Surgery – Instruments – Blood vessel – duct or teat cutter – scrapper or abrader
Reexamination Certificate
1999-07-23
2001-03-27
Buiz, Michael (Department: 3731)
Surgery
Instruments
Blood vessel, duct or teat cutter, scrapper or abrader
C606S190000
Reexamination Certificate
active
06206899
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to methods and instruments for harvesting vascular conduits or vessel sections, such as the saphenous veins, radial arteries and the like from a patient. More particularly, the present invention relates to methods and instruments for creating and maintaining a working space or tunnel over a vascular conduit or vessel in which other surgical instruments can be manipulated to complete the harvest of the vascular conduit or vessel section while minimizing trauma to the vascular conduit or vessel section and the patient.
BACKGROUND OF THE INVENTION
For various surgical procedures, and most commonly for coronary artery bypass grafting (CABG), it is common to remove or “harvest” a vascular conduit or vessel section, such as an artery or vein, from its natural location in a patient's body and to use it elsewhere in the body. In CABG surgery, the vascular conduit is used to establish a bypass between an arterial blood source and the coronary artery being bypassed. Often an artery proximate the heart, such as one of the internal mammary arteries, can be used as the bypass conduit. Alternatively, one or more of the saphenous veins in the legs, or a radial artery in an arm, are used as the vascular conduit, and are sometimes preferred by some surgeons in emergency situations, and where multiple bypass vessels are needed. For patient's requiring multiple bypasses, a surgeon may use the saphenous vein in addition to various arteries to revascularize a patient's heart.
The conventional surgical procedure used to harvest the saphenous vein and the like for use in the CABG surgery, is generally very traumatic to a patient. The procedure involves making a continuous incision in the leg for the full length of the desired vein section in order to provide adequate exposure for visualizing the vein and for introducing surgical instruments to sever, cauterize and ligate the tissue and side branches of the vein. The incision must then be closed by suturing or stapling along its length. Many patients suffer significant complications such as skin loss, infections and impaired healing, saphenous nerve damage, hematomas and may experience lower extremity discomfort for months. The procedure also leaves disfiguring scars, increases patient recovery time and hospital stay and thus adds to the cost of the CABG procedure.
In an attempt to overcome these problems, less-invasive techniques for harvesting vessels have been developed, employing one or two small incisions, generally one at each end of the section of vessel to be removed. Blunt mechanical force is applied by introduction of several surgical instruments of successively larger diameters to first create a working space in the tissue surrounding the vein while separating the vein from the surrounding tissue. Then further multiple instruments are introduced into the generally limited working space to dissect, clip and/or cauterize side branches of the vessel to allow harvesting of the desired section of the vessel. An endoscope generally is required for such a procedure to enhance visualization of the vessel and the surrounding tissue in the rather limited working space, particularly at a distance from the incision.
Even where these less invasive techniques reduce the overall length of the incision, the trauma to the vessel, the surrounding tissue and to the patient can be severe. In particular, the harvesting procedure itself may actually be lengthened and the trauma to the vessel potentially increased due to the number of surgical instruments that are needed for the harvesting procedure, and due to the fact that the instruments are reintroduced through the incision into the limited region between the patient's skin and vein. The trauma to the vessel as well as to the patient is exacerbated by the condition that the patient's skin and associated fat globules and tissue tend to collapse about the saphenous vein. It follows that in each withdrawal and subsequent insertion of a surgical instrument into the region above the vessel may cause added irritation, damage and trauma to the vessel. A nick in the vessel or damage to a side branch of the vessel causes undesirable problems since any damage to the harvested section of vessel must be repaired before it can be used as a graft. The repairs themselves are undesirable since they can lead to subsequent failure of the graft at the point of the damage and repair.
SUMMARY OF THE INVENTION
The goal of the present invention is to reduce the trauma and damage to the vessel being harvested as well as to the patient by providing the capability to more rapidly and less traumatically harvest the vessel. To this end, the invention is used to facilitate the creation of a working space around or above the vessel to be harvested. The working space created by the installation of the invention can then be enlarged if so desired. The enlarged working space can then be fixed and maintained by the invention itself, thereby minimizing the trauma caused by subsequent multiple insertions and withdrawals of additional surgical instruments. In addition, the invention enables a single surgeon to conduct the harvesting procedure.
Generally, the present invention includes an elongated slat assembly having a longitudinal axis and a width dimension transverse to the longitudinal axis, and means associated with the elongated slat assembly for varying the width dimension of the slat assembly. The elongated slat assembly provides a distal dissecting edge which preferably has a pointed tip for facilitating dissection of tissue away from the vessel to be harvested.
The slat assembly preferably includes at least two slats which are laterally translatable relative to each other. In one embodiment, there is an upper and a lower slat having similar cross-sections across their width dimensions. Preferably, the cross-section across the width of the slat assembly, and thus the individual slats, is arcuate. The means for varying the width dimension comprises means for laterally translating the slats relative to each other. Such means for laterally translating includes, for example, a handle at the proximal end of each slat.
To further enable the lateral translation of the assembly, a series of slots are formed in one of the slats and a corresponding series of pins are secured to the other slat with each pin being slidably contained by a corresponding slot. The slots may be formed at a selected angle relative to the longitudinal axis of the slat assembly or, alternately, slots are formed substantially transverse to the longitudinal axis. In the former design, the selected angle is preferably within the range from about 35° to about 90°. In a preferred design, the dissecting retractor includes means for maintaining an enlarged width dimension such that the width is greater than the minimum dimension and such that the width dimension can be fixed while a surgical procedure is conducted. Thus, when expanded, the retractor provides a stable, fixed, and maintained working space during the procedure. In the slot and pin embodiment, each slot includes a lock notch to enable a small longitudinal movement of the pins into respective lock notches to maintain the width dimension of the working space.
Another aspect of the invention includes a stand adjustably secured to respective handles for selectively raising the position of the elongated slat assembly to enlarge the working space above the vessel section to be harvested. Each stand includes a stand slot formed along the length thereof, a foot formed at a base of the stand, and bolt means disposed through the stand slot and threadably secured to the respective handle. In this way, each stand is vertically adjustable relative to the respective handle to maintain the selective raising of the position of the elongated slat assembly when the bolt means is tightened.
A method of using the present invention involves providing an elongated dissecting retractor for dissecting tissue and top and/or side branches from a vessel, such as t
Buiz Michael
Cardiothoracic Systems, Inc.
Fenwick & West LLP
Ngo Lien
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