Intimal proliferation after stenting reflected by increased stent-to-vessel cross-sectional area ratio: serial...

Minimizing the extent of neointimal proliferation helps to maintain the maximal vessel lumen after the treatment of stenosis. The present study examined factors influencing the predisposition to neointimal proliferation, which is a consequence of Palmaz-Schatz stenting. Serial intravascular ultrasound examinations of 32 lesions (4 lesions/patient) were performed after stenting and at 6 months follow-up in 8 non-restenotic patients. Vessel, lumen and stent cross-sectional areas (CSA) were measured. Stent-to-vessel CSA ratio at stenting, changes of lumen CSA, vessel CSA and intima CSA (neointimal proliferation) were calculated. Six months after stenting, lumen CSA was reduced corresponding to an increase of intima without change of vessel CSA (without remodeling). Greater stent-to-vessel CSA at stenting was associated with higher neointimal proliferation at follow-up. The proliferative response was the same at all stent edges. Stent CSA was reduced as stent dilation was increased. The stent CSA became smaller but stent shrinkage did not account for late lumen loss. Late lumen loss in stents is the result of neointimal proliferation in cases without restenosis, and a larger stent-to-vessel CSA ratio reflects increased neointimal proliferation, as shown at 6-month follow-up.