into the distal circulation. As described above, various cuff and patch technologies have been devised.

FIG. 2 shows that the venous element 8 of the saphenous vein, typically 3-4 cm, forms a cylindrical cuff extending outwardly from the artery 2 so that the arteriotomy opening of the crooked or tibial artery can be seen. And showing the mirror cuff 5 sewn to it. The venous element 8 is opened in the longitudinal direction and is formed in a collar shape by anastomosis to the arteriotomy using 6/0 or 7/0 prolene suture. The collar is then closed with a 6/0 prolane suture. The ePTFE implant 10 is cut to fit the circumference of the collar and then anastomosed to the collar using a continuous 5/0 prolane suture. The mirror cuff 5 is shown when the PTFE is anastomosed in a tibial artery, a crouching artery, or a continuous bypass procedure, for example, a femoral-clinch-shin.

FIG. 3 shows the tailor patch 7. In tailor patch procedures, veins 5-6 cm in length are typically taken from available components of the saphenous vein. The introduced vein is longitudinally open and shaped to form a diamond-shaped vein patch 8. The distal end of the ePTFE implant 10 is shaped into a U-shaped and V-shaped slot along the top surface of the ePTFE implant 10. The U-shaped open end of the ePTFE graft forms an ePTFE arterial suture line, while the V-shaped slot is sutured to the venous patch 8. The venous patch 8 is positioned along the V-shaped slot of the ePTFE graft 10 and in the correct orientation of the arteriotomy opening and is sutured to both the ePTFE graft 10 and the arteriotomy. I have. A suture line extends from the heel of the implant to the toe portion of the implant to complete the tailor patch bypass implant.

The patency of a standard end and side ePTFE graft / arterial anastomosis graft is between 21-60% patency in one year and between 14-38% patency in three years. Sex has been reported. One year patency using a mirror collar has been reported for ePTFE leg implants at 47%, and three year patency is 52%. One year patency using tailor patches is reported at 86% and three year patency is reported at 52%. According to the "Intravenous Vein Patch for Reconstruction of Blood Vessels" by Jay F. Chester and the latest information of hospital on February 3, 1993. Direct PTFE to arterial anastomosis has been criticized by mechanical strain of the arteries due to the relatively stiff PTFE and the formation of initial proliferation between the PTFE and sensitive arteries. These two factors are related to the high occlusion rate of direct PTFE to arterial anastomosis and the patency characteristics of low grafts. See CW Jamison et al., "Vascular Surgery," Fifth Edition, pages 330-340 (1994).

A preferred embodiment of a flanged implant is shown in FIGS. As shown in FIG. 4, a first embodiment of a flanged implant 10 is a dual valve in which a tubular ePTFE implant 11 is divided into two parts having flanges 12 and 14 with a bifurcated tip. Shape. In the end-side anastomosis where the end and the side contact each other, the distal end of the graft 11 is anastomosed with an artery incision formed in the artery 2 on the receiving side. To facilitate anastomosis, increase the conformability of the ePTFE between the graft 11 and the recipient artery 2, and optimize blood flow from the graft 11 to the recipient artery 2, The split flanges 12 and 14 project in opposite directions substantially perpendicular to the longitudinal axis of the implant 11.

If the graft 11 is placed in an end-to-end relationship with the receiving artery 2, the ends of the bifurcated flanges 12 and 14 are parallel to the longitudinal axis of the receiving artery 2 and The side artery 2 extends in the proximal and distal directions. The bifurcated flanges 12 and 14 preferably conform substantially to the curve of the receiving artery 2 and surround the bifurcated flanges 12 and 14 for an open arteriotomy. It has an elongated bulb-like shape located.

The bifurcated flanges 12 and 14 are preferably each formed to have a substantially oval shape with arcuate distal ends 18 and 20 terminating at toe portions 19 and 21. ing. The heel region 17 immediately contacts the tubular implant and the arcuate distal ends 18, 20 of the bifurcated flanges 12,14. The junction between the distal end 18 of the flange 12 and the distal end 20 of the flange 14 forms a crotch angle 16 in the heel region 17. Crotch angle 16 is preferably between 45 ° and 180 ° to maximize the strength of the implant in heel region 17.

The bifurcated flanges 12 and 14 may be symmetric or asymmetric with respect to each other. Choosing a bifurcated flange 12,14, either symmetric or asymmetric, preferably involves the specificity of the recipient artery 2, the location of the arteriotomy in the recipient artery 2, and the implantation. Determined by the vascular surgeon based on the lumen diameter of piece 11. The graft 11 is preferably anastomosed to the receiving artery 2 using continuous sutures 22 at the heel region 17 and the crotch angle 16 at the flanges 12, 14 bifurcating the arteriotomy.

FIG. 5 shows a perspective view of a first embodiment of the graft 10 of the present invention anastomosed to the receiving artery 2.

FIG. 6 shows various sizes and symmetric shapes of a bifurcated flange at the distal end of a tubular ePTFE graft 11 anastomosed to the receiving artery 2.

The first implant has an asymmetric bifurcated flange 30, 40, which has a larger surface area than the flange 40, wherein the flange 30 is laterally away from the implant 11, It also extends at a greater rate than the flange 40 so as to surround the flanged implant 11. The first implant crotch angle 41 is biased toward the shorter flange 40 with respect to the midline 31 of the implant 11. The shape of the first graft with the flanges 30, 40 is well suited for an end-to-side anastomosis, and the angle between the graft 11 and the receiving artery 2 is closer to the shorter flange 40 side. Beveled and obtuse on the side of the longer flange 30.

The second implant has substantially symmetrical bifurcated flanges 34, 36, the crotch angle 37 of which substantially coincides with the midline 31 of the implant 11. The flanges 34 and 26 extend substantially the same length in the opposite direction in the lateral direction relative to the implant 11 such that the distal ends around the arc of the flanges 34 and 36 are connected to the receiving artery 2. Extending to substantially equal extents around. A second graft having symmetrical bifurcated flanges 34, 36 is particularly convenient where the angle of the end-to-end anastomosis between the graft 11 and the receiving artery 2 is substantially vertical. It is.

The third implant, represented by the asymmetrically bifurcated flanges 28, 32, is substantially mirror symmetric with the first implant shown by the asymmetrically bifurcated flanges 30, 40. It is. In this third implant, the flange 32 projects laterally more than the flange 28 from the implant 11 and extends around the implant 11. The third implant crotch angle 33 is offset toward the shorter flange 28 with respect to the midline 31 of the implant 11. The shape of the third graft with flanges 28, 32 is well suited for end-to-side anastomosis, and the angle between the graft 11 and the receiving artery 2 is closer to the shorter flange 28. It is acute and obtuse on the side of the longer flange 32.

In each of the three preferred embodiments of the bifurcated flange graft 10, the bifurcated flange is preferably formed of ePTFE and has a discontinuous seam of the ePTFE tubular graft 11. A continuous and integrated cross-section without any superimposed regions is formed.

The bifurcated flange may be formed by various methods of ePTFE formation, which may include molding a portion of the ePTFE tubing, selectively expanding a portion of the ePTFE tubing, manual cutting or laser cutting, or book cutting. PCT Implant International Application co-filed with the title "Apparatus and Method for Producing an End-to-End Anastomotic Bypass Graft", which is hereby incorporated by reference to show one of many ways of making the implant of the invention. Cutting or shaping according to the improved method.

As described above, for those skilled in the art, the longitudinal axis of the inflow graft is positioned at an acute angle with respect to the receiving artery 2 and the longer flange relative to the direction of blood flow. The use of asymmetric flanges on the implant 10 with the flanges such that the distal end is directed distally and the shorter flanges are directed closer is particularly well suited for end-to-side anastomosis. It can be understood.

Dimensionally, it is preferable to assemble each bifurcated flange between 1 and 5 times the diameter of the implant lumen. Thus, the shorter flange for a 5 mm implant has a length measured from the outer surface of the implant to the furthest point of the toe region of the flange no shorter than 5 mm, and the longer flange is The length measured from the outer surface to the furthest point in the toe region of the flange must not be longer than 25 mm. Peripherally, each bifurcated flange should not be larger than one diameter of the graft lumen around the receiving artery. Thus, if the implant has a lumen diameter of 5 mm, the bifurcated flange is 5 mm, measured from the midline of the implant to the arcuate end of the circumferentially furthest flange. Must not be larger than

寸 法 Such a dimensional structure was found to exhibit optimal parameters for an ePTFE femoral-infra-genetic bypass graft that does not allow the use of vein patches or collars at the arterial junction of ePTFE. The structure of the bifurcated flange graft 10 was found to have optimal geometry and the potential for reducing intimal hyperplasia development due to the absence of the graft. The bifurcated flange graft 10 of the present invention exhibits minimal presence or swirling at the anastomosis in the region of low flow velocity, and exhibits an optimal blood flow pattern for end-to-side anastomosis.

端 Typical end-to-side anastomosis presents a complex blood flow pattern at the anastomotic junction. Regions of low flow velocity that preserve flow velocity and vortex formation are found in virtually all types of known end-to-side anastomoses. Clearly, detailed blood flow measurements are difficult to obtain in vivo. The pulsatile flow model was developed by simulating blood circulation conditions in the distal anastomosis of the subfemoral bypass graft 10 of the present invention. A closed loop of flow was formed connecting two reservoirs maintained at systolic and diastolic blood pressure. A magnetic valve was used to create a similar pulsatile flow as in the femoral artery. A blood analog stream (Dextran, 7.5% by weight in distilled water) was used. To enhance the sonographic visualization, the blood analog stream was inoculated (1 g / L) with 40-120μ of Sephadex granules (Pharmacia, Uppsala, Sweden).

Flow visualization and velocity domain measurements were performed by direct dye injection and a real-time ultrasound system with a linearly arranged transducer of 5 MHZ with a Doppler frequency of 3.5 MHZ and an aperture size of 3.8 cm (Acuson 128XP / 10 ) Was achieved by Doppler color flow measurement. Doppler color flow measurement images were recorded continuously using an S-VHS video camera and an S-VHS high resolution video cassette recorder. Images were acquired at specific intervals in the pulsation cycle using a peak capture technique that depicts the peak velocity of each pixel of the frame within successive one second intervals. The flow rate measurements were detected using an ultrasonic beam carried upstream or downstream at a 70 ° angle to the face of the transducer.

The bifurcated flange graft 10 of the present invention can be tested on Lynton and Taylor patches using dye injection and Doppler color flow measurement flow visualization techniques at both low and high pulsatile flow rates. It was done. In both Lynton and Taylor patches, the velocity profile is bent toward the outer wall of each implant, independent of the flow rate. Impact of the flow against the outer wall results in an annular flow motion at high flow conditions, whereas at low flow conditions the area where flow is stagnant is aligned with the outer wall of the main vessel and aligned with the inner wall of the implant. At this point, one flow trend moved to the distal end of the tributary and one flow trend moved to the proximal end of the tributary of the receiving artery, marking a region of remote flow. Flow vortices were observed in the toe and heel regions where the Linton and Taylor patches were observed, and minimal vortex formation was observed in the anastomotic portion of the implant 10 of the present invention. The flow profile through the bifurcated flange graft 10 of the present invention is shown in FIG.

In Doppler color flow measurements, both the Lynton and Taylor patches produced the following circulation profiles: 1) anti-vortex flow upstream and downstream diversion into forward flow: 2) jet flow and anastomosis A heterogeneous flow pattern downstream of the section; and 3) a low flow region with zero or counter flow. The initial location of each of these blood circulation events is opposite the graft inlet and along the inner wall of the artery downstream from the anastomotic toe. A change in flow pattern with a deceleration of the flow waveform from contraction to relaxation increases the low flow area of both Lynton and Taylor patches. These blood circulation phenomena were not observed to such a degree as statistically significant with the bifurcated flange graft 10 of the present invention exhibiting the laminar flow pattern substantially as shown in FIG. .

In clinical practice, 65 infra-knee bypass grafts using the bifurcated flange graft 10 of the present invention were performed on 62 patients. In 18 patients, a temporary extracorporeal bypass was used to measure blood flow and blood pressure to calculate circumferential arterial resistance in each of the upstream and downstream directions. Was inserted between. The patency of the present invention was tracked. Prior to the bypass operation, all patients underwent ankle pressure measurement and angiography with a Doppler ultrasound system. Graft patency was followed by surgical testing, and Doppler ultrasound-diagnosed arterial pressure was investigated at three-month intervals in all patients. Anastomosis morphology and structure were examined by post-operative angiography and by Doppler color flow measurement at 3 month intervals. The initial patency rate for the year was 60%, which remained constant during the second year of follow-up. The second year's patency rate for the year was 68%, while the second year's patency rate dropped to only 60%.

7 and 8, there is shown a second preferred embodiment of a bypass graft referred to as an arterial-venous patch (AVP) prosthesis 50 for identification. The arterial-venous patch prosthesis 50 generally includes a tubular ePTFE graft member 52 having an outer fluttering skirt portion 56 extending around the periphery of the tubular ePTFE graft member 52. The fluttering skirt 56 preferably has a generally elliptical shape and is offset from the central longitudinal axis 53 of the tubular ePTFE graft member 52. The deflection is such that the first focus of the elliptical fluttered skirt 56 is from the second longitudinal focus 53 of the elliptical fluttered skirt 56 from the central longitudinal axis 53 of the tubular ePTFE graft member 52. Are also provided apart.

Additionally, the fluttering skirt 56 is present on a surface 55 that is angularly biased toward the tip with respect to the central longitudinal axis 53 of the tubular ePTFE graft member 52. By biasing at an angle to the tip with respect to the central longitudinal axis 53 of the tubular ePTFE graft member 52, the fluttering skirt 56 causes the tubular ePTFE graft member 52 to have a toe angle 62 and a heel. It is formed so as to form an angle 60.

According to a preferred embodiment of the arterial-venous patch prosthesis 50, the toe angle 62 is greater than 90 ° with respect to the central longitudinal axis 53 of the tubular graft member 52, while the heel angle 60 is equal to the tubular graft member. It is less than 90 ° with respect to the longitudinal axis 53 at the center of 52. According to a preferred embodiment of the present invention, the toe angle 62 ranges from 95 ° to 160 ° with respect to the central longitudinal axis 53 of the tubular ePTFE graft member 52, while the heel angle 60 is , With respect to the central longitudinal axis 53 of the tubular ePTFE graft member 52, in the range of 20 ° to 85 °.

The fluttering skirt portion 56 has a toe portion 67 that projects outwardly from the ePTFE tubular member 52 at a toe angle 62. The length of the toe portion 67 may be predetermined during manufacture, or may be trimmed by vascular surgery during the implantation procedure to adjust to an open arteriotomy at the anastomosis. A heel portion 69 projects outwardly from the ePTFE tubular member 52 at a heel angle 60 and in a direction opposite to the toe portion 67. The curved outer peripheral end 58 of the fluttering skirt 56 forms a continuous surface that connects the toe portion 67 and the heel portion 69 against a 180 ° arc. Depending on the desired length of the toe portion 67, the curved peripheral distal end 58 and the distance 71 over which the fluttering skirt 56 protrudes distally with respect to the ePTFE tubular member 52 can be varied. The imaginary lines 64, 66 represent the other curved outer peripheral end portions 64, 66 of the fluttering skirt portion 56.

The fluttering skirt 56 is preferably formed of ePTFE and is formed as a continuous, integral, unitary piece of ePTFE tubular graft member 52 without intermediate seams or overlap.

The fluttered skirt portion 56 may be formed in various ways of forming ePTFE, which may mold a portion of the ePTFE tubing, selectively expand the portion of the ePTFE tubing, manually cut or laser cut, or PCT filed concurrently with the title "Apparatus and method for manufacturing an end-to-end anastomosis bypass graft" for reference and incorporated herein by reference to illustrate one of many methods for manufacturing the graft of the present invention. Includes cutting or shaping by the improved method of the Ipra International Application.

As shown in FIG. 8, fluttered skirt 56 has a curved shape in its z-axis to allow for a suture anastomosis between distal end 58 and around the outer shape of the artery. The fluttered skirt 56 is preferably a tubular implant of ePTFE measured from the top of the toe region 67 to a point along the distal end 58 furthest from the top of the toe region 67 of the fluttered skirt 56. It must extend a distance not greater than the diameter of the lumen of the piece 52.

According to a preferred embodiment of the AVP prosthesis 50, the toe region 67 has a greater length than the heel region 69, and the toe region 67 extends from the central longitudinal axis 53 of the tubular graft member 52 of ePTFE. It protrudes outward in the direction of blood flow. As noted above, preferably, the length of the toe region 67 is measured from the outer wall surface of the ePTFE tubular graft member 52 adjacent to the toe region 67 to the farthest point of the outer peripheral end 58 of the toe region 67, It is variable in the range of 5 to 25 mm. However, for the femoral end bypass anastomosis, maintaining the length of the heel region 69 at a fixed length of 3 mm as measured from the outer wall surface of the ePTFE tubular graft member 52 adjacent to the heel region 69 Was found to be preferable.

Although the present invention has been disclosed and described with reference to preferred embodiments thereof, those skilled in the art will recognize that changes in material selection, dimensions, and modifications may be made without departing from the scope of the invention, which is limited only by the appended claims. , And will understand and judge the structure.

FIG. 3 is a diagram illustrating the peripheral vasculature of a human leg showing an implanted femoral lower leg bypass graft. FIG. 9 is a diagram illustrating a conventional mirror cuff. FIG. 9 is a diagram illustrating a conventional tailor patch. FIG. 3 is a diagrammatic representation of a graft of the present invention for anastomosing a femoral lower leg bypass graft to a peripheral artery. 1 is a perspective view illustrating a graft of the present invention for anastomosing a femoral lower leg bypass graft to a cross-section of a peripheral vasculature. FIG. FIG. 4 is a diagram showing another structure of the bypass graft of the present invention for anastomosis of a femoral lower leg bypass graft to a peripheral artery. FIG. 4 is a diagrammatic representation of an implant of the invention for AVP bypass. FIG. 1 is a perspective view showing a bypass graft of the present invention for AVP bypass anastomosed to a cross section of a peripheral vascular structure. FIG. 3 is a diagram illustrating the shape of blood flow through a thigh tip implant of the present invention.

Explanation of reference numerals

2 ... artery, 3 ... femoral artery occlusion, 4 ... crouching artery occlusion, 5 ... mirror cuff, 7 ... tailor patch, 8 ... vein patch, 10 ... ePTFE graft, 11 ... ePTFE graft, 12,14 ... flange, 16 ... crotch angle, 17 ... heel region, 18,20 ... distal end, 19 , 21 ... toe portion, 22 ... stitching portion, 28, 30, 32, 34, 36, 40 ... flange, 31 ... intermediate line, 33, 37, 41 ... crotch angle, 50 ... arterial-venous patch prosthesis, 52 ... ePTFE graft member, 53 ... longitudinal axis, 55 ... biasing surface, 56 ... skirt, 58 ... peripheral End, 60 ... heel angle, 62 ... toe angle, 64, 66 · The distal end portion, 67 ... toe portion, 69 ... heel, 71 ... extension distance.

Claims (10)

An expanded tubular polytetrafluoroethylene implant having a proximal end and a distal end;
A flange portion made of polytetrafluoroethylene extended at the distal end of the tubular implant protruding outwardly from a central axis of the tubular implant;
A vascular graft suitable for end-to-side anastomosis, wherein the at least one flange portion is an integral part continuous with the tubular graft member. The vascular device of claim 1, wherein the expanded polytetrafluoroethylene tubular implant further comprises a reinforcing member circumferentially disposed about a longitudinal direction of the tubular implant. Graft. The vascular graft of claim 1, wherein the at least one flange portion further comprises a collar extending around the entire outer circumference of the distal end of the tubular implant. The vascular graft of claim 1, wherein the at least one flange portion further comprises two flange members protruding outwardly away from a central axis of the tubular graft member. 5. The vascular graft according to claim 4, wherein the two flange members are substantially mirror symmetric with respect to each other. The vascular graft according to claim 4, wherein the two flange members are substantially asymmetric with respect to each other. The tubular implant further comprises a first longitudinal region having a first lumen diameter, and the distal end of the tubular implant further comprises a second lumen diameter greater than the first lumen diameter. The vascular graft according to claim 1, wherein the vascular graft is provided. The first of the two flange members has a toe portion of the implant directed distally with respect to the liquid flowing through the bypass graft, and the second of the two flange members is associated with the liquid flowing through the graft. 5. The vascular graft of claim 4, having a heel portion of the graft directed to the proximal end. 9. The vascular graft according to claim 8, further comprising a crotch angle formed at a junction between the first and second flange members, wherein the crotch angle is between 45 and 180 degrees. Pieces. The vascular graft according to claim 1, wherein the first and second flange members each have a length between one and five times the lumen diameter of the expanded polytetrafluoroethylene graft member. Pieces.

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