Longitudinal plaque redistribution during stent expansion.
The purpose of this study was to clarify the 3-dimensional behavior of plaque during coronary stent expansion. Serial intravascular ultrasound (IVUS) studies, preintervention, and poststenting were evaluated in 32 patients treated with a single-balloon expandable tubular stent. External elastic membrane (EEM), lumen, stent, and plaque + media cross-sectional area were measured at 1-mm intervals through the entire stent as well as proximal and distal reference segments 5 mm from the stent edge. Volumetric calculations were based on Simpson's rule. Overall, the plaque + media volume through the entire lesion did not change during stent expansion (218 +/- 51 vs 217 +/- 47 mm3, p = 0.69). However, EEM and lumen volume increased significantly (EEM volume, 391 +/- 84 vs 448 +/- 87 mm3 [p < 0.0001]; lumen volume, 173 +/- 52 vs 231 +/- 54 mm3 [p < 0.0001]). The change in lumen volume correlated strongly with the change in EEM volume (r = 0.85, p < 0.0001), but poorly with the change in plaque + media volume (r = 0.37, p = 0.03). Plaque + media volume decreased in the midstent zone (59 +/- 14 vs 53 +/- 11 mm3, p = 0.0005), and increased in the distal stent zone (40 +/- 11 vs 44 +/- 9 mm3, p = 0.003), but did not change in either the proximal stent zone or reference segments. The mechanism of stent expansion is a combination of vessel stretch and plaque redistribution, translating disease accumulation from the midstent zone to the distal stent zone.
Maehara
A
A
Center for Research in Cardiovascular Interventions, Stanford University Medical Center, California 94305-5637, USA.
Takagi
A
A
Okura
H
H
Hassan
A H
AH
Bonneau
H N
HN
Honda
Y
Y
Yock
P G
PG
Fitzgerald
P J
PJ
D015906:Angioplasty, Balloon, Coronary / Q000379:methods*; D015982:Bias; D002933:Cineradiography; D017023:Coronary Angiography; D003327:Coronary Disease / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy*; D004548:Elasticity; D006801:Humans; D011237:Predictive Value of Tests; D012008:Recurrence; D012720:Severity of Illness Index; D015607:Stents; D016896:Treatment Outcome; D017540:Tunica Media / Q000000981:diagnostic imaging / Q000473:pathology*; D018084:Ultrasonography, Interventional / Q000379:methods*