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.