It should be noted that the outer diameter of the dilator at its constant diameter portion is close to the outer diameter of the flexible tubing 35 so that {HEAD ~ tubing} 35 is guided through {TAIL ~ the wall} of the vessel by the dilator 
is guided through
It should be noted that the outer diameter of the dilator at its constant diameter portion is close to the outer diameter of the flexible tubing 35 so that { HEAD ~ tubing } 35 is guided through { TAIL ~ the wall } of the vessel by the dilator
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 HEAD HEAD HEAD HEAD HEAD OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH