A surgical apparatus includes an instrument having an operative zone defined thereon for physical engagement with a patient's body tissue. The instrument has a foraminous outer shell disposed in the operative zone. The foraminous outer shell has a multitude of relatively uniformly dispersed, small perforations...http://www.google.fr/patents/US6203517?utm_source=gb-gplus-shareBrevet US6203517 - Minimization of transport of cancer cells
