Predictors and complications of side branch occlusion after recanalization of chronic total occlusions complicated with bifurcation lesions

Abstract

Data on risk factors and periprocedural complications associated with side branch (SB) occlusion after chronic coronary total occlusion (CTO) recanalization are limited. The aims of this study were to identify independent predictors of side branch (SB) occlusion after chronic total occlusion (CTO) recanalization and assess the relationship between SB occlusion and perioperative complications. 245 patients with CTO bifurcation lesions (BFLs) who underwent successful CTO recanalization were included in the study. In the occlusion group, most of the SB occlusions were observed after the implantation of the stents and lack of SB protection was more common. However, there was no significant between-group difference in the angles between the main vessel (MV) and SB. SB occlusion was associated with a higher risk of periprocedural myocardial infarction and a higher composite periprocedural complication rate. Identified as predictors of SB occlusion were no SB protection, use of a dissection-reentry strategy, ostial SB stenosis, and proximal MV stenosis of 50% or more.

Figure 1

SB was obstructed during recanalization of CTO using RDR technique A CTO in the left anterior descending artery with a significant diagonal branch in the proximal cap. (B) Distal filling by contralateral collaterals from the right coronary artery. (C) Retrograde approach through a septal channel. (D) RDR technique crossed to the true lumen. (E) Balloon dilation of the main vessel without SB protection. (F) After implantation of the main vessel stents, the SB was obstructed with TIMI flow grade 1. CTO, chronic total occlusion; RDR, retrograde dissection and reentry; SB, side branch.

Figure 2

Coronary angiogram and quantitative coronary analysis. (A) Chronic total occlusion in the left anterior descending artery with a significant diagonal branch in the proximal cap. (B) The result of two-dimensional quantitative coronary analysis after recanalization. ① Denotes the Prox-Side angle (between the proximal MV and SB); ② denotes the Dist-Side angle (between the distal MV and SB); and ③ denotes the Prox-Dist angle (between the proximal and distal MV. Min D Prox, minimum diameter of the proximal part of the segment; Min D Dist, minimum diameter of the distal part of the segment; Min D Side, minimum diameter of the SB; MV, main vessel; SB, side branch.