Various methods and devices are provided for cutting an opening through tissue. In one embodiment, a tissue-penetrating device is provided and includes a flexible elongate needle shaft that has a distal end with a circumferentially extending tissue-cutting edge formed thereon. A proximal end of the elongate...http://www.google.co.uk/patents/US20090287236?utm_source=gb-gplus-sharePatent US20090287236 - ENDOSCOPIC ROTARY ACCESS NEEDLE
