Apparatus and method for dissecting tissue layers

A method for creating a working space in a patient's tissue comprising the steps of:

• providing an apparatus including:
• a cannula defining a longitudinal axis, and having a bore extending therethrough, wherein the cannula includes a distal segment having a tapered portion extending inwardly towards the longitudinal axis;
• an obturator configured and dimensioned for insertion into the bore of the cannula such that the obturator is extendible beyond a distal most end of the cannula, the obturator including a distal segment having a tapered portion corresponding in configuration to the tapered portion of the cannula;
• a balloon having an elongate neck and an interior space in communication with the neck, wherein a portion of the neck is positioned between the tapered portion of the cannula and the tapered portion of the obturator to form a substantially fluid tight seal;
• and
• an inflation lumen operatively coupling the interior space with a source of fluid;
• folding the balloon inwardly towards the obturator;
• rolling the balloon inwardly towards the obturator to form a pair of rolls positioned adjacent the obturator;
• making an incision in the patient's skin;
• introducing the cannula and obturator into the incision;
• advancing the cannula and the obturator to a desired location within the tissue;
• and
• inflating the balloon such that the inflated balloon dissects the tissue and defines the working space.