Minimally invasive late free flap salvage: indications, efficacy and implications for reconstructive microsurgeons.

One of the most common causes of free flap compromise is microvascular thrombosis. Acland et al describe two described zones of injury: zone 1 the anastomotic site and zone 2 downstream. Factors contributing to zone 1 thromboses include anastomotic irregularities, suture material and platelet adhesion. This often presents in the early postoperative period. Zone 2 however, is less well described and is associated with diffuse microvascular ischaemia. Often, these cases are associated with the use of vein grafts in a delayed reconstructive setting, and present relatively late in their postoperative follow up. There are sporadic reports in the literature of late free flap salvage managed via anastomotic revision, thrombectomy, and the use of thrombolytic agents. We describe the successful use of catheter-directed endovascular urokinase in revascularizing two free flaps which presented in the late postoperative setting. This report demonstrates the safety and efficacy of this technique in free flap salvage. Although late presentation of free flap compromise is uncommon, this report reiterates the importance of long-term surveillance of these patients. It should be remembered, however, that long-term anticoagulation is required, and may not be feasible in certain patient populations. Given that free tissue transfer is often employed when other forms of reconstruction are unavailable, endovascular thrombolysis is a valuable tool for the reconstructive microsurgeon, and its role in early free flap salvage warrants exploration.