The Role for Adjunctive Image in Pre-procedural Assessment and Peri-Procedural Management in Chronic Total Occlusion Recanalisation

Abstract

Non invasive coronary angiography with multislice computed tomography has exquisite sensitivity to detect calcium and even the faintest late contrast filling of the distal vessel. Calcium burden and occlusion length are still valuable markers of duration, complexity and success of the recanalisation procedure. The ability to visualise the vessel also in the occluded segment, especially if calcified, can also help the operator to understand where to pierce the proximal cap in stumpless occlusions and to predict unusual courses, especially in very tortuous arteries. Imaging side by side CT images and angiography during the recanalisation procedure is an established practice in many active CTO laboratories and algorithms for co-registration are designed to overcome the challenges of systo-diastolic and respiratory motion. Intravascular ultrasound is used in almost all cases by the experienced Japanese CTO operators but most of the times its main use is a better identification of the diseased segment after predilatation to ensure complete stent cover and appropriate stent expansion, an application similar to other complex non occlusive lesions. The specificity of IVUS during CTO recanalisation is the identification of the vessel path in stumpless occlusions and the guidance of wire reentry especially during reverse Controlled Retrograde Anterograde Tracking. Optical coherence tomography has limitations in the setting of CTO recanalisation because of the need of forceful contrast flushing to clear blood, contraindicated in the presence of anterograde dissections, and the limited penetration. The variability in the use of both non-invasive and invasive imaging during CTO recanalisation is immense, going from more than 90% in Japan to less than 20% in Europe and intermediate penetration in the USA. Probably the explanation is almost only in availability and cost because all countries see a progressive increase of use suggesting that these methods are becoming an established tool for guidance of CTO recanalisation.

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“…Para implementar la estrategia de revascularización más apropiada, existe un interés cada vez mayor por las valoraciones no invasivas de las lesiones coronarias complejas que a su vez podrían beneficiarse de las técnicas existentes de modificación de la placa 15,16 . Si supiésemos, con antelación, qué pacientes terminarán precisando una AR, no tendríamos que utilizar esta técnica como estrategia de rescate, reduciríamos el tiempo operatorio, el uso de contraste y el número de complicaciones isquémicas.…”

The Role of Multimodality Imaging for Percutaneous Coronary Intervention in Patients With Chronic Total Occlusions

“…The detection of CTO at CCTA, which occurs in 6.2% of CAD patients undergoing this non-invasive imaging exam, is associated with a 2-year mortality similar to moderate-to-severe CAD ( 51 ). The success rate of CTO-PCI was until recent times about 75–80% ( 48 ); nowadays, the marked technological advances in terms of devices, techniques and operator experience have increased the procedural success over 90% but obviously there remains a gap between non-CTO and CTO procedures. Unsuccessful attempts of revascularization are associated with worse outcome (30-day MACE: 14.8 vs. 5.5%), mainly due to a significantly higher rate of MACE in the immediate period following the procedure ( 52 ).…”

“…It allows visualization and evaluation of the entire coronary tree including the CTO lesion, which appears as a “missing segment” when using dual injection at invasive coronary angiography. This is particularly useful in long and tortuous CTOs and in ostial occlusions, in which the definition of the course and the features of the occluded segment are key information for PCI success ( 48 ). A precise mapping of lesion tortuosity and distal vessel anatomy may be assessed using 2- and 3-dimensional reconstructions from any arbitrary angle, allowing an accurate measurement of the length, cross-sectional area and diameter of the CTO.…”

Use of Intravascular Imaging During Chronic Total Occlusion Percutaneous Coronary Intervention: Insights From a Contemporary Multicenter Registry

“…11,12 Moreover, intravascular imaging can facilitate sizing of balloons and stents and optimize stent expansion and stent strut apposition. 13 We examined a large multicenter contemporary CTO PCI registry to determine the frequency of intravascular imaging use during CTO PCI and the associated procedural outcomes.…”