Optical Coherence Tomography-Guided Bioresorbable Vascular Scaffold Implantation With Orbital Atherectomy for Calcified Chronic Total Occlusion

Case report 

A 67-year-old male with a past history of hypertension, diabetes, and dyslipidemia complained of neck and jaw pain after walking. Stress myocardial perfusion imaging showed ischemia in the left anterior descending artery (LAD) area. Coronary angiography at an outside hospital revealed a severely calcified chronic total occlusion of the proximal LAD with collateral flow from the right coronary artery. He was referred for revascularization of the LAD. 

Bilateral femoral access was obtained to perform simultaneous angiography of the left and right coronary artery systems (Figure 1). A 6 French VL3.5 guide was engaged in the left coronary artery. 

An Asahi Fielder wire (Abbott Vascular) with the support of a Finecross microcatheter (Terumo) was able to pass through the lesion. The microcatheter passed through the lesion and the Fielder wire was exchanged for a ViperWire (Cardiovascular Systems, Inc. [CSI]). Orbital atherectomy was performed at a rotational speed of 80,000 rpm in the proximal and mid LAD, using the 1.25 mm classic crown Diamondback 360 Coronary Orbital Atherectomy System (CSI). The lesion was predilated with a 3.0 mm noncompliant balloon at 16 atmospheres (atm). 

Optical coherence tomography (OCT) assessment after plaque modification demonstrated three-quadrant fibrocalcific plaques associated with the presence of calcium cracks in the proximal LAD (Figure 2). The proximal and distal reference mean diameters were 3.1 mm and 2.5 mm, respectively. The proximal and distal reference lumen areas were 7.60 mm2 and 4.92 mm2, respectively, and the lesion length was approximately 53.8 mm. 

A 3.5 x 28 mm Absorb GT1 bioresorbable vascular scaffold (BVS) (Abbott Vascular) was implanted at 16 atm in the proximal LAD. A 3.0 x 28 mm Absorb GT1 BVS was subsequently implanted at 16 atm in the mid LAD to cover the entire diseased segment, followed by post-dilation with a 3.5 mm noncompliant balloon at 20 atm. 

OCT assessment after post-dilation demonstrated good BVS expansion and apposition with no evidence of edge dissection (Figure 3). Eccentricity index (minimum scaffold diameter/maximum scaffold diameter in a frame) was 0.71 at the site of minimum lumen area and the average of all eccentricity indices of each frame within a scaffolded segment was 0.89.¹ Symmetry index [(maximum scaffold diameter – minimum scaffold diameter)/maximum scaffold diameter within a scaffolded segment] was 0.25.¹ At the site of overlap, which was approximately 1.6 mm long, the scaffolds were well expanded and apposed to the vessel wall. 

Discussion 

A severely calcified chronic total occlusion of the LAD was successfully treated with OCT-guided percutaneous coronary intervention using orbital atherectomy. A previous study demonstrated that moderate or severe target lesion calcification was detected by angiography in 38% of lesions and intravascular ultrasound analysis showed that the prevalence of target lesion calcification exceeded 70%.² Plaque modification with rotational or orbital atherectomy facilitates PCI for complex lesions with severe calcification.³ Intravascular imaging is useful in identifying characteristics of plaque morphology and OCT can detect calcification with a high accuracy.⁴ Furthermore, OCT is used to guide the revascularization procedures with BVS and assess appropriate deployment of BVS.¹ In our case, OCT assessment combined with angiography provided high-quality images, optimizing results of a PCI using BVS for calcified lesions.

References 

1. Garcia-Garcia HM, Serruys PW, Campos CM, et al. Assessing bioresorbable coronary devices: methods and parameters. J Am Coll Cardiol Img. 2014; 7: 1130-1148. 
2. Mintz GS, Popma JJ, Pichard AD, et al. Patterns of calcification in coronary artery disease. A statistical analysis of intravascular ultrasound and coronary angiography in 1155 lesions. Circulation. 1995; 91: 1959-1965. 
3. Tomey MI, Kini AS, Sharma SK. Current status of rotational atherectomy. J Am Coll Cardiol Intv. 2014; 7: 345-353. 
4. Tearney GJ, Regar E, Akasaka T, et al. International Working Group for Intravascular Optical Coherence Tomography (IWG-IVOCT). Consensus standards for acquisition, measurement, and reporting of intravascular optical coherence tomography studies: a report from the International Working Group for Intravascular Optical Coherence Tomography Standardization and Validation. J Am Coll Cardiol. 2012; 59: 1058-1072. 

This case is published with support from St. Jude Medical.