The present invention relates generally to surgical instruments. In particular, the present invention relates to a method and instrument for harvesting a section of a blood vessel from a patient.
In certain surgical procedures, it is necessary to remove a section of a blood vessel from a patient for use in another part of the patient's body or for transplanting into a second patient's body. For example, a section of the saphenous vein may be removed for use in coronary bypass surgery. Previously, it has been necessary to make an incision along the full length of the vein section to be removed. The vein is then freed by severing and ligating the branches of the vein, after which the section of the vein can be removed from the patient. The full length incision must then be closed, for example by suturing or staples. Obviously, the harvesting of the vein in this manner leaves disfiguring scars which are cosmetically undesirable. Additionally, the large incision creates a risk of infection to the patient and may not heal properly, especially with those patients who have poor circulation in their extremities. Such an incision may create a chronic wound which will not heal.
Devices for harvesting a section of a blood vessel without creating a full length incision have been suggested. U.S. Pat. No. 4,793,346 to Mindich discloses a device for harvesting a section of a blood vessel by making only small incisions at opposite ends of the blood vessel section. The device includes a guide rod which fits inside of the vein section and a tube having an inner diameter slightly larger than the outer diameter of the vein section to be harvested. The tube has one or more knife blades at the leading edge which are connected to an electrical supply. The vein section is removed by making the incision sufficiently deep so as to expose the ends of the blood vessel section to be harvested. The blood vessel is cut to expose one end, the guide rod is inserted inside the blood vessel section, and the tube is placed over the end of the blood vessel section to be removed. The tube is then pushed along the blood vessel (into the patient) while rotating the tube to sever the branches of the blood vessel with the knife blades mounted at the leading edge of the tube. Electrical current is supplied to the knife blades to heat the blades and thereby cauterize the ends of the severed branches of the blood vessel. The procedure is continued until the tube has reached the second of the two incisions. The blood vessel is exposed and cut from the patient at the second incision, and the tube is then removed from the patient with the blood vessel section inside of the tube. The blood vessel section is then removed from the tube for further treatment and used as desired.
UK Patent Application GB 20 82 459A discloses a device for harvesting a section of a blood vessel similar to that disclosed in the Mindich patent. Again, two incisions are made, one at each end of the blood vessel section to be harvested. A guide rod is inserted into the blood vessel section through one of the incisions and a tube having a cutting element at its operative end is passed over the blood vessel section and guide rod assembly. The tube is rotated as it passes over the blood vessel section to sever the connecting branches. After the tube has passed the entire length of the blood vessel section, the section is cut away through the second incision and the tube is removed from the patient with the harvested section inside the tube.
The blood vessel harvesting devices of the prior art have certain distinct disadvantages. While the prior art devices eliminate the need for a full length incision to remove the blood vessel segment, two incisions, one at each end of the segment to be harvested, are required in order to remove the blood vessel segment. For patients likely to develop chronic wounds, each additional incision increases the risk to the patient, and it is desirable to keep such incisions as close to the patient's trunk as possible and to minimize the number and size of such incisions. Additionally, the prior art devices do not allow for the viewing of the dissection of the blood vessel segment. The physician operating the removal device is unable to see the progression of the dissection and must rely on the guide rod inserted within the blood vessel to guide the cutting instrument in the proper direction. The inability to view the dissection directly increases the risk of damaging the blood vessel segment and the risk of causing injury to the patient.
In addition, it is critical that the segment of blood vessel being harvested is handled with great care since it is destined for reuse (e.g., as an arterial bypass). The blind insertion of a guide rod into the blood vessel damages and likely destroys the endothelium of the vessel. The prior art devices also have the disadvantage of being unable to adequately close off severed branches of the blood vessel and thus are unable to adequately control bleeding. As a result, the patient suffers greater blood loss than is necessary. The prior art devices also may remove more tissue than is necessary because the size of the cutting device is not readily adaptable to changes in the size of the blood vessel.
There is a need for an efficient and effective means for harvesting a section of a blood vessel from the body of a patient. Specifically, there is a need for a device that does not require insertion of any component within the vessel being harvested, and that allows direct viewing of the dissection of the blood vessel segment while at the same time minimizing the size of the incision into the patient's body. Such a device would allow the physician to be much more precise in this procedure, minimize the risk of the patient developing a chronic wound that will not heal, minimize the amount of scarring to the patient's body and maintain the internal integrity of the blood vessel being harvested.