Incomplete stent apposition: should we appose or oppose?

ncomplete stent apposition (ISA), also known as stent alapposition, is defined most simplistically as the absence f contact between stent struts and the vessel wall not verlying a side branch. Incomplete stent apposition can ccur at the time of stent implantation—acute ISA—which ight either resolve or persist at follow-up (late-persistent SA). Patients without ISA at the time of stent implantaion but in whom ISA is detected at follow-up are deemed o have late-acquired ISA. Stent underexpansion is defined as he cross-sectional area (CSA) of the stent compared with essel size, either measured as mean reference-lumen CSA r lesion or reference-external elastic membrane CSA (1).