JP2008528206A - Prosthesis with sleeve valve - Google Patents

Abstract

A pressure sensitive prosthesis (10) is disclosed that includes a tubular member (11) having a passage extending therethrough and a sleeve (13) mounted about one end of the tubular member. The sleeve functions as a one-way valve, allowing fluid to flow in the sleeve lumen in a first distal direction under a first pressure, and the pressure of the fluid flowing in the second direction in the first direction or When it exceeds that of pressure, it will collapse in response. One aspect of the present invention includes an esophageal anti-reflux expandable prosthesis where the sleeve is flipped out of the tubular stent frame to burp or vomit (fluid or material under a third high pressure). It can be so.
[Selection] FIG.

Description

  This application is a continuation-in-part of co-pending US patent application Ser. No. 10 / 208,736, filed Jul. 29, 2002, which is filed on Jun. 7, 2001. US patent application Ser. No. 09 / 876,520, filed in Japanese Patent Application No. 09 / 876,520, which was issued as US Pat. No. 6,746,489, U.S. Patent No. 6,746,489 claims priority to U.S. Provisional Patent Application No. 60 / 211,753 filed on June 14, 2000, and further, said U.S. Patent Application No. 10/208, No. 736 is a continuation-in-part of U.S. patent application Ser. No. 09 / 386,173, filed Aug. 31, 1999, the U.S. patent application Ser. No. 09 / 386,173, 917 and Are issued Te, the U.S. Pat. No. 6,302,917, which claims priority to U.S. Provisional Patent Application No. 60 / 098,542, filed Aug. 31, 1998. This application further claims priority to US Provisional Patent Application No. 60 / 309,107, filed July 31, 2001, and 60 / 648,744, filed January 31, 2005. Yes.

  The present invention relates generally to medical devices, and specifically to indwelling valve prostheses.

  An anti-reflux esophageal prosthesis or stent is usually used to maintain its patency in the lower esophagus and through the lower esophageal sphincter due to the presence of cancerous tumors commonly found near the lower esophagus Installed. The growth of a cancerous tumor generally affects the flow of food and fluid through the esophagus. Currently, in the United States, lower esophageal cancer occurs in about 12,000 patients per year. The prevalence in the United States is about 5.1 per 100,000 people, and this rate is rising, especially in white male patients. Esophageal prostheses or stents are usually used for patients with these cancerous tumors. However, these devices are not FDA approved for benign tumors that still cause esophageal obstruction or partial stenosis. Esophageal prostheses or stents are used for benign tumor cases in Europe and other countries, but are not currently used in the United States.

  A problem with esophageal prostheses or stents is that fluid from the stomach flows into the patient's mouth when the patient is prone. In an attempt to solve this problem, many esophageal prostheses or stents utilize one-way valves, such as platypus or cocoon-shaped, that allow food or fluid from the esophagus to flow into the stomach only in the antegrade or forward direction. is doing. However, there are certain problems with these unidirectional backflow prostheses or stents. For example, if a patient wants to burp or vomit, the patient cannot do so because the one-way valve prevents the retrograde flow back. This situation is not only painful for the patient but also causes more complex symptoms.

There are other anatomical sites where the prosthesis is placed to maintain a lumen that opens as a passage for bodily fluids, such as the biliary and genitourinary systems. Such a prosthesis creates undesirable pathogen retrograde flow and / or risk of transfer and can cause other problems such as infection and stent occlusion. When a drainage stent or catheter is placed across a sphincter or natural stenosis at the site of opening into the body passage, the sphincter or stenosis performs its normal function of suppressing retrograde flow or migration I can't. What is needed is a prosthesis and a one-way valve that can effectively regulate antegrade and retrograde flow in response to normal flow and pressure existing across the site where the prosthesis is installed. is there.
US patent application Ser. No. 10 / 208,736 US Pat. No. 6,746,489 US Provisional Patent Application No. 60 / 211,753 US Pat. No. 6,302,917 US Provisional Patent Application No. 60 / 098,542 US Provisional Patent Application No. 60 / 309,107 US Provisional Patent Application No. 60 / 648,744 US Pat. No. 4,580,568

  The above problem is solved by an exemplary prosthesis having a sleeve that allows forward flow through the sleeve under a first pressure and that collapses in response to a second flow or pressure greater than the first flow or pressure, Technical progress is achieved.

  In one aspect of the invention, the prosthesis has a sleeve extending from the tubular frame when the gastric pressure exceeds a given level (a third pressure greater than the second pressure). It has an anti-reflux esophageal prosthesis that is turned inside out and allows gastric gasses and vomit to flow in the retrograde direction. In the antegrade or downward position, the sleeve collapses to prevent gastric gas and fluid from flowing through the esophagus into the patient's mouth. The collapsible sleeve functions as a one-way valve, allowing the patient to ingest and pass liquids and food into the stomach. Also, this convenient anti-reflux esophageal prosthetic tubular frame maintains the patency of the lower esophagus and sphincter, specifically if, for example, cancerous tumors can interfere with fluid passage through the esophagus. Maintain patency in some cases.

  In another advantageous aspect of the present invention, the tubular frame of the anti-reflux esophageal prosthesis includes a plurality of self-expanding zigzag stents. The compressed stent, along with the sleeve, is placed in a delivery catheter that passes from the mouth through the esophagus and lower sphincter. The prosthesis is then deployed from the delivery catheter, such as with a dilator or pusher catheter that is inserted into and / or through the lumen of the delivery catheter. Once deployed, the self-expanding stent expands easily and engages the esophagus and lower sphincter to keep them patent.

  The tubular frame self-expanding stent is advantageously flared at each end of the tubular frame to prevent forward and retrograde movement of the expanded prosthesis. Further, in order to prevent the zigzag stents from moving relative to each other, filaments are arranged circumferentially through closed small holes at the bends of adjacent zigzag stents. Filaments are also advantageously used to control the radial expansion and flare morphology of stents located at each end of the tubular frame.

  The pressure required to collapse or flip the one-way valved sleeve is related to the sleeve material, its wall thickness, and the length extending from the distal end of the tubular frame. Depending on the dimensions of the human or veterinary patient anatomy, the length of the sleeve extending from the end of the frame is in the range of 0.0 cm to 20 cm, preferably in the range of 5 cm to 15 cm. More preferably, it is about 10 cm for human patients and about 8 cm for veterinary patients as derived from experiments. The sleeve material may include polyurethane, silicone, polyamide, other urethane materials, or any biocompatible material that is flexible and acid resistant. Conveniently, the material of the sleeve covering the frame itself is 0.005 to 0.01 inches thick. The sleeve extending from the end of the frame comprises a material having a thickness from 0.0015 inches to 0.01 inches including 0.01 inches. Advantageously, the length of the sleeve is made long enough so that it can be easily shortened to accommodate the individual anatomical situation.

  In yet another aspect of the present invention, the sleeve is present when symptoms of increased stomach pressure (third pressure), such as burping, are occurring and it is not necessarily physiologically important that flipping occurs. Is designed to be less prone to flipping through the tubular frame. Therefore, a part of the sleeve is modified so that it is difficult to turn it over. One example of such a modification is to spread the sleeve toward its first end (ie, the end of the sleeve away from the tubular frame) so that the sleeve is divergent or bell-shaped. . The wide first end is unlikely to turn over through the narrow tubular frame. The second modification is to add a hard area like a ring around the first end, when a third gastric pressure like burp, which is higher than the second pressure, acts on the valve. The reaction is to prevent flipping through the tubular frame and to keep the valve closed as long as there is no incoming flow (first pressure). The intention is that if the third pressure is not high enough to guarantee the flipping required for the patient's health or comfort, in particular the patient flips the sleeve over again by swallowing liquid following the onset of such symptoms. If it has to be done, flipping is to limit or prevent. The ring or stiff region of the sleeve can be a wound around the first end of the sleeve, a thickened sleeve material, or one or more rings or similar elements secured to the sleeve material. The sleeve may be made to close above or below the rigid area or ring.

  In another aspect of the invention, a collapsible sleeve is attached to the proximal end of the tubular frame and the sleeve extends distally through the tubular frame.

  In another aspect of the invention, the collapsible sleeve is attached to a tubular drainage stent, such as a biliary stent, to allow intestinal contents and related bacteria to flow back into the stent passage. Conveniently preventing. These bacteria are known to promote the formation of biofilms that cause stent occlusion. To maintain the patency of the bile duct or pancreatic duct and the papilla, when the stent is placed in the biliary system, the sleeve extends downward and enters the duodenum and opens a one-way valve for bile flow. providing. When the bile is not secreted, the sleeve is conveniently collapsed to prevent the backflow of material from the duodenum, and in this situation, if there is no closing means, the bile duct stent may have backflow of material from the duodenum. There is. Tubular drainage stent for placement in the ureter or urethra allows urine to flow, but extends from one end to prevent retrograde flow to the kidney or bladder and pathogen transfer Either the sleeve is included or the sleeve is placed completely within the lumen of the drainage stent, and one end of the sleeve is either glued or otherwise attached to the inner wall of the lumen.

  1 to 14 are representative of the present invention comprising a tubular member 11 having a passage 12 therethrough and a thin flexible sleeve 13 extending from the tubular member 11. Prosthesis. The sleeve 13 also has a passage 15 therethrough, which allows the flow of liquid or other material to move under the first pressure, but the flow and pressure drop to reduce the drainage environment. When the second back pressure exceeds this, the sleeve 13 is collapsed at that time to prevent the substance fluid from entering the tubular member.

  FIG. 1 shows an external view of an exemplary and preferred embodiment of a pressure sensitive anti-reflux esophageal prosthesis 10 of the present invention. The prosthesis includes a tubular frame 11 of a group 19 of a plurality of self-expanding zigzag wire stents 20, 21, 23, the tubular frame 11 being disposed around and extending along its entire length 27. Covered with a polyurethane sleeve 13. The sleeve also extends from the distal end 14 of the self-expanding tubular frame and has a lumen 15 extending longitudinally therethrough. The sleeve lumen 15 is in communication with the passage 12 of the tubular frame. When the prosthesis is placed in the lower esophagus and through the patient's lower sphincter, the lumen 15 of the lower portion 28 of the sleeve flows from the esophagus through it in the first direction 17 in gastric juice, fluid, or saliva Because it is wet by, it is crushed to overlap with itself. As a result, the sleeve 13 is in the collapsed position and functions as a one-way valve leading into the stomach, causing gastric juice to flow backwards, i.e., in a direction referred to herein as the second direction 18, causing the prosthesis and the esophagus to flow. To prevent it from flowing into the patient's mouth. However, fluid easily flows in the opposite (first) direction 17 from the esophagus through the one-way valve into the patient's stomach.

  Tubular frame 11 includes a group 19 of a plurality of self-expanding stents 20, 21, 23 that are interconnected circumferentially by filaments 24 near adjacent ends 25 and 26 of the stent. In this illustrated embodiment, the tubular frame includes four Gianturco type self-expanding zigzag wire metal stents described in US Pat. No. 4,580,568, which is hereby incorporated by reference. Incorporate. It should be noted that the illustrated stent structure is merely an example, and other stents and stent structures may be used instead of the illustrated stent frame.

  The tubular frame includes first and second flare stents 20 and 21 disposed at the distal end 14 and the proximal end 22 between which the first and second cylindrical stents 23 are located. Is arranged. As an example, the first and second flare stents 20 and 21 have a minimum diameter of 18 mm and a flare diameter of about 25 mm. These diameters are the nominal diameters of the stent and will be changed as appropriate to the specific requirements of the human or veterinary patient. The diameter of the flared end is maintained by the end filament 29. The minimum diameter of the flare stent is maintained by the interconnecting filament 24 along with the nominal diameter of the cylindrical stent. The interconnect and end filaments 24 and 29 are, for example, a 3/0 diameter mono-nylon suture material. The first and second flare stents 20 and 21 are positioned below and above the lower esophageal sphincter to prevent the prosthesis from moving in either the antegrade or retrograde direction with respect to the esophagus. The proximal flare stent, together with the cylindrical stent 23, expands against the tumor in the region of the lower esophagus and maintains the patency of the lower esophageal lumen.

  Flared stents 20 and 21 are formed, for example, from a commercially available series 304 stainless steel cylindrical wire having a diameter of about 0.015 inches. The wire is formed in a zigzag pattern where both ends are joined together using, for example, a metal sleeve and soldered together using silver / tin solder. However, other methods are also conceivable for forming a closed zigzag structure, such as at least a partial cylindrical shape. The flare stent has a flared or maximum diameter of about 25 mm and a minimum diameter of about 18 mm. The interconnecting cylindrical stent 23 is also formed of the same cylindrical wire and has a nominal diameter of about 18 mm, consistent with the minimum diameter of the flare stent. Individual stents are approximately 2 cm long. The overall length of the cylindrical frame is in the range of 8 cm to 14 cm, in increments of 2 cm. This incremental width of 2 cm increments is usually provided by increasing the number of interconnecting cylindrical stents 23.

  The sleeve 13 is preferably composed of a polyurethane material or other liquid-impermeable material that does not degrade in the presence of touchable fluids and other gastric substances. The sleeve is disposed around the tubular frame 11 and extends at least partially around it. The sleeve preferably extends the entire length of the frame and extends longitudinally from the distal end 14 of the tubular frame. The length of the sleeve material extending from the distal end of the tubular frame is in the range of 0 to 20 cm, preferably 5 to 15 cm, more preferably 7 to 10 cm. The length of the sleeve material can be appropriately changed by the doctor depending on the internal structure of the patient. Experimental data indicates that dogs typically use 7 cm long sleeve material. Human patients are expected to use sleeves that are 8 to 9 cm long. However, as pointed out above, the length of the sleeve can be changed by the physician to suit the particular anatomy of the patient.

The wall thickness of the sleeve material disposed around the tubular frame is about 0.006 inches to 0.01 inches. The thickness of the sleeve material along the sleeve lower portion 28 is slightly thin, for example, about 0.002 inches, but a thick sleeve of about 0.0095 inches is considered necessary for reducing patient pain. Convenient to reduce the tendency of the sleeve to turn inside out with a lower back pressure (e.g., burp) than is possible. The sleeve material preferably includes a medical grade polyurethane material, but silicone, nylon, other polyamides such as urethane, or other biocompatible materials that are flexible and acid resistant are also suitable materials. is there. In the particular embodiment shown here, the sleeve material is a medical grade polyurethane material grade EG-80A material commercially known as TECOFLEX® polyurethane material from Thermedics, Inc. of Woburn, Massachusetts. is there.

  FIG. 2 shows an enlarged cross-sectional view of the sleeve 13 around the cylindrical wire 30 of the flare stent 20 along the line 2-2 of FIG. For the illustrated embodiment, the thickness of the sleeve material is about 0.006 inches, but the thickness under the sleeve material, ie along the distal portion 28, is preferably about 0.002 inches. The thickness of the sleeve material above the distal portion 28 is in the range of 0.005 inches to 0.01 inches. Experimental data shows that the sleeve material along the distal portion 28 still collapses even with a wall thickness of 0.01 inches, effectively forming a one-way valve. However, the one-way valve material is most reliable at 0.004 inches or less because it is not guaranteed every time that a sleeve with a thickness greater than the above dimensions will cause closure. is there. However, if the desired objective is to limit the tendency of the sleeve to flip over the tubular frame 11, a thicker sleeve (0.004 inches to 0.01 inches) is desirable. If the thickness of the sleeve wall material is less than 0.0015 inches, tear problems may occur, particularly when the prosthesis is inserted into the delivery catheter.

  FIG. 3 shows an enlarged partial cross-sectional view of adjacent ends 25 and 26 of the interconnecting stents 20 and 23 of FIG. The bend 31 of the cylindrical wire 30 is formed in a keyhole shape, and an opening or small hole 33 is formed by interconnecting wire arms with silver solder 32. Interconnecting filaments 24 are placed through each eye and wound at least once to help fix the diameter of the expandable stent. At the end of each stent, one interconnect or end filament is used, and the free ends are tied to form a suture knot 34.

  FIG. 4 shows a two-part mandrel 35 used to apply the sleeve material 13 to the prosthesis of FIG. The mandrel includes a sleeve portion 36 and an upper frame portion 37, both of which can be interconnected by, for example, a threaded rod 38 and a female threaded hole 39. In use, a tubular frame that includes a plurality of self-expanding wire stents is placed end-to-end using interconnecting filaments 24. Furthermore, end filaments are arranged to constrain their maximum diameter through the flare stent eyelet. The mandrel has a minimum inner diameter that matches the inner stent inner diameter and a flare diameter that matches the flare stent diameter. The portion of the mandrel extending from the end of the flared portion is the inner diameter of the one-way valve sleeve material. The assembled tubular frame is disposed between the upper frame portions of the mandrel sleeve portion. The two parts of the mandrel are then connected to each other, thereby filling the passage of the tubular frame. The tubular frame is then dipped in a polyurethane slurry to form an initial wall thickness of 0.004 inches over the entire length of the tubular frame. The mandrel and coated tubular frame is then dipped into the slurry liquid at least once more to form the desired sleeve material thickness over the sleeve portion 36 of the mandrel. After the slurry has hardened, the two parts of the mandrel are disconnected from each other, creating a backflow prevention esophageal prosthesis.

  FIG. 5 shows the esophageal prosthesis 10 deployed in the lower esophagus 40, specifically through the lower esophageal sphincter 41 and the cancerous tumor 42. The distal flare stent 20 typically extends into the stomach with the sleeve 13. Flared stent 21 is placed proximal to the sphincter and tumor, while the interconnected cylindrical stent is typically placed through the sphincter and tumor. Flared stents 20 and 21 prevent the prosthesis from moving within the esophagus. The lower or distal portion 28 of the sleeve 13 extends into the stomach 43. The lumen of the lower sleeve portion is easily collapsed when it comes into contact with fluid flowing from the outside. However, any fluid or food easily passes in the antegrade direction through the esophageal stent and into the stomach. As a result, the one-way valve sleeve 13 opens to provide a forward flow. Conversely, because the lumen of the sleeve 13 is collapsed, any fluid or food 44 is prevented from flowing in the retrograde direction. However, when the gas or fluid pressure in the stomach increases and the patient wants to burp or vomit, the sleeve 13 stretches backwards through the lumen of the tubular frame, as indicated by phantom line 45. . In this position, gastric juice and gastric material flow in the retrograde direction, releasing the patient from pain. The length of the distal portion 28 of the sleeve and its thickness controls the pressure at which the distal portion of the sleeve is flipped through the tubular frame.

Self-expanding esophageal prostheses are increasingly used to relieve malignant dysphagia. However, these devices, when deployed across the gastroesophageal junction, make the patient more susceptible to significant gastroesophageal reflux, including the risk of foreign body suction into the bronchi. A study was conducted to evaluate the backflow prevention effect of the esophageal prosthesis of the present invention to prevent backflow. Wilson-Cook, Salem, North Carolina
Inc. A model EZS21-8 (16 mm diameter), commercially available from, was modified by extending its polyurethane coating 7 cm beyond its distal metal cage to form a sleeve that could be “blown” or crushed. The pressure required to flip the sleeve that can be blown or crushed into the tubular frame (backflow barrier) is such that the proximal end of the prosthesis is attached to a hollow memory tube and the stent is blown in the presence of water. Determined by inserting vertically until flipped. The pressure required to return the lumen that can be blown or collapsed to its original unidirectional position was then determined by pouring water into the lumen of the prosthesis. In vivo evaluation was performed on two dogs (18 kg male, 16 kg female) that had undergone esophagectomy. Prosthesis insertion, placement, and removal were performed by standard endoscopic and fluoroscopic techniques. Two-site portable esophageal pH monitoring (Synoptics
Medical) was performed 5-10 cm above the gastroesophageal function. Each dog was examined twice using the standard model EZS201-8 prosthesis and twice using the modified prosthesis (the average recording time per session was 18.7 +/- 1 SE and 17 + /, respectively). -3 hours). The results showed that the windsock correction did not pose any difficulty to the installation and deployment of the prosthesis using currently available delivery systems. The resistance to antegrade flow is minimal, and regardless of the type of prosthesis used, even a single drop of water in the prosthesis can easily pass the streamer, and both dogs will receive the given EMSURE ( (Registered Trademark) (4 cans per session) were all drunk. The pressure (cm) of water to overcome the backflow barrier is 15.7 +/− 0.3 SE, and the pressure to restore the inverted blown or collapsible lumen is 0.4 +/− 0. 03SE. The results of pH monitoring (average +/− SE) are shown in Table 1.

  The conclusion reached in the experiment is that the modified self-expanding metal esophageal prosthesis is very effective in preventing reflux. The ability of the luminal sleeve 13 to be able to be blown or crushed is to flip it over with a high pressure gradient and allow the patient to burp or vomit. The return to the backflow prevention position requires minimal pressure and is accomplished by swallowing water. The results of further studies are presented in FIGS.

  FIG. 6 shows the anti-reflux esophageal prosthesis 10 of FIG. 1 in a collapsed state within the delivery catheter 46. A sleeve material 13 is disposed at the distal end of the delivery catheter. The prosthesis is pulled into the delivery catheter with a drawstring attached to the proximal end of the prosthesis. The pull string and prosthesis are inserted through the lumen 47 of the catheter by collapsing the tubular frame and then pulling the prosthesis with the pull string to the distal end of the delivery catheter. To deploy the collapsed prosthesis from the delivery catheter, pusher catheter 48 is placed proximal of lumen 47 and engaged with the proximal end of wire tubular frame 11.

  FIG. 7 shows the delivery catheter 46 of FIG. 6 positioned adjacent to the tumor 42 in the patient's lower esophagus 40 and sphincter. The distal end of the delivery catheter extends into the stomach 43. As shown, a pusher is placed in the lumen of the delivery catheter and engages the proximal end of the prosthesis 10. As shown, a sleeve 13 and a flared distal stent 20 are deployed from the distal end of the catheter. After the prosthesis sleeve and distal flare stent 20 are deployed, the delivery catheter is partially withdrawn so that the flare stent engages around the sphincter of the stomach neck. Once deployed, the delivery catheter is withdrawn while maintaining the pusher in place, and the central cylindrical stent and proximal flare stent are released to press the sphincter, tumor, and lower esophagus. The

In vitro and in vivo evaluation of the modified self-expanding metal artificial esophageal stent with the backflow prevention mechanism of the present invention was performed in multiple dogs. The evaluation included 4 dogs, 2 of which were males 14 kg and 18 kg and 2 were females 14 kg and 16 kg. Esophagectomy was performed using an upper gastrointestinal endoscope. For evaluation, Gastrograph
Inc. And a portable pH monitoring method using Synthetics medical devices at 5 cm and 10 cm locations. The EMSURE® liquid diet at pH 6.5 was administered. The results of each method employed are shown in Table 2.

  FIG. 8 shows an in vitro reflux barrier curve 48 that represents the centimeter of water column height required to flip a given sleeve length extending from the distal end of the prosthesis. A square median box 49 represents the median water column height at the displayed sleeve length. A vertical bar 50 arranged with a square median box 49 on the curve 48 represents the standard deviation above and below the displayed median. The number of reflux symptoms was monitored at the distal and proximal ends of the prosthesis. For a standard prosthesis without a one-way valve, the number of reflux episodes was 197 after 250 trials. At the proximal end of a standard tubular esophageal prosthesis, the number of reflux episodes was observed for a total of 33 times with 50 trials. In contrast, the distal end of the anti-reflux esophageal prosthesis of the present invention was observed only 16 times after 250 trials. At the proximal end of the anti-reflux esophageal prosthesis, only 8 out of 50 trials were observed. The number of reflux symptoms exceeding 5 minutes was also observed. With a standard prosthesis, 19.8 episodes were recorded in 25 trials. This is in contrast to the number of symptom occurrences of 0.3 in the anti-reflux esophageal stent of the present invention. At the proximal end of the prosthesis, the number of symptom episodes lasting more than 5 minutes was observed 2.3 times in 3 trials, whereas never on the backflow prevention prosthesis. The onset of longest reflux symptoms was also observed at the distal and proximal ends of standard and anti-reflux prostheses. At the distal end, 107 out of approximately 130 trials were observed with the standard prosthesis, while only 3.8 were observed with the anti-reflux prosthesis. At the proximal end of the prosthesis, 39 manifestations were observed in 45 trials with the standard prosthesis, but only 1.8 with the anti-reflux prosthesis.

  FIG. 9 shows the fractional time percentage at which the esophagus is exposed to gastric fluid below pH 4. At the distal end of the prosthesis, the fractionation time percentage is indicated by box 51 for the distal end of a standard prosthesis of 4 dogs. Their percent fractionation times range from 20% to 80% and the median is 49%. For a backflow prevention prosthesis, the fractionation time percentage is in the range of 0.0% to about 1.5%, as shown by box 52, with a median of 1%. The p value at these fractionation times is 0.026.

  FIG. 10 shows the fractional time percentage of the proximal end of a standard and anti-reflux prosthesis. Box 53 shows the percent fractionation time for a standard prosthesis, ranging from about 4% to 14%, with a median of 6.6%. Square box 54 represents the percent fractionation time for a backflow prevention prosthesis and is in the range of about 0.0% to 1.0%. Their p value is 0.055.

  The conclusions obtained from this in vitro and in vivo evaluation are as follows. The modified self-expanding metal esophageal prosthetic stent of the present invention exhibits an excellent effect in preventing gastroesophageal reflux. The modified ability to turn inside out during high pressure gradients allows burping and vomiting. Once turned over, minimal pressure is required to return the prosthesis to the backflow prevention position, which is accomplished by swallowing water.

  A related esophageal prosthesis embodiment of the present invention is shown in FIG. 17, but a portion of the collapsible sleeve 13 is turned over through the tubular frame in response to a third pressure, such as a burp. It comes to resist. In the illustrated example, at least a portion of the sleeve has a second end 68 (a plurality of expandable stents) toward the first end 67 such that the sleeve 13 is flared, tapered, conical, or bell-shaped. The width of the joint portion with the end portion 14 of the tubular frame 11 provided with 19 is wider than the end portion of the portion that can be crushed. In other words, the surface of the portion of the sleeve 13 extending between the first end 67 and the second end 68 is straight, convex, as long as the first end 67 is wider than the second end 68. It may be concave or any combination of these shapes. In the illustrated embodiment, the width of the second end 68 is about 25 mm. From this point, the diameter of the sleeve increases until it reaches about 31 mm at the first end 67. The widened first end 67 helps to prevent the collapsible sleeve 13 from turning over through the tubular frame. As explained above, to flip a collapsible sleeve, it is then necessary for the patient to drink water and flip the sleeve back to the anti-reflux position.

  The second modification of the embodiment of FIG. 17 aimed at preventing the collapsible sleeve 13 from being flipped into the frame 11 is the illustrated ring at the first end 67 of the sleeve 13. This is a thick or hard region 80. Two or more rings may be arranged, and the one or more thick regions 80 may be configured in various non-annular shapes. The rigid ring 80 can be comprised of a sleeve wound around the first end 67, a thick edge formed by adding sleeve material, or a ring of material affixed to the sleeve. It provides rigidity and reduces the possibility of turning inside out in situations where it is not desirable or necessary to turn over. By adding any of the above modifications, the sleeve material can be thinned to create a better seal against the normal back pressure of the fluid. For example, a sleeve 13 having a thickness of 0.004 inches or 0.005 inches will collapse more easily, but with back pressure that does not really require flipping to release or exhale the stomach pressure in question. Sometimes, it may be turned inside out through the stent, so the patient needs to drink a full liquid to turn the sleeve over again.

  Reversing through the tubular frame 11 should be a relatively rare event, and in certain patients, such as those who have undergone Nissen Fundation, the ability to burp or vomit May be unnecessary because is very weak. In order to solve the problem of inappropriate flipping, the sleeve has a thickness of about 0.0095 inches, making it difficult to flip through the frame. Thickened sleeves are difficult to turn over again, but are not optimal valves. Thus, enlarging the distal side of the ring 80 and / or the sleeve 12 represents another way to solve the flip-over problem. In the illustrated modification, the sleeve can be made even shorter (eg, less than 8 cm) and still maintain desirable valve characteristics.

  Note that the inside-out prevention structure shown in FIG. 17 can also be used for other types of stents and prostheses installed elsewhere in the body to function as a valve. For example, the anti-inversion structure can be used for a tubular drainage stent of the type described below.

  18 and 19 show an embodiment of a pressure sensitive anti-reflux esophageal prosthesis with a collapsible sleeve 13 extending distally from the proximal end 22 of the tubular frame. As shown in FIGS. 18 and 19, the prosthesis includes a tubular frame 11 of a group 19 of a plurality of self-expanding zigzag wire stents 20, 21, 23. The tubular frame 11 includes a proximal end 22 and a distal end 14. The sleeve 13 is attached to the proximal end 22 rather than the distal end 14.

  As shown in FIG. 18, the sleeve 13 extends distally through the passage 12 of the tubular frame. Specifically, the sleeve extends distally through a portion of the length of the passage 12. The sleeve 13 can be flipped (shown as a flipped sleeve 113). The sleeve may be shorter or longer in length. For example, the sleeve may be longer, shorter or equal than the axial length of the tubular frame. The embodiment shown in FIG. 18 includes a sleeve that is shorter than the tubular frame.

  The use of a sleeve shorter than the tubular frame is particularly suitable for use in patients suffering from hiatal hernia. In patients with hiatal hernia, esophageal compression is often seen at the esophageal junction adjacent to the diaphragm. This compression is severe enough in some circumstances to squeeze or pinch the sleeve valve and possibly prevent overturning. However, in the embodiment of FIG. 18, the sleeve is protected from such compression or pinching because its entire length is located within a tubular member that traverses the problematic esophageal joint.

  The embodiment shown in FIG. 19 includes a sleeve that is longer than the tubular frame 11. As shown, the sleeve 13 can be flipped (shown as a flipped sleeve 113) and extend proximally from the proximal end 22 of the tubular frame. This allows the patient to vomit or burp if necessary, as described above. As described above with respect to the previous embodiment, the patient can return the sleeve to its normal first configuration, for example, by drinking water.

  The prosthesis 10 shown in FIGS. 18 and 19 can also be provided with the inside-out prevention structure shown in FIG. For example, as described in detail above, the sleeve 13 may be provided with a ring, a bell-shaped portion, a portion having a different thickness or hardness, and the like.

In yet another embodiment of the invention shown in FIGS. 11-14, the prosthesis 10 and the tubular member 11 have a first end 62 for drainage into a duct, blood vessel, organ, etc., and a first antegrade. A tubular drainage stent 60 is provided having a pressure and a second end 63 that receives fluid or other material moving in direction 17. Generally defined, a tubular drainage stent (or tubular drainage catheter) is usually placed in a body passage such as the common bile duct, pancreatic duct, urethra, etc., and is an elongated closed tubular tube that facilitates fluid flow therethrough. A conduit (usually plastic or metal). This is normally non-expandable, unlike the wire or open frame stents of FIGS. This is usually placed to either establish or maintain the patency of the body passage or to drain an organ or fluid source such as the gallbladder or bladder. The tubular drainage stent further includes retaining means 64, 65 such as flaps, barbs, pigtail loops, etc. at one or more ends 62,63. Tubular drainage stent 60 is attached to collapsible sleeve 13, which acts as a one-way valve to prevent retrograde flow 18 therethrough. The first end 67 of the sleeve is kept open when the fluid or material passing through the sleeve is presenting a pressure associated with the normal forward flow 17. When the forward flow 17 stops or decreases and the second fluid pressure 18 generated in the environment in which the fluid is discharged becomes higher than the first pressure of the forward flow 17, the first end 67 collapses and closes. In the illustrated biliary stent embodiment, bile can flow into the duodenum. However, the sleeve 13 closes when there is no measurable flow 17 and prevents the contents of the intestinal tract, now at the second high pressure 18, from entering the stent passage. The sleeve 13 is made of a material having biocompatibility that does not deteriorate even when installed in a specific environment in the human body to be installed. Materials that can be used include polytetrafluoroethylene (ePTFE), polyurethane, silicone, nylon, polyamides such as other urethanes, or other biocompatible materials. It is important that the sleeve material is properly selected. For example, in the illustrated embodiment, the sleeve is typically formed from a 2 to 3 cm section of ePTFE that is more resistant to corrosive bile than a polyurethane sleeve. The ePTFE tube is extruded into a thin walled tube that can be crushed and has enough flexibility to be sealed to prevent fluid ingress, while at the same time being integrity enough to prevent tearing. The general range of sleeve thicknesses for the illustrated embodiment is 0.001 inches to 0.01 inches, more preferably 0.002 inches to 0.005 inches (eg, 0.0025). Is the thickness. The second end 68 of the sleeve is ST-2.
SOEHENDRA TANNENBAUM® stent, COTTON-LEUNG® stent, or COTTON-HUIBREGTSE® stent (Wilson-Cook, Winston-Salem, NC)
Medical Inc. ) Around a first end 62 of a biliary stent 60 with attachment means 66, such as the crimped metal strip shown. The band 66 may be radiopaque in order to function as a fluoroscopic marker. Other attachment methods include suture bonding, selected medical grade adhesives, or thermal bonding, if appropriate for both sleeve and stent polymers.

  An alternative method for forming the sleeve of the tubular drainage stent 60 is shown in FIG. Rather than attaching a separately extruded or pre-formed sleeve 13 to the tubular member 11, in this embodiment, the wall of the tubular member made of polyethylene is the first of the tubular drainage stent 60. Thin from the end 62 in the distal direction, the sleeve 13 is integrated with the tubular member 11. There is a transition zone 77 between the tubular drainage stent 60 at the first end and the second end 68 of the sleeve 13 beyond which the sleeve 13 is in the absence of a bile-like antegrade flow 17. Thin enough to collapse to the closed position.

  FIG. 13 shows how the illustrated embodiment can be used in the common bile duct 69 to allow drainage to flow across the papilla 70 into the duodenum 71. The biliary stent 60 is placed in the normal manner inside the common bile duct 69 with the first end 62 of the stent extending out of the bile duct and the papilla 70. The first retaining means 64 abuts the sphincter opening to prevent the stent 60 from entering the conduit, while the second retaining means 65 disposed around the second end 63 includes the conduit Of the stent 60 to prevent the stent 60 from moving outward. The sleeve 13 is completely within the duodenum where it functions as a one-way valve to prevent intestinal contents from entering the biliary stent 60. Unlike the embodiment of FIG. 1, the sleeve 13 is not normally found in the presence of a third reasonably high pressure, ie, inside the duodenum, or belching or vomiting requires such a function. It is not designed to be turned upside down through the tubular member 13 even in clinically necessary situations as in the case of the esophagus embodiment. Accordingly, it may be desirable to incorporate one or more of the inside-out prevention structures shown in FIG.

  The installation of the embodiment of FIGS. 11 and 12 is performed in a system as shown in FIG. The biliary stent 60 is mounted on a guide catheter 73 that is extrapolated to a standard bile duct replacement wire guide 74 and fed into the bile duct. When deploying the stent from the guide catheter 73, the pusher element 72 is used to bring the distal end 75 of the pusher into contact with the first end 62 of the stent 60 and push forward until deployment occurs. The sleeve 13 is normally folded in an accordion style prior to deployment, and returns to an elongated configuration when the prosthesis 10 is properly positioned.

  FIG. 15 shows the prosthesis 10 with a tubular drainage stent 60 designed to be placed in the urinary system, such as in the ureter between the kidney and bladder. The sleeve 13 is attached to a first end 62 of the tubular stent 60 that includes first retaining means 64 with a pigtail shape 79. For ureteral stents, the pigtail 79 is placed in the bladder to prevent stent movement. Optionally, pigtail feature 79 is used to draw the second end of the stent (not shown), usually within the renal pelvis and ureter transition. The pigtail feature is an example of a wide variety of well-known pigtail ureters and urethral stents.

  FIG. 16 shows a tubular drainage stent 60 in which the first end 68 of the sleeve 13 is fully secured within the lumen 12 of the stent 60 and the attachment 66 is a thermal bond, adhesive, or sleeve. 13 well known means such as a ring of material capable of securing 13 material to the inner wall 78 of the stent 60. In the illustrated embodiment, the sleeve 13 is disposed entirely within the lumen 12 so as not to extend beyond the end of the tubular drainage stent 12. This is particularly useful with urethral stents to prevent pathogens from moving through the stent to the bladder while allowing urine 17 to flow in the antegrade direction. Extending the sleeve 13 out of the urethra is not very acceptable from a clinical and patient point of view.

  As in the embodiments of FIGS. 11-16, the sleeve is formed so that it has excellent flexibility and can be easily crushed so that the fluid (air or body fluid) is at the second pressure. In the second direction 18 and at least substantially close the sleeve lumen 15 to significantly reduce retrograde movement of the fluid, substance or pathogen or simply apply the first pressure in the first direction 17. It is important to ensure that the sleeve is normally in a closed state either by the absence of fluid. In a preferred embodiment, the thin polymeric material cannot maintain its normal tubular form against gravity, so the sleeve 13 does not maintain its normal tubular form (possibly unless suspended straight down). . Rather, the sleeve collapses to a closed configuration, either due to the material sticking to itself, especially when wet, or due to atmospheric or fluid pressure in the second direction 18 which usually makes the sleeve easier to close. To form a one-way valve.

  It should be understood that the anti-reflux esophagus, bile duct, urinary prosthesis 10 described above is merely an exemplary embodiment of the present invention. The present invention may include other devices, and those skilled in the art will be able to devise methods of making and using them without departing from the spirit and scope of the present invention. It should be understood that the present invention also includes embodiments that include and are comprised of the disclosed components. For example, in an esophagus embodiment, it is conceivable that only a portion of the tubular frame need be coated with a sleeve material. Further, the sleeve material extending from the tubular frame may be formed of a different material than the material covering the tubular frame. The materials for self-expanding stents are nickel titanium alloys, commercially known as Nitinol, spring steel, and other spring-like materials formed to take the form of flexible self-expanding zigzag stents. You may form with such other materials.

1 shows an external view of an illustrative embodiment of a pressure sensitive anti-reflux esophageal prosthesis of the present invention. FIG. FIG. 2 shows an enlarged cross-sectional view of the sleeve around the flared stent tubular wire of the esophageal prosthesis along line 2-2 of FIG. FIG. 2 shows an enlarged partial cross-sectional view of adjacent ends of the interconnected stent of the prosthesis of FIG. 1. Figure 2 shows a two-part mandrel used to apply a sleeve material to the prosthesis of Figure 1; 2 shows the esophageal prosthesis of FIG. 1 deployed through a patient's lower esophagus, specifically the lower esophageal sphincter and a cancerous tumor. FIG. 2 illustrates a collapsed state of the anti-reflux esophageal prosthesis of FIG. 1 within a delivery catheter. FIG. 7 shows the delivery catheter of FIG. 6 placed in the patient's lower esophagus, sphincter, and tumor. FIG. 3 shows an in vitro barrier reflux curve for the anti-reflux esophageal prosthesis of the present invention. FIG. Figure 3 shows the percent fractionation time for standard and anti-reflux prostheses used in the evaluation of the present invention. Figure 3 shows the percent fractionation time for standard and anti-reflux prostheses used in the evaluation of the present invention. 1 shows an external view of an embodiment of a tubular drainage prosthesis of the present invention. Figure 3 shows a cross-sectional view of a second embodiment of a tubular drainage prosthesis. FIG. 12 shows the prosthesis of FIG. 11 placed in the patient's common bile duct. FIG. 12 shows a side view of the prosthesis of FIG. 11 attached to a delivery system. FIG. 5 shows a side view of one end of a valve prosthesis that includes a pigtail feature. FIG. 4 shows a side cross-sectional view of a valved prosthesis with a sleeve secured to the lumen. FIG. 3 shows an external view of a second embodiment of the pressure-sensitive backflow prevention esophageal prosthesis of the present invention. FIG. 6 shows an external view of a third embodiment of the pressure-sensitive backflow prevention esophageal prosthesis of the present invention. FIG. 9 shows an external view of a fourth embodiment of the pressure-sensitive backflow prevention esophageal prosthesis of the present invention.

Claims (23)

In a prosthesis for installation in a patient,
A tubular frame having a proximal portion, a distal portion, and a passage extending longitudinally therethrough;
A sleeve extending from the proximal portion of the tubular frame and having a lumen extending longitudinally therethrough to a fluid that applies a first pressure in the first distal direction to the sleeve In response, in response to the fluid allowing the fluid to flow through the lumen in the first direction and applying a second pressure to the sleeve in a second proximal direction, A prosthesis comprising a sleeve that can be collapsed to close.   The prosthesis of claim 1, wherein the sleeve extends through the passage of the tubular frame in response to the fluid applying the first pressure to the sleeve in the first distal direction.   The prosthesis of claim 2, wherein the sleeve extends proximally from the tubular frame in response to a fluid applying a third pressure that is higher than the first pressure.   4. The tubular frame according to claim 1, wherein the tubular frame has an axial length, and the sleeve has an axial length that is longer than the axial length of the tubular frame. Prosthesis.   4. The tubular frame according to any one of claims 1 to 3, wherein the tubular frame has an axial length, and the sleeve has an axial length that is shorter than the axial length of the tubular frame. Prosthesis.   4. The tubular frame according to any one of claims 1 to 3, wherein the tubular frame has an axial length and the sleeve has an axial length equal to the axial length of the tubular frame. Prosthesis.   The prosthesis according to any of claims 4 to 6, wherein the axial length of the tubular frame is between about 8 cm and 14 cm.   The prosthesis according to any of claims 1 to 7, wherein the tubular frame comprises a plurality of stents disposed along the tubular frame.   The prosthesis of claim 8, wherein the plurality of stents are self-expanding.   The prosthesis according to claim 8 or 9, wherein at least one of the plurality of stents is flared.   The prosthesis according to any of claims 8 to 10, wherein at least one of the plurality of stents is a zigzag stent.   The prosthesis according to any of claims 1 to 11, wherein the sleeve is formed of a polymer material.   The prosthesis according to claim 12, wherein the polymeric material is polyurethane.   13. The prosthesis according to claim 12, wherein the polymeric material is selected from the group consisting of polyurethane, silicone, polyamide, expanded polytetrafluoroethylene, or any biocompatible material that is flexible and acid resistant.   The prosthesis of claim 1, wherein the sleeve has an axial length between about 0 cm and 20 cm.   The sleeve has a proximal portion having a first thickness and a distal portion having a second thickness, the second thickness being greater than the first thickness. Item 16. The prosthesis according to any one of Items 1 to 15.   The prosthesis according to any of claims 1 to 15, wherein the sleeve has a uniform thickness.   18. A prosthesis according to any of claims 1 to 15 or 17, wherein the sleeve is between about 0.0015 inches and 0.004 inches in thickness.   The prosthesis according to any one of claims 1 to 18, wherein the sleeve includes an inside-out prevention means.   The prosthesis according to claim 19, wherein the inside-out prevention means includes a bell-shaped portion.   The prosthesis according to claim 19, wherein the inside out restraining means comprises a conical portion.   20. A prosthesis according to claim 19, wherein the flip-in restraining means comprises a ring disposed around a portion of the sleeve.   The prosthesis according to claim 19, wherein the reverse-inhibiting means includes a sleeve portion having a thick material.

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