Anticoagulation

Success in microsurgery requires intact circulation through microvascular blood vessel anastomoses.  Although the clotting mechanism prevents injured tissues from bleeding, it can be disruptive to a microvascular repair - inhibiting blood flow and promoting flap failure.  Many factors are involved in the development of clots and include:

• Vessel injury from trauma

• Hematoma and external pressure on vessels

• Tension or kinking of vessels

• Microsuture and microsuture penetration injury

The role of routine post-operative anticoagulation in microsurgery has been debated for several years but has not determined absolutely.  Anti-coagulation can increase the chance of hematoma both at the flap donor and recipient sites, and even in rare circumstances, may cause an allergic reaction.  However,  familiarity and personal experience play a large role in post-operative anti-coagulation regimens from surgeon to surgeon.  Anti-coagulation is felt by some to reduce the chance of post-operative clotting at the anastomosis site.  Most commonly,  aspirin and dextran are used.  Intravenous heparin is generally utilized when difficulty is encountered, such as post-operative thrombosis.  The most commonly used pharmacologic agents are:

1. Aspirin

2. Dextran

3. Heparin

4. Leeches

Each is used to block a specific site in the clotting cascade to inhibit thrombosis.  Leeches also act mechanically to remove stagnant blood and bring in new oxygenated flow.