VEIN DISSECTING DEVICE AND METHOD
United States Patent Application
A vein harvesting device for harvesting a vein in a living body includes an elongated hollow member possessing a distal end portion and a proximal end portion, and a dissecting member at the distal end portion of the elongated hollow member and configured to dissect tissue in the body surrounding the vein during harvesting of the vein, wherein the dissecting member possessing a proximal end portion communicating with the elongated hollow member. The dissecting member possesses two side portions, with each of the side portions possessing a first end at an end of the side portion farther from the hollow member and a second end at an end of the side portion closer to the hollow member. A projection projects from the first end at each of the side portions of the dissecting member to contact the tissue in the body surrounding the vein during the harvesting of the vein.
Inventors:
Fujii, Tatsunori (Ebina-city, JP)
Application Number:
Publication Date:
04/13/2017
Filing Date:
10/13/2016
Export Citation:
TERUMO KABUSHIKI KAISHA (Tokyo, JP)
Primary Class:
International Classes:
A61B17/00; A61B17/32
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Related US Applications:
January, 2009Goren et al.June, 2006Strong et al.July, 2005Liew et al.November, 2008InabaNovember, 2009BertagnoliJanuary, 2004Fulkerson et al.February, 2005ModrovichJanuary, 2005BlackadarSeptember, 2008HorriganJanuary, 2006McadamsJune, 2008Arai et al.
Attorney, Agent or Firm:
BUCHANAN, INGERSOLL & ROONEY PC (POST OFFICE BOX 1404
ALEXANDRIA VA )
What is claimed is:
A vein harvesting device for harvesting a vein in a body, the vein harvesting device comprising: an elongated hollow member possessing a distal end portion and a
a dissecting member at the distal end portion of the elongated hollow member and configured to dissect a tissue in the body surrounding the vein during harvesting of the vein, the dissecting member possessing a proximal end portion communicating with the elo the dissecting member possessing two side portions, each side portion possessing a first end at an end of the side portion farther from the hollow member and a second end at an end of the side portion closer
and a projection projecting from the first end at each of the side portions of the dissecting member to contact the tissue in the body surrounding the vein during the harvesting of the vein.
The vein harvesting device according to claim 1, further comprising a holding portion fixed to the first end of each respective side portion and projecting away from the respective side portion so that the side portions and the holding portion together define a space in which the vein is positioned during the harvesting of the vein, each of the projections being located at a location at which the holding portion intersects the side portion.
The vein harvesting device according to claim 1, further comprising a holding portion fixed to the first end of each respective side portion and projecting away from the respective side portion so that the side portions and the holding portion together define a space in which the vein is positioned during the harvesting of the vein, each of the projections possessing a center positioned at a location at which the holding portion intersects the side portion.
The vein harvesting device according to claim 1, wherein each side portion includes a bottom surface, the projection projecting higher than the bottom surface of the respective side portion.
The vein harvesting device according to claim 1, wherein each side portion possesses a distal-most end surface, each projection projecting distally beyond the distal-most end surface of the respective side portion.
A vein harvesting device for harvesting a vein in a body, the vein harvesting device comprising: an elongated hollow member possessing a distal end portion and a
a dissecting member at the distal end portion of the elongated hollow member, the dissecting member possessing a pair of spaced apart side portions projecting away from the distal end portion of the elongated hollow member, each side portion possessing a first end at an end of the side portion farther from the hollow member portion and a second end at an end of the side portion closer
the distal end portion of each side portion possessing a groove that is open at its distal end, extends toward the proximal end portion of the side member, and terminates at a cutting member configured to cut a side branch of the vein during ha and a projection projecting from each of the side portions of the dissecting member to contact a tissue in the body surrounding the vein during the harvesting of the vein.
The vein harvesting device according to claim 6, further comprising a holding portion fixed to the first end of each respective side portion and projecting away from the respective side portion so that the side portions and the holding portion together define a space in which the vein is positioned during the harvesting of the vein, each of the projections being located at a location at which the holding portion intersects the side portion.
The vein harvesting device according to claim 6, further comprising a holding portion fixed to the first end of each respective side portion and projecting away from the respective side portion so that the side portions and the holding portion together define a space in which the vein is positioned during the harvesting of the vein, each of the projections possessing a center positioned at a location at which the holding portion intersects the side portion.
The vein harvesting device according to claim 6, wherein each side portion includes a bottom surface, the projection projecting higher than the bottom surface of the respective side portion.
The vein harvesting device according to claim 6, wherein each side portion possesses a distal-most end surface, each projection projecting distally beyond the distal-most end surface of the respective side portion.
A vein harvesting method for harvesting a vein in a body, the method comprising: contacting a distal end portion of a dissecting member and a projection of the dissecting member on a body while inclining the dissecting member to the body, inserting a distal end portion of the dissecting member that is positioned at a distal end of an elongated hollow member into the body after puncturing the body with the projection of the dissecting member and inserting the projection of the dissecting member into the body, the dissecting member being inserted into the body by operating the elongated hollow member, the dissecting member possessing a distal end portion and two spaced apart side portions projecting in a direction away from th positioning the dissecting member relative to the vein such that the vein is between the two side portions of t forward moving the dissecting member along the vein while the distal end portion of the dissecting member separates the vein from ti removing the dissecting
cutting and closing distal and proximal ends o and removing the separated vein from the body.
The vein harvesting method according to claim 11, further comprising cutting a side branch of the vein during the forward moving of the dissecting member by causing the side branch to enter a groove in one of the side portions and to be cut by a cutting member at an end of the groove.
The vein harvesting method according to claim 11, wherein the distal end portion of the dissecting member that separates the vein from other parts of the body is a projecting part of the dissecting member that projects distally beyond a distal-most end of the side portions.
The vein harvesting method according to claim 11, wherein the dissecting member further comprises a projection fixed to each of the side portions and projecting distally beyond a distal-most end of the side portions.
The vein harvesting method according to claim 11, wherein the dissecting member further comprises a projection fixed to each of the side portions and projecting below a lower-most surface of the side portions.
Description:
This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 62/240,663, U.S. Provisional Application No. 62/240,668, U.S. Provisional Application No. 62/240,797, and U.S. Provisional Application No. 62/240,834 filed on Oct. 13, 2015, the entire content of each of which is incorporated herein by reference.TECHNICAL FIELDThe present disclosure relates to a device for dissecting or harvesting a vein in a living body.BACKGROUND DISCUSSIONIt is known to use an artery graft (e.g., internal thoracic artery, gastroepiploic artery and radial artery) or a vein graft (e.g., great saphenous vein) as a bypass vessel in performing vascular bypass grafting at the heart (coronary artery bypass grafting: CABG). It has been reported that. at present, artery grafts (particularly, internal thoracic artery) offer higher long-term patency rates than vein grafts. Vein grafts are commonly thought to be poor in long-term patency rate. In recent years, however, it has been reported that the long-term patency rate of vein grafts is enhanced when the vein graft is harvested in a state in which the vein is covered by surrounding tissue (for example, fat, connective tissue, tissue between a skin layer and a muscle layer, tissue between a skin layer and an interosseous membrane, branch vessels, etc.) and is used as a bypass vessel while remaining covered with the tissue.Generally speaking, there are two primary techniques for harvesting blood vessels such as the saphenous vein. One technique is referred to as open vein harvesting. This technique involves making an elongated incision along, for example, the patient's limb (leg), and then carrying out the harvesting procedure for removing the blood vessel from the patient's limb. This technique has been found to be somewhat problematic in that it is rather invasive, requiring a rather extensive incision in the patient's limb. Harvesting site complications (e.g., infections) are also not uncommon.Another technique is referred to as endoscopic vein harvesting. This technique has some advantages over open vein harvesting in that the endoscopic vein harvesting is less invasive and has been found to have a lower incidence of infection. Unfortunately, endoscopic vein harvesting exhibits a lower patency rate because the harvested vein tends to be more damaged.SUMMARYThe devices and methods disclosed here provide a technique having an improved patency rate similar to the patency rate with the open vein harvesting, but without the harvesting site complications. The technique disclosed here is referred to as a no-touch technique. This technique improves endothelial integrity while reducing injury to the blood vessel (vein). It has also been found that this technique delays arterial atherosclerotic processes, conserves the vasa vasorum and it promotes the nitric oxide synthase activity of endothelial cells.According to one aspect, a vein harvesting device for harvesting a vein in a living body includes an elongated hollow member possessing a distal end portion and a proximal end portion, and a dissecting member at the distal end portion of the elongated hollow member and configured to dissect tissue in the body surrounding the vein during harvesting of the vein, wherein the dissecting member possessing a proximal end portion communicating with the elongated hollow member. The dissecting member possesses two side portions, with each of the side portions possessing a first end at an end of the side portion farther from the hollow member and a second end at an end of the side portion closer to the hollow member. A projection projects from the first end at each of the side portions of the dissecting member to contact the tissue in the body surrounding the vein during the harvesting of the vein.In accordance with another aspect, a vein harvesting device for harvesting a vein in a body comprises: an elongated hollow member possessing a distal end portion and a
and a dissecting member at the distal end portion of the elongated hollow member, with the dissecting member possessing a pair of spaced apart side portions projecting away from the distal end portion of the elongated hollow member, and with each side portion possessing a first end at an end of the side portion farther from the hollow member portion and a second end at an end of the side portion closer to the hollow member. The distal end portion of each side portion possesses a groove that is open at its distal end, extends toward the proximal end portion of the side member, and terminates at a cutting member configured to cut a side branch of the vein during harvesting of the vein, and a projection projects from each of the side portions of the dissecting member to contact a tissue in the body surrounding the vein during the harvesting of the vein.According to another aspect, a vein harvesting method for harvesting a vein in a body comprises: contacting the distal end portion of a dissecting member and a projection of the dissecting member on a body while inclining the dissecting member to the body, and inserting a distal end portion of the dissecting member that is positioned at a distal end of an elongated hollow member into the body after puncturing the body with the projection of the dissecting member and inserting the projection of the dissecting member into the body. The dissecting member is inserted into the body by operating the elongated hollow member, and the dissecting member possesses a distal end portion and two spaced apart side portions projecting in a direction away from the distal end portion. The method further includes positioning the dissecting member relative to the vein such that the vein is between the two side portions of t forward moving the dissecting member along the vein while the distal end portion of the dissecting member separates the vein from ti removing the dissecting
cutting and closing distal and proximal ends o and removing the separated vein from the body.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is a plan view of a blood vessel dissecting device according to a first embodiment of the present disclosure.FIGS. 2A and 2B illustrate a dissecting device forming a part of the blood vessel dissecting device shown in FIG. 1, wherein FIG. 2A is a longitudinal cross-sectional view and FIG. 2B is a transverse cross-sectional view taken along the section line 2B-2B of FIG. 2A.FIGS. 3A and 3B illustrate a cutting device forming a part of the blood vessel dissecting device shown in FIG. 1, wherein FIG. 3A is a plan view and FIG. 3B is a cross-sectional view taken along the section line 3B-3B of FIG. 3A.FIGS. 4A and 4B show views explaining a blood vessel dissecting method carried out using the blood vessel dissecting device shown in FIG. 1.FIGS. 5A and 5B show views explaining the blood vessel dissecting method carried out using the blood vessel dissecting device shown in FIG. 1.FIG. 6 is a perspective view of a dissecting device according to another embodiment.FIG. 7A is a side view of the dissecting member forming a part of the dissecting device illustrated in FIG. 6.FIG. 7B is a front view of the dissecting member forming a part of the dissecting device illustrated in FIG. 6.FIG. 7C is a front perspective view of the dissecting member forming a part of the dissecting device illustrated in FIG. 6.FIG. 7D is a bottom view of the dissecting member forming a part of the dissecting device illustrated in FIG. 6.FIG. 8A is a front view of the dissecting member forming a part of the dissecting device illustrated in FIG. 6 illustrating the positioning of the projections relative to the bottom surface of the dissecting member.FIG. 8B is a front view of another embodiment of the dissecting member forming a part of the dissecting device illustrated in FIG. 6.FIG. 9 is a front view of the dissecting member shown in FIG. 8A showing the way in which the dissecting member interacts with the vein and a side branch of the vein during use of the dissecting device.FIGS. 10A-10C are bottom perspective views of different embodiments of the dissecting member each possessing differently configured projections.FIG. 11A is an enlarged side view of the dissecting member illustrating the relative positions of different parts of the dissecting member.FIG. 11B is an enlarged side view of the dissecting member illustrating the relative positions of different parts of the dissecting member.FIG. 12 is an enlarged side view of the dissecting member illustrating the manner in which the dissecting member dissects the vein during use of the dissecting device.FIGS. 13-15 depict a bottom perspective view, a bottom view and a front view respectively of the dissecting member illustrating the frame bordering the window of the upturned distal end portion of the dissecting member.FIG. 16A is a front view of the dissecting member illustrating the way in which the dissecting member, by virtue of the window, interacts with the vein being dissected.FIG. 16B is a front view of a manner of interaction between a dissecting member without a window and a vein being dissected.FIG. 17A is a front view of the dissecting member illustrating the way in which the dissecting member and viewing member, by virtue of the window, interacts with the vein being dissected.FIG. 17B is a front view of a dissecting member without a window illustrating the way in which the dissecting member and the viewing member interact with the vein being dissected.FIGS. 18A and 18B are perspective and exploded views respectively of another embodiment of the dissecting device.FIG. 19 is a side view of the dissecting member forming a part of the dissecting device shown in FIG. 18.FIG. 20 is a front view of the dissecting member forming a part of the dissecting device shown in FIG. 18.FIG. 21 is a front view of the dissecting member forming a part of the dissecting device shown in FIG. 18 illustrating the way in which the dissecting member interacts with the vein being dissected.FIGS. 22a and 22B are perspective and exploded views respectively of another embodiment of the dissecting device.FIG. 23 is a side view of a part of the dissecting device shown in FIG. 22.FIG. 24 is a front perspective view of a part of the dissecting device shown in FIG. 22.FIG. 25 is a front view of the dissecting member forming a part of the dissecting device shown in FIG. 22 illustrating the way in which the dissecting member interacts with the vein being dissected.FIG. 26 is a side view of a part of the dissecting device shown in FIG. 22 illustrating the way in which the dissecting member interacts with a side branch of a vein being dissected.FIGS. 27A and 27B are perspective and exploded views of another embodiment of the dissecting device.FIG. 28 is a perspective view of the dissecting device shown in FIG. 27.FIG. 29 is a transverse cross-sectional view of the dissecting device shown in FIG. 27.FIG. 30 is a top perspective view of another embodiment of the dissecting device.FIG. 31A is a perspective view of a part of the dissecting member forming a part of the dissecting device illustrated in FIG. 30.FIG. 31B is a cross-sectional view of the dissecting member forming a part of the dissecting device illustrated in FIG. 30.FIG. 32A is a perspective view of a part of the covering member forming a part of the dissecting device illustrated in FIG. 30.FIG. 32B is a cross-sectional view of the covering member forming a part of the dissecting device illustrated in FIG. 30.FIG. 33A is a perspective view of a part of the dissecting member and covering member forming a part of the dissecting device illustrated in FIG. 30.FIG. 33B is a cross-sectional view of the dissecting member and covering member forming a part of the dissecting device illustrated in FIG. 30.FIG. 33C is a perspective view of the dissecting member and covering member forming a part of the dissecting device illustrated in FIG. 30.FIG. 34 is a perspective view of the covering member and the cutting member forming a part of the dissecting device illustrated in FIG. 30.FIG. 35 is a perspective view of the covering member and the cutting member, with a viewing forming a part of the dissecting device illustrated in FIG. 30.FIG. 36 is a cross-sectional view of the covering member and the cutting member forming a part of the dissecting device illustrated in FIG. 30.FIG. 37 is a top perspective view of another embodiment of the dissecting device.FIG. 38 is a bottom perspective view of the dissecting member forming a part of the dissecting device shown in FIG. 37 illustrating the viewing device positioned in the underside lumen.FIG. 39 is a bottom perspective view of the dissecting member forming a part of the dissecting device shown in FIG. 37 illustrating the field of view of the viewing device positioned in the underside lumen.FIGS. 40-42 are top perspective views of another embodiment of the covering member used in the disclosed dissecting devices.FIG. 43 is a perspective view of another embodiment of the cutting member used in the disclosed dissecting devices.FIG. 44 is a schematic side view of the cutting member shown in FIG. 43.FIG. 45 is an illustration of another embodiment of the cutting member used in the disclosed dissecting devices.DETAILED DESCRIPTIONExamples of a blood vessel dissecting device and a blood vessel dissecting method disclosed here will be described in detail below, referring to the attached drawings.FIGS. 1-5B illustrate a blood vessel dissecting device and blood vessel dissecting method carried out using the blood vessel dissecting device according to a first embodiment representing one example of the vein dissecting device and method disclosed here. In the following description, for convenience of explanation, the right side in FIG. 1 is referred to as the “distal” side or end, and the left side in the figure is referred to as the “proximal” side or end.A blood vessel (vein) dissecting device 100 shown in FIG. 1 is a device used to dissect or harvest a blood vessel for use as a bypass vessel in carrying out blood vessel bypass grafting (particularly, coronary artery bypass grafting: CABG). Using this blood vessel dissecting device 100, a blood vessel can be harvested in the state of being covered with the surrounding tissue (fat, connective tissue, etc.), preferably to the extent that the blood vessel is not exposed to the surface of the surrounding tissue and the blood vessel does not have the lateral surface that is exposed to the external atmosphere. More preferably, to the extent that an outer surface of the blood vessel is not exposed to the surface of the surrounding tissue and the outer surface of the blood vessel does not have the lateral surface that is exposed to the external atmosphere. The blood vessel to be harvested using the blood vessel dissecting device 100 is not particularly limited insofar as it is a blood vessel that can be used as a bypass vessel. Examples of the applicable blood vessel include internal thoracic artery, gastroepiploic artery, radial artery, and great saphenous vein.It is preferable, however, that the blood vessel to be harvested is the great saphenous vein. The blood vessel dissecting device 100 and method disclosed here facilitate harvesting or dissecting a blood vessel in the state in which the blood vessel is covered with the surrounding tissue. Harvesting the great saphenous vein using the blood vessel dissecting device 100 and method disclosed here, and using the harvested or dissected vein as a bypass vessel enhances long-term patency rate after the bypass grafting operation. In view of this, in the following, examples of harvesting or dissecting a great saphenous vein by use of the blood vessel dissecting device 100 and method disclosed here will be described as representative of a blood vessel to which the device and method disclosed here are applicable.As shown in FIG. 1, the blood vessel dissecting device 100 includes or possesses a dissecting device 200 and a cutting device 300. Both the dissecting device 200 and the cutting device 300 are devices which are inserted into a living body along the great saphenous vein. The dissecting device 200 and the cutting device 300 will now be described in detail below. The dissecting device 200 and the cutting device 300 may be used in other than a living body. For example, the dissecting device 200 and the cutting device 300 can be used with other bodies such as a cadaver and a simulator intended to simulate the living body.The dissecting device 200 has an elongated bar-like shape (bar-shaped) extending substantially straight, and is provided at its distal end with a dissecting section 220 for dissecting tissue. In addition, as shown in FIG. 2B, the dissecting device 200 has a flat shape (flattened shape as seen in vertical cross-section to a central axial direction of the dissecting device) in section. The cross-sectional shape of the dissecting device 200 is not spe for example, the cross-sectional shape may be a crushed-circle-like shape (flattened circular shape), such as an oblong and an ellipse, a rectangle rounded at corners, or the like.The width (the length in the major axis direction of the cross-sectional shape) W1 of the dissecting device 200 is greater than the outside diameter of the blood vessel to be harvested (in this embodiment, the great saphenous vein). To be more specific, the width W1 is preferably about 4 mm to 2 cm greater than the outside diameter of the blood vessel to be harvested. This helps ensure that the possibility of contact between the cutting device 300 and the great saphenous vein can be effectively lowered at the time of inserting the cutting device 300 into the living body along the dissecting device 200, as will be explained in the “blood vessel harvesting method” described later.In addition, the dissecting device 200 is provided, at both ends of the major axis of the cross-sectional shape thereof, with rails 231 and 232 in the form of linear stretches of recess (or trenches/grooves) which extend in the axial direction of the dissecting device 200. Each of the rails 231 and 232 is used for connection of the dissecting device 200 with the cutting device 300, and functions as a guide section for guiding the cutting device 300. Note that the rails 231 and 232 are not limited to the linear stretches of recess (or trenches/grooves) but may be, for example, linear stretches of projection (or ridges or ribs), insofar as they each enable connection of the dissecting device 200 with the cutting device 300.As shown in FIG. 2A, the dissecting device 200 is provided with an insertion hole 210 which opens at the proximal end and extends to a distal portion (the dissecting section 220). In this illustrated embodiment, the insertion hole 210 is a blind hole, meaning the insertion hole 210 is closed at its distal end. Into the insertion hole 210 is inserted an imaging device 400. The imaging device 400 is not specifically restricted. For example, the imaging device 400 in this embodiment, as depicted in FIG. 2A, includes or possesses an elongated main body section 410, and an illuminating section (not shown) for emitting illumination light and an imaging section 430 for imaging the front side of the dissecting device 200. The illuminating section and the imaging section 430 are disposed at a distal portion of the main body section 410. The imaging section 430 includes or possesses, for example, an objective lens system disposed at the distal portion of the main body section 410 and an imaging element (e.g., solid state image sensor such as CMOS image sensor or CCD sensor) disposed opposite to the objective lens system.The dissecting section 220 is tapered in a narrowing manner toward the distal end of the dissecting device 200. More specifically, the distal end portion of the dissecting section 220 possesses a tapered roughly conical shape so that the length in the minor axis direction and the length in the major axis direction of the cross-sectional shape of the dissecting section 220 are both gradually decreased in a direction toward the distal end. Such a dissecting section 220 is blunt in the thickness direction, and has such a degree of sharpness (bluntness) as to be able to dissect tissues having different properties (for example, fat and skin, fat and fascia, fat and blood vessel, fat and bone, etc.) from each other without cutting branch vessels branched from the great saphenous vein. This helps ensure that a dissecting function can be sufficiently exhibited and the branch vessels are restrained from being damaged or cut by the dissecting section 220. Accordingly, bleeding can be suppressed, and the intended technique can be performed safely and smoothly. Note that the shape of the dissecting section 220 is not particularly limited insofar as it enables dissection of tissues in the thickness direction (minor axis direction) of the tissues. For example, the dissecting section 220 may be in the shape of a duck-bill such that the length in the minor axis direction of the cross-sectional shape of the dissecting section 220 is gradually decreased (tapered) toward the distal end and the cross-sectional shape at the distal end is a line segment along the major axis direction.The dissecting section 220 is substantially colorless and transparent and is light-transmitting. This helps ensure that when the imaging device 400 is inserted into the insertion hole 210, the front side of the dissecting device 200 can be observed through the dissecting section 220 by the imaging device 400. In other words, the dissecting section 220 has the function as an observation section for observation of the inside of the living body (the great saphenous vein and its surroundings), in addition to the aforementioned function as the dissecting section. Note that the dissecting section 220 is not limited to the colorless transparent property but may be colored in red, blue, green or the like, insofar as it is light-transmitting.The cutting device 300, at the time of moving along a great saphenous vein 1000, cuts the fat (inclusive of connective tissue) surrounding the great saphenous vein 1000 and, in addition, cuts and stanches the branch vessels branched from the great saphenous vein 1000.The cutting device 300 is elongated plate-like in shape (plate-shaped). As shown in FIGS. 1 and 3A, the cutting device 300 has a groove portion 320 opening in a distal portion of the cutting device. The groove portion 320 possesses: a tapered blood vessel guide groove section (first groove section) 321 having a width gradually decreasing towa and a straight blood vessel treating groove section (second groove section) 322 which is located on the proximal side of the blood vessel guide groove section 321 and is substantially constant in width. The blood vessel guide groove section 321 is a groove section for guiding a branch vessel into the blood vessel treating groove section 322 at the time of pushing the cutting device 300 forward in a living body, and is tapered in shape for the guiding to be smoothly achieved. On the other hand, the blood vessel treating groove section 322 is a groove section for cutting and stanching the branch vessel guided to the blood vessel treating groove section 322 by the blood vessel guide groove section 321. Further, the blood vessel treating groove section 322 is provided with a treating section 330 for cutting and stanching a branch vessel.As shown in FIG. 3A, the treating section 330 has a bipolar structure including a pair of electrodes 331 and 332 configured to generate an electric field inside the blood vessel treating groove section 322. The electrode 331 is disposed at a proximal end portion of the blood vessel treating groove section 322, while the electrode 332 is disposed on both sides with respect to the width direction of the blood vessel treating groove section 322. With a high-frequency AC voltage impressed between the electrodes 331 and 332, it is possible to heat and cut a branch vessel 1100 guided into the blood vessel treating groove section 322 and to stanch the blood vessel through thermal coagulation. A distal portion (a portion exposed to the blood vessel treating groove section 322) 331a of the electrode 331 is preferably so sharp as to be able to cut the branch vessel 1100. This helps ensure that if thermal coagulation (stanching) of the branch vessel 1100 can at least be achieved by the electric field generated between the electrodes 331 and 332, the branch vessel 1100 can be physically cut by the distal portion 331a of the electrode 331. Accordingly, the assuredness of the treatment by the treating section 330 is enhanced.The width W2 of the blood vessel treating groove section 322 is not particularly limited but it is preferably narrower than the outside diameter of the branch vessel 1100. This helps ensure that the branch vessel 1100 can be pressed flat inside the blood vessel treating groove section 322 as shown in FIG. 3A, and, consequently, the treatment (cutting and stanching) at the treating section 330 can be performed more reliably.The cutting device 300 is provided with a cutting edge section (cutting section) 350 for cutting the fat surrounding the great saphenous vein 1000. The cutting edge section 350 is disposed at a distal portion of the cutting device 300; in this embodiment, it is disposed along the blood vessel guide groove section 321. As will be explained also in the “blood vessel harvesting method” described later, the cutting edge section 350 has the function of cutting the fat surrounding the great saphenous vein 1000 at the time of pushing the cutting device 300 forward in the living body. Such a cutting edge section 350 preferably has such a sharpness as to be able to cut the fat without cutting the branch vessel 1100. This helps ensure that cutting of the branch vessel 1100 by the cutting edge section 350 is inhibited, so that bleeding is restrained, and the intended technique can be performed safely and smoothly.As shown in FIG. 3B, the cutting device 300 has a pair of protection sections 341 and 342 provided on both sides with respect to the cutting device's width direction (the direction orthogonal to its moving direction). The protection sections 341 and 342 each extend along the axial direction of the cutting device 300, and their peripheral surfaces (side surfaces and distal surfaces) are rounded. As will be explained also in the “blood vessel harvesting method” described later, the protection section 341 moves along and between fat and skin while dissecting them from each other, at the time of pushing the cutting device 300 toward the distal side in a living body. Since the fat and the skin having different properties, they are rather easy to dissect from each other, even though a distal end portion of the protection section 341 is rounded, and the dissecting function of dissecting the fat and the skin from each other can be exhibited sufficiently. In addition, the rounding helps ensure that a branch vessel can be restrained from being damaged or cut by the protection section 341, and, further, damage to (cauterization of) the skin due to sliding against (friction with) the protection section 341 can be restrained. Similarly, the protection section 342 moves along and between the fat and the fascia while dissecting them from each other at the time of pushing the cutting device 300 toward the distal side in the living body. Since the fat and the fascia having different properties, they are easy to dissect from each other, even though a distal end portion of the protection section 342 is rounded, and the dissecting function of dissecting the fat and the fascia from each other can be exhibited sufficiently. Besides, the rounding helps ensure that the branch vessel can be restrained from being damaged or cut by the protection section 342, and, further, damage to (cauterization of) the fascia due to sliding against (friction with) the protection section 342 can be restrained.As shown in FIGS. 3A and 3B, the cutting device 300 has connection sections 381, 382, 383 and 384 configured to connect with the rails 231 and 232 of the dissecting device 200. The connection sections 381 and 382 are provided at the protection section 341, and disposed on mutually opposite surface sides. Similarly, the connection sections 383 and 384 are provided at the protection section 342, and disposed on mutually opposite surface sides. These connection sections 381 to 384 are composed of stretches (lengths) of projection (or ridges or ribs) which extend in the axial direction of the cutting device 300 and correspond to the stretches of recess (trenches) of the rails 231 and 232. Since such connection sections 381 to 384 are provided, unintended detachment of the dissecting device 200 and the cutting device 300 from each other is prevented, so that the intended technique can be carried out more smoothly and accurately. Thus, in this example of the blood vessel dissecting device, both the cutting device 300 and the dissecting device 200 possess connection structure configured to connect the cutting device 300 and the dissecting device 200 to each other.A method of harvesting or dissecting a blood vessel by use of the blood vessel dissecting device 100 possesses: a first step (blood vessel dissecting method) of dissecting the great saphenous vein 1000 in the state of being covered with surrounding fat 1200 by use of the blood vessel dissecting device 100; a second step of ligating the great saphenous vein 1000 and then cutting the great saphenous vein 1000; and a third step of extracting the great saphenous vein 1000 in the state of being covered with the surrounding fat 1200 from the living body.First, the position of the great saphenous vein 1000 to be harvested is confirmed, and skin is incised on the basis of the position of the great saphenous vein. Next, the dissecting device 200 with the imaging device 400 inserted in the dissecting device 200 is prepared, and, while observing the inside of the living body by the imaging device 400, the dissecting device 200 is inserted from the incision 1300 into the living body along the great saphenous vein 1000 while keeping the dissecting device 200 spaced from the great saphenous vein 1000. Then, as shown in FIG. 4A, the dissecting device 200 is disposed on the upper side (the skin 1400 side) of the great saphenous vein 1000. In this case, the dissecting device 200 is so disposed that the thickness direction of the dissecting device 200 agrees substantially with the aligning direction in which the dissecting device 200 and the great saphenous vein 1000 are aligned. In this operation, the dissecting device 200 is inserted between the fat 1200 and the skin 1400 (between the tissues having different properties), and the skin 1400 and the fat 1200 are dissected from each other in the thickness direction of the dissecting device 200 (in the aligning direction in which the dissecting device 200 and the great saphenous vein 1000 are aligned). Such an area is an area where dissection can be achieved particularly easily, so that this operation can be carried out more smoothly and accurately. The dissecting device 200 thus dissects tissue in a direction along the longitudinal extent of the vein.Subsequently, the cutting device 300 is prepared, and the connection section 381 is connected to the rail 231 of the dissecting device 200. Then, the state of the dissecting device 200 is aligned on the upper side of the great saphenous vein 1000, the cutting device 300 is inserted into and moved in the living body while guiding the cutting device 300 with the dissecting device 200 as shown in FIG. 4B. In this case, the cutting device 300 is moved forward while dissecting the skin 1400 from the fat 1200 by the protection section 341, and while dissecting the fascia 1500 from the fat 1200 by the protection section 342. Furthermore, the cutting device 300 cuts the fat 1200 present on the one lateral side of the great saphenous vein 1000 by the cutting edge section 350 in the left-right direction (in the aligning direction in which the cutting device 300 and the great saphenous vein 1000 are aligned), and, concurrently, cuts and stanches the branch vessel 1100 by the treating section 330.Here, since the width W1 of the dissecting device 200 is greater than the outside diameter of the great saphenous vein 1000 as aforementioned, the cutting device 300 can be pushed forward along the great saphenous vein 1000 while keeping the cutting device 300 laterally spaced from the great saphenous vein 1000, as shown in FIG. 4B, so that the great saphenous vein 1000 can be prevented from being damaged during this operation. In addition, since the protection sections 341 and 342 are rounded, the possibility of damaging the skin 1400 or the fascia 1500 by contact with the cutting device 300 is lowered.Next, the cutting device 300 is drawn out, and the connection section 382 of the cutting device 300 thus drawn out is connected to the rail 232 of the dissecting device 200. Then, the cutting device 300 is inserted again into the living body while guiding the cutting device 300 with the dissecting device 200, to dispose the cutting device 300 on the other lateral side of the great saphenous vein 1000, as shown in FIG. 5A.Subsequently, the dissecting device 200 is drawn out, and the rail 232 of the dissecting device 200 thus drawn out is connected to the connection section 384 of the cutting device 300. Then, the dissecting device 200 is inserted again into the living body while guiding the dissecting device 200 with the cutting device 300, to dispose the dissecting device 200 on the lower side (the fascia 1500 side (bone side)) of the great saphenous vein 1000, as shown in FIG. 5B. In this operation, the dissecting device 200 is inserted between the fat 1200 and the fascia 1500 (inserted into the boundary between the tissues having different properties), and the fat 1200 and the fascia 1500 are dissected from each other in the thickness direction of the dissecting device 200. Such an area is an area where dissection can be particularly easily achieved, so that this operation can be carried out more smoothly and accurately.By the above-mentioned operations, the fat 1200 surrounding the great saphenous vein 1000 is dissected over the entire perimeter of the vein, and the great saphenous vein 1000 is dissected in the state of being covered with the surrounding fat 1200. The thickness of the fat 1200 dissected together with the great saphenous vein 1000 and located in the surroundings of the great saphenous vein 1000 is not particularly limited. It is preferable, however, that the thickness is about 0.1 mm to 10 mm, more preferably about 1 mm to 8 mm, and further preferably about 3 mm to 5 mm.Next, both ends of that part of the great saphenous vein 1000 which is to be harvested are ligated and then cut.Subsequently, the great saphenous vein 1000 is extracted in the state of being covered with the surrounding fat 1200, to the outside of the living body via the incision 1300.By the first to third steps as above-mentioned, the great saphenous vein 1000 can be harvested while the great saphenous vein is in the state of being covered with the surrounding fat 1200. In such a method, while using the dissecting device 200 for treating a part which is rather easy to dissect so as to reduce such damages as bleeding and while using the cutting device 300 for treating the fat which is difficult to dissect, the great saphenous vein 1000 can be harvested smoothly and with low invasion. In addition, since the first step can be carried out without cutting the great saphenous vein 1000, blood can be kept flowing through the great saphenous vein 1000 for a time as long as possible. Accordingly, the great saphenous vein 1000 is placed in an ischemic state for a shortened period of time, so that the great saphenous vein 1000 can be harvested with less damage.Here, a great saphenous vein 1000 covered with fat 1200 constitutes a bypass vessel having a superior long-term patency rate, as compared with a great saphenous vein 1000 not covered with fat 1200. The reason is considered as follows. While the great saphenous vein 1000 is used as an artery bypass vessel, arteries are generally higher than veins in the blood pressure (the internal pressure exerted thereon by blood). When a great saphenous vein in an exposed state of being not covered with tissue is used as a bypass vessel, therefore, the great saphenous vein cannot endure the blood pressure and is therefore expanded by the blood pressure, resulting in lowered blood flow. In addition, thickening of blood vessel wall occurs in the process of remodeling (structural alteration) or in the process of recovery from damage to tissue. Such thickening of blood vessel wall is considered to influence the development of arterial sclerosis. From such a cause, the use of a great saphenous vein in the exposed state of being not covered with tissue as a bypass vessel would, in the long run, lead to vascular occlusion.On the other hand, where the great saphenous vein 1000 is covered with fat 1200, expansion of the great saphenous vein 1000 is restrained by the fat 1200, and bending and the like of the great saphenous vein 1000 are also restrained. Therefore, the lowering in blood flow as above-mentioned can be inhibited. In addition, the covering with the fat 1200 reduces damages to the great saphenous vein 1000, specifically, damages to endotheliocytes, smooth muscles, nutrient vessels (capillary plexus), etc. Therefore, the aforementioned thickening of blood vessel walls can be restrained. For these reasons, the use of the great saphenous vein 1000 covered with the fat 1200 as a bypass vessel enables an excellent long-term patency rate. Especially, in this embodiment, nutrient vessels are left at the blood vessel walls of the great saphenous vein 1000 and in the fat 1200. For this reason, nutrients are supplied to the great saphenous vein 1000 serving as the bypass vessel, even after the bypass grafting. This is considered to be the reason why the aforementioned effect is enhanced.While this embodiment has been described, the configuration of the blood vessel dissecting device 100 is not limited to the configuration in this embodiment. For example, the rails 231 and 232 may be omitted from the dissecting device 200, and the connection sections 381 to 384 may be omitted from the cutting device 300. In this case, for example, it may be sufficient to insert the cutting device 300 into a living body along the dissecting device 200 which is inserted into the living body earlier. Alternatively, it may be sufficient to insert the dissecting device 200 into a living body along the cutting device 300 which is inserted into the living body earlier.The cutting device 300 is not specifically restricted insofar as it can cut the fat 1200. For instance, a configuration may be adopted in which the fat 1200 is cut by something like a pair of scissors.The blood vessel dissecting method is not limited to the procedure adopted in this embodiment. For instance, the order of insertion of the dissecting device 200 and the cutting device 300 is not specifically restricted, and any of left, right, upper and lower portions of the great saphenous vein 1000 may be dissected first. For instance, a procedure may be adopted in which, first, upper and lower sides of the great saphenous vein 1000 are dissected by use of the dissecting device 200, and, then, left and right sides of the great saphenous vein 1000 are dissected by use of the cutting device 300. On the other hand, left and right sides of the great saphenous vein 1000 may first be dissected by use of the cutting device 300, and, then, upper and lower sides of the great saphenous vein 1000 may be dissected by use of the dissecting device 200.While one dissecting device 200 and one cutting device 300 are used in this embodiment, two dissecting devices 200 and two cutting devices 300 may be used. In this case, for example, a procedure may be adopted wherein, first, a first dissecting device 200 is disposed on the upper side of the great saphenous vein 1000, next a first cutting device 300 is disposed on one of left and right sides of the great saphenous vein 1000, then a second cutting device 300 is disposed on the other of the left and right sides of the great saphenous vein 1000, and a second dissecting device 200 is disposed on the lower side of the great saphenous vein 1000. Such a procedure eliminates the need to draw out the dissecting device 200 and the cutting device 300 in the course of the procedure, so that the aforementioned procedure can be carried out smoothly.While the dissecting device 200 is inserted between the fat 1200 and the skin 1400 and between the fat 1200 and the fascia 1500 in this embodiment, the insertion position of the dissecting device 200 is not particularly limited. For instance, the dissecting device 200 may be inserted between tissues having different properties, such as between the fat 1200 and a blood vessel (other than the great saphenous vein 1000), between the fat 1200 and a bone, between the fascia 1500 and a bone, or the like. Further, the insertion between tissues having different properties (insertion into the boundary between tissues having different properties, insertion into tissue between tissues having different properties, or the like) for example, the dissecting device 200 may be inserted into the fat 1200, thereby dissecting the fat 1200.While fat is cut by the cutting device 300 in this embodiment, the tissue to be cut by the cutting device 300 is not limited to fat. For instance, tissue between a skin-fat boundary and a fat-muscle boundary, tissue between a skin-fat boundary and a fat-interosseous membrane boundary, connective tissue, tissue between a skin layer and a muscle layer, tissue between a skin layer and an interosseous membrane, branch vessels, and the like may also be cut by the cutting device 300.In this embodiment, the dissecting device 200 is disposed spaced from the great saphenous vein 1000 so as not to contact the great saphenous vein 1000. But the dissecting device 200 may be disposed in contact with the great saphenous vein 1000. In other words, the dissecting device 200 may be inserted between the great saphenous vein 1000 and the fat 1200.FIG. 6 illustrates another embodiment of a vein dissecting or harvesting device. This embodiment of the vein dissecting device 500 includes or possesses a dissecting member 508 which incorporates a cutting member 518. The vein dissecting device 500 also includes or possesses an elongated hollow member 502 projecting rearwardly (in the proximal direction) from the dissecting member 508. The elongated hollow member 502 possesses a proximal end portion 504 and a distal end portion 506, and the dissecting member 508 is mounted on or fixed to the distal end portion 506 of the elongated hollow member 502.FIGS. 7A-7D depict the dissecting member 508 in more detail. Those figures illustrate that the dissecting member 508 possesses a mount 512 that may be generally tubular in configuration. By way of this mount 512, the dissecting member 508 is mounted on the distal end portion 506 of the elongated hollow member 502. This can be accomplished by, for example, welding, adhesive, fitting together, etc. Projecting from the mount 512 are two spaced-apart side portions or side walls 514. In the illustrated embodiment, these side portions 514 project vertically downwardly away from the mount 512 as best illustrated in FIG. 7B. The dissecting member 508 also includes or possesses holding portions 520, each of which projects inwardly from one of the side portions 514. In the illustrated embodiment, the holding portions 520 are horizontally oriented and project inwardly towards one another as generally illustrated in FIG. 7B. The holding portions 520 are preferably configured and arranged to retain dissected tissue and/or the vein.The mount 512 defines a top portion which, together with the two spaced-apart side portions 514 and the two holding portions 520, defines a space or region 513. As described in more detail below, this region 513 represents a vein-receiving region or space configured to receive the vein (e.g., saphenous vein) during use and operation of the dissecting device 500. An example of this is shown in FIG. 9 which schematically illustrates the dissecting member 508 during use. As the dissecting member 508 is moved along the vein 1000 during use, the vein 1000 is received or positioned in the vein-receiving region or space 513 defined between the holding portions 520, the side portions or side members 514 and a part of the mount 512 forming an upper confine.As best illustrated in FIGS. 7A and 7C, the distal end portion 510 of the dissecting member 508 is configured as an upturned member. According to one embodiment as illustrated, the upturned member 510 may be in the form of an upwardly curved member that is curved along at least its distal end portion of its extent in an upward direction. The upturned distal end portion 510 of the dissecting member 508 constitutes an upwardly curved protrusion member. FIG. 11 shows that the upturned or curved distal end portion 510 of the dissecting member 508 can be configured to possess the distal end portion that is upwardly curved and a proximal portion 517 that is linear or straight. As will be explained in more detail below, the upturned or upwardly curved distal end portion 510 is configured to curve away from the vein during use of the dissecting device 500. The upturned or upwardly curved distal end portion 510 is preferably made of transparent material. This can help facilitate viewing a position of the vein with a viewing device and facilitate moving the viewing device along the vein.Each of the side members 514 includes or possesses a groove 516 that is open at one end (i.e., the forward or distal end on the left as illustrated in FIG. 7A) and closed at the opposite end. At the closed end, the groove terminates in a curved section representing a cutting member 518. The grooves 516 and the cutting members 518 are preferable configured in a way that facilitates cutting of, for example, side braches of the vein. That is, side branches projecting from the vein, such as the side branches 1100 shown in FIGS. 4A, 4B, 5A and 5B, can be captured and guided in the grooves 516 and cut by the cutting member 518. To facilitate cutting, the cutting members 518 can be sharpened or otherwise provided with a cutting edge.The dissecting member 508 also possesses several projections 522. Each projection 522 is positioned at the front surface or front side of one of the side portions 514, generally at a position where each side portion 514 intersects the respective holding portion 520 as best illustrated in FIG. 7B.The projections 522 help facilitate smooth insertion of the dissecting device 508 into the living body and relatively smooth movement of the dissecting device along the vein (e.g., saphenous vein) during the dissecting operation. As described in more detail below, the method of use or operation can involve initially contacting the distal end portion of the dissecting member and the projections 522 of the dissecting member on a living body while the dissecting device is inclined to the body, and then inserting the distal end portion of the dissecting member into the body after puncturing or sticking the body with the projection and inserting the projection into the living body.The projections 522 are preferably positioned so that they are located superior to (i.e., vertically above) the bottom surface of the dissecting device (e.g., the bottom surface of the holding portions 520). The projections 522 are preferably located superior to the bottom surface of the dissecting device in FIG. 8B.In the embodiment of the dissecting member 508 illustrated in FIGS. 7A-7D and FIG. 8A, the side portions or side members 514 are straight vertically oriented members, the holding portions 520 are straight horizontally oriented members, and the holding portions 520 are perpendicular to the respective side portions 514. The dissecting member 508 is not limited to this particular configuration. FIG. 8B shows an alternative configuration of the dissecting member in which the side portions or side members 514′ are curved generally inwardly towards one another and the holding portions 520′ are curved generally inwardly towards one another. It is also possible to implement other configurations, such as one in which the side portions are straight and the holding portions are curved, and another one in which the side portions are curved and the holding portions are straight.The dissecting member 508 may be configured such that the mount 512, the side portions 514, the holding portions 520, the projections 522 and the upturned distal end portion 510 are formed as an integrated and unitary part.The embodiment of the dissecting member 508 shown in FIGS. 7A-7D includes or possesses projections 522 in the form of spherical members positioned at the intersection of the side portion and the holding portion. The projections are not limited to this configuration and positioning. FIGS. 10A-10C illustrate several other embodiments of the projections. In these different embodiments, the projections are differently configured and arranged relative to the version shown in FIGS. 7A-7D. In FIG. 10A, the projections 522′ are configured as cone-shaped or bullet-shaped projections at the corner where the side portion 514 meets or intersects the holding portion 520. The projection 522″ in FIG. 10B is formed by a tapering part of the holding portion 520 at which the front edge of the holding portion tapers to a rounded point at the midpoint of the holding portion 520. The embodiment of the projection 522′″ in FIG. 10C is similar to FIG. 10B, but additionally includes or possesses the spherically shaped projection at the tapered midpoint of the holding portions. The pointed nature of the projections shown in FIGS. 10 A and 10B facilitate dissecting and sticking the tissue.As generally illustrated in FIG. 11, it is preferable that the projections 522 be positioned so that the entirety of the groove 516 in each of the side portions 514 is located posterior to the projection 522 (i.e., behind, proximal to or to the right of the projection 522 in FIG. 11). Stated differently, the projection 522 on each of the side portions or side members 514 is positioned in front of or on the distal side of the groove 516 (i.e., to the left of the groove in FIG. 11). The groove 516 on each of the side portions 514 is also preferably located posterior to (i.e., below) the upturned distal end portion 510 of the dissecting member 508 as also illustrated in FIG. 11. The groove 516 in each of the side portions 514 is positioned superior to or above the projections 522 as also depicted in FIG. 11A. FIG. 11A also shows that the projections 522 are positioned posterior to (i.e., behind or proximal to) the upturned distal end portion 510 of the dissecting member 508. The projections 522 on each of the side portions 514 are also located under or below the bottom surface 511 of the upturned distal end portion 510.A method of using the dissecting device 500 shown in FIGS. 6, 7A-7D, 8A and 8B to harvest or dissect a blood vessel (e.g., a vein such as a saphenous vein) may be generally similar to the method described above. That is, the method may involve using the dissecting device 500 to dissect the blood vessel in a condition in which the blood vessel is covered with surrounding fat (e.g., some of the fat 1200 shown in FIGS. 4A, 4B, 5A and 5B), ligating and cutting the blood vessel, and then removing the severed or dissected blood vessel in a condition in which the blood vessel is covered with surrounding fat from the living body. More specifically, the position of the blood vessel to be dissected or harvested (e.g., great saphenous vein 1000 shown in FIGS. 4A, 4B, 5A and 5B) to be harvested is identified or confirmed, and an incision is then made in the living body (e.g., leg of a patient) to provide an access site to the vein (saphenous vein) as well as the saphenous fascia surrounding the vein. The living body is incised based on the confirmed or determined position of the blood vessel. Holding the elongated member 502 of the dissecting device 500 (or another operating member connected to the elongated member 502), the user may then insert the dissecting member 508 of the dissecting device 500 into the living body by way of the incision. The dissecting member 508 is then manipulated or moved to generally position the dissecting member 508 relative to the vein 1000 in the manner illustrated in FIG. 9. In this position, the vein 1000 is located in the region or area 513 surrounded by the holding portions 520, the side portions 514 and the top portion defined by the mount 512. FIG. 9 illustrates the positioning of the dissecting member 508 from the front (i.e., as viewed along the vein 1000).FIG. 12 illustrates the dissecting member 508 from the side as the dissecting member 508 is moved along the vein 1000. FIG. 12 illustrates that as the dissecting member 508 is moved along the vein 1000 in the forward or distal direction indicated by the arrow (i.e., to the left in FIG. 12) the upturned member 510 constituting the distal end portion of the dissecting member lifts and separates fat tissue 1200 from the vein 1000. The fat tissue is peeled away in much the same way as an adhesive sticker is peeled off its backing. This peeling result is illustrated in FIG. 12. By virtue of the curved or upturned distal end portion 510 of the dissecting member 508, potentially damaging contact between the distal end portion of the dissecting member and the vein 1000 is reduced. The curved or upturned member 510 thus advantageously helps to avoid injury to the vein 1000. If the distal end portion of the dissecting member was configured as a straight distal end portion (i.e., no curved configuration), it would be more likely for the distal end portion of the dissecting member to contact the vein, for example by virtue of the distal-most end of the dissecting member poking or sticking the vein. The upturned distal end portion 510 of the dissecting member facilitates dissection or separation of the tissue from the vein. The upturned member possesses only a limited circumferential extent (i.e., the upturned distal end portion 510 does not extend 360°). The method of use or operation can thus involve forward moving the dissecting member for a relatively short distance, rotating the dissecting device to dissect a circumferential region, forward moving the dissecting device so that the upturned member helps dissects a different circumferential region, forward moving the dissecting device, etc.As the dissecting member 508 moves along the vein 1000, the dissecting device may encounter side branches of the vein 1000. Examples of such side branches are shown in FIGS. 4A, 4B, 5A, 5B and identified as 1100. By appropriately aligning the side branch 1100 with the groove 516 in one of the side portions 514, the side branch may enter the groove 516 as the dissecting member 508 is moved forward and will be cut by the cutting member 518.After the dissecting member 508 is advanced along the entire longitudinal extent of the vein 1000 that is to be dissected or removed, the dissecting member 508 is moved in the rearward or proximal direction (i.e., to the right in FIG. 12). The dissecting member 508 can then be rotated, for example, by ninety (90) degrees, and then once again inserted into the living body to dissect the tissue surrounding the vein 1000 (i.e., the fat 1200) from the vein 1000 at circumferential location different from the dissection performed by the first pass of the dissecting member 508 along the vein 1000. This procedure can be repeated as many times as necessary to dissect the tissue from the vein so that the vein (and tissue surrounding the vein) is separated from adjacent tissue. It may be necessary to perform several passes of the dissecting member 508 as described. With the dissecting member 508 preferably removed from the living body, the ends of the dissected vein are then ligated and cut, and the severed vein is then removed from the living body.To further facilitate the smooth introduction of the dissecting member 508 into the living body and movement of the dissecting member 508 along the vein, the projections 522 are preferably positioned relative to the upturned or curved distal end portion 510 of the dissecting member 508 so that the projections 522 are located posterior to (rearward of or proximal to) a tangent to the bottom surface of the upturned or curved distal end portion 510 of the dissecting member 510 as illustrated in FIG. 11B. In the embodiment shown in FIG. 11B, the bottom surface of the upturned member 510 constituting the distal end portion of the dissecting member possesses a flat region 515, and the tangent line 523 represents a continuation of this flat bottom surface portion 515 of the upturned member 510. The upturned member 510 is prefe