Usefulness of On-line 3D Reconstruction for Stent Implantation

The additional information provided by 3-D reconstruction of intracoronary ultrasound images (ICUS) during stent implantation, was assessed in 8 pts. In total 14 stents were used: 6 Palmaz-Schatz, 3 AVE and 5 Wallstent. The images of all 14 coronary segments encompassing the full stent length and the adjacent reference segments were acquired by using motorized pull-back at constant speed (1 mm/s) and immediately processed in the interventional suite using an automated contour detection algorithm based on acoustic quantification (Figure). Residual percent are stenosis (%AS) of the stented segment, automatically measured on-line after 3-D reconstruction, was compared with ICUS measurements obtained by direct review of the video-tape. In three pts studied before stent implantation on-line 3-D reconstruction facilitated the selection of the stent length by measuring length of dissection and distance between stenosis and left main or diagonal branch. After stent implantation, the absence of stent overlapping in three patients receiving multiple stents and the relationship with side branches could be assessed. The visual information from the 3-D longitudinal views and the on-line measurements triggered additional balloon inflations in 5 pts. The selection of frames and the measurement from tape required longer time than 3-D reconstruction and measurement (4.4 vs 2.35 min, p < 0.001) and resulted in slight underestimation of the residual %AS with 3 pts showing >20% %AS with 3-D not recognized from tape analysis. Conclusion: On-line 3-D reconstruction of ICUS for intracoronary stenting facilitates stent selection, evaluates adequate stent deployment by rapidly and accurately measuring residual intrastent stenosis and detecting its relationship with anatomic landmarks.