A trocar system comprising: a cannula having a working channel to receive surgical instruments therethrough and an outer surface; a stabilization seal for placement on the outer surface of the cannula, the stabilization seal comprising: an inflatable elongate tube having a proximal end, a distal end, a first, inner surface and a second outer surface, the elongate tube having a substantially cylindrical shape; a sealing cuff at the proximal end of the elongate tube for sealing the proximal end of the tube to the cannula; a central region of the elongate tube extending distally from the sealing cuff to the distal end; and a distal-end region of the elongate tube associated with the distal end; characterized in that the central region of the stabilization seal has a first wall thickness and the distal end region has a second wall thickness that is thinner than the first wall thickness and in that, with the stabilization seal coupled to the cannula, the central region forms a first inflatable region formed to expand slightly in a space from the outer surface of the cannula to the inner surface of the elongate tube and the distal end region forms a second inflatable region in a space from the outer surface of the cannula to the inner surface of the elongate tube, the second inflatable region being greatly expandable to form a retention feature. a cannula having a working channel to receive surgical instruments therethrough and an outer surface; a stabilization seal for placement on the outer surface of the cannula, the stabilization seal comprising: an inflatable elongate tube having a proximal end, a distal end, a first, inner surface and a second outer surface, the elongate tube having a substantially cylindrical shape; a sealing cuff at the proximal end of the elongate tube for sealing the proximal end of the tube to the cannula; a central region of the elongate tube extending distally from the sealing cuff to the distal end; and a distal-end region of the elongate tube associated with the distal end; characterized in that the central region of the stabilization seal has a first wall thickness and the distal end region has a second wall thickness that is thinner than the first wall thickness and in that, with the stabilization seal coupled to the cannula, the central region forms a first inflatable region formed to expand slightly in a space from the outer surface of the cannula to the inner surface of the elongate tube and the distal end region forms a second inflatable region in a space from the outer surface of the cannula to the inner surface of the elongate tube, the second inflatable region being greatly expandable to form a retention feature. an inflatable elongate tube having a proximal end, a distal end, a first, inner surface and a second outer surface, the elongate tube having a substantially cylindrical shape; a sealing cuff at the proximal end of the elongate tube for sealing the proximal end of the tube to the cannula; a central region of the elongate tube extending distally from the sealing cuff to the distal end; and a distal-end region of the elongate tube associated with the distal end; characterized in that the central region of the stabilization seal has a first wall thickness and the distal end region has a second wall thickness that is thinner than the first wall thickness and in that, with the stabilization seal coupled to the cannula, the central region forms a first inflatable region formed to expand slightly in a space from the outer surface of the cannula to the inner surface of the elongate tube and the distal end region forms a second inflatable region in a space from the outer surface of the cannula to the inner surface of the elongate tube, the second inflatable region being greatly expandable to form a retention feature.