Free tissue transfer

The development of high-quality binocular operating micro­scopes, swaged rnicrosutures and rnicrosurgical instrumenta­tion has, along with advances in the understanding of flap vascular anatomy, enabled reliable free flap surgery. The first successful microsurgical free tissue transfer was a toe transfer to reconstruct the thumb. Microsurgical transfer of toes or portions of toes to reconstruct hand defects has now become a routine procedure in hand surgery. Most of the other types of flaps described above can be reliably transferred micro-surgically. Free tissue transfer allows the design of customised composite flaps without the constraints of loco-regional flap transfers. Successful free flap transfer requires careful planning of the most appropriate flap to reconstruct the defect. Of prime importance is selection of the recipient vascular axis; the operation is designed to ensure the microvascular anastomosis is done to the largest available vessels, thus maxirnrsing blood flow Other factors such as keeping the patient warm, ensuring the patient has a good circulating volume, providing perioperative and postoperative analgesia where possible with regional anaesthesia are also important. Technical issues such as ensuring atraumatic dissection and vessel handling, avoiding tension and kinking of vascular pedicles and gentle irrigation of the vessel lumen with heparinised solutions are essential.

Experienced teams can expect success rates in excess of 95 per cent for most free tissue transfers, placing it amongst the most reliable of techniques. Flap failure is best detected by regular observation of the flap by experienced individuals. If there is any doubt the patient must be rapidly returned to theatre and the microvascular anastomoses inspected. Prompt re-exploration will usually salvage a failing flap.