Zone of Injury

Abstract

The response of tissue to trauma is difficult to define. The zone of injury is an area surrounding a wound that, though traumatized, may not appear nonviable at initial debridement. Because of this, a policy of repeated debridements has been followed to monitor tissues for viability before final tissue coverage. Appreciation of the zone of injury has led to a controversy in the literature about how to define and approach the management of traumatic injuries requiring free-tissue coverage. This review examines the current literature with regard to the definition of the zone of injury, and seeks to establish a consensus statement about the application of free flaps to traumatized wounds. We have investigated the literature supporting the use of free flaps relying on proximally or distally based recipient vessels. Critical appraisal of this literature includes study design, determination of the power of the study, subject classification, inclusion and exclusion criteria, follow-up, and outcomes (free flap success). There has been little attempt in the literature to fully and objectively define the zone of injury. All studies to date have been observational alone. Although it would be impossible to rid a definition of the zone of injury of subjectivity entirely, a more objective, reproducible definition is vitally needed. Without a clear definition of what the zone of injury is, there can only be anecdotal, technique reports of the placement of free flap anastomoses. In this time of rising costs and lower reimbursements, this is one area that could provide vital information to improve care for patients, lessen costs, and further medical knowledge.

Blunt Trauma Induced Closed Femoral Bone Fracture in a Rat Model: Are Vessels Safe to Use for Microsurgery? Further Insight into the Zone of Injury Concept

“…It has been claimed that the definition of the zone of injury is still unclear and not easily reproducible. [9,10]. Changes within the zone of injury, such as increased friability of vessels and increased perivascular scar tissue, can make it difficult to dissect recipient vessels and may lead to a higher incidence of thrombosis after anastomosis.…”

Reconstructing complex peripatellar defects using the descending genicular artery perforator flap

“…The zone of injury is an area surrounding a wound that consists of gross inflammatory response of soft tissue and results in perivascular and endothelial changes. 30 Thus, the vessels in this zone are hypercoagulable and presumably negatively associated with flap success. Recent experience from free flap surgeries for complex lower limb reconstructions suggests that the recipient vessels distal to the zone of injury can be safely used for free flap reconstructions.…”

“…The trauma zone concept restricts the liberal use of locoregional flap for lower limb defects from high‐velocity trauma. The zone of injury is an area surrounding a wound that consists of gross inflammatory response of soft tissue and results in perivascular and endothelial changes 30 . Thus, the vessels in this zone are hypercoagulable and presumably negatively associated with flap success.…”

Using Duplex Ultrasound for Recipient Vessel Selection

“…The exact definition of zone of injury still remains unclear and unreproducible. 37 38 However, this concept is clinically important as thrombogenic zone is known to extend beyond what is macroscopically evident and failure to recognize the true extent of this zone is cited as a leading cause of microsurgical anastomotic failure. 29 38 One logical approach would be to search the recipient vessel proximal or distal to the zone where the tissue would be less scarred and well preserved.…”