Purpose: Therapeutic anticoagulation is often employed to salvage a free flap following anastomotic repair of vascular thromboses, and is frequently associated with undesirable side effects. Regional heparinization might provide the means to selectively treat the anastamotic site without systemic anticoagulation. The current study reviews our initial experience with regional heparinization in the post-operative management of free flap salvage operations. Methods and Materials: We performed a retrospective review of eight consecutive patients over a two-year period in which thrombosis complicated elective free flap reconstruction. Heparin was infused continuously at 100 IU units per hour via an epidural catheter intubated into a branch vessel of the vascular axis located proximal to the arterial or venous anastomosis, depending upon the etiology of the thrombosis. Prothrombin (PT) and partial thomboplastin times (PTT) were measured intraoperatively and daily throughout the study period. Results: There were 6 females and 2 males. Average age was 52 years (range: 42-64). Study cases included: Breast reconstruction (N=4); radionecrosis/osteoradionecrosis (N=2); lower extremity salvage for vascular disease (N=1); delayed reconstruction of a facial shotgun blast (N=1). Vascular compromise was due to venous thrombosis 2 cases, and arterial thrombosis in 6 cases. Vein grafts were employed in 4 cases, (2A, 1V, 1A&V) either initially (2 pts) or during re-exploration (2 pts). Regional heparinization was instituted an average of 1.7 days after free flap surgery (range: 1-4) and continued for an average of 6.5 days (range: 2-11). Regional heparinization was not associated with a prolongation of systemic coagulation parameters. Complications included: hematoma requiring operative exploration (N=4), erosion of the infusion catheter through the artery (N=2), catheter clotted at 10 days post operatively (N=1). Six of the 8 flaps treated were salvaged (75%). Fat necrosis occurred in 3 of the 4 flaps employed for breast reconstruction, and delayed wound healing was noted in 2 flaps. Conclusions: This retrospective study demonstrates that regional heparinization can be successfully employed in free flap salvage of anastomotic thrombosis, but the treatment is not without shortcomings. Despite normal systemic coagulation parameters, the high rate of wound hematoma suggests that the dosage of heparin infused may be excessive. Additionally, the 2 cases of catheter induced vessel erosion might have been avoided by use of a more pliable anticoagulant delivery system. This experience highlights the risks of regional heparinization and underscores the need for further modification and objective inquiry prior to the endorsement of this technique.