Low molecular weight heparin for prevention of microvascular occlusion in digital replantation.

Abstract

Microvascular surgery refers to any surgery involving small sized blood vessels that is performed under the operating microscope, allowing the repair of arteries and veins of the digits. These are typically 1 mm to 2 mm in diameter. Replantation is the reattachment of a completely detached body part, with fingers and thumbs being the most commonly replanted body parts. This is often referred to as digital replantation. In principle, digital replantation involves not only restoring the blood flow through the arteries and veins but also restoring the bony skeleton of the toes, fingers or thumbs, along with repairing the tendons and nerves as indicated. Occlusion of one or more of the repaired vessels due to the formation of a clot (thrombus) within the blood vessel results in failure of the replantation. Anticoagulant medications are used to reduce clotting, and they could potentially prevent such a complication. Anticoagulants such as unfractionated heparin (UFH) have therefore been used to prevent clot formation after digital replantation. It is unclear if low molecular weight heparin (LMWH) has similar benefit. This systematic review identified only two randomised controlled trials comparing UFH with LMWH, with a total of 114 patients. No studies were identified that compared LMWH with placebo, no treatment or other anticoagulants. The limited data from the two trials showed no difference between LMWH and UFH in the success rate for digital replantation but there were less frequent anticoagulation-related adverse events (such as bleeding) with LMWH. The available evidence is insufficient to make a firm conclusion.