Huge Aneurysm Formation with Stent Dislocation

Huge Aneurysm Formation with Stent Dislocation after Implantation of Two TAXUS Stents

A 64-year-old male with no history of hypertension and diabetes mellitus presented with unstable angina. His coronary angiogram (CAG) revealed chronic total occlusion in middle left anterior descending artery (LAD) and he underwent implantation of two 3.0X28 mm TAXUS stents for proximal and middle LAD, respectively. He did not complain of any chest pain or dyspnea till follow-up CAG which was performed fifteen months after first intervention. Follow-up CAG showed aneurismal dilatation in proximal and middle TAXUS stent sites. Intravascular ultrasound showed huge aneurysm formation and separation of vessel wall from TAXUS stents in both proximal and middle LAD at their respective largest aneurysm sites (double-headed arrow), and about 3 mm-length gap between two stents (Figure 1A). Cardiac computed tomography angiography (CTA) showed aneurismal dilatation in proximal and middle LAD stents with dislocation of two stents (Figure 1B). Stent dislocation might be caused by geographical change by aneurismal dilatation. Because this patient did not complain of any chest symptoms, we finished the procedure without any intervention.

Coronary aneurysm after stent implantation is a rare complication and has been reported after drug-eluting stent implantation. Drug-eluting stents can cause substantial impairment in arterial healing characterized by lack of complete reendothelialization and persistence of fibrin when compared to bare-metal stent and can potentially lead to complications such as stent thrombosis and aneurysm formation. Inflammatory response limited to the arterial wall surrounding the stent that they interpret as a hypersensitivity reaction to the polymer leading to incomplete endothelialization and tissue damage. Inhibition of the healing process by paclitaxel could have contributed to the expansion of the weakened segments of arterial wall secondary to the trauma by stenting resulting in aneurysm formation. Problems due to the polymer or drug effect after drug-eluting stent implantation may be more frequent than what is reported in the literature.

Fig. 1. (A) Coronary angiography showed aneurismal dilatation in proximal and middle TAXUS stent sites and intravascular ultrasound showed huge aneurysm in both proximal (with stent area of 6.4 mm² and maximum external elastic membrane area of 48 mm²) and middle left anterior descending artery (LAD) (with stent area of 5.8 mm² and maximum external elastic membrane area of 40 mm²) at their respective largest aneurysm sites (double-headed arrow), and about 3 mm-length gap between two stents. (B) Cardiac computed tomography showed aneurismal dilatation in proximal and middle LAD stents with dislocation of middle LAD stent from proximal LAD stent.

References

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