Endoscope system for gastrostomy catheter placement

An instrument for confirming the position of an indwelling gastrostomy catheter, and a method of confirming the indwelling position thereof, with which it is possible to reduce cleaning costs, and which does not cause any discomfort to a patient. An instrument for confirming the indwelling position of a gastrostomy catheter which is indwelling in a hole formed between the surface of the skin of the patient and the inner surface of the stomach wall comprising a fiberscope and a protective cover. Furthermore, the tip end of the protective cover comprises a light-transmissive window part and a wire that is linked to the outer periphery at the tip end of the protective cover.

FIELD OF THE INVENTION

The present invention relates to an instrument for confirming the position of an indwelling gastrostomy catheter which is used when a gastrostomy catheter is made indwelling in a patient's body in order to supply fluid such as nutrients and food in fluid form to the patient's stomach, and to a method of confirming the indwelling position.

BACKGROUND OF THE INVENTION

Fluids such as nutrients and food in fluid form are conventionally supplied to people having a reduced capacity for ingesting food orally by themselves due to advanced age or illness (referred to hereinafter as “patients”) using a gastrostomy catheter. Such a gastrostomy catheter is provided with a stomach-internal fixed part which is arranged on the inner part of the stomach wall in a hole (gastrostomy hole) for ingestion which is provided in the abdomen of the patient, and a tubular part of which the tip end is linked to the stomach-internal fixed part, and the base end passes through the hole and extends outside the patient's body. When this gastrostomy catheter is attached at the hole which is formed in the patient's body, it is then necessary to confirm whether or not the stomach-internal fixed part of the gastrostomy catheter is indwelling in the correct state inside the stomach.

One method of confirming the indwelling position of the gastrostomy catheter in this case is a method in which an endoscope is inserted into the alimentary canal orally or nasally, and observations are made using the endoscope. There is also another method in which the gastrostomy catheter is made indwelling in the hole in the patient, after which fluid etc. inside the body is sucked out from the gastrostomy catheter by means of a syringe, and the indwelling position of the gastrostomy catheter is confirmed according to the characteristics of the fluid sucked out. With these methods, there are problems with the one in which suction is carried out using a syringe after the gastrostomy catheter has been made indwelling in that it is difficult to judge unless there are marked differences in the characteristics of the fluid etc. sucked out, which leads to poor reliability. Consequently, the method employing an endoscope is preferred in order to more reliably confirm the indwelling position. However, there are problems with the method employing an endoscope such as the high costs of cleaning the endoscope after use and patient discomfort.

In view of these problems, it is possible to significantly reduce the costs of cleaning the endoscope after use by attaching a disposable cover to the endoscope (see, for example, Japanese Unexamined Patent Application Publication H3-292925). This endoscope probe cover (protective cover) is made up of a tube which covers the endoscope probe very closely, and a thread-like body, and it has a structure in which it is possible to split the tube after use by pulling the thread-like body. Consequently, the endoscope probe does not come into direct contact with fluids etc. in various parts of the body and become soiled, which makes sterilizing and cleaning operations largely unnecessary, and therefore the costs entailed by sterilizing and cleaning can be reduced.

However, with the endoscope probe cover described above, there is a risk that soiling adhering to the surface of the tube will then adhere to the endoscope probe when the thread-like body is pulled and the tube is split. In this case also, there are still problems remaining in that if the endoscope probe is inserted into the alimentary canal orally or nasally, this causes discomfort to the patient when the endoscope probe is inserted.

SUMMARY OF THE INVENTION

One embodiment of the present invention is an instrument for confirming the position of an indwelling gastrostomy catheter which comprises a tubular part for running through a hole which is formed between the surface of the skin of a patient and the inner surface of the stomach wall, and extending from outside the patient's body to the inner surface of the stomach wall, and a stomach-internal fixed part capable of linking to the tip end of the tubular part and being arranged at the inner surface of the stomach wall, the fixed part having a through-hole adapted to receive the tubular part therethrough said instrument comprising a fiberscope, with which it is possible to observe the inner surface of the stomach wall, adapted to run through the inside of the tubular part so that the tip end thereof projects from the through-hole of the stomach-internal fixed part, and a protective cover adapted to pass through the gastrostomy catheter together with the fibrescope, in a state in which the fibrescope is covered, the cover including a light-transmissive window part at a tip end thereof which allows observation of the inner surface of the stomach wall by means of the fiberscope.

Another aspect of this invention is an inventive method of confirming the position of an indwelling gastrostomy catheter which comprises a tubular part for running through a hole which is formed between the surface of the skin of the patient and the inner surface of the stomach wall, and extending from outside the patient's body to the inner surface of the stomach wall, and a stomach-internal fixed part capable of linking to the tip end of the tubular part and being arranged at the inner surface of the stomach wall, the fixed part having a through-hole adapted to receive the tubular part therethrough said method comprising: making the gastrostomy catheter indwelling, in which the gastrostomy catheter is made indwelling in the hole; covering the fibrescope, in which the fibrescope is covered by a protective cover; inserting the fiberscope covered by the protective cover inside the tubular part, with the tip end portion thereof projecting from the through-hole of the stomach-internal fixed part; confirming the indwelling position, in which the inner surface of the stomach wall observed by means of the fibrescope is checked; withdrawing the fibrescope, in which the fibrescope which has been covered by the protective cover is withdrawn from the gastrostomy catheter; and removing the protective cover, in which the fibrescope is withdrawn from the protective cover.

DESCRIPTION OF FIGURE NOTATIONS

DETAILED DESCRIPTION OF THE INVENTION

One embodiment of the present invention will be described below with reference to the figures.FIG. 1shows a gastrostomy catheter10pertaining to this mode of embodiment, andFIG. 2shows an instrument20for confirming the indwelling position in order to confirm the indwelling position of the gastrostomy catheter10. The gastrostomy catheter10comprises an external fixed part11, a tubular part12which is linked to the centre of the lower end surface of the external fixed part11, and a stomach-internal fixed part13which is attached to the lower end of the tubular part12, all these components being made of a soft plastic material such as polyurethane or silicone. In the description that follows, the external fixed part11will be taken as the upper side, and the stomach-internal fixed part13will be taken as the lower side.

The external fixed part11comprises an insertion opening11awhich is annular and fairly thick, and projecting pieces11b,11cof which the outline is elliptical and includes the insertion opening11a, these pieces projecting at both sides from the lower end of both side parts of the insertion opening11a, when seen as a plane. The function of these projecting pieces11b,11cis to prevent the gastrostomy catheter10from being pulled into the stomach S (seeFIGS. 6 to 8). A valve body14awhich is formed with a central slit is then provided on the inner peripheral surface of an insertion hole14which is formed in the centre of the insertion opening11a, passing through vertically. Furthermore, an engagement groove is formed along the circumference at the upper side of the valve body14aon the inner peripheral surface of the insertion hole14, although this is not depicted. A cover part15for closing off the insertion hole14of the insertion opening11ais then joined to the tip end side of the projecting piece11b.

The cover part15comprises an elongate strip-shaped linking part15awhich is linked to the end part of the projecting piece11b, and a broad part15bwhich is shorter and wider than the strip-shaped linking part15a, and is formed at the tip end of the strip-shaped linking part15a. A stopper part16shaped like a column which is short in the axial direction is then provided on the broad part15b. The strip-shaped linking part15ais flexible, and it can flex so as to vertically rotate, or bend at a sharp angle, with the linking part to the projecting piece11bat the centre. The stopper part16is provided on the strip-shaped linking part15aside portion of the broad part15b, so as to face the insertion hole14when the strip-shaped linking part15ais bent to position the broad part15babove the insertion opening11a.

The stopper part16is formed with a columnar shape which can fit into the insertion hole14, and it is provided on its outer peripheral surface with an annular projection16arunning along its periphery, this projection being able to detachably engage with the engagement groove formed on the inner peripheral surface of the insertion hole14. Accordingly, it is possible to engage the engagement groove with the annular projection16aby bending the strip-shaped linking part15aso that it is upwardly inverted, and pushing the stopper part16into the insertion hole14, and this makes it possible to close off the insertion hole14of the insertion opening11ain an airtight manner. It is also possible to open the insertion hole14of the insertion opening11aby pulling the broad part15bto release the fitting between the stopper part16and the insertion hole14.

The tubular part12is formed as a cylindrical shape, and a supply channel (not depicted) for allowing the passage of fluids such as nutrients and food in fluid form is formed inside it; the upper end of the supply channel links in communication with the insertion hole14of the external fixed part11. The stomach-internal fixed part13is connected to the tubular part12via a connection part17which is fixed to the lower end of the tubular part12. Said connection part17is formed as a cylinder for covering the outer peripheral surface of the tubular part12and is integrally formed with the stomach-internal fixed part13. Said connection part17is then attached to the lower end of the tubular part12, in a state in which it cannot be removed from the tubular part12.

The stomach-internal fixed part13comprises four strip-shaped linking parts13awhich are linked to the edge of a lower end opening of the connection part17and extend in four directions, four linking film parts13bwhich are provided between the upper parts of each of the linking parts13aand form a roughly dome-shaped stomach wall contact part with the four linking parts13a, and a converging part13cwhere the tip ends of all of the linking parts13aconverge. The four linking parts13acomprise strip-shaped members which are bent into substantially semi-circular shapes which split into four directions from the lower end of the connection part17, respectively extending downwards from the horizontal, after which they converge below the central axis of the tubular part12, linking to form the converging part13c. That is to say, the converging part13callows each of the linking parts13ato link by joining the lower ends of all of the linking parts13a, and it is also positioned by all of the linking parts13abelow the central axis of the tubular part12.

Moreover, the stomach-internal fixed part13which comprises the linking parts13a, linking film parts13band the converging part13cis integrally formed together with the connection part17. Furthermore, all of the linking parts13aand linking film parts13bare made of a soft, flexible, elastic material, and the overall roughly spherical shape is normally maintained by means of this elasticity, as shown inFIG. 1, but the shape can be extended to make it straight and elongate by pulling the converging part13cdownwards. Furthermore, spaces formed between the lower parts of each of the linking parts13aform channels for the passage of fluids such as nutrients and food in fluid form sent out from the supply channel of the tubular part12into the stomach S. A through-hole18is additionally formed in the centre of the converging part13c. The stomach-internal fixed part13configured in this manner is positioned on the inner surface of the patient's stomach wall SW (seeFIGS. 6 to 8) and its function is to prevent the gastrostomy catheter10from being removed from the patient's body.

As shown inFIGS. 2 to 4, the instrument20for confirming the indwelling position comprises a fibrescope23which has a configuration in which a lens21is attached to the tip end of a fibrescope shaft23aand a connecting part22is attached to the rear end thereof, a protective cover24, and a connection fitting25. As shown inFIG. 5, the fibrescope shaft23ais flexible and it is configured by a bundle of fibres comprising a plurality of light guides23bfor irradiating light onto the stomach wall SW, and an image guide21afor sending images via the lens21. The connection part22is connected to wiring22afor connecting the image guide21ato an image display device (not depicted), and wiring22bfor connecting the light guides23bto a light source device (not depicted).

The lens21sends images obtained by the irradiation of the light guides23bto the image display device, via the image guide21aand the wiring22a. In other words, the light guides23birradiate the inner surface of the stomach wall SW with light sent from the light source device to make observation possible, and the image guide21asends the light which is reflected from the inner surface of the stomach wall SW and focused by means of the lens21to the image display device. The image display device then enlarges the images sent and displays them on an image display part provided in the image display device.

Furthermore, the protective cover24is flexible and is such that its tip end is closed off by a light-transmissive window part24a, and its base end24bon the opening side is configured by a tube of somewhat larger diameter than the other portions. Said protective cover24is formed to be of a thickness which can cover and fix the fibrescope shaft23a, and it is prevented from being removed from the fibrescope shaft23aby inserting a tip-end narrow-diameter part22cof the connection part22into the base end24b. In this state, the instrument is configured so that the lens21is in contact with the inner surface of the window part24a.

Furthermore, the tip end of a wire24cwhich acts as the linear member pertaining to the present invention is fixed to the edge of the window part24aon the outer peripheral surface of the protective cover24. A wire lumen (not depicted) for the passage of the wire24cthrough the lower end region of the base end24bis formed from a portion of specified length (the length required to bend the protective cover24) above the tip end on the peripheral surface of the protective cover24. The wire24cextends upwards and outside of the tip end of the protective cover24, after which it passes through inside the wire lumen and extends outside.

The connection fitting25is attached to the gastrostomy catheter10to provide smoother insertion of the protective cover24etc. into the gastrostomy catheter10, and it is configured by a connection part26, insertion opening27and an air supply opening28. The connection part26is configured by a substantially cylindrical engagement part26bwhich is formed in the centre of the lower surface of an annular connection part main body26a, and an insertion hole for allowing the insertion of the protective cover24is formed therein. Furthermore, the connection part main body26ais formed with an annular shape which is substantially the same size as the insertion opening11aof the gastrostomy catheter10, and the engagement part26bis formed with a cylindrical shape having four different levels.

The engagement part26bis made up of an uppermost level in which the outer peripheral surface which has a larger diameter at its upper part than its lower part has an oblique surface, a second level which has the same diameter as the lower part of the uppermost level, a third level which has substantially the same diameter as the upper part of the uppermost level, and a lowermost level in which the outer peripheral surface which has substantially the same diameter as the second level at its upper part, and a smaller diameter at its lower part than its upper part has an oblique surface. The third level of the engagement part26bconfigures an annular projection26cwhich is able to detachably engage with the engagement groove formed in the insertion hole14of the gastrostomy catheter10, and when the annular projection26cengages with the engagement groove, a state of air-tightness is achieved between the engagement part26band the peripheral surface of the insertion hole14.

The insertion opening27is formed with a cylindrical shape and an insertion hole enabling the insertion of the protective cover24is formed therein, an annular reinforcing rib27abeing formed on the edge of the opening at the upper end. Furthermore, the insertion hole formed inside the insertion opening27and the insertion hole formed inside the connection part26have the same diameter and are also coaxially linked in communication. The air supply opening28is formed as a cylindrical shape extending obliquely upwards from the lower end of the insertion opening27in a state in which it is inclined at approximately 45° to the insertion opening27, and it is narrower in diameter than the insertion opening27. An annular reinforcing rib28ais furthermore formed on the edge of the opening at the upper end of the air supply opening28.

An air supply device (not depicted) is connected to the reinforcing rib28aof said air supply opening28, and air which is supplied from the air supply device passes through inside the air supply opening28and is sent to the lower end inside the insertion opening27. Furthermore, an airflow channel (not depicted) for allowing the passage of air is formed between the lower end inside the insertion opening27and the lower end inside the connection part26; air sent to the lower end inside the insertion opening27is released to the outside from the lower end of the connection part26.

A substantially triangular sheet-like reinforcing grip part29for strengthening the area between the insertion opening27and the air supply opening28and also for facilitating holding of the connection fitting25with the hand is formed between the insertion opening27and the air supply opening28. The instrument20for confirming the indwelling position shown inFIG. 2is assembled by covering the fibrescope shaft23awith the protective cover24, and by passing the protective cover24etc. in this state together with the wire24cthrough the insertion hole formed inside the insertion opening27and the connection part26of the connection fitting25.

A description of the method of confirming the indwelling position of the gastrostomy catheter10using the instrument20for confirming the indwelling position configured in the manner described above will be given next, with reference toFIGS. 6 to 8.FIG. 6shows a state in which the gastrostomy catheter10is indwelling in a hole provided in the abdominal wall AW and the stomach wall SW of a patient, where said gastrostomy catheter10is made indwelling in the hole using a specific instrument for fitting it. A description of the structure and the method of making this fitting instrument indwelling will be omitted here. In the state shown inFIG. 6, the stopper part16of the gastrostomy catheter10is removed from the insertion hole14to open the upper end of the insertion hole14. Furthermore, the instrument20for confirming the indwelling position is positioned above the gastrostomy catheter10, and the instrument20for confirming the indwelling position which is in this state is moved down in the direction of the arrow in the figures so that the protective cover24projecting from the lower end of the connection fitting25is inserted into the insertion hole14of the gastrostomy catheter10together with the fibrescope23.

At this time, an operator holds both sides of the insertion opening11aon the gastrostomy catheter10with one hand, and holds the reinforcing grip part29of the connection fitting25with the other hand, and pushes the connection fitting25into the gastrostomy catheter10. As shown inFIG. 7, this makes it possible to engage the connection fitting25with the gastrostomy catheter10. The engagement in this case is brought about by the engagement of the annular projection26cof the connection fitting25with the engagement groove of the gastrostomy catheter10, and a state of air-tightness is achieved between the connection fitting25and the gastrostomy catheter10. The protective cover24is then further inserted towards the lower side of the gastrostomy catheter10together with the fibrescope23, and the lower portion of the protective cover24projects downwards from the through-hole18formed at the lower end of the gastrostomy catheter10. It should be noted that the protective cover24and the fibrescope23may pass inside the connection fitting25after the connection fitting25has been connected to the gastrostomy catheter10.

Next, air is supplied from the air supply device to inside the air supply opening28, and this air is sent into the stomach S from the connection part26via the tubular part12of the gastrostomy catheter10. This allows the stomach S to expand, as shown inFIG. 8. In this state, light is generated by means of the light source device, whereby light passes through the wiring22band the light guides23bof the fibrescope shaft23a, and is irradiated towards the stomach wall SW, as shown inFIG. 8. Furthermore, in this case, the tip end portion of the protective cover24can be made to flex together with the fibrescope shaft23aso that it is possible to change the position of irradiation of the stomach wall SW by the light guides23b, and this is achieved by pulling the wire24c, as required.

The range shown by the two-dot chain line inFIG. 8shows the range of light irradiation by the light guides23b. Light which is irradiated by means of the light guides23band reflected off the stomach wall SW is focused by the lens21, after which it is sent to the image display device by way of the image guide21aand the wiring22aof the fibrescope shaft23a. Images which are sent to the image display device are enlarged in the image display part of the image display device, and therefore it is possible to confirm whether or not the stomach-internal fixed part13of the gastrostomy catheter10is positioned in the correct state inside the stomach S, from the images displayed in said image display part. If it is possible to confirm that the gastrostomy catheter10is indwelling in the correct state, an operation is carried out in which the instrument20for confirming the indwelling position is removed from the gastrostomy catheter10, and also the protective cover24is removed from the fibrescope shaft23a.

In this operation, the protective cover24is first of all pulled upwards together with the fibrescope23in a state in which the force pulling on the wire24chas been released, and then in the state shown inFIG. 7, the engagement between the annular projection26cof the connection fitting25and the engagement groove of the gastrostomy catheter10is released. The protective cover24and the fibrescope23are then removed from the gastrostomy catheter10by pulling them upwards together with the connection fitting25. In addition, the connection fitting25is removed from the protective cover24etc., after which the fibrescope shaft23aetc. is pulled out of the protective cover24. The protective cover24is then disposed of, and the fibrescope23can be reused next time.

At this time, the lens21and the fibrescope shaft23ado not come into contact with the liquids and residues inside the patient's body and stomach S, so they are not soiled and there is no need for the most part to clean or sterilize them. Furthermore, when the fibrescope23is reused, the fibrescope shaft23ais covered with a new protective cover24. Moreover, in the operation described above, the engagement between the annular projection26cof the connection fitting25and the engagement groove of the gastrostomy catheter10is released, and the protective cover24and the fibrescope23are removed from the gastrostomy catheter10together with the connection fitting25, but it is also possible to remove the protective cover24etc. from the connection fitting25, and then to release the engagement between the annular projection26cof the connection fitting25and the engagement groove of the gastrostomy catheter10.

Furthermore, when nutrient fluid is supplied to the patient's stomach S, for example, by way of the gastrostomy catheter10which is indwelling in the patient's body, a connector for a tube extending from a container housing the nutrients is connected to the insertion hole14of the gastrostomy catheter. In this state, nutrients are supplied to the patient by way of the tube and the gastrostomy catheter10. At this time, nutrients coming out of the tubular part12pass from the stomach-internal fixed part13through each of the linking parts13a, and enter the stomach S. Furthermore, after use, the tube from the container of nutrients is removed from the insertion hole14of the gastrostomy catheter10, and the insertion hole14is closed using the stopper part16. Then, when it becomes necessary to replace the gastrostomy catheter10after regular periods of use, it can be replaced with a new gastrostomy catheter10. In this case also, the indwelling position of the gastrostomy catheter10can be confirmed using the instrument20for confirming the indwelling position which has been described above.

In this way, the inventive instrument20for confirming the indwelling position of a gastrostomy catheter is provided with a protective cover24, and the fibrescope shaft23ais covered by this protective cover24, and they pass through the gastrostomy catheter10. Consequently, there is no discomfort for the patient caused by the fitting of the fibrescope23and the protective cover24to the patient's body. Furthermore, after the indwelling position of the gastrostomy catheter10has been confirmed, the fibrescope23etc. are pulled out from the gastrostomy catheter10, and then the fibrescope23is pulled out from the protective cover24, whereby the fibrescope shaft23adoes not become soiled with gastric juices etc.

As a result, there is virtually no need to clean or sterilize the fibrescope23, making expenses for sterilization and cleaning largely unnecessary, and also making it possible to extend the lifespan of the fibrescope23. Furthermore, the wire24cis linked to the tip end of the protective cover24, and the tip end of the protective cover24projects from the through-hole18of the stomach-internal fixed part13, and in this state the tip end portion of the protective cover24can be made to flex together with the fibrescope shaft23aby pulling the wire24cso that it is possible to change the direction of irradiation by the light guides23band the direction of focus of the lens21. This means that it is possible to change the direction of irradiation and the direction of focus with a simple operation, and it is possible to more reliably confirm the indwelling position.

Furthermore, the inventive instrument for confirming the indwelling position of a gastrostomy catheter is not limited to the embodiment described above, and appropriate modifications may be implemented within the technical scope of the present invention. For example, in the embodiment described above, an external fixed part11is provided on the gastrostomy catheter10, but a gastrostomy catheter which is not provided with an external fixed part11may also be used. In this case the connection fitting25may also be dispensed with. It is also possible to use other devices having similar functions instead of the image display device and light source device, etc. In addition, in the embodiment described above, the tip end portion of the protective cover24is made to flex together with the fibrescope shaft23aby pulling the wire24c, but the wire24cmay be configured by a rigid material, and the tip end portion of the protective cover24may be made to flex together with the fibrescope shaft23aby pushing the wire24c.

With the present invention configured in the manner described above, the fiberscope which is used as an endoscope may be covered by a protective cover and passed through inside the gastrostomy catheter. In this way, the fiberscope is inserted together with the protective cover from the gastrostomy catheter which is already indwelling in the patient's body, reaching the inner surface of the stomach wall, and therefore there is no discomfort for the patient caused by the insertion of the fiberscope and the protective cover. Furthermore, it is possible to reduce the diameter of the endoscope by using a fiberscope as the endoscope, as a result of which the endoscope passes through the gastrostomy catheter more easily.

Furthermore, when the indwelling position of the gastrostomy catheter is confirmed, the protective cover and the fiberscope can then be pulled out of the gastrostomy catheter together, after which the fiberscope is pulled out of the protective cover, whereby the fiberscope can be removed from the patient's body without any soiling of the fiberscope with gastric juices etc. As a result, there is virtually no need to clean or sterilize the fiberscope, making expenses for sterilization and cleaning largely unnecessary, and also making it possible to extend the lifespan of the fiberscope. In addition, the tip end of the protective cover facing the tip end of the fiberscope consists of a window part which allows light transmission, and therefore there is no reduction in the observational accuracy of the stomach wall by the fiberscope due to the protective cover.

Another aspect of one embodiment of the present invention is that when a linear member is linked to the outer periphery at the tip end of the protective cover, and the tip end of the protective cover is projecting from the through-hole of the stomach-internal fixed part, the tip end portion of the protective cover can be made to flex together with the fiberscope so that it is possible to change the observation direction of the fiberscope, by operation of the rear end portion of the linear member. By virtue of this, it is possible to change the direction of observation of the lens using a simple operation, and this makes it possible to confirm the indwelling position more reliably. In this case, it is possible to confirm the direction of the through-hole of the stomach-internal fixed part using the fiberscope. Furthermore, the fiberscope is such that it flexes under the action of the protective cover, and therefore the fiberscope itself can be made with a simple structure. Because of this, it is possible to reduce the number of components of the fiberscope itself which might break down. The operations of the rear end portion of the linear member in this case include pushing and pulling operations of the linear member.