Microsurgery is a general term for surgery requiring an operating microscope. The most obvious developments have been procedures developed to allow anastomosis of successively smaller blood vessels and nerves (typically 1 mm in diameter) which have allowed transfer of tissue from one part of the body to another (free tissue transfer) and re-attachment of severed parts. (replantation)
Free tissue transfer is a surgical reconstructive procedure using microsurgery. A region of “donor” tissue is selected that can be isolated on a feeding artery and vein; this tissue is usually a composite of several tissue types (e.g., skin, muscle, fat, bone). Common donor regions include the rectus abdominis muscle, latissimus dorsi muscle, fibula, radial forearm bone and skin, and lateral arm skin. The composite tissue is transferred (moved as a free flap of tissue) to the region on the patient requiring reconstruction (e.g., mandible after oral cancer resection, breast after cancer resection, traumatic tissue loss, congenital tissue absence). The vessels that supply the free flap are anastomosed with microsurgery to matching vessels (artery and vein) in the reconstructive site.
Replantation is the reattachment of a completely detached body part. Fingers and thumbs are the most common but the ear, scalp, nose, face, arm and penis have all been replanted. Generally replantation involves restoring blood flow through arteries and veins, restoring the bony skeleton and connecting tendons and nerves as required.. However, as more experience was gained in this field, surgeons specializing in replantation began to understand that survival of the amputated piece was not enough to ensure success of the replant. In this way, functional demands of the amputated specimen became paramount in guiding which amputated pieces should and should not be replanted. Additional concerns about the patients ability to tolerate the long rehabilitation process that is necessary after replantation both on physical and psychological levels also became important.