Dual presentation of a giant left ventricular pseudoaneurysm and true aneurysm.
Article Type: Clinical report
Subject: Ventricular aneurysms (Development and progression)
Ventricular aneurysms (Diagnosis)
Ventricular aneurysms (Care and treatment)
Authors: Grant, Erica N.
Huang, Norman
Joshi, Girish P.
Aguirre, Marco A.
Pub Date: 01/01/2012
Publication: Name: Baylor University Medical Center Proceedings Publisher: The Baylor University Medical Center Audience: Academic Format: Magazine/Journal Subject: Health Copyright: COPYRIGHT 2012 The Baylor University Medical Center ISSN: 0899-8280
Issue: Date: Jan, 2012 Source Volume: 25 Source Issue: 1
Geographic: Geographic Scope: United States Geographic Code: 1USA United States
Accession Number: 278509853
Full Text: With medical advances, mortality and morbidity rates associated with myocardial infarction (MI) have declined dramatically (1). Nevertheless, cardiogenic shock is the most common cause of death after an acute MI, followed by left ventricular (LV) rupture (2). A pseudoaneurysm, albeit rare (3), is more likely to rupture than is a true aneurysm and thus is a post-MI complication that warrants urgent surgery (4). It is usually the result of an infarction involving the entire thickness of the myocardium. A localized pericarditis develops, and the resulting adhesions between the visceral and parietal pericardium rupture, with extravasated blood being contained by the adherent pericardium. The aneurysmal wall contains dense fibrous tissue but lacks myocardial fibers and coronary arteries. A true aneurysm, in contrast, consists of focal convex deformities of the heart, has wide communications between the aneurysmal cavity and left ventricle, contains myocardial fibers, and is lined by the former endothelium (3). This area of thin myocardium subsequently moves dyskinetically (5). Figure 1 illustrates the two differing pathologies (3).

[FIGURE 1 OMITTED]

Although transthoracic echocardiography (TTE) has been most studied in distinguishing pseudoaneurysms and true aneurysms (5), transesophageal echocardiography (TEE) is considered superior in the evaluation of pseudoaneurysms (6, 7). We report intraoperative management of a case presented for repair of a giant LV pseudoaneurysm and true aneurysm.

CASE REPORT

A 47-year-old woman with a body mass index of 35.3 kg/[m.sup.2] and hypertension, type 2 diabetes mellitus, dyslipidemia, hypothyroidism, and coronary artery disease presented with a 2-week history of lower-extremity/abdominal edema, shortness of breath, paroxysmal nocturnal dyspnea, a productive cough, and weakness/fatigue. Two months prior, she was admitted to an outside hospital following an acute MI. Cardiac catheterization at that time showed 100% left anterior descending artery and 90% posterior LV artery occlusion, diffuse circumflex disease, "faint" right to left collaterals from the right coronary artery to the left anterior descending artery, severely reduced LV function with anterior akinesis, and an anteroapical aneurysm. Additionally, her hospital course was complicated by a cardioembolic cerebrovascular accident. She was eventually discharged home on medical management consisting of a beta-blocker, angiotensin-converting enzyme inhibitor, loop diuretic, and statin.

At the time of presentation to our hospital, her physical examination was positive for elevated jugular vein pressure and distention, a systolic ejection murmur, bilateral crackles and wheezing, 3+ pitting edema up to the knees bilaterally, and multiple skin ulcerations. An electrocardiogram demonstrated normal sinus rhythm, low-voltage QRS with poor R wave progression, residual anterior ST elevation, and Q waves in leads I and aVL. Chest x-ray showed a left pleural effusion. Laboratory evaluation was significant for a brain natriuretic peptide level of 6249 pg/mL and troponin T level of 0.02 [micro]/L. Her serum cholesterol was 99 mg/dL and triglycerides, 103 mg/dL. Subsequent cardiac catheterization revealed a cardiac index of 1.3 L/min/[m.sup.2], consistent with cardiogenic shock. Her arterial blood pressures were in the 80s to 90s mm Hg systolic and 60s mm Hg diastolic. Initiation of dobutamine increased her blood pressure to the 100s mm Hg systolic and 70s mm Hg diastolic.

Impressions from TTE were severe LV dysfunction, extensive distortion of the LV apex presumably related to an extensive aneurysm filled with thrombus, and diastolic inward movement of the thrombus in the aneurysm. A mass was seen anterior to the heart overlying the right ventricle (RV) and was determined to likely represent thrombus or possible contained myocardial rupture next to an aneurysm. Finally, there was compression of the RV free wall from the mass/thrombus. Referral for magnetic resonance imaging (MRI) was recommended.

Cardiac MRI showed RV compression by a large clot, severely depressed (14%) LV function, moderately depressed (38%) RV with obliteration of the RV cavity, and a large thrombus contained within the pericardium compressing the RV from the mid RV to the apex. In addition, there was pericardial enhancement outside the posterior portion of the RV that was consistent with a pseudoaneurysm.

An intraaortic balloon pump was placed immediately prior to presenting to the operating room for a planned Dors procedure (8), which is an LV patch plasty, and a coronary artery bypass graft. After successful induction of anesthesia, a TEE was performed. The estimated ejection fraction was 20% to 25%, and severe tricuspid, mild pulmonary, and mitral regurgitation and mild aortic insufficiency were noted. A large pseudoaneurysm was visualized compressing the RV and LV (Figure 2). The identification was made based largely upon the lack of myocardial continuity within the aneurysmal wall.

A midline sternotomy was performed with careful entry into the pericardium. After cannulation of the aorta, right atrium, and superior vena cava, the pseudoaneurysm was entered with immediate initiation of cardiopulmonary bypass (CPB). The pseudoaneurysm was described as being the size of a grapefruit, measuring approximately 10 to 15 cm in diameter. The pseudoaneurysm was thought to be old and not acute. After debridement of the pseudoaneurysm, a true aneurysm measuring approximately 5 x 8 cm in diameter was visualized.

The surgeons decided to keep the heart warm and beating during the procedure. The scheduled coronary artery bypass graft was aborted because of poor visualization of the targets for the left anterior descending artery, marginal, and RV branches secondary to complete encasement of the ventricular surface. They proceeded with the Dor procedure. After a CPB time of 147 minutes, separation was achieved for approximately 10 minutes, at which time the patient became hemodynamically unstable, requiring reinitiation of CPB. Although the RV ejection fraction was not quantified, it was clinically evident by regional RV wall motion abnormalities and inadequate LV filling. An RV assist device was placed, and separation from CPB was achieved with high ionotropic support consisting of epinephrine, norepinephrine, and dobutamine. She was also initiated on nitric oxide, 40 parts per million, for pulmonary artery systolic pressures ranging from 60 to 80 mm Hg. TEE revealed no new regional wall motion abnormalities. The remaining perioperative course was complicated by coagulopathy, multiple organ failure, and death.

[FIGURE 2 OMITTED]

Surgical pathology reported the specimen as consisting of fragmented, hemorrhagic, fibrous tissue, measuring 21 x 15 x 4 cm in aggregate. No definite ventricular wall was identified, but there was hemorrhagic tissue which measured 0.2 to 1.0 cm in thickness. The remainder of the tissue was blood clot. The specimen was reported as being consistent with a pseudoaneurysm.

DISCUSSION

Our case of concurrent LV pseudoaneurysm and true aneurysm is indeed rare, with only limited reports in the literature (9, 10). Although rare, pseudoaneurysms represent a life-threatening complication of MI necessitating urgent surgery. In our case, a TTE had shown an extensive aneurysm but wasn't able to delineate it further, and a cardiac MRI had to be performed. The MRI reported the likely possibility of a pseudoaneurysm.

Acquiring optimal precordial images on TTE can be limited by mechanical ventilation, obesity, suboptimal positioning, and/or lines and tubes. TEE may provide a way around these technical limitations (11). This is particularly important because identifying the continuity of the myocardium is a challenging yet distinguishing feature in pseudoaneurysms in comparison to true aneurysms (4).

Cardiovascular derangement occurs in more than 20% of cardiac surgical patients (12). Another benefit of TEE performed during surgical repair and after weaning from CPB is the evaluation for improvements, especially the ejection fraction (4). Although LV failure is mostly studied and assessed, acute RV failure is a major cause of morbidity and mortality. Thus, a comprehensive assessment of RV size, shape, and function may lead to early management of RV failure, making TEE the mainstay in the assessment of perioperative RV function (13).

Although some authors advocate for multimodal cardiac imaging (14), in institutions where advanced technology is limited, precluding the use of MRI for example, TEE is considered superior to TTE in distinguishing between a true aneurysm and pseudoaneurysm (6,7,15). TEE's portability and ease of examination are added advantages over MRI (16).

Two-dimensional echocardiography can be further enhanced with three-dimensional echocardiography, with one report that suggests better delineation of the size and shape of the rupture site, making it feasible to assess the longitudinal and transverse dimensions, circumference, and area of the rupture site. Additionally, it allows for visualization of the mitral annulus and papillary muscles, which can guide surgical management by assessing severity and/or improvement, possibly precluding the need for mitral valve repair or replacement (17).

In conclusion, with the use of intraoperative TEE, we had the ability to confirm the diagnosis of pseudoaneurysm, evaluate cardiac function before, during, and after surgery, and diagnose RV failure, guiding surgical management.

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Erica N. Grant, MD, Norman Huang, DO, Girish P. Joshi, MD, and Marco A. Aguirre, MD

From the Department of Anesthesiology and Pain Management, The University of Texas Southwestern Medical Center, Dallas, Texas.

Corresponding author: Erica N. Grant, MD, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9068 (e-mail: Egrn1998@yahoo.com).
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