Coronary artery aneurysm after sequential stenting with bioresorbable vascular scaffolds
We report the case of a previously healthy 49-year-old woman who was referred to our cath lab for ACS NSTEMI and underwent a percutaneous coronary intervention (PCI) with a bioabsorbable vascular scaffold (BVS) on the right coronary artery (RCA) (Fig. 1a–c). Subsequent fractional flow reserve on the right posterolateral artery (RPL) showed the absence of persistent ischemia. Angiographic and optimal coherence tomography (OCT) evaluation performed 9 months later for stable angina (CCS III) indicated that a significant stenosis of the RPL ostium treated with a new BVS implantation on the RPL accidentally turned out in a ‘staged’ culotte stenting technique over the bifurcation RPL/right descending posterior artery (Fig. 1d). OCT final evaluation confirmed good apposition and expansion of the overlapped scaffolds and the mid-RCA was treated successfully with two BVSs. Final angiography showed no residual stenosis of both the lesions treated (Fig. 1e). Unfortunately, 25 months after the index procedure and 16 months after re-PCI, the patient was readmitted to our hospital for unstable angina. Angiographic and OCT control showed an intramedial dissection on the mid-RCA and a significant in-scaffold restenosis of the distal RCA, followed by a newly acquired aneurysm in the stented segment (Fig. 2a and b). Our decision-making process was dependent on two important issues: if and how to treat the patient? On the basis of the published literature, data on the prognostic impact of different types of aneurysms and relative treatments are scarce 1. Interventional modalities such as stent grafts or coils have been proposed. Conversely, complete resolution of cerebral amyloid angiopathy (CAA) without treatment has been described, but has to be counterbalanced carefully by the risk of rupture. Therefore, the optimal strategy should be tailored on the basis of symptoms, aneurysm size, pathophysiology, and expansion history.
Optimal intervention in our case was even further challenged by the coexistence of aneurysm and restenosis in the same segment and by the presence of multiple layers of BVS struts. Our strategy involved drug-eluting stent implantation on the distal RCA to address the issue of BVS restenosis. Because of positive FFR on the RPL, another drug-eluting stent was eventually implanted on the RPL. Postprocedural OCT showed resolution of restenosis on both the distal RCA and RPL with optimal strut apposition (Fig. 2c and d). Because of angiographic features and timing, CAA in our case was likely to belong to a chronic arterial response scenario, incidentally detected during angiography for recurrent symptoms caused by in-scaffold restenosis. Hence, a conservative approach was chosen.
Our revascularization strategy was continued with a conservative treatment of the mid-RCA. Seven months later, the patient underwent an exercise stress test, with no ECG or clinical evidence of ischemia. This case confirms CAA as a rare but possible complication after BVS implantation in bifurcation lesions. An amplified inflammation process of multiple layers of scaffolds during the bioresorption phase could play a major role in CAA formation and should be evaluated carefully when BVS bifurcation stenting is planned 2.
Moreover, this report raises new questions on the pathophysiology and treatment of CAA as PCI complications, even more unclear in the BVS setting. Hence, given the rarity of overall events and published data, the pathophysiological mechanisms need to be further elucidated and the optimal treatment should be based on a case-by-case approach.