Trocar cannula assembly and method of manufacture

A cannula assembly comprising:

• a cannula having a proximal end, a distal end opposite the proximal end, and a lumen extending from the proximal end to the distal end along a longitudinal axis, the lumen configured to receive a surgical instrument therein, the cannula comprising:
• a generally tubular cannula body having an exterior surface and a first outer diameter;
• and
• an annular recess formed in the exterior surface of the cannula body adjacent the distal end of the cannula, the annular recess transverse to the longitudinal axis, the annular recess having a second outer diameter smaller than the first outer diameter of the cannula body;
• and
• a sleeve having a proximal end and a distal end, the sleeve disposed around the cannula from adjacent the proximal end of the cannula to the annular recess, the sleeve comprising:
• an elongate tubular body;
• a balloon positioned distal the elongate tubular body;
• and
• an annular ring distal the balloon, the annular ring positioned in the annular recess of the cannula, and the annular ring having a third inner diameter in an undisturbed state, the third inner diameter of the annular ring smaller than the second outer diameter of the annular recess to define an interference fit between the sleeve and the cannula.