Case presentation:
A 3-week-old neonate weighing 3400 grams, was brought to the emergency
department of a pediatric hospital. The neonate who was delivered with
no relevant birth details, has recently suffered from severe respiratory
distress symptoms, and was admitted and promptly intubated in that
hospital. Chest-x ray (CXR) showed a well-delineated (mass) on the left
border of the heart extending to the left hemithorax, and causing
complete compression of the left inferior pulmonary lobe (Figure-1). TTE
revealed massive dilatation of LA (LA aneurysm) about 8 cm with moderate
to severe mitral regurgitation (MR). CTA was performed to precisely
evaluate the LA aneurysm, its relation with the left ventricle (LV), and
the condition of the pulmonary veins and other surrounding structures
(Figure-2-A, Figure-2-B). Depending on the clinical state of the
patient, surgical intervention was scheduled on urgent basis. Median
sternotomy approach was used. Upon opening the pericardium, the heart
protruded outside the chest, and the LA appendage was apparent and
intact (it was not part of the aneurysm) (Figure-3). Total
cardiopulmonary bypass (CPB) with bicaval cannulation was prepared, and
the heart was arrested by antegrade cold blood cardioplegia. The heart
was lifted outside the pericardium and rightward (as in the repair of
total anomalous pulmonary venous connection), and the aneurysm was found
posteriorly and on the left side with very thin wall. The aneurysm was
opened, and its communication with LA was confirmed (Figure-4). The left
atrial appendage was not the origin of the aneurysm; however, it was
originating from the posterior wall of the LA near the posterior mitral
annulus. The aneurysm was of sessile nature, and extended to the
posterior wall of LV adjacent to marginal arteries. It was completely
resected, with special attention to avoid injury to the mitral annulus
or any of the marginal arteries. The resulted defect was closed by two
layers of running 7/0 prolene suturing (Figure-5). The LA was opened as
in mitral surgery, and mitral valve was inspected. The leaflets and
subvalvar apparatus were normal. The valve was tested by saline test and
was completely competent. Aortic cross clamp was released, and weaning
off CPB was uneventful. The patient was discharged from the hospital
after 21 days with significant clinical improvement, and normal
echocardiography.