Following Cartoid neck artery surgery (left side) to remove plack, 70% blockage has been found by an ultrasound test, 10 months after surgery. Blockage may be scare tissue. Just had a CTscan of artery and head awaiting results. Not sure what to do? Correctly action (Stent, artery repair or bypass) could result in more scare tissue formation later. Also, don't know if current blockage (if scare tissue) will continue or stopped forming. My right side Cartoid neck artery about 35 - 50% blockage. Not sure what to do?