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.