RADIOFREQUENCY 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 into a longitudinally extending side aperture formed in the side of the cannula, near its distal end. An electrosurgical stylet slidably fits inside the inner lumen. At the distal end of the stylet is an electrosurgical electrode capable of ablating tissue and permitting advancement of the system into a patient's body. The electrode, in an expanded deployed configuration, can be wider than the maximum transverse dimension of 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 tube having a central axial bore which communicates with an orifice in the side of 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 aperature of the cannula. In use, the stylet with the cannula disposed about it is advanced into the patient's tissue, using electrosurgical ablation, until the side aperture of the cannula is disposed adjacent a desired site within the patient. The stylet can then be withdrawn from the cannula providing access through the inner lumen of the cannula to the tissue at the desired site.