Apparatus for guiding insertion of surgical instruments into a surgical site while blocking escape of fluids, including gas under pressure, therethrough from the surgical site. A generally Y-shaped housing comprises an elongate instrument guide having a distal end insertable in the surgical site and...http://www.google.co.uk/patents/US5261895?utm_source=gb-gplus-sharePatent US5261895 - Apparatus for guiding surgical instruments into a surgical site and blocking escape of fluids from the site
