Hypoplastic left heart syndrome is a congenital cardiac abnormality that can be corrected surgically. This case is an example of the tissues received: atrial septum and ductus arteriosus. The surgical approach was the Norwood procedure (Sano modification, phase one). The first phase involved creating an atrial septal defect (LMP97925 and LMP59298 in related content), essentially bypassing the left heart. The ductus arteriosus is removed (this slide, and LMP56862 in related content) and a shunt is placed between the right ventricle and the pulmonary artery (as the Sano modification) (Sano et al. J Thorac Cardiovasc Surg. 2003 Aug;126(2):504-9). The classic Norwood procedure places the shunt between the aorta (or one of its branches) and the pulmonary artery

The atrial septal tissue is seen with layers of endocardium and muscle. The thrombus suggests a prior procedure may have been performed (such as balloon septoplasty).

The ductus arteriosus is morphologically unique from other vessels. The presence of the mucopolysaccharides in the intima and media (highlighted on the Movat) results in splayed out appearance of the tissue on the H&E. Such a morphology seen in other vessels would raise the suspicion of Marfan’s syndrome, among other differential diagnoses.

See related content for references:

1) Sano, S., et al. J Thorac Cardiovasc Surg. 2003 Aug;126(2):504-9.