Evaluation of pulmonary blood flow in bilateral bidirectional Glenn shunts: value of 4‐D flow cardiac magnetic resonance in the evaluation of pulmonary artery confluence stenosis

Bilateral bidirectional Glenn shunts are associated with the risk of developing pulmonary artery bifurcation stenosis, resulting in variable pulmonary blood flow to either lung. This could negatively impact the subsequent stages of the single ventricle palliation pathway. This report highlights the value of 4D flow sequence from the cardiac magnetic resonance imaging in demonstrating the pulmonary blood flow characteristics following a bilateral bidirectional Glenn procedure. Mapping the blood flow pattern and its quantification to each lung provide objective insights into the possible predisposing factors for the development of pulmonary bifurcation stenosis.     

Nox2 underpins microvascular inflammation and vascular contributions to cognitive decline

Chronic microvascular inflammation and oxidative stress are inter-related mechanisms underpinning white matter disease and vascular cognitive impairment (VCI). A proposed mediator is nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (Nox2), a major source of reactive oxygen species (ROS) in the brain. To assess the role of Nox2 in VCI, we studied a tractable model with white matter pathology and cognitive impairment induced by bilateral carotid artery stenosis (BCAS). Mice with genetic deletion of Nox2 (Nox2 KO) were compared to wild-type (WT) following BCAS. Sustained BCAS over 12 weeks in WT mice induced Nox2 expression, indices of microvascular inflammation and oxidative damage, along with white matter pathology culminating in a marked cognitive impairment, which were all protected by Nox2 genetic deletion. Neurovascular coupling was impaired in WT mice post-BCAS and restored in Nox2 KO mice. Increased vascular expression of chemoattractant mediators, cell-adhesion molecules and endothelial activation factors in WT mice post-BCAS were ameliorated by Nox2 deficiency. The clinical relevance was confirmed by increased vascular Nox2 and indices of microvascular inflammation in human post-mortem subjects with cerebral vascular disease. Our results support Nox2 activity as a critical determinant of VCI, whose targeting may be of therapeutic benefit in cerebral vascular disease.     

Clinical Importance of Duplication of Internal Jugular Vein

Duplication of internal jugular vein (IJV) is rare. It is the larger channel draining the cranial cavity. We encountered duplication of the IJV while cervical node clearance in a patient with squamous cell carcinoma of left margin of the tongue. IJV divides into two parts anterior and posterior after descending about 2.5 cm from the jugular foramen. IJV is an important landmark in neck surgery. Knowledge of its variations is essential to avoid complications during surgery and to avoid misinterpretation in CT angiography.