Valvulotome and method of using

A valvulotome for disrupting vein valves in in-situ procedures, and for distrupting the vein valves in vein segments to be used in CABG procedures. The valvulotome includes an elongate blade mounting member and a thin, scythe-shaped cutting blade. The cutting blade is mounted relative to the blade mounting member such that the plane defined by the blade lies on the axis defined by the blade mounting member. The cutting blade has a fixed end, a free end, a cutting edge and a blunt back edge. The fixed end is fixedly attached to a distal portion of the blade mounting member. The sharpened edge faces towards the blade mounting member, which protects the vein from the sharpened edge. The sharpened edge arcs outwards and proximally from the distal portion of the blade mounting member, and terminates in a proximal portion, spaced from the blade mounting member. The blunt back edge is opposite the sharpened edge, facing the vein. The free end is opposite the fixed end and connects the blunt back edge to the proximal portion of the sharpened edge. The free end including a blunt proximal-facing portion that forms a continuation of the blunt back edge.

FIELD OF THE INVENTION 
The present invention relates to a vein valve cutter (also called a 
valvulotome) for use in disrupting venous valves during vascular 
reconstructive surgery. In particular, the invention relates to apparatus 
for disrupting venous valves in vein segments for use in coronary artery 
bypass graft (CABG) procedures, and also for use in in situ bypass 
procedures, and to methods of using the apparatus to disrupt vein valves 
in such procedures. 
BACKGROUND OF THE INVENTION 
In CABG procedures, occlusive disease in the coronary arteries is routinely 
bypassed with segments of saphenous vein removed from the leg. It is 
advantageous to place the saphenous vein used as the bypass conduit in the 
non-reversed orientation. For the saphenous vein to be used in the 
nonreversed orientation, the valves of the vein must be rendered 
incompetent. Even if the saphenous vein is used in the reversed 
orientation, the valves of the vein must be rendered incompetent, since 
competent valve leaflets can be a site for future clot formation behind 
the leaflet, which can compromise the viability of the graft. 
In in situ bypass procedures, occlusive disease in the arterial system of 
the leg is bypassed with a segment of adjacent saphenous vein left 
undissected from the surrounding tissue. For blood to flow in its new 
direction, the valves in the saphenous vein segment must be obliterated. 
In this procedure, it is often desirable to view the valve-cutting process 
directly using a fiber optic scope inserted into the vein. 
In both the CABG and the in situ procedures, an infusion of physiologic 
solution into the vein is useful to identify the valve by clearing the 
field of view and temporarily closing the valves. 
Previous efforts to disrupt the valves within a vein have led to a number 
of devices and techniques. 
One form of valvulotome, called a Mills valvulotome, consists of a long, 
thin shaft with a short, narrow blade at its distal end. The blade is 
approximately perpendicular to the longitudinal axis of the shaft. The end 
of the blade remote from the shaft has a small spherical tip. The blade 
has a cutting edge along substantially all of its proximal edge, while the 
distal edge is dull. 
A significant shortcoming of the L-shaped design of the Mills valvulotome 
is the propensity for the blade to snag on side branches of the saphenous 
vein. This tendency is both cumbersome for the surgeon and also can 
compromise the integrity of the vein graft. The blade of the Mills 
valvulotome is small enough to enter side branches easily and, once 
engaged within the branch, can cut the wall of the vein. 
Another type of valvulotome design consists of a wire with a large 
bullet-shaped tip and round guide pulled by a catheter. The cutting 
element is located at the proximal end of the bullet tip. Valvulotomes of 
this design include the LeMaitre, Leather, Hall and Insitucat styles. This 
design is less prone to catching in side branches but has the 
disadvantages of being bulky, incompatible with angioscopy for 
visualization of the cutting-process, and is effective only over a narrow 
range of vein diameters. Also, the Leather, Hall and Insitucat designs 
require proper rotational orientation to align properly with the valve 
cusps, a requirement that is difficult to achieve, given their 
incompatibility with fiber optic viewing. Moreover, devices of this design 
tend to tear the valve instead of cut it because the cutting force is 
simultaneously applied to a relatively large area of the valve. 
In another valvulotome design, the valve is cut by a plurality of blunt 
fingers extending from the end of a catheter. The cutter fingers are 
shielded except when exposed by the user to engage the valve. A fiber 
optic viewer extends up the center bore of the catheter to directly 
observe the cutting process. In this design, the fiber optics are an 
integral pan of the valvulotome. This design, with its many moving parts, 
has the disadvantage of being difficult to manufacture. Moreover, the 
fingers' bluntness, as well as their plurality, tend to rip the valve in a 
random manner, leaving the vein wall in an unpredictable condition. 
OBJECTS AND SUMMARY OF THE INVENTION 
Therefore, it is an object of the present invention to produce a 
valvulotome that simplifies the operation of disrupting the valves in a 
vein; reduces the tendency to snag side branches, yet easily engages and 
aligns with the valves to be cut; and truly cuts the valve neatly. 
It is also an object of the present invention to provide a version of the 
valvulotome that is capable of providing fluid irrigation. 
It is a further object of the invention to provide a valvulotome that can 
be used either with, or without direct visualization, and that is 
inherently simple to manufacture. 
Accordingly, the invention provides a valvulotome that comprises an 
elongate blade mounting member and a thin, scythe-shaped cutting blade. 
The cutting blade is mounted relative to the blade mounting member such 
that the plane defined by the blade lies on the axis defined by the blade 
mounting member. The cutting blade has a fixed end, a free end, a cutting 
edge and a blunt back edge. The fixed end is fixedly attached to a distal 
portion of the blade mounting member. The sharpened edge faces towards the 
blade mounting member, which protects the vein from the sharpened edge. 
The sharpened edge arcs outwards and proximally from the distal portion of 
the blade mounting member, and terminates in a proximal portion, spaced 
from the blade mounting member. The blunt back edge is opposite the 
sharpened edge, facing the vein. The free end is opposite the fixed end 
and connects the blunt back edge to the proximal portion of the sharpened 
edge. The free end including a blunt proximal-facing portion that forms a 
continuation of the blunt back edge. 
A portion of the blade mounting member, proximal of the distal portion, may 
be shaped to provide a blade recess accommodating the sharpened edge and 
the free end of the cutting blade. The blade recess further protects the 
vein from the sharpened edge and the sharp part of the free end of the 
cutting blade. 
The blade recess may include a proximal portion shaped to provide a 
shoulder adjacent, and spaced from, the free end of the cutting blade to 
provide yet further protection for the vein. 
The valvulotome may also include an extendable device, such as an 
extendable guide wire, that selectively moves the cutting blade laterally 
in the vein to assist the proximal end of the cutting blade to enter the 
valve pocket, prior to cutting the valve. The extension of the extendable 
device is adjustable to enable the valvulotome to be used in veins of 
different diameters, or to accommodate the change in diameter that occurs 
along the length of a single vein. 
The blade mounting member may comprise an elongate shaft and an extension 
extending distally from the distal portion of the shaft in a laterally 
offset relation to the shaft. The extension would include a distal portion 
to which the fixed end of the cutting blade is attached. 
Alternatively, the blade mounting member may comprise an elongate shaft and 
a substantially cylindrical haft extending distally from the distal 
portion of the shaft. The haft would include a blunt nose remote from the 
elongate shaft, a curved surface, a blade recess formed in the curved 
surface, and a distal portion to which the fixed end of the cutting blade 
is attached with the cutting edge and the free end in the blade recess. 
The invention also provides a valvulotome comprising an elongate shaft, a 
substantially cylindrical, blunt-nosed haft, a thin, scythe-shaped cutting 
blade, a guide wire, and a device for selectively extending an extending 
portion of the guide wire. The haft includes a distal portion, a curved 
surface, a blade recess formed in the curved surface, and a bore 
communicating with a slot formed in a portion of the curved surface 
opposite the blade recess. The cutting blade is mounted relative to the 
haft such that the plane defined by the cutting blade is on the axis 
defined by the shaft. 
The cutting blade includes a fixed end, a free end, a sharpened edge and a 
blunt back edge. The fixed end is fixedly attached to the distal portion 
of the haft. The sharpened edge faces into the blade recess, arcs outwards 
and proximally from the distal portion of the blade mounting member, and 
terminates in a proximal portion spaced from the haft and accommodated by 
the blade recess. The blunt back edge is opposite the sharpened edge, 
facing the vein. The free end is opposite the fixed end, and connects the 
blunt back edge to the proximal portion of the sharpened edge. The free 
end includes a blunt proximal-facing portion forming a continuation of the 
blunt back edge. 
The guide wire is slidably mounted in the bore, and includes an extending 
portion adjacent the slot. The device for selectively extending the 
extending portion of the guide wire selectively slides a proximal portion 
of the guide wire relative to the bore, which selectively extends the 
extending portion of the guide wire from the slot. 
The valvulotome presents to the wall of the vein two relatively large, 
blunt surfaces: to one side, the back edge of the blade; and, to the other 
side, the back of the blade mounting member. The dimensions of the 
surfaces that the valvulotome presents to the wall of the vein are larger 
than the diameter of the entries of side branches of the vein, which makes 
the valvulotome automatically reject entry into such side branches. 
Moreover, the broad, blunt surfaces of the valvulotome significantly 
reduce the possibility of the valvulotome penetrating the wall of the vein 
compared with known valvulotomes. Finally, the cutting edge of the blade 
of the valvulotome is shielded by the blade mounting member. Therefore, 
the valvulotome may be allowed to make contact with the walls of the vein 
since there is minimal risk of the valvulotome damaging the vein. This 
allows the valvulotome to be self guiding as it is advanced up the vein, 
and enables the surgeon to use the valvulotome without internal 
observation. 
Finally, the invention provides a method of performing a valvotomy. A 
valvulotome is provided that includes an elongate blade mounting member 
and a thin, scythe-shaped cutting blade. The cutting blade is mounted 
relative to the blade mounting member such that the plane defined by the 
blade lies on the axis defined by the blade mounting member. The cutting 
blade has a fixed end, a free end, a cutting edge and a blunt back edge. 
The fixed end is fixedly attached to a distal portion of the blade 
mounting member. The sharpened edge faces towards the blade mounting 
member, which protects the vein from the sharpened edge. The sharpened 
edge arcs outwards and proximally from the distal portion of the blade 
mounting member, and terminates in a proximal portion, spaced from the 
blade mounting member. The blunt back edge is opposite the sharpened edge, 
facing the vein. The free end is opposite the fixed end and connects the 
blunt back edge to the proximal portion of the sharpened edge. The free 
end including a blunt proximal-facing portion that forms a continuation of 
the blunt back edge. 
The cutting blade is moved towards the valve to automatically locate the 
free end of the cutting blade at the apex. The leaflet is pierced at the 
apex using the free end of the cutting blade. Finally, a tensile force is 
applied between the cutting blade and the leaflet to cut the leaflet from 
the apex to the edge. 
The valvulotome may additionally include an extendable guide wire mounted 
on a side of the blade mounting member remote from the cutting blade. The 
extendable guide wire is in a retracted state. Then, the step of moving 
the cutting blade towards the valve to automatically locate the proximal 
end of the cutting blade at the apex would include the step of selectively 
extending the extendable guide wire to an extended state to move the 
cutting blade laterally in the vein. This enables the free end of the 
cutting blade to enter the valve pocket easily. 
When the cutting blade is moved towards the valve, the blade mounting 
member is moved until the free end of the cutting blade contacts the 
leaflet, and advances along the leaflet to the apex. When the leaflet is 
pierced, the blade mounting member is further moved until the free end 
pierces the leaflet at a point. Finally, when a tensile force is applied 
between the cutting blade and the leaflet to cut the leaflet, the blade 
mounting member is withdrawn yet further to pull the cutting edge of the 
cutting blade through the leaflet from the point where the leaflet was 
pierced to the edge of the leaflet. 
The apex of the valve pocket corresponds to the center of the leaflet and 
is most proximal, and the method cuts the leaflet substantially along the 
center of the leaflet. When the cutting blade is moved towards the valve, 
the valvulotome is allowed to rotate axially to locate the free end of the 
cutting blade in the apex of the valve pocket. 
The valvulotome may include a traction point and be advanced through the 
vein using a suture. When the cutting blade is moved towards the valve, a 
suture is provided and is advanced through the vein. The suture is 
attached to the traction point, and the suture is drawn on to pull the 
valvulotome through the vein until the cutting blade has passed through 
the valve. Finally, the blade mounting member is withdrawn to move the 
cutting blade towards the valve. 
When the cutting blade is moved towards the valve, the vein may be gripped 
adjacent its distal end to seal the vein. The valvulotome is then advanced 
through the vein to a point adjacent the distal end and a fluid is emitted 
from the valvulotome to inflate the part of the vein between the distal 
end and the valve. The position of the valve in the vein is then 
determined by observing the inflated part of the vein. 
The method may additionally comprise the step of emitting fluid from the 
valvulotome to impinge on the leaflet adjacent to the cutting blade to 
displace the leaflet away from the vein, prior to moving the cutting blade 
towards the valve. 
The method may be performed by a surgeon without assistance. Prior to 
moving the cutting blade towards the valve, the surgeon holds the proximal 
end of the vein in his/her first hand and holds the blade mounting member 
in his/her second hand. The surgeon inserts the cutting blade into the 
proximal end of the vein, and advances the cutting blade through the 
valve. The surgeon then moves his/her first hand to grip and seal the 
distal end of the vein. Then, with his/her second hand, the surgeon causes 
the valvulotome to emit fluid which inflates the vein. When the cutting 
blade is moved towards the valve, surgeon withdraws the blade mounting 
member using his/her the second hand.

DETAILED DESCRIPTION OF THE INVENTION 
FIG. 1 shows a first embodiment of the valvulotome 1 according to the 
invention in position in a vein V. The valvulotome 1 is shown with its 
blade 11 in position in the valve pocket P1, about to pierce the apex of 
the leaflet L1. The vein V, normally a saphenous vein, but the valvulotome 
can be used in other veins, includes a valve Val comprising two leaflets, 
a first leaflet L1 and a second leaflet L2. On the distal side of the 
valve Val, i.e., on the side closer to the heart, is a side branch B1. 
More proximal on the vein is a second valve Va2 with a second side branch 
B2 on its distal side. When the vein is in the leg, blood flows in the 
vein in the direction indicated by the arrow BF. This will be called the 
"normal direction". 
The valvulotome 1 is shown in detail in FIG. 2. The shaft 6 is preferably 
made from a piece of no. 19 stainless steel tubing with an outside 
diameter of about 0.042" (1.1 mm), an internal diameter of 0.027"(0.7 mm), 
and a length of about 10.5" (265 mm). Making the shaft from stainless 
steel tubing provides a rigid valvulotome preferable for use in CABG 
procedures. The shaft 6 may also be made flexible so that the valvulotome 
can be used in in-situ bypass procedures. In this case, the preferred 
material for the shaft is ABS tubing (a terpolymer of acrylonitrile, 
butadiene and styrene) with the same internal diameter as no. 19 stainless 
steel tubing, and a somewhat larger outside diameter. 
A plastic female luer hub 21 is attached with glue to the proximal end of 
the shaft 6. The extension 51 is laterally displaced from the shaft 6 to 
provide a blade recess 46 in which the blade 11 fits such that the blunt 
back side 102 of the blade is substantially coaxial with the shaft 6. With 
this arrangement, the shoulder between the shaft 6 and the extension 51 
protects the vein wall from the proximal end 117 of the blade, which is 
sharpened over part of its circumference. 
The extension 51 is preferably formed from the same piece of no. 19 
stainless steel tubing as is used for the shaft 6. If an ABS shaft used, a 
separate stainless steel extension is formed which is then attached to the 
shaft. Preferably, the extension 51 is formed by making three 
approximately 45.degree. degree bends 61, 66, and 71 in the stainless 
steel tubing. Between the bends are three substantially straight sections. 
Between the bends 61 and 66 is a first, short, section 76. Between the 
bends 66 and 71 is a second, longer, section 81 that is substantially 
parallel to the shaft 6. Between the bend 71 and the distal end of the 
extension 51 is a third, short section 86 that is substantially 
perpendicular to the first section 76. Bends 61 and 66 may merge into one 
another and, as a result, the first section 76 may lack any discernable 
straight part. The third bend 71 is made such that the distal end of the 
section 86 is substantially in line with the longitudinal axis of the 
shaft 6. Preferably, the extension 51 is about 0.7" (18 mm) long and 
0.15"(3.8 mm) offset. 
The extension 51 may be formed differently from the way just described: for 
example, it can have a continuous curve instead of three discrete bends. 
Alternatively, the third bend 71 and third section 86 can be dispensed 
with, and the blade 11 can be attached to the distal end of the second 
section 81. In this alternative, the shape of the blade 11 is changed to 
enable it to be attached to the second section 81 instead of the third 
section 86, but the distal end of the blade 11 provides substantially the 
same profile for the distal end of the valvulotome 1 as that shown in FIG. 
2. 
Details of the blade 11 are shown in FIG. 3A. The blade 11 is preferably 
made from stainless steel about 0.008" (0.2 mm) thick, and is preferably 
photo etched to the profile shown in FIG. 3A. The back 102 of the blade is 
substantially straight over most of its length. The proximal part of the 
back of the blade indicated by the numeral 107 is curved into the blade 
recess 46. The curved part 107 of the back of the blade is also curved 
into the blade recess 46 so that the shoulder between the shaft 6 and the 
extension 51 can reduce the possibility of the proximal end 127 of the 
blade from snagging the wall of the vein or entering a side branch when 
the valvulotome is withdrawn. The curved part 107 of the back of the blade 
is also curved to enable the proximal end 127 of the blade to seat more 
deeply in the valve pocket when the walls of the vein near the valve am 
inflated by fluid pressure. The similarity between the curvature of the 
curved part 107 of the blade and the curvature of the inflated wall of the 
vein can be seen in FIG. 4A. The back 102 of the blade is radiused and 
deburred, and hence is blunt, as shown in FIG. 3B, to minimize the 
possibility of it damaging the vein wall. 
Alternatively, the blade could be provided with a back 102A that is 
substantially thicker (about 0.065"-1.65 mm) than the rest of the blade, 
as shown in FIG. 3C. This will further reduce the possibility of damaging 
the vein wall. Additionally, the thicker back 102A is easier to see 
through the vein wall. The blade could be provided with the thicker back 
102A by rolling or bending the back portion of the blade relative to the 
rest of the blade. Alternatively, the thicker back could be provided by 
injection molding as part of the bead 157. 
The cutting edge 112 of the blade is opposite the back 102 of the blade, is 
preferably curved as shown in FIG. 3A, and is ground to give it a sharp 
edge between the extremities indicated by the numerals 117 and 122. The 
curved shape of the cutting edge 112 enables the cutting edge to cut the 
valve leaflet effectively while minimizing the possibility of the cutting 
edge accidentally damaging the vein. The curvature of the cutting edge 112 
substantially matches the curvature of the curved part 107 of the back of 
the blade. This enables the proximal end 127 of the blade to have a 
relatively large radius instead of a point that would be more likely to 
damage the vein accidentally. The blade 11 broadens towards its distal 
end, which enables the cutting edge 112 to cut the leaflet all the way to 
the edge of the leaflet while maintaining the back 102 of the blade in 
contact with the wall of the vein. 
As already mentioned, the proximal end 127 of the blade 11 is relatively 
broad and is radiused across its width. Like the back 102 of the blade, 
the proximal end 127 is deburred and radiused across its thickness and is 
therefore blunt to minimize the possibility of it accidentally damaging 
the vein when the valvulotome 1 is withdrawn. The proximal end 127 of the 
blade pierces the pocket of the valve during the cutting process, but is 
only able to pierce when working against the relatively high resistance 
provided by the leaflet (e.g., L1, L2) close to its apex (e.g., P1, P2). 
Other parts of the blade 11 are concerned with mounting the blade in the 
extension 51. The distal end 132 of the blade is cut at about 45 degrees 
relative to the back 102 of the blade. The angle of the distal end 132 of 
the blade relative to the back 102 must match the angle between the third 
section 86 of the extension 51 (FIG. 2) and the shaft 6. This ensures that 
the back 102 of the blade is substantially parallel to the longitudinal 
axis of the shaft 6. 
The blade 11 is preferably spot welded to one side of the third section 86 
of the extension 51 such that the second section 81 of the extension 51 
shields the cutting edge 112 of the blade, as shown in FIGS. 4A and 4B. 
The blade 11 is angled relative to the axis of the shaft 6 so that the 
proximal end of the blade 127 is in line with the axis of the shaft, as 
shown in FIG. 4B. 
Alternatively, a slot 147 can be formed in the center of the inner face of 
the distal part of the third section 86, and the distal end of the blade 
11 can be spot welded in the slot. This way, the blade is parallel to the 
axis of the shaft. 
The blade 11 is attached to the third section 86 of the extension 51 such 
that the distal end of the back 102 of the blade is flush with the distal 
end of the third section 86. The blade 11 is also attached such that the 
gap between the inner part of the proximal end 127 of the blade and the 
second section 81 of the extension is preferably about 0.050" (1.2 mm). 
This distance is small enough to enable the second section 81 to 
effectively shield the cutting edge 112 of the blade, yet is large enough 
to admit the thickest part of the leaflet for cutting. 
The blade 11 preferably also includes the blade extension 152 on which is 
mounted the tip 157. The tip 157 provides the valvulotome 1 with a very 
dull nose. Providing the valvulotome 1 with a very dull nose ensures that 
the valvulotome 1 has a minimal ability to pierce as it is advanced 
through the vein, and thus minimizes the possibility of the valvulotome 
damaging the vein. FIGS. 4A, 4B, and 6 show a substantially spheroidal tip 
157 of metal or plastic. The tip 157 is preferably injection molded 
directly around the blade extension 152. Alternatively, a molded tip 157 
can be secured in place by a suitable adhesive, such as an epoxy adhesive, 
or the tip can be a press fit, secured by the tabs 167. 
An alternative to the spheroidal tip 157 is shown in FIG. 7 in which a 
flexible tip 172 is attached to the blade extension 152. The flexible tip 
172 is a hollow cylindrical piece of a flexible silicone plastic and is 
attached to the blade extension 152 by a suitable adhesive, such as an RTV 
silicone adhesive, or alternatively is a push fit on the blade extension 
152, secured by the tabs 167 (FIG. 3A). The flexible tip 172 is not only 
very dull like the spheroidal tip 157, but is also soft, which further 
reduces the possibility of damaging the vein when the valvulotome 1 is 
advanced. 
The blade extension 152 may be dispensed with and a suitable tip be mounted 
on the end of the third section 86 (FIG. 2). Alternatively, the end of the 
third section 86 may be suitably flattened and shaped to provide the 
valvulotome 1 with a dull nose without the need for a separate component. 
The blade 11 may optionally include a traction point 181 positioned about 
half-way across the width of the blade and positioned along the length of 
the blade such that it is close to the extension 51, as shown in FIG. 3A. 
The traction point 181 is preferably a hole about 0.03" (0.76 mm) in 
diameter. A suture attached to the traction point 181 enables the 
valvulotome 1 to be advanced through the vein by pulling on the suture. 
The suture applies a tensile force to the valvulotome. Pulling the 
valvulotome through the vein can be used as an alternative to, or in 
addition to, pushing the valvulotome through the vein using the column 
strength of the shaft 6. 
The suture attached to the traction point 181 may be attached to a 
fiber-optic viewing scope. With this arrangement, the scope applies the 
tensile force to the valvulotome to advance the valvulotome up the vein. 
The suture maintains a fixed distance between the scope and the blade 11 
of the valvulotome, which ensures that the blade remains in the field of 
view and in the focal plane of the scope. The suture may alternatively be 
attached to a catheter. 
The dull nose, curved blade, and extension of the valvulotome according to 
the invention enable the valvulotome to be advanced and withdrawn in the 
vein with a minimum likelihood of causing damage. The valvulotome presents 
large, blunt surfaces to the walls of the valvulotome. The effective 
dimensions of the surfaces that the valvulotome according to the invention 
presents to the vein, i.e., the tip, the back of the blade, and the 
extension, are large compared with the diameter of side branches, enabling 
the valvulotome to resist entering side branches. FIG. 10 shows the 
valvulotome 1 being withdrawn to cut the valve Val. The length of the 
blade 11 is such that the blunt back 102 of the blade spans the mouth of 
the side branch SB. This prevents the blade from entering the side branch 
SB and possibly damaging the side branch SB or the vein V in the vicinity 
of the side branch SB. 
The prior art Mills valvulotome M shown in FIG. 11 presents to the vein a 
surface, namely, the surface of the tip T, the effective dimensions of 
which are comparable with the diameter of mouth of the side branch SB. 
This enables the tip T accidentally to enter the mouth of the side branch 
SB relatively easily. The tip T entering the mouth of the side branch SB 
exposes the junction of the side branch SB and the vein V to the sharp 
cutting edge X of the Mills valvulotome. If the surgeon withdraws the 
valvulotome with its tip T engaged in the side branch, the valvulotome 
will cut down the wall of the vein V and render the vein unusable. 
The arrangements for providing irrigation and inflation are shown in FIGS. 
1, 4A, and 4B. The purpose of inflating the vein is to enable the location 
of the valves in the vein to be determined. Additionally, inflation closes 
the valve tightly around the shaft of the valvulotome 1, and retracts the 
valve away from the vein wall, improving the access of the proximal end 
127 of the blade to the valve pocket P1. 
In FIG. 1, the proximal end of the shaft 6 is attached to the plastic luer 
hub 21, onto which is screwed a standard 5 ml plastic syringe 26. The 
syringe 26 holds a supply of physiologic solution 31, or some other 
suitable fluid, and provides a means for pumping the solution 31 up to the 
valvulotome 1 for inflating the vein and displacing the leaflets L1 and 
L2. In an alternative embodiment, the length of the shaft 6 of the 
valvulotome is reduced to about 2.5" (65 mm), and the effective length of 
the valvulotome 1 is restored by attaching it to the distal end of a 
hollow stainless steel rod about 12" (305 mm) long. A luer hub, to which a 
syringe can be attached, is a push fit on the proximal end of the rod. 
The valvulotome 1 can emit the physiologic solution 31 in a number of 
different ways. For instance, FIG. 4A shows a bore 174 in the third 
section 86 through which the solution is emitted in a forward direction, 
as indicated by the arrow 177. Alternatively, and preferably, valvulotome 
1 can emit the solution 31 in a retrograde direction in a number of 
different ways. Emitting solution in a retrograde direction is preferable 
because it directs the solution towards the leaflet being cut. FIG. 4A 
shows a number of retrograde emission alternatives. A practical embodiment 
emits solution in only one or two ways. If the valvulotome 1 is not to 
emit solution in the forward direction, the distal end of the third 
section of the extension must be sealed. The tip 157 or 172 can be adapted 
to provide suitable sealing. 
A slot 147 (FIG. 4B) can formed in the third section 86 of the extension 
51, adjacent to the blade. Solution emitted from the extension 51 through 
the slot 147 remains in contact with the blade 11, runs down the blade in 
a laminar flow, as indicated by the arrow 187 (FIG. 4A), and falls off the 
end of the blade into the valve pocket. Alternatively or additionally, a 
hole 192, about 0.026" (0.66 mm) in diameter, is drilled in the wall of 
the third section 86 between the bend 66 and the root of the blade 11. 
Depending on the geometry of the hole 192, the hole 192 emits solution 
towards the proximal end 127 of the blade, in a jet or in a fan-shaped 
spray, as indicated by the arrow 196. 
The direction in which the valvulotome emits solution is relatively 
unimportant when the solution is providing inflation prior to cutting the 
first leaflet L1. However, cutting the first leaflet L1 releases some 
pressure. The pressure may drop slowly enough for the valvulotome 1 to be 
advanced, rotated through 180 degrees and engaged with the second leaflet 
while there is still sufficient pressure to hold the leaflet L2 against 
the shaft of the valvulotome 1. Since the purpose of cutting the leaflet 
L1 is to prevent it holding pressure, sufficient pressure to hold the 
second leaflet L2 in place cannot be relied upon. If the pressure drops 
quickly, or if re-positioning the valvulotome is delayed, emitting 
solution towards the proximal end 127 of the blade enables the solution to 
impinge on the inner surface of the second leaflet L2 and to enter the 
valve pocket between the leaflet L2 and the vein wall. The force of the 
solution presses the leaflet L2 against the shaft of the valvulotome, and 
enables the blade to enter the valve pocket P2 to cut the second leaflet 
L2. 
FIGS. 5A through 5E show several embodiments of a pivoting blade 
valvulotome according to the invention, in which the blade is pivotally 
mounted in the extension. The pivoting blade valvulotomes further reduce 
the risk of accidentally injuring the vein, as shown in FIGS. 5A and 5B. 
FIG. 5A shows a pivoting blade valvulotome IX with its blade 11X in the 
closed position. In this position, the cutting edge is moved further into 
the blade recess 46X, closer to the extension 51X, than in the fixedblade 
valvulotome shown in FIG. 2. This enables the extension to provide an even 
greater amount of protection against the cutting edge of the blade 
accidentally cutting the vein. This also enables the shoulder between the 
shaft 6X and the extension 51X to provide an even greater amount of 
protection against the proximal end of the blade snagging the wall of the 
vein or entering a side branch. The lower profile of the pivoting blade 
valvulotomes allows them to be used in smaller veins. 
FIG. 5A shows the proximal end 117X of the blade 11X substantially 
contacting the second section 81X. The degree of protection provided by 
the second section may be further increased by providing a slot in the 
second section to accommodate the blade when the blade is in the closed 
position. 
FIG. 5B shows the pivoting blade valvulotome IX with its blade 11X swung 
out into the open position, just prior to cutting a leaflet. With the 
blade 11X in its open position, a greater clearance can be provided 
between the proximal end 117X of the blade and the second part 81X of the 
extension than in the fixed-blade valvulotome shown in FIG. 2. This makes 
it easier for the proximal end of the blade to enter the valve pocket. 
Although the embodiments of the pivoting blade valvulotome differ in 
detail, they all have closed and open positions corresponding to the 
closed and open positions shown in FIG. 5A and 5B, respectively. 
A preferred embodiment of the pivoting blade valvulotome 1A according to 
the invention is shown in FIG. 5C. The blade 11A is similar to the blade 
11 shown in FIG. 3A, except that its width is maintained substantially 
constant along its length, as shown in FIG. 5C. The back 102A of the blade 
is preferably widened, as shown in FIG. 3C. 
The distal end 114A of the blade is shaped with a section 115A, which is 
quarter-radiused about the pivot hole 116A, and a straight section 123A. 
The quarter-radiused section 115A allows the blade 11A to pivot in the 
extension 51A until the straight section 123A juxtaposes the third section 
86A. This provides a mechanical limit to the outward movement of the blade 
11A in its open position. 
The extension 51A is substantially similar to the extension 51 of FIG. 2, 
but the third section 86A is modified to accommodate the pivoting blade 
11A. A slot 124A is cut in the inside face 126A of the distal-most part of 
the third section. The slot is wide enough to accommodate the blade 11A, 
and long enough to accommodate the distal portion of the blade 11A when 
the blade is in its closed position. The slot 124A may be extended 
proximally into the second section 81A of the extension 51A to accommodate 
all of the blade 11A, and to reduce further the risk of the cutting edge 
112A of the blade 11A accidentally cutting the valve. 
The pivot pin hole, similar to the pivot pin hole 128X shown in FIG. 5A, is 
drilled through the third section 86A, is perpendicular to the slot 124A, 
and accommodates the pivot pin 120A, which also passes through the pivot 
pin hole 116A in the blade 11A. 
The valvulotome is provided with a jet hole 132A for emitting a jet of 
solution (indicated by the arrow 134A) towards the blade 11A. The jet of 
solution impinges on the blade, preferably on the widened back 102A 
thereof. Additional holes (not shown) may provide a flow of solution down 
the blade 11A. 
Preferably, the blade 11A is unbiased. The blade is moved to its closed 
position by hand before the valvulotome is inserted into the vein. 
Pressure between the vein wall and the back of the blade maintains the 
blade in its closed position as the valvulotome is advance through the 
vein. 
When the valvulotome is in position to cut a valve, the blade 11A is moved 
to its open position by a jet of solution 134A emitted by the jet hole 
132A impinging on the blade, preferably on the widened back 102A thereof. 
Once the blade has been moved to its open position, engaging the proximal 
end 117A of the blade with the valve leaflet holds the blade in its open 
position, and the flow of solution may be discontinued if desired. 
The blade may be returned to its closed position while in the vein by 
external pressure exerted through the vein wall by, for example, the 
surgeon' s finger. 
A first alternative embodiment of the pivoting blade valvulotome 1B is 
shown in FIG. 5D. In this, the blade 11B is biassed into its closed 
position by the hairspring 130B, and is pulled towards its open position 
by the operating cable 121B. 
The blade 11B and its mounting in the third section 86B of the extension is 
substantially similar to the blade 11A and its mounting just described, 
and so will not be described in detail. Corresponding parts use the same 
reference numbers with the letter "B" instead of the letter "A". 
The pivot pin 120B passes through the hairspring 130B, in addition to 
passing through the pivot pin hole 116B in the blade 11B, and the pivot 
pin hole 128B in the third section 86B. Opposite ends of the hairspring 
130B contact the blade 11B and the inner wall of the third section 86B to 
bias the blade 11B into its closed position (FIG. 5A). 
The blade 11B additionally includes the operating cable hole 119B to which 
the operating cable 121B is attached. The operating cable runs proximally 
from the blade 11B through the bore of the shaft 6B, and emerges from the 
shaft through a fluid-tight seal (not shown) near the proximal end of the 
shaft. The operating cable is preferably a stainless steel wire, about 
0.008" (0.2 mm) in diameter. The operating cable may alternatively be spot 
welded to the blade 11B. 
In use, the operating cable 121B of the alternative embodiment of the 
pivoting-blade valvulotome 1B is left slack while the valvulotome is 
advanced through the vein, as will be described in detail below. The 
hairspring 130B biases the blade 11B into its closed position shown in 
FIG. 5A. The proximity of the second section 81B to the cutting edge 112B 
of the blade ensures that the cutting edge of the blade will not 
accidentally cut the vein. 
When the extension 51B of the valvulotome is positioned just beyond the 
valve to be cut, as will be described in detail below, the surgeon applies 
tension to the operating cable 121B to move the blade 11B into its 
operating position, spaced from the second section 81B. The operating 
cable is pulled until the straight section 123B of the distal end of the 
blade 11B abuts the third section 86B, which prevents further opening of 
the blade and allows the pivoted blade to exert the force necessary to cut 
the valve. Engaging the proximal end 117B of the blade with the valve 
leaflet holds the blade 11B in its open position, and tension can be 
removed from the operating cable 121B. This enables the blade to return 
automatically to its closed position after a leaflet has been cut. The 
blade is then re-opened using the operating cable 121B when the 
valvulotome is in position to cut the next leaflet. 
In a variation on the pivoting blade valvulotome just described, the 
operating cable 121B may be dispensed with, and the blade, which would 
preferably have the widened back shown in FIG. 3C, may be moved into its 
open position by the force exerted on it by a jet of physiologic solution 
emerging from a jet hole in the inner face of the second section. This 
arrangement is similar to the arrangement in the embodiment shown in FIG. 
5C, but uses a hairspring to bias the blade into its closed position. Once 
the blade has been moved to its open position, engaging the proximal end 
of the blade with the valve leaflet holds the blade in its open position, 
and the flow of solution may be discontinued if desired. 
A second alternative embodiment 1C of a pivoting blade valvulotome 
according to the invention is shown is FIG. 5E. In this embodiment, the 
blade 11C is mounted on a spring-steel blade mount that forms part of the 
extension. The blade mount enables the blade to move as if it were pivoted 
between a closed position and an open position corresponding to the closed 
position and the open position shown in FIGS. 5A and 5B, respectively. 
Preferably, the spring-steel blade mount 130C is substituted for the third 
section and part of the second section 81C of the extension 51C. The 
second section 81C is also shaped as shown to allow the blade carrier 130C 
to attached to it, preferably by spot welding. The shaping of the second 
section 81C also provides an optimum operating angle between the operating 
cable 121C, which emerges from the second section, and the blade 11C. 
The blade carrier is preferably a piece of spring steel wire about 0.018" 
(0.42 mm) in diameter, with a shape similar to that of the third section 
and the part of the second section of the extension that it replaces. 
The blade 11C is shaped substantially the same as the blade 11 shown in 
FIG. 2, with the addition of the operating cable hole 119C. Alternatively, 
the operating cable hole can be dispensed with, and the operating cable 
can be attached to the blade by spot welding. The blade carries the soft 
tip 157C. The blade is attached to the blade carrier 130C, preferably by 
spot welding, such that it assumes its open position, as in FIG. 5C, when 
no tension is applied to the operating cable 121C. 
Applying tension to the operating cable 121C causes the blade carrier 130C 
to flex, the blade to move to its closed position, as shown for the 
embodiment shown in FIG. 5A, with the proximal end 117C of the blade close 
to the extension 51C, and the extension 51C shielding the cutting edge 
112C. 
In use, tension is applied to the operating cable 121C of the movingblade 
valvulotome 1C to move the blade to its closed position. The valvulotome 
is then advanced through the vein, as will be described in detail below. 
The proximity of the second section 81C to the cutting edge 112C of the 
blade ensures that the cutting edge will not accidentally cut the vein. 
When the extension 51C of the moving-blade valvulotome is positioned just 
beyond the valve to be cut, as will be described in detail below, the 
surgeon releases the operating cable 121C to move the blade 11C into its 
open position, spaced from the second section 81C. The valvulotome is then 
used normally, as will be described below, to cut the first leaflet of the 
valve. After the first leaflet has been cut, tension may be applied to the 
operating cable 121C again to return the blade to its closed position 
before the valvulotome is advanced up the vein to cut the second leaflet. 
When the valvulotome is in position to cut the second leaflet, tension is 
released from the operating cable to return the blade to its open position 
to cut the second leaflet. 
FIGS. 6, 7, and 8 show some of the ways in which the valvulotome according 
to the invention can be adapted to enable its rotational orientation and 
position in the vein to be observed from outside the vein. FIGS. 6 and 7 
show differential coloring, in which the extension 51 and the side of the 
tip 157 or 172 remote from the blade 11 are colored with a dark color. The 
dark color, which is shown by stippling 200 in FIGS. 6 and 7, contrasts 
with the shiny gold color of the blade 11. The contrast can be increased 
by coloring the tip 157 or 172 in a bright light color 205 on the side 
opposite to the dark-colored side. Preferred colors are black for the dark 
color and yellow for the light color. When the valvulotome is in the vein, 
the rotational orientation of the valvulotome can be determined by 
bringing the valvulotome into contact with the vein wall and observing the 
color through the vein wall. The difference between a yellow or gold part 
of the valvulotome and a black part of the valvulotome can be seen through 
the translucent wall of the vein. 
FIG. 8 shows a variation on the valvulotome 1 for use in veins that are 
insufficiently translucent for the color orientation indicators just 
described to be observed. The shaft 6 is provided with a laterally-offset 
marker in the side of the shaft opposite to the blade 11. The 
laterally-offset marker is preferably provided by the U-bend 210 in the 
shaft 6. The U-bend 210 is made by making four bends in the shaft 6. The 
parts of the shaft 6 on opposite sides of the U-bend 210 should lie on the 
same longitudinal axis. The U-bend 210 is coplanar with the extension 51 
and the blade 11, and lies on the same side of the shaft 6 as the 
extension 51. The depth d of the U-bend 210 is sightly larger than the 
diameter of the vein in which the valvulotome 1 is to be used. When the 
valvulotome 1 is inserted into the vein, the U-bend 210 causes the vein to 
flatten. The imprint of the U-bend 210 can be seen on the outside of the 
wall of the vein on one side of the vein and the imprint of the shaft 6 
can be see on the outside of the wall of the vein on the opposite side of 
the vein. This unambiguously indicates the rotational orientation of the 
valvulotome: the cutting edge 112 of the blade faces the same side of the 
vein as the side on which the imprint of the U-bend 210 can be seen. 
A further indication of the orientation of the valvulotome is provided by 
using an asymmetrical luer lock 21 (FIG. 1). The luer lock 21 can be 
provided with a flat 23. The luer lock is attached to the shaft 6 so that 
the flat 23 has a predetermined orientation relative to the blade 11. The 
preferred orientation of the flat 23 is perpendicular to the blade 11, and 
on the same side of the shaft 6 as the blade. The asymmetrical luer lock 
enables the surgeon to determine the orientation of the valvulotome in the 
vein by feeling the orientation of the flat 23 with his/her thumb or 
finger, or by observing the orientation of the flat 23. 
FIG. 9 shows a variation on the valvulotome 301 that has a greater ability 
to self-locate in the vein. The valvulotome 301 is similar to the 
valvulotome 1 previously described except for the addition of two convex 
spring pieces. Components corresponding to those in the embodiment shown 
in FIG. 1 are indicated by the same reference numbers with 300 added. The 
first convex spring piece 303 is attached to the shaft 306. The second 
convex spring piece 308 is attached to the distal end of the third section 
386 of the extension 351, extending out beyond the tip 357. The second 
convex spring piece 308 has a rounded nose 313 to prevent the spring piece 
from damaging the vein into which it is inserted. Both convex spring 
pieces are coplanar with the plane of the extension 351 and the blade 311 
but are on the opposite side of the shaft 306 from the blade 311. The 
convex spring pieces 303 and 308 are preferably made from springy 
stainless steel and are spot welded to the shaft 306 and the third section 
386. Alternatively springy plastic spring pieces 303 and 308 can be 
attached by means of a suitable adhesive. 
The convex spring pieces 303 and 308 increase the overall width of the 
valvulotome 301 so that it is somewhat greater than the diameter of the 
vein into which the valvulotome 301 is to be inserted. The convex spring 
pieces 303 and 308 keep the tip 357, the shaft 306, and the back 302 of 
the blade in contact with the wall of the vein. This increases the 
possibility of the proximal end 327 of the blade entering a valve pocket 
when the valvulotome is withdrawn through the vein. 
The convex spring pieces 303 and 308 can be attached to an operating lever 
(not shown) controlled from the proximal end of the valvulotome. The 
operating lever elongates the convex spring pieces, which lowers their 
profile. After the first leaflet of a valve is cut, the operating lever is 
operated to lower the profile of the convex spring pieces, which allows 
the valvulotome to be rotated more easily. After the valvulotome has been 
rotated, the operating lever is the operated once more to raise the convex 
spring pieces prior to cutting the second leaflet of the valve. 
Preferred embodiments of the valvulotome according to the invention are 
shown in FIGS. 12A-12B and 13A-13B. In the preferred embodiment, the 
safety of the valvulotome is further increased by protecting the sharpened 
parts of the blade more intimately. Production is simplified by mounting 
the blade in a one-piece casting. The preferred embodiment also used a 
laterally-extending guide wire to move the cutter head laterally in the 
vein. This ensures engagement of the free end of the cutting blade with 
the valve leaflet prior to cutting the leaflet. The laterally extending 
guide wire is retractable and adjustable, so that the valvulotome can be 
used in veins of different diameters, and can also adapt to the change in 
diameter that occurs along the length of a single vein. 
The valvulotome consists of three basic components: the cutting head 401, 
the operating handle 403, and the hollow shaft 405A or 405B. In the 
following description, a reference to the shaft 405 or the hollow shaft 
405 will refer to the hollow shaft 405A or the hollow shaft 405B. The 
valvulotome 400A shown in FIGS. 12A-12B has a flexible shaft 405A and is 
for use in in-situ by-pass procedures; the valvulotome 400B shown in FIGS. 
13A and 13B has the shorter, rigid shaft 405B, and is for disrupting the 
valves in vein segments to be used in CABG procedures. The operating 
handle 403 and the shaft 405A, 405B enable the surgeon to extend and 
retract the guide wire 407, as shown in FIG. 12B, when the cutting head 
401 is in the vein and as will be described in more detail below. 
Details of the cutting head 401 are shown in FIGS. 14A-14E. The vein cutter 
is mounted on the distal end of the shaft 405. The main components of the 
vein cutter are the haft 411 in which is mounted the cutting blade 413 The 
guide wire 407 extends from the shaft 405 into the slot 409 in the haft. 
The haft 411 includes the substantially cylindrical central portion 415, on 
each end of which are the opposed frusto-conical portions 417 and 419. The 
haft is preferably a single casting of a suitable metal, preferably 
stainless steel. Aluminium is a suitable alternative. Alternatively, the 
haft may be a molding of a suitable plastic, such as fibre-reinforced 
polycarbonate, or may be machined from suitable metal or plastic stock. 
The haft is preferably finished in a dark color, such as black. The 
orientation mark 455 is placed on the haft on the same side as the back of 
the blade. The orientation mark is of a contrasting color, for example, 
white, and enables the orientation of the cutting head to be seen through 
the translucent wall of the vein, or directly using angioscopy. 
The distal frusto-conical portion 419 of the haft 411 terminates in the 
rounded nose 421. The relatively large, rounded nose 421 enables the 
cutting head 401 to be advanced up the vein without the risk of snagging 
side branches of the vein. The blind bore 423, which receives the distal 
end 425 of the guide wire 407, is formed inside the distal frusto-conical 
portion 419, as shown in FIG. 14F. The blade slot 427, in which the 
cutting blade 413 is mounted, is formed in the side of the distal 
frusto-conical portion. Finally, the distal part of the slot 409, which 
accommodates the guide wire 407, is formed in the side of the distal 
frusto-conical portion 419, opposite the blade slot 427. 
The proximal frusto-conical portion 417 of the haft 411 is formed with the 
axial bore 429 which accommodates the shaft 405. Formed in the side of the 
distal portion of the proximal frusto-conical portion is the proximal part 
of the slot 409, which accommodates the guide wire 407 and communicates 
with the bore 429. 
The central part of the slot 409, which accommodates the guide wire 407, is 
formed in the side of the central cylindrical portion 415 of the haft 411. 
The blade recess 431 is formed in the side of the haft 411, opposite the 
slot 409. As will be described in more detail below, the blade recess 
protects the vein wall from the sharpened edge 433 of the cutting blade. 
The blade recess also includes the shoulder 435 at its proximal end. As 
will be described in more detail below, the shoulder protects the vein 
wall from the proximal end 437 of the cutting blade. 
The cutting blade 413 is flat and has a shape similar to that of the blade 
of a scythe, except that its free end 437 is rounded and is at least 
partially blunt. The cutting blade extends proximally from its fixed end 
438 mounted in the blade slot 427 in the distal frusto-conical portion 419 
of the haft, and terminates in the rounded free end 437. Most of the 
cutting blade lies within the blade recess 431. The cutting blade also 
includes the opposed flat sides 416 and 418, the sharpened edge 433 
between the flat sides, and the dull back 439 between the flat sides, 
opposite the sharpened edge. 
The sharpened edge 433 of the cutting blade faces into the blade recess 
431, and is coplanar with the long axis of the haft 411. The sharpened 
edge 433 extends proximally from the deepest part of the blade recess, 
arcing outwards to a maximum spacing from the blade recess, and arcing 
back slightly into the blade recess at its proximal end, adjacent the free 
end 437. The proximal end of the sharpened edge 433 is spaced from the 
blade recess 431 by the spacing d, which is chosen to be wide enough to 
admit a vein leaflet, typically about 1 mm. 
The back 439 of the cutting blade, remote from the sharpened edge 433, is 
blunt. The back of the cutting blade extends proximally from the junction 
441 between the distal end of the blade recess 431 and the surface of the 
distal frusto-conical portion 419 of the haft 411, arcing slightly 
outwards to a maximum spacing from the blade recess, and arcing back into 
the blade recess towards its proximal end, adjacent the free end 437, such 
that the proximal end lies within the blade recess. 
An end view of the free end 437 of the cutting blade 413 is shown in FIG. 
14E. The free end 437 is approximately semi-circular, and includes an 
inwards-facing part 445, which faces the long axis of the haft 411, is 
sharp, and forms a continuation of the sharpened edge 433. The free end 
also includes a proximal-facing part 443, which faces proximally, is 
blunt, and forms a continuation of the blunt back 439. The proximal-facing 
part 443 of the free end is blunt to prevent it from accidentally cutting 
the vein wall if it comes into contact with the vein wall. 
The shape of the cutting blade 413, and the mounting of the cutting blade 
in the blade recess 431 of the haft 411 are such that the cutting blade 
can be advanced or withdrawn in the vein with a negligible risk of the 
cutting blade accidentally cutting the vein, but can cut the vein leaflets 
completely when required to do so. When the cutting head 401 is advanced 
through the vein, the rounded nose 421 and gently curved sides of the haft 
411 and the blunt back 439 of the cutting blade are presented to the vein 
wall. None of these parts is capable of cutting the vein wall. The haft 
411 guards the vein wall from the sharpened edge 433 of the cutting blade 
413. The back 439 of the cutting blade, which is blunt, bounds the vein 
cutter in the radial direction remote from the haft 411. Towards the free 
end 437, the cutting blade 413 curves inwards into the blade recess 431, 
where it is protected by the shoulder 435. The shoulder protects the vein 
wall from the free end 437 of the cutting blade 413, which is sharp over 
its inwards-facing part 445, when the cutting head 401 is withdrawn from 
the vein. Also, when the vein cutter is withdrawn, the shoulder 435 and 
the curve of the proximal portion of the cutting blade 413 into the blade 
recess 431 prevent the free end 437 of the cutting blade from accidentally 
entering side branches of the vein. This, in turn, prevents exposure of 
the vein wall to the sharpened edge 433 of the cutting blade. Finally, the 
spacing d between the proximal end of the sharpened edge 433 of the 
cutting blade and the blade recess 431 is chosen to be small enough to 
prevent parts of the vein other than the leaflet from entering the blade 
recess. This, in turn, prevents such parts of the vein from being exposed 
to the sharpened edge 433 of the cutting blade. 
The sharpened edge 433 and the inwards-facing part 445 of the free end of 
the cutting blade are sharp, but the arrangement of the cutting blade 413 
relative to the haft 411 ensures that the only portions of the vein that 
are exposed to these sharp edges are the vein leaflets that enter the 
blade recess 431. The way in which the valvulotome 400A or 400B cuts the 
vein leaflets will be described in detail below. 
The cutting head 401 is mounted on the distal end of the hollow shaft 405, 
the proximal end of which is attached to the operating handle 403. In the 
embodiment shown in FIGS. 12A and 12B, the flexible hollow shaft 405A has 
a stainless-steel braid inner covered by a polyurethane sleeve. The braid 
inner improves the torque characteristics of the shaft 405A, but may be 
omitted if desired. The hollow shaft 405A is about 650 mm long with an 
outside diameter of about 1 mm and an internal diameter of about 0.6 mm. 
Distance marks 449 are provided at predetermined intervals of about 100 mm 
on the outer surface of the hollow shaft 405A to enable the surgeon the 
determine the location of the cutting head 401 relative to the insertion 
point of the shaft into the vein. 
In the embodiment shown in FIGS. 13A and 13B, the hollow shaft 405B is a 
rigid stainless-steel tube about 30 cm long with an external diameter of 
about 1.0 mm and an internal diameter of about 0.6 mm. Distance marks 449 
are provided at predetermined intervals on the outer surface of the hollow 
shaft 405B to enable the surgeon the determine the location of the cutting 
head 401 relative to the insertion point of the shaft into the vein. 
The guide wire 407 runs from the operating handle 403 to the vein cutter 
401 through the bore of the shaft 405. The guide wire is preferably a 
wire-wrapped single filament of stainless steel with an outside diameter 
of about 0.55 mm. The proximal end (not shown) of the guide wire is 
attached to the operating sleeve 447 of the operating handle 403. The 
surgeon slides the operating sleeve distally relative to the operating 
handle to extend the guide wire 407 radially from the vein cutter 401, and 
slides the operating sleeve proximally to retract the guide wire. Sliding 
the operating sleeve distally moves the guide wire distally relative to 
the shaft 405. The distal end 425 of the guide wire is fixed relative to 
distal end of the vein cutter 401, so the distal movement of the guide 
wire causes the guide wire to bow outwards from the slot 409 in the haft 
411, as shown in FIGS. 14D and 14F. Indents (not shown) are provided 
between the operating sleeve 447 and the operating handle 403, so that the 
operating sleeve will stay in any one of the sliding positions that 
produces one of the intermediate extensions, such as the intermediate 
extension 451, or the full extension 453, of the guide wire shown in FIG. 
14D. The selective adjustability of the guide wire extension enables the 
valvulotome according to the invention to be used in veins of differing 
diameters, and also enables the valvulotome to adapt to the change in 
diameter that occurs along the length of a single vein. 
The cutting head 401 is advanced through the vein with the guide wire 407 
retracted, as shown in FIGS. 12A and 13A. When the cutting head is 
withdrawn in the vein to cut the valve leaflet, the operating sleeve 447 
on the operating handle 403 is operated to extend the guide wire 407 from 
the slot 409 in the back of the haft 411, as shown in FIGS. 12B and 13B. 
The guide wire contacts the vein wall, and forces the dull back 439 of the 
cutting blade 413 into contact with the opposite side of the vein wall. 
This ensures that, as the cutting head is further withdrawn, the valve 
leaflet to be cut will enter the blade recess 431, where it can be cut by 
the sharpened edge 433. 
A method according to the invention of using the embodiment of the 
valvulotome 1 according to the invention shown in FIG. 1 to disrupt vein 
valves in the course of a coronary artery bypass procedure is illustrated 
in FIGS. 1 and 15A through 15H. The method can also be adapted for use in 
an in-situ bypass procedure. 
A suitably-sized section of the saphenous vein V is removed from the leg 
and placed on a side table. The side branches, such as B1 and B2 are 
preferably tied off before the valvulotome 1 is used. This enables the 
vein to be inflated to determine the location of the valves. The syringe 
26 is filled with physiologic solution 31, or some other suitable fluid, 
and the syringe 26 is screwed onto the luer hub 21. The resulting 
valvulotome assembly is shown in FIG. 1. 
The surgeon places the vein V on the table, and holds it down with one 
hand. With the other hand, the surgeon carefully inserts the valvulotome 1 
into the smaller-diameter end of the vein and advances the valvulotome 1 
up the vein. Alternatively, the surgeon can hold the smaller-diameter end 
of the vein V with tweezers held in one hand. 
By starting at the smaller-diameter end of the vein, the valvulotome is 
advanced in the normal direction indicated by the arrow 5. The valvulotome 
1 therefore passes easily though the valves in the vein, such as the valve 
Val shown in FIG. 15A. The surgeon can monitor the progress of the 
valvulotome from outside the vein by observing the length of the shaft 6 
projecting from the proximal end of the vein V. The position of the 
valvulotome can also be determined by observing the position of colored 
markings on the valvulotome 1 through the translucent wall of the vein or 
the imprint of the valvulotome on the vein wall if the vein wall is 
opaque. 
Possible snagging of the valvulotome 1 on a flap on the intimal surface of 
the vein V as the valvulotome is advanced through the vein can be avoided 
by using an alternative method of advancing the valvulotome. The 
alternative method uses the version of the valvulotome 1 that includes the 
traction point 181 (FIG. 3A). According to the method, the surgeon holds 
the vein V using one hand, as described above, and threads a guide wire up 
the vein from the smaller-diameter end with the other hand. When the 
distal end of the guide wire reaches the larger-diameter end of the vein, 
the surgeon attaches one end of a piece of suture to the proximal end of 
the guide wire and, pulling on the distal end of the guide wire, pulls the 
suture through to the larger-diameter end of the vein V. The surgeon then 
attaches the other end of the suture to the traction point 181 of the 
valvulotome assembly. The surgeon then places the valvulotome assembly and 
the vein V in a linear arrangement on the table and introduces the distal 
end of the valvulotome 1 into the smaller-diameter end of the vein. The 
surgeon holds the smaller-diameter end of the vein V with tweezers held in 
one hand and gently pulls on the suture to advance the valvulotome 
assembly through the vein V towards its larger-diameter end. 
With either method of advancing the valvulotome through the vein V, when 
the valvulotome reaches the larger-diameter end of the vein, the surgeon 
withdraws it slightly. The surgeon then grips the larger-diameter end of 
the vein V with forceps F held in the hand that formerly was holding the 
smaller-diameter end of the vein V, as shown in FIG. 1. The forceps F grip 
the vein so as to seal the larger-diameter end of the vein. The forceps F 
also can clamp the vein to a towel covering the table on which the vein is 
placed. This secures the larger-diameter end of the vein to the table and 
enables the surgeon to remove his/her hand from the forceps F when needed. 
The surgeon then depresses the plunger 27 of the syringe 26. This forces 
physiologic solution out of the syringe 26, through the shaft 6, and out 
of the hole 192, to form the jet of solution indicated by the arrow 196, 
as shown in FIG. 15B. The solution entering the part of the vein between 
the forceps F and the most distal valve Va1 in the vein V creates a 
pressure differential across the valve Va1 and causes the valve Va1 to 
close around the shaft 6 of the valvulotome 1. Once the valve Va1 is 
closed, pressure builds up in the part of the vein between the forceps F 
and the valve Va1, causing the vein to inflate, as shown in FIG. 15C. The 
part of the vein below the valve Va1 is not pressurized, and therefore 
does not inflate. This enables the surgeon to determine the location of 
the valve Va1 along the length of the vein V. Providing irrigation through 
the valvulotome enables the valve cutting process to be carried out by a 
single surgeon without assistance. With conventional techniques, 
irrigation is introduced into the top of the vein which requires a third 
hand, i.e., that of an assistant. 
The surgeon observes the position of the extension 51 of the valvulotome 1 
in the vein and withdraws the valvulotome 1 until the extension 51 is in 
the vicinity of the valve Va1. Holding the syringe 26 lightly, the surgeon 
carefully withdraws the valvulotome 1 until resistance is felt. This 
indicates that the proximal end 127 of the blade of the valvulotome has 
contacted one of the leaflets, say the leaflet L1, of the valve Va1. 
Further gentle withdrawing pressure brings the proximal end 127 of the 
blade into the valve pocket P1, as shown in FIG. 15D. The surgeon holds 
the valvulotome gently to allow the valvulotome assembly to rotate as the 
blade slides up the leaflet L1 to enable the proximal end 127 of the blade 
to enter into the valve pocket P1 as deeply as possible, and to be 
centered within the valve pocket. 
With the proximal end 127 of the blade located in the valve pocket, the 
surgeon applies greater withdrawing pressure to cause the proximal end of 
the blade to pierce the leaflet L1 at its apex, as shown in FIG. 15E. Once 
the proximal end of the blade has pierced through the leaflet, the leaflet 
is exposed to the sharp cutting edge 112 of the blade, which enables the 
withdrawing pressure to be reduced. The valvulotome assembly is then 
steadily withdrawn causing the cutting edge 112 of the blade to cut down 
the center of the leaflet towards the edge E, as shown in FIG. 15F. While 
cutting, the blade applies a tensile force in the direction away from the 
apex of the leaflet to the point being cut. The leaflet, being relatively 
strong in tension, provides the resistance necessary for cutting to take 
place. Finally, the blade 11 breaks through the edge E1 of the leaflet L1 
substantially in the center of the leaflet, as shown in FIG. 15G, and the 
resistance to withdrawing the valvulotome assembly drops significantly. 
The action of the valvulotome according to the invention is to be 
contrasted with the prior art Mills valvulotome shown in FIG. 11. The 
Mills valvulotome cuts the leaflet from the edge E towards the valve 
pocket P1, which places the leaflet in compression, in which direction the 
leaflet is weak. It is therefore much more difficult to obtain a clean cut 
up the center of the leaflet from edge of the leaflet to the valve pocket 
with the Mills valvulotome than to make a clean cut up the center of the 
leaflet from the valve pocket to the edge with the valvulotome according 
to the invention. 
The surgeon then advances the valvulotome assembly 1 back up the vein V 
past the valve Va1. The surgeon can observe the position of the head of 
the valvulotome through the translucent wall of the vein. Once the blade 
of the valvulotome has passed the valve Va1, the surgeon rotates the 
syringe, and hence the valvulotome, through 180 degrees to align the blade 
with the second leaflet L2, as shown in FIG. 15H. If the cut first leaflet 
L1 has not allowed much of the solution to pass, and hence the vein above 
the valve Va1 is still pressurized, the surgeon can proceed with cutting 
the second leaflet L2 by withdrawing the valvulotome as described above. 
In the more likely event that the cut first leaflet L1 has allowed 
substantially all the solution to pass and the vein above the valve Va1 is 
unpressurized, the surgeon once more depresses the plunger 27 of the 
syringe 26 (FIG. 1) to cause solution to be emitted from the hole 192 in 
the third section 86. A jet of solution indicated by the arrow 196 in FIG. 
15H is emitted in the direction of the blade 11 which is aligned with the 
second leaflet L2. The force of the solution impinging on the leaflet L2 
deflects the leaflet L2 away from the wall of the vein and bring it into 
contact with the shaft 6 of the valvulotome 1. 
When the surgeon withdraws the valvulotome assembly, the edge E2 of the 
leaflet L2 enters the gap between the second portion 81 of the shaft and 
the proximal end 127 of the blade. Further withdrawal of the valvulotome 
assembly brings the proximal end 127 of the blade into the valve pocket 
P2, guided by the inner surface of the leaflet L2. Once the proximal end 
127 of the blade has penetrated the valve pocket P2, the leaflet L2 is cut 
up its center as described above. 
After both leaflets L1 and L2 of the valve Va1 have been cut, the surgeon 
depresses the plunger 27 of the syringe 26 once more to emit more solution 
into the vein. This pressurizes the part of the vein from the forceps F 
down to the next valve in the vein, Va2 (FIG. 1), and enables the surgeon 
to determine the position of the valve Va2. The surgeon cuts both leaflets 
of the valve Va2 using the procedure described above, and repeats the 
valve locating and cutting procedure described above until all the valves 
in the vein have been cut. The vein is then ready for use in a coronary 
artery bypass procedure. 
The method according to the invention of using the preferred embodiment of 
the valvulotome according to the invention will be described next with 
reference to FIGS. 16A-16G. In the following description, use of the 
valvulotome 400A shown in FIG. 12A in the course of an in-situ procedure 
will be described. The method of using the valvulotome 400B to disrupt the 
valves in a vein segment to be used in a CABG procedure is similar, and 
will therefore not be described separately. 
The cutting head 401 with the guide wire 407 in its retracted state is 
inserted into the smaller-diameter end of the vein V. The shaft 405 is 
manipulated to advance the vein cutter up the vein in the direction shown 
by the arrow 501, shown in FIG. 16A. The cutting head is advanced in the 
direction of normal blood flow, and the rounded nose 421 of the cutting 
head therefore passes easily though the valves in the vein, such as the 
valve Va1. 
The position of the cutting head in the vein can be determined by observing 
the position of the distance marks 449 (FIG. 12A) on the shaft 405 
relative to the point of insertion of the shaft into the vein. The 
position of the cutting head and its angular orientation in the vein can 
be determined by distally sliding the operating sleeve 447 in the 
operating handle 403 (FIG. 12A) to extend the guide wire 407. This presses 
the guide wire and the haft 411 against opposite portions of the vein 
wall, which can be seen from outside the vein. It can also be seen whether 
it is the guide wire or the haft that is in contact with the vein wall 
closest to the surgeon. This enables the angular orientation of the 
cutting head 401 to be determined and corrected, if necessary. 
After the cutting head 401 has passed through the valve Va1, the operating 
sleeve 447 in the operating handle 403 (FIG. 12A) is slid distally to 
extend the guide wire 407, as indicated by the arrow 503. The guide wire 
contacts the vein wall and moves the cutting head 401 laterally, as 
indicated by the arrow 505. This brings the dull back 439 of the cutting 
blade 413 into contact with the vein wall, and brings the haft 411 into 
contact with the leaflet L1, as shown in FIG. 16B. 
The shaft 405 is then manipulated to withdraw the cutting head 401 in the 
direction indicated by the arrow 507 in FIG. 16C. As the cutting head is 
withdrawn, the edge E of the leaflet L1 remains in contact with the 
proximal frusto-conical portion 417 of the haft 411. After the shoulder 
435 of the blade recess 431 passes the edge E of the leaflet, the edge E 
slides into the blade recess. Further withdrawal of the shaft 405 brings 
the edge E of the leaflet into the gap between the haft 411 and the 
sharpened edge 433 of the cutting blade 413, as shown in FIG. 16D. This 
exposes part of the leaflet to the sharpened edge 433 of the cutting blade 
and to the sharp inwards-facing part 445 of the free end 437 of the 
cutting blade. 
As the cutting head 401 is further withdrawn, the dull proximalfacing part 
443 of the free end 437 of the cutting blade 413 slides up the back of the 
leaflet L1, and lodges in the valve pocket P1 between the leaflet L1 and 
the vein V, as shown in FIG. 16D. During this pan of the procedure, the 
surgeon holds the shaft 405 lightly to allow the cutting head to rotate as 
the free end of the cutting blade slides up the leaflet L1. This enables 
the free end 437 of the cutting blade to enter into the valve pocket P1 as 
deeply as possible, and centers the cutting blade on the leaflet. 
With the dull proximal-facing part 443 of the free end 437 of the cutting 
blade 413 located deep in the valve pocket, the shaft 405 is further 
manipulated to withdraw the cutting head 401 further. This causes the dull 
proximal-facing pan 443 of the free end 437 of the cutting blade 413 to 
pierce the leaflet L1 at its apex in the valve pocket P1, as shown in FIG. 
16E. Once the dull proximal-facing part of the free end of the cutting 
blade has pierced through the leaflet, the leaflet is exposed to the 
sharpened edge 433 of the cutting blade. The cutting head is then further 
withdrawn, causing the sharpened edge 433 of the cutting blade to cut down 
the center of the leaflet from the apex towards the edge E, as shown in 
FIG. 16F. 
While cutting, the cutting blade 413 applies a tensile force to the leaflet 
L1 in the direction away from the apex of the leaflet towards the point of 
contact between the cutting blade and the leaflet. The leaflet is 
relatively strong in tension, and so can provide the resistance necessary 
for cutting to take place. Finally, the cutting blade 433 breaks through 
the edge E of the leaflet L1, substantially in the center of the leaflet. 
After the first leaflet is cut, the operating sleeve 447 on the operating 
handle 403 (FIG. 12A) is slid proximally to retract the guide wire 407, 
the shaft 405 is manipulated to rotate the cutting head 401 through 180 
degrees about its long axis, as shown by the arrow 509 in FIG. 16G. The 
shaft 5 is then manipulated to advance the cutting head up the vein V past 
the valve Va1 a second time to cut the leaflet L2 by means of the steps 
illustrated in FIGS. 16B-16G. 
Although illustrative embodiments of the invention have been described 
herein in detail, it is to be understood that the invention is not limited 
to the precise embodiments described, and that various modifications may 
be practiced within the scope of the invention defined by the appended 
claims.