JP3969095B2 - Endoscope hood - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hood connected to an insertion portion of an endoscope, and more particularly, to an inner portion provided with a guide portion for guiding a treatment instrument inserted in a treatment instrument insertion passage of the endoscope in a predetermined direction. The present invention relates to an endoscope hood.
[0002]
[Prior art]
The hood is attached to the leading end of the insertion portion of the endoscope, such as those JP shown in JP 2001 -149313 are known in the art. This hood is fitted to the distal end of the insertion portion and protrudes forward by a predetermined length from the distal end. By narrowing the protruding portion toward the distal end side, the distal end opening diameter is inserted. It is smaller than the outer diameter of the part. Then, the distal end of the hood is brought into contact with the inner wall of the body cavity, and the inner wall of the body cavity is preferably sucked with a negative pressure inside the hood, and the puncture treatment instrument is led out from the treatment instrument insertion path and punctured toward the vein. Yes. The treatment instrument insertion path is provided at a position deviated from the center position of the insertion portion, and the hood does not interfere with the extension line direction of the treatment instrument insertion path, that is, the treatment instrument insertion path of the insertion section. The side on which the passage is located extends straight, and the opposite side is inclined forward. As a result, the puncture treatment instrument is guided straight forward from the treatment instrument insertion passage so that it can puncture the inner wall of the body cavity.
[0003]
[Problems to be solved by the invention]
By the way, since the hood protrudes from the distal end surface of the insertion portion of the endoscope, the distal end surface of the insertion portion is separated from the inner wall of the body cavity when the distal end portion of the hood is in contact with the inner wall of the body cavity. In this state, when the treatment instrument is led out from the treatment instrument insertion path, the treatment instrument is not guided from the exit of the treatment instrument insertion path to the inner wall of the body cavity. In the conventional technique described above, in the case of a puncture treatment instrument, in order to increase the thrust for puncturing into a body cavity, the rigidity in the bending direction must be high. Even if no special guide is provided between the treatment instrument insertion path and the inner wall of the body cavity, the puncture operation is not hindered.
[0004]
However, since the insertion portion bends along the insertion path into the body cavity, it is desirable that the treatment instrument inserted into the treatment instrument insertion path is as flexible as possible in the bending direction. For this reason, except for a treatment instrument that requires a large thrust at the time of puncture, a treatment instrument that is flexible, in other words, has a low back is used. Accordingly, there is a problem that when such a low-back treatment tool is led out from the treatment tool insertion path and sniped on a lesioned part or the like in a free state, its operability is not always good.
[0005]
The present invention has been made in view of the above points, and an object of the present invention is to provide an endoscope that can reliably guide a treatment instrument led out from a treatment instrument insertion path to a site to be treated. The purpose is to provide food.
[0006]
[Means for Solving the Problems]
In order to achieve the above-described object, the present invention provides a predetermined portion from the distal end of the insertion portion to the insertion portion of the endoscope in which an illumination portion and an observation portion are formed on the distal end surface and the treatment instrument outlet portion is opened. Endoscope hood mounted so as to protrude in length, a connecting portion fixed to the outer peripheral surface of the distal end portion, and protruding from the connecting portion toward the front of the distal end surface of the insertion portion A hood main body made of a transparent member provided , and a guide portion formed on the inner surface of the hood main body, having a start end abutting on the distal end surface of the insertion portion, and having a treatment instrument passage that does not cover the treatment instrument outlet portion The treatment instrument derived from the treatment instrument deriving portion is characterized in that it is configured to be slidably guided toward the front of the center axis of the treatment instrument deriving portion by the passage. .
[0007]
In observing the body cavity inner wall from the observation part provided at the distal end of the insertion part, the distal end of the insertion part must be separated from the body cavity inner wall by a certain distance. This distance varies depending on the focal length of the objective optical system provided in the observation unit, but observation and treatment cannot be performed if at least the distal end of the insertion unit is brought into contact with the inner wall of the body cavity. By attaching the hood so that it protrudes from the distal end of the insertion section, the distal end of the hood is brought into contact with the inner wall of the body cavity, and the distance from the distal end of the insertion section to the inner wall of the body cavity is separated, and observation and necessary treatment are performed. It can be performed. If the distal end of the insertion portion and the inner wall of the body cavity are separated by the hood, when the treatment instrument is led out from the treatment instrument lead-out portion, the treatment tool becomes free between the distal end of the insertion portion and the inner wall of the body cavity. The sniping ability to etc. worsens. In particular, when the treatment instrument is flexible in the bending direction, that is, when the treatment instrument is weak, the operability is remarkably deteriorated. By providing a guide part for sliding the treatment tool on the inner surface of the hood body, even if the treatment tool is weak, such as easily bends, after it has been led out from the treatment tool lead-out part, it is surely placed in a predetermined direction. Guided and able to snip at the site to be treated. The directionality of the treatment tool by the guide unit is preferably directed to the center direction of the observation field in the observation unit provided at the distal end of the insertion unit, that is, the optical axis direction of the objective optical system attached to the observation unit.
[0008]
Since the distal end portion of the insertion portion is circular, the outer shape of the hood body can be a substantially cylindrical shape in accordance with the shape of the distal end portion. However, it can have any shape depending on the type of treatment tool used, the mode of treatment to be performed, and the like. For example, when it is necessary to orient the distal end of the treatment instrument in a direction substantially parallel to the inner wall of the body cavity, a cone shape whose diameter is reduced toward the distal end side of the outer peripheral surface of the hood body, particularly a truncated cone shape None, it may be desirable that the guide direction of the treatment tool by the guide portion be a direction substantially parallel to the outer surface of the hood body. For example, in the case of performing a treatment such as removing the mucous membrane by incising the mucous membrane from the muscle layer, it is preferable from the viewpoint of operability to direct the treatment tool led out from the guide portion to a state that is nearly parallel to the body cavity inner wall. For this reason, it is optimal that the outer surface of the hood body has a truncated cone shape. Moreover, although the hood main body is entirely composed of a transparent member, it is not always necessary to have walls around the entire circumference, and it can be partially removed as long as there is no hindrance. For example, a notch having a predetermined width can be formed in a portion where the guide portion is not provided, such as the positions on the left and right sides of the hood body. Furthermore, it is also possible to have a configuration in which a cylindrical projecting portion is continuously provided at the tip of the conical portion of the hood body. When the projecting portion is provided in this way, for example, an incision can be easily opened.
[0009]
The treatment tool must restrict movement in the guide portion other than the forward direction, that is, movement in the vertical and horizontal directions. Since the treatment tool abuts on the guide portion and advances while sliding on the surface thereof, there is no positional displacement in the vertical direction. In order not to shift in the left-right direction, a side wall portion is formed in the guide portion, and for this reason, it is possible to make a right-left direction regulating wall by configuring it with a passage whose cross-sectional shape is a concave curve shape. it can. In order to ensure that the treatment instrument can move from the treatment instrument deriving portion to the passage constituting the guide portion, the passage is positioned in front of the treatment instrument deriving portion. The shape should not be covered. Here, although the arc angle of the cross section of the guide portion is not particularly restricted, it is preferably 90 ° to 180 ° from the viewpoint of guiding the left and right side portions of the treatment instrument. For example, when guiding a high-frequency needle knife as a treatment tool, the cross-sectional shape of the passage may be an arc shape larger than the outer peripheral surface of the high-frequency needle knife. In addition, when an electrode protrudes from the tip of the tube, such as a high-frequency needle knife, this electrode is prevented from contacting the guide portion. For this reason, the guide part is formed on the inner surface of the hood body from the base end side to the middle position, and when the treatment tool is led out from the hood, the electrode at the distal end of the treatment tool is held in a non-contact state with respect to the hood body. To do.
[0010]
The connecting portion may be configured as an integral part of the hood main body, but since the hood main body is formed of a transparent member, it is desirable that the connecting portion be formed of a member separate from the connecting portion and connected to each other. The connecting portion is fitted to the insertion portion, and in order to be able to be attached to the insertion portion having a different outer diameter, the connecting portion is made of an elastic member such as rubber. The inner diameter can be enlarged or reduced by providing a plurality of slits from the side toward the hood main body.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following embodiments are described as being suitable for performing mucosal resection in a body cavity by guiding a high-frequency needle knife as a treatment tool, but the hood of the present invention is limited to this type. It goes without saying that it is not done.
[0012]
In the drawings, FIG. 1 is a cross-sectional view of a distal end portion of an endoscope and a hood attached thereto, and FIG. 2 is a left side view of FIG. In the figure, 1 is an insertion portion of an endoscope, and 10 is a hood. The distal end hard portion 1a of the insertion portion 1 of the endoscope is configured to include illumination units 2 and 2 and an observation unit 3 disposed at an intermediate position between the illumination units 2 and 2. As is well known, the illuminating unit 2 is provided with an illuminating lens facing the exit end of a light guide that transmits illumination light. The observation unit 3 includes an objective optical system 4 and a solid-state imaging device 5 disposed at the image forming position of the objective optical system 4. The illumination unit 2 and the observation unit 3 are provided on the distal end surface of the distal end hard portion 1a. Reference numeral 6 denotes a treatment instrument insertion passage through which a treatment instrument such as forceps is inserted. The treatment instrument insertion path 6 has a treatment instrument lead-out portion 7 provided at the distal end hard portion 1a, and is inserted into the treatment tool lead-out portion 7. The treatment instrument insertion pipe 8 is inserted, and a treatment instrument insertion tube 9 is connected to the proximal end portion of the treatment instrument insertion pipe 8.
[0013]
Next, as apparent from FIGS. 3 and 4, the hood 10 is composed of two members. Reference numeral 11 denotes a connecting portion, and 12 denotes a hood body. The connecting portion 11 has a cylindrical shape made of an elastic member such as rubber, and is fitted and fixed to the distal end hard portion 1 a of the insertion portion 1. And in order to be able to connect with the insertion part 1 from which an outer diameter differs, in the connection part 11 which consists of elastic members, it is only a predetermined length from the base end side in 2 to 4 places in the circumferential direction. A slit 11a is formed. Accordingly, the inner diameter of the connecting portion 11 can be expanded and reduced, and the connecting portion 11 is fixed to the distal end hard portion 1a and then fixed by taping or a band.
[0014]
The hood main body 12 is fixed to the connecting portion 11 by means such as adhesion. The hood main body 12 is formed of a transparent resin material, and the outer shape thereof is a truncated conical shape continuously reduced in diameter from the connecting portion with the connecting portion 11 toward the tip side, that is, narrower toward the tip. The opening 13 for drawing out a treatment tool is formed in the tip part. The hood main body 12 has a thickness that decreases toward the tip, and therefore has a gentler taper on the inner peripheral surface than on the outer peripheral surface. The protrusion length from the distal end surface of the distal end hard portion 1a of the hood main body 12 is a solid-state imaging device obtained via the objective optical system 4 in a state where the distal end surface of the hood main body 12 is in contact with the body cavity inner wall. 5 is set on the basis that the image captured in 5 is clear and has an image of a necessary size. That is, the protrusion length of the hood body 12 is set according to the focal length and the viewing angle of the objective optical system 4 provided in the observation unit 3.
[0015]
A guide portion 14 that guides the treatment instrument is provided on the inner surface of the hood main body 12. The guide portion 14 is a passage 16 having a circular arc cross section on the upper surface of the projection 15 whose base end side, that is, the end on the connection side to the connection portion 11 protrudes from the inner surface of the hood main body 12 by a predetermined height. The passage 16 has a length reaching the opening 13 at the tip of the hood body 12. Here, the start end portion of the passage 16, that is, the end portion of the hood main body 12 on the connection side to the connecting portion 11 is disposed at a position corresponding to the treatment instrument deriving portion 7 and does not cover the opening end of the treatment instrument deriving portion 7. Thus, it is set as the circular arc shape which has a larger curvature radius than the opening diameter of a treatment tool derivation | leading-out part. Further, if the central axis of the insertion section 1 is A1, the optical axis of the objective optical system 4 of the observation section 3 is A2, and the central axis of the treatment instrument deriving section 7 is A3, the optical axis A2 and the treatment instrument deriving section 7 It is located on the opposite side of the central axis A3 with respect to the central axis A1 of the insertion portion 1. The direction of the passage 16 is inclined by an angle θ with respect to the central axis A3 of the treatment instrument deriving unit 7 so as to be directed in the direction of the optical axis A2 of the observation unit 3, whereby the treatment tool is separated from the observation unit 3. From the position, the light travels obliquely forward toward the optical axis A2 of the observation unit 3.
[0016]
The base end surface 15 a of the protrusion 15 constituting the guide portion 14 is configured to come into contact with the distal end surface of the insertion portion 1 when the hood 10 is attached to the distal end hard portion 1 a of the insertion portion 1. Accordingly, the base end surface 15a of the projection 15 functions as a stopper that restricts the pushing end of the hood 10 into the distal end hard portion 1a. Further, the circular arc of the passage 16 formed in the protrusion 15 is approximately 180 ° or less (preferably 90 ° or more). Therefore, the right and left side portions from the bottom portion 16a of the passage 16 have a predetermined height. The rising portion 16b serves as a restriction wall that prevents the treatment tool from shifting in the left-right direction.
[0017]
The hood 10 configured as described above is fitted and inserted into the body cavity by fitting the connecting portion 11 to the distal end hard portion 1a of the insertion portion 1 and fixing it by means such as taping, for example. The hood 12 guides a treatment instrument inserted into the treatment instrument insertion path 6 in order to perform an appropriate treatment in the body cavity. In the present embodiment, the treatment tool guided by the hood 10 is the one shown in FIG. That is, this treatment instrument is a high-frequency needle knife 20. The high-frequency needle knife 20 has a thin metal lead inserted through an insulating tube 21, and the metal lead protrudes from the tip of the insulating tube 21 by a predetermined length, and this protruding portion is an electrode 22. The inner wall of the body cavity can be cut or excised by supplying a high-frequency current to the electrode 22. The high-frequency needle knife 20 is used for excision of the mucosa, and the protruding portion of the electrode 22 from the insulating tube 21 has a length protruding so as to excise only the mucous membrane and not damage the muscle layer. The output power of the high frequency current applied to the electrode 22 is adjusted.
[0018]
By the way, in general, when there is a lesion in the mucous membrane part, a grasping forceps and a high-frequency snare are used, and the lesion is surrounded by a snare wire loop in the high-frequency snare. A method of excising a lesioned part by squeezing a loop of a snare wire while flowing is adopted. However, such a procedure may cause a lesion to be left behind or damage to the muscle layer. By mounting the hood 10 on the insertion portion 1 of the endoscope and using the high-frequency needle knife 20 as a treatment instrument, the above-described disadvantages can be avoided. Therefore, a method for performing a mucosal resection procedure will be described with reference to FIG.
[0019]
As shown in FIG. 6A, it is assumed that a lesion 32 exists in the mucous membrane 31 covering the muscle layer 30 on the inner wall of the body cavity. In order to completely remove the lesioned part 32 without damaging the muscle layer 30, the syringe 33 is first inserted through the treatment instrument insertion passage 6 of the insertion part 1 as shown in FIG. Then, physiological saline 34 is injected from the syringe 33 between the muscle layer 30 and the mucous membrane 31. As a result, a predetermined range including the lesioned part 32 of the mucous membrane 31 is raised.
[0020]
Thereafter, the insertion portion 1 is once taken out from the body cavity, and the hood 10 is attached to the distal end hard portion 1a. When the hood 10 is attached to the distal end hard portion 1a, the position of the guide portion 14 provided on the hood body 12 is adjusted in the rotational direction so as to coincide with the treatment instrument lead-out portion 7. The hood body 12 is formed of a transparent member, and the position of the treatment instrument outlet 7 can be confirmed from the outside. Therefore, the position of the guide 14 and the treatment instrument outlet 7 can be easily adjusted by rotating the entire hood 10. It can be performed. In order to perform this alignment smoothly, marking or the like may be provided.
[0021]
When the insertion section 1 to which the hood 10 is attached is inserted to a position where the lesion 32 in the body cavity exists, the distal end of the hood 10 is brought into contact with the mucous membrane 31 expanded by the physiological saline 34, and the observation section 3. The observation center is opposed to the position to be excised. In this state, as shown in FIG. 6C, the high-frequency needle knife 20 is inserted into the treatment instrument insertion path 6 and protrudes from the treatment instrument lead-out portion 7. Since the entire circumference of the distal end portion of the treatment instrument deriving portion 7 is in an open state, the high-frequency needle knife 20 is smoothly led out as it is. A passage 16 in the guide portion 14 provided in the hood main body 12 faces a front position of the treatment instrument lead-out portion 7, and the passage 16 is inclined at an angle θ toward the observation portion 3. Therefore, the tip of the high-frequency needle knife 20 led out from the treatment instrument lead-out portion 7 comes into contact with the bottom portion 16a of the passage 16 so as to be pressed against it, and advances while sliding with respect to the passage 16 in the guide portion 14. In addition, since the passage 16 is formed with the rising portions 16b on the left and right, the high-frequency needle knife 20 is not displaced from side to side.
[0022]
Since the observation unit 3 is separated from the body cavity inner wall, the body cavity inner wall to be treated is clearly imaged by the solid-state imaging device 5. Further, since the passage 16 is inclined in the direction of the angle θ observation portion 3 with respect to the central axis A3 of the treatment instrument lead-out portion 7, it is guided by the passage 16 and led out from the opening 13 of the hood body 12. The electrode 22 of the knife 20 travels in the direction of the optical axis center A1 of the objective optical system 4, and includes the electrode 22 of the high-frequency needle knife 20, and the entire part derived from the treatment instrument deriving unit 7 is It will be in the state located in the visual field of the solid-state image sensor 5. FIG. As a result, the sniping ability by the high-frequency needle knife 20 is extremely good. In this state, the high frequency needle knife 20 comes into contact with the mucosa 31 by passing a high frequency current of the electrode 22, and the mucosa 31 is incised.
[0023]
And in order to peel the mucous membrane 31 from the muscle layer 30, the hood main body 12 is made to enter under the incision in the mucous membrane 31 incised with the high frequency needle knife 20. Since the hood body 12 has a truncated conical shape with a reduced diameter at the tip, the electrode 22 of the high-frequency needle knife 20 is the boundary between the muscle layer 30 and the mucosa 31 as shown in FIG. Can be clearly confirmed from the obliquely upper part of the incised portion in this way. Then, the distal end portion of the hood main body 12 enters under the mucous membrane 31 peeled off by the action of the electrode 22, and the cut mucous membrane 31 is pushed up and proceeds. As a result, the mucous membrane 31 can be accurately excised over a necessary range, the lesioned part 32 is not left, and the muscle layer 30 is not damaged.
[0024]
Here, since the hood main body 12 is made of a transparent resin, when a high-frequency current is applied to the electrode 22 of the high-frequency needle knife 20, if the electrode 22 is in contact with the hood main body 12, the hood main body 12 There is a possibility that the contact portion to the electrode may burn out. In order to avoid such a situation, as shown in FIG. 7 and FIG. 8, the guide portion 114 formed of the passage 116 formed in the protrusion 115 of the hood main body 112 provided by being connected to the connecting portion 111 of the hood 110 is provided. , It does not extend to the opening 113 at the tip, but stops at a position near the opening 113. When the treatment is performed, the electrode 22 of the high-frequency needle knife 20 always protrudes from the opening 113 of the hood main body 112, so that the electrode 22 does not contact any surface of the hood main body 112. Further, as shown in FIGS. 9 and 10, a cylindrical projecting portion 200 is continuously provided at the tip of the hood main body 212 having a truncated cone shape of the hood 210, and the passage 216 constituting the guide portion 214 is formed in this way. You may make it form to the position before the overhang | projection part 200. FIG.
[0025]
By the way, the hood main body is made of a hard member, and therefore the angle of the conical portion of the hood main body becomes steep to some extent. For this reason, the operation of peeling and lifting the mucous membrane 31 from the muscle layer 30 by the tip of the hood body becomes difficult. As shown in FIGS. 9 and 10, when a thin cylindrical projecting portion 200 is continuously provided at the tip of the hood main body 212, the projecting portion 200 easily enters between the mucous membrane 31 and the muscle layer 30. Thus, the mucous membrane 31 can be pushed and spread, and the operation of opening the incision can be smoothly performed. Further, in order to prevent the mucous membrane 31 thus opened from slipping off from the upper part of the overhanging portion 200, a ridge 201 may be formed on the outer peripheral surface of the tip of the overhanging portion 200 as shown in FIG. it can. Further, as the shape of the ridge, in addition to the one having a substantially semicircular cross section like the ridge 201 of FIG. 11, the shape of the ridge from the protruding end to the proximal end side like the ridge 202 shown in FIG. 12. When the site has an acute angle shape, the incision portion of the mucosa 31 can be held in a more stable state.
[0026]
Furthermore, the reason why the front end side of the hood main body has a truncated conical shape is to make it sink below the incised mucosa 31 when performing mucosal resection by high frequency. As shown in FIG. 14, a hood 310 having a cylindrical outer peripheral surface can be used so that the hood main body 312 connected to the connecting portion 311 extends straight. However, even in this case, the treatment tool is directed in the direction of the optical axis A1 of the observation unit 3 by inclining the passage 316 constituting the guide unit 314 provided on the inner surface of the hood main body 312.
[0027]
Furthermore, the hood body does not necessarily need a wall over the entire circumference, and it is sufficient that the wall is provided at least at a site where the guide portion is formed. Therefore, for example, as shown in FIG. 15, like the hood main body 412 of the hood 410, walls are provided only at the upper and lower portions, and the notches 400 can be formed on both the left and right sides. In this way, the observation field of view from the observation unit 3 through the hood 410 is improved by the amount of the cutout 400 provided.
[0028]
【The invention's effect】
As described above, the present invention provides a guide portion that slides and guides the treatment instrument derived from the treatment instrument insertion passage in an oblique direction with respect to the central axis of the treatment instrument lead-out portion on the inner surface of the hood body. There is an effect that the treatment tool can be reliably guided to the site to be treated.
[Brief description of the drawings]
FIG. 1 shows an embodiment of the present invention, and is a cross-sectional view of a distal end portion of an endoscope incorporating a hood.
FIG. 2 is a left side view of FIG. 1 showing a hood in phantom lines.
FIG. 3 is a longitudinal sectional view of a hood.
4 is a right side view of FIG. 3. FIG.
FIG. 5 is a configuration explanatory view showing a state in which a high-frequency needle knife as an example of a treatment instrument is inserted through a treatment instrument insertion path and led out from a hood.
FIG. 6 is an operation explanatory view showing a method of performing mucosal resection using a high-frequency needle knife.
FIG. 7 is a longitudinal sectional view of a hood showing a second embodiment of the present invention.
8 is a right side view of FIG.
FIG. 9 is a longitudinal sectional view of a hood showing a third embodiment of the present invention.
10 is a right side view of FIG. 9. FIG.
FIG. 11 is a longitudinal sectional view of a hood showing a fourth embodiment of the present invention.
FIG. 12 is a longitudinal sectional view of a hood showing a fifth embodiment of the present invention.
FIG. 13 is a longitudinal sectional view of a hood showing a sixth embodiment of the present invention.
14 is a right side view of FIG.
FIG. 15 is an external perspective view of a hood showing a seventh embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Insertion part 1a Tip hard part 3 Observation part 6 Treatment tool insertion path 7 Treatment tool derivation | leading-out part 10,110,210,310,410 Hood 11,111,311 Connection part 13,113 Opening 14,114,214,314 Guide part 15, 115 Protrusions 16, 116, 216, 316 Path 16a Bottom 16b Rising part 20 High-frequency needle knife 21 Insulating tube 22 Electrode 200 Overhang part 400 Notch

Claims (8)

An endoscope for which an illumination part and an observation part are formed on the distal end surface, and is attached to an insertion part of an endoscope having a treatment instrument lead-out part opened so as to protrude a predetermined length from the distal end of the insertion part In the hood
A connecting portion fixed to the outer peripheral surface of the tip portion;
A hood main body made of a transparent member provided so as to protrude from the connection portion toward the front of the distal end surface of the insertion portion,
It is formed on the inner surface of the hood main body , and has a guide portion having a treatment instrument passage that has a start end abutting on the distal end surface of the insertion portion and does not cover the treatment instrument outlet portion,
The endoscope having a configuration in which the treatment instrument derived from the treatment instrument deriving unit is slidably guided by the passage toward the front obliquely with respect to the central axis of the treatment instrument deriving unit. Mirror hood. The outer peripheral surface of the hood main body has a truncated conical shape that is reduced in diameter toward the tip side, and the guide section is cross-sectioned on the upper surface of the protruding portion obtained by thickening part of the inner surface of the hood main body. The endoscope hood according to claim 1, comprising a passage having a concave curved shape .   3. The endoscope hood according to claim 2, wherein notches having a predetermined width are formed at positions on both the left and right sides of the hood main body. The hood main body has a configuration in which a cylindrical projecting portion having a predetermined length is continuously provided at the tip of a truncated cone shape whose outer peripheral surface is reduced in diameter toward the tip side. The endoscope hood according to claim 2 . Claim 1 or claim 2 endoscope hood according passage formed on the guide portion is characterized in that the configuration you guide toward the treatment instrument in the observation center of the observation area.   6. The endoscope for an endoscope according to claim 5, wherein the treatment tool guided in the passage is a high-frequency needle knife, and a cross-sectional shape of the passage is an arc shape larger than an outer peripheral surface of the high-frequency needle knife. hood.   The endoscope hood according to claim 1, wherein the guide portion is configured to be provided from a proximal end side to an intermediate position on the inner surface of the hood main body.   The connecting portion is composed of an elastic member separate from the hood body, and the connecting portion is provided with a plurality of slits from the base end portion toward the connecting side to the hood body, thereby reducing the inner diameter. 2. The endoscope hood according to claim 1, wherein the hood can be expanded and contracted.

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