A spinal needle which has the capability of sealing its opening after withdrawal. A first conventional spinal needle or cannula is used for standard diagnostic or therapeudic use. A second cannula is inserted concentrically into the first needle and includes a dural seal having an absorbable suture extending...http://www.google.es/patents/US5053046?utm_source=gb-gplus-sharePatente US5053046 - Dural sealing needle and method of use
