Coronary chronic total occlusion intervention: A pathophysiological perspective

Abstract

Percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) is the last frontier in coronary intervention. PCI of CTO carries multiple advantages, such as significant improvement in symptoms, improvement in abnormal wall motion and left ventricular function and, possibly, increased long-term survival. As of today the procedural success is markedly improved because of technical innovations and is limited to highly experienced operators. To enhance the overall success rate from a worldwide perspective, a thorough understanding of its pathophysiology is critical to further development of newer techniques and technologies. In this review, the author outlines in-depth the evidence that underpins our understanding of CTO pathophysiology and its insight into CTO intervention that incorporates various steps and techniques to cross the lesion.

Lesion characteristics and procedural complications of chronic total occlusion percutaneous coronary intervention in patients with prior bypass surgery: A meta‐analysis

“…The tapered tip stump CTO is more likely associated with a histologically recanalized segment and less likely to have a major side branch. In contrast, the blunt stump CTO is more likely to have a non‐recanalized microcapillary, which means it will be more difficult to open the CTO lesion 26 . In our meta‐analysis, patients with previous CABG undergoing CTO‐PCI have a more blunt stump and proximal cap ambiguity, but the side branch at proximal entry has no significant difference between the two groups.…”

“…In contrast, the blunt stump CTO is more likely to have a non-recanalized microcapillary, which means it will be more difficult to open the CTO lesion. 26 In our meta-analysis, patients with previous CABG undergoing CTO-PCI have a more blunt stump and proximal cap ambiguity, but the side branch at proximal entry has no significant difference between the two groups. The association between CABG and accelerated atherosclerosis progression was clearly elucidated in many studies.…”

Tips and Tricks for PCI of Chronic Total Occlusions – A Review

“…CTO lesions exhibit two types of histological vascular channels: 1) histologically recanalized segments which are endothelialized microchannels (160-230 μm) and are produced utilizing neovascularization. and found in the tapered stump with looser ibrous tissue, and 2) non-recanalized segments which consist of miniature vessels (<100 μm) that pass into the little side branch or the vasa vasorum and are mostly observed in non-tapered or blunt cap [6][7][8].…”

“…A 1F smaller introducer sheath can be connected to a regular 100cm guide catheter which is cut and made short. Removing 10 cm is usually enough [7].…”

Impact of chronic total occlusion lesion length on six-month angiographic and 2-year clinical outcomes

“…However, despite reductions in restenosis due to DES use, clinical outcomes following percutaneous coronary intervention (PCI) in particular remain strongly affected by baseline lesion characteristics, with greater coronary artery lesion length being associated with poorer prognosis after PCI[ 2 – 5 ].Additionally, despite remarkable progress in the development of DESs, as well as in the development of special devices and techniques for chronic total occlusion (CTO) PCI, procedural success rates in CTO patients are still lower than those in non-CTO patients, with long term outcomes in the former also thought to be affected by baseline lesion characteristics as well as other clinical risk factors[ 6 ].It should be noted, however, that lesion characteristics such as the development of collateral vessels differ between CTO and non-CTO patients. As such, risk factors or predictors of adverse intervention-related outcomes in CTO patients may differ from those associated with non-occlusive disease intervention [ 7 ].Despite this, there have yet to be any definite findings regarding lesion characteristic-based predictors of CTO PCI outcomes, especially in the DES era.…”