APPARATUS AND METHOD FOR ACCESSING A BIOPSY SITE

摘要

A system for accessing a desired site within a patient's body includes a cannula defining an inner lumen that opens both forwardly (18) and into a longitudinally extending side aperture formed in the side of the cannula, ne ar its distal end. An electrosurgical stylet slidable fits inside the inner lumen. At the distal end of the stylet is an electrosurgical electrode (28) capable of cutting tissue when at forward opening (18)and permitting advancement of the system into a patient's body. The electrode, in an expand ed deployed configuration, can be wider than the maximum transverse dimension o f the cannula, but it may be deflected toward the center of the stylet so that the electrode fits within the inner lumen of the cannula, permitting the stylet to be inserted and removed through the cannula. An elongate guide tub e having a central axial bore which communicates with an orifice in the side o f the guide tube can be inserted into the inner lumen of the cannula such that the guide tube orifice coincides with the longitudinally extending side aperture of the cannula. In use, the stylet with the cannula disposed about it is advanced into the patient's tissue, using electrosurgical cutting, until the side aperture of the cannula is disposed adjacent a desired site within the patient. The styletcan then be withdrawn from the cannula providing access through the inner lumen of the cannula to the tissue at the desired site.