Perioperative management of Evans Syndrome for free tissue transfer: Case report and recommendations

Evans syndrome (ES) is a rare autoimmune disorder characterized by autoimmune hemolytic anemia and immune thrombocytopenic purpura, conferring an increased risk of postoperative bleeding, thrombosis, and infection. Limited guidance for perioperative management is available for patients with ES undergoing free flap reconstruction.

A 21-year-old female presented with a six-month history of progressive forearm pain, a palpable tender mass in the right volar forearm, paresthesias in the ulnar nerve distribution, and limited forearm rotation from neutral to 30 degrees supination. Imaging revealed an expansile lytic lesion in the midshaft of the ulna, and biopsy diagnosed an aneurysmal bone cyst (ABC). Medical history was significant for ES, stable on daily sirolimus and hydroxychloroquine with weekly intravenous immunoglobulin (IVIG) infusions. Preoperative labs were within normal limits. She underwent wide local excision of the ABC, resulting in an 8.5 cm bony defect within the midshaft of the ulna. A vascularized free fibula flap was performed to reconstruct the ulna. Sirolimus and hydroxychloroquine were held for one week pre- and post-operatively and IVIG continued peri‑operatively. While hospitalized, she received Aspirin 325 mg and Lovenox 40 mg daily for deep vein thrombosis prophylaxis. Daily labs confirmed stable blood counts. At 4 months post-operatively, CT scans confirmed bony union of the proximal and distal osteotomy. She regained near full supination and pronation range of motion, and all her incisions were well-healed.

In patients with ES undergoing free tissue transfer, perioperative management of immunosuppression and anticoagulation must balance the risks of bleeding, anastomotic thrombosis, and wound healing complications. Our patient was safely treated with prophylactic anticoagulation while hospitalized and immunosuppressive medications were held one week pre- and post-operatively. Overall, we report successful vascularized free tissue transfer in a patient with ES on chronic sirolimus without incidence of hematoma, thrombosis, or infection.