A cannula arrangement includes an outer tube and an inner tube. The outer tube has a proximal end and a distal end. The inner tube is disposed within the outer tube to define a space between an inner surface of the outer tube and an outer surface of the inner tube. A flexible sealing element is sized to seal the space between the inner surface of the outer tube and the outer surface of the inner tube. The flexible sealing element is connected to a proximal portion of the outer tube. The flexible sealing element has a cantilevered portion that longitudinally extends proximally from the proximal end of the outer tube. The cantilevered portion has an inner surface portion that does not contact the inner tube, and a proximal portion configured to define an interior edge to contact the outer surface of the inner tube.
