WO1999025238A2

WO1999025238A2 - Device for endoscopic vessel harvesting

Info

Publication number: WO1999025238A2
Application number: PCT/US1998/024644
Authority: WO
Inventors: John D. Puskas
Original assignee: Emory University
Priority date: 1997-11-18
Filing date: 1998-11-18
Publication date: 1999-05-27
Also published as: CA2310426A1; WO1999025238A3; AU1590799A

Abstract

An endoscopic device (8) provides improvements in the endoscopic working space by the use of a semi-tubular hood (3) with an arched top wall, self-supporting sidewalls that allow simultaneous manipulations of dissection, cutting, ligation, retraction, and the like, without requiring constant application of external force. The endoscopic device (8) enhances visualization, and reduces the need for cleaning the endoscopic lens (12).

Description

DEVICE FORENDOSCOPIC VESSEL HARVESTING

BACKGROUND OF THE INVENTION

Vessel harvesting has traditionally required skin incisions as long as the

length of the vessel removed. This technique produces long scars and may result

in healing difficulties. The present invention addresses the need for less invasive

removal of vessels. It is adaptable to a wide variety of surgical procedures,

including harvesting saphenous vein for peripheral vascular surgery or for

coronary artery bypass grafting.

Generally, minimally invasive vessel harvesting with an endoscope is

known in the surgical field. In one procedure, a vessel is removed with an

endoscope having a lumen therethrough. In this procedure, the saphenous vein is

held with a grasper which is introduced through the lumen of the endoscope.

After connective tissue has been dissected from around the vein, the vein is then

ligated and transected and removed from the lower limb of the patient through the

lumen of the endoscope. See, SU 1371689. Although this method provides for a minimally invasive technique, there

are several associated drawbacks. First, in practicing this method there is limited

visibility of the saphenous vein and its side branches because viewing is limited to

the immediate area directly in front of the endoscope. Secondly, the illumination

within the subcutaneous space created by this type of endoscope is also limited to

the light emitted directly at the distal portion of the endoscope. Another

drawback is that the side branches of the saphenous vein limit the maneuverability

of the endoscope since the outer edge of the endoscope body is prevented from

advancing along the trunk of the saphenous vein until the encountered side

branches are ligated and transected thereby. Perhaps most important, methods

which utilize this type of endoscope, i.e. an endoscope having a lumen, provide a

working space which is very restricted because the side walls of the scope body

confine the working instrumentation to a very limited area. An additional problem

is that the lens of the endoscope becomes soiled after touching tissue, so it must

be withdrawn and cleaned periodically during vessel dissection and retraction.

Furthermore, the vessel harvesting method described above is typically a

three-handed approach which actually requires more than one individual. In this

method, one hand is required to hold and maintain the endoscope in position,

while a second hand is required to hold the free end of the transected vessel with a

grasper and a third hand is required to dissect connective tissue away from the

vessel. 2 Another method for harvesting the saphenous vein is disclosed in "Vein

Harvest", Alan B. Lumsden and Felmont F. Eaves, III, in Endoscopic Plastic

Surgery (Quality Medical Publishing, Inc., 1995), pp. 535-543. This method

provides for performing a preliminary dissection of the saphenous vein while

using an open techmque prior to inserting an endoscopic retractor such as those

commonly used in plastic surgery. In this procedure, once the subcutaneous

tissue is retracted with the endo-retractor, a pair of scissors is used to dissect the

superior surface of the saphenous vein in order to expose the vein.

A method using both an optical dissector and an optical retractor has been

described for endoscopic removal and harvesting of blood vessels. See U.S. Patent

No. 5,667,480. The devices described therein need frequent cleaning of the small

endoscopic lens during harvesting, due to the shallow working space beneath the

platform and the position of the endoscope within the working head and platform.

Also, when multiple instruments, such as a dissector and a retractor, are needed to

perform harvesting, they must be inserted beneath the endoscope and outside of

the platform passageway. This requires manually lifting the device, which can

cause injury to the target vessel and fatigue to the operator. The harvesting

devices lack a long semi-tubular hood having side walls that lends numerous

advantages to the present invention.

Applicant has devised an apparatus that avoids many of the disadvantages

of known methods. Applicant attaches a self-supporting, full-length semi-tubular hood to the shaft containing the endoscope. The hood provides easy access to

any subcutaneous site while elevating the downward looking endoscope above and

away from tissues so that it is less commonly soiled, thereby avoiding periodic

cleaning of the endoscopic lens. Various instruments, such as endo-scissors, endo-

staplers, retractors or dissectors, may be easily inserted within the semi-tubular

hood during harvesting without withdrawing the entire device.

SUMMARY OF THE INVENTION

Applicant has devised an apparatus for removing vessels and arteries from

the patient with minimally invasive procedures. The apparatus has a self-

retaining, full-length semi-tubular hood attached to a shaft that is inserted into a

small incision through the skin to provide and maintain a generous work space and

permits the easy insertion and use of a variety of surgical instruments

simultaneously, e.g., a dissector and retractor.

Accordingly, it is an object of the present invention to provide an

improved endoscopic device, especially useful for dissecting veins or arteries.

It is a further object of the present invention to provide an endoscopic

device that permits the passage therethrough and maneuverability therein of

multiple instruments. It is a further object of the present invention to provide an endoscopic

device that permits more downward viewing of the target tissues, with less

frequent need for retraction and cleaning of the endoscope.

It is a further object of the present invention to provide an endoscopic

device for dissecting veins or arteries that minimizes damage to the target tissues.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 A schematically illustrates a side view of the device of the present

invention, with handle and semi-tubular hood.

Figure IB schematically illustrates a bottom view of the device of the

present invention.

Figure 1C schematically illustrates a cross-section of the device of the

present invention.

Figure 2 schematically illustrates a top view of the device of the present

invention.

Figure 3 schematically illustrates a surgeon in the process of inserting the

device of the invention through an incision of the patient's leg.

Figure 4 schematically illustrates an enlarged perspective view of the distal

end of the tool placed over an exposed vessel.

Figure 5 schematically illustrates the perspective view of Figure 4 with

endo-scissors and dissector placed together to work within view of the endoscope. Figure 6 schematically illustrates a side elevation of the tool tip showing

phantom lines for the field of endoscopic vision of the enlarged work space.

Figure 7 schematically illustrates a bottom plan view of the tool tip of

Figure 6.

Figure 8 schematically illustrates a transverse cross-section taken along the

lines 8-8 in Figure 6, with (stippled) fat encompassing the tool.

DETAILED DESCRIPTION OF THE INVENTION

The device of the present invention allows a generous working space for

endoscopic surgery, for example dissection and retraction of blood vessels, e.g.,

the saphenous vein for vessel harvesting. One embodiment of the device of the

present invention is set forth by way of example in Figures 1A, IB and lC.

Figure 1 A is a side view of device 8 showing a shaft 2 attached to a semi-tubular

hood 3 and opening 4 for insertion (beginning with tip 5) into the subcutaneous

space after incision of the skin over the vessel to be removed. Figure 1 A lacks an

endoscope. However, any endoscope, as shown as 18 in Figure 4, may be inserted

into the shaft 2 (or even through the semi-tubular hood 3) for viewing further

surgical manipulations taking place beneath the opening 4, including dissection,

ligation, stapling and retraction. An optional handle 1 provides convenient manual

positioning by the surgeon, the endoscope fiber optic wire (shown as 19 in Figure

3) protruding out of the top 6 of the handle. A bottom view of the device 8 of the present invention is schematically illustrated, in one embodiment of the present

invention, as Figure IB. The bottom is supported by the side walls of the semi-

tubular hood and is otherwise open.

The semi-tubular hood preferably extends over the full length of the

endoscope shaft, or at least the length thereof that is to be inserted into the

patient. The side walls of the semi-tubular hood 3 support the top and retain the

generous working space without requiring application of external force to insert

auxiliary instruments therein. By a generous working space within the semi-

tubular hood is meant that at least one, or preferably at least two, separate

instruments can be inserted therein simultaneously with the endoscope in place.

For example, a retractor and an excisor will preferably fit within the semi-tubular

hood area, and the target tissues can be viewed with the endoscope while work is

being performed. A cross-sectional view of the device 8 of the present invention

is schematically illustrated in Figure 1C, showing such a generous working space,

without the auxiliary instruments therein.

The semi-tubular hood 3 support thus creates a tunnel space for

the insertion and removal of instruments to assist in the dissection of veins and

arteries. Preferably, the top wall of the semi-tubular hood has an arc of greater

than 120°, more preferably greater than 150°, and most preferably about 180°

across the top. The side walls may extend in a downward direction from the arc to

a length varying depending upon the length and depth of the vessels to be removed and the relative size of the patient. The side walls terminate in smooth, rounded

bottom edges so as to be atraumatic to the adjacent tissues. The dimensions of the

side walls varies according to the length and depth of the vessel to be removed, the

size of the patient, and the relative obesity of the patient. The height of the side

walls, excluding the added height from the top wall (at least about 0.5 cm), varies

between about 0.5 cm and about 7.5 cm, preferably between about 1.5 cm and

about 3.0 cm, most preferably about 2.5 cm. For obese patients, the preferred

height of the side walls is greater, i.e., between about 2.5 cm and about 5.0 cm.

A top view of one embodiment of the device of the present invention is set

forth in Figure 2, showing semi-tubular hood 3, handle 1, shaft 2, and concave head

as device tip 5. A hatched area 7 secures the cord for the endoscope, and is

typically made of rubber.

A surgeon is shown in Figure 3 inserting the device 8 of the present

invention through an incision 13 in the skin of the patient's leg 9. The semi-

tubular hood 3, power source 10, and endoscopic fiber optic wire 19 are shown. It

is readily apparent from this figure that the size of the device 8 will depend on the

size and location of the blood vessel to be removed, as well as the relative obesity

of the patient. The entire arrangement permits a two-handed procedure, unlike

known protocols in the art, because the semi-tubular hood maintains the working

space along the length of the endoscope. Figure 4 schematically illustrates, in one embodiment of the present

invention, an enlarged perspective view of the distal end of the device placed over

an exposed vessel. The downward looking scope 12 is shown immediately over

the working area defined by phantom lines 11 in the field of endoscopic vision.

This embodiment also shows that the shaft 2 is placed on top of the semi-tubular

hood 3, but other embodiments include a shaft placed inside of the semi-tubular

hood, e.g., attached to the inside and the top of the semi-tubular hood. The

generous working space beneath the semi-tubular hood 3 and over the exposed

blood vessel provides many practical advantages in surgical procedure.

Figure 5 schematically illustrates, in one embodiment of the present

invention, an enlarged perspective view of the distal end of the device, placed over

an exposed vessel, as in Figure 4, but with dissector 14 and endo-scissors 15

shown inserted and placed in the work space of the device. The dissector here is a

disposable rod with a spool of fibrous material at the end for wrapping and

withdrawal of the dissected vessel. Endo-scissors 15 here are a disposable rod

with a small pair of sheers at the terminal end embracing a blood vessel to be cut.

Also shown are the shaft 2, semi-tubular hood 3, the endoscope 18 and its

downward looking scope 12 and blood vessel 16 to be harvested. It is readily

apparent that a variety of other instruments can be inserted into the working space

under the semi-tubular hood 3. For example, retractors, endo-staplers, suction

devices, electric or ultrasonic cantory devices, blowers, as well as various other types of dissectors can be inserted without withdrawing the entire device from the

underneath the skin of the patient.

Figure 6 schematically illustrates, in one embodiment of the present

invention, a side elevation of the device tip, showing phantom lines 11 for the field

ofendoscopic vision of an enlarged workspace. The downward looking scope 12

and exposed blood vessel 16 are also shown.

Figure 7 schematically illustrates, in one embodiment of the present

invention, a bottom plan view of the tool tip of Figure 6. The downward looking

scope 12 with phantom lines 11 for the field of endoscopic vision are shown. In

one embodiment, the leading edge of the tip or spoon has an indentation 20 to

accommodate the curvature of the vessel being harvested.

Figure 8 schematically illustrates, in one embodiment of the present

invention, a transverse cross-section taken at 8-8 of Figure 6, when the device is

inserted under the skin of a patient's leg. Also illustrated are the semi-tubular

hood 3, downward looking scope 12, exposed blood vessel 16, and fat 17 shown

as stippling.

The semi-tubular hood 3 is preferably made of transparent plastic, or

stainless steel. Preferably, it is made of transparent plastic, making it less costly.

A steel strut may be inserted into the shaft 2 or the back of the semi-tubular hood

3 to minimize bending or other deformation of the device during use. The dimensions of the semi-tubular hood 3 vary according to the length

and depth of the vessel to be removed, the size of the patient, and the relative

obesity of the patient. The height of the semi-tubular hood 3, excludingthe added

height from the attached shaft (about 0.5 cm), varies between about 1.5 cm and

about 5.0 cm, preferably between about 2.0 cm and about 3.0 cm, most preferably

about 2.5 cm. For obese patients, the preferred height of the semi-tubular hood 3

is greater, i.e., between about 3.0 cm and about 5.0 cm.

The semi-tubular hood 3 is attached to the length of the shaft 2, but need

not have the same length as the shaft 2. The length of the semi-tubular hood 3

(excluding the spoon at the tip 5, about 5 cm) may vary between about 15 cm and

about 45 cm, preferably between about 20 cm and about 31 cm, most preferably

about 25 cm. The shaft 2 need not be attached on top and outside of the semi-

tubular hood 3, but instead may be attached to the top of the inside of the semi-

tubular hood 3. The preferred arrangement is a shaft attachment to the top and

outside of the semi-tubular hood 3, to increase the size of the access to the work

space beneath the downward looking endoscope 12.

The width of the semi-tubular hood 3 is the breadth across the bottom of

the semi-tubular hood 3 on the side opposite to the side of the semi-tubular hood

3 with the endoscope 18 and attached shaft 2. The width may vary according to

the length of vessel to be removed, and the size and relative obesity of the patient.

Width may vary between about 2.0 cm and about 5.0 cm, preferably between about 2.0 cm to about 3.0 cm. For obese patients, a greater width is typically

desirable, e.g., between about 2.0 cm and about 4.0 cm. Furthermore, the width

may vary in a single device, such that the semi-tubular hood 3 tapers in width.

The shaft 2 houses the endoscope, and should be big enough to only

snugly fit the endoscope 18 without rattling. The shaft 2 is not completely in the

working space of the semi-tubular hood, but rather lies in the wall or above the

wall of the semi-tubular hood. A device 8 with the appropriate shaft inner

diameter is selected for the appropriate endoscope. The inner diameter of the

shaft 2 will vary according to the size of the endoscope 18, and may range

between about 2 mm and about 5 mm. Typical endoscopes currently in use are

fiber optic quartz rods of about 30 cm in length, with about 5 mm in diameter.

Other endoscopes are cables with substantially smaller diameter, e.g., about 2 mm.

The device of the present invention is adaptable to various types of endoscopes,

and fashioning the correct shaft dimensions of the device is within the skill of the

art. Endoscopes with a downward looking scope 12 with an angle of between

about 0° and about 90° are preferred, more preferred are endoscopes with a

downward looking scope 12 with an angle of between about 30° and about 60°,

and most preferred are endoscopes with a downward looking scope 12 with an

angle of between about 45 The invention is able to utilize an endoscope with a

greater downward looking angle than prior similar instruments, due to the increase

in depth of working space within the semi-tubular hood. This configuration permits the endoscope to remain more clear of debris, minimizing the number of

withdrawals for cleaning during a procedure.

In the techniques of the present invention, an incision in the skin of about

3-4 cm in length is made in the patient's leg near the identified vessel. Device 8 is

inserted along and above the vessel 13 to be harvested. A dissector, e.g., 14, is

then inserted through the incision and tissue is then dissected away from the

superior surface of the vessel as the dissector is manipulated along the surface of

the vessel under direct visualization.

After the initial dissection of the superior surface of the vessel by the

dissector, the dissector may be withdrawn and replaced with a retractor which is

also inserted through the incision and advanced under the semi-tubular hood.

Alternatively, the dissector may remain under the semi-tubular hood. At this

point, endo-scissors may be inserted, as shown in Figure 5, or any other

appropriate instrument, including a retractor, and endo-stapler, a suction or

cautery apparatus, or blower device. In the process of removing or harvesting a

blood vessel, side branches of the vessel are dissected, ligated and transected

within the working space provided by the device of the present invention. After

transection of the proximal and distal ends of the vessel, the vessel may be

removed through the incision and can be used in a bypass or grafting procedure.

In one preferred embodiment of the present invention, the device 8 can

function as both a dissector and a retractor, thus eliminating the need for two devices, i.e., an endoscopic dissector and an endoscopic retractor. The device 8 of

the present invention accommodates an endoscope 18 with a downward looking

scope 12 with an angle of between about 0° and about 90°, preferably between

about 30° and about 60°, most preferably 45°. Such an increased downward

looking angle permits the endoscope to remain relatively more clear of debris

during the procedure, which thus permits less frequent withdrawal and cleaning of

the endoscope.

It is apparent that the endoscopic device of the present invention can be

used in a variety of surgical procedures in addition to blood vessel harvesting, such

as peripheral vascular surgery, excision of subcutaneous masses including

lymphomas, or in situ saphenous vein by-pass grafting for peripheral vascular

disease, for example.

While the foregoing specification teaches the principles of the present

invention, with examples provided for the purpose of illustration, it will be

understood that the practice of the invention encompasses all of the usual

variations, adaptations, and modifications, as come within the scope of the

following claims and its equivalents.

Claims

1. An endoscopic device, comprising:

a. a shaft having a lumen therethrough for receiving an endoscope;

b. a semi-tubular hood having an arched top wall connected to the

shaft and self-supporting side walls extending downward from the arched

top wall, wherein the semi-tubular hood permits the separation of layers of

tissue during dissection and maintains a generous working space capable of

receiving at least one additional surgical instrument therein; and,

c. a concave head connected to a distal end of the semi-tubular hood,

the head having a spoon-shape and defining a cavity thereunder.

2. The device of Claim 1 , further comprising a handle connected to the shaft or to

the semi-tubular hood at the proximal end of the shaft or semi-tubular hood.

3. The device of Claim 1, wherein the endoscope has a downward looking scope

at an angle of between about 30┬░ and about 60┬░.

4. The device of Claim 1, wherein the endoscope has a downward looking scope

at an angle of about 45┬░.

5. The device of Claim 1, wherein the spoon-shaped head has an indentation at

its leading edge to accommodate a vessel to be harvested.

6. The device of Claim 1, wherein the semi-tubular hood extends the full length of

the endoscopic shaft.

7. The device of Claim 1, wherein the endoscope shaft is in or above the top wall

of the semi-tubular hood, thereby not impinging on the working space within

the semi-tubular hood.

8. The device of Claim 1, wherein the top wall of the semi-tubular hood has an

arc of greater than 120┬░.

9. The device of Claim 1 , wherein the top wall of the semi-tubular hood has an

arc of about 180┬░.

10. The device of Claim 1, wherein the side walls extend downward from the top

arched wall for a length of between about 0.5 cm to about 7.5 cm.