Successful intravascular lithotripsy after all other options failed with stent under-expansion: a case report and review of alternative options.

Background: Stent under-expansion, often caused by severe circumferential coronary calcification, must be prevented as it increases the risk of neoatherosclerosis and stent thrombosis. Intravascular lithotripsy (IVL) is an effective lesion preparation strategy to enable sufficient expansion of a stent that was initially not sufficiently expanded. Case summary: A 62-year-old male patient presented in our emergency department due to unstable angina. Coronary angiography revealed one-vessel coronary artery disease with high-grade stenosis of the proximal to mid right coronary artery. Direct implantation of a drug-eluting stent was performed. However, stent under-expansion was noticed. Post-dilatation with semi-compliant balloon up to 24 bar was unsuccessful. Subsequent dilatation with an ultra-high-pressure OPN non-compliant balloon at 50 bar resulted to balloon rupture but stent under-expansion remained. Therefore, IVL was performed, resulting in complete stent expansion already at 4 bar. The patient was put on dual platelet treatment, and his further clinical course was uneventful after 6 months of follow-up. Discussion: The present case report highlights the role of IVL as a safe and effective treatment option in case of immediate stent under-expansion. This has significant implications on daily practice as under-expansion may lead to high rates of in-stent restenosis and stent thrombosis. Furthermore, this case report underlines the impact of lesion preparation, even in presumably less complex lesion by angiographic criteria.