Left Ventricular Pseudoaneurysm Repair: A Case Report
Authors: Daniel Rothstein, PA-C, Michio Kajitani, MD, PhD, Mir Wasif
Ali, MD, FACS, Nahidh Hasaniya, MD, PhD
Dignity Health Medical Foundation Inland Empire Cardiothoracic Surgery
Dept
San Bernardino, CA
Article word count: 1193
Keywords: Pseudoaneurysm, ventricular wall rupture, myocardial
infarction
Corresponding author: Daniel Rothstein (415) 254-9931,
d.rothstein0422@gmail.com
Data availability: N/A as no new data were created or analyzed in this
study
Funding statement: none
Conflict of Interest: none
IRB Approval: N/A
Abstract
A 50 year old male with a history of myocardial infarction 3 months
prior presents to the emergency department with shortness of breath.
Diagnostic workup revealed a left ventricular pseudoaneurysm of the
inferolateral wall. Coronary artery disease and mitral valve
regurgitation were concomitantly identified. Surgical intervention on
these issues was successful. This case report highlights a rare but
important complication of myocardial infarction.
Introduction
Left ventricular pseudoaneurysm is a rare but challenging complication
following myocardial infarction (MI). This occurs when the ventricular
wall ruptures and the bleeding is contained by an adherent pericardium,
forming a contained cavity. This prevents uncontrolled bleeding into the
pericardium and subsequent tamponade. It has been reported in roughly
4% of MI patients and accounts for 23% of deaths related to
MI1, however, it is possible that many cases go
undetected because the initial presentation is sudden death. This type
of complication is associated with a high likelihood of rupture and
death, necessitating urgent surgical repair. Approximately 30-45% of
pseudoaneurysms will rupture.2 Pseudoaneurysm cavity
walls do not contain any myocardium. In contrast, true ventricular
aneurysms, which may also occur as a complication of MI, have a wide
mouth and outpouching of thinned ventricular wall (<5mm) that
still contain remnants of myocardial tissue2. Both
types of aneurysms can be accompanied by signs and symptoms of
congestive heart failure (CHF), angina, and dyspnea. Distinguishing
between the two diagnoses can be difficult. Patients can have ST-segment
changes on Electrocardiography (ECG) and enlarged cardiac silhouette on
chest x-ray. Physical exam may reveal a to-and-fro murmur, pericardial
friction rub, or muffled heart sounds. A new systolic murmur may be
present in 70% of patients.3 The diagnosis and
structural changes to the LV are confirmed by angiography and
echocardiography.
Case Report
A 50-year old male with a history of inferolateral MI three months prior
to admission, presented to the Emergency Department with shortness of
breath, orthopnea, and associated cough. Past medical history includes
CHF (EF 30-35%), schizophrenia, alcohol abuse, and polysubstance abuse.
He was not on any medications prior to his acute MI. The patient is a
difficult historian due to his psychiatric and substance abuse history,
but he reports compliance with his medications.
Physical exam showed jugular venous distention, bilateral lower
extremity 2+ pitting edema, bibasilar crackles and a systolic murmur
over the apex and left sternal border. All vital signs were stable.
Chest x-ray showed an enlarged cardiac silhouette. Computed tomography
(CT) scan revealed an outpouching of the left ventricle with a
distinctly separate cavity (figure 1). Echocardiogram showed a large
pseudoaneurysm with a 2.4 cm defect in the inferolateral wall of the
left ventricle and moderate to severe mitral regurgitation. Coronary
angiogram revealed an occluded circumflex artery with extensive disease
in the left anterior descending artery (LAD). The patient was referred
for surgical management.
Operative procedure
The patient underwent left ventricular pseudoaneurysm repair, coronary
artery bypass grafting connecting the left internal mammary artery to
the left anterior descending coronary artery, and a mitral valve
replacement with 27-mm Medtronic MosaicTM porcine
tissue valve. Primary cannulation technique was standard central
cannulation with a single venous cannula. Femoral cannulation was
prepared as a backup in case of uncontrolled bleeding during pericardial
dissection. A femoral arterial line was placed for accurate blood
pressure monitoring and potential for intra-aortic balloon pump or
percutaneous cannulation. A midline sternotomy was performed followed by
careful dissection of pericardial adhesions using electrocautery and
scissors. The patient was cooled down to 34o C after
adequate heparinzation and the aorta was cross-clamped. Cold blood
cardioplegia was given antegrade and retrograde. This was repeated every
20 minutes throughout the procedure. Dissection was continued to
delineate the pseudoaneurysm cavity on the posterolateral wall (figure
2). The pseudoaneurysm was entered and the defect repaired using a 2-0
ProleneTM running suture reinforced with strips of
TeflonTM felt on each side (figure 3).
Due to dense scarring that encased the multiple vessels, the LAD was the
only feasible target for bypass. Before completing the bypass, a left
atriotomy was made in order to examine the mitral valve. Upon visual
inspection and direct water injection, it was thought that the mitral
valve had become competent. The LAD graft was completed, the left
atriotomy was closed, and the patient was weaned off cardiopulmonary
bypass. The heart started beating in normal sinus rhythm.
Transesophageal echocardiography (TEE) showed persistent moderate mitral
regurgitation with tethering of the posterior leaflet, creating a large
eccentric jet. The cross clamp was re-applied, cardioplegia was
administered in the same manner, and the left atriotomy was re-opened.
The mitral valve was then replaced using a 27-mm Medtronic Mosaic
porcine tissue valve. Repeat TEE after coming back off bypass showed a
competent valve with no paravalvular leak.
Dissection of the pericardial adhesions created extensive bleeding from
the epicardial surface. Several topical hemostatic agents and blood
products were used to control the bleeding prior to closing the chest.
After adequate hemostasis, the chest was closed in the standard fashion
and the patient was transferred to the ICU in stable condition.
The patient was discharged home on post-operative day nine in stable
condition. He was evaluation in the clinic on post-operative day 23 and
was doing well.
Discussion
Distinguishing between a left ventricular pseudoaneurysm and a true
aneurysm is important in determining the need for surgical intervention.
True aneurysms do not always require surgical repair and can be treated
medically, whereas pseudoaneurysms require surgical repair due to a high
risk of rupture. The timing of surgical intervention is important to
improve patient outcomes. Current literature suggests that patients with
post-infarct ventricular rupture, that immediate surgical intervention
only be performed in the setting of hemodynamic
instability.4 If surgery can be delayed through
medical management or intra-aortic balloon pump, patients have
consistently better survival rates. The timing of this delay is not well
established and varied from as little as >3 days to as long
as >36 days. Early surgery relative to time of infarct is
associated with an in-hospital mortality rate of 52.4%, whereas delayed
surgery is associated with an in-hospital mortality rate of
7.6%4. This is attributed to the maturation of the
tissue surrounding the defect. The delay allows for myocardial fibrosis
to occur and creates more favorable tissue for surgical repair.
Angiography may be able to distinguish true aneurysms from false
aneurysms as well as, identify the need for concomitant bypass grafting.
Cardiac MRI with the use of gadolinium is the ideal imaging modality to
able to provide a definitive diagnosis.2
Follow up data on LV pseudoaneurysm patients is limited, however, an
analysis reported by Frances et al. showed that 25 patients (23%) died
at a median of three days postoperatively, but the surviving patients
survived to a median of 46 weeks. Of the patients that were treated
conservatively, 15 (48%) died at a median of less than one
week.3
The strategy to treat the accompanying mitral valve regurgitation can be
complicated. It is very tempting to repair or preserve the native mitral
valve, especially in younger patients, as was the case here. Ischemic
mitral valve regurgitation is notorious for less than optimal outcomes
when treatment by repair is attempted instead of replacement. In a
complicated case like this, we recommend early decision making to
proceed with replacement. This will shorten operative time and reduce
the risk of other complications related to prolonged cardiopulmonary
bypass time, such as excessive bleeding due to coagulopathy and multi
system organ failure, which can lead to prolonged hospital stay and even
death.
Conclusions
The survival of patients with pseudoaneurysms is low unless diagnosed
early and repaired surgically.
References
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