After trauma or surgery, a non-atherosclerotic lesion appears as a swirling pocket of blood attached to the artery by a neck. What is this called?

After trauma or surgery, a non-atherosclerotic lesion appears as a swirling pocket of blood attached to the artery by a neck. What is this called?

• A. True aneurysm
• B. Post-traumatic pseudoaneurysm
• C. Dissection
• D. Hematoma

Answer: (B)

This scenario reflects a post-traumatic pseudoaneurysm, a false aneurysm. When the artery is injured, blood can escape into surrounding tissue but be contained by the adjacent structures rather than the vessel’s own wall. The resulting sac remains connected to the artery through a narrow neck, allowing ongoing blood flow into and out of the sac. Because the wall of this sac isn’t the normal arterial layers, it’s formed by surrounding tissues and possibly thrombus, not by all three layers of the vessel wall. This is different from a true aneurysm, which is a dilation that involves all layers of the vessel wall and is usually linked to degenerative processes like atherosclerosis. A dissection involves a tear in the intima that creates a false channel within the vessel wall itself, not a separate external sac. A hematoma is simply a collection of blood outside the vessel without a persistent connection to the arterial lumen. Imaging often shows a pulsatile sac with a neck and characteristic Doppler flow patterns feeding the sac, consistent with a pseudoaneurysm.

This scenario reflects a post-traumatic pseudoaneurysm, a false aneurysm. When the artery is injured, blood can escape into surrounding tissue but be contained by the adjacent structures rather than the vessel’s own wall. The resulting sac remains connected to the artery through a narrow neck, allowing ongoing blood flow into and out of the sac. Because the wall of this sac isn’t the normal arterial layers, it’s formed by surrounding tissues and possibly thrombus, not by all three layers of the vessel wall.

This is different from a true aneurysm, which is a dilation that involves all layers of the vessel wall and is usually linked to degenerative processes like atherosclerosis. A dissection involves a tear in the intima that creates a false channel within the vessel wall itself, not a separate external sac. A hematoma is simply a collection of blood outside the vessel without a persistent connection to the arterial lumen.

Imaging often shows a pulsatile sac with a neck and characteristic Doppler flow patterns feeding the sac, consistent with a pseudoaneurysm.