Patent Publication Number: US-2010121362-A1

Title: Vessel support device and method of vessel harvesting

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 11/974,922, filed on Oct. 16, 2007, which claims priority under 35 U.S.C. § 119 to U.S. Provisional Patent Application Ser. No. 60/852,020, filed on Oct. 16, 2006, the entire contents of each of which are hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to biomedical systems and methods. More specifically, the invention relates to systems and methods for harvesting a vessel section. 
     BACKGROUND 
     Heart disease, specifically coronary artery disease, is a major cause of death, disability, and healthcare expense in the United States and other industrialized countries. A common form of heart disease is atherosclerosis, in which the vessels leading to the heart are damaged or obstructed by plaques containing cholesterol, lipoid material, lipophages, and other materials. When severely damaged or obstructed, one or more of the vessels can be bypassed during a coronary artery bypass graft (CABG) procedure. CABG surgery is performed about 350,000 times annually in the United States, making it one of the most commonly performed major operations. 
     To prevent rejection, the graft material is preferably a blood vessel harvested from elsewhere within a patient&#39;s body. The most frequently used bypass vessel is the saphenous vein from the leg. Because the venous system of the leg is redundant, other veins that remain within the patient&#39;s leg are able to provide return blood flow following removal of the saphenous vein. 
     Various methods have been used to harvest the saphenous vein. Until recently, the typical procedure involved making a single long incision that overlies the entire length of the vein, extending from a patient&#39;s groin to at least the knee and often to the ankle. This method results in substantial postoperative pain, with patients frequently complaining more of discomfort at the site of the leg vein harvesting than of pain from their CABG surgery wound. In addition, such an extensive incision site is subject to infection and delayed healing, especially in patients with poor circulation, which not infrequently accompanies coronary artery disease. The disfiguring scar from such a large incision is also of concern to some patients. 
     Less invasive procedures are preferred, and surgical devices and techniques now exist that allow the saphenous vein to be harvested through one or more small, transverse incisions along the length of the vein, generally using an endoscope. Endoscopic procedures yield reduced wound complications and superior cosmetic results compared with traditional methods of vein harvesting. However, this procedure requires considerable manipulation of the vein, has a high conversion rate when visualization is obscured by bleeding or the procedure is taking too long and often requires stitches to repair the vein following harvest. Further, it is generally tedious, time consuming, and relatively complex, requiring extensive accessory equipment and a substantial learning curve for the surgeon. 
     SUMMARY 
     Some embodiments of the invention provide a system for harvesting a section of a vessel from surrounding tissue. The system can include a cutting device adapted to surround the vessel along the section of the vessel and adapted to be moved along the section of the vessel in order to cut the tissue around the vessel. The system can also include a catheter adapted to be inserted into the section of the vessel in order to support the vessel as the cutting device is advanced over the vessel. The system can further include a cannula adapted to be coupled to the vessel and adapted to receive the catheter as the catheter is inserted into the section of the vessel. 
     According to a method of the invention, a section of a vessel can be harvested from surrounding tissue by making a first incision at a proximal end of the section of the vessel, and making a second incision at a distal end of the section of the vessel. The method can include inserting a cannula into the proximal end of the vessel, and securing the proximal end of the vessel to the cannula. The method can also include inserting a catheter through the cannula and into the section of the vessel, and orienting a cutting device coaxially with the cannula and the catheter. The method can further include advancing the cutting device over the cannula, the catheter, and the section of the vessel in order to core out the section of the vessel and a portion of the surrounding tissue. 
     One embodiment of the invention provides an intravascular balloon catheter for use in supporting a section of a vessel being harvested from surrounding tissue with a cutting device. The catheter includes a balloon with a proximal end and a distal end, the proximal end being plugged and the distal end including a routing neck. The balloon is adapted to be inflated in the vessel in order to support the vessel as the cutting device is advanced along the vessel. The catheter also includes a stylet coupled to the routing neck of the balloon. The stylet includes a flexible tip and a coiled wire adapted to navigate through the vessel in order to position the balloon in the section of the vessel. 
     Another embodiment of the invention provides a cannula for use in harvesting a section of a vessel. The cannula includes a distal tip adapted to be inserted into and secured to a proximal end of the section of the vessel. The cannula also includes a valve adapted to prevent fluid flow out of the proximal end of the section of the vessel, with the valve positioned in a proximal end of the cannula. The cannula further includes a tension-coupling member adapted to be coupled to a tensioning device, with the tension-coupling member being coupled to the proximal end of the cannula. The tension-coupling member includes at least one groove adapted to receive at least one raised bump of a tensioning device member adapted to be coupled to a tensioning device. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an illustration of a system for harvesting a vessel section in accordance with embodiments of the invention; 
         FIGS. 2A-2B  are flow diagrams of vessel harvesting methods in accordance with embodiments of the invention; 
         FIGS. 3A-3D  are illustrations of a roll-out intravascular sheath for harvesting a vessel section in some embodiments of the invention; 
         FIGS. 4A-4F  are illustrations of a one piece intravascular catheter balloon and stylet for harvesting a vessel section in some embodiments of the invention; 
         FIGS. 5A-5E  are illustrations of a cannula and tensioning device member for use in harvesting a vessel section in some embodiments of the invention; 
         FIG. 6  is an illustration of an insertion device for a flow delivered tethered balloon for use in harvesting a vessel section in some embodiments of the invention; 
         FIGS. 7A-7C  are illustrations of vessel support devices for use in harvesting a vessel section in some embodiments of the invention; 
         FIG. 8  is an illustration of a vein illumination device for use in harvesting vessel sections in some embodiments of the invention; 
         FIG. 9  is an illustration of a catheter guide for use in harvesting vessel sections in some embodiments of the invention; 
         FIG. 10  is an illustration of a hemostatic control method for use in harvesting vessel sections in some embodiments of the invention; and 
         FIG. 11  is an illustration of a vessel location and hemostasis method for use in harvesting vessel sections in some embodiments of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless specified or limited otherwise, the terms “mounted,” “connected,” “supported,” and “coupled” and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, “connected” and “coupled” are not restricted to physical or mechanical connections or couplings. 
     The following discussion is presented to enable a person skilled in the art to make and use embodiments of the invention. Various modifications to the illustrated embodiments will be readily apparent to those skilled in the art, and the generic principles herein can be applied to other embodiments and applications without departing from embodiments of the invention. Thus, embodiments of the invention are not intended to be limited to embodiments shown, but are to be accorded the widest scope consistent with the principles and features disclosed herein. The following detailed description is to be read with reference to the figures, in which like elements in different figures have like reference numerals. The figures, which are not necessarily to scale, depict selected embodiments and are not intended to limit the scope of embodiments of the invention Skilled artisans will recognize the examples provided herein have many useful alternatives and fall within the scope of embodiments of the invention. 
     As used in this specification and in the appended claims, the terms “distal” and “proximal” are with reference to the operator when the device is in use. 
       FIG. 1  illustrates a vessel harvesting system  300  according to some embodiments of the invention. The system  300  can include a catheter  310 , a rod  320 , a handle  330 , and a tubular cutting device  340 . The system  300  can also include a guidewire and can be used in conjunction with a hemostatic control method for treating severed branch vessels. 
     The catheter  310  and the guidewire can be constructed of a suitable biocompatible materials or combinations thereof, for example, a polymer, stainless steel, nitinol, composites, etc. The lengths of the catheter  310  and guidewire can be roughly determined by the length of the vessel section to be harvested. The rod  320 , the catheter  310 , and/or the guidewire can be coated with a lubricious, slippery material. For example, the catheter  310  can be coated with a slippery material to decrease friction between the catheter  310  and the vessel to ease passage of the catheter  310  into the vessel and decrease the possibility of damaging the vessel interior. The coating can be, for example, a hydrogel coating, polyacrylamide, polyethylene oxide, Teflon, parylene, etc. The coating can also contain one or more biological agents, such as an anticoagulant or an antithrombogenic agent to reduce clotting inside the vessel during the harvest procedure. In one embodiment, the anticoagulant can be heparin. 
     In some embodiments, the coating can contain one or more vasoactive agents or drugs, such as vasodilative agents or drugs and/or vasoconstrictive agents or drugs. Examples of a vasodilative drugs include, but are not limited to, a vasodilator, an organic nitrate, isosorbide mononitrate, a mononitrate, isosorbide dinitrate, a dinitrate, nitroglycerin, a trinitrate, minoxidil, sodium nitroprusside, hydralazine hydrochloride, nitric oxide, nicardipine hydrochloride, fenoldopam mesylate, diazoxide, enalaprilat, epoprostenol sodium, a prostaglandin, milrinone lactate, a bipyridine and a dopamine D 1 -like receptor agonist, stimulant or activator. Examples of vasoconstrictive drugs include, but are not limited to, a vasoconstrictor, a sympathomimetic, methoxamine hydrochloride, epinephrine, midodrine hydrochloride, desglymidodrine, and an alpha-receptor agonist, stimulant or activator. In one embodiment, vasoactive agents or drugs can be administered via one or more bolus injections and/or infusions or combinations thereof The injections and/or infusions can be continuous or intermittent. The injections and/or infusions can be made directly into the vessel section to be harvested. 
     In one embodiment, the catheter  310  is strong enough to receive the rod  320  within a lumen of the catheter  310  and has an outer diameter smaller than the narrowest inner diameter of the vessel to be harvested. The catheter  310  can include one or more lumens. In one embodiment, the catheter  310  can include one or more fluid openings fluidly connected to one or more lumens for delivering or introducing fluids into one or more portions of the vessel to be harvested. The one or more lumens can be fluidly coupled to one or more fluid sources. For example, one or more fluids can be introduced from one or more fluid sources into the vessel to be harvested through the one or more fluid openings prior to removing the catheter  310  from the harvested the vessel. One or more fluids also can be introduced into the vessel through the one or more fluid openings while introducing the catheter  310  into the vessel to be harvested. In one embodiment, suction or a negative pressure can be introduced into the vessel through the one or more fluid openings. For example, suction can be provided from a suction source coupled to the one or more lumens which, in-turn, are coupled to the one or more fluid openings to draw and hold the vessel to be harvested to the catheter  310  while advancing the cutting device  340  over the vessel and along the catheter  310 . 
     In one embodiment, the catheter  310  can include one or more balloons, distensible members and/or inflatable members fluidly coupled to one or more lumens. Following placement of the catheter  310  into the vessel section to be harvested, one or more inflatable members can be inflated via a gas or liquid, thereby securing the vessel to the catheter  310 . The gas or liquid can be, for example, air, carbon dioxide, or saline. The one or more inflatable members can be inflated while advancing the cutting device  340  over the vessel and along the catheter  310 . 
     In some embodiments, a balloon catheter  310  that provides vessel support can also provide a centering function. The balloon catheter  310  can include one or more inflatable structures or elements that can be alternately inflated and deflated. The inflatable structure or structures can expand into the lumen of an inner or outer tubular member of the cutting device  340 . The expansion can force the vessel and the tissue surrounding it into the center of the member to thereby center the cutting element  340  on the vessel. The structure or structures can be inflated to center the vessel and then the cutting element  340  used to cut the tissue adjoining the vessel. The structure or structures can then be deflated to advance the cutting device  340  along the vessel. After advancing the cutting device  340 , the structure or structures can again be inflated and the cutting element  340  can be used to cut the tissue around the vessel. The process of incrementally inflating, cutting, deflating, and advancing can be repeated until the entire section has been excised. In one embodiment, the structure or structures can be inflated the entire time the cutting element  340  is advanced along the vessel. 
     The rod  320  can be an appropriate rigid biocompatible material, for example stainless steel or a rigid polymer. In one embodiment, the rod  320  is long enough to extend beyond at least the proximal end of the vessel section to be harvested and to be attached to the handle  330 . 
     The handle  330  can be constructed of stainless steel; however, other appropriate materials such as other metals and/or suitable polymers can be used. A proximal end of the catheter  310  can be removably attached to the handle  330 .  FIG. 1  illustrates a taper fitting  312  on the proximal end of the catheter  310  that slips over a complementary taper fitting  332  on the distal end of the handle  330  and secures the catheter  310  to the handle  330 . Other fittings, for example, a screw fitting, can also be used. In an alternative embodiment, a proximal portion of the catheter  310  can instead be attached to a proximal portion of the rod  320  after the rod  320  has been inserted into the catheter  310 . The catheter  310  can also attach to the proximal or mid-portion of the handle  330  and the vessel can attach to the distal end of the handle  330 . 
     The handle  330  can include a cavity  334  within which a proximal portion of the rod  320  is received. The cavity  334  can be contained within the handle  330 , as shown in  FIG. 1 . Alternatively, the cavity  334  can extend through the handle  330 , allowing the length of the portion of the rod  320  that extends from the handle  330  to be variable. A setscrew or other appropriate device can be used to secure the rod  320  within the cavity  334 . 
     Alternatively, a vessel cannula  851  (as shown and described with respect to  FIGS. 5A-5D ) can be secured to the vessel. The catheter  310  can be passed through the cannula  851  into the vessel until a small portion remains within the cannula  851 . The catheter  310  can then be inflated or expanded to support the vessel. The expansion in the cannula  851  can help to hold the catheter  310  in place. A tensioning device can then be attached to the cannula  851  to hold the end of the vessel in place while the cutting device  340  is advanced along the outside of the vessel. 
     As shown in  FIG. 1 , the cutting device  340  can include an outer tubular member  110  and an inner tubular member  120 . The outer tubular member  110  can include a cutting element  130  positioned adjacent to its distal end. In some embodiments, the tubular members  110 ,  120  can be advanced independently of each other. The cutting device  340  can include a centering member for centering the vessel within the cutting device  340 . In an alternative embodiment, the cutting device  340  can include a single tubular member  110  having a cutting element  130  positioned adjacent to its distal end. 
     In some embodiments, the cutting device  340  slides over the handle  330 . An inner lumen of the cutting device  340  provides a close-sliding fit for the handle  330 . As shown in  FIG. 1 , the handle  330  extends beyond a proximal end of the cutting device  340 , thereby enabling an operator of the system  300  to grasp a proximal portion of the handle  330  while advancing the cutting device  340  over the distal portion of the handle  330  and over the vessel section to core out the vessel section and tissue adjoining the vessel section. Only a distal portion of handle  330  is shown in  FIG. 1 . 
     With the vessel harvesting system  300 , a hemostatic control method can be used to treat branch vessels severed by the cutting device  340  as it is advanced over the vessel section. Various hemostatic control methods are possible. For example, the hemostatic control method can include the use of a biological sealant or tissue adhesive, for example a platelet gel that is prepared from the patient&#39;s blood and injected or otherwise introduced along the track of the cutting device  340 . Alternatively, or in combination with a biological sealant, a biocompatible or biodegradable tube can be enclosed within the cutting device  340  to be delivered as the cutting device  340  is advanced over the vessel or after the cutting device  340  has completed coring out the vessel and adjoining tissue. A hemostatic control tube can exert pressure on the cut branch vessels and can be either removed or, in the case of a biodegradable tube, left in place to dissolve or degrade over a period of a few days, for example. Alternatively, the exterior of the tubular cutting device  340  can be coated with or deliver a procoagulant material such as thrombin, collagen, a thrombotic polymer, or activating agent such as kaolin or celite to promote clotting of the tissues as the cutting device  340  is harvesting the vessel or after harvesting the vessel. The tubular cutting device  340  can provide a hemostatic control method as it exerts pressure on the cut branch vessels while it remains within the patient&#39;s body. A fluid or gas, e.g. saline or carbon dioxide, can be supplied at the tip of the tool to deliver the fluid or gas into the tissue in the region where the vessel is being harvested. The supplied fluid or gas will accumulate and increase the pressure around the vessel being harvested. The increased pressure can exceed the pressure in the severed vessel branches and provide some hemostatic control by collapsing the vessels and preventing blood from exiting the severed end. A drain can be inserted at the end of the harvesting procedure to deal with any bleeding that does occur. 
     An alternative embodiment of the vessel harvesting system can include a rod  320 , a handle  330  attached to the rod  320 , and a tubular cutting device  340 . This system is similar to system  300  described above, but does not include a catheter  310 . Rather, the rod  320  is inserted directly into the vessel. 
     Yet another embodiment of the vessel harvesting system can include a catheter  310 , a rod  320 , and a tubular cutting device  340 . Again, this system is similar to system  300 , with the exception that no handle  330  is included in this system. Instead of advancing over a handle  330 , the cutting device  340  can be oriented coaxial with the rod  320 . The rod  320 , when fully inserted into the catheter  310  within the vessel to be harvested, can extend far enough outside of the vessel to allow the cutting device  340  to be aligned over the rod  320 . The catheter  310  can be attached to the rod  320  before advancing the cutting device  340  over the rod  320 , the catheter  310 , and the vessel to core out the vessel section and the tissue adjoining the vessel section. 
     Another embodiment of the system can include a rod or guidewire  320  that extends beyond the distal end of the vessel and beyond the proximal end of the handle  330 . The portion of the rod or guidewire  320  that extends beyond the vessel to be excised and the cutting device  340  can be used to anchor the rod or guidewire  320  to a stable object, such as a surgical table or a bedrail. An anchor device can be used to hold the rod or guidewire  320  and a support device can be used to raise or lower the rod or guidewire  320  to a height necessary to be level with the vessel being excised. The anchor and support devices can hold the rod or guidewire  320  steady, straight, and level for the cutting device  340  to follow. In one embodiment, the vessel can be attached to the catheter  310  and the rod and/or the guidewire  320 . In one embodiment, the catheter  310  and the rod or guidewire  320  can be coupled to a tensioning device. 
       FIG. 2A  is flow diagram of a vessel harvesting method according to one embodiment of the invention. In this embodiment, a first incision is made at a point corresponding to a proximal end of the vessel section to be harvested (Block  405 ). A second incision is made at a point corresponding to a distal end of the vessel section (Block  410 ). A guidewire is then positioned within the vessel section (Block  415 ). Alternatively, the guidewire can be inserted into the vessel before the second incision is made. Inserting the guidewire prior to making the second incision can aid in determining the optimal location for the second incision. Once the second incision has been made, the guidewire is positioned such that it extends beyond and outside of the vessel section at both the distal and proximal ends of the section. 
     A catheter is introduced into the vessel section over the previously placed guidewire (Block  420 ). A proximal portion of the vessel section is secured to the catheter (Block  425 ), for example by suturing the vessel onto a barb positioned adjacent to the proximal end of the catheter. Alternatively, the catheter can be introduced into the vessel without a guidewire being previously placed. 
     The guidewire (if present) is withdrawn (Block  430 ), and a rod can be inserted into the catheter to stiffen the vessel section (Block  435 ). Both the catheter and the rod can be attached to a removable handle (Block  440 ). The handle can carry a tubular cutting device, or the cutting device can be introduced over the handle after the handle has been attached to the catheter and rod. An inner lumen of the cutting device provides a close sliding fit for the handle. The tubular cutting device is thus oriented coaxial with the rod and with the vessel section to be harvested (Block  445 ). 
     The cutting device is then advanced over the vessel section to core out the vessel section and tissue adjoining the vessel section (Block  450 ). The cutting device can be advanced by either pushing or pulling the device over the vessel section. Where the cutting device comprises two tubular members, one positioned within the other, the two tubular members can be advanced separately. For example, inner tubular member can be advanced first to hold the vessel and surrounding tissue, while outer tubular member is advanced second to cut the tissue being held by the inner tubular member. The process of incrementally advancing the inner tubular member and then the outer tubular member is repeated until the entire section has been excised. Advancing the inner tubular member ahead of the outer tubular member can protect the walls of the vessel from the cutting element positioned on the outer tubular member. Advancing and rotating the inner and outer tubular members separately can also protect the side branches of the vessel by holding them in place to achieve a clean cut at a sufficient length. The cutting device, for example, can be twisted first in one direction and then in the other direction, or it can be rotated over the vessel. The outer and inner tubular members can be twisted in opposite directions to provide a scissoring action. 
     The cored out vessel section and adjoining tissue are removed from the body of the patient (Block  455 ). Either before or after removing the vessel section and adjoining tissue, a hemostatic control method for branch vessels severed as a result of coring out the vessel section can be introduced through either the first or the second incision. The hemostatic control method can be, for example, a biological sealant, e.g., platelet gel that can be prepared from the patient&#39;s blood and injected or otherwise introduced along the track of the cutting device. The hemostatic control method can also be a thrombogenic substance such as fibrinogen, fibrin and/or thrombin placed in the track left by the cutting device. Alternatively, or in combination with a biological sealant, a biocompatible or biodegradable tube can be enclosed within the cutting device to be delivered as the cutting device is advanced over the vessel or after the cutting device has completed coring out the vessel and adjoining tissue. The tube exerts pressure on the cut branch vessels and can be either removed or, in the case of a biodegradable tube, left to dissolve or degrade over a period of a few days, for example. The space left after the removal of the vessel can also be filled with gauze to provide internal pressure to limit bleeding and absorb blood. The gauze can be removed periodically to check for absorbed blood. Limited blood collected on the gauze indicates the wound bleeding has diminished. 
     Hemostatic control methods are not required for embodiments of the invention as the tubular cutting device itself can exert pressure on the cut branch vessels while it remains within the patient&#39;s body. A drain can be inserted at the end of the harvesting procedure to deal with any bleeding that does occur. The site of the vessel harvesting procedure, e.g., the leg of a patient, can also be wrapped with a compression bandage to limit bleeding. 
     In an alternative embodiment of the invention, a rod can be inserted directly into the vessel. Thus, no guidewire and/or catheter is used. In one embodiment, a proximal portion of the vessel can be attached to the rod rather than to the catheter as described above. The handle is then attached to the rod. 
     In another alternative embodiment, the catheter can be inserted directly into the vessel. Thus, no guidewire or rod is used. In one embodiment, the catheter includes one or more inflatable structures, such as balloons. In yet another alternative method in accordance with embodiments of the invention, no catheter or rod is used; only a guidewire is used. 
     In yet another alternative embodiment, no handle is used. Instead of being carried on the handle, the cutting device is oriented coaxial with the rod. When fully inserted into the catheter within the vessel to be harvested, the rod extends far enough outside of the vessel to allow the cutting device to be aligned with the rod. The catheter can be attached to the rod before advancing the cutting device over the rod, catheter, and vessel assembly. 
       FIG. 2B  is a flow diagram illustrating a vessel harvesting method according to another embodiment of the invention. A first incision is made at a point corresponding to a proximal end of the vessel section to be harvested (Block  405 ). A second incision is made at a point corresponding to a distal end of the vessel section (Block  410 ). A cannula is then inserted into the proximal end of the vessel section, which is located near the knee. The proximal end of the vessel is then secured to the cannula (Block  416 ), for example by suturing the vessel onto a barb or raised portion positioned adjacent to the distal end of the cannula. A balloon catheter is then introduced through the cannula and positioned within the vessel section (Block  421 ). Once positioned, the balloon is inflated to stiffen the vessel section (Block  431 ). A vessel-tensioning device or system is then attached to the cannula to provide a vessel-tensioning force to the vessel section (Block  436 ). 
     A cutting device is oriented coaxially with the cannula, the balloon and the vessel section to be harvested (Block  446 ). The cutting device is then advanced over the vessel section to core out the vessel section and tissue adjoining the vessel section (Block  450 ). The cutting device, for example, can be twisted first in one direction and then in the other direction, or it can be rotated over the vessel. The cored out vessel section and adjoining tissue are removed from the body of the patient (Block  455 ). Either before or after removing the vessel section and adjoining tissue, a hemostatic control method for treating branch vessels severed as a result of coring out the vessel section can be introduced through either the first or the second incision. The hemostatic control method can include, for example, a biological sealant, e.g., platelet gel that can be prepared from the patient&#39;s blood and injected or otherwise introduced along the track of the cutting device. The hemostatic control method can also be a thrombogenic substance such as fibrinogen, fibrin and/or thrombin placed in the track left by the cutting device. Alternatively, or in combination with a biological sealant, a biocompatible or biodegradable tube can be enclosed within the cutting device to be delivered as the cutting device is advanced over the vessel or after the cutting device has completed coring out the vessel and adjoining tissue. The tube exerts pressure on the cut branch vessels and can be either removed or, in the case of a biodegradable tube, left to dissolve or degrade over a period of a few days, for example. The space left after the removal of the vessel can also be filled with gauze to provide internal pressure to limit bleeding and absorb blood. The gauze can be removed periodically to check for absorbed blood. Limited blood collected on the gauze indicates the wound bleeding has diminished. 
       FIGS. 3A-3D  illustrate a rollout intravascular sheath  800  according to one embodiment of the invention. The rollout intravascular sheath  800  can be used to introduce a stabilizing or support device, as discussed in more detail below, into a vessel while protecting the endothelial layer of the vessel. The sheath  800  can provide support to the vessel during a vessel harvesting procedure, e.g., a saphenous vein harvesting procedure. The sheath  800  can be a flexible tube, which is shown not fully extended in  FIGS. 3A-3D . A rigid or semi-rigid inner tube  802  is shown advanced partially through the sliding sleeve  803 . Prior to advancing the tube  802  through the sliding sleeve  803 , the sheath  800  is everted around the edges of the sliding sleeve  803  and one end is fixedly attached or bonded to the sliding sleeve  803 , as shown in  FIG. 3C . The other end of the sheath  800  is fixedly attached or bonded to one end of a wire  801 , as shown in  FIG. 8D . The tube  802  is advanced over the wire  801 , over a portion of the sheath  800  and through the sliding sleeve  803 . The tube  802  is advanced forward into the sheath  800  and into the vessel section to be harvested. Advancement of the tube  802  causes the flexible rollout sheath  800  to unroll as it enters the vein. The wire  801  is free to move with the sheath  800  while the tube  802  is advanced forward thereby allowing the sheath  800  to be unrolled. In one embodiment, there is little to no relative motion, or sliding between sheath  800  and the interior wall of the vessel. Unrolling the sheath  800  within the vessel can minimize damage to the endothelial lining of the vessel as compared to sliding a member against the endothelial lining of the vessel as the member is advanced through the vessel. 
     The sheath  800  can be made of most any biocompatible material, such as polyurethane or ePTFE. In one embodiment, as the clinician advances the tube  802  in the vessel, the sheath  800  material is rolled out. While the tube  802  is advanced in the vessel, the sliding sleeve  803  is held stationary, e.g., just outside the vessel at a point adjacent the site of vessel insertion. The tube  802  is advanced in the vessel to a length that corresponds to the length of vessel that is intended to be harvested. To remove the sheath  800  from the vessel, the wire  801  is pulled back, thereby retracting the sheath  800  and the tube  802  from the vessel and, thereby creating no relative motion between the sheath  800  and the vessel. 
       FIG. 4A  illustrates a one-piece intravascular balloon catheter  900  according to one embodiment of the invention. The intravascular balloon catheter  900  is plugged at its proximal end  902  and includes extended unexpanded balloon material. In one embodiment, the balloon catheter  900  can be approximately 300-500 mm long with a 1.0-2.0 mm diameter when folded and 2.0-6.0 mm diameter when inflated. The balloon catheter  900  can be constructed of a suitable biocompatible material, such as nylon, urethane, polyethylene, or PET. The elongated distal end or routing end  903  of balloon catheter  900  is used to navigate the balloon catheter  900  through the vessel and into place. 
       FIG. 4B  illustrates a stylet  850  that can be placed within the routing neck  903  of the balloon catheter  900  to prevent kinking of the routing neck  903  during insertion within the vessel. In one embodiment, the stylet  850  includes a flexible tip or cap  860  at its distal end, a coiled wire  870 , and a membrane  880 . The flexible tip  860  helps to minimize damage to the vessel wall when navigating around curves. The flexible tip  860  can be tapered to allow easy insertion into vessels of varying size. The proximal end  890  of the stylet  850  can be positioned within the routing neck  903  of the balloon catheter  900 . The distal end  905  of the balloon catheter  900  is advanced over the coiled wire  870  and over the membrane  880 , thereby creating a pressure fit between the distal end  905  of the routing neck  903  and the membrane  880  of the stylet  850 . The pressure fit couples the stylet  850  and the balloon catheter  900  together. The coupled stylet  850  and balloon catheter  900  together can be navigated and routed through the vessel section to be harvested. In one embodiment, as shown in  FIG. 4C , the stylet  850  includes a flexible tip or cap  860  at its distal end and a coiled wire  870 . The proximal end  890  of the stylet  850  is positioned within the routing neck  903  of the balloon catheter  900 . In this embodiment, the distal end  905  of the balloon catheter  900  is positioned within a cavity  891 , thus coupling or securing the distal end  905  of the routing neck  903  and to the stylet  850 , as shown in  FIG. 4D . 
     In one embodiment, a flexible sheath  871  can be placed over the balloon catheter  900 , as shown in  FIGS. 4D-4E . The flexible sheath  871  can be constructed of an elastic or resilient material capable of allowing the balloon catheter  900  to be expanded or inflated and also helping to deflate or collapse the balloon catheter  900  into a low profile configuration similar to its original configuration so that the balloon catheter  900  can be easily removed from the vessel.  FIG. 4E  is a cross-sectional view of a deflated balloon catheter  900  within the flexible sheath  871 . In one embodiment, the balloon catheter  900  is in a folded configuration when it is in a deflated or collapsed configuration within the flexible sheath  871 . 
       FIG. 4F  illustrates a flow delivered tethered balloon catheter  900  according to one embodiment of the invention. This embodiment utilizes a tether  906  coupled to the routing neck  903  to introduce the balloon catheter  900  into a vessel section, e.g., a saphenous vein, during a vessel harvesting procedure. The balloon catheter  900  is sealed at its proximal end  902 . In one embodiment, the distal end  905  of the balloon catheter  900  is attached or bonded to the proximal end of the tether  906 . In one embodiment, the routing neck  903  of the balloon catheter  900  can be approximately 200 mm in length. In one embodiment, the tether  906  can be approximately  500  mm in length. A parachute  912  (in one embodiment, approximately 2-5 mm in diameter) can be coupled or attached to the proximal end of the tether  906 . The parachute  912  can be a cup-shaped component, a lightweight ball, or another suitable structure that is easily carried by fluid flow. The tether  906  can be a thin string, such as thread or suture material. The tether  906  can also be constructed of a material with more stiffness so that it could be pushed into the vein while injecting fluid. 
       FIG. 6  illustrates one embodiment of an insertion device for a flow delivered tethered balloon catheter  900 , as shown in  FIG. 4F . The tether  906  can be introduced into the vessel through a vessel cannula  914  connected to a Y-connector  916  with a Touhy Borst valve  918 . The valve  918  can be tightened as much as possible to prevent backflow of fluid, e.g., blood or saline, but still allow the tether  906  to move. A port  920  of the Y-connector  916  is used to inject fluid, e.g., saline. The cannula  914  is inserted into the proximal end of a vessel section to be harvested, e.g., a saphenous vein section, and sutured into position. For a saphenous vein the proximal end of the section to be harvested is located near the knee. The distal end of the vessel, near the groin region, is opened to allow the parachute  912  to exit the vessel section to be harvested. The tether  906  is injected into vessel at a location near the knee using fluid, such as saline, to carry the parachute  912  from the knee to the groin incision. The balloon catheter  900  is then pulled into position within the vessel at a desired location. After the balloon catheter  900  is inflated, the cutting device is inserted at the knee incision to perform the harvest. The fluid used to advance the parachute  912  can be saline, blood, heparanized saline, or another suitable biocompatible fluid. In one embodiment, one or more fluids can be injected through the port  920  to flush the vessel before, during and/or after insertion of the balloon catheter  900 . In one embodiment, the parachute  912  allows the balloon catheter  900  to be pulled into the vessel by the tether  906 , rather than being pushed into the vessel with a stylet, for example. 
     In one embodiment, the vessel section to be harvested is isolated at its proximal and distal ends. In one embodiment, a saphenous vein section is isolated having a proximal end located approximately near the knee, while the distal end is located at or near the groin region. As shown in  FIGS. 5A-5D , a distal tip  852  of a cannula  851 , can be inserted into the proximal end of the isolated vessel, e.g., a section of saphenous vein. The vessel is then ligated to the cannula  851 . A proximal end  853  of the cannula  851  can include a valve  854  to prevent back flow of fluid, such as blood and/or saline, from the vessel out the cannula  851  end. In one embodiment, the valve  854  is a bileaflet or duckbill valve, as shown in  FIGS. 5A-5D . In one embodiment, the proximal end  853  of the cannula  851  can include a tension-coupling member  855 , as shown in  FIGS. 5C-5D , for coupling a tensioning member to the cannula  851 . In one embodiment, a twist lock mechanism can be used to secure a tensioning device member  861 , as shown in  FIG. 5E , to the cannula  851 . The distal end  862  of tensioning device member  861  is inserted, twisted and locked into place within tension coupling member  855  located at the proximal end  853  of the cannula  851 . In one embodiment, a bayonet fastener mechanism can be used to couple the tensioning device member  861  to the tension coupling member  855 . For example, raised bumps  864  sized to fit within grooves  865  can be used to couple the tensioning device member  861  to the tension coupling member  855 . A tensioning device can be coupled to tensioning device member  861  at its proximal end  863 . 
     Once the vessel is cannulated, the balloon catheter  900  can be routed through the vessel by routing the proximal neck  903  and the stylet  850  through the cannula  851  and through the vessel section to be harvested. Once the balloon catheter  900  is positioned in its desired location within the vessel section to be harvested, the stylet  850  may or may not be removed from the routing neck  903 . Following placement of the balloon catheter  900  within the vessel, the balloon catheter  900  can be inflated through the distal end of the routing neck  903 , which has exited out the distal end of the vessel section. In one embodiment, the balloon catheter  900  is inflated to a diameter of approximately  4  mm. The balloon catheter  900  is semi-rigid when it is inflated, which allows the vessel to still maintain most of its anatomical course. When the balloon catheter  900  is inflated, it is rigid enough to interface with the routing ridge  506 , as discussed above. The routing ridge  506 , in combination with a cutting device having a flexible distal end, allows the cutting device to accurately and precisely navigate the vessel to ensure the harvesting of a viable vessel section, e.g., acceptable for use as a graft in a CABG procedure. 
     The balloon catheter  900  can be constructed of non-compliant or semi-compliant materials, such as PET (polyethylene terepthalate), nylon, Pebax and/or polyurethane, for example. Most commonly, the balloon catheter  900  is folded and wrapped in a collapsed configuration to create a low profile to assist in its insertion into the vessel. The sheath  871  can be a section of tubing made of an elastomer such as silicone and/or modified silicone, such as C-flex, which is silicone modified styrenic thermoplastic elastomer. The sheath  871  can be applied over the top of the balloon catheter  900 . The sheath  871  can expand with the balloon catheter  900  when the balloon catheter  900  is inflated with saline solution, and can return the balloon catheter  900  back to its original low profile when the balloon catheter  900  is deflated. Thus, the sheath  871  assists in an application where the balloon catheter  900  is to be inserted into a vessel with a low profile, inflated, and removed from the vessel with a low profile. 
     By returning the balloon to a low profile after it has been inflated inside a vessel, the amount of damage to the inner vessel walls is greatly reduced during removal of balloon catheter  900 . Non-compliant and semi-compliant balloons are often folded and wrapped so that they have the lowest possible profile until they reach their destination within the vessel. Then once the balloon catheter reaches its desired area, it is inflated. Then in order to remove the balloon catheter from the vessel, the balloon catheter is deflated. However, the balloon catheter may not return to its original low profile shape when deflated. This can be destructive to the inner walls of the vessel as the balloon catheter can have edges created by folds when the balloon catheter is deflated. Therefore, the elasticity of the sheath  871  is used to bring the deflated balloon catheter  900  back to its original profile. 
       FIGS. 7A-7F  illustrate vessel support devices according to various embodiments of the invention. The following discussion discloses alternatives to using the balloon concepts discussed in detail above for vessel support. Specifically, the following discussion discloses ways to provide stabilization or support to a vessel during a harvesting procedure by placing a support member inside the vessel. These alternatives include inserting a rod or dilator into a flexible sheath or coiled tube, using a wire braid that increases in diameter when compressed, a tapered rod or dilator, a rod or dilator with a flexible tip, a tube or dilator having irrigation holes, and a rod or dilator with slippery, lubricious coating, e.g., an Advawax coating or a hydrogel coating. Other lubricious coatings, as discussed above, can be used. These varied concepts all provide a support structure that is placed within the vessel section that is to be harvested, thereby providing the harvesting tool a structure to follow, while preserving the endothelial lining of the vessel. Some of the concepts provide for a small diameter during insertion and removal and a larger diameter during the cutting procedure. Some embodiments create a fluid barrier between the support member and the vessel wall. 
     Inserting a rod or dilator into a flexible sheath or coiled tube can be used to expand the flexible sheath or coiled tube. The flexible sheath or coiled tube can be inserted into the vessel with a smaller diameter, then expanded to a larger diameter with the rod or dilator, thereby achieving the desired diameter and stiffness. The rod or dilator can then be removed from the flexible sheath or coiled tube when it is desirable to have a smaller diameter to remove the flexible sheath or coiled tube from the vessel. The flexible sheath can be an elastomeric tube, approximately the length of the vessel section to be harvested. The flexible sheath can be capable of expanding to the desired diameter when a rod or dilator is inserted. Since the rod or dilator can be slid into the flexible sheath or coiled tube, rod or dilator and sheath materials that create minimal friction are desirable. The coiled tube can be a piece of thin-walled, coiled polymer, such as Teflon, that had a heat set in the coiled configuration. The coil can unwind as the dilator is inserted, thereby expanding to the desired diameter. 
       FIG. 7A  illustrates one embodiment of a dilator  930  that can be placed within the vessel to be harvested. The dilator  930  has a flexible tip  932  which is narrower than the diameter of dilator  930 , e.g., approximately 5 mm. The tip  932  can extend roughly 1 cm from the main body of the dilator  930  and can provide a guide for insertion of the dilator  930  into a vessel section to be harvested. The dilator  930  can be made of a Teflon material so it can slide more easily though the vessel, thereby helping preserve the endothelial lining of the vessel. In one embodiment, the dilator  930  can be inserted through a cannula  914  having diameter large enough to allow the dilator  930  to pass through. One or more fluids as discussed above can be injected through the port  920  to irrigate the vessel before, during and/or after insertion of the dilator  930 . 
       FIG. 7B  illustrates one embodiment of the dilator  930  having one or more holes  933 . The holes  933  allow the user to inject one or more fluids, e.g., saline, through the dilator  930  to create pressure in the vessel thus expanding it outward and making the insertion of the dilator  930  easier. The injection of fluid can creates a fluid barrier between the dilator  930  and the vessel wall to minimize endothelial damage. 
     The end of the vessel can be tied off to retain the added fluid(s), such as saline. Fluid can be added to the vessel to achieve an internal vessel pressure of roughly 50-200 mmHg during insertion and removal of the dilator  930 . In one embodiment, fluid(s) containing one or more medical, biological and/or pharmaceutical agents and/or drugs can be delivered to the vessel before, during and/or after a vessel harvesting procedure. One or more fluids can be delivered via one or more fluid delivery devices, e.g., a syringe or a pressurized fluid reservoir. The vessel can be secured by tying the vessel around features protruding from the side of the dilator. In one embodiment, a needle, for example, can be inserted into the vessel section to be harvested. The needle is then used to fill the vessel section with fluid(s) before, during and/or after insertion of the dilator  930 . In one embodiment, a small pressure relief hole can be created in the vessel section to ensure the vessel is not damaged due to a large internal fluid pressure during the harvesting procedure. In one embodiment, a pressure gauge can be used to accurately monitor the internal pressure of the fluid filled vessel section. 
       FIG. 7C  illustrates a vessel support device  954  including a braided cylindrical structure similar to a vascular stent. In one embodiment, a flexible protective membrane  956  is placed over the vessel support device  954  to protect the endothelial layer by shielding the vessel wall from the wire braid during insertion and removal of the vessel support device  954  during a vessel harvesting procedure. After the vessel support device  954  is inserted into the vessel, one end of the vessel support device  954  is then fixed to the vessel. An insertion tool  958  is inserted within the vessel support device  954  to cause the vessel support device  954  to expand to the diameter of the vessel. 
       FIG. 8  illustrates a vein illumination device according to one embodiment of the invention. As discussed, current vessel harvesting is a tedious, labor-intensive process. Harvesting is often accomplished with an electrosurgical tool to cut away tissues around the vessel to be harvested so as to free the vessel, e.g., from the leg, the chest wall or other body structure. In some harvesting procedures, the location of the vessel has to be repeatedly assessed and verified by the surgeon to be sure to stay clear of the vessel with the surgical tool to avoid damaging the vessel. To prevent bleeding from the vessel or vessel attachment points, side branches of the vessel can be occluded, for example, via clips, sutures, or electrocautery. Therefore, some embodiments of the invention include a method of illuminating the vessel from the inside out to make the location of the vessel readily visible in order to cut around it. Another embodiment involves a catheter-like device within the vessel to act as a guide for an external cutter to harvest the vessel away from the native tissue. A further embodiment controls bleeding from the vessel side branches by dispensing into the side branches a material that occludes and plugs the side branch allowing the branch to be cut without applying clips, sutures, or electrocautery.  FIG. 8  illustrates illuminating a vessel  1100  with an intravenous catheter device emitting light  1102 , e.g., via fiber optics. This illumination is designed to aid visualization of the vessel, e.g., the internal mammary artery (IMA), radial artery, saphenous vein or similar vasculature during cut down to aid in the vessel harvesting procedure. 
       FIG. 9  illustrates an intravenous catheter device  1104  placed within a vessel  1106  to serve as a centering guide for advancing a vessel-cutting device  1108  along the exterior of vessel  1106 . 
       FIG. 10  illustrates a hemostatic control device  1111  according to one embodiment of the invention. Hemostatic material  1110  is shown deployed from the hemostatic control device  1111  positioned within the vessel section to be harvested. In one embodiment, vessel side branches  1112  of the vessel section to be harvested can be occluded or plugged prior to the vessel harvesting procedure. The hemostatic material  1110  can maintain hemostasis without the time consuming process of ligating or cauterizing each branch during a vessel harvesting procedure. The hemostatic material  1110  can be made of UV curable glue or adhesive, a platelet gel material, an expanding hydrogel material, and/or other biocompatible hemostatic material. 
       FIG. 11  illustrates a vessel location and hemostasis device according to one embodiment of the invention. In operation, a hollow guide  1122  is inserted through the chest wall, for example. A distal end of the hollow guide  1116  has a ring/oval magnet  1118  attached. The distal end is placed against vessel exterior  1120  at a target anastomosis location. The hollow guide  1116  is then placed into the vessel  1120 , e.g., an IMA vessel. The hollow guide  1122  has a ring/oval magnet  1124  attached at its distal end. The intravascular hollow guide  1116  is magnetically attracted to extravascular hollow guide  1122  trapping the vessel wall between them. Once the vessel wall between the two guides is penetrated, the rings form a hemostatic seal and the hollow guides  1116  and  1122  now form a continuous channel to pass guidewires, catheters, and/or hemostatic control devices through the vessel wall. 
     It will be appreciated by those skilled in the art that while the invention has been described above in connection with particular embodiments and examples, the invention is not necessarily so limited, and that numerous other embodiments, examples, uses, modifications and departures from the embodiments, examples and uses are intended to be encompassed by the claims attached hereto. The entire disclosure of each patent and publication cited herein is incorporated by reference, as if each such patent or publication were individually incorporated by reference herein. 
     Various features and advantages of the invention are set forth in the following claims.