Management of Concurrent Left Ventricular Pseudoaneurysm and Mitral Annular Calcification: A Case Report

Abstract

We describe the treatment of a 54-year-old man with a history of methicillin-resistant Staphylococcus aureus pericarditis who presented with left ventricular pseudoaneurysm following prior left anterior thoracotomy pericardial window. Surgical intervention included pseudoaneurysm repair using a wide patch. Additionally, an attempted mitral valve repair was converted to replacement due to intraoperative findings of significant calcification of the mitral anterior leaflet and annulus, along with suspected rheumatic changes. Our report highlights the management of concurrent cardiac pseudoaneurysm and mitral annular calcification, emphasizing the role of comprehensive imaging both perioperatively and intraoperatively in achieving durable outcomes.

Case report

Cardiac pseudoaneurysm is a rare but potentially life- threatening condition that can arise when an injury to the heart results in the thinning of cardiac tissue. Unlike true aneurysms, pseudoaneurysms form due to a breach in this tissue, with blood contained by surrounding tissues rather than by intact cardiac walls. Pseudoaneurysms carry a risk of rupture as high as 45% and mortality rates that can approach 50%, making timely diagnosis and intervention crucial [1,2].

We present a unique case of left ventricular pseudoaneurysm that required patch repair at the level of the atrioventricular groove, as well as mitral valve replacement due to calcification of the anterior leaflet and mitral annulus. This retrospective case study was conducted in accordance with ethical standards and was reviewed and approved by the Institutional Review Board of the University of Maryland (IRB approval no., HP-00076929). The requirement for informed consent from the patient was omitted because of the retrospective design of this study.

A 54-year-old man with a history of type 2 diabetes mellitus and atrial fibrillation presented to the hospital with new-onset left-sided chest pain, dyspnea on exertion, and bilateral leg swelling. One year prior, he experienced an episode of methicillin-resistant Staphylococcus aureus (MRSA) pericarditis with infected pericardial effusion. This was treated via left anterior thoracotomy to create a pericardial window, along with the placement of an open pericardial drain. At that time, the patient exhibited no evidence of myocardial abscess or infective endocarditis; he was afebrile, transthoracic echocardiography (TTE) revealed no vegetations, and no systemic or peripheral signs of endocarditis were noted. Imaging indicated only pericardial effusion without outpouching lesions, and postoperative computed tomography showed residual bilateral pleural effusions but no other abnormalities.

The pericardial window procedure involved a 6×4 cm resection of the anterolateral pericardium, accompanied by the drainage of a 1.6×8.0 cm fluid collection situated along the base of the left ventricle. The infection was presumed to be secondary to diabetic foot ulcers or osteomyelitis, although evaluations to identify primary infectious foci yielded negative results. The patient underwent a 12-day course of intravenous antibiotics followed by 6 weeks of oral daptomycin.

During this presentation, computed tomography angiography (CTA) revealed a middle mediastinal mass measuring 6.5×8.7×6.7 cm posterior to the left atrium. Magnetic resonance imaging (MRI) confirmed the presence of a large pseudoaneurysm originating from the inferolateral mitral valve annulus, with active flow from a left ventricular fistula (Fig. 1). The location of the pseudoaneurysm corresponded to the site of the previous pericardial drain. TTE demonstrated minimal mitral valvular calcification, a mean gradient of 5 mm Hg, trace mitral regurgitation, and an ejection fraction of 55%. Given the patient’s symptoms and the risk of pseudoaneurysm rupture, surgical intervention was deemed necessary.

Fig. 1.

Cardiac magnetic resonance imaging. (A) Sagittal view highlighting the dimensions of the pseudoaneurysm. (B) Additional sagittal view showing the location of the pseudoaneurysm. (C) Sagittal view of the pseudoaneurysm with a small defect indicated in yellow. (D) Horizontal view displaying the posterior position of the pseudoaneurysm relative to the left ventricle and left atrium (yellow arrow).

The procedures performed included lysis of adhesions from the previous pericardial window, patch repair of the left ventricular pseudoaneurysm, and mitral valve replacement. Cardiopulmonary bypass (CPB) was initiated using standard central bicaval cannulation. The left atrium was exposed via a transseptal approach through the fossa ovalis, which allowed access to the mitral valve without disturbing the pseudoaneurysm.

Upon exposure of the mitral valve apparatus, both anterior and posterior leaflets initially appeared to have adequate mobility and seemed amenable to repair. The posterior leaflet was incised at the annulus and reflected anteriorly to expose the atrioventricular groove. Two distinct sinuses were observed on the ventricular side of the posterior mitral valve annulus, leading into the pseudoaneurysm space (Fig. 2). The annulus and pseudoaneurysm were irrigated with antibiotic solution. A patch was appropriately sized and attached to the left ventricle, starting from the base of the posterior papillary muscles, covering the posterior annulus, and extending 2 cm onto the atrium.

Fig. 2.

Intraoperative view of the sinuses leading into the pseudoaneurysm, situated just below the posterior mitral valve leaflet. (A) The annular defect as seen from the surgeon’s perspective. The solid yellow arrow indicates the opening of the defect. The dotted yellow line delineates the entire length of the opening, including the 2 sinuses. (B) The annular defect as viewed through one of the sinuses from the surgeon’s perspective, with a probe inserted to measure depth (yellow arrow).

Mitral valve repair was attempted by reattaching the posterior leaflet to the patch and placing an annuloplasty band. After separation from CPB, no mitral regurgitation was observed; however, the mean gradient across the mitral valve was 12 mm Hg, raising concerns about anterior leaflet mobility. The repair was deemed unlikely to be durable in the long term, leading to the decision to proceed with mitral valve replacement. Upon resection of the anterior leaflet, significant calcium deposits were discovered on the underside of the A1 and A3 scallops, which likely contributed to the restricted motion of the anterior leaflet. The calcium along the anterior annulus was debrided, and the mitral valve was replaced using ventricular pledgeted 2-0 Ethibond sutures placed circumferentially around the annulus. A 29-mm Mitris valve (Edwards Lifesciences) was implanted. Post-replacement intraoperative transesophageal echocardiography revealed no mitral regurgitation and an improved mean gradient of 2 mm Hg, without evidence of paravalvular leak.

Postoperative TTE indicated a residual posterior echo-free space measuring 4.5 cm, which was slowly receding along the basal to mid-inferior wall at the site of the previously identified pseudoaneurysm; no ventricular communication was noted. The patient was discharged home on the eighth postoperative day.

Discussion

Pseudoaneurysms most commonly arise as a complication of myocardial infarction, particularly when reperfusion is delayed, and occurs in less than 1% of such cases. Other causes include previous cardiac surgery, chest trauma, infective endocarditis, and percutaneous cardiac intervention [3]. Common symptoms include chest pain, dyspnea, and signs of heart failure. Diagnosis typically involves multiple imaging modalities, such as echocardiography, cardiac MRI, and CTA, while treatment generally necessitates open surgical repair.

Left ventricular pseudoaneurysm with a potential infectious etiology is extremely rare, with only 23 cases reported in the literature as of 2020 [4]. Managing concurrent left ventricular pseudoaneurysm and mitral annular calcification (MAC) presents meaningful challenges due to the complex nature of both conditions. The patient’s history of MRSA pericarditis, accompanied by an infected pericardial effusion that necessitated pericardial window creation and drain placement, further complicates the situation, as this may represent an infected space. The development of the pseudoaneurysm at the site of the previous pericardial intervention highlights a rare and serious complication associated with such procedures.

While MRSA is not the most common causative agent for this condition, its involvement can lead to more severe disease presentations than that of other microorganisms. MRSA pericarditis often presents with purulent effusion and can rapidly progress to complications such as cardiac tamponade. The aggressive nature of MRSA infections, combined with treatment challenges due to antibiotic resistance, contributes to the increased virulence observed in cases of MRSA pericarditis. Specifically, MRSA toxin production can cause substantial tissue damage and necrosis in certain contexts [5]. The combination of surgery, which creates a potential space, and infection, which can weaken the structural integrity of the tissue, may have led to the formation of this pseudoaneurysm.

Comprehensive imaging played a key role in diagnosis and the planning of the surgical approach. The use of CTA, MRI, and TTE provided detailed insights into the anatomical relationships and functional impacts of the pseudoaneurysm and MAC. Surgical planning required identification of the precise location of the pseudoaneurysm and its relationship to the prior pericardial drain placement, as this information helped guide decisions regarding cannulation and the choice of surgical approach.

When managing a pseudoaneurysm surgically, there is always a risk of rupture prior to cannulation and adequate exposure. Thorough preoperative imaging is essential for evaluating the pseudoaneurysm’s characteristics and the rupture risk, as well as for determining its underlying cause. This information is vital for making informed decisions regarding the most appropriate surgical approach. In the present case, the pseudoaneurysm was well demarcated with no signs of impending rupture or pericardial effusion, indicating that standard cannulation principles would be safe to apply. Nevertheless, given the intrinsic risks associated with any pseudoaneurysm, we opted to establish peripheral micropuncture access as a precaution.

To best visualize the posterior annulus and posterior left ventricle, we determined that a transseptal approach would provide optimal exposure. It is crucial to sharply mobilize the posterior leaflet from the annulus at the annular level to preserve as much tissue as possible. In the context of left ventricular pseudoaneurysm, surgeons can choose between direct closure and a patch placement technique. However, the location of the pseudoaneurysm and the quality of the surrounding tissue must be considered. For this case, due to the posterior positioning of the pseudoaneurysm, we opted to use a bovine pericardium patch. We recommend slightly oversizing the patch to alleviate tension on the suture line [6]. This line was created using multiple running Prolene sutures. The patch was designed to extend well into the left ventricle, cover the entire posterior annulus, and attach to the left atrial tissue 2 cm to the atrial side of the annulus. Repair and replacement sutures were placed in the patch at the level of the native annulus, which was indicated with a purple marker. Considering the patient’s young age, we believed that attempting repair was reasonable (Fig. 3). When attempting to spare the anterior leaflet, calcium on the underside of this leaflet at the annulus is nearly impossible to visualize, necessitating optimal transesophageal echocardiographic imaging. Had this been noticed preoperatively, we would have opted for a replacement initially.

Fig. 3.

(A) Intraoperative view of the pericardial patch overlaying the pseudoaneurysm defect (yellow arrow). (B) Annuloplasty ring positioned over the pericardial patch (yellow arrow).

This case highlights the successful management of a rare presentation that included left ventricular pseudoaneurysm along with significant calcification of the anterior leaflet and annulus. We describe dynamic intraoperative decision-making supported by detailed imaging, underscoring the importance of a multidisciplinary and flexible strategy to address such challenging cases. This report contributes valuable insights into the management of complex cardiac pathologies, emphasizing the need for careful planning and precise execution to achieve favorable patient outcomes.

Funding Statement

Funding This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.