{HEAD ~ The invention} also relates {TAIL ~ an improved technique} of performing surgery through a flexible surgical port extending into the thoracic cavity and to an improved obturator for installing a flexible trocar tube or cannula which provides the surgical port 
relates
{ HEAD ~ The invention } also relates { TAIL ~ an improved technique } of performing surgery through a flexible surgical port extending into the thoracic cavity and to an improved obturator for installing a flexible trocar tube or cannula which provides the surgical port
HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH