Purpose: Tissue expansion of free flaps prior to transfer serves to increase the size of the transferred tissue and allows for primary closure of the donor site. Preexpansion is useful particularly in the burn patient with a large surface defect, and in the pediatric population, in which there may be a lack of adequate tissue and less toleration for a donor site defect. We present a case of a preexpanded scapular/parascapular free flap for coverage of a near-circumferential defect of the upper extremity following excision of a burn scar contracture in a 12-year old girl.
Materials & Methods: A 12-year old girl, presenting with history of a burn injury to the right upper extremity as a toddler resulting in a cicatricial burn scar contracture over the antecubital fossa extending to the olecranon and a 30 degree extension deficit at the elbow, underwent placement of two tissue expanders over the right parascapular region. One 500 cc expander was placed superiorly and one 250 cc expander was placed inferiorly and interval expansion over a 12-week period resulted in an expansion volume of 1300 cc and 760 cc, respectively. A scapular/parascapular flap of 22 x 26 cm was able to be harvested and transferred to fill a tissue defect of 20 x 25 cm after excision of the burn scar. Microvascular anastomosis was performed end-to-side to the brachial artery and basilic vein. The donor site was closed primarily over closed-suction drains.
Results: The scapular/parascapular flap healed well except for a 3 x 4 cm area of superficial ischemia due to tension that improved once the staples at the distal margin were removed. Subsequent re-elevation and inset of the flap resulted in full coverage of the defect area. The donor site healed without complications. With postoperative physical therapy, the patient was able to achieve full elbow extension.
Conclusion: Although not commonly used, preexpansion of free flaps allows for incorporation of a larger area of tissue for transfer and closure of the donor site primarily. Tissue expansion not only results in mechanical stretching of the tissue leading to a larger and thinner flap but also creates a delay phenomenon resulting in improved flap perfusion and ischemic endurance. These advantages offset the requirements of a two-stage procedure and the time period associated with the tissue expansion process when coverage of large defects is necessary.