System and method for placement of a surgical instrument in a body cavity

An apparatus for facilitating surgery within a body cavity using a cryoprobe having a proximal portion and a probe portion extending therefrom for insertion into the body cavity, comprising:

• a positioning assembly for positioning a distal end of the probe portion within the body cavity at a selected position relative thereto, said positioning assembly having a positioning element which can assume a retracted position to allow insertion of said positioning assembly within the body cavity and a deployed position in which said positioning element is displaced radially outward relative to said retracted position and relative to an axis of the probe portion when the probe portion is inserted in the body cavity, said positioning element capable of contacting an interior surface of the body cavity and adapted to move the probe portion away from the interior surface when said positioning element is deployed;
• a tubular probe sheath with a lumen and a distal end, said distal end of said probe sheath adapted to accommodate and axially restrain the probe portion of the cryoprobe therein;
• and
• an actuator for moving a proximal end of said positioning element relative to said probe sheath to deploy and retract said positioning element, said positioning element being in greater overall proximity to said probe sheath when in said retracted position to facilitate inserting said positioning assembly in the body cavity and diverging to a greater degree when in said deployed position;
• said positioning element being displaceable axially relative to the probe portion to move said distal end of said probe sheath and the probe portion away from the interior surface in an axial direction.