Patent ID: 8382707

Claim:
A cannula assembly comprising: a cannula having a proximal end, a distal end, an outer surface, a proximal groove in the outer surface at the proximal end, and a distal groove in the outer surface at the distal end, and a lumen extending between the proximal end and the distal end, the lumen adapted to receive a medical instrument therein; a retention mechanism attached to the outer surface of the cannula and having a proximal end secured to the proximal groove of the cannula and a distal end secured to the distal groove of the cannula, the retention mechanism comprising: a first inflatable balloon positioned near the distal end of the retention mechanism; a second inflatable balloon positioned between the proximal end and the distal end of the retention mechanism; and a mid-section extending between the first inflatable balloon and the second inflatable balloon, the mid-section having an outer surface adapted to contact a body wall of a patient when in use; an inlet monolithically integrally formed with the cannula near the proximal end of the retention mechanism, the inlet in fluid communication with the first and second balloons and the mid-section of the retention mechanism; and a fluid conduit fluidly coupling the inlet with the first and second inflatable balloons; and wherein the mid-section is configured such that upon application of an inflation fluid to the inlet, the first and second balloons inflate before the mid-section.