In 1950, vascular involvement of penetrating extremity injuries usually lead to 50% chance of amputation. Now, usually < 5%.
First assessment on extremity injury is looking for arterial injury. Check color, temp, cap refill (cap refill not very sensitive though). ABIs: Doppler BP to all 4 extremities. Best upper extremity BP used. Equation is affected lower extremity BP / best upper extremity BP. Normal ABI should be > 1. If lower, need to consider arterial involvement. Also can put BP cuff proximal to injury and check doppler distal to injury.
Hard signs: 90% chance of arterial injury: absent/diminished pulses, obvious arterial bleeding, large expanding or pulsatile hematoma, audible bruit, palpable thrill, distal ischemia.
Soft signs: 35% risk of arterial injury: small, stable hematoma, unexplained hypotension, history of hemorrhage, proximity of injury to major vascular structures.
Xray joints above and below suspected injury. CTA is noninvasive, test of choice for assessing vascular involvement, though angiography is ‘gold standard.’ CTA is 98-100% specific, 90-95% sensitive. Doppler is good, though hard to assess for intimal flap or pseudoaneurysm.
50% of peripheral nerve injuries have vascular component as well. Major neurvascular bundles: axillary artery / brachial plexus, brachial artery / median nerve, radial artery / mean and radial nerve, ulnar artery / ulnar nerve, femoral artery / femoral nerve, popliteal artery / tibial nerve.
Popliteal artery: consider with complete ligamentous disruption of knee – likely has reduced knee dislocation. CTA usually recommended along with ABIs.
Subclavian artery: physical exam and CXR will show hemothorax, pneumothorax, apical pleural cap or wide mediastinum. CTA for better accuracy.
Arterial injuries need to be repaired in 6 hours. Endovascular treatment with stents is becoming more mainstream.
Complications: monitor for signs of compartment syndrome after reperfused proximal vascular injury due to edema, free radicals, etc. Delayed thrombosis can occur months to years after previous stricture, intimal flap injury from previous fracture.
Bleeding: do not clamp or ligate. Direct pressure is best. If unable to control with direct sustained pressure, tourniquets can be used, though only safe if used for less than 6 hours. Wound management should be irrigation. Large mount of 500-1000mL of saline or water at least. Antiseptic wash is not recommended and shown to have any other benefit. High pressure irrigation recommend – can use 60mL syringe with 18g needle.
Organic material more prone to infection compared to inert material like bullets/metal.
Joint involvement usually requires ortho consult for wash-out with stab/GSW. Bone fractures from penetrating injuries should be treated as open fractures.
Patients with penetrating injury with no arterial injury, no bony or nerve injury, minimal soft tissue defect and no signs of compartment can be discharge with close followup instructions. Knife/GSW soft tissue wounds are low risk for infection and prophylactic abx not recommended.
Tintinalli, Seventh Edition, Chapter 263: Penetrating Trauma to the Extremities
Rosens, Chapter 41: Peripheral Vascular Injuries