SOFT TISSUE COVERAGE & ANASTAMOTIC DISRUPTION

Pearls

- Cover vascular repairs with available viable local tissue (muscle and soft tissue pedicles).
- If no soft tissue to cover, route grafts out of zone of injury (extra-anatomic).
- A poorly covered vascular anastomosis or an anastomosis in an infected wound bed, can “blowout,” but not in the early (< 5 day) period.
- Avoid direct placement of negative pressure wound therapy sponge on vascular structures.
- Soft tissue coverage of vascular repairs is required to assure incorporation and prevent infection and blowout. Option 1 is to immediately cover the repair with viable local soft tissue (muscle and adipose). If available, the negative pressure wound therapy device (VAC) is useful on top of such coverage as it provides a closed dressing which removes wound effluent and decreases bacterial counts. This wound adjunct has been found to assist with accomplishing delayed primary closure of soft tissue wounds over vascular repairs or coverage with skin grafts. The reticulated open-cell foam sponge of the VAC should not be placed directly on vessels; however, when used over viable tissue covering the vascular repair, VAC has resulted in excellent outcomes with no increase in graft-related complications or blowouts.1 If there is no viable tissue option to cover the repair, the white foam vac dressing may be used to cover the vessel, but NEVER the black foam dressing.
- If no tissue is available to cover the vascular repair, one can route an interposition graft out of the zone of injury through another myocutaneous or even subcutaneous path (extra-anatomic). As a last resort, the vascular reconstruction can be left with marginal coverage at Role 2 and 3 facilities; however, in these cases close examination must occur at Role 4 facilities. In these rare instances higher levels of care should pursue transfer of viable tissue from other locations (sartorius, rectus abdominis or other muscle) to definitively cover the repair within 5-7 days. Although it is acceptable for Role 2 and 3 providers to leave a graft with uncertain coverage, the onus of care then falls heavily on Role 4 facilities to inspect, cover, re-route or even ligate the graft to reduce the risk of catastrophic blowout. When soft tissue coverage is not possible, consideration should be made for constant proximal tourniquet placement in the event of blowout and application by nursing or evacuation assets.
- It is important to recognize that even in the best of civilian and wartime circumstances that there has been historically and remains currently a finite risk of anastomotic disruption. Using the management strategies described above the risk of graft blowout has been within an acceptably low range of 1-2% throughout the wars in Iraq and Afghanistan.19,21

LARGE VEIN INJURIES

Pearls

- Formal control (DeBakey clamps) is acceptable but may be difficult or not advisable as it risks causing injury or may not be needed if injury is limited to the side wall of the vein.
- Initial control can be accomplished by one or more fingers on the bleeding segment.
- Organize the operating room and confirm availability of blood and central venous access.
- Central venous access above the heart if operating on injury to the inferior vena cava. If operating on an injury in the chest, central venous access is ideally at the femoral vein.
- Optimal lighting, exposure (i.e. extend incisions) and two or more suction devices.
- Avoid too small of a needle and suture which are difficult to maneuver in blood. 4-0 Prolene on an SH tapered needle is substantive suture on a needle large enough to see.
- Fingers replaced with a low profile tampanode device such as a small sponge stick or Wecksorb “K” dissector (i.e. Kitner device) as bleeding is evacuated.
- Passes of suture are made capturing muscle or soft tissue if possible (i.e. pledget-effect). Tie the knot to begin running venorrhaphy or place second pass in “figure-of-8” fashion.
- Felt pledgets can be used but may not be available.
- Hemorrhage control with ligation is preferable to patency with death from exsanguination.