Preoperative Long-term Therapeutic Subcutaneous Heparin Administration into Abdomen: Possible Cause for Nonobstructive Microvascular Flap Failure

Summary: The anterioabdominal wall is the most common site for low molecular weight heparin administration for anticoagulation, either for prophylactic or for therapeutic indications. Occasionally, this could be associated with damage of the abdominal pannus microvasculature, which could possibly jeopardize the reliability of free abdominal flaps as deep inferior epigastric perforator and muscle sparing transverse rectus abdominis muscle, especially with therapeutic anticoagulation therapy. These flaps are reliant on a highly intricate complex vascular anatomy and perforasomes for their adequate perfusion and survival. The authors report a case of nonobstructive microvascular failure of a free muscle sparing transverse rectus abdominis muscle utilized for soft tissue coverage following resection of a chest wall breast cancer recurrence on a background of portacath-induced deep venous thrombosis of the axillary and subclavian vein whilst on chemotherapy. History of long-term therapeutic low molecular weight heparin administration in the abdomen resulted in microangiopathic densities evident on computerized tomography scan with subsequent flap failure due to possible jeopardization of the flap microvasculature and perfusion. Following exclusion of common local and systemic factors that can cause vascular compromise, a debridement and salvage re-reconstruction procedure utilizing a contralateral free latissimus dorsi flap was performed. Reconstructive surgeons should be cautious when planning to utilize free abdominal-based flaps on the background of long-term therapeutic low molecular weight heparin administration in the abdomen and may possibly explore other alternative options of using non-abdominal free flaps from the reconstructive armamentarium within this unique context.