Serial Intravascular Ultrasound Findings After Treatment of Chronic Total Occlusions Using Drug-Eluting Stents

Morphologic changes after chronic total occlusion (CTO) treatment with drug-eluting stents (DESs) have not been assessed in detail. Our aim was to use both baseline and follow-up intravascular ultrasound studies to evaluate the morphologic changes and, especially, the changes in distal vessel size and the effect of subintimal stenting after treatment of CTOs with DES. We analyzed serial follow-up intravascular ultrasound (baseline and follow-up at 9 ± 2 months) after DES implantation into 40 CTOs. Overall, 33 CTOs were treated by the anterograde approach; and 7 were treated by the retrograde approach. Minimum lumen cross-sectional area (CSA) trended toward a decrease from baseline to follow-up (4.8 ± 1.7 vs 4.5 ± 1.7 mm2 , p = 0.10), although the minimum stent CSA (4.8 ± 1.7 vs 4.9 ± 1.7 mm2 , p = 0.26) did not change. The distal reference, but not the proximal reference lumen CSA, increased significantly at follow-up (3.8 ± 2.0 to 5.1 ± 2.3 mm2 , p = 0.0004). Late-acquired stent malapposition was seen in 17 patients (42.5%). In 8 CTOs (20%), a part of the stent was implanted into a subintimal space; in these 8 patients, maximum percent neointimal hyperplasia and minimum lumen area was similar in the subintimal segment compared with the adjacent intraplaque segment. The frequency of late-acquired stent malapposition was similar. In conclusion, after CTO treatment with DES, distal vessel enlargement was detected. Subintimal stenting after recanalization of CTO was not inferior compared with stenting within the plaque in terms of long-term morphologic impact.