Changes in Left Main Bifurcation Geometry After a Single-Stent Crossover Technique

Abstract

Background-We assessed geometric changes responsible for acute lumen loss at the left circumflex coronary artery (LCX) ostium after crossover stenting from the left anterior descending coronary artery (LAD) to the left main artery. Methods and Results-Twenty-three left main artery bifurcation lesions with a preprocedural angiographic diameter stenosis Ͻ50% at the LCX ostium were evaluated using prestenting and poststenting intravascular ultrasound pullbacks from both the LAD and the LCX. At the minimal lumen area (MLA) sites within the LCX ostium and at the LCX carina, the lumen, stent, plaqueϩmedia (PϩM), and external elastic membrane (EEM) areas were measured; the EEM eccentricity was calculated at the LCX carina. The change in MLA within the LCX ostium (⌬L), the change in EEM area at the MLA site (⌬V), and the change in PϩM area at the MLA site (⌬P) were calculated. The MLA within the LCX ostium significantly decreased from 5.4 mm 2 (first and third quartiles, 4.3 mm 2 , 7.2 mm 2 ) prestenting to 4.0 mm

Carina Shift Versus Plaque Shift for Aggravation of Side Branch Ostial Stenosis in Bifurcation Lesions

“…8 And Kang et al 11 also found that narrow carina angle between the left anterior descending and the left circumflex coronary artery and wide angle between the left circumflex coronary artery and the left main lesions were associated with a greater lumen area loss at the left circumflex coronary artery ostium. 11 But in our study, we could not find any correlation between bifurcation angle or carina angle and SBo compromise, carina shift, or plaque shift. In our study, the carina angle (angle α) was correlated with MVd lumen volume increase, which suggests that the operators tend to expand the MV stent less aggressively when bifurcation angle is narrow, which may be the mechanism of no significant correlation between angles and SBo compromise.…”

“…[5][6][7] Therefore, recent studies have suggested that carina shift may be a more important mechanism of SBo compromise. [8][9][10][11] Unfortunately, there have been few systemic studies on relative contribution of carina shift and plaque shift using direct evaluation of SB. The aim of our study was to investigate the mechanism of aggravation of SB ostial stenosis after MV stent implantation in coronary bifurcation lesions by volumetric IVUS analysis of both MV and SBo.…”

Impact of plaque type and side branch geometry on side branch compromise after provisional stent implantation: a simulation study

“…Stent implantation over a bifurcation lesion with or without subsequent post-dilation might induce geometrical changes of the SB ostium leading to observations of angiographic SB compromise during the procedure. These geometrical changes appear to be the combination of two effects: (i) the straightening of the MB that stretches the SB, and (ii) the displacement of the carina towards the SB because of stent expansion [7][8][9][10]27 , confirming observations of other numerical studies on single patients 26,28 . Although angiographic images might demonstrate a significant lumen compromise, this is rarely accompanied by a haemodynamically significant compromise, as demonstrated by post-implantation FFR measurements of the SB 7 .…”

“…A potential complication of this procedure is the aggravation of side branch (SB) ostial stenosis after stent implantation in the main branch (MB) 1,2 and the associated increased risk of periprocedural myocardial infarction [3][4][5] . SB ostium compromise after PSB has been attributed to plaque shift from the MB into the SB 6 or to the shift of the carina into the SB [7][8][9][10] . Several potential predictors of SB ostium occlusion after MB stenting, including SB lumen diameter 11 , distal bifurcation angle 5,9,12 , MB calcified plaque 13 , SB plaque length 4 and thickness 11…”

Intravascular ultrasound-guided percutaneous coronary intervention in left main coronary bifurcation lesions: a review

“…The similar findings about lumen loss at the LCx ostium, which occurred after crossover stenting from the distal LMCA into the LAD, were also found in the previous study. 55 The main mechanism involved is carina shift that is associated with a narrow angle between the LAD and the LCx. This concluded that SB ostium compromise was significantly correlated with the carina shift but not with the plaque shift.…”