WO2006048853A1 - A gastronomy tube placement device - Google Patents

A gastronomy tube placement device Download PDF

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Publication number
WO2006048853A1
WO2006048853A1 PCT/IE2005/000124 IE2005000124W WO2006048853A1 WO 2006048853 A1 WO2006048853 A1 WO 2006048853A1 IE 2005000124 W IE2005000124 W IE 2005000124W WO 2006048853 A1 WO2006048853 A1 WO 2006048853A1
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WO
WIPO (PCT)
Prior art keywords
cage
configurable
tube
gastronomy
flexible delivery
Prior art date
Application number
PCT/IE2005/000124
Other languages
French (fr)
Inventor
Colin Patrick Cantwell
John Gerard Murray
Original Assignee
Colin Patrick Cantwell
John Gerard Murray
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Colin Patrick Cantwell, John Gerard Murray filed Critical Colin Patrick Cantwell
Publication of WO2006048853A1 publication Critical patent/WO2006048853A1/en

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Classifications

    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/34—Trocars; Puncturing needles
    • A61B17/3415—Trocars; Puncturing needles for introducing tubes or catheters, e.g. gastrostomy tubes, drain catheters
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61J—CONTAINERS SPECIALLY ADAPTED FOR MEDICAL OR PHARMACEUTICAL PURPOSES; DEVICES OR METHODS SPECIALLY ADAPTED FOR BRINGING PHARMACEUTICAL PRODUCTS INTO PARTICULAR PHYSICAL OR ADMINISTERING FORMS; DEVICES FOR ADMINISTERING FOOD OR MEDICINES ORALLY; BABY COMFORTERS; DEVICES FOR RECEIVING SPITTLE
    • A61J15/00—Feeding-tubes for therapeutic purposes
    • A61J15/0015—Gastrostomy feeding-tubes
    • A61J15/0019—Gastrostomy feeding-tubes inserted by using a pull-wire
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61J—CONTAINERS SPECIALLY ADAPTED FOR MEDICAL OR PHARMACEUTICAL PURPOSES; DEVICES OR METHODS SPECIALLY ADAPTED FOR BRINGING PHARMACEUTICAL PRODUCTS INTO PARTICULAR PHYSICAL OR ADMINISTERING FORMS; DEVICES FOR ADMINISTERING FOOD OR MEDICINES ORALLY; BABY COMFORTERS; DEVICES FOR RECEIVING SPITTLE
    • A61J15/00—Feeding-tubes for therapeutic purposes
    • A61J15/0026—Parts, details or accessories for feeding-tubes
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/22—Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for
    • A61B17/221—Gripping devices in the form of loops or baskets for gripping calculi or similar types of obstructions
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/22—Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for
    • A61B17/22031—Gripping instruments, e.g. forceps, for removing or smashing calculi
    • A61B2017/22035—Gripping instruments, e.g. forceps, for removing or smashing calculi for retrieving or repositioning foreign objects
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B17/00—Surgical instruments, devices or methods, e.g. tourniquets
    • A61B17/22—Implements for squeezing-off ulcers or the like on the inside of inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; Calculus removers; Calculus smashing apparatus; Apparatus for removing obstructions in blood vessels, not otherwise provided for
    • A61B17/221—Gripping devices in the form of loops or baskets for gripping calculi or similar types of obstructions
    • A61B2017/2212—Gripping devices in the form of loops or baskets for gripping calculi or similar types of obstructions having a closed distal end, e.g. a loop
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B90/00—Instruments, implements or accessories specially adapted for surgery or diagnosis and not covered by any of the groups A61B1/00 - A61B50/00, e.g. for luxation treatment or for protecting wound edges
    • A61B90/06—Measuring instruments not otherwise provided for
    • A61B2090/061—Measuring instruments not otherwise provided for for measuring dimensions, e.g. length

Definitions

  • This invention relates to a gastronomy tube placement device and a method of placement of a gastronomy tube.
  • a gastronomy tube is typically inserted into patients that are undergoing severe difficulty swallowing such as those patients suffering from cancer of the oesophagus or in patients unable to feed themselves such as in the case of stroke victims or Alzheimer sufferers.
  • the gastronomy tube provides a direct feeding passageway to the patient through the stomach wall and is a highly effective way of feeding a patient unable to fulfil their own nutritional needs orally.
  • the "push” technique comprises inserting a nasogastric or orogastric air tube through the patient's nose or mouth respectively and thereafter guiding the air tube down the patient's oesophagus into their stomach. Air is then pumped through the air tube until the stomach is distended. Once the stomach has been fully distended, two or four suture devices are punctured into the stomach and sutured to the skin of the abdomen to hold the stomach wall to the anterior abdominal wall.
  • the stomach is then punctured with a cannula and a wire is inserted into the stomach.
  • the tract of the wire is gradually dilated using plastic tubes until a large gastronomy tube is placed over the wire, through the anterior abdominal wall and secured in place.
  • Pull Another technique that is used for the placement of gastronomy tubes is the so-called “pull” technique.
  • This technique involves the use of an endoscope.
  • the “pull” technique entails sedating the patient and feeding an endoscope through the patient's mouth until the tip of the endoscope enters the stomach. Once in place, air is fed through the endoscope until the patient's stomach is distended and a light source located at the tip of the endoscope is turned on and shone upon the abdomen of the patient.
  • the physician locates the tip by viewing the light source shining on the patient's abdominal wall and thereafter, the physician inserts a needle through the patient's abdomen into the stomach in the vicinity of the endoscope's tip.
  • a length of wire is then fed through the needle and grasped by a gripping member of the endoscope.
  • the endoscope is then withdrawn from the patients stomach which in turn pulls the wire through the patient's stomach up through the oesophagus and out through their mouth.
  • Sufficient wire is used so that the wire is not pulled fully through the needle in the patient's abdomen.
  • the end of the wire caught in the gripping member is then released from the gripping member and that free end of the wire is tied to a gastronomy tube using a suitable knot.
  • the gastronomy tube, now attached to the wire is pulled through the patient's mouth, down their oesophagus and into their stomach by pulling on the other end of the guide wire protruding from the needle in the patient's abdomen.
  • the gastronomy tube is then pulled partially through the patient's stomach wall and secured in place.
  • the "pull” technique obviates the need to suture the patient's stomach wall to their anterior abdominal wall. As sutures do not have to be used, this decreases the possibility of inflammation and infection around the gastronomy tube and further obviates the need for a medical practitioner to spend time applying the sutures. Therefore, this "pull” method is seen as a quick and efficient technique for inserting a gastronomy tube that reduces the chances of infection and inflammation in the patient. There are, however, several drawbacks associated with the "pull” technique of placing a gastronomy tube described above.
  • a gastronomy tube placement device comprising a flexible delivery tube and a snare housed substantially within the flexible delivery tube, the snare further comprising a length of cable having a configurable cage, at least part of which is radio-opaque to allow detection of the configurable cage using X-ray guidance, connected to a distal end thereof, the length of cable and configurable cage being slidably moveable with respect to the flexible delivery tube to allow the configurable cage to be moved to and from a position substantially internal the flexible delivery tube and a position substantially external the flexible delivery tube, the configurable cage adopting a collapsed configuration when housed within the flexible delivery tube and an expanded configuration when located exterior the flexible delivery tube, the configurable cage being collapsible on withdrawal internal the flexible delivery tube from a position external the flexible delivery tube.
  • the gastronomy tube placement device By having such a gastronomy tube placement device, it is possible to insert a gastronomy tube in a patient without the use of an endoscope. Therefore, the, placement of the gastronomy tube will no longer require expensive equipment that is not readily available to the medical practitioner in order to be carried out in a quick and efficient manner.
  • the gastronomy tube may be inserted into a patient simply by using X-ray or fluoroscopic guidance if appropriate and it is possible to achieve the benefits of the pull technique without the need for an endoscope.
  • the cage is detectable under X- ray or may be detectable under fluoroscopic guidance and therefore, the medical practitioner is able to determine the location of the cage in the patient's stomach in a simple manner before inserting a cannula and a guide wire through the patient's abdominal wall into their stomach.
  • the cage will enable the medical practitioner to snare the guide wire with the minimum degree of difficulty.
  • the device is of relatively simple construction and will be relatively inexpensive to manufacture particularly when compared to the costs associated with an endoscope.
  • a gastronomy tube placement device in which the configurable cage is constructed from a resiliently deformable material.
  • the cage will automatically attempt to assume its expanded configuration once it exits the flexible delivery tube thereby automatically providing a target for snaring a wire inside a patient's stomach. This is a simple way of providing a large expanded cage target for the medical practitioner.
  • a gastronomy tube placement device in which the configurable cage is constructed from a memory- shaped material that assumes a predetermined expanded configuration external the flexible delivery tube on expulsion from the delivery tube.
  • the configurable cage will assume a predetermined configuration or shape that is known to the medical practitioner.
  • certain shapes of configurable cage may be chosen that are relatively simple to ensure that a guide wire can be snared therein with the minimum of difficulty.
  • a gastronomy tube placement device in which the configurable cage is constructed from a thermally reactive material that assumes a predetermined expanded configuration external the flexible delivery tube on heating above a predetermined transition temperature.
  • the configurable cage may be pushed out of the flexible delivery tube and thereafter the tube may be caused to expand by contacting the cage with the interior wall of the patient's stomach.
  • the thermally reactive, or in other words thermally responsive, material the cage will form a more rigid expanded structure that will be less prone to collapse due to external interference.
  • the thermally reactive material will have a transition temperature of between 20 0 C and 37 0 C. It is further envisaged that the thermally reactive material will have a transition temperature of approximately 35°C and preferably, the transition temperature will be in or around the human body temperature of 37 0 C.
  • a gastronomy tube placement device in which the configurable cage, in an expanded configuration, is at least 6cm in length and at least 3 cm in width. It is further envisaged that the configurable cage, in an expanded configuration, may be at least 8cm in length and at least 4cm in width. It is further still envisaged that the configurable cage, in an expanded configuration, may be at least 10cm in length and at least 5cm in width. Preferably, the configurable cage, in an expanded configuration, is at least 9cm long and at least 6cm wide. In this way, the cage will provide a sufficiently large target to allow the individual carrying out the procedure to successfully catch a wire passed through into the patient's stomach and remove the wire with relative ease. This will also have the effect that there is a stronger chance of successfully snaring the wire on the first attempt thereby speeding up the process significantly.
  • a gastronomy tube placement device in which the configurable cage is constructed using a radio-opaque material to allow detection of the configurable cage under X-Ray or fluoroscopic guidance.
  • the cage will be easily located with the aid of X-ray or fluoroscopic guidance.
  • the cage will be located in a simple and inexpensive manner using equipment that is widely accessible.
  • a gastronomy tube placement device in which the configurable cage is constructed from nitinol.
  • Nitinol is seen as a particularly suitable material to use in the present invention.
  • nitinol will provide relatively little friction when being slid in the flexible delivery tube.
  • nitinol is radio-opaque and will show up on X-Rays.
  • the nitinol is thermally responsive and the transition temperature of the nitinol may be set relatively accurately so that the nitinol will operate reliably.
  • the nitinol is bio ⁇ compatible and will not cause an adverse reaction in the patient.
  • a gastronomy tube placement device in which the configurable cage is constructed from a combination of nitinol and a second material with a radio-opacity greater than nitinol.
  • the nitinol wire may be provided with a lesser cross section as the second material with a greater radio-opacity will cause the configurable cage to be more easily identifiable under X-ray. This can cause considerable savings in the manufacture of the device and furthermore will enable the medical practitioner to more easily identify the target for snaring the guide wire.
  • a gastronomy tube placement device in which the configurable cage is constructed from an alloy of nitinol and the second material with a radio-opacity greater than nitinol.
  • a gastronomy tube placement device in which the configurable cage is constructed from a wire having a core and an outer covering portion surrounding the core, one of the nitinol and the second material with a radio-opacity greater than nitinol forming the core and the other of the nitinol and the second material with the radio-opacity greater than nitinol forming the outer covering portion.
  • a gastronomy tube placement device in which the second material with a radio-opacity greater than nitinol is platinum.
  • platinum is seen as a very useful material to use in conjunction with the nitinol. Although platinum may degrade the thermal responsiveness of the nitinol configurable cage somewhat, the platinum is highly visible under X-ray or fluoroscopic guidance and will enable the configurable cage to be identified with relative ease.
  • the configurable cage comprises between 80% and 98% nitinol, and between 20% and 2% platinum.
  • a gastronomy tube placement device in which the configurable cage and the cable are formed integrally as a single unit. This will allow the device to be constructed with a single length of wiring or a number of wires wound together in a simple and inexpensive manner.
  • the configurable cage and the cable may be separate components connected together at a crimp joint. This will allow for different materials to be used for the configurable cage and the cable and therefore a more heavy duty or less expensive material may be used for the cable as desired.
  • a gastronomy tube placement device in which the flexible tube further comprises one of a nasogastric and an orogastric tube.
  • a gastronomy tube placement device in which there is provided an actuating mechanism connected to the proximal end of the cable to facilitate manipulation of the snare within the flexible delivery tube and deployment and retrieval of the configurable cage relative the flexible delivery tube.
  • This actuating mechanism could comprise a trigger mechanism to manipulate the cable in the flexible tubing.
  • the actuating mechanism further comprises a substantially rigid pusher rod. This is seen as a simple and inexpensive device to use in order to manipulate the cable and hence the configurable cage.
  • a gastronomy tube placement device in which the flexible delivery tube is provided with at least one distance marking about its outer surface indicating a predetermined distance from the distal end of the flexible delivery tube to the distance marking.
  • the medical practitioner can keep track on the distance into the patient that the distal end of the gastronomy tube placement device has travelled and can estimate from the distance marking the approximate location of the distal end of the flexible delivery tube. Therefore, it will be possible for the medical practitioner to accurately determine when the distal end of the device is in the patients stomach taking into account the size of the patient and when it is time to deploy the configurable cage.
  • a gastronomy tube placement device in which the flexible delivery tube further comprises a connector mounted on the proximal end of the flexible delivery tube, the connector having an aperture for through passage of the snare and a side port for connection to a gas supply.
  • the gastronomy tube placement device comprising a flexible delivery tube substantially housing a snare, the snare being slidably mounted in the flexible delivery tube and the snare comprising a cable having a configurable cage, at least part of which is radio-opaque to allow detection of the configurable cage using X-ray or fluoroscopic guidance, mounted on the distal end thereof;
  • the gastronomy tube may be inserted into a patient undergoing difficulties feeding themselves in a simple and efficient manner.
  • the method allows for the application of the pull technique and at the same time obviates the need for the use of an endoscope. Therefore, the procedure may be carried out in a radiology department without the need for sutures and lengthy medical procedures.
  • the method is quick and efficient and requires only basic equipment that can be readily available in hospital radiology departments.
  • a method of placement of a gastronomy tube in which the method further comprises the intermediate step of pumping gas into the patients stomach along the flexible delivery tube subsequent to placement of the distal end of the delivery tube in the patients stomach and prior to deployment of the configurable cage.
  • gas preferably air
  • the patient's stomach will become distended and will allow the configurable cage to expand relatively uninhibited by its surroundings. This will help to ensure that the configurable cage is deployed correctly.
  • a method of placement of a gastronomy tube in which the method further comprises the intermediate step of removing the cannula from the patient's abdomen prior to pulling the gastronomy tube through the abdominal wall. By removing the cannula, it will not cause an obstruction to the gastronomy tube when the gastronomy tube is being drawn through the stomach and abdominal wall.
  • a method of placement of a gastronomy tube in which the method further comprises the intermediate step of taking a further X-ray of the patients abdominal region including their stomach containing the configurable cage subsequent to inserting the guide wire through the cannula and prior to retracting the configurable cage back into the flexible delivery tube to ensure that the guide wire has passed through the collapsible cage.
  • a method of placement of a gastronomy tube in which the configurable cage is constructed from a thermally reactive material that assumes a predetermined expanded configuration external the flexible delivery tube on heating above a predetermined transition temperature and in which the method further comprises the intermediate step of placing the configurable cage in contact against the interior stomach wall of the patient subsequent to expulsion of the configurable cage from the flexible delivery tube to heat the configurable cage to the predetermined transition temperature.
  • a method of placement of a gastronomy tube in which the method further comprises the initial step of running a lubricant through the flexible delivery tube prior to insertion into the patient.
  • the snare will be less likely to snag in the flexible tubing and will be deployed in a relatively simple manner.
  • Fig. 1 is a diagrammatic side view of a gastronomy tube placement device according to the invention
  • Fig. 2 is an enlarged side view of part of the gastronomy tube placement device with the snare cage in a stored collapsed configuration
  • Fig. 3 is an enlarged side view of part of the gastronomy tube placement device with the snare cage in an open expanded configuration
  • Fig. 4 is an enlarged side view of part of the gastronomy tube placement device with a connector attached thereto;
  • Fig. 5 is an enlarged side view of part of the gastronomy tube placement device of Fig. 4 including rod;
  • Fig. 6 is a diagrammatic side view of a snare in accordance with the invention shown without the delivery tube;
  • Fig. 7 is a sectional view of a patient with the gastronomy tube placement device fed into their stomach and with the cage deployed;
  • Fig. 8 is a sectional view of a patient with the gastronomy tube placement device inserted and the snare gripping a length of wire;
  • Fig. 9 is a sectional view of a patient having had the wire led out through their mouth and now connected to a feeding tube;
  • Fig. 10 is a sectional view of a patient having had the gastronomy tube drawn through the patient's mouth, oesophagus and extracted through the stomach and abdominal walls;
  • Fig. 11 is an enlarged side view of part of an alternative embodiment of gastronomy tube placement device with the snare cage in an open expanded configuration
  • a gastronomy tube placement device comprising a flexible delivery tube 2 and a snare 3 housed substantially within the delivery tube 2.
  • the snare further comprises a length of cable 4 having a configurable cage 5 connected to a distal end 6 thereof.
  • the configurable cage 5 is actuated from a closed stored configuration, as shown in Fig. 2, to an open expanded configuration, as illustrated in Fig. 3, by pushing the length of cable 4 through the flexible delivery tube 2 from the cable's proximal end 7, thus causing the cage to exit the tube and expand into its open expanded configuration.
  • the cage 5 may be returned to the closed stored configuration by simply pulling the cable 4 back through the flexible delivery tube in the opposite direction and causing the cage 5 to retreat back into the tube 2.
  • a gastronomy tube placement device having a connector 9 attached to one end of the flexible delivery tube.
  • the connector 9 further comprises a side port 10 for connection to an air supply (not shown).
  • a gastronomy tube placement device having a connector 9 with side port 10 connected to an end of the flexible delivery tube.
  • a rod 11 is connected to the proximal end 7 of the cable by a suitable weld joint.
  • the connector 9 forms a tight seal with the rod 11.
  • the snare 3 comprises a cable 4 with a configurable cage 5 connected to the distal end 6 thereof.
  • a pair of joints 13, 14 are located, one at either end of the configurable cage 5.
  • the cage 5 is connected to the cable 4 at the joint 13.
  • the cable comprises four separate wires wound tightly together and joined by joint 13. The wires then separate out to form cage bars 15(a) to 15(d) respectively.
  • Each of the cage bars 15(a) to 15(d) is crimped at knee joints 16(a) to 16(d) respectively, which provides the resiliently deformable characteristic of the cage.
  • the four cage bars 15(a) to 15(d) are then joined together again in joint 14.
  • the joint 14 terminates in a rounded tip 17 to prevent inadvertent injury to the patient when the snare is deployed.
  • the cage and the cable are therefore formed integrally with each other.
  • the joints 13 and 14 can be either weld joints, crimp joints or other such type of joints to join the wires of the cage together and/or join the wires to the cable 4.
  • the type of joint used will largely depend on the materials used for the wires of the cage.
  • a gastronomy tube placement device 1 has been inserted into the patient's stomach 18 and air has been pumped through the flexible delivery tube 2 until the stomach is distended.
  • the snare is progressed through the flexible delivery tube 2 by pushing the rod 11 into the flexible delivery tube 2.
  • This causes the cable 4 to progress through the flexible delivery tube 2 and in turn causes the cage 5 to be expelled from the end of the delivery tube 2.
  • the resiliently deformable cage 5 is expelled, it expands into its open configuration.
  • An x-ray of the patient's abdomen is then taken to ascertain the location of the expanded cage.
  • At least part of the configurable cage is radio-opaque. It will be understood that in some instances, these parts of the snare that are radio-opaque must be sufficiently radio-opaque so that they are visible under low dose fluoroscopic screening despite the scattered radiation and quantum mottle associated with the abdomen, if fluoroscopic screening is to be used.
  • a cannula 20 is then inserted through the patient's abdomen into their stomach in the vicinity of the cage 5.
  • a guide wire 22 is inserted through the cannula and fed into the stomach. The guide wire then passes through the cage 5.
  • the rod 11 is slowly pulled back out of the flexible delivery tube which in turn pulls the cable 4 and hence the cage 5 back inside the delivery tube. As the cage 5 moves back inside the delivery tube, it once again collapses; trapping the guide wire 22 between two or more cage bars 15(a) to 15(d).
  • the gastronomy tube placement device 1 and guide wire 22 are pulled through the patient's oesophagus 24 and out through the patient's mouth. Care must be taken that the guide wire is of sufficient length so that it does not pull through totally and that there is part of guide wire protruding from the cannula 20.
  • the guide wire is then separated from the cage and the end of the guide wire that was connected to the cage 5 is connected to a gastronomy tube 26 by a suitable knot.
  • the cannula 20 is removed from the patient's abdomen and the gastronomy tube 26 is slowly pulled through the patient's oesophagus 24 into the stomach 18 by pulling on the other end of the guide wire. Further pulling of the guide wire 22 causes the gastronomy tube to be pulled partially through the stomach wall and anterior abdominal wall. A circular flange 28 on the gastronomy tube prevents the tube being pulled through in its entirety.
  • the gastronomy tube may then be secured in place by fixing a skin disk (not shown) around the tube and onto the outer abdomen and the gastronomy tube is then cut to the desired length. Additional connectors (not shown) may then be added to the gastronomy tube to facilitate feeding.
  • the snare cage 5 is formed using thermally responsive Nitinol (Registered Trade Mark (RTM)).
  • RTM Thermally responsive Nitinol
  • the thermally responsive Nitinol (RTM) cage 5 is inserted into the patients stomach in the manner previously described. Instead of expanding through resilience on deployment from the flexible tube, the Nitinol (RTM) cage 5 expands once it is heated to a predetermined temperature.
  • the expanding temperature of the Nitinol (RTM) may be set during the manufacturing process and for the purposes of the medical device this temperature will typically be in the range of between 20 0 C and 30 0 C. Alternatively, the expanding temperature could be in the range between 2O 0 C and 37°C.
  • the wires are also pre-bent in the manufacturing process. Once the Nitinol (RTM) is heated up to this temperature, the Nitinol (RTM) will reform into the open cage configuration. It is envisaged that in order to heat the Nitinol (RTM) cage up to a sufficient temperature, the cage 5 may be deployed from the tube 2 and then placed up against the internal wall of the patient's stomach where it will be gradually heated to the desired temperature. The cage 5 will then expand and be ready to snare a wire (not shown) inserted into the patient's stomach.
  • the thermally expanding cage shown comprises four wires, 41 , 42, 43, and 44, each of which is crimped at knee joints to form a substantially rectangular cage loop with an opposing wire. All of the wires combined will form a substantially box-like configuration of cage. It will be understood however that more or less than four wires could be provided.
  • the wires are joined at each end by stainless steel joints 13, 14.
  • the pusher cable 46 is a stainless steel flexible cable. It is envisaged that this cable may be wound stainless steel.
  • the cage 5 expands outwards to a length of between 10 and 12 cm and a width of between 8 and 10 cm.
  • the cage and the cable were formed integrally with each other. This need not be the case and the two may be formed separately and connected at the weld joint 13.
  • the cage in the embodiment shown consists of four separate cage bars 15(a) to 15(d) constructed from four separate wires. It will also be understood that the number of cage bars need only be two, three, four or more in order to trap the guide wire but four has been found to be quite efficient for the purposes of catching the wire. It is further envisaged that the cage bars could be formed by a single length of cable led back on itself a number of times to form the cage. In the embodiments shown, a rod has been used to manipulate the snare in the flexible delivery tube.
  • any other device for paying out and reeling in the cable could be used and this device could typically be in the form of a handle and trigger arrangement connected to the end of the tube.
  • a detachable mechanical hand powered driver could be used to manipulate the cable in the flexible delivery tube.
  • the snare may be constructed using stainless steel wire, a strengthened plastic material, nitinol or other equivalent material.
  • a 16F gauge or 18F gauge tube is used for the delivery tube, as these are narrow enough to be placed relatively comfortably for the patient, without requiring sedation of the patient. Secondly, there is a lesser tendency for the tube to become blocked when being inserted into the patient. Smaller gauge tubes could also be used in the procedure if desired.
  • weld joints crimp joints, welds and the like have been used interchangeably. It would be understood however by the skilled addressee that certain materials, such as nitinol, may not be able to be "welded” in their thermally preconditioned states and would in fact be connected to other components, i.e. the cable 4, by a crimp joint or other suitable connection. It would however be possible to weld the stainless steel if that was the material used for the configurable cage.
  • connection will in fact be dictated to a large extent by the materials used for the configurable cage and when nitinol is used for the configurable cage, it will be connected to the cable by a crimp joint or other suitable joint other than a weld joint.

Abstract

The invention relates to a gastronomy tube placement device (1) comprising a flexible delivery tube (2) housing a snare (3). The snare (3) further comprises a cable (4) having a configurable cage (5) mounted on a distal end thereof. At least part of the configurable cage (5) is radio-opaque to allow detection of the configurable cage using X-ray guidance. The snare (3) is slidably moveable in the flexible delivery tube (2) so that the configurable cage may be moved to and from a position internal the flexible delivery tube and a position external the flexible delivery tube. The configurable cage (5) assumes an expanded configuration outside the flexible delivery tube (2) and is collapsible on withdrawal inside the flexible delivery tube. The gastronomy tube placement device can be used in the placement of a gastronomy tube using fluoroscopic guidance without the assistance of an endoscope.

Description

"A Gastronomy Tube Placement Device"
Introduction
This invention relates to a gastronomy tube placement device and a method of placement of a gastronomy tube.
One procedure that is regularly carried out in hospitals is the placement of a gastronomy tube. A gastronomy tube is typically inserted into patients that are undergoing severe difficulty swallowing such as those patients suffering from cancer of the oesophagus or in patients unable to feed themselves such as in the case of stroke victims or Alzheimer sufferers. The gastronomy tube provides a direct feeding passageway to the patient through the stomach wall and is a highly effective way of feeding a patient unable to fulfil their own nutritional needs orally.
Over the years, various different techniques have been devised to place gastronomy tubes in patients. Increasingly however, these gastronomy tubes are being placed radiologically. One commonly known technique used for the radiological placement of gastronomy tubes is the so-called "push" technique. The "push" technique comprises inserting a nasogastric or orogastric air tube through the patient's nose or mouth respectively and thereafter guiding the air tube down the patient's oesophagus into their stomach. Air is then pumped through the air tube until the stomach is distended. Once the stomach has been fully distended, two or four suture devices are punctured into the stomach and sutured to the skin of the abdomen to hold the stomach wall to the anterior abdominal wall. The stomach is then punctured with a cannula and a wire is inserted into the stomach. The tract of the wire is gradually dilated using plastic tubes until a large gastronomy tube is placed over the wire, through the anterior abdominal wall and secured in place.
There are, however, several problems associated with this so-called "push" technique and the apparatus used in the insertion of the gastronomy tube. First of all, this "push" technique requires the use of sutures which are often time consuming for the medical practitioner to insert and also increase the risk to the patient of localised inflammation or infection. Secondly, the use of plastic tubes as sequential dilators is quite time consuming and the physicians time is taken up in a relatively lengthy procedure that could be better spent attending to other patients needs.
Another technique that is used for the placement of gastronomy tubes is the so-called "pull" technique. This technique involves the use of an endoscope. The "pull" technique entails sedating the patient and feeding an endoscope through the patient's mouth until the tip of the endoscope enters the stomach. Once in place, air is fed through the endoscope until the patient's stomach is distended and a light source located at the tip of the endoscope is turned on and shone upon the abdomen of the patient. The physician locates the tip by viewing the light source shining on the patient's abdominal wall and thereafter, the physician inserts a needle through the patient's abdomen into the stomach in the vicinity of the endoscope's tip. A length of wire is then fed through the needle and grasped by a gripping member of the endoscope. The endoscope is then withdrawn from the patients stomach which in turn pulls the wire through the patient's stomach up through the oesophagus and out through their mouth. Sufficient wire is used so that the wire is not pulled fully through the needle in the patient's abdomen. The end of the wire caught in the gripping member is then released from the gripping member and that free end of the wire is tied to a gastronomy tube using a suitable knot. The gastronomy tube, now attached to the wire, is pulled through the patient's mouth, down their oesophagus and into their stomach by pulling on the other end of the guide wire protruding from the needle in the patient's abdomen. The gastronomy tube is then pulled partially through the patient's stomach wall and secured in place.
There are several advantages of this so-called "pull" technique and the equipment used in the technique, over the techniques and equipment previously described. First of all, the "pull" technique obviates the need to suture the patient's stomach wall to their anterior abdominal wall. As sutures do not have to be used, this decreases the possibility of inflammation and infection around the gastronomy tube and further obviates the need for a medical practitioner to spend time applying the sutures. Therefore, this "pull" method is seen as a quick and efficient technique for inserting a gastronomy tube that reduces the chances of infection and inflammation in the patient. There are, however, several drawbacks associated with the "pull" technique of placing a gastronomy tube described above. The most significant drawback of the "pull" technique described above is the necessity to provide an endoscope to carry out the procedure. This is undesirable for a number of reasons and the most prohibitive factor being the expense of an endoscope. Generally speaking, endoscopes cost several thousand Euros to purchase and, with strict hospital budgets, are not generally provided in radiology departments. Therefore, this "pull" technique is not usually available to the physician carrying out the procedure. Another drawback of this technique is that due to the relatively bulky size of the endoscope, the patient must be sedated during the procedure which always has risks associated with it.
It is an object therefore of the present invention to provide a device and a technique for inserting a gastronomy tube that overcomes at least some of the above- mentioned difficulties.
Statements of Invention
According to the invention there is provided a gastronomy tube placement device comprising a flexible delivery tube and a snare housed substantially within the flexible delivery tube, the snare further comprising a length of cable having a configurable cage, at least part of which is radio-opaque to allow detection of the configurable cage using X-ray guidance, connected to a distal end thereof, the length of cable and configurable cage being slidably moveable with respect to the flexible delivery tube to allow the configurable cage to be moved to and from a position substantially internal the flexible delivery tube and a position substantially external the flexible delivery tube, the configurable cage adopting a collapsed configuration when housed within the flexible delivery tube and an expanded configuration when located exterior the flexible delivery tube, the configurable cage being collapsible on withdrawal internal the flexible delivery tube from a position external the flexible delivery tube.
By having such a gastronomy tube placement device, it is possible to insert a gastronomy tube in a patient without the use of an endoscope. Therefore, the, placement of the gastronomy tube will no longer require expensive equipment that is not readily available to the medical practitioner in order to be carried out in a quick and efficient manner. By using such a gastronomy tube placement device, the gastronomy tube may be inserted into a patient simply by using X-ray or fluoroscopic guidance if appropriate and it is possible to achieve the benefits of the pull technique without the need for an endoscope. The cage is detectable under X- ray or may be detectable under fluoroscopic guidance and therefore, the medical practitioner is able to determine the location of the cage in the patient's stomach in a simple manner before inserting a cannula and a guide wire through the patient's abdominal wall into their stomach. The cage will enable the medical practitioner to snare the guide wire with the minimum degree of difficulty. Finally, the device is of relatively simple construction and will be relatively inexpensive to manufacture particularly when compared to the costs associated with an endoscope.
In one embodiment of the invention there is provided a gastronomy tube placement device in which the configurable cage is constructed from a resiliently deformable material. By having a configurable cage formed from a resiliently deformable material, the cage will automatically attempt to assume its expanded configuration once it exits the flexible delivery tube thereby automatically providing a target for snaring a wire inside a patient's stomach. This is a simple way of providing a large expanded cage target for the medical practitioner.
In another embodiment of the invention there is provided a gastronomy tube placement device in which the configurable cage is constructed from a memory- shaped material that assumes a predetermined expanded configuration external the flexible delivery tube on expulsion from the delivery tube. In this way, the configurable cage will assume a predetermined configuration or shape that is known to the medical practitioner. In this way, certain shapes of configurable cage may be chosen that are relatively simple to ensure that a guide wire can be snared therein with the minimum of difficulty.
In a further embodiment of the invention there is provided a gastronomy tube placement device in which the configurable cage is constructed from a thermally reactive material that assumes a predetermined expanded configuration external the flexible delivery tube on heating above a predetermined transition temperature. In this way, the configurable cage may be pushed out of the flexible delivery tube and thereafter the tube may be caused to expand by contacting the cage with the interior wall of the patient's stomach. By using the thermally reactive, or in other words thermally responsive, material, the cage will form a more rigid expanded structure that will be less prone to collapse due to external interference. It is envisaged that the thermally reactive material will have a transition temperature of between 200C and 370C. It is further envisaged that the thermally reactive material will have a transition temperature of approximately 35°C and preferably, the transition temperature will be in or around the human body temperature of 370C.
In one embodiment of the invention there is provided a gastronomy tube placement device in which the configurable cage, in an expanded configuration, is at least 6cm in length and at least 3 cm in width. It is further envisaged that the configurable cage, in an expanded configuration, may be at least 8cm in length and at least 4cm in width. It is further still envisaged that the configurable cage, in an expanded configuration, may be at least 10cm in length and at least 5cm in width. Preferably, the configurable cage, in an expanded configuration, is at least 9cm long and at least 6cm wide. In this way, the cage will provide a sufficiently large target to allow the individual carrying out the procedure to successfully catch a wire passed through into the patient's stomach and remove the wire with relative ease. This will also have the effect that there is a stronger chance of successfully snaring the wire on the first attempt thereby speeding up the process significantly.
In one embodiment of the invention there is provided a gastronomy tube placement device in which the configurable cage is constructed using a radio-opaque material to allow detection of the configurable cage under X-Ray or fluoroscopic guidance. This is seen as particularly advantageous as by having a radio-opaque material, the cage will be easily located with the aid of X-ray or fluoroscopic guidance. The cage will be located in a simple and inexpensive manner using equipment that is widely accessible.
In another embodiment of the invention there is provided a gastronomy tube placement device in which the configurable cage is constructed from nitinol. Nitinol is seen as a particularly suitable material to use in the present invention. First of all, nitinol will provide relatively little friction when being slid in the flexible delivery tube. Secondly, nitinol is radio-opaque and will show up on X-Rays. Thirdly, the nitinol is thermally responsive and the transition temperature of the nitinol may be set relatively accurately so that the nitinol will operate reliably. Finally, the nitinol is bio¬ compatible and will not cause an adverse reaction in the patient.
In a further embodiment of the invention there is provided a gastronomy tube placement device in which the configurable cage is constructed from a combination of nitinol and a second material with a radio-opacity greater than nitinol. In this way, the nitinol wire may be provided with a lesser cross section as the second material with a greater radio-opacity will cause the configurable cage to be more easily identifiable under X-ray. This can cause considerable savings in the manufacture of the device and furthermore will enable the medical practitioner to more easily identify the target for snaring the guide wire.
In one embodiment of the invention there is provided a gastronomy tube placement device in which the configurable cage is constructed from an alloy of nitinol and the second material with a radio-opacity greater than nitinol. Alternatively, there is provided a gastronomy tube placement device in which the configurable cage is constructed from a wire having a core and an outer covering portion surrounding the core, one of the nitinol and the second material with a radio-opacity greater than nitinol forming the core and the other of the nitinol and the second material with the radio-opacity greater than nitinol forming the outer covering portion.
In a further embodiment of the invention there is provided a gastronomy tube placement device in which the second material with a radio-opacity greater than nitinol is platinum. Platinum is seen as a very useful material to use in conjunction with the nitinol. Although platinum may degrade the thermal responsiveness of the nitinol configurable cage somewhat, the platinum is highly visible under X-ray or fluoroscopic guidance and will enable the configurable cage to be identified with relative ease. Preferably, there is provided a gastronomy tube placement device in which the configurable cage comprises between 80% and 98% nitinol, and between 20% and 2% platinum. In another embodiment of the invention there is provided a gastronomy tube placement device in which the configurable cage and the cable are formed integrally as a single unit. This will allow the device to be constructed with a single length of wiring or a number of wires wound together in a simple and inexpensive manner. Alternatively, the configurable cage and the cable may be separate components connected together at a crimp joint. This will allow for different materials to be used for the configurable cage and the cable and therefore a more heavy duty or less expensive material may be used for the cable as desired.
In one embodiment of the invention there is provided a gastronomy tube placement device in which the flexible tube further comprises one of a nasogastric and an orogastric tube.
In another embodiment of the invention there is provided a gastronomy tube placement device in which there is provided an actuating mechanism connected to the proximal end of the cable to facilitate manipulation of the snare within the flexible delivery tube and deployment and retrieval of the configurable cage relative the flexible delivery tube. This actuating mechanism could comprise a trigger mechanism to manipulate the cable in the flexible tubing. In a further embodiment of the invention, the actuating mechanism further comprises a substantially rigid pusher rod. This is seen as a simple and inexpensive device to use in order to manipulate the cable and hence the configurable cage.
In one embodiment of the invention there is provided a gastronomy tube placement device in which the flexible delivery tube is provided with at least one distance marking about its outer surface indicating a predetermined distance from the distal end of the flexible delivery tube to the distance marking. By having a distance marking, the medical practitioner can keep track on the distance into the patient that the distal end of the gastronomy tube placement device has travelled and can estimate from the distance marking the approximate location of the distal end of the flexible delivery tube. Therefore, it will be possible for the medical practitioner to accurately determine when the distal end of the device is in the patients stomach taking into account the size of the patient and when it is time to deploy the configurable cage. Preferably, there will be provided a plurality of distance markings spaced apart along the outside of the flexible delivery tube.
In one embodiment of the invention there is provided a gastronomy tube placement device in which the flexible delivery tube further comprises a connector mounted on the proximal end of the flexible delivery tube, the connector having an aperture for through passage of the snare and a side port for connection to a gas supply.
In another embodiment of the invention there is provided a method of placement of a gastronomy tube comprising the steps of:
delivering a distal end of a gastronomy tube placement device through a patients mouth or nose, along their oesophagus and into the patients stomach, the gastronomy tube placement device comprising a flexible delivery tube substantially housing a snare, the snare being slidably mounted in the flexible delivery tube and the snare comprising a cable having a configurable cage, at least part of which is radio-opaque to allow detection of the configurable cage using X-ray or fluoroscopic guidance, mounted on the distal end thereof;
once the distal end of the gastronomy tube placement device is in position in the patients stomach, sliding the snare along the flexible delivery tube until the configurable cage exits the distal end of the flexible delivery tube and assumes an expanded configuration;
taking an X-ray of the patient's abdomen including their stomach containing the deployed expanded configurable cage to determine the location of the configurable cage in the patient's stomach;
inserting a cannula through the patient's abdominal wall in the vicinity of the configurable cage;
partially feeding a guide wire through the cannula into and through the configurable cage; retracting the configurable cage back into the flexible delivery tube thereby collapsing the configurable cage and trapping the guide wire in the configurable cage;
withdrawing the distal end of the gastronomy tube placement device from the patient's stomach, back through their oesophagus and out through their nose or mouth;
releasing the end of the guide wire from the configurable cage and thereafter tying a gastronomy tube to that end of the guide wire; and
pulling the other end of the guide wire protruding from the patients abdomen so that end of the guide wire with the gastronomy tube attached thereto is drawn through the patients mouth or nose, along their oesophagus and into their stomach, and gradually pulling part of the gastronomy tube through the abdominal wall before securing the gastronomy tube in place.
By having such a method, the gastronomy tube may be inserted into a patient undergoing difficulties feeding themselves in a simple and efficient manner. Most beneficially, the method allows for the application of the pull technique and at the same time obviates the need for the use of an endoscope. Therefore, the procedure may be carried out in a radiology department without the need for sutures and lengthy medical procedures. The method is quick and efficient and requires only basic equipment that can be readily available in hospital radiology departments.
In a further embodiment of the invention there is provided a method of placement of a gastronomy tube in which the method further comprises the intermediate step of pumping gas into the patients stomach along the flexible delivery tube subsequent to placement of the distal end of the delivery tube in the patients stomach and prior to deployment of the configurable cage. By pumping gas, preferably air, into the patient's stomach, the patient's stomach will become distended and will allow the configurable cage to expand relatively uninhibited by its surroundings. This will help to ensure that the configurable cage is deployed correctly.
In one embodiment of the invention there is provided a method of placement of a gastronomy tube in which the method further comprises the intermediate step of removing the cannula from the patient's abdomen prior to pulling the gastronomy tube through the abdominal wall. By removing the cannula, it will not cause an obstruction to the gastronomy tube when the gastronomy tube is being drawn through the stomach and abdominal wall.
In another embodiment of the invention there is provided a method of placement of a gastronomy tube in which the method further comprises the intermediate step of taking a further X-ray of the patients abdominal region including their stomach containing the configurable cage subsequent to inserting the guide wire through the cannula and prior to retracting the configurable cage back into the flexible delivery tube to ensure that the guide wire has passed through the collapsible cage.
In a further embodiment of the invention there is provided a method of placement of a gastronomy tube in which the configurable cage is constructed from a thermally reactive material that assumes a predetermined expanded configuration external the flexible delivery tube on heating above a predetermined transition temperature and in which the method further comprises the intermediate step of placing the configurable cage in contact against the interior stomach wall of the patient subsequent to expulsion of the configurable cage from the flexible delivery tube to heat the configurable cage to the predetermined transition temperature. This is seen as a particularly simple way in which the cage may be caused to reach its transition temperature and expand outwards as desired.
In one embodiment of the invention there is provided a method of placement of a gastronomy tube in which the method further comprises the initial step of running a lubricant through the flexible delivery tube prior to insertion into the patient. In this way, the snare will be less likely to snag in the flexible tubing and will be deployed in a relatively simple manner.
Detailed Description of the Invention The invention will now be more clearly understood from the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which:-
Fig. 1 is a diagrammatic side view of a gastronomy tube placement device according to the invention,
Fig. 2 is an enlarged side view of part of the gastronomy tube placement device with the snare cage in a stored collapsed configuration;
Fig. 3 is an enlarged side view of part of the gastronomy tube placement device with the snare cage in an open expanded configuration;
Fig. 4 is an enlarged side view of part of the gastronomy tube placement device with a connector attached thereto;
Fig. 5 is an enlarged side view of part of the gastronomy tube placement device of Fig. 4 including rod;
Fig. 6 is a diagrammatic side view of a snare in accordance with the invention shown without the delivery tube;
Fig. 7 is a sectional view of a patient with the gastronomy tube placement device fed into their stomach and with the cage deployed;
Fig. 8 is a sectional view of a patient with the gastronomy tube placement device inserted and the snare gripping a length of wire;
Fig. 9 is a sectional view of a patient having had the wire led out through their mouth and now connected to a feeding tube;
Fig. 10 is a sectional view of a patient having had the gastronomy tube drawn through the patient's mouth, oesophagus and extracted through the stomach and abdominal walls; and
Fig. 11 is an enlarged side view of part of an alternative embodiment of gastronomy tube placement device with the snare cage in an open expanded configuration
Referring now to the drawings and initially to Figs. 1 to 3 thereof, there is shown a gastronomy tube placement device, indicated generally by the reference numeral 1 , comprising a flexible delivery tube 2 and a snare 3 housed substantially within the delivery tube 2. The snare further comprises a length of cable 4 having a configurable cage 5 connected to a distal end 6 thereof. The configurable cage 5 is actuated from a closed stored configuration, as shown in Fig. 2, to an open expanded configuration, as illustrated in Fig. 3, by pushing the length of cable 4 through the flexible delivery tube 2 from the cable's proximal end 7, thus causing the cage to exit the tube and expand into its open expanded configuration. The cage 5 may be returned to the closed stored configuration by simply pulling the cable 4 back through the flexible delivery tube in the opposite direction and causing the cage 5 to retreat back into the tube 2.
It will be understood that many of the drawings and in particular Figure 1 have not been drawn to scale for reasons of clarity. In reality, the gastronomy tube placement device shown in Figure 1 is in fact between 1 metre and 1.5 metres long (approximately 1.2 metres long) and between 0.4 cm and 0.8 cm (approximately 0.6 cm) in diameter (depending on the gauge of flexible delivery tube used) but for reasons of clarity, the parts have not been shown to scale.
Referring now to Fig. 4 of the drawings, where like parts have been given the same reference numerals as before, there is shown a gastronomy tube placement device having a connector 9 attached to one end of the flexible delivery tube. The connector 9 further comprises a side port 10 for connection to an air supply (not shown). Referring now to Fig. 5 of the drawings, where like parts have been given the same reference numerals, there is shown a gastronomy tube placement device having a connector 9 with side port 10 connected to an end of the flexible delivery tube. A rod 11 is connected to the proximal end 7 of the cable by a suitable weld joint. The connector 9 forms a tight seal with the rod 11. In use, once the flexible delivery tube is in position in the patient's stomach, air is pumped from the air supply through side port 10 and thereafter through flexible delivery tube 2, into the patient's stomach until the patient's stomach is fully distended. The cage is then manipulated by the physician by pushing or pulling the rod 11 , as required.
Referring now to Fig. 6 of the drawings, there is shown a side view of the snare 3 in accordance with the invention. The snare 3 comprises a cable 4 with a configurable cage 5 connected to the distal end 6 thereof. A pair of joints 13, 14 are located, one at either end of the configurable cage 5. The cage 5 is connected to the cable 4 at the joint 13. In the embodiment shown, the cable comprises four separate wires wound tightly together and joined by joint 13. The wires then separate out to form cage bars 15(a) to 15(d) respectively. Each of the cage bars 15(a) to 15(d) is crimped at knee joints 16(a) to 16(d) respectively, which provides the resiliently deformable characteristic of the cage. The four cage bars 15(a) to 15(d) are then joined together again in joint 14. The joint 14 terminates in a rounded tip 17 to prevent inadvertent injury to the patient when the snare is deployed. The cage and the cable are therefore formed integrally with each other. The joints 13 and 14 can be either weld joints, crimp joints or other such type of joints to join the wires of the cage together and/or join the wires to the cable 4. The type of joint used will largely depend on the materials used for the wires of the cage.
Referring now to Figs. 7 to 10 of the drawings, there are shown sectional views of a patient in sequential stages of the procedure. In Fig. 7, a gastronomy tube placement device 1 has been inserted into the patient's stomach 18 and air has been pumped through the flexible delivery tube 2 until the stomach is distended. The snare is progressed through the flexible delivery tube 2 by pushing the rod 11 into the flexible delivery tube 2. This in turn causes the cable 4 to progress through the flexible delivery tube 2 and in turn causes the cage 5 to be expelled from the end of the delivery tube 2. As the resiliently deformable cage 5 is expelled, it expands into its open configuration.
An x-ray of the patient's abdomen is then taken to ascertain the location of the expanded cage. At least part of the configurable cage is radio-opaque. It will be understood that in some instances, these parts of the snare that are radio-opaque must be sufficiently radio-opaque so that they are visible under low dose fluoroscopic screening despite the scattered radiation and quantum mottle associated with the abdomen, if fluoroscopic screening is to be used. A cannula 20 is then inserted through the patient's abdomen into their stomach in the vicinity of the cage 5. A guide wire 22 is inserted through the cannula and fed into the stomach. The guide wire then passes through the cage 5. Once the guide wire has passed through the cage 5, the rod 11 is slowly pulled back out of the flexible delivery tube which in turn pulls the cable 4 and hence the cage 5 back inside the delivery tube. As the cage 5 moves back inside the delivery tube, it once again collapses; trapping the guide wire 22 between two or more cage bars 15(a) to 15(d).
Once the guide wire 22 has been trapped in the cage, the gastronomy tube placement device 1 and guide wire 22 are pulled through the patient's oesophagus 24 and out through the patient's mouth. Care must be taken that the guide wire is of sufficient length so that it does not pull through totally and that there is part of guide wire protruding from the cannula 20. The guide wire is then separated from the cage and the end of the guide wire that was connected to the cage 5 is connected to a gastronomy tube 26 by a suitable knot.
The cannula 20 is removed from the patient's abdomen and the gastronomy tube 26 is slowly pulled through the patient's oesophagus 24 into the stomach 18 by pulling on the other end of the guide wire. Further pulling of the guide wire 22 causes the gastronomy tube to be pulled partially through the stomach wall and anterior abdominal wall. A circular flange 28 on the gastronomy tube prevents the tube being pulled through in its entirety. The gastronomy tube may then be secured in place by fixing a skin disk (not shown) around the tube and onto the outer abdomen and the gastronomy tube is then cut to the desired length. Additional connectors (not shown) may then be added to the gastronomy tube to facilitate feeding.
Referring to Figure 11 of the drawings there is shown an enlarged side view of an alternative embodiment of gastronomy tube placement device according to the invention, where like parts have been given the same reference numeral as before. In the embodiment shown, the snare cage 5 is formed using thermally responsive Nitinol (Registered Trade Mark (RTM)). The thermally responsive Nitinol (RTM) cage 5 is inserted into the patients stomach in the manner previously described. Instead of expanding through resilience on deployment from the flexible tube, the Nitinol (RTM) cage 5 expands once it is heated to a predetermined temperature. The expanding temperature of the Nitinol (RTM) may be set during the manufacturing process and for the purposes of the medical device this temperature will typically be in the range of between 200C and 300C. Alternatively, the expanding temperature could be in the range between 2O0C and 37°C. The wires are also pre-bent in the manufacturing process. Once the Nitinol (RTM) is heated up to this temperature, the Nitinol (RTM) will reform into the open cage configuration. It is envisaged that in order to heat the Nitinol (RTM) cage up to a sufficient temperature, the cage 5 may be deployed from the tube 2 and then placed up against the internal wall of the patient's stomach where it will be gradually heated to the desired temperature. The cage 5 will then expand and be ready to snare a wire (not shown) inserted into the patient's stomach.
The thermally expanding cage shown comprises four wires, 41 , 42, 43, and 44, each of which is crimped at knee joints to form a substantially rectangular cage loop with an opposing wire. All of the wires combined will form a substantially box-like configuration of cage. It will be understood however that more or less than four wires could be provided. The wires are joined at each end by stainless steel joints 13, 14. The pusher cable 46 is a stainless steel flexible cable. It is envisaged that this cable may be wound stainless steel. In the embodiment shown, the cage 5 expands outwards to a length of between 10 and 12 cm and a width of between 8 and 10 cm.
It will be understood that in the embodiments described, the cage and the cable were formed integrally with each other. This need not be the case and the two may be formed separately and connected at the weld joint 13. The cage in the embodiment shown consists of four separate cage bars 15(a) to 15(d) constructed from four separate wires. It will also be understood that the number of cage bars need only be two, three, four or more in order to trap the guide wire but four has been found to be quite efficient for the purposes of catching the wire. It is further envisaged that the cage bars could be formed by a single length of cable led back on itself a number of times to form the cage. In the embodiments shown, a rod has been used to manipulate the snare in the flexible delivery tube. It will be understood that any other device for paying out and reeling in the cable could be used and this device could typically be in the form of a handle and trigger arrangement connected to the end of the tube. A detachable mechanical hand powered driver could be used to manipulate the cable in the flexible delivery tube. The snare may be constructed using stainless steel wire, a strengthened plastic material, nitinol or other equivalent material.
It will be understood that the use of large diameter pull gastronomy tubes will allow the use of jejunal extension feeding tubes when warranted via these larger bore gastronomy tubes. Preferably, a 16F gauge or 18F gauge tube is used for the delivery tube, as these are narrow enough to be placed relatively comfortably for the patient, without requiring sedation of the patient. Secondly, there is a lesser tendency for the tube to become blocked when being inserted into the patient. Smaller gauge tubes could also be used in the procedure if desired.
Throughout this specification, reference is made to a flexible delivery tube 2. It will be understood by the skilled addressee reading the specification that the flexible delivery tube is in no way whatsoever intended to encompass an endoscope tube and specifically, an endoscope tube is disclaimed. It is one of the objects of the present invention to obviate the use of an endoscope in such procedures and to overcome the problems associated with the use of the endoscope such as the expense and frequent unavailability of an endoscope. Therefore, it will be understood that throughout the description and claims, any reference to a flexible delivery tube specifically excludes an endoscope tube.
Furthermore, throughout the specification the terms weld joints, crimp joints, welds and the like have been used interchangeably. It would be understood however by the skilled addressee that certain materials, such as nitinol, may not be able to be "welded" in their thermally preconditioned states and would in fact be connected to other components, i.e. the cable 4, by a crimp joint or other suitable connection. It would however be possible to weld the stainless steel if that was the material used for the configurable cage. Therefore, generally speaking, the type of connection will in fact be dictated to a large extent by the materials used for the configurable cage and when nitinol is used for the configurable cage, it will be connected to the cable by a crimp joint or other suitable joint other than a weld joint.
Throughout this specification, and in particular in the introduction and description, the terms X-ray and fluoroscopic guidance have often been used interchangeably although it will be understood that they are distinct. It will be known in the art that fluoroscopy is in fact a continuous low radiation dose method of guiding a procedure.
In the specification the terms "comprise, comprises, comprised and comprising" or any variation thereof and the terms "include, includes, included and including" or any variation thereof are considered to be totally interchangeable and they should all be afforded the widest possible interpretation and vice versa.
The invention is in no way limited to the embodiments hereinbefore described, but may be varied in both construction and detail within the scope of the claims.

Claims

Claims:
1 ) A gastronomy tube placement device (1 ) comprising a flexible delivery tube (2) and a snare (3) housed substantially within the flexible delivery tube (2), the snare (3) further comprising a length of cable (4) having a configurable cage (5), at least part of which is radio-opaque to allow detection of the configurable cage (5) using X-ray guidance, connected to a distal end (6) thereof, the length of cable (4) and configurable cage (5) being slidably moveable with respect to the flexible delivery tube (2) to allow the configurable cage (5) to be moved to and from a position substantially internal the flexible delivery tube (2) and a position substantially external the flexible delivery tube (2), the configurable cage (5) adopting a collapsed configuration when housed within the flexible delivery tube (2) and an expanded configuration when located exterior the flexible delivery tube (2), the configurable cage (5) being collapsible on withdrawal internal the flexible delivery tube (2) from a position external the flexible delivery tube (2).
2) A gastronomy tube placement device (1 ) as claimed in claim 1 in which the configurable cage (5) is constructed from a resiliency deformable material.
3) A gastronomy tube placement device (1) as claimed in claim 1 or 2 in which the configurable cage (5) is constructed from a memory-shaped material that assumes a predetermined expanded configuration external the flexible delivery tube (2) on expulsion from the flexible delivery tube.
4) A gastronomy tube placement device (1) as claimed in any preceding claim in which the configurable cage (5) is constructed from a thermally reactive material that assumes a predetermined expanded configuration external the flexible delivery tube (2) on heating above a predetermined transition temperature.
5) A gastronomy tube placement device (1) as claimed in any preceding claim in which the configurable cage (5), in an expanded configuration, is at least 6cm in length and at least 3 cm in width.
6) A gastronomy tube placement device (1) as claimed in any preceding claim in which the configurable cage (5), in an expanded configuration, is at least 8cm in length and at least 4cm in width.
7) A gastronomy tube placement device (1) as claimed in any preceding claim in which the configurable cage (5), in an expanded configuration, is at least 10cm in length and at least 5cm in width.
8) A gastronomy tube placement device (1) as claimed in any preceding claim in which the configurable cage (5) is constructed using a radio-opaque material to allow detection of the configurable cage (5) under X-Ray guidance.
9) A gastronomy tube placement device (1) as claimed in any preceding claim in which the configurable cage (5) is constructed from nitinol.
10) A gastronomy tube placement device (1) as claimed in claim 9 in which the configurable cage (5) is constructed from a combination of nitinol and a second material with a radio-opacity greater than nitinol.
11) A gastronomy tube placement device (1) as claimed in claim 10 in which the configurable cage (5) is constructed from an alloy of nitinol and the second material with a radio-opacity greater than nitinol.
12) A gastronomy tube placement device (1) as claimed in claim 10 in which the configurable cage (5) is constructed from a wire having a core and an outer covering portion surrounding the core, one of the nitinol and the second material with a radio-opacity greater than nitinol forming the core and the other of the nitinol and the second material with the radio-opacity greater than nitinol forming the outer covering portion.
13) A gastronomy tube placement device (1) as claimed in any of claims 10 to 12 in which the second material with a radio-opacity greater than nitinol is platinum.
14) A gastronomy tube placement device (1) as claimed in claim 13 in which the configurable cage (5) comprises between 80% and 98% nitinol, and between 20% and 2% platinum.
15) A gastronomy tube placement device (1) as claimed in any preceding claim in which the configurable cage (5) and the cable (4) are formed integrally as a single unit.
16) A gastronomy tube placement device (1) as claimed in any of claims 1 to 14 in which the configurable cage (5) and the cable (4) are separate components connected together at a crimp joint (13).
17) A gastronomy tube placement device (1) as claimed in any preceding claim in which the flexible tube (2) further comprises one of a nasogastric and an orogastric tube.
18) A gastronomy tube placement device (1) as claimed in any preceding claim in which there is provided an actuating mechanism connected to the proximal end of the cable to facilitate manipulation of the snare (3) within the flexible delivery tube (2) and deployment and retrieval of the configurable cage (5) relative the flexible delivery tube (2).
19) A gastronomy tube placement device (1) as claimed in claim 18 in which the actuating mechanism further comprises a substantially rigid pusher rod (11).
20) A gastronomy tube placement device (1) as claimed in any preceding claim in which the flexible delivery tube (2) is provided with at least one distance marking about its outer surface indicating a predetermined distance from the distal end of the flexible delivery tube (2) to the distance marking.
21 ) A gastronomy tube placement device (1 ) as claimed in claim 4 in which the thermally reactive material has a transition temperature of between 200C and 37° C.
22) A gastronomy tube placement device (1) as claimed in claim 4 in which the thermally reactive material has a transition temperature of approximately
35° C.
23) A gastronomy tube placement device (1) as claimed in any preceding claim in which the flexible delivery tube (2) further comprises a connector (9) mounted on the proximal end of the flexible delivery tube (2), the connector
(9) having an aperture for through passage of the snare and a side port (10) for connection to a gas supply.
24) A gastronomy tube placement device (1) as claimed in any preceding claim in which at least part of the configurable cage (5) is sufficiently radio- opaque to allow detection using fluoroscopic guidance.
25) A method of placement of a gastronomy tube (26) comprising the steps of:
delivering a distal end of a gastronomy tube placement device (1 ) through a patients mouth or nose, along their oesophagus (24) and into the patients stomach (18), the gastronomy tube placement device (1) comprising a flexible delivery tube (2) substantially housing a snare (3), the snare (3) being slidably mounted in the flexible delivery tube (2) and the snare comprising a cable (4) having a configurable cage (5), at least part of which is radio-opaque to allow detection of the configurable cage (5) using X-ray guidance, mounted on the distal end thereof;
once the distal end of the gastronomy tube placement device (1) is in position in the patients stomach (18), sliding the snare (3) along the flexible delivery tube (2) until the configurable cage (5) exits the distal end of the flexible delivery tube (2) and assumes an expanded configuration; taking an X-ray of the patient's abdomen including their stomach (18) containing the deployed expanded configurable cage (5) to determine the location of the configurable cage (5) in the patient's stomach;
inserting a cannula (20) through the patient's abdominal wall in the vicinity of the configurable cage (5);
partially feeding a guide wire (22) through the cannula (20) into and through the configurable cage (5);
retracting the configurable cage (5) back into the flexible delivery tube (2) thereby collapsing the configurable cage (5) and trapping the guide wire in the configurable cage;
withdrawing the distal end of the gastronomy tube placement device (1) from the patient's stomach (18), back through their oesophagus (24) and out through their nose or mouth;
releasing the end of the guide wire (22) from the configurable cage (5) and thereafter tying a gastronomy tube (26) to that end of the guide wire; and
pulling the other end of the guide wire (22) protruding from the patients abdomen so that end of the guide wire with the gastronomy tube (26) attached thereto is drawn through the patients mouth or nose, along their oesophagus (24) and into their stomach (18), and gradually pulling part of the gastronomy tube (26) through the abdominal wall before securing the gastronomy tube (26) in place.
26) A method of placement of a gastronomy tube (26) as claimed in claim 25 in which the method further comprises the intermediate step of pumping gas into the patients stomach (18) along the flexible delivery tube (2) subsequent to placement of the distal end of the delivery tube (2) in the patients stomach (18) and prior to deployment of the configurable cage (5).
27) A method of placement of a gastronomy tube (26) as claimed in claim 25 or 26 in which the method further comprises the intermediate step of removing the cannula (20) from the patient's abdomen prior to pulling the gastronomy tube (26) through the abdominal wall.
28) A method of placement of a gastronomy tube (26) as claimed in any of claims 25 to 27 in which the method further comprises the intermediate step of taking a further X-ray of the patients abdominal region including their stomach (18) containing the configurable cage (5) subsequent to inserting the guide wire (22) through the cannula (20) and prior to retracting the configurable cage (5) back into the flexible delivery tube (2) to ensure that the guide wire has passed through the collapsible cage.
29) A method of placement of a gastronomy tube (26) as claimed in any of claims 25 to 28 in which the configurable cage (5) is constructed from a thermally reactive material that assumes a predetermined expanded configuration external the flexible delivery tube (2) on heating above a predetermined transition temperature and in which the method further comprises the intermediate step of placing the configurable cage (5) in contact against the interior stomach wall of the patient subsequent to expulsion of the configurable cage from the flexible delivery tube to heat the configurable cage to the predetermined transition temperature.
30) A method of placement of a gastronomy tube (26) as claimed in any of claims 25 to 29 inclusive in which the method further comprises the initial step of running a lubricant through the flexible delivery tube (2) prior to insertion into the patient.
31) A method of placement of a gastronomy tube (26) as claimed in any of claims 25 to 30 inclusive in which the method comprises using fluoroscopic guidance instead of X-ray guidance.
PCT/IE2005/000124 2004-11-04 2005-11-04 A gastronomy tube placement device WO2006048853A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IES2004/0737 2004-11-04
IE20040737 2004-11-04

Publications (1)

Publication Number Publication Date
WO2006048853A1 true WO2006048853A1 (en) 2006-05-11

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ID=35464327

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IE2005/000124 WO2006048853A1 (en) 2004-11-04 2005-11-04 A gastronomy tube placement device

Country Status (1)

Country Link
WO (1) WO2006048853A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8974517B2 (en) 2000-12-28 2015-03-10 Abbott Cardiovascular Systems Inc. Thermoelastic and superelastic NI-TI-W alloy

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5112310A (en) * 1991-02-06 1992-05-12 Grobe James L Apparatus and methods for percutaneous endoscopic gastrostomy
US5902238A (en) * 1993-09-14 1999-05-11 University Of Washington Medical tube and apparatus for locating the same in the body of a patient
US6093179A (en) * 1998-01-21 2000-07-25 Abbott Laboratories Apparatus and method for placement of a percutaneous endoscopic gastrostomy tube

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5112310A (en) * 1991-02-06 1992-05-12 Grobe James L Apparatus and methods for percutaneous endoscopic gastrostomy
US5902238A (en) * 1993-09-14 1999-05-11 University Of Washington Medical tube and apparatus for locating the same in the body of a patient
US6093179A (en) * 1998-01-21 2000-07-25 Abbott Laboratories Apparatus and method for placement of a percutaneous endoscopic gastrostomy tube

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8974517B2 (en) 2000-12-28 2015-03-10 Abbott Cardiovascular Systems Inc. Thermoelastic and superelastic NI-TI-W alloy

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