ROLES OF CARE AND VASCULAR INJURY

Each role of care has unique approaches to the management of vascular injury.4

Role 1 / Role 2

Role 1 – Point of injury hemorrhage control with Tactical Combat Casualty Care principals: Pressure dressings, tourniquet placement, wound packing, etc. Initiation of evacuation and safe handoff.

Role 2 – Most surgical interventions at forward operating locations are ‘damage control’ to prioritize restoration of physiology over anatomy. Abbreviated (<1 hour) operations should focus on restoration of patient physiology, restoration of vascular flow, and focused on life and limb saving procedures. Early intervention on extremity vascular injuries is important and may make the difference in meaningful limb salvage. While physiology restoration is always the first stage of managing vascular injury +/- polytrauma, the future operating environment might require Role 2 surgical teams to embark on subsequent definitive care depending on the deployed trauma system.

- Primary amputation or ligation is also an acceptable damage control technique when other life-threatening injuries are present, or the patient is in extremis.
- If limb salvage is attempted, initiation of basic maneuvers including removal of tourniquet, exploration and control of the vascular injury, removal of clot (thrombectomy) and administration of heparinized saline through the inflow and outflow vessels are recommended. Venous injuries should be repaired after arterial inflow is restored. Data from combat casualties demonstrates high limb salvage with venous repair.
- Restoration of flow is most expeditiously established using a temporary vascular shunt, which expedites reperfusion and lowers the rates of amputation. This followed by having a low index of suspicion to perform a fasciotomy and then initiation of medical evacuation to a higher level of care (if possible) to optimize limb salvage.
- Temporary shunt placement for the initial management of proximal extremity vascular injury is associated with very high rates of successful limb salvage, and consistent shunt patency has been demonstrated for periods up to 12 hours.9,10,11 However, experience with shunt utilization without systemic anticoagulation for more prolonged periods is limited, and the risk of shunt thrombosis is markedly increased when used beyond 12 hours.8,12
- If a significant delay before definitive vascular management is anticipated, Role 2 surgeons should consider definitive management of the injury with repair/reconstruction (if appropriate equipment available, see Appendix F) or ligation, depending on the patient’s stability and the experience level of the surgeon. An option for more long-term temporary ‘shunting’ would be using a Gortex™ or Dacron ™ graft if available. This is a more ‘stable shunt’ and does not risk using vein when good autologous repair might be limited. Wartime arterial injury usually necessitates staged care; recent data demonstrates similar rates of limb salvage between staged interventions at Role 2 and initial management at Role 3.13
- When MEDEVAC to a Role 3 is readily and rapidly available, Role 2 surgeons should NOT perform definitive vascular repair/reconstruction as this may risk early graft failure during en-route care and may risk limb salvage opportunities and long-term functional outcomes.
- During evacuation, shunts should be backed up with tourniquets in the event they become dislodged during transport.

Role 2 surgeons must ensure safe transport after temporary shunting. The shunt must be secured in place - the best way to do this is securing ‘vessel to vessel’ and ‘shunt to vessel’ both proximally and distally. Additionally, en-route care providers must have a ‘rescue mechanism’ should the shunt be dislodged during transport. These techniques are taught in the ASSET+/Emergency War Surgery Course and photos below depict how to best secure a temporary vascular shunt.

Role 3

- Role 3 – In most circumstances, if clinically indicated, definitive vascular repair should be accomplished at the Role 3. Autologous vein, usually saphenous, is used to repair the injured artery. Venous repair should be attempted if the casualty’s physiology is amenable to a longer operation.
- Synthetic polytetrafluoroethylene (PTFE) conduit can be used in the absence of appropriate autologous vein, with appropriate soft tissue coverage and antibiotic administration.
- During aeromedical evacuation to the Role 4 (usually fixed-wing), the extremity will be difficult to examine, therefore Role 3 surgeons must assure adequacy of limb perfusion prior to transfer. There should be a low threshold to perform a fasciotomy if there is any question about compartment syndrome or an increased risk of compartment syndrome during transfer to Role 4.
- Penetrating wartime vascular injuries are almost universally associated with severe and contaminated soft tissue injuries. These wounds should be debrided daily in the initial phase of care and prior to transfer.
- Primary amputation or ligation is also an acceptable damage control technique at this echelon of care when other life-threatening injuries are present, or the patient is in extremis.

Role 4

- Outside Continental U.S. (OCONUS) Role 4 – Assessment of vascular repair including repeated evaluation (OR or bedside) of soft tissue wounds and adequacy of tissue coverage. Contaminated or extensive soft tissue injuries should go to the OR every day until there is no further evidence of myonecrosis or gross contamination. Wounds and vascular patency should be assessed within 24 hours prior to a long fixed-wing flight. Consideration should be made for replacement of prosthetic bypass material with autologous vein conduit.
- Continental U.S. (CONUS) Role 4– Surveillance of vascular repair with duplex or computed tomography-angiography (CTA) as well as assessment of soft tissue wounds and adequacy of tissue coverage is performed at this echelon.14 Angiography (computed tomography or conventional) has particular utility in the identification of more subtle vascular injuries (e.g., traumatic pseudoaneurysm, arteriovenous fistula) following blast injury.15 In some instances, revision of at-risk repairs is necessary when bypasses are identified as having a stenosis or inadequate tissue coverage leaving them prone to infection and blowout.16 Finally, delayed revascularization of viable but poorly perfused extremities, i.e. when ligation was performed as the initial method of management can be accomplished.