Endoscope insertion aid

Abstract

To provide an aid for endoscope insertion capable of reliably and easily arranging the opening so as to be directed to the duodenal papilla with a simple configuration.SOLUTION: An overtube 1 for a small diameter endoscope insertion is used for covering an insertion part 21 of a small diameter endoscope 20, and guiding the insertion part 21 into the common bile duct of a subject through the duodenal papilla of the subject, and includes: a flexible curved cylindrical body 10 that holds a predetermined curvature in a state of being placed on a horizontal surface; and a side wall opening 12 formed on a side wall on a center C side that defines the curved shape on an axial tip side of the cylindrical body 10 for deriving the tip of the insertion part 21. The side wall opening 12 is provided at a position with a predetermined inclination angle in a circumferential direction with respect to the horizontal surface of the peripheral surface of the cylindrical body 10.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an endoscope insertion aid used to guide the insertion portion of a thin endoscope into a lumen of a subject. [Background technology]

[0002] In recent years, with growing interest in minimally invasive medical treatment, endoscopic examination and treatment for biliary and pancreatic diseases have become widespread.

[0003] However, because the bile duct and pancreatic duct run in a direction that intersects with the duodenum at a steep angle and their inner diameters are thinner than those of general endoscopes (endoscopes with an outer diameter of the insertion part of approximately 10 mm, such as duodenoscopes and upper gastrointestinal endoscopes), a normal endoscope cannot be inserted into the bile duct or pancreatic duct, resulting in the problem that the inside of the bile duct or pancreatic duct cannot be directly visualized.

[0004] In response to such problems, it has been proposed to insert an endoscope, the outer diameter of which is preferably about 6 mm, into the bile duct using an endoscope insertion aid that includes a cylindrical body through which the insertion part of the endoscope is inserted, an opening that is provided at the tip of the cylindrical body and opens into the side wall, and an inflatable and deflated balloon located distal to the opening of the cylindrical body (see Patent Document 1). With this endoscope insertion aid, the insertion part covered with the cylindrical body is inserted to a desired position in the body cavity, and then the balloon is inflated to bring the side wall opening into close contact with the inner wall of the body cavity, thereby holding the side wall opening in a desired position (for example, a position facing the duodenal papilla). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Unexamined Patent Publication No. 62-22623 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the endoscope insertion aid described in Patent Document 1 sometimes did not position the opening of the tubular body toward the duodenal papilla. This type of general aid is made of a flexible material, and torque applied to the base end of the aid is not easily transmitted to the tip end, so it is difficult to adjust the opening located at the tip end to face the duodenal papilla by twisting the base end. Therefore, once the aid is inserted, it is difficult to adjust the position of the opening, and if the opening does not face the duodenal papilla, it is necessary to remove the endoscope and aid from the body, adjust the direction of the opening, and then insert it back into the body again, repeating this action until the opening faces the duodenal papilla.

[0007] Furthermore, if the opening of the tubular body is not positioned toward the duodenal papilla, the endoscope cannot be inserted into the bile duct, which poses the problem that endoscopic examination and treatment cannot be performed.

[0008] In recent endoscopic examinations, for example, as shown in Fig. 13(a), a specially thinned endoscope (cholangioscope) 31 for bile duct insertion, with an insertion part outer diameter of about 3.5 mm, is inserted into the bile duct like a catheter through a predetermined channel of a general endoscope 30 (side-viewing endoscope) to observe the inside of the bile duct. This method inevitably requires a complex structure of the endoscope 31 and high costs, and the field of view is narrower than that of a general-purpose thin endoscope 20 with an insertion part outer diameter of about 6 mm shown in Fig. 13(b), and high resolution images cannot be expected. For this reason, in recent years, an auxiliary tool capable of supporting direct insertion of a general-purpose thin endoscope 20 with a wider field of view and better image resolution than a specially thinned cholangioscope 31 into the bile duct has been awaited.

[0009] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide an endoscope insertion aid that has a simple configuration and can be reliably and easily positioned so that its opening faces the duodenal papilla. [Means for solving the problem]

[0010] In order to achieve the above-mentioned object, the endoscope insertion aid of the present invention is an endoscope insertion aid for guiding the insertion portion of an endoscope into a lumen of a subject, and is configured to have a flexible, curved tubular body that maintains a predetermined curvature when placed on a specified plane and has a hole extending in the axial direction through which the insertion portion can be inserted, and an opening formed in a central side wall that defines the curved shape at the axial tip side of the tubular body, and through which the tip of the insertion portion can be guided out.

[0011] The endoscope insertion aid according to the present invention can be realized by a simple structure in which a cylindrical body is formed into a curved shape using a flexible material and an opening is provided in a central side wall that defines the curved shape. In addition, in this endoscope insertion aid, the curved shape of the cylindrical body is designed to fit well in a human stomach and to have a fixed fitting posture, and the position of the opening is set taking into consideration the position (fitting position) of the duodenal papilla relative to the cylindrical body in the fitting posture of a human, so that the opening of the cylindrical body can be easily positioned to face the duodenal papilla when the aid is placed over the insertion part of an endoscope and guided to the back of the duodenum.

[0012] The endoscope insertion aid according to the present invention may be configured so that the opening is provided at a position having an inclination angle of 0° to 90° in the circumferential direction of the cylindrical body with respect to the specified plane on the surface of the cylindrical body.

[0013] The endoscope insertion aid according to the present invention can be positioned so that the opening of the tubular body naturally faces the duodenal papilla in the process of covering the insertion part of the endoscope and guiding it to the back of the duodenal papilla by setting the inclination angle of the opening in the circumferential direction of the tubular body in accordance with the position of the duodenal papilla starting from the position where the tubular body fits in the stomach. Furthermore, the tip of the insertion part can then be easily led out of the opening and inserted into the duodenal papilla, and the insertion part can then be easily guided from there into the common bile duct.

[0014] In the endoscope insertion aid according to the present invention, the opening may be configured such that, when the diameter (outer diameter) of the outer periphery of the tubular body is a, it has a length of 1.0a to 2.0a in the axial direction of the tubular body and a depth of 0.3a to 0.7a from the outer periphery.

[0015] With this configuration, the endoscope insertion aid of the present invention has an opening that is large compared to the size of the tubular body, so that the operation of guiding the insertion portion of the endoscope out and the operation of pushing it forward can be performed reliably and easily.

[0016] The endoscope insertion aid according to the present invention may also be configured to have an inflatable and deflated balloon provided along the circumferential surface of the cylindrical body on the distal end side relative to the opening.

[0017] With this configuration, the endoscope insertion aid of the present invention can easily guide the tip of the insertion part of the endoscope led out from the opening to the duodenal papilla by abutting the tip of the insertion part against the inflated balloon and changing its direction.

[0018] In the endoscope insertion aid according to the present invention, the balloon may be configured such that inflation is restricted on a peripheral surface of the tubular body opposite to a side on which the opening is formed.

[0019] With this configuration, the endoscope insertion aid of the present invention makes it easy to provide the space between the opening and the duodenal papilla that is necessary to curve the tip of the endoscope's insertion portion toward the duodenal papilla by inflating the balloon with the opening facing the duodenal papilla, making it possible to more easily guide the endoscope's insertion portion toward the duodenal papilla.

[0020] The endoscope insertion aid according to the present invention may further include a medium flow path formed on the surface of the tubular body along the axial direction, for supplying a medium for inflating and deflating the balloon, and an opening and closing valve for the medium flow path.

[0021] With this configuration, the endoscope insertion aid of the present invention allows the practitioner to operate the opening / closing valve at hand and easily inflate the balloon in time with the timing of leading the insertion portion of the endoscope out of the opening.

[0022] The endoscope insertion aid according to the present invention is used for covering the insertion portion of the endoscope and guiding the insertion portion to the bile duct via the duodenal papilla of the subject, and the tubular body is formed in a curved shape that easily fits into a key portion of the inner wall of a human stomach, and the opening has a circumferential inclination angle set so that the opening is positioned facing the duodenal papilla when the subject's duodenum is changed in position and the tubular body is fitted within the subject's stomach.

[0023] With this configuration, the endoscope insertion aid of the present invention has a curved shape of the tubular body that fits comfortably inside the human stomach, and the position of the opening on the inside of the curved shape of the tubular body is set to match the position of the duodenal papilla, starting from the position where the opening fits into the stomach.In the process of placing the aid over the insertion part of the endoscope and guiding it to the back of the subject's duodenum, the rigidity of the endoscope is also used to change the position of the duodenum, and the opening can be naturally positioned to face the duodenal papilla. Effect of the Invention

[0024] According to the present invention, it is possible to provide an endoscope insertion aid that has a simple configuration and can be reliably and easily positioned so that its opening faces the duodenal papilla. [Brief description of the drawings]

[0025] [Figure 1] 1 is a perspective view of an overtube for inserting a thin endoscope according to an embodiment of the present invention; [Diagram 2] 2 is a perspective view showing a state in which the overtube for inserting a thin-diameter endoscope in FIG. 1 is placed upside down. FIG. [Diagram 3] 1 is a plan view showing an overtube for inserting a thin endoscope according to an embodiment of the present invention placed horizontally. FIG. [Figure 4] 4 is a cross-sectional view taken along line AA of the overtube for inserting a thin endoscope in FIG. 3. [Diagram 5] 4 is a cross-sectional view taken along line BB of the overtube for inserting a thin endoscope in FIG. 3. [Figure 6] 5A and 5B are side views of an overtube for inserting a thin-diameter endoscope according to one embodiment of the present invention, where FIG. 5A is a view seen from the direction of an arrow C, and FIG. [Figure 7] 4 is a front view of the overtube for inserting a thin endoscope in FIG. 3 as seen from the direction of the arrow E, where (a) shows a state in which the balloon is contracted, and (b) shows a state in which the balloon is inflated. [Figure 8] 1 is a side view showing a configuration of a grip of an overtube for inserting a thin-diameter endoscope according to an embodiment of the present invention. FIG. [Figure 9] 1A to 1C are conceptual diagrams showing a procedure for inserting a thin endoscope into a lumen of a subject using an overtube for inserting a thin endoscope according to an embodiment of the present invention. [Figure 10] 1A and 1B are conceptual diagrams showing a procedure for inserting a thin endoscope using an overtube for inserting a thin endoscope according to one embodiment of the present invention beyond the duodenum of a subject, in which (a) shows a procedure for inserting the thin endoscope deep into the duodenum, and (b) shows a procedure for inserting the thin endoscope from the duodenal papilla into the bile duct. [Figure 11] FIG. 11 is a conceptual diagram showing a cross section taken along line FF in FIG. [Figure 12] 11 is an enlarged side view showing a state in which the balloon of the overtube for inserting a thin-diameter endoscope in FIG. 10(b) is inflated. FIG. [Figure 13] FIG. 1 is a perspective view showing the configuration of different types of endoscopes, where (a) shows an endoscope with a specially thinned cholangioscope inserted therein, and (b) shows a thin-diameter endoscope. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0027] 1 to 8 show an overtube 1 for inserting a thin-diameter endoscope according to one embodiment of the present invention.

[0028] This overtube for inserting a thin endoscope (hereinafter simply referred to as the overtube) 1 corresponds to the endoscope insertion aid of the present invention, and is used to guide the insertion portion 21 of a thin endoscope 20 (see Figure 13(b)) into the lumen of a subject.

[0029] In this embodiment, the overtube 1 has a side hole (side wall opening 12: see Figure 3) provided in the side wall, and by covering the insertion portion 21 of the thin-diameter endoscope 20 and inserting it, for example, from the oral cavity of the subject, deep into the duodenum 51, the side hole of the overtube 1 is naturally positioned to face the duodenal papilla 51a (see Figures 9 and 10).

[0030] To achieve this, in this embodiment, it is assumed that the tube body (cylindrical body 10: see Figure 3) of the overtube 1 is flexible, and the shape of the tube body is curved so that it fits well within the human stomach 50 (see Figures 9 and 10) and assumes a fitting posture that is close to a fixed posture, and the position of the side hole and the inclination angle θ1 with respect to the curved portion of the tube body are set to match the position of the duodenal papilla 51a, which begins from the fitting position of the tube body within the human stomach 50 in the above-mentioned fitting posture.

[0031] First, the configuration of the overtube 1 will be described.

[0032] As shown in FIGS. 1 to 3, an overtube 1 according to this embodiment includes a tubular body 10 through which a thin-diameter endoscope 20 can be inserted, and a grip 11 for operating this tubular body 10.

[0033] The cylindrical body 10 is formed, for example, by molding a flexible material into a tube shape (tubular shape) in which a hole through which the thin endoscope 20 can be inserted extends in the axial direction, and a lubricating coat is applied to the outer circumferential surface and the inner circumferential surface of the hole. As shown in FIG. 4, the cylindrical body 10 has an outer diameter OD1 of, for example, 10 mm and an inner diameter ID1 of, for example, 8 mm. Note that the inner diameter ID1 is preferably 5 mm or more, and more preferably 7 mm or more, in order to insert the thin endoscope 20 into the cylindrical body 10. Furthermore, the outer diameter OD1 is preferably 20 mm or less, and more preferably 15 mm or less, in order to insert the cylindrical body 10 into the duodenum. Examples of materials for the cylindrical body 10 include polymeric materials such as polyamide resin, polyamide-based elastomer, polyurethane, silicone, polyether ether ketone, polyether imide, polyethylene, and polyvinyl chloride (PVC). It is desirable for the material for the cylindrical body 10 to be transparent, but this is not limited thereto.

[0034] The cylindrical body 10 maintains a curved shape that is curved (draws a curved line) at a predetermined curvature in a natural state where no force from the user (practitioner) is applied, for example, when placed on a horizontal plane (corresponding to the specified plane in the present invention) defined as the XY plane in FIG. 3. In particular, FIG. 3 illustrates a cylindrical body 10 having a curved shape that is curved at a constant curvature and has a shape (arc shape) that corresponds to a substantially circular arc with a diameter D1. Here, the diameter D1 of the cylindrical body 10 is not particularly limited, but is preferably set in the range of 250 mm to 450 mm, for example, 400 mm. In addition, when the diameter D1=400 mm, the total length of the cylindrical body 10 is preferably shorter than, for example, 1256 (π×D1=1256) mm, and may be, for example, about 1000 mm. In this way, the cylindrical body 10 has flexibility and has a curved shape that maintains a predetermined curvature when placed on a horizontal surface. In the example of FIG. 3, the curved shape of the cylindrical body 10 is defined as a shape that describes a circular arc with a radius of curvature of (D1) / 2 from the center C of the above-mentioned substantially circular circle.

[0035] The cylindrical body 10 is open at both ends, with the side where the grip 11 is provided being the rear end side and the opposite side being the tip side, forming a rear end opening 10a and a tip opening 10b (see Figs. 1 to 3), respectively. The rear end opening 10a functions as an insertion port into which the insertion part 21 of the thin endoscope 20 is inserted, and the tip opening 10b functions as a window for securing an imaging area for the thin endoscope 20 and as an opening through which the insertion part 21 of the thin endoscope 20 protrudes.

[0036] The grip 11 is formed by molding a resin material into a cylindrical shape as shown in FIG. 8, and is configured by inserting the tubular body 10 in a fixed state in the central axial direction of the cylindrical shape. The grip 11 shown in FIG. 8 is a drum shape in which the outer circumference gradually decreases from both ends in the axial direction toward the center, but other shapes are also possible. The grip 11 illustrated in FIG. 8 has a length L1 between both ends of, for example, 40 mm, and a diameter D2 of the end faces on both ends of, for example, 32 mm. The side surface of the grip 11 connecting the both ends forms a surface along an arc with a curvature radius R1 in the axial direction. As an example, the curvature radius R1 is, for example, 40 mm, and the length L2 of the side surface in this case is determined by the curvature radius R1.

[0037] In the overtube 1, a side wall opening 12 for leading out a tip portion 22 of an insertion portion 21 of a thin-diameter endoscope 20 inserted therethrough is provided in a side wall on the tip side of the cylindrical body 10. The side wall opening 12 corresponds to the opening in the present invention.

[0038] 1 to 3, 5 and 6, the side wall opening 12 is formed on the inner side surface of the curved shape on the axial tip side of the cylindrical body 10. More specifically, the side wall opening 12 is formed along the axial direction of the cylindrical body 10 on the side wall on the side of the center C (see FIG. 3) that defines the curved shape of the cylindrical body 10. Also, as shown in FIG. 5, for example, the side wall opening 12 opens in a direction inclined from 0° to 90° with respect to the plane (XY plane: horizontal plane) on which the overtube 1 in FIG. 3 is placed.

[0039] In particular, in Fig. 5, the side wall opening 12 is provided at a position having a predetermined inclination angle θ1 in the circumferential direction of the cylindrical body 10 with respect to the horizontal plane on the surface of the cylindrical body 10. In the cylindrical body 10 illustrated in Fig. 5, the side wall opening 12 is structured to open facing obliquely downward with an inclination angle θ1 = 50° with respect to the horizontal plane. When the overtube 1 having the cylindrical body 10 with the side wall opening 12 facing obliquely downward with respect to the horizontal plane is used upside down (see Fig. 2, for example), it goes without saying that the side wall opening 12 faces obliquely upward with respect to the horizontal plane.

[0040] As shown in Figs. 6(a) and (b), the side wall opening 12 of the cylindrical body 10 has a length L5 in the axial direction of the cylindrical body 10 of, for example, 15 mm, a depth L6 from the outer circumferential surface of the cylindrical body 10 of, for example, 5 mm, and a width L7 (length in a direction perpendicular to the axial direction of the cylindrical body 10) of, for example, 8 mm. In this way, when the diameter OD1 (=10 mm) of the outer periphery of the cylindrical body 10 is a, the side wall opening 12 of the overtube 1 has a length 1.5 times the diameter a in the axial direction of the cylindrical body 10 and a depth 1 / 2 times the diameter a from the outer periphery. The shape of the side wall opening 12 shown in Figs. 6(a) and (b) is merely an example, and it is preferable that the side wall opening 12 in the overtube 1 according to this embodiment has a length of 1.0a to 2.0a in the axial direction of the cylindrical body 10 and a depth of 0.3a to 0.7a from the outer periphery of the cylindrical body 10.

[0041] The shape of the side wall opening 12 shown in Figures 5 and 6 is based on the premise that the curved shape of the tubular body 10 is formed into a shape that easily fits into the shape of the essential part of the inner wall of the human stomach 50, and the inclination angle θ1 with respect to the above-mentioned plane in the circumferential direction of the tubular body 10 is set to match the position of the duodenal papilla 51a (see Figures 9 and 10), which begins at the position where the tubular body 10 fits into the human stomach 50.

[0042] As shown in Figs. 1 to 3, 6 and 7, the cylindrical body 10 is provided with a balloon 13 on the circumferential surface further to the tip side of the side wall opening 12. The balloon 13 is wound and fixed around the cylindrical body 10 in the circumferential direction, leaving a partial section, and is configured to be selectively inflatable and deflated outward in the circumferential direction on the circumferential surface opposite the partial section. That is, the balloon 13 constitutes an eccentric expansion balloon whose expansion is restricted on the circumferential surface of the cylindrical body 10 opposite the side where the side wall opening 12 is formed. Such an eccentric expansion balloon may be, for example, structured such that the region corresponding to the above-mentioned partial section of the balloon 13 provided over the entire circumferential surface of the cylindrical body 10 is suppressed so as not to be inflated, or structured such that the film thickness of the balloon 13 is thicker in the region corresponding to the above-mentioned partial section than in other regions, so as not to be inflated.

[0043] For the balloon 13, the angle θ2 corresponding to the circumferential length of the region in the cylindrical body 10 where the expansion is restricted can be, for example, θ2=50° as shown in Fig. 7. The expansion of this balloon 13 is restricted at the circumferential position of the angle θ2 in the cylindrical body 10, and as shown in Fig. 7(b), only on the opposite circumferential side, the balloon 13 expands toward the outside of the cylindrical body 10 at an angle of, for example, 25° ((θ2) / 2) diagonally downward with respect to the above-mentioned horizontal plane. Here, the balloon 13 expanding toward the diagonal downward angle of 25° covers the entire region in the width direction of the side wall opening 12 provided at an inclination angle θ1 with respect to the above-mentioned horizontal plane with respect to the circumferential region of the cylindrical body 10.

[0044] The material of the balloon 13 is not particularly limited, but is preferably a material having a certain degree of flexibility, and examples of materials that can be used include polyethylene, polyethylene terephthalate, polypropylene, copolymers of ethylene and other α-olefins such as ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, polyvinyl chloride (PVC), cross-linked ethylene-vinyl acetate copolymers, polyurethane, polyamide, polyamide elastomers, polyimides, polyimide elastomers, silicone rubber, natural rubber, and isoprene rubber.

[0045] The balloon 13 can be manufactured by using the above-mentioned materials and applying various conventionally known molding methods as balloon molding methods, such as blow molding. The thickness of the balloon 13 can be, for example, about 0.01 to 0.50 mm, but is not particularly limited. As an example of the size of the balloon 13, as shown in FIG. 6, the outer diameter D3 when deflated can be, for example, 14 mm, and the length L3 in the axial direction can be, for example, 20 mm.

[0046] The overtube 1 also has a fluid passage 14 formed on the surface of the cylindrical body 10 along the axial direction, for feeding a medium (e.g., liquid or gas) for inflating and deflating the balloon 13. As shown in Fig. 4, the fluid passage 14 is formed with an outer diameter OD2 of, for example, 2 mm and an inner diameter ID2 of, for example, 1 mm.

[0047] As shown in Figs. 1 to 3, a stopcock 15 for opening and closing the fluid passage 14 is provided at the rear end side of the cylindrical body 10. The stopcock 15 is connected to a fluid storage device (not shown) via a fluid supply / suction device. By opening / closing the stopcock 15, the overtube 1 can supply fluid from the fluid storage device through the fluid passage 14 by the fluid supply / suction device to inflate the balloon 13 (see Fig. 7(b)), or can return the fluid in the fluid passage 14 to the fluid storage device by the fluid supply / suction device to contract the balloon 13 (fold it to a non-inflated state as shown in Fig. 7(a)). When inflated by the supply of the fluid, the balloon 13 serves to receive the tip 22 of the insertion part 21 of the thin endoscope 20 led out from the side wall opening 12 and change its direction (see Fig. 12). The fluid passage 14 and the stopcock 15 correspond to the medium flow path and the on-off valve of the present invention, respectively.

[0048] Next, an endoscope using the overtube 1 as an insertion aid will be described. The overtube 1 is used, for example, to guide a thin endoscope 20 shown in Fig. 13(b) into a lumen (common bile duct 53) of a subject. The thin endoscope 20 is an endoscope with a thinner outer diameter of the insertion portion compared to the most common endoscope, such as the endoscope 30 (see Fig. 13(a)), and the thin endoscope 20 used has an outer diameter of the insertion portion preferably in the range of 4 to 8 mm, more preferably in the range of 5 to 7 mm.

[0049] As shown in Fig. 13(b), the thin endoscope 20 has an observation optical system 23, an illumination optical system 24, an air / water nozzle 25, and a forceps port 26 on a distal end surface 22a of the distal end 22 of the insertion section 21. In the thin endoscope 20, the insertion section 21 has a required length suitable for endoscopic examination and treatment, and a hand operation section (not shown) is provided on the rear end side (opposite the distal end 22). Between the distal end surface 22a and the hand operation section, the insertion section 21 accommodates a mechanism for acquiring an image in front through the observation optical system 23 by operating various operation buttons on the hand operation section, a mechanism for driving the illumination optical system 24 to illuminate the front, a mechanism for feeding gas and water through the air / water nozzle 25, a forceps port 26 for inserting a treatment tool such as forceps, and the like.

[0050] Next, a method of operating the overtube 1 according to this embodiment will be described with reference to Figures 9 to 12. Here, a method of operating the overtube 1 with its insertion part 21 placed thereon, that is, the overtube 1 with the insertion part 21 inserted into a hole extending in the axial direction of the tubular body 10, will be described when using a commercially available transnasal endoscope as the thin-diameter endoscope 20, and guiding the overtube 1 into the bile duct (common bile duct 53) of a subject.

[0051] In endoscopic examination and treatment of the bile duct using the thin endoscope 20, the practitioner (doctor) first covers the insertion section 21 of the thin endoscope 20 with the overtube 1, and in this state inserts the overtube 1 together with the insertion section 21 from the oral cavity of the subject. The subject may be in either a prone position or a left lateral position. The operation of covering the overtube 1 on the insertion section 21 is performed by pushing the insertion section 21 inserted from the rear end opening 10a of the cylindrical body 10 until its tip reaches a position near the tip opening 10b, or until the tip of the insertion section 21 protrudes from the tip opening 10b.

[0052] Next, the practitioner performs an operation to push the overtube 1 forward to a position immediately before the entrance of the duodenum 51 in the stomach 50 of the subject, as shown in Fig. 9. This operation can be performed while checking the forwarding position while displaying on a monitor an image captured through the distal end opening 10b of the overtube 1 via the observation optical system 23. At this time, the balloon 13 provided on the distal end side of the cylindrical body 10 of the overtube 1 is in a deflated state (see Fig. 7(a)).

[0053] The practitioner further operates the overtube 1 so as to push it deeper into the duodenum 51. During this operation, the practitioner pushes it forward while confirming the insertion position by displaying the captured image obtained by the observation optical system 23 on the monitor, and at the same time, while checking the X-ray fluoroscopic image, pushes the side wall opening 12 of the overtube 1 deeper into the duodenum 51 than the duodenal papilla 51a, and then returns the thin endoscope 20 to the position of the side wall opening 12 of the overtube 1 or further to the rear end side, and confirms the position of the duodenal papilla 51a from the captured image obtained there.

[0054] The practitioner performs an operation such as twisting the thin endoscope 20 and / or the overtube 1 to move the duodenum 51 from the position shown in FIG. 9 to the position shown in FIG. 10(a).

[0055] By changing the position of the duodenum 51 in this manner, when the thin endoscope 20 is inserted into the bile duct (toward the liver 52), the pushing force exerted when pushing in the proximal portion of the thin endoscope 20 is more easily transmitted to the tip side.

[0056] The overtube 1 according to this embodiment is pushed deep into the duodenum 51 of the subject, and when the duodenum 51 assumes the posture shown in Fig. 10(a), the side wall opening 12 of the tubular body 10 is disposed at a position facing the duodenal papilla 51a. That is, in this embodiment, the tubular body 10 is formed into a curved shape (see Fig. 9) that fits well with the shape of the inner wall of the stomach 50 of the subject, and the inclination angle θ1 (see Fig. 5) of the side wall opening 12 on the inside of the curved shape of the tubular body 10 is set so that the side wall opening 12 faces the position of the duodenal papilla 51a determined by the posture change of the duodenum 51.

[0057] Figure 11 conceptually shows the cross section taken along line FF in Figure 10(a), with the side wall opening 12 of the tubular body 10 of the overtube 1 positioned facing the duodenal papilla 51a of the subject's duodenum 51.

[0058] With the overtube 1 inserted until the side wall opening 12 of the tubular body 10 is positioned opposite the duodenal papilla 51a (see Figure 10(a)), the practitioner guides the insertion portion 21 of the thin-diameter endoscope 20 forward from the side wall opening 12 of the tubular body 10 and inserts it further into the common bile duct 53 from the duodenal papilla 51a.

[0059] Prior to this operation, the practitioner pulls back the insertion section 21 of the thin endoscope 20 from the inserted state of the overtube 1 shown in FIG. 10(a) until the tip surface 22a comes to the position of the side wall opening 12 of the cylindrical body 10.

[0060] Next, the practitioner confirms that the side wall opening 12 is in a position facing the duodenal papilla 51a while monitoring the captured image obtained by the observation optical system 23 at that position, and then leads out the tip 22 of the insertion section 21 of the thin endoscope 20. The lead-out of the tip 22 of the insertion section 21 can be performed, for example, by the practitioner operating a hand-held operation section (not shown) of the thin endoscope 20 to bend the tip 22 of the insertion section 21.

[0061] 10(b), the practitioner performs an operation to inflate the balloon 13 provided at the tip of the cylindrical body 10 of the overtube 1. At that time, the practitioner opens the stopcock 15, thereby causing the fluid supply / suction device to supply fluid from the fluid storage device through the fluid passage 14, thereby inflating the balloon 13.

[0062] Fig. 12 is an enlarged side view showing the inflated state of the balloon 13 of the overtube 1 in Fig. 10(b). As shown in Fig. 12, the tip 22 of the insertion part 21 of the thin endoscope 20 is led out from the side wall opening 12 of the cylindrical body 10, and the balloon 13 is inflated. In this state, the practitioner further pushes the thin endoscope 20 forward (in the direction of the arrow).

[0063] At that time, the tip 22 of the insertion section 21 of the thin endoscope 20 hits the inflated balloon 13 and is pushed back so as to face the duodenal papilla 51a. This allows the practitioner to continue the operation of further pushing the insertion section 21 in the direction of the arrow, thereby making it possible to insert the tip 22 of the insertion section 21 into the duodenal papilla 51a and further into the common bile duct 53, as shown in Fig. 10(b).

[0064] With the tip 22 of the insertion section 21 inserted into the common bile duct 53, the practitioner can perform an endoscopic examination of the bile duct by illuminating the inside of the common bile duct 53 with the illumination optical system 24 and checking the internal condition of the common bile duct 53 while monitoring the captured image obtained by the observation optical system 23. Furthermore, endoscopic treatment of the common bile duct 53 can be performed by feeding gas or liquid from the air / water nozzle 25 as necessary and leading a treatment tool such as forceps from the forceps port 26.

[0065] Next, the operation will be described.

[0066] In the overtube 1 according to the present embodiment, the shape of the tubular body 10 is formed into a curved shape that fits well with, for example, the curve of the inner wall of the human stomach 50. The overtube 1 fitting well with the subject's stomach 50 means that the overtube 1 can be easily maintained in a curved shape that follows the inner wall of the stomach 50 when inserted into the stomach 50, regardless of the posture at the start of insertion, that is, the overtube 1 can be easily maintained in a constant posture or a posture close to that in the stomach 50.

[0067] In the overtube 1 according to this embodiment, the position of the sidewall opening 12 provided inside the curved shape of the tubular body 10 and the inclination angle θ1 are set to match the position of the duodenal papilla 51a starting from the position where the tubular body 10 is placed in the human stomach 50 in the above-mentioned fixed posture (or a posture close thereto). As a result, in the overtube 1 according to this embodiment, when used as an auxiliary tool for inserting the thin endoscope 20 into the lumen of a subject, the curved shape of the tubular body 10 allows the thin endoscope 20 to be well placed on the inner wall of the subject's stomach 50, and when the thin endoscope 20 is further pushed into the duodenum 51, the sidewall opening 12 naturally faces the duodenal papilla 51a. Therefore, it becomes possible to easily insert the insertion part 21 of the thin endoscope 20 from the duodenal papilla 51a into the common bile duct 53.

[0068] In the above embodiment, an example of endoscopic examination and treatment is given in which the insertion section 21 of the thin endoscope 20 is inserted into the common bile duct 53 of a subject, but the overtube 1 according to this embodiment can be similarly used in cases where it is inserted into the common hepatic duct or pancreatic duct. This overtube 1 can be applied to general thin endoscopes 20, such as those that can be inserted from the mouth of a subject, in addition to the above-mentioned transnasal endoscope.

[0069] In addition, in the above-described embodiment, the shapes and dimensions of the tubular body 10, the grip 11, the side wall opening 12, the balloon 13, etc. in the overtube 1 are specified, but this is merely an example, and it goes without saying that various other shapes and dimensions can be adopted.

[0070] As described above, the overtube 1 in this embodiment is an endoscope insertion aid for guiding the insertion portion 21 of a thin-diameter endoscope 20 into a subject's lumen, and is configured to have a flexible, curved tubular body 10 that maintains a predetermined curvature when placed on a specified plane and has a hole extending in the axial direction through which the insertion portion 21 can be inserted, and a side wall opening 12 formed in the side wall on the center C side that determines the curved shape of the axial tip side of the tubular body 10, and through which the tip portion 22 of the insertion portion 21 can be led out.

[0071] The overtube 1 in this embodiment can be realized by a simple structure in which the cylindrical body 10 is formed into a curved shape using a flexible material, and a side wall opening 12 is provided in the side wall on the side of the center C that defines the curved shape.

[0072] Furthermore, in this overtube 1, the curved shape of the tubular body 10 is designed to fit well within the human stomach 50 and to have a nearly constant fitting posture, and the position of the side wall opening 12 is set taking into consideration the position (fitting position) of the duodenal papilla 51a relative to the tubular body 10 in the above-mentioned fitting posture of the human. This makes it easy to position the side wall opening 12 of the tubular body 10 in a position facing the duodenal papilla 51a when it is placed over the insertion portion 21 of the thin-diameter endoscope 20 and guided to the back of the duodenum 51.

[0073] Moreover, in the overtube 1 according to this embodiment, the side wall opening 12 is configured to be provided at a position having a predetermined inclination angle θ1 in the circumferential direction of the cylindrical body 10 with respect to the above-mentioned specified plane of the surface of the cylindrical body 10.

[0074] With this configuration, the overtube 1 according to this embodiment can be positioned so that the side wall opening 12 of the tubular body 10 naturally and reliably faces the duodenal papilla 51a in the process of covering the insertion part 21 of the thin endoscope 20 and guiding it to the back of the subject's duodenum 51 by setting the inclination angle θ1 of the side wall opening 12 in the circumferential direction of the tubular body 10 in accordance with the position of the duodenal papilla 51a starting from the fitting position of the tubular body 10 in the stomach 50. In addition, after that, the tip part 22 of the insertion part 21 can be led out of the side wall opening 12 and easily inserted into the duodenal papilla 51a, and from there the insertion part 21 can be easily guided into the common bile duct 53.

[0075] Moreover, in the overtube 1 of this embodiment, the side wall opening 12 has a length of 1.0a to 2.0a in the axial direction of the cylindrical body 10, and a depth of 0.3a to 0.7a from the outer periphery of the cylindrical body 10, when the diameter of the outer periphery of the cylindrical body 10 is a.

[0076] With this configuration, the overtube 1 in this embodiment has a side wall opening 12 that opens to a size larger than the size of the tubular body 10, so that the operation of guiding the insertion portion 21 of the thin-diameter endoscope 20 and the operation of pushing it forward can be performed reliably and easily.

[0077] Moreover, the overtube 1 according to this embodiment has an inflatable and deflateable balloon 13 provided along the circumferential surface of the cylindrical body 10 on the tip side of the side wall opening 12.

[0078] With this configuration, the overtube 1 of this embodiment can easily guide the tip 22 of the insertion portion 21 of the thin endoscope 20 extended from the side wall opening 12 to the duodenal papilla 51a by abutting the tip 22 of the insertion portion 21 against the inflated balloon 13 and changing its direction.

[0079] Moreover, in the overtube 1 of this embodiment, the balloon 13 has a configuration in which expansion is restricted on the peripheral surface of the tubular body 10 opposite the side on which the side wall opening 12 is formed.

[0080] The overtube 1 in this embodiment has an eccentric expansion balloon structure in which the balloon 13 expands only toward the side of the tubular body 10 on which the side wall opening 12 is formed. As a result, by inflating the balloon 13 with the side wall opening 12 facing the duodenal papilla 51a, it becomes easy to obtain the space between the side wall opening 12 and the duodenal papilla 51a required to curve the tip 22 of the insertion portion 21 of the thin endoscope 20 toward the duodenal papilla 51a, and the insertion portion 21 of the thin endoscope 20 can be more easily guided to the duodenal papilla 51a.

[0081] In addition, the overtube 1 in this embodiment is further configured to have a fluid passage 14 formed along the axial direction on the surface of the cylindrical body 10, for supplying a fluid for inflating and deflating the balloon 13, and a stopcock 15 connected to the fluid passage 14.

[0082] With this configuration, the overtube 1 of this embodiment allows the practitioner to easily inflate the balloon 13 in accordance with the timing at which the insertion portion 21 of the thin-diameter endoscope 20 is led out of the side wall opening 12 by operating the stopcock 15 at hand.

[0083] Moreover, the overtube 1 in this embodiment is used to cover the insertion portion 21 of the thin-diameter endoscope 20 and guide the insertion portion 21 through the duodenal papilla 51a of the subject to the common bile duct 53, and the tubular body 10 is formed into a curved shape that can easily fit into a key portion of the inner wall of the human stomach 50, and the side wall opening 12 is configured such that the circumferential inclination angle θ1 of the tubular body 10 is set so that the side wall opening 12 is positioned to face the duodenal papilla 51a when the subject's duodenum 51 is changed in position and the tubular body 10 is fitted within the subject's stomach 50.

[0084] With this configuration, the overtube 1 of this embodiment has a curved shape of the tubular body 10 that fits well inside the human stomach 50, and the position of the side wall opening 12 on the inside of the curved shape of the tubular body 10 is set to match the position of the duodenal papilla 51a, which starts from the fitting position.In the process of covering the insertion portion 21 of the thin endoscope 20 and guiding it to the back of the subject's duodenum 51, the stiffness of the thin endoscope 20 is also utilized to change the position of the duodenum 51, and the side wall opening 12 can be naturally positioned to face the duodenal papilla 51a.

[0085] In addition, the overtube 1 according to this embodiment can be easily operated by the practitioner and can be positioned so that the side wall opening 12 faces reliably toward the duodenal papilla 51a, thereby making the procedure less difficult.

[0086] Furthermore, this overtube 1 allows the thin endoscope 20 to be easily inserted and removed repeatedly from the common bile duct 53, and is excellent in terms of ease of repeated insertion and removal from the common bile duct.

[0087] Furthermore, in this overtube 1, the inner diameter of the tubular body 10 can be made relatively large and the size of the side wall opening 12 can be set large, compared to when a specially thinned cholangioscope 31 with an outer diameter of the insertion portion of about 3.5 mm is used. This makes it suitable for guiding a thin endoscope 20 having a relatively large diameter forceps port 26.

[0088] Furthermore, this overtube 1 can easily guide the thin-diameter endoscope 20, which is equipped with a camera with higher resolution than the specially thin-diameter cholangioscope 31, into the common bile duct 53, thereby improving the image resolution of the captured image obtained through the observation optical system 23.

[0089] In addition, since this overtube 1 makes it possible to guide a thin-diameter endoscope 20, which is widely used, into the common bile duct 53, costs can be reduced compared to when a specially thin-diameter cholangioscope 31 is used.

[0090] As described above, the endoscope insertion aid of the present invention has a simple configuration and provides the advantageous effect of enabling the opening to be reliably and easily positioned to face the duodenal papilla, and is useful as a general endoscope insertion aid used to guide a thin-diameter endoscope. [Explanation of symbols]

[0091] 1. Overtube for inserting thin endoscope (endoscope insertion aid) 10 Cylindrical body 12 Side wall opening (opening) 13. Balloon 14 Fluid passage (medium flow path) 15 Stopcock (on-off valve) 20 Thin endoscope (endoscope) 21 Insertion section 22 Tip of insertion part 50 Stomach 51 Duodenum 51a Duodenal papilla 52 Liver 53 Common bile duct (bile duct, lumen)

Claims

1. An endoscope insertion aid for guiding an insertion portion of an endoscope into a lumen of a subject, comprising: A curved cylindrical body having flexibility and a predetermined curvature when placed on a specified plane, the curved cylindrical body having a hole extending in the axial direction through which the insertion portion can be inserted, and the curved cylindrical body having a curved curvature when placed on a specified plane, an opening formed in a side wall on a center side that defines the curved shape on the axial tip side of the cylindrical body, the opening leading out a tip end of the insertion portion; a balloon provided along a peripheral surface of the cylindrical body on a distal end side of the opening and capable of expanding and contracting; having the cylindrical body is placed over the insertion portion of the endoscope and inserted together with the endoscope from the oral cavity of the subject, and after being pushed forward to the duodenum of the subject, the posture of the duodenum is changed, the tip portion of the insertion portion of the endoscope is led out from the opening, and the tip portion, which hits the inflated balloon and is pushed back so as to face the duodenal papilla of the subject, is guided to the bile duct via the duodenal papilla of the subject, The cylindrical body is formed such that the curved shape is easily fitted into a main part of the inner wall of a human stomach, the opening has an inclination angle in the circumferential direction of the cylindrical body set so that the opening faces the duodenal papilla when the subject's duodenum is changed in position and the cylindrical body is placed in the stomach of the subject, and has a depth of 0.3a to 0.7a from the outer periphery of the cylindrical body, where a is the diameter of the outer periphery of the cylindrical body; The outer diameter of the cylindrical body is 15 mm or less, An endoscope insertion aid, characterized in that the curved shape of the cylindrical body is an arc shape having a diameter of 250 mm to 450 mm.

2. 2. The endoscope insertion aid according to claim 1, wherein the opening is provided at a position having an inclination angle of 0° to 90° in the circumferential direction of the cylindrical body with respect to the specified plane on the surface of the cylindrical body.

3. 3. An endoscope insertion aid according to claim 1, wherein the opening has a length of 1.0a to 2.0a in the axial direction of the cylindrical body.

4. 4. An endoscope insertion aid according to claim 1, wherein the balloon has a configuration in which inflation is restricted at a peripheral surface of the cylindrical body opposite to the side on which the opening is formed.

5. 5. The endoscope insertion aid according to claim 1, further comprising: a medium flow path formed on a surface of the cylindrical body along the axial direction, for supplying a medium for inflating and deflating the balloon; and an opening and closing valve for the medium flow path.

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