Most common cause of pseudoaneurysm –
**Core Concept**
A pseudoaneurysm, also known as a false aneurysm, is a leakage of arterial blood from an artery into the surrounding tissue, which is contained by a wall of organized blood clot and granulation tissue. This condition is often caused by a disruption in the arterial wall, leading to the formation of a communication between the arterial lumen and the surrounding tissue.
**Why the Correct Answer is Right**
The most common cause of pseudoaneurysm is iatrogenic injury, which occurs during a medical procedure such as arterial cannulation or catheterization. This type of injury can disrupt the arterial wall, leading to the formation of a pseudoaneurysm. The mechanism involves damage to the arterial wall, which allows blood to leak into the surrounding tissue, and the body's natural response to form a wall of organized blood clot and granulation tissue to contain the leakage.
**Why Each Wrong Option is Incorrect**
**Option A:** Traumatic injury is a possible cause of pseudoaneurysm, but it is not the most common cause. Traumatic injury can also lead to the formation of a pseudoaneurysm, but the underlying mechanism is similar to iatrogenic injury.
**Option B:** Infection is not a direct cause of pseudoaneurysm, although it can complicate the condition. Infection can lead to the formation of an abscess or a collection of pus, but it is not the primary cause of pseudoaneurysm.
**Option C:** Atherosclerosis is a condition that affects the arterial wall, but it is not a direct cause of pseudoaneurysm. Atherosclerosis can lead to the narrowing or hardening of the arterial wall, but it does not typically cause the formation of a pseudoaneurysm.
**Clinical Pearl / High-Yield Fact**
Pseudoaneurysm can be life-threatening if left untreated, as it can lead to severe bleeding or rupture. Prompt diagnosis and treatment are essential to prevent complications and ensure patient safety.
**Correct Answer:** A. Iatrogenic injury is the most common cause of pseudoaneurysm, often occurring during medical procedures such as arterial cannulation or catheterization.