A balloon catheter for treatment of a patient's lacrimal system is applied transnasally without the use of a guide wire or a curve retention member. The catheter uses a stainless steel hypotube of sufficient stiffness and column strength to be pushed from the patent's nasal cavity through an opening-formed...http://www.google.co.uk/patents/US7169163?utm_source=gb-gplus-sharePatent US7169163 - Transnasal method and catheter for lacrimal system
