Tissue Dissection Method

A method for endoscopic harvesting of a selected segment of a blood vessel using an elongated cannula having a rigid tip on a distal end thereof for bluntly dissecting tissue, the method comprising:

• forming an incision in skin overlying the vessel to expose the vessel;
• sealing the incision and insufflating a perivascular region adjacent the vessel near the incision with fluid under pressure;
• advancing the rigid tip of the cannula along the segment of the vessel to dissect tissue under insufflation in response to contact with the rigid tip and to separate the vessel from surrounding tissue to form a cavity of selected dimensions adjacent the vessel along the selected segment thereof;
• selectively expanding the dimensions of the cavity adjacent the vessel along the selected segment thereof;
• occluding and cutting side branches from the vessel along the selected segment thereof;
• and
• sealing and cutting the vessel at ends of the selected segment thereof for removal from the cavity through the incision.

A method for endoscopic harvesting of a segment of a blood vessel using a rigid elongated cannula having a distal end and a rigid element disposed thereat for bluntly dissecting tissue, the method comprising:

• forming an incision in skin overlying the vessel to expose the vessel;
• inserting the distal end of the cannula in the incision adjacent the exposed vessel;
• advancing the distal end of the rigid elongated cannula to position the rigid element near the vessel along the course thereof for bluntly dissecting tissue away from the segment of the vessel by the rigid element to separate the vessel from surrounding tissue to form a cavity adjacent the segment of the vessel;
• insufflating the cavity with fluid under pressure;
• occluding and cutting side branches from the segment of the vessel;
• and
• cutting the vessel at ends of the segment of the vessel for removal thereof from within the cavity.

A method for harvesting of a segment of a blood vessel using a rigid elongated cannula having a distal end and a rigid element disposed thereat for bluntly dissecting tissue, the method comprising:

• forming an incision in skin overlying the vessel to expose the vessel;
• insufflating a perivascular region adjacent the vessel near the incision with fluid under pressure;
• advancing the distal end of the rigid elongated cannula to position the rigid element near the vessel along the course thereof for dissecting tissue away from the segment of the vessel by the rigid element to separate the segment of the vessel from surrounding tissue to form a cavity adjacent the segment of the vessel;
• selectively expanding the dimensions of the cavity adjacent the segment of the vessel;
• occluding and cutting side branches from the segment of the vessel;
• and
• cutting the vessel at ends of the segment of the vessel for removal from within the cavity.

A method for dissecting an elongated cavity in tissue along a selected course in the body of a patient using a cannula having a tissue-dissecting rigid tip at a distal end thereof and having a balloon attached to an exterior wall of the cannula at least near the distal end thereof and including an endoscope disposed within the cannula for visualization of tissue in proximity of the tip, the method comprising the steps of:

• forming an initial incision and bluntly dissecting an initial cavity at a location in the body of the patient;
• inserting the rigid tip at the distal end of the cannula in the initial incision and advancing the rigid tip at the distal end of the cannula through tissue for separating the tissue in contact with the rigid tip along the selected course as visualized through the endoscope disposed within the cannula to form a cavity in tissue extending from the incision along the selected course;
• selectively inflating the balloon to expand the cavity formed in tissue by the rigid tip;
• and
• selectively deflating the balloon within the expanded cavity to facilitate advancing the cannula and rigid tip through tissue to extend the cavity within the tissue.

A method for harvesting a segment of a vessel in the body of a patient using a cannula having a tissue-dissecting rigid tip at the distal end thereof and having a balloon attached to an exterior wall of the cannula at least near a distal end thereof and including an endoscope disposed within the cannula for visualizing tissue in proximity of the tissue-dissecting rigid tip, the method comprising the steps of:

• forming an initial incision and bluntly dissecting an initial cavity at a location in the body of a patient near the vessel;
• inserting the tissue-dissecting rigid tip at the distal end of the cannula into the incision and advancing the rigid tip on the distal end of the cannula for separating the tissue in contact with the tissue-dissecting rigid tip along the segment of the vessel as visualized through the endoscope;
• selectively inflating the balloon to expand the cavity formed in tissue by the tissue-dissecting rigid tip along the segment of the vessel;
• selectively deflating the balloon within the expanded cavity to facilitate advancing the cannula and tissue-dissecting rigid tip within the expanded cavity formed in tissue by the rigid tip along the segment of the vessel;
• and
• selectively manipulating connecting tissue along the segment of the vessel as visualized through the endoscope to isolate the segment of the vessel for harvest from within the cavity in the body.

A method for harvesting a selected segment of a blood vessel using an elongated cannula having a blunt distal end, the method comprising:

• activating the blunt distal end of the cannula through tissue along the course of the selected segment of the blood vessel to be harvested to bluntly dissect tissue in response to contact with the blunt distal end and to separate the vessel from surrounding tissue to form an elongated cavity adjacent the vessel along the selected segment thereof;
• endoscopically visualizing through the distal end within the cavity the dissection of tissue by the blunt tip from the selected segment of the blood vessel;
• removing the cannula from the elongated cavity;
• and then
• severing at least one end of the selected segment of the blood vessel and using the blood vessel as a bypass graft.

A method for harvesting a selected segment of a blood vessel using an elongated cannula having a closed, blunt distal end, the method comprising:

• displacing the blunt distal end of the cannula to a first location along the selected segment of the blood vessel to bluntly dissect tissue and separate the vessel from surrounding tissue and form a cavity;
• expanding an inflatable member mounted near the distal end of the cannula to expand the dimensions of the cavity at the first location;
• displacing the distal end of the cannula to a second location along the selected segment of the blood vessel to bluntly dissect tissue and separate the vessel from surrounding tissue and increase the length of the cavity;
• and
• expanding the inflatable member to expand the dimensions of the cavity at the second location.

A method of harvesting a selected segment of a blood vessel using an elongated cannula having a blunt distal end, the method comprising:

• forming an incision in the skin overlying the blood vessel;
• dissecting through subcutaneous tissue to expose the blood vessel and form a cavity thereabout;
• forming a gas tight seal in the incision;
• infusing gas through the gas tight seal to expand the cavity formed around the blood vessel;
• and
• inserting the elongated cannula through the gas tight seal and advancing the blunt distal end through the tissue surrounding the blood vessel for dissecting tissue to form the cavity along the blood vessel.