Three‐dimensional intravascular ultrasound evaluation of carina and plaque shift at the distal left main coronary artery bifurcation after treatment with a one‐stent cross‐over technique

Abstract

To assess the geometrical changes in the distal left main coronary artery (LMCA), left anterior descending (LAD), and left circumflex (LCX) that occur after a distal LMCA lesion is treated using a one-stent cross-over strategy. Morphological changes after stent implantation into distal LMCA lesions are not fully understood. We used pre- and postintervention three-dimensional intravascular ultrasound of both the LAD and LCX as well as of the LMCA to evaluate distal LMCA lesions after a 1-stent cross-over strategy. In 38 distal LMCA bifurcation lesions, cross-sectional measurements were performed every 1 mm over a 5-mm segment in the LAD and LCX distal to the carina and over the entire LMCA proximal to the carina. The increase in lumen volume correlated with the increase in external elastic membrane volumes: R = 0.917, P < 0.001, in the LMCA and R = 0.785, P < 0.001, in the LAD with no decrease in plaque volume except at the distal end of the LMCA (P = 0.081) and at the LAD carina (P = 0.11). The LCX lumen area decreased significantly at the LCX carina from 5.9 ± 2.0 mm(2) to 5.3 ± 1.9 mm(2) (P < 0.01); however, the response was variable from a 4.0 mm(2) decrease to a 1.8 mm(2) increase in lumen area. While the change in LCX lumen area at the carina correlated with the change in vessel area (R = 0.791, P < 0.001), there was also a small increase in plaque area at the LCX carina from 6.4 ± 2.9 mm(2) to 6.8 ± 2.9 mm(2) (P < 0.01). LMCA bifurcation lumen changes after cross-over single-stent implantation were determined primarily by conformational changes in vessel geometry.