Sir: Hematologic disorders are rarely seen in patients with free flap reconstruction for head and neck defects. We report a patient with polycythemia vera who underwent successful free flap reconstruction. A 50-year-old man with known polycythemia vera presented with a T2N0M0 squamous cell carcinoma of the floor of the mouth. Bilateral selective neck dissections, a marginal mandibulectomy, and resection of floor of mouth were performed. A titanium plate was used to reinforce the remaining mandible. A left anteromedial thigh flap with a segment of the rectus femoris muscle was harvested because of the lack of perforators in the anterolateral thigh territories. The muscle was used to fill the floor-of-mouth defect and cover the anterior mandible. The skin portion of the flap resurfaced the intraoral mucosal defect. The recipient vessels were the lingual artery and common facial vein. The patient’s preoperative hemoglobin level was 18.5 g/dl and his hematocrit level was 52.7 percent. After phlebotomy preoperatively, his hemoglobin level dropped to 15.9 g/dl (Fig. 1). Intraoperatively, the patient was well hydrated and his hemoglobin level was monitored carefully. The patient lost approximately 400 ml of blood, and no blood transfusion was given intraoperatively. No intraoperative anticoagulation was given.Fig. 1.: The patient’s hemoglobin (Hb) and hematocrit (Hct) levels before surgery (Pre1 and Pre2), during surgery (OR), and after surgery up to postoperative day 5.The patient had an uneventful recovery. His postoperative hemoglobin level was monitored daily and remained relatively stable (Fig. 1). Postoperatively, the patient received a daily baby aspirin, with no other anticoagulatory therapy. No thrombotic events occurred, and the flap survived in its entirety. He was discharged on postoperative day 6 and started on an oral diet following a negative modified barium swallow study on postoperative day 8. At 1 year, he showed excellent oral function, with a regular diet and normal speech, and near-normal appearance of the face and neck. A follow-up intraoral photograph is shown in Figure 2.Fig. 2.: A follow-up photograph at 6 weeks shows a well-healed anteromedial thigh flap for floor-of-mouth reconstruction, without excessive bulk.Free flap reconstruction in patients with polycythemia vera therefore seems a viable option, provided that necessary precautions are taken. With increased hematocrit levels and blood viscosity in polycythemia vera, microvascular thrombotic events exist.1 Thrombotic events are present in 20 to 50 percent of patients with polycythemia vera associated with essential thrombocythemia.2 Medical management for polycythemia vera involves primarily cytoreduction with phlebotomy. Interferon alfa, hydroxyurea, and low-dose aspirin are other treatment options.3 Low-dose aspirin helps prevent microvascular thrombosis. The “safe” hemoglobin/hematocrit level for microvascular surgery is unknown. However, it is imperative that hemoglobin and hematocrit levels be reduced to normal range perioperatively, using phlebotomy and/or myelosuppressive agents.4 With an estimated 400 ml of intraoperative blood loss and hemodilution in the perioperative period, the patient’s hemoglobin level gradually dropped to 10 g/dl on postoperative day 4 before it started to climb. This gave us a “safe” time period for the free flap to survive. The need for intraoperative anticoagulation is somewhat controversial. The senior author does not routinely give anticoagulation agents during the perioperative period. Because this patient’s hemoglobin level was within the normal range, no anticoagulation was given intraoperatively. Postoperatively, aspirin therapy is practical for patients with polycythemia vera, even if, as in the present case, there is no associated essential thrombocythemia. Samuel J. Lin, M.D. Division of Plastic Surgery Beth Israel Deaconess Medical Center Boston, Mass. Peirong Yu, M.D. Department of Plastic Surgery University of Texas M. D. Anderson Cancer Center Houston, Texas