Septal collateral distal tip injection during retrograde percutaneous coronary intervention for chronic total occlusion

Background The use of collateral channels(CCs)in crossing the occlusion plays a pivotal role in the retrograde PCI approach,but the impact of septal collateral distal tip injection(DTI)on contemporary septal collateral channels(CCs)crossing is still unknown.Methods 264 chronic total occlusion(CTO)cases in which the retrograde approach via septal collateral channels were enrolled after reviewing the coronary angiograms of 1300 patients from Jan 2014 to Dec 2019.This study collected the clinical and angiography data of those patents for analyzing the usefulness of this technology.In addition,a forward multivariable logistic-regression model was applied to identify the independent predictors of CC crossing failure.Results A total of 264 retrograde cases were divided into successful CCs crossing group(n=233,88.3%)and failure group(n=31,11.7%).Univariate statistics showed successful cases had low proportion of collateral channel tortuosity(42.1%vs.67.7%,P=0.011)and JCTO≥3 lesions(68.7%vs.90.3%,P=0.002)while had higher proportion of Werner CC2 collateral(52.8%vs.16.1%,P<0.001).Multivariate statistics found that the use of DTI was not significantly associated with increasing CCs crossing success rate.Twenty cases in success group performed DTI after CCs crossing failure.Conclusions Successful CTO PCI via septal CCs was not enhanced by the use of DTI before CCs attempt.