Zone of injury: a valid concept in microvascular reconstruction of the traumatized lower limb?

Microvascular reconstruction at the lower extremity for complex composite wounds has traditionally been predicated upon performance of the microanastamosis beyond the so-called "zone of injury." Failure to do so was believed to account for increased rates of vessel thrombosis and transplant loss. Extensive vessel dissection and vein grafts were often employed in efforts to avoid the zone of injury. To further analyze the validity of this concept, we conducted a prospective evaluation of all patients undergoing microvascular reconstruction of composite lower limb wounds during a 5-month period at Los Angeles County Medical Center. There were 28 patients in this cohort. Twenty-six (93%) were judged Gustilo IIIB or worse preoperatively. Distance from the microanastamosis to the proximal bony osteotomy (zone of injury) averaged 45.7 mm. In no case was a vein graft required. All transplants healed uneventfully without any loss. A reassessment of the concept of zone of injury is urged with analysis of the quality of the recipient vessels and not their location being clinically important.