In traumatic amputation of digits, hands, or upper extremities, a decision whether to perform a microsurgical replantation depends on the condition of the stump and its amputated parts, the injury level, and the medical condition of the patient. Eastern and Western surgeons differ on indications for replantation. With recent advances in microsurgical techniques, virtually all levels of amputation—from the fingertip to the upper arm—can be considered candidates for replantation. The patient's medical condition and replantation timing are also determining factors impacting the complication rate and final functional outcomes. Emergent replantation is laborious for the plastic surgeon but should be performed with a sense of responsibility and pride in resurrecting the amputated tissue.
Specific controversies involving replantation of a very distal digit, single zone 2 digit, multiple digits, ring avulsion, trans-metacarpal level, and major limb replantation are discussed along with the issue of replantation timing.
Since these early developments, microsurgery has become an integral part of training plastic surgeons and hand surgeons in most major hospitals. Frequent emergency replantation surgery spontaneously evolves to elective microsurgical free tissue transfer. Even though an emergency replantation surgery as a resident or plastic surgeon can be a laborious job, it should be performed with a sense of responsibility and pride to resurrect amputated dead tissues. Experience in microanastomosis techniques for the replantation of very distal amputation can be developed for super microsurgery-related perforator-free flaps or lymphatic surgery. Also, emergency replantation of a major limb is sufficient to replace the clinical practice of allotransplantation of the extremities. With the refinement of microsurgical techniques and the development of microscope capabilities, the success rate of replantation has increased dramatically. Most plastic and hand surgeons have tried to perform replantation at all levels and with all types of injury patterns following the needs of the patients based on cultural background or specific conditions.
Toe-to-hand transfer is the last option for definitive reconstruction of the hand when digits have been lost as a result of traumatic amputations, congenital anomalies, or tumor ablation. Immediate toe-to-hand transfer for the treatment of acute hand injuries is defined as an emergency operation performed when replantation is impossible, delayed toe-to-hand transfer due to severe wound contamination or the patient's improper physical condition but performed as the first operation within two weeks following injury, or toe-to-hand transfer performed for patients transferred from other services within 72 hours following primary closure of an amputation or failed replantation.
Toe-to-hand transfer frequently causes patients significant psychological stress as it requires prolonged anesthesia, and the patient may see the operation as the loss of a toe rather than the saving of a finger. The operation is also stressful to surgeons as it demands a high level of microsurgical skill to yield aesthetically and functionally acceptable fingers. If the operation is performed for emergency treatment of acute hand injuries instead of delayed elective reconstruction, the indications for toe-to-hand transfer are very restricted.
In cases with severe crushing or avulsion amputation or where the amputated part has not been recovered, the surgeon should consider revision amputation or the use of various flaps to preserve finger length and ensure wound coverage. However, patients who strongly desire finger reconstruction and have the physical ability to sustain prolonged anesthesia may be candidates for immediate reconstruction via toe transfer. Preoperatively, it is imperative that the patient fully understands the potential risks of operative failure, as well as donor-site morbidity.
Immediate reconstruction of the hand provides many socioeconomic advantages, including lower medical costs and a shorter period of convalescence. Since the introduction of toe-to-hand transfer for hand reconstruction in 1969, this technique has been widely practiced at specialized hand surgery and microsurgery centers. Despite widespread use, the proper timing of toe-to-hand transfer in cases of acute injury has yet to be established. Wei et al. mentioned the concept of emergency toe transfer. We first published papers discussing immediate toe-to-hand transfers in 25 cases in 2004 and immediate partial big toe transfer for the reconstruction of composite defects of the distal thumb in 2006, in which replantation was impossible.
Simultaneous free flap reconstruction is a critical tool in replantation surgery. It provides an avascular conduit in cases with vessel defects and offers vascularized coverage for wounds that expose essential structures. Arterialized venous flaps can provide essential vessel conduits and soft tissue coverage in digit replantation. By restoring anatomic structures, this technique aids in ensuring the survival of the amputated digit or hand and allows faster wound healing.
Delayed free flap reconstruction primarily focuses on enhancing function. Incorporating functioning muscle, bone, joint, and nerve components effectively improves the range of motion in the hand and extremities, provides skeletal stability, and corrects deformities. Soft tissue flaps can address narrow web spaces, manage scar contractures, and rectify contour depressions.
On February 2, 2017, the surgical team of ten board-certified hand specialists of W Hospital in Korea successfully performed the nation's first-hand transplantation at Yeungnam University Medical Center.
W Hospital formed a memorandum of understanding with Daegu City and YUMC to comply with government regulations regarding hand transplantation. Campaigns were initiated in the media to increase public awareness and understanding. With the city's financial and legal support and the university's medical cooperation, a surgical team performed a left distal forearm hand transplantation from a brain-dead 48-year-old man to a 35-year-old left-handed man.
With this successful allotransplantation, the Korean Act on Organ Transplantation has now been amended to include hand transplantation. Korean national health insurance has also begun covering hand transplantation. Functional outcome at 36 months after the operation showed satisfactory progress in both motor and sensory functions. The disabilities of the arm, shoulder, and hand score were 23. The final Hand Transplantation Score was 90 points. Functional brain magnetic resonance imaging shows significant cortical reorganization of the corticospinal tract, and reinnervation of intrinsic muscle is observed.
Hand transplantation at the distal forearm shows satisfactory functional, aesthetical, and psychological outcomes. Legal and financial barriers against hand transplantation have long been the most burdensome. Despite this momentous success, there have been no other clinical applications of vascularized composite allotransplantation due to the limited acceptance by Korean doctors and people. Further public education campaigns for vascularized composite allotransplantation are needed to increase awareness and acceptance.