Methods and systems for vein harvesting

Information

  • Patent Grant
  • 6551314
  • Patent Number
    6,551,314
  • Date Filed
    Wednesday, April 3, 2002
    22 years ago
  • Date Issued
    Tuesday, April 22, 2003
    21 years ago
Abstract
Veins are removed using a pull catheter introduced over a guidewire which extends between first and second percutaneous access points. Optionally, a side branch management tool including an excision device and/or a viewing scope can be advanced over the same guidewire in the direction opposite to that of the pull catheter. In that way, as the pull catheter inverts the vein being removed, side branches can be selectively viewed and/or severed using the side branch management tool.
Description




BACKGROUND OF THE INVENTION




1. Field of the Invention




The present invention relates generally to medical apparatus and methods. More particularly, the present invention relates to methods and systems for intraluminal vein harvesting or removal.




Cardiac and peripheral vascular bypass surgery commonly employs veins harvested from the patient undergoing surgery, usually obtained by autologous vein harvesting procedures. Vein harvesting commonly relies on making a long skin incision to expose the length of vein which is to be excised and removed. Such exposure of the vein allows for dissection and division of the veins which branch from the portion of vein being removed. The greater saphenous vein in the leg is most commonly used, followed by the lesser saphenous vein in the leg and the basilic and cephalic veins in the arm.




Such long incisions made for vein harvesting are highly traumatic and problematic for a number of reasons. First, patients requiring bypass surgery often suffer from other diseases, such as diabetes, obesity, malnutrition, which may impede healing and increase the risk of infection of the skin incisions. Additionally, the cosmetic scarring which results from the long incisions is of concern to many patients.




To partly overcome these drawbacks, systems for the endoscopic harvesting of veins have been developed. Such systems, presently available from suppliers such as Ethicon and General Surgical Innovations, rely on introduction of endoscopic apparatus through an incision at one end of the vein segment to be removed. The apparatus includes a viewing scope, a mechanism for dissecting the vein from the surrounding tissue bed, and additional mechanisms for dissecting the vein from side branches to facilitate removal. Other systems, such as that available from Guidant Corporation, use gas insufflation to create a working space around the vein and rely on percutaneously introduced instruments for excising the vein. In all cases, the systems are expensive, cumbersome to use, and still traumatic to the patient.




For these reasons, it would be desirable to provide improved vein harvesting apparatus and methods for their use, which are minimally traumatic to the patient, which do not require long skin penetrations or incisions at points between the two ends of the vein segment being removed, which permit selective excision of the venous side branches and optional sealing of the side branches, and which provide a vein segment which is maintained relatively intact allows for valve removal and which can be used for bypass grafting or other purposes with minimal additional preparation. It would be further desirable if the systems and methods were also useful for vein stripping and removal for treatment of varicose veins and other conditions. The system and methods should optionally permit endoscopic visualization of the vein while it is being removed and remove relatively long vein segments with a single device deployment. At least some of these objectives will be met by the inventions described hereinafter.




2. Description of the Background Art




Intraluminal vein removal and modification devices are described in U.S. Pat. Nos. 6,165,172; 6,030,396; 6,013,073; 5,843,104; 4,528,982; 3,788,325; 3,568,677; 3,185,155; 3,045,676; 2,770,334; and PCT Publication WO 00/45691. Endoscopic and extraluminal vein removal devices are described in U.S. Pat. Nos. 6,022,313; 5,817,013; 4,793,346; and Re. 36,053. Patents relating to vein harvesting assigned to General Surgical Innovations include U.S. Pat. Nos. 6,196,968; 6,077,289; 6,068,639; 5,993,412; 5,968,066; 5,944,734; 5,899,913; and 5,853,417. Patents relating to vein harvesting assigned to Ethicon include U.S. Pat. Nos. 6,193,653; 5,928,138; 5,922,004; 5,902,315; and 5,667,480.




BRIEF SUMMARY OF THE INVENTION




The present invention provides improved methods, systems, and kits for removing veins from their surrounding tissue beds. While the methods will find their greatest use in the harvesting of veins for subsequent implantation in bypass and other procedures, they will also find use for removing varicose veins and diseased veins for cosmetic and other purposes. When used for vein harvesting, the target veins will most often be the greater saphenous vein or the lesser saphenous vein in the leg, and the basilic and cephalic veins in the arm.




The present invention is advantageous in a number of respects. It does not require a long incision along the length of the vein segment to be removed. Instead, it is less invasive and may be performed via surgical cut downs at each end of the vein segment to be removed. Additionally, the present invention allows for selective severing of venous side branches from the vein segment being removed during the removal process. In one embodiment of the present invention, such selective severing (and optionally subsequent sealing) of the side branches may be performed under direct endoscopic visualization. In another embodiment, such selective severing is achieved in a blind fashion, greatly simplifying the protocols. Use of the methods and apparatus of the present invention has been found to produce very long and high quality vein segments suitable for coronary artery and other bypass and implantation procedures. In some embodiments, the apparatus of the present invention facilitates manipulation of the long vein segments after they have been removed, in particular allowing trimming of the valves and other preparation steps to be performed while the vein remains over a long distal portion of the vein removal catheter.




In a first aspect, methods according to the present invention for vein removal comprise exposing first and second spaced-apart locations along a vein, typically by surgically exposing the locations, commonly referred to as a surgical cut down. The veins are then transected at each of the locations so that a segment of the vein is isolated and ready for removal from the surrounding tissue bed. The remaining portions of the vein, i.e., those which are not to be removed, may have their free ends tied off or otherwise sealed.




After exposing and transecting the ends of the venous segment to be removed, a guidewire is passed through a lumen between the first and second locations. The length of the guidewire is sufficient to permit introduction of intraluminal devices over at least one end, and preferably over both ends, of the guidewire to perform the methods described herein. In particular, a pull catheter will be introduced over the guidewire from the first location until a distal end of the pull catheter reaches the second location. Usually, the first location will be that which is closest to the patient's heart and which therefore has a larger diameter.




Alternatively, the pull catheter may have a fixed rail at its distal end or the pull catheter may be provided with a rail immobilization mechanism for selectively holding a movable rail with the distal end of the movable rail exposed distally out the pull catheter. In either case, the pull catheter may be introduced to and through the target vein without the prior positioning of a movable rail. With a fixed rail, the rail would be designed to be long enough to allow introduction of a side branch management catheter (as described below) excision or other catheter over a movable rail in a direction opposite to that of the pull catheter. An advantage of using a pull catheter and a fixed rail is that there is no need to separately manipulate a long guidewire, which when both a pull catheter and an side branch management tool are to be introduced, may have a length which is more than three times that of the individual catheters. A similar advantage is found with the use of the immobilized rail, where the rail could have a length only slightly longer than that of the pull catheter. The immobilized guidewire, however, could be released after the pull catheter is extended distally so that it could remain in place as the pull catheter is withdrawn from the vessel. An advantage of both these alternative rail designs, is that introduction of a side branch management or other catheter from the remote tissue penetration, as described below, will be more easier. In addition, the fixed rail embodiment provides support for the inverted vein after removal and can help in re-inverting the vein and other vein preparation steps.




After the pull catheter has been introduced to the desired location, the free end of the vein which has been transected near the second location is attached to the distal catheter end, typically by suturing, clipping, tying, or otherwise circumferentially securing the venous end to the distal end of the pull catheter. The pull catheter is then pulled in a direction back from the second location toward the first location so that the end of the “free” venous segment to be removed is inverted. In particular, the free end is pulled inwardly and to the lumen of the venous segment with a continually retracting inversion fold line being exposed as the vein is pulled from the surrounding tissue bed.




As the venous segment is inverted and pulled from the surrounding tissue bed, the venous wall will be pulled from the side branches which extend radially outwardly into the surrounding tissue bed. In some instances, the wall of the venous segment can simply be pulled or evulsed from the attached end of the side branch. For larger side branches, however, it may be desirable to divide and optionally occlude the side branches from the wall of the venous segment prior to removal of the vein. According to the present invention, this can be accomplished by introducing a side branch management tool, preferably over the guidewire, through the second location and advancing a distal end of the side branch management tool so that it follows an inversion line of the venous segment as it is being inverted. The side branch management tool will usually include at least a cutting tool and may optionally include a sealing tool and/or viewing optics. The cutting tool can be a deployable or fixed blade, an electrosurgical cutting tool, a shearing blade, or the like. The occlusion device could be an electrocautery device, a clip applier, a hemostatic or glue applicator, or the like. The optional optical viewing system will normally comprise an optical fiber system, but could comprise a CCD or other electronic monitor directly on the tool.




Severing of the side branches can be achieved in a number of ways, including both blind and under visualization. Removal of the side branches under visualization can be accomplished, for example, using a catheter having a viewing scope positioned in or alongside the side branch management tool to visualize the inversion folding edge, referred to herein as the inversion line, as the venous segment is inverted. When side branches which need to be severed are observed, a separate or integral cutting blade or other tool can be advanced from the side branch management tool and used to selectively cut the side branch near its attachment point to the venous segment. Blind side branch management tools may comprise simple tubular cutting blades or tubular cutting blades having castellated or serpentine cutting edges. Alternatively, blind tools may comprise a blunt or acorn tip which may be advanced so that it embeds into the inverted venous wall as it is being pulled. Fixed or actuable blade(s) on the tool may then be used to cut the side branches when the user determines that a side branch is impeding the vein removal. Usually, the catheter tip will be rotated so that the blade circumscribes a line positioned just behind the inversion line, thus selectively isolating, tensioning and severing the side branches which are attached at that point. A variety of other cutting mechanisms and protocols could also be used, such as a gripping or clamping tool that pulls vessel out by it's root.




A particular advantage of the present invention is that the visualization and optional cutting of the side branches is accomplished using a side branch management tool introduced in a direction opposite to that of the pull catheter. In contrast to the endoscopic devices of the prior art which combine vessel dissection and side branch excision functions, the separate pull catheter and side branch management tool of the present invention can have relatively low profiles greatly reducing the trauma to the patient which results from advancing the catheters subcutaneously through the tissue bed. Moreover, as the vein is inverted, the side branch management tool can utilize the space left by the removed vein in the tissue bed so that additional dissection is minimized.




Optionally, after the side branches are cut, the side branch management tool can be used to seal portions of the side branch which remains in the tissue bed. For example, the cutting blade which is used to sever the side branches may be connected to an electrocautery power supply (RF or DC current) in order to cauterize the side branches. Alternatively, the side branches could be clipped or stapled, or as a third alternative, the side branches could be sealed using a tissue sealant, such as polyacrylate or a thrombin-based hemostatic agent.




In a second aspect of the present invention, systems for the removal of veins, either for harvesting or varicose vein removal, comprise a pull catheter, a side branch management tool, and usually a separate (immovable) guidewire. The guidewire will be capable of extending from a proximal location to a spaced-apart distal location along a vein. The guidewire will typically have a length in the range from 180 cm to 260 cm and a diameter in the range from 0.2 mm to 0.9 mm (usually 0.035″).




The pull catheter will comprise a catheter body having at least one lumen therethrough adapted to permit introduction over the guidewire. Typically, the pull catheter will have an over-the-wire design where the guidewire lumen extends the entire length of the catheter body. Alternatively, the pull catheter could have a shortened guidewire lumen extending over only a portion of the distal end, typically from 5 cm to 25 cm, usually from 5 cm to 15 cm. As a still further alternative, the pull catheter could have a fixed rail at its distal end, typically having a length in the range from 80 cm to 100 cm, usually from 80 cm to 100 cm. When used with movable guidewires, the pull catheter can optionally have a mechanism for capturing the guidewire, such as a clamp, so that a distal portion of the movable guidewire can be extended distally of the distal end of the pull catheter and then immobilized in place. In this way, the pull catheter can be initially introduced through the lumen of the target lumen in a manner analogous to the use of a catheter having a fixed guidewire. After advancing the pull catheter to the remote end of the target lumen, the guidewire can be grasped by the user and released from the catheter so that the catheter may be freely advanced and retracted over the now-movable guidewire. The pull catheter can have at least a second lumen to permit the infusion of saline or other solutions, although combined guidewire and infusion lumens may also find use. As a still further option, the pull catheter may be provided with a balloon near its distal end, where the balloon can be inflated to help initiate inversion of the vein.




Provision will be made at or near the distal end of the pull catheter to permit attachment of a dissected end of the venous segment to be removed. Most simply, the surgeon could use a clip or directly suture the vein through a distal region of the pull catheter. No particular modification of the pull catheter is required. More usually, however, the pull catheter will have a transverse aperture therethrough to permit suture or other type of clipping device to be passed through the catheter and secured over the venous segment. Alternatively, a circumferential channel or trough may be formed in the catheter body to again facilitate suturing or other attachment of the venous wall to the catheter. Of course, the vein could be attached to the pull catheter using clips, staples, metal ties, C-clamps, or in a variety of other ways. In all cases, however, it will be preferable that the free end of the venous segment be attached substantially uniformly about its circumference so that force is transmitted evenly to the vein as it is pulled and inverted from the tissue bed.




The side branch management tool will also comprise a rigid body or catheter having a guidewire lumen or other means for being introduced over a guidewire. Again, the side branch management tool may have an over-the-wire design where a guidewire lumen extends the entire length of the catheter body. Alternatively, the length of the guidewire lumen can be shortened, generally to the ranges set forth above with regard to the pull catheter. The side branch management tool will typically also have some provision for dissecting or cutting the venous side branches from the venous segment which is being withdrawn.




Usually, the side branch management tool will include a fixed or retractable blade attached near a distal end of the side branch management tool. By rotating the catheter, or at least a portion thereof that has the blade, the blade will travel circumferentially around a path which can be aligned with the expected position of the side branches. Alternatively, the blade can have a generally tubular configuration so that it can cut along the entire circumferential surface of the tissue bed as it is being exposed by the venous segment being inverted. In all cases the blade can optionally be connected to an electrosurgical power supply so that the cutting may be enhanced by the application of DC or radiofrequency energy. In such cases, the power supply could also provide radiofrequency energy intended to cauterize the cut surfaces.




The side branch management tool may optionally be provided with a viewing scope to permit visualization of the side branches and to permit more careful positioning of the blade or associated cutting mechanism in order to sever the side branches. Usually, the side branch management tool will have a lumen or other channel for introducing a working tool for cutting the side branch under endoscopic visualization. Numerous blades, scissors, electrosurgical tools, and the like, could be introduced through the side branch management tool and used under endoscopic visualization to selectively cut the side branches. Alternatively, the cutting mechanism may be formed as an integral component of the catheter.




In a specific embodiment, the side branch management tool may have a distal tip that includes a feature, such as a notch or raised edge, to catch and tension a side branch prior to dissection. Such a feature allows the surgeon to feel when the tool has encountered a side branch and further allows the surgeon to then dissect the side branch by firmly engaging the feature against the side branch and rotating, translating, or otherwise manipulating the tool to dissect the side branch. If the side branch is sufficiently small (less than 2 mm in diameter) the surgeon may evulse the branch using forward traction on the side branch management tool. Usually, the tool will also be provided with a cutting blade or other cutting feature which allows the user to first capture and tension the side branch, optionally clip and then selectively actuate the cutting blade to dissect the side branch. Optionally, the side branch management tool will include visualization which permits the surgeon to view the side branch after it has been captured and to observe the side branch as it is being dissected by the cutting blade.




The sizes of both the pull catheter and the side branch management tool may vary depending on the particular venous segment which is to be withdrawn. For the greater and lesser saphenous veins and the basilic and cephalic veins, the catheter bodies will typically have a length in the range from 40 cm to 80 cm and a body diameter in the range from 4 mm to 12 mm.




Kits according to the present invention for vein removal will also comprise a guidewire, a pull catheter, and an side branch management tool. In addition to these components, which preferably will be as described above with respect to the systems, the kits will also include instructions for use, sending forth a method according to the present invention for vein removal. The methods may be any of the methods described herein above. Typically, the kits will further include packaging for holding the guidewire, pull catheter, and side branch management tool, preferably all in a sterile condition. Suitable packages include pouches, tubes, boxes, trays, and the like. The instructions for use will typically be printed on a sheet of paper, usually in the form of a product insert. Alternatively, the instructions for use may be printed directly on the packaging. In other cases, the instructions for use may be made available electronically, e.g., on CD-ROMs, sold as a part of the kit, or made available over the Internet. In all cases, the instructions for use will inform the user on how to use the physical components of the kit to perform the methods in an acceptable manner.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a perspective view of a first embodiment of a pull catheter constructed in accordance with the principles of the present invention.





FIG. 2

is an axial sectional view of a distal end of the catheter of FIG.


1


.





FIGS. 2A and 2B

are cross-sectional views taken along lines


2


A—


2


A and


2


B—


2


B of

FIG. 2

, respectively.





FIG. 3

is a perspective view of the distal end of a second embodiment of the pull catheter of the present invention.





FIG. 3A

is a side view of the distal end of the catheter of

FIG. 3

shown at a first orthogonal orientation.





FIG. 3B

is a side view of the distal end catheter of

FIG. 3

, shown at an orthogonal orientation which is 90° offset from that of FIG.


3


A.





FIG. 4

illustrates the incision locations on a patient's leg which are useful for removing the greater saphenous vein in the methods of the present invention.





FIG. 5

illustrates the introduction of a pull catheter through the lumen of a venous segment to be removed according to the methods of the present invention.





FIGS. 5A and 5B

illustrates the initial steps of first securing an excised end of the venous segment to be removed to the pull catheter and of initially inverting the venous segment, respectively





FIG. 5C

illustrates the introduction of a catheter with a viewing scope to observe the vein being inverted.





FIG. 5D

illustrates the selective severing of a side branch under observation using the viewing scope.





FIG. 6

is a perspective view of a blind side branch management tool having an actuable blade constructed in accordance with the principles of the present invention.





FIGS. 7A and 7B

illustrates use of the catheter of

FIG. 7

for tracking and serving a side branch attached to a venous segment being removed.





FIG. 8

illustrates another embodiment of an side branch management tool constructed in accordance with the principles of the present invention. The catheter of

FIG. 8

includes a tubular excision blade.





FIGS. 9A and 9B

illustrate the use of the side branch management tool of

FIG. 8

for cutting side branches from the venous segment being removed.





FIGS. 10-12

illustrate alternative distal end constructions for the pull catheters of the present invention.





FIG. 13

illustrates a specific embodiment of the side branch management tool of the present invention having a notched acorn structure at its distal end.





FIG. 14

is a detailed view of the notched acorn structure of FIG.


13


.





FIG. 15

is a detailed view, with portions broken away, of the handle of the side branch management tool of FIG.


13


.





FIGS. 16A-16C

illustrate actuation of a blade and the notched acorn structure of the catheter of FIG.


13


.





FIG. 17

illustrates a kit constructed in accordance with the principles of the present invention.











DESCRIPTION OF SPECIFIC EMBODIMENTS




Referring to

FIG. 1

, a first embodiment of a pull catheter


10


constructed in accordance with the principles of the present invention comprises a catheter body


12


having a distal end


14


and a proximal hub


16


. The catheter body


12


will preferably have the dimensions set forth above and may be composed of a single extrusion from a variety of conventional catheter materials such as natural or synthetic polymers, typically polyethylenes, polyvinylchlorides, polyurethanes, polyesters, polytetrafluorethylenes (PTFE's), nylon, silicone rubbers, and the like. Optionally, the catheter body will be reinforced with axial wires, braided layers, helical coils, or the like. The purpose of such enforcement will be to enhance the tensile strength of the catheter which is used primarily for pulling on the venous segment which is being removed.




Referring now to

FIGS. 2

,


2


A,


2


B, an exemplary catheter body


12


has a guidewire lumen


20


which extends the entire length of the catheter body and at least one infusion lumen


22


which also extends the entire length of the catheter body. A nose cone


24


which is secured within the distal tip of the catheter body


12


and includes a lumen


26


which aligns with the guidewire lumen


20


in order to form a continuous passage which terminates in a guidewire port


28


in the proximal hub


16


. The nose cone


24


may be tapered, squared, or otherwise formed so that it may facilitate inversion of and trauma to the vein being removed.




The infusion lumen


22


is blocked at its distal end by the nose cone


24


. Thus, fluid which is introduced to the lumen


22


through an infusion port


30


on hub


16


will pass outwardly through the infusion port


32


(see

FIG. 2B

) of the catheter body


12


. In other instances, however, the guidewire lumen may be modified to provide for infusion through the catheter body


12


.




To permit suturing or tying of the venous segment over the distal end of the catheter


10


, a suturing passage


36


is provided transversely through the catheter body and a portion of the nose cone


26


, as best illustrated in FIG.


2


A. In this way, the free end of the venous segment which has been severed from the vein (as illustrated hereinafter) may be attached to the catheter by suturing through the vein and then tying circumferentially around the vein and over the catheter body. Such suturing and tying will provide a very tight connection which is circumferentially uniform over the catheter body. Such uniform attachment permits the application of relatively large axial forces on the vein to permit removal of the vein without tearing the vein. Alternatively, the suture needle may be passed directly through the catheter body


12


without any special provision other than that it be penetrable by a needle or other device to pass the suture therethrough.




Catheter


10


may have a modified distal end including a trough or channel to further facilitate attachment of the free end of the venous segment being removed. Referring to

FIGS. 3

,


3


A,


3


B, a catheter


40


comprises a catheter body


42


with a distal end


44


. A nose cone


46


has an enlarged proximal end relative to the diameter of the remainder of the catheter, and a second enlarged ring


48


is provided proximally of the proximal end of the nose cone. In this way, a trough or channel is created between the proximal end of the nose cone


46


and the distal end of the raised ring


48


. A suturing passage


50


is provided laterally through the raised ring


48


, and permits suturing of the venous segment therethrough. After suturing through the passage


50


, the suture may be used to tie the vein onto the catheter by wrapping and tying in the region of the channel between the nose cone


46


and the raised ring


48


. Catheter


40


will also include a perfusion port


52


.




Referring now to

FIG. 4

, the removal of a saphenous vein SV from a patient's leg L will be described. An incision I


1


is made over the greater saphenous vein in the patient's groin. A second incision I


2


is made over the saphenous vein in the region of the patient's ankle. The incisions are typically surgical cutdowns, and the surgeon will have sufficient access to severe the saphenous vein at the locations I


1


and I


2


. Thus, the length of the venous segment to be removed has now been defined by the two severed ends at the respective locations. After severing the ends, a guidewire GW is introduced through the venous segment to be removed between the locations I


1


and I


2


.




Referring now to

FIG. 5

, after the guidewire GW has been introduced, the pull catheter


40


is introduced over the guidewire from the first location I


1


which has the larger lumen diameter. Catheter


40


is introduced until its distal end reaches the severed portion of the vein near the second location I


2


. At that point, as shown in

FIG. 5A

, suture is passed through suturing passage


50


and wrapped around the vein in the channel form between the nose cone


44


and ring structure


48


. Optionally, saline or other medium may be infused into the lumen of the saphenous vein SV proximal to where the tying has occurred. Such saline infusion can facilitate inversion of the vein while the vein is being removed. After the vein has been removed, saline infusion will be used to help re-invert the vein, test the removed vein for leakage, and the like. In addition to saline infusion, the pull catheter may be provided with a balloon to initially dilate the vein to help free the remote end of the vein from the tissue bed and initiate inversion. The initial dilation is to increase diameter of vessel just proximal to where the tying has accrued so that the fold or inversion can start upon pulling the catheter.




After the free end of the saphenous vein segment to be removed has been tied to the catheter


40


, the catheter is drawn proximally back toward the first incision I


1


, as shown by arrow


60


in FIG.


5


B. As the venous wall is drawn proximally, the vein inverts inwardly along an inversion line EFL.




The saphenous vein SV may continue to be withdrawn by pulling on the catheter


40


. From time to time, however, the withdrawal of the vein may be impeded or stopped by the presence of a venous side branch SB, as shown in FIG.


5


C. In some instances, it may be sufficient to simply pull on the catheter until the side branch SB breaks, typically near its attachment point to the wall of the saphenous vein SV. In other instances, however, it will be desirable to severe the side branch SB to facilitate continued removal of the saphenous vein. One approach for severing the side branches involves using a side branch management tool


70


having a blade


76


, as shown in

FIGS. 5C and 5D

. The side branch management tool


70


may optionally have a transparent window and carry a viewing scope


72


to permit viewing of the inversion line EFL. The presence of the side branches will be quite apparent as they are pulled along the inversion line EFL, as shown in FIG.


5


C. Once problematic side branches are identified, a cutting tool, shown schematically as a blade at


76


in

FIG. 5D

, may be advanced through the side branch management tool


70


to selectively severe the side branch SB.




In addition to side branch management tools having instruments for both viewing and selectively severing side branches, the present invention also provides side branch management tools which are capable of acting “blindly,” i.e., without direct visualization. A first example of such a blind tool is shown in FIG.


6


. Side branch management tool


80


comprises a catheter body


82


having an acorn structure


84


at its distal end and a hub


86


at its proximal end. The tool is adapted to be introduced over a guidewire and includes guidewire lumen


88


at its distal end and a guidewire port


90


on the port


86


. A blunt tip


92


is disposed at the distal end of the acorn structure


84


and an actuable blade


94


(shown in broken line) is adapted to extend radially outwardly and to traverse a generally circumferential path as the acorn


84


is rotated. The acorn


84


is rotatable by manually rotating a wheel


96


in the hub


86


. The general dimensions of the catheter


80


have been set forth previously.




Use of the tool


80


for severing a side branch SB from the saphenous vein SV is illustrated in

FIG. 7A and 7B

. The catheter


80


is introduced over the guidewire from the direction of the second incision I


2


until the leading tip


92


engages the region of the saphenous vein SV which is being inverted, as shown in FIG.


7


A. The distal end


92


is sized so that it can center within the inverting venous wall, allowing the catheter


80


to be advanced in unison with the receding inversion line EFL




When the inversion line EFL reaches a side branch SB, as shown in

FIG. 7B

, the user will feel significant resistance to continue the withdrawal of the vein. If the resistance is sufficiently great, the user can choose to actuate the blade


94


to extend it radially and rotate the blade so that it circumscribes a circumferential path. In this way, the blade will encounter the side branch SB so that it may cut the side branch and free it from the venous segment which is being withdrawn. By properly spacing the blade away from the distal end


92


of the acorn structure


84


, it can be assured that the blade remains behind the venous segment which is being removed so that it will not damage the vein.




An alternative side branch management tool


100


is illustrated in FIG.


8


. Tool


100


includes catheter body


102


having a tubular cutter


104


at its distal end and a proximal hub


106


at it proximal end. Catheter body


102


has a guidewire lumen therethrough, the tubular cutting blade has a serpentine o-castellated structure where recessed portions


110


of the blades are sharpened with the leading portions of the blade


112


preferably being blunt.




The side branch management tool


100


may be used to blindly severe side branches SB from the saphenous vein SV as it is withdrawn, as shown in

FIGS. 9A and 9B

. The catheter


100


is advanced from the second incision I


2


, generally as described above with reference to the other side branch management tools. The saphenous vein SV is withdrawn by catheter


40


until resistance to withdrawal caused by the presence of a side branch SB is felt by the surgeon. The catheter


40


is then advanced and slowly rotated so that the leading edges


112


self-align to blade


104


so that the sharpened recess portions


110


engage the side branch SB, as shown in FIG.


9


A. The blade


104


is then advanced so that the sharpened sections


110


severe the side branch SB, and the pull catheter can then be further withdrawn until the next side branch is encountered or the venous segment is entirely removed.




Referring now to

FIGS. 10-12

, alternative structures for the distal end of the pull catheter of the present invention will be described. In

FIG. 10

, a pull catheter


120


has a distal end


122


with an enlarged or expanded region


124


having an aperture


126


for receiving suture to attach a dissected venous wall. Port


128


is provided for selectively infusing saline or other liquid medium which can aid in re-inversion of the vessel.




In

FIG. 11

, a pull catheter


130


has a distal end


132


which has a radially expanding flare which terminates in a shoulder


134


having a suture-receiving aperture


136


formed therein. A smaller diameter nose cone


138


projects distally from the shoulder


134


which can assist in initiating inversion of the vessel. The ligature knot circumferentially secures the vessel around the smaller diameter nose, pre-disposing the vein to be inverted.




An additional pull catheter


140


is illustrated in FIG.


12


. The pull catheter


140


has a transition region


142


disposed between a main catheter body


144


and a narrow diameter distal extension


146


. Aperture


148


is formed near the transition


142


and is suitable for receiving suture for tying and attaching a dissected end of the vein being removed. The purpose of the distal extension


146


is to assist in management of the vein after it has been removed from the tissue bed. In particular, as the pull catheter of


140


is drawn proximally, e.g. as shown in

FIG. 5B

, in connection with pull catheter


40


, the vein will extend over the distal extension


146


. Thus, when the vein has been fully everted, the distal extension (which will usually have a length approximately equal to that of the main portion of the catheter body


144


) will lie within the length of the removed venous segment. After the pull catheter


140


and removed venous segment are completely removed from the patient, it will be appreciated that the distal extension


146


will provide a linear support for the vein, thus facilitating manipulation of the vein. In particular, preparation of the vein, such as trimming and optional closure of the side branches which remain, will be facilitated. Presence of the venous segment over the distal extension


146


will also help with reinversion of the vein after the interior (which is exposed outwardly while the vein is inverted) has been prepared.




Referring now to

FIGS. 13

to


16


A-


16


C, a presently preferred construction of a side branch management tool similar to tool


80


will be described. The tool


200


comprises a catheter body


202


having a handle


204


at its proximal end and a notched acorn structure


206


at its distal end. The acorn structure


206


is similar to that described previously for side branch management tool


80


, but further includes a stop or notch structure


210


which facilitates engagement and tensioning of the side branch prior to cutting. As shown in

FIG. 14

, the stop or notch structure


210


can engage a side branch SB (shown in broken line) by rotating the acorn structure


206


in the direction of arrow


212


. Once the side branch SB has been engaged and tensioned, a blade


216


can be actuated to extend radially outwardly and rotate in the direction of arrow


218


to seven side branch.




The stop or notch structure


210


illustrated in

FIG. 14

has a number of advantages. In particular, it is relatively smooth and free from abrupt changes or features which would hinder advancement of the catheter


200


through the venous lumen. It will be appreciated, however, that a variety of other structures, such as hooks, pins, loops, or the like, can also be used to selectively engage and tension a side branch in a manner similar to the illustrated stop or notch


210


.




The blade


216


is preferably fully retracted within the notched acorn structure


206


prior to deployment. As shown in FIGS.


15


and


16


A-


16


C, the preferred mechanism for actuating blade


216


will be described. The proximal handle


204


includes a distal button


220


and proximal gripping portion


222


. A user may hold the gripping portion


222


in one hand with the fingers placed over the button


220


so that the button and gripping portion can be selectively closed in the direction of arrows


224


. Such selective closure translates a spirally moved cylinder


226


relative to a fixed sleeve


228


having pins which travel in the grooves. This motion causes the cylinder


226


to rotate about its axis. The cylinder


226


, in turn, is coupled to a rod


230


which extends from the cylinder, through the catheter body


202


, and into an eccentrically mounted cylinder


232


having a radially extending pin


234


, as best seen in FIG.


16


A. The eccentric cylinder


232


is mounted in a ring


236


which is rotatably mounted within the notched acorn structure


206


. As the user actuates the handle


204


to rotate rod


230


, the eccentric cylinder


232


first rotates to radially extend the blade


216


, as shown in FIG.


16


B. Once the cylinder


232


has been rotated 180°, as shown in

FIG. 16B

, the pin


234


engages a shoulder structure


238


on the rotatable ring


236


. In this way, further rotation of the rod


230


causes the eccentric cylinder


232


to rotate the ring


236


, and thus the blade


216


, as illustrated in FIG.


16


C. The blade


216


can be fully rotated to reach the notch


210


and stops travel when it engages rim


240


of slot


242


(

FIG. 14

) which accommodates travel of the blade. In this way, the blade can fully pass through the side branch SB which is held in the stop or notch


210


.




Any of the side branch management tools of the present invention may incorporate viewing scopes, CCD's, or other imaging capability. For example, side branch management tool


200


may optionally be provided with clips


250


(shown in

FIGS. 13 and 14

only) for removably attaching a fiberoptic viewing scope


252


, shown in broken line in FIG.


14


. The side branch management tools, of course, could also be provided with integrated optics or other viewing systems within the scope of the present invention.




Referring now to

FIG. 17

, systems according to the present invention will comprise the pull catheter


10


or


40


, an side branch management tool


80


or


100


, and a guidewire GW. The systems will typically be packaged together in a conventional medical device package B, such as pouch, tube, tray, box, or the like. The components may be packed separately within individual packages within the larger packages B. In all instances, the components are preferably sterilized, either by heat, ethylene oxide, or other conventional sterilant. Kits according to the present invention will further comprise instructions for use IFU setting forth any of the methods described above.




Further, while the invention has been shown and described with reference to an embodiment thereof, those skilled in the art will understand that the above and other changes in form and detail may be made without departing from the spirit and scope of the following claims.



Claims
  • 1. A method for vein removal, said method comprising:exposing first and second spaced-apart locations along vein; transecting the vein at each location; passing a guidewire through a lumen of the vein between the first and the second location; introducing a pull catheter over the wire between the first location and the second location; attaching the vein to a distal end of the pull catheter at the second location; and pulling the pull catheter from the second location to remove vein through the first location, wherein the vein is inverted with an inversion line which moves from the second location toward the first location as the vein is inverted.
  • 2. A method as in claim 1, wherein the vein is a saphenous vein, the first location is in the groin, and the second locator is below the knee.
  • 3. A method as in claim 1 or 2, further comprising:introducing a side branch management tool through the second location over the guidewire and advancing a distal end of the side branch management tool to follow the inversion line; and engaging venous side branches which become exposed on the inversion line with an excision device on the side branch management tool to dissect those side branches from the vein.
  • 4. A method as in claim 2, wherein exposing the first and second spaced-apart locations comprises performing cut downs to surgically expose the vein.
  • 5. A method as in claim 1 or 2, wherein attaching the vein to the distal end of the pull catheter comprises tying the vein around a circumferential band.
  • 6. A method as in claim 3, wherein engaging comprises rotating a structure on the side branch management tool to tension the side branch prior to excision.
  • 7. A method as in claim 3, wherein engaging comprises cutting the side branches with a blade.
  • 8. A method as in claim 3, wherein engaging comprises severing the side branches with an electrosurgical tool.
  • 9. A method as in claim 3, further comprising sealing at least some of the excised side branches.
  • 10. A method as in claim 9, wherein sealing comprises electrocauterizing.
  • 11. A method as in claim 9, wherein sealing comprises clipping, tying, or coiling.
  • 12. A method as in claim 9, wherein sealing comprises applying a tissue sealant.
  • 13. A method as in claim 1 or 2, further comprising removing valves from the vein and re-inverting the vein so that the vein may be used as an implant.
  • 14. An improved method of vein removal, said method being of the type wherein a pull catheter is advanced through a lumen of the vein, attached to the vein, and pulled back to invert the vein, wherein the improvement comprises excising side branches which are exposed on an inversion line of the vein as the vein is inverted.
  • 15. An improved method as in claim 14, wherein excising comprises advancing a tool in a direction opposite to that of the pull catheter and engaging an excision device or tool against the exposed side branches.
  • 16. An improved method of vein removal, said method being of the type wherein a pull catheter is advanced through a lumen of the vein, attached to the vein, and pulled back to invert the vein, wherein the improvement comprises introducing a viewing scope in a direction opposite to that of the pull catheter and viewing an inversion line of the vein as the vein is inverted.
  • 17. An improved method as in claim 16, wherein the improvement further comprises excising venous side branches from the inversion line while the side branches are viewed with the viewing scope.
  • 18. An improved method of vein removal, said method being of the type wherein a pull catheter is advanced through a lumen of the vein, attached to the vein, and pulled back to invert the vein, wherein rhe improvement comprises introducing a side branch management tool in a direction opposite to that of the pull catheter, viewing an inversion line of the vein as it is inverted using a viewing scope on the tool, locating side branches in view of the viewing scope, and excising at least some of the located side branches with an excision device on the tool.
US Referenced Citations (30)
Number Name Date Kind
2779334 Sandborn Jan 1957 A
3045676 Slaten Jul 1962 A
3185155 Slaten et al. May 1965 A
3568677 Nolan et al. Mar 1971 A
3788325 Jacobsen Jan 1974 A
4528982 Wellenstam Jul 1985 A
4793346 Mindich Dec 1988 A
5593418 Mollenauer Jan 1997 A
5667480 Knight et al. Sep 1997 A
5695514 Chin Dec 1997 A
5797947 Mollenauer Aug 1998 A
5817013 Ginn et al. Oct 1998 A
5843104 Samuels Dec 1998 A
5843417 Fogarty et al. Dec 1998 A
RE36043 Knighton Jan 1999 E
5899913 Fogarty et al. May 1999 A
5902315 DuBois May 1999 A
5902316 Mollenauer May 1999 A
5922004 DuBois Jul 1999 A
5928138 Knight et al. Jul 1999 A
5944734 Hermann et al. Aug 1999 A
5968066 Fogarty et al. Oct 1999 A
5993412 Deily et al. Nov 1999 A
6013073 Choukroun Jan 2000 A
6022313 Ginn et al. Feb 2000 A
6030396 Samuels Feb 2000 A
6068639 Fogarty et al. May 2000 A
6077289 Mollenauer Jun 2000 A
6165172 Farley et al. Dec 2000 A
6196968 Rydin et al. Mar 2001 B1
Foreign Referenced Citations (1)
Number Date Country
WO 0045691 Aug 2000 WO