Pseudoaneurysm

A pseudoaneurysm, also known as a false aneurysm, is a collection of blood that forms between the two outer layers of an artery, the tunica media and the tunica adventitia. It is usually caused by a penetrating injury to the vessel, which then bleeds, but forms a space between the above two layers, rather than exiting the vessel. It may be pulsatile and can resemble a true aneurysm. A true aneurysm involves all three layers of the blood vessel. A dissecting aneurysm is when blood from the vessel lumen tracks between the two inner layers, the intima and the tunica media. This can cause blockage of the flow. A perivascular hematoma is a collection of blood that is external to the three vessel layers. Due to being close to the vessel, it can also be pulsatile, and can be mistaken for a pseudoaneurysm or aneurysm. A pseudoaneurysm, also known as a false aneurysm, is a collection of blood that forms between the two outer layers of an artery, the tunica media and the tunica adventitia. It is usually caused by a penetrating injury to the vessel, which then bleeds, but forms a space between the above two layers, rather than exiting the vessel. It may be pulsatile and can resemble a true aneurysm. A true aneurysm involves all three layers of the blood vessel. A dissecting aneurysm is when blood from the vessel lumen tracks between the two inner layers, the intima and the tunica media. This can cause blockage of the flow. A perivascular hematoma is a collection of blood that is external to the three vessel layers. Due to being close to the vessel, it can also be pulsatile, and can be mistaken for a pseudoaneurysm or aneurysm.