An apparatus and method for forming and enlarging percutaneous penetrations comprises an elongate dilation member which receives an elongate expansion member in an axial lumen thereof. The dilation tube includes a tubular braid which usually comprises a mesh of non-elastic filaments which are radially...http://www.google.es/patents/US6080174?utm_source=gb-gplus-sharePatente US6080174 - Trocar system having expandable port
