How to assess and treat peripheral arterial disease (PAD) caused by trauma

Peripheral arterial disease (PAD) in the lower extremities can be caused by atherosclerosis, aneurysm, or trauma. This article will cover the assessment and treatment of trauma-related arterial damage.

Traumatic arterial wall damage can be caused by a laceration or puncture from a broken bone that occurred during a fall or a motor vehicle accident. Another example is trauma from a knife or gunshot wound. Unfortunately, sometimes traumatic arterial damage is iatrogenic, meaning that it is caused by a physician during a procedure.

Let’s review the assessment and treatment of two potential outcomes of trauma-related arterial injury:

1. Acute limb ischemia (ALI)
2. Pseudoaneurysms

Traumatic arterial damage can cause ALI, which is clinically diagnosed with the five Ps:

1. Pain
2. Pallor (e.g., unhealthy, pale skin)
3. Pulselessness
4. Paresthesia (e.g., pins-and-needles sensation)
5. Paralysis

How to treat ALI

Acute limb ischemia is a surgical emergency because it can result in sudden necrosis. Usually, there is no time to obtain an ultrasound.

Confirmation of absent peripheral pulses on palpation can be performed with a portable Doppler pen. But, the patient is likely to go straight to the catheterization laboratory or the operating room.

Iatrogenic arterial wall trauma can occur during a procedure such as vessel catheterization. The catheter can accidentally penetrate the arterial wall causing blood to leak out into the surrounding tissue. This contained rupture is called a pseudoaneurysm.

A common iatrogenic pseudoaneurysm results from catheterization of the common femoral artery in the groin. It usually presents as a pulsatile mass in one side of the groin.

With a pseudoaneurysm, blood flows from the artery through the puncture and forms into a round collection of active blood flow. This blood collection is connected to the artery by a neck (e.g., a trail of blood between the artery and the blood collection).

The blood flow swirls within the pseudoaneurysm, creating a yin-yang color effect on an ultrasound. The neck is characterized by to-and-fro flow, meaning that the blood actively flows back and forth from the artery to the pseudoaneurysm.

Arterial duplex ultrasounds are useful for diagnosing pseudoaneurysms because they provide a direct image of the pseudoaneurysm that can be used for further evaluation.

How to treat pseudoaneurysms

In most cases, a small pseudoaneurysm that is not quickly expanding isn’t a surgical emergency. Most physicians wait and watch to see if the pseudoaneurysm becomes thrombotic on its own over the next one to two days.

If the pseudoaneurysm does not clot, there is the option of performing a 20-minute manual compression of the pseudoaneurysm’s neck. This procedure attempts to cut off blood flow from the artery and causes thrombosis of the pseudoaneurysm. Sometimes, the compression is done with the ultrasound probe to track progress.

Recently, the standard of care for pseudoaneurysms has become an injection of thrombin under ultrasound guidance. Thrombin causes the blood in the pseudoaneurysm to clot. Ultrasound is used to confirm the needle placement, visualize the injection, and ensure that there is no extension into the native artery (which can cause embolism).