Surgical instrument and method

A method of surgically removing tissue from a surgical site on or in the body of a patient, the method comprising the steps of

• i) introducing to the surgical site a surgical instrument including
• a) an electrically conductive intermediate hollow tube having a central passageway and a cutting window at a distal end thereof;
• b) an inner hollow tube rotatably mounted in the central passageway of the intermediate tube and providing a central suction lumen;
• c) a cutting tool disposed at a distal end of the inner tube such that the cutting tool is accessible through the cutting window of the intermediate tube, the cutting tool including a cut-out defining a tissue-cutting edge;
• d) an electrically conductive outer tube disposed over the intermediate hollow tube and defining a first opening at a distal end of the outer tube that is radially aligned with the cutting window of the intermediate tube, and a first slot that extends from the cutting window across a distal tip of the outer tube;
• and
• e) an electrically insulating layer disposed between the intermediate and outer tubes, the electrically insulating layer defining a second slot in alignment with the first slot in the outer tube;
• ii) rotating the inner hollow tube such as to cause the cutting tool to rotate adjacent the cutting window;
• iii) applying suction to the suction lumen of the inner tube so as to cause tissue to be drawn into the cutting window and contacted by the rotating cutting tool;
• iv) supplying RF energy between the intermediate and outer tubes such that tissue coming into contact therewith is coagulated;
• v) manipulating the surgical instrument so as to cut and coagulate tissue in the region of the cutting window;
• and
• vi) manipulating the surgical instrument so as to coagulate tissue in the region of the first slot in the outer tube.

A blade assembly for use with a surgical instrument and an electrosurgical generator, the blade assembly configured to coagulate tissue at a cutting window and at a distal tip of the blade assembly, the blade assembly comprising:

• a) an electrically conductive outer tube including a distal end that defines a first opening aligned with the cutting window and defines a first slot aligned with the distal tip of the blade assembly;
• b) an electrically conductive intermediate hollow tube defining a central passageway and a distal end, the distal end of the intermediate tube defining a first opening that is aligned with the cutting window, the intermediate tube extending coaxially within the outer tube;
• c) first and second electrical contacts associated with the outer and intermediate tubes respectively, the first and second electrical contacts being electrically connected to respective poles of the electrosurgical generator;
• d) an electrically insulating layer disposed between the intermediate and outer tubes, the insulating layer defining a first opening that is aligned with the cutting window and a first slot that is aligned with the distal tip of the blade assembly;
• e) an inner hollow tube rotatably mounted coaxially within the intermediate tube, the inner tube providing a suction lumen;
• and
• f) a cutting tool disposed at a distal end of the inner tube and accessible to the tissue through the cutting window, the cutting tool defining a cutting edge;
• wherein rotation of the inner tube cuts tissue in the region of the cutting window, and the application of RF energy from the electrosurgical generator to the first and second contacts coagulates tissue at the cutting window and at the distal tip of the blade assembly.