Inverted left atrial appendage mimicking potential left atrial thrombus in an infant following cardiac surgery: a case report.

Background: Inverted left atrial appendage (iLAA) is an infrequent complication following cardiac surgery, seen both in children and adults. Following a recent encounter, this review article is aimed to remind the reader about its occurrence, clinical manifestations, differential diagnoses, and management options. Case summary: A 3-month-old baby underwent successful surgical repair of a large ventricular septal defect. Intraoperative epicardial echocardiogram at the end of the case demonstrated an unexpected left atrial mass, raising suspicion of a thrombus adjacent to the mitral valve. Urgent re-establishment of cardiopulmonary bypass and exploration of the left atrium did not reveal a thrombus, but this was subsequently identified as an iLAA. This completely resolved after manual external reduction of the appendage. Discussion: Published literature is confined to case reports only, with most cases observed post-operatively, but some occurring spontaneously. Awareness of this unusual manifestation is particularly important in the intraoperative period as it can usually be addressed without the need for further cardiopulmonary bypass.

Modeling Alzheimer's disease using human cell derived brain organoids and 3D models.

Age-related neurodegenerative diseases, like Alzheimer's disease (AD), are challenging diseases for those affected with no cure and limited treatment options. Functional, human derived brain tissues that represent the diverse genetic background and cellular subtypes contributing to sporadic AD (sAD) are limited. Human stem cell derived brain organoids recapitulate some features of human brain cytoarchitecture and AD-like pathology, providing a tool for illuminating the relationship between AD pathology and neural cell dysregulation leading to cognitive decline. In this review, we explore current strategies for implementing brain organoids in the study of AD as well as the challenges associated with investigating age-related brain diseases using organoid models.