Covered Stent Implantation for the Treatment of an Aneurysm Involving a Coronary Bifurcation

Coronary artery aneurysms (CAAs) are occasionally reported among patients undergoing coronary angiography, with an incidence varying from 0.3% to approximate 5%.^1,2 More than half of CAAs are due to coronary atherosclerosis, but occasionally they are related to other pathological entities.³ In the majority of cases, they accompany atherosclerotic coronary disease.^4,5
Most of the patients with CAA are asymptomatic, but when symptoms occur, angina is the most commonly reported.² For patients with symptoms or signs of significant ischemia despite medical therapy, percutaneous or surgical coronary vascularization can restore myocardial perfusion.6 CAAs have been percutaneously excluded with coil embolization, saphenous vein-covered stents and polytetrafluoroethylene (PTFE)-covered grafts.^7,8
However, the interventional treatment of CAAs may represent a challenge, in particular when coronary bifurcations are involved.

Case Report. A 56-year old male patient was admitted to our center with stable angina and a positive stress test with ST-segment depression in anterior leads. The risk factors included hypertension, hypercholesterolemia and smoking. Previous PCI with bare-metal stent (BMS) implantation in the first obtuse marginal branch (first OM) was performed 2 years earlier.
The coronary angiogram revealed an aneurysm of the mid-segment of the left anterior descending artery (LAD) involving the bifurcation with the first diagonal (first DG) artery (Figure 1). There was significant stenosis on the LAD proximal to the aneurysm. The first DG branch originated at the proximal margin of the aneurysm and had moderate ostial narrowing. The lateral branch of the first DG artery was occluded. The first OM was patent, without in-stent restenosis. Collateral circulation was present to the distal segment of the right coronary artery (RCA) and to the lateral branch of the first DG. The mid-segment of the RCA was occluded. The left ventricle had normal contractility.The patient was informed regarding the therapeutic options, and he opted for percutaneous treatment.
Antiplatelet therapy with a loading dose of 600 mg of clopidogrel was initiated, and 10,000 units of heparin were administered intravenously. The RCA was recanalized using a 0.014 inch intermediate PT Graphics guidewire (Boston Scientific Corp., Natick, Massachusetts). Two BMS were implanted in the mid-segment of the vessel (Driver 3.0 x 15 mm and Micro Driver 2.5 x 14 mm; Medtronic, Inc., Galway, Ireland) with an optimal angiographic result (Figure 2).
A moderate-support Marker guidewire (Boston Scientific) was then positioned in the LAD across the aneurysm. The Marker Wire features two 5 mm markers, with 15 mm between markers to be used for precise length assessment. The measured aneurysm length was 12 mm (Figures 3A and B). A second 0.014 inch intermediate PT Graphix guidewire (Boston Scientific) was placed in the first DG and was used for recanalization of the lateral branch of the first DG. Predilatation of the LAD bifurcation lesion was performed using a 3.0 x 11 mm JoCath Maestro balloon (JoMed/Abbott Vascular, Rangendingen, Germany). Due to the involvement of the LAD-first DG bifurcation, a V-fashioned bifurcation system was used which consisted of a 3.0 x 16 mm JoStent coronary stent graft (JoMed/Abbott Vascular) placed in the LAD across the CAA and a 2.5 x 14 mm Micro Driver BMS (Medtronic) in the first DG branch. The proximal markers of the balloons were positioned in the LAD, proximal to the bifurcation. Both stents were simultaneously deployed at 14 atm followed by sequential high-pressure inflation of the 2 stent balloons. The procedure was concluded with simultaneous balloon inflations at 18 atm (Figure 3). The control angiogram showed an optimal result with complete exclusion of the aneurysm and patent first DG branch (Figure 4).
The patient was discharged the next day on clopidogrel (75 mg/day) for 9 months and aspirin (100 mg/day) indefinitely. He underwent an uneventful 1-year follow up at which time the stress test was negative. The follow-up angiogram revealed a patent LAD-first DG bifurcation, and no restenosis was present in the segments treated with the V-configured stent system (Figure 5). The lateral branch of the first DG had moderate restenosis and the RCA was patent.

Discussion. Coronary artery aneurysms (defined as discrete or diffuse coronary dilatation that exceed the diameter of normal adjacent segments or the diameter of the patient’s largest coronary vessel by 50%) have been reported to be sealed percutaneously with various techniques and devices: coil embolization, autologous saphenous vein-covered stent grafts and PTFE-covered stents.^7,8,9 Multiple or very large coronary aneurysms are usually treated with coronary artery bypass surgery.^6,9 The usual technique of aneurysm exclusion with a covered stent is to deploy the device across the entire length of the aneurysmal segment. Sometimes the interventional treatment of an aneurysm involving the origin of a significant side branch may become technically demanding.
In our case, the aneurysm involved the LAD/first DG bifurcation and the side branch originated at the proximal margin of the aneurysmal segment. Due to the nonavailability of a dedicated bifurcation system with PTFE-covered stents, we simultaneously implanted a PTFE-covered stent across the aneurysm and a BMS in the side branch, with an optimal angiographic outcome. The patient remained symptom-free at 1-year follow up. To our knowledge, this result represents the first report of the use of a V-configured system with a covered stent and a BMS for the exclusion of a CAA involving a bifurcation.
Depending on the position of the origin of the side branch — i.e., arising from the proximal part, the middle or from the distal margin of the aneurysm — a different approach may be applied. In a case report of a large coronary aneurysm involving bifurcation with a side branch originating from the distal part of the aneurysm, the authors used a custom-made T-fashioned bifurcation system with both covered and BMS.¹⁰
In conclusion, we describe the technique of percutaneous sealing of a CAA involving a bifurcation achieved with a covered stent and a BMS as a V-configured system in a patient with three-vessel disease.

References

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