Vascular Extremity Trauma

What is Vascular Extremity Trauma?

Damage to the blood vessels can lead to serious consequences. The first emergency repair of a blood vessel wound was performed by Dr. Hallowell on June 15th, 1759, following the advice of his colleague Dr. Richard Lambert. Dr. Lambert realised that mending the blood vessel without blocking it could prevent the health problems and deaths often caused by tying off blood vessels. At that time, most blood vessel injuries were either pseudoaneurysms, tears in the wall of the blood vessel, or abnormal connections between arteries and veins, often caused by bloodletting. Dr. Lambert believed that simple repair was more beneficial to the patient than tying off the blood vessel.

Blood vessel damage can occur in three ways: by blunt force, penetrating injuries, or a mix of the two. These injuries can happen in both civilian or military environments. Luckily, in everyday life situations, such injuries are rare in emergency rooms. Estimates suggest that injuries caused by penetrating objects to the limbs make up 5 to 15% of all traumas. However, blood vessel injuries account for only 1% of all trauma injuries to the limbs. Both the Western Trauma Association and the Eastern Association for the Surgery of Trauma have guidelines on how to assess and manage blood vessel injuries.

What Causes Vascular Extremity Trauma?

Injuries to the blood vessels, called peripheral vascular trauma, can happen in both civilian or military situations. These injuries can be broken down by how they occurred – either through blunt force, a penetrating object, or a combination of both – and by where they occurred, either in the upper or lower limbs.

Penetrating injuries occur when something sharp, like a bullet, fragment from an explosion, knife, or even household objects like coat hangers or keys, pierces the skin and damages the blood vessels. On the other hand, blunt injuries happen when there is a fracture or dislocation that damages the blood vessels.

Risk Factors and Frequency for Vascular Extremity Trauma

Vascular injuries, which can involve the body’s main blood vessels, account for 1% to 2% of all trauma injuries, but they also represent over 20% of deaths related to trauma. The most common type of these injuries, resulting from penetrating wounds to the limbs, makes up 75-80% of all peripheral vascular injuries. Half of these injuries are due to gun injuries, with stab wounds and shotguns causing the rest.

The most commonly injured arteries are the femoral or popliteal arteries, which are located in the leg, and the brachial artery in the arm. Other types of injuries, such as fractures, dislocations, and crush and traction injuries, are responsible for the remaining 5 to 25% of injuries.

In the military setting, the rate of these injuries has increased significantly, from as low as 0.4% in World War I to 12% in recent conflicts such as in Afghanistan and Iraq. The majority of these injuries, approximately 79%, are to the limbs, especially the lower limbs.

Meanwhile, blunt force injuries to the blood vessels more commonly take place within the torso due to car accidents, but can also be associated with certain types of fractures or dislocations.

Vascular injuries are a prominent issue, making up 1-2% of all trauma injuries and significantly over 20% of deaths from trauma.
Most vascular injuries (75-80%) happen because of penetrating wounds in the limbs.
The femoral, popliteal, and brachial arteries are commonly affected
Falls, fractures, and dislocations also cause a number of these injuries.
The rates of these injuries in the military have increased over the years.
Most of these injuries affect the limbs, particularly the lower ones.

In a study of vascular trauma patients, the researchers found that males and individuals around 29 years old were more likely to have these injuries. There were more injuries in the central zone (an area including key vessels like the carotid and femoral arteries), followed by the extremity zone (vessels outside this central area). These injuries required more blood transfusions, longer hospital stays, and more intensive care management than general trauma injuries.

Another study focusing on pediatric patients found that the rate of vascular injury was 0.6%. The injured vessels were mostly the brachial, radial, and ulnar. Trauma-related mortality was lower in children than in adults, and this lower mortality rate was attributed to the fact that children tend to have more isolated injuries.

Moving on to elderly patients, they represented a small percentage (7.6%) of vascular trauma cases. However, their mortality rate was significantly higher than that of other age groups. Vascular injuries in the elderly were often caused by motor vehicle accidents and mainly affected blood vessels in the chest.

Signs and Symptoms of Vascular Extremity Trauma

The Advanced Trauma Life Support protocol is followed for all trauma patients. This includes checking the airway, breathing, and circulation. Vascular injuries, or injuries to blood vessels, are assessed based on hard and soft signs. These signs are defined differently by different associations, but typically include symptoms like swelling, bleeding, loss of pulse and external bleeding for hard signs, and history of arterial bleeding or nerve issues for soft signs.

Hard signs: swelling, lack of pulse, external bleeding
Soft signs: history of arterial bleeding, nerve issues

If hard signs are present, immediate operation is required. Soft signs, on the other hand, are evaluated after the primary evaluation is completed. Palpation, or feeling the pulse in the extremities, is an initial part of evaluating circulation. If there’s active bleeding, techniques like manual compression or a compressive dressing can be applied to control it.

If it appears that a limb has been severely damaged by trauma, a decision has to be made regarding whether it can be saved. A limb is considered mangled if there are injuries to three out of four functional components including vessels, tissue, bone, and nerves. There are several scoring systems to predict if a limb can be salvaged. One of them is the Mangled Extremity Severity Score (MESS), which takes into account age, type of injury, wound, and shock. A score higher than 7 usually indicates a need for amputation. However, these scoring systems are not always effective in predicting the need for amputation.

Testing for Vascular Extremity Trauma

When a patient arrives reporting of a trauma, standard lab tests are conducted immediately. Depending on the seriousness of the injury and the patient’s condition, relevant imaging may be carried out.

Frykberg and team conducted a study on 2,674 trauma patients in a year, out of which 366 had Penetrating Trauma Exposure (PTE) to find out if physical exam alone is accurate and safe for diagnosing vascular injuries. For penetrating injuries to the extremity, they concluded that if certain clear signs were present, it meant the patient had a major vascular injury and needed surgical intervention. Imaging techniques like arteriogram or ultrasound can be used if there is a need to locate the vascular defect. The quicker the perfusion is restored (preferably within 6 hours) the better chances of saving the limb.

Interestingly, normal pulse exams can be misleading as 5% to 15% of patients with vascular injuries may still present a normal pulse. Thus, measures beyond physical exams like Ankle-Brachial Index (ABI) or Arterial Pressure Index (API) are required. If the index equals 0.9 or more, no further imaging is required as the sensitivity and specificity are high.

Studies suggest that the CT Arteriography (CTA) method, which provides a more detailed view of the arteries, is highly reliable in evaluating traumatic arterial injuries of the extremities. The advantages of CTA are that it’s non-invasive, the procedure is quick and it’s readily available. However, it does have its downsides such as being unable to intervene, an increased need for larger intravenous contrast and delivering poor arterial opacification. According to the Eastern Association for the Surgery of Trauma (EAST), CTA is recommended as the preferred imaging technique based on level I evidence. Traditional arteriography is more invasive but can be done in the operating theater and allows immediate intervention. However, it doesn’t provide any additional value over a physical exam while being invasive and costly. Duplex ultrasound is another option for assessing vascular injuries but is limited by the need for skilled staff to operate and interpret the results. Its specificity is high at 95%, but sensitivity varies significantly.

Treatment Options for Vascular Extremity Trauma

When looking at images for diagnoses, certain findings like a throbbing blood clot, a leaking blood vessel or a pseudoaneurysm (an abnormal blood-filled bulge of a vein or artery), a blockage, or an abnormal communication between a vein and an artery call for immediate surgical interference. If these abnormalities are found in a less significant blood vessel, distinct measures like watching over time (blockage) or installing a beneficial blood clot via a procedure called therapeutic embolization (for abnormal communication or leakage) can be adopted. After 3 to 5 days, another scan or ultrasound is recommended to check for the development of a pseudoaneurysm or a pulsatile hematoma which can occur due to a backflow of blood.

If an initial injury or defect is identified in the images, it’s usually not alarming since 87% to 95% of these heal on their own without major surgical intervention. The patient might be recommended blood-thinning medication or aspirin as a preventive measure if there’s no other health risk. In case of sudden changes in blood flow to a limb or signs of abnormal communication or pseudoaneurysm, immediate imaging is needed.

In certain cases, the peripheral artery can experience spasms. This is usually visible on imaging and entails warming of the limb if there’s good blood flow. Other related issues like compartment syndrome (a severe condition caused by increased pressure in a muscle compartment), in situ thrombosis (an inside clot formation), or distal embolism (a blood clot that has traveled from its place of formation to another place in the body) should be taken into consideration and monitored. In severe cases of spasms, several intra-arterial treatments can be attempted using a range of medications and interventions.

Pre-operative preparation should take into account potential areas where surgical cuts would be required. Depending on the extent of the vessel injury, the surgery can range from a simple repair to more complex procedures involving an interposition graft (a kind of bypass surgery to redirect the blood flow around the damaged area) using autogenous (obtained from the same individual’s body) or artificial grafts. However, if a patient is not stable, temporary blood flow restoration measures are used.

If limb salvage is a treatment option, blood flow is first established by inserting a temporary intraluminal shunt, which is a short tube. After the shunt is removed, a graft or extra-anatomic bypass operation is performed. In cases of risk for compartment syndrome (a painful and dangerous condition caused by pressure buildup from internal bleeding or swelling of tissues), a surgical procedure to relieve this pressure, known as a fasciotomy, can be performed.

For gunshot wounds associated with fractures, there are no specific guidelines for antibiotic usage. Some doctors recommend antibiotics for low-velocity gunshot wounds if managed non-surgically, while others believe it’s not necessary. For high-velocity gunshot wounds, there’s a general agreement that debridement (cleaning of the wound) and antibiotic therapy is required even though definitive evidence is lacking.

When a person experiences either a blunt or penetrating injury, there are five different types of damage that could happen to their arteries. These five types include:

A full break in the wall of the artery, which can lead to bleeding or the formation of a false aneurysm (a blood-filled bulge in the vessel wall).
Damage to the innermost layer of the artery (the intima), which can cause hematomas (blood clots), flaps, or disruptions.
The formation of an arteriovenous (AV) fistula, which is an abnormal connection between an artery and a vein.
A full cut across the artery, which can cause bleeding or blockage of the artery.
A spasm, or sudden contraction, of the artery.

Blunt injuries are most often related to damage to the innermost layer of the artery. On the other hand, penetrating injuries are more likely associated with a full break in the wall of the artery, a full cut across the artery, or the creation of an AV fistula.

What to expect with Vascular Extremity Trauma

In general, patients with serious injuries to their arms or legs can typically safely go home if their pulses at the wrist (or ankles) are strong and equal on both sides, or if certain measurements of blood flow in the injured limb are normal. This also applies to patients who’ve had procedures to correct knee dislocations. However, these patients should follow up closely with their doctors, as around 1% to 4% may see their small injuries grow worse over time, requiring surgery.

Also note that in one study, it was found that the average time it took between the injury occurring and its diagnosis was 10 days. So, it’s important to get your injuries checked out as soon as possible.

Possible Complications When Diagnosed with Vascular Extremity Trauma

Acute compartment syndrome is a serious potential consequence of penetrating trauma. This is a very serious medical emergency as it can stop blood flow to the tissue and eventually cause the tissue to die. Commonly, reversible nerve damage (neuropraxia) might happen if the tissues do not get sufficient blood supply for an hour. If this lack of blood supply extends to the four-hour mark, it could bring about irreversible nerve damage (axonotmesis) and, worse, over six hours, tissue death (necrosis) occurs and becomes irreversible.

Compartment syndrome can happen in various parts of the body including the lower leg (below the knee), thigh, forearm, and arm. Among these, it’s most common in the lower leg. Research has shown that the risk of compartment syndrome can be predicted based on the injury site. A trauma site higher up on the lower leg near the knee (tib/fib fracture) has a higher risk compared to one further down near the middle or the foot. The leading cause of compartment syndrome is fractures to the lower leg. Particularly patients who have both venous and arterial system injuries are at high risk.

It can be complex to diagnose acute compartment syndrome, especially in trauma patients, because of multiple co-existing issues. Classically, medical education teaches the 6 ‘P’s’ of diagnosis – pain, pallor (paleness), pulselessness, poikilothermia (variable temperature), paresthesia (abnormal sensations), and paralysis. Although, data supporting the usage of these ‘P’s’ in diagnosing acute compartment syndrome is limited. Typically, disproportionate pain to the injury is reported early. Physical examination might include trying to stretch the toe or finger to check for pain, which is often the earliest sign. Some propose that the inability to discern two distinct points of touch is another early sign. However, these clinical signs have been found to have low rates of accurately diagnosing the syndrome.

Furthermore, the firmness of the affected area as an indicator of compartment syndrome was investigated but it was concluded that feeling the area is not a reliable method. So, even if a fracture is open, ongoing careful monitoring is advised, as the issue could still arise. Compartment pressures can be directly measured with a handheld tool (Stryker device). If the difference in pressure is less than 30 mmHg, a surgical procedure to relieve pressure (fasciotomy) is needed. Also, one more thing to keep in mind is that fragments of lead in joint fluid can dissolve and cause lead poisoning.

Preventing Vascular Extremity Trauma

Some origins of penetrating vascular injuries, including gunshot wounds, can be minimized or even prevented through improved gun safety. For instance, when guns are present in the home, they should be securely stored and kept out of children’s reach. This is a conversation that should be held between the patient and their primary care doctor, or between parents and their child’s pediatrician.

Frequently asked questions

Vascular Extremity Trauma refers to injuries to the blood vessels in the limbs, which can occur due to blunt force, penetrating injuries, or a combination of both. These injuries are relatively rare in emergency rooms, accounting for only 1% of all trauma injuries to the limbs. Guidelines for assessing and managing blood vessel injuries are provided by the Western Trauma Association and the Eastern Association for the Surgery of Trauma.

Vascular extremity trauma, or injury to blood vessels in the leg, accounts for 75-80% of all peripheral vascular injuries.

The signs and symptoms of Vascular Extremity Trauma (Injury to Blood Vessels in the Leg) include: - Hard signs: - Swelling - Lack of pulse - External bleeding - Soft signs: - History of arterial bleeding - Nerve issues These signs and symptoms are used to assess vascular injuries in trauma patients. Hard signs indicate the need for immediate operation, while soft signs are evaluated after the primary evaluation is completed. Palpation, or feeling the pulse in the extremities, is an initial part of evaluating circulation. If there is active bleeding, techniques like manual compression or a compressive dressing can be applied to control it. In cases where a limb has been severely damaged by trauma, a decision needs to be made regarding whether it can be saved. A limb is considered mangled if there are injuries to three out of four functional components including vessels, tissue, bone, and nerves. Scoring systems like the Mangled Extremity Severity Score (MESS) can be used to predict if a limb can be salvaged. A score higher than 7 usually indicates a need for amputation, but these scoring systems are not always effective in predicting the need for amputation.

Vascular Extremity Trauma (Injury to Blood Vessels in the Leg) can occur through penetrating wounds, such as gunshot or stab wounds, to the femoral or popliteal arteries in the leg.

The doctor needs to rule out the following conditions when diagnosing Vascular Extremity Trauma (Injury to Blood Vessels in the Leg): - Full break in the wall of the artery - Damage to the innermost layer of the artery (the intima) - Formation of an arteriovenous (AV) fistula - Full cut across the artery - Spasm, or sudden contraction, of the artery.

The types of tests that are needed for Vascular Extremity Trauma (Injury to Blood Vessels in the Leg) include: - Standard lab tests - Imaging techniques such as arteriogram or ultrasound to locate the vascular defect - Ankle-Brachial Index (ABI) or Arterial Pressure Index (API) to assess blood flow - CT Arteriography (CTA) for evaluating traumatic arterial injuries - Duplex ultrasound for assessing vascular injuries - Scans or ultrasounds after 3 to 5 days to check for the development of complications like pseudoaneurysm or pulsatile hematoma - Intra-arterial treatments for severe cases of spasms - Pre-operative preparation to determine the extent of the vessel injury and plan the surgery - Temporary blood flow restoration measures if the patient is not stable - Intraluminal shunt insertion and graft or bypass operation for limb salvage - Fasciotomy to relieve pressure in cases of compartment syndrome - Debridement and antibiotic therapy for high-velocity gunshot wounds.

The treatment for Vascular Extremity Trauma (Injury to Blood Vessels in the Leg) depends on the severity of the injury. If there are certain findings like a throbbing blood clot, a leaking blood vessel, a blockage, or an abnormal communication between a vein and an artery, immediate surgical interference is necessary. However, if the abnormalities are found in a less significant blood vessel, measures like watching over time or therapeutic embolization can be adopted. In cases where an initial injury or defect is identified, most of them heal on their own without major surgical intervention. Blood-thinning medication or aspirin may be recommended as a preventive measure. In certain cases, peripheral artery spasms can occur, and warming of the limb is usually recommended if there's good blood flow. Other related issues like compartment syndrome, in situ thrombosis, or distal embolism should be monitored. The extent of the vessel injury determines the type of surgery required, ranging from simple repair to more complex procedures involving bypass surgery. Temporary blood flow restoration measures are used if the patient is not stable. If limb salvage is an option, temporary intraluminal shunt insertion followed by graft or bypass operation is performed. In cases of risk for compartment syndrome, a surgical procedure called fasciotomy can be performed. For gunshot wounds associated with fractures, the usage of antibiotics depends on the type and severity of the gunshot wound.

When treating Vascular Extremity Trauma (Injury to Blood Vessels in the Leg), there can be several side effects and considerations, including: - Immediate surgical interference may be necessary for certain findings like a throbbing blood clot, a leaking blood vessel, a pseudoaneurysm, a blockage, or an abnormal communication between a vein and an artery. - Distinct measures like watching over time or therapeutic embolization may be adopted for less significant abnormalities in blood vessels. - After 3 to 5 days, another scan or ultrasound is recommended to check for the development of a pseudoaneurysm or a pulsatile hematoma. - In most cases, initial injuries or defects heal on their own without major surgical intervention. - Blood-thinning medication or aspirin may be recommended as a preventive measure in some cases. - Sudden changes in blood flow to a limb or signs of abnormal communication or pseudoaneurysm require immediate imaging. - Peripheral artery spasms can occur and may be treated with intra-arterial medications and interventions. - Pre-operative preparation should consider potential areas where surgical cuts would be required. - The extent of the vessel injury will determine the complexity of the surgery, ranging from simple repair to more complex procedures like interposition grafts. - Temporary blood flow restoration measures may be used if the patient is not stable. - Limb salvage treatment options may involve temporary intraluminal shunts, grafts, or extra-anatomic bypass operations. - Compartment syndrome, in situ thrombosis, and distal embolism should be monitored and considered in treatment. - Antibiotic usage for gunshot wounds associated with fractures may vary depending on the type and severity of the wound. - Acute compartment syndrome is a serious potential consequence of penetrating trauma and requires immediate medical attention. - Compartment syndrome can occur in various parts of the body, with the lower leg being the most common site. - Diagnosing acute compartment syndrome can be complex, and the classic 6 'P's' of diagnosis may have limited accuracy. - Disproportionate pain to the injury, abnormal sensations, and paralysis may be early signs of compartment syndrome. - Firmness of the affected area is not a reliable indicator of compartment syndrome. - Compartment pressures can be directly measured with a handheld tool, and if the pressure difference is less than 30 mmHg, a surgical procedure to relieve pressure (fasciotomy) is needed. - Fragments of lead in joint fluid can dissolve and cause lead poisoning, so ongoing monitoring is advised even in open fractures.

Patients with serious injuries to their legs can typically safely go home if their pulses at the ankles are strong and equal on both sides, or if certain measurements of blood flow in the injured limb are normal. However, these patients should follow up closely with their doctors, as around 1% to 4% may see their small injuries grow worse over time, requiring surgery.

A vascular surgeon.