Peripheral vascular trauma is more commonly observed during wartime but also occurs frequently in peacetime. Injuries to major vessels can lead to permanent functional impairment, limb loss, or even death, resulting in severe consequences.
Etiology
Direct injuries include sharp injuries, such as cuts, stabs, gunshot wounds, and open injuries caused by surgical or endovascular procedures; blunt injuries, such as crush injuries, contusions, external compression (e.g., tourniquets, bandages, or plaster casts), and injuries caused by fracture ends or joint dislocations, which are mostly closed injuries.
Indirect injuries include arterial strong and persistent spasm caused by trauma; vascular tears due to excessive stretching; and vascular concussion injuries caused by sudden deceleration during rapid movement.
Pathology
Disruption of vascular continuity is manifested by perforation, rupture, or even partial defect of the vessel wall.
Damage to the vessel wall without disruption of continuity can include adventitial damage, wall hematomas, intimal tears, or intimal folding, which may lead to secondary thrombosis and subsequent luminal obstruction.
Thermal vascular injury is common in gunshot wounds, often causing extensive burns to the vessel wall.
Secondary pathological changes include secondary thrombosis, surrounding hematomas, pseudoaneurysms, and traumatic arteriovenous fistulas, among others.
Clinical Manifestations and Diagnosis
Severe trauma involving any part of a major artery or vein may suggest vascular injury as a possibility. Common clinical manifestations include bleeding at the site of injury, shock (with concealed bleeding being more common in closed injuries), hematomas or pulsatile masses, and ischemia in distal limbs or organs.
The following examinations can assist in the diagnosis of vascular injury:
- Doppler Ultrasound: Useful for non-invasive identification of localized hematomas or pseudoaneurysms. It can also determine the presence or absence of blood flow within vessels.
- CTA (Computed Tomography Angiography): Provides details on the site and extent of vascular injury. It is more effective in identifying arterial injuries than venous injuries.
- Angiography: Applicable in the following situations:
- Diagnostic angiography: Performed when clinical signs of vascular injury are ambiguous, CTA is inconclusive, or direct exploration of potentially affected vessels through the traumatic wound is not feasible.
- Angiography for confirmation and planning: Used when clear clinical signs of vascular injury are present, to determine the exact location and scope, and to guide the selection of surgical techniques. Depending on the situation, angiography may be performed preoperatively or intraoperatively.
- Intraoperative Exploration: During surgery, the extent and severity of vessel wall injury are evaluated. Blunt trauma that results in vascular injury often presents with a dull appearance of the vessel wall, loss of elasticity, hematomas in the wall, and ecchymosis on the adventitia. These findings, even in the presence of pulsatility, should be classified as severe injuries.
Treatment
Management of vascular injuries involves emergency hemostasis and surgical treatment.
Emergency Hemostasis
Hemostasis is achieved by pressing a gauze-covered wound with compression bandaging. Proximal bleeding can be controlled with a tourniquet or pneumatic tourniquet, with clear records kept of the application time to ensure periodic relaxation. For visible injured vessels exposed in the wound, vascular clamps or atraumatic vascular clamps can be applied directly for hemostasis. Excessively high blood pressure should generally be avoided before bleeding is controlled, to prevent aggravation of the bleeding.
Surgical Treatment
The basic principles are hemostasis, debridement, and repair of the injured vessels.
Hemostasis and Debridement
Atraumatic vascular clamps or Fogarty catheters with inflated balloons inserted into the vascular ends may be used to occlude blood flow. Non-viable segments of the vessel wall are excised, and intraluminal thrombosis, tissue debris, and foreign bodies are removed.
Repair of Injured Vessels
Primary and secondary arterial or venous injury should be repaired whenever possible, provided the patient's condition and technical feasibility allow. For injuries to non-major vessels, or if the patient cannot tolerate vascular reconstruction, ligation of injured vessels may be conducted. Vessel repair can include the following methods:
- Lateral Suture Repair: Suitable for neatly edged vascular lacerations.
- Patch Angioplasty: When direct suturing results in luminal narrowing, repairs are made using autologous veins, synthetic grafts, or biological patches.
- End-to-End Anastomosis: Appropriate when the vessel defect, after debridement, measures less than 2 cm.
- Vascular Grafting: For defects greater than 2 cm, repair can involve autologous vein grafts or synthetic grafts. In cases of severe contamination, the use of autologous veins is preferred.
- Extraluminal Arterial Bypass: Applied in situations with severe wound contamination where in situ arterial reconstruction is not feasible.
If vascular injury is accompanied by fractures and limb ischemia, priority should be given to repairing the injured vessels. Endovascular treatments, including embolization or covered stenting, may be employed in cases such as peripheral arterial bleeding, arteriovenous fistulas, or pseudoaneurysms.
Postoperative Monitoring and Management
Postoperative assessment of blood supply is essential, with regular Doppler ultrasound evaluations. Any evidence of anastomotic stenosis or distal vascular obstruction may need timely correction. Symptoms such as severe limb pain, extensive swelling, sensory and motor dysfunction, unexplained fever, and tachycardia should raise suspicion for compartment syndrome, necessitating urgent fasciotomy for decompression.
Prophylactic antibiotics are routinely used during and after surgery to prevent infections. Wounds should be monitored every 24-48 hours; in cases of infection, early drainage and debridement of necrotic tissue are required.