Aortic protrusion of left main coronary artery stent during percutaneous coronary intervention after redo mitral valve replacement: surgical removal and new stent implantation

Abstract

An 83-year-old male patient presented to our hospital with complaints of chest pain, shortness of breath, and leg swelling. His medical history included a biological mitral valve replacement (MVR) for mitral stenosis 9 years ago and percutaneous coronary intervention (PCI) to the circumflex (CX) and diagonal arteries 5 years ago. Echocardiography and coronary angiography (CAG) revealed moderate mitral valve stenosis, left atrial thrombus, and critical stenosis in the left main coronary artery (LMCA) and CX artery. Redo MVR, coronary artery bypass grafting (CABG), tricuspid valve repair, and thrombus excision were planned. However, CABG could not be performed due to extensive pericardial adhesions. After redo MVR, during LMCA stenting, the proximal portion of the stent protruded towards the aorta and hemodynamic instability developed. The protruded stent was surgically removed, and a drug-eluting stent (DES) was successfully implanted into the LMCA.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-025-01957-0.

Introduction

Coronary artery bypass grafting (CABG) has long been considered the standard treatment for patients with left main coronary artery (LMCA) stenosis. However, in recent years, percutaneous coronary intervention (PCI) has emerged as a viable alternative for this patient population. Nevertheless, the technical challenges and potential complications associated with PCI should be carefully considered.

Case report

An 83-year-old male patient presented to our cardiology outpatient clinic with complaints of chest pain, dyspnea, and leg swelling. His medical history revealed that he had undergone bioprosthetic mitral valve replacement (MVR) for mitral valve stenosis 9 years ago and PCI for lesions in the circumflex (CX) and diagonal arteries 5 years prior. The patient was admitted to the hospital for further evaluation and treatment, including transthoracic echocardiography (TTE) and coronary angiography (CAG). TTE revealed a mean pressure gradient of 12 mmHg across the bioprosthetic mitral valve, with a valve area of 1.36 cm², consistent with moderate mitral stenosis. Assessment of the tricuspid valve showed an annular diameter of 50 mm and moderate tricuspid regurgitation. Additionally, a widespread thrombus was observed in the left atrium. CAG demonstrated significant stenosis in the LMCA and CX coronary arteries (Fig. 1A). Based on these findings, redo MVR, CABG, tricuspid valve repair, and left atrial thrombus excision were planned for the patient.

Fig. 1.

A Coronary angiographic image of the stenotic left main coronary artery. B Coronary angiographic image showing the left main coronary artery stent protruding into the aorta

Surgical procedure

A median sternotomy was performed. Venous cannulation was achieved via the right jugular vein and femoral vein, while arterial cannulation was performed through the right femoral artery. A vent cannula was placed in the right superior pulmonary vein. Antegrade Del Nido cardioplegia solution was administered, achieving cardiac arrest. Cardiopulmonary bypass (CPB) was initiated. Cross-clamp was applied to the ascending aorta. Pericardial adhesions involving the right atrium and right ventricle were meticulously dissected. However, due to severe pericardial adhesions on the left side and posterior region of the heart, dissection of these areas was not feasible, and access to the left anterior descending artery and CX coronary artery territories could not be achieved. Consequently, it was decided to proceed with elective PCI in the angiography laboratory postoperatively, and the surgery was continued. Using a trans-septal approach via a right atriotomy, the organized thrombus in the left atrium was excised, extensively irrigated with saline, and aspirated. The degenerated biological mitral valve was excised and replaced with a bioprosthetic MVR (St. Jude Epic, size 29, USA). The tricuspid valve was tested with saline, revealing a central leak. The tricuspid valve was repaired using the De Vega annuloplasty technique and subsequently tested with a saline solution. The absence of tricuspid valve regurgitation was confirmed. The patient was weaned off CPB uneventfully, and the procedure was successfully completed (Video 1). Eight hours postoperatively, the patient developed hemodynamic instability characterized by hypotension unresponsive to volume resuscitation and inotropic support. ST segment elevation was observed in the anterior leads on the electrocardiogram. Repeat TTE demonstrated hypokinetic areas in the left ventricle without evidence of tamponade. The patient was promptly taken to the catheterization laboratory for further evaluation.

PCI was planned for the LMCA and CX arteries. The critical lesion in the CX artery was located proximal to the CX stent. Near-complete patency of the critical lesion in the CX artery was achieved with the implantation of a 4.0 × 18 mm drug-eluting stent (DES) (Resolute Onyx, Medtronic). The procedure for the LMCA was initiated with predilation using a 3.75 × 15 mm balloon. Subsequently, a 4 mm × 12 mm DES (Resolute Onyx, Medtronic) was implanted. Postdilation was performed with a 5.0 × 10 mm balloon to ensure optimal fixation. However, the LMCA stent was observed to protrude into the aorta (Fig. 1B). Due to severe tortuosity and advanced atherosclerosis of the LMCA, DES protruded outward despite pre- and post-dilatation with a balloon. Multiple attempts were made to replace the protruding stent using PCI; however, they were unsuccessful (Video 2). Due to the patient’s hemodynamic instability, the procedure was terminated.

The patient was taken for emergency surgery again. After median sternotomy, venous cannulation was performed through the right atrium, arterial cannulation through the aorta, and a vent cannula was placed in the right superior pulmonary vein. Cross-clamp was applied to the ascending aorta, and antegrade Del Nido cardioplegia solution was administered. CPB was initiated. Aortotomy was performed, and the LMCA stent, which was protruding into the aorta, was carefully removed (Fig. 2A). Additional cardioplegia was delivered through the coronary ostia. A new 4 mm × 12 mm DES was then placed into the LMCA (Fig. 2B). Subsequently, the LMCA stent was fixed with postdilation using a 5.0 × 10 mm balloon. Since we did not have a hybrid operating room, the removal of the protruding LMCA stent and implantation of a new stent were performed using standard surgical techniques under direct visualization, guided by preoperative angiographic findings. The correct positioning and patency of the LMCA stent over the lesion were confirmed by administering cardioplegia through the LMCA ostium for testing (Video 3). Before discharge, control echocardiography and CAG were performed (Fig. 3 and Video 2). The functionality of the valve was confirmed, and it was observed that the stent did not protrude into the aorta.

Fig. 2.

A Intraoperative image of the left main coronary artery stent protruding into the aorta. B Intraoperative image of the surgical stent implantation in the left main coronary artery

Fig. 3.

Coronary angiographic image of the left main coronary artery after surgical stent implantation

Discussion

While PCI is a commonly preferred method for the treatment of LMCA lesions, it carries various technical challenges and risks of complications. Especially in cases of severely calcified lesions, tortuous vessels, attempts to re-stent through a previously placed stent, or during removal of a deformed stent, the technical success of PCI may be negatively affected. In such cases, factors that directly affect the success of the procedure include the stent’s design, strut thickness, metal platform, whether it is bare-metal or drug-eluting, advancements in stent delivery systems, and improvements in lesion preparation techniques. One of the complications that can occur during PCI is stent displacement and damage. This can lead to serious consequences, such as stent thrombosis, coronary artery embolization, bleeding requiring transfusion, acute myocardial infarction, and even the need for CABG or aortic valve surgery. Even more concerning, when the stent dislodges and exits the coronary artery, life-threatening complications, such as cerebral stroke and peripheral arterial occlusion, may occur, potentially leading to death. Various management techniques are available in the event of stent dislodgement. These include the small balloon technique, capturing and retracting the stent with a snare, leaving the stent in the coronary artery and crushing it with another stent, or parking the stent in a peripheral artery. However, the success of these techniques may vary depending on the urgency of the situation and the stent’s position [1]. Acute stent malapposition (ASM) occurs when the stent struts fail to make close contact with the intimal layer of the vessel wall after primary stent deployment. The incidence of acute stent malapposition in the LMCA following successful PCI has been reported as 26.2% per patient and per lesion. In LMCA lesions with ASM, the most common location was the proximal LMCA, accounting for 64.5% of cases. Larger stent diameter, greater stent area, and increased lumen area play a significant role in the development of ASM in LMCA stenting. ASM may lead to adverse clinical outcomes, including in-stent restenosis and stent thrombosis [2].

According to the 2021 American College of Cardiology/American Heart Association (ACC/AHA) guidelines, in patients with stable ischemic heart disease and significant LMCA stenosis, PCI is a reasonable option in cases with low-to-moderate anatomic complexity, provided that PCI can achieve equivalent revascularization to CABG. In such cases, PCI may improve patient survival. Recent meta-analyses have compared patients with critical LMCA stenosis who underwent PCI with DES to those who underwent CABG. The findings indicate that there is no statistically significant difference in the 5-year all-cause mortality rate between PCI and CABG. However, the PCI group has a higher risk of spontaneous myocardial infarction and repeat revascularization compared to the CABG group. There is no significant difference in the risk of stroke between PCI and CABG [3].

Furthermore, PCI can be considered for patients with LMCA stenosis who are poor candidates for surgery. Reasons for poor surgical candidacy include unfavorable distal targets for revascularization, severe left ventricular dysfunction, or the presence of significant lung disease. CABG remains the gold standard for patients with LMCA stenosis who have high anatomical complexity or significant multivessel coronary artery disease. Factors that increase the complexity of coronary anatomy include LMCA disease, trifurcation and complex bifurcation lesions, ostial LMCA disease, and severe calcification. Additionally, in diabetic patients with LMCA stenosis and multivessel coronary disease, when dual antiplatelet therapy is contraindicated or simultaneous cardiac surgery is required, CABG is preferred over PCI [4]. The surgical LMCA stent implantation technique can help prevent both aortic and LMCA dissections. Additionally, it helps prevent the stent from protruding again. Moreover, this approach provides an opportunity for immediate intervention, if any complications related to stent implantation occur.

In this case, the proximal part of the stent placed in the LMCA protruded into the aorta, leading to continued hemodynamic instability. This necessitated the patient’s urgent hybrid coronary revascularization.

Conclusion

In patients with a protruding stent in the LMCA who require CABG but cannot undergo the procedure, surgically removing the deformed stent and placing a new stent can be an effective treatment option. This approach can be successfully performed with the collaboration of cardiac surgery and interventional cardiology teams. If we had a hybrid operating room, we could have successfully performed the valve surgery and stent implantation in a single session. The experiences gained from this case can guide similar situations in the future.

Supplementary Information

Below is the link to the electronic supplementary material.

Abbreviations

MVR

Mitral valve replacement

PCI

Percutaneous coronary intervention

CX

Circumflex

LMCA

Left main coronary artery

CAG

Coronary angiography

CABG

Coronary artery bypass grafting

TTE

Transthoracic echocardiography

CPB

Cardiopulmonary bypass

DES

Drug-eluting stent

Author contribution

BNA: agreement to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. KN: Substantial contributions to the design of the work. YA: Drafting the work and revising it. DD: Final approval of the version to be published.

Funding

None.

Data availability

The data supporting the findings of this study are available upon reasonable request from the corresponding author.

Declarations

Ethics approval

Not applicable.

Informed consent statement

Written consent was obtained from the patient.

Statement of human and animal rights

Not applicable.

Conflict of interest

The authors declare that there are no competing interests.