Pseudoaneurysm diagnosis and management

Introduction

Cardiac pseudoaneurysms are an uncommon occurrence; however, they are associated with significant risk of complications. ^, A pseudoaneurysm is a contained rupture of the arterial vessel or myocardial wall. A single layer of pericardium or adhesions lines the sac, increasing the risk of rupture and cardiac mortality approaching 30% to 50%. This is in comparison to a true aneurysm, which is thinning of the wall and contains all three layers of the endocardium, myocardium, and epicardium. ^,

Previously, surgical management of pseudoaneurysms was considered the gold standard; however, it is associated with significant mortality approaching 23%. ^, Recent growth of structural heart procedures has helped in identifying percutaneous solutions for the management of pseudoaneurysms in patients who otherwise have high surgical risk. This chapter will discuss the various techniques and approaches for the diagnosis and management of pseudoaneurysms.

Incidence, presentation, and natural history

There are no prospective studies evaluating the natural history of pseudoaneurysms because of the low incidence. Retrospective studies have suggested that many patients are asymptomatic, with diagnosis made as an incidental finding on imaging. Other presentations include heart failure, chest pain, syncope, arrhythmias, or thromboembolism ( Table 29.1 ). Recently, cases related to wire perforations/injury during structural heart procedures such as transcatheter aortic valve replacement (TAVR) and mitral valve replacements have also been reported.

The left ventricle (LV) is the most common location of pseudoaneurysms. The etiology of LV pseudoaneurysms is variable according to the location. Myocardial infarction (MI) is the most common etiology, usually leading to an inferior-posterolateral scar and subsequent pseudoaneurysm formation. Cardiovascular surgery is the second most common cause. Right ventricular pseudoaneurysm is frequently seen with congenital surgeries, and paravalvular pseudoaneurysm, including mitral-aortic intervalvular fibrosa, can result as a complication from valve surgery or endocarditis.

Other causes of LV pseudoaneurysms include trauma to the chest, endocardial electrophysiologic procedures, and structural heart procedures such as TAVR.

Aortic pseudoaneurysms may occur after aortic repairs, trauma, or endarteritis. Coronary artery pseudoaneurysms can be related to prior percutaneous coronary intervention (PCI), vasculitis, or spontaneous dissection.

Diagnosis

In the contemporary era, multimodality imaging is the key for diagnosis and procedural planning in pseudoaneurysms. Biplane left ventriculography was the test of choice for surgical planning in the past and still has an important role in the assessment of the defect during percutaneous closure. Transthoracic echocardiogram (TTE) is usually the initial test in most patients. Transesophageal echocardiogram, especially 3D modality, may be helpful in some cases to assess the size, depth, and surrounding cardiac structures. Computed tomography (CT) scan with full 3D reconstruction or cardiac magnetic resonance (CMR) imaging is almost always performed to carefully plan any intervention by studying the following ( Figs. 29.1 to 29.3 ):

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  Precise pseudoaneurysm location to determine the best access approach (e.g., retroaortic, transseptal, transapical)

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  Size and extent of pseudoaneurysm and its neck to determine closure device size and type

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  Risk of interaction of occluder device with surrounding structures (e.g., risk of valve impingement and risk of coronary occlusion or compression)

The field of 3D printing further enhanced preprocedural planning and management of pseudoaneurysms. Patient-specific 3D printed cardiac models with cardiac tissue characteristics have allowed for bench testing to simulate closure procedures and reduce the rate of trial and error ( Fig. 29.4 ).

Guidelines and patient selection

There are no specific guidelines for the treatment of pseudoaneurysms. Fig. 29.5 outlines our approach to management.

The indications for treatment may include:

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  Symptoms

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  Acute complications of MI

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  Acute complication of a structural/electrophysiologic procedure

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  High risk of rupture (Laplace law: Wall stress = Pressure * radius / 2)

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  Presence of thrombus and risk of thromboembolism.

Conservative management

Minimal data are available on conservative management of pseudoaneurysms. In a systematic review of 31 patients who were managed conservatively, 48% died at a median of 1 week, with the remainder of patients alive at a median of 156 weeks. This suggests that if the patient survives the early period after pseudoaneurysm formation and their risk of surgical or percutaneous treatment is considered prohibitive, conservative management may be appropriate. However, this should be pursued with caution, and very close follow-up with serial imaging is important. We previously published a case of conservatively managed LV pseudoaneurysm after endocardial ablation in a congenital heart disease patient with a single ventricle. The patient was considered at prohibitive risk for repeat surgery and percutaneous closure carried a high risk of interfering with the single mechanical valve. The patient was followed serially with CT scans for 3 months (available follow-up until 1 year) without any change in the size of pseudoaneurysm. She was already on anticoagulation for the mechanical valve.

In patients who are managed conservatively, anticoagulation is recommended to reduce the risk of thrombus formation and systemic embolism.