Fingertip injury is one of the most common hand injuries, and numerous techniques have been attempted to treat it. Healing by primary closure and revision amputation can be the most straightforward method, but they can cause hook-nail deformity or neuroma formation at the stump. Skin grafts are another option, but only for defects without bone or tendon exposure [9
]. Various local flaps have been developed to reconstruct fingertips including V-Y flaps, cross-finger flaps, thenar flaps [10
], and island flaps [11
]. However, postoperative scar contracture or flexion deformity remained as sequelae, and sometimes those flaps are not possible for treating a tip defect such as a transversely amputated stump or pure pulp defect extended to the middle phalanx. Because advances in microsurgery allow options for microsurgical restoration of distal digits, free toe tissue transfer has become the superior choice over conventional techniques in esthetics and function [12
Adequate venous outflow is one of the most important factors for successful free toe tissue transfer including distal digital reconstruction [3
]. Of course it is the safest option if at least one successfully anastomosed vein is present. However, previous studies have provided convincing evidence that amputated fingertips can be salvaged successfully using only arterial anastomosis with simple surgical or nonsurgical methods of venous drainage [13
]. We adopted this method for free toe tissue transfer for fingertip reconstruction. All 5 of our cases of free toe tissue transfer of artery-only anastomosis survived without significant complications. Periodic pin-pricking did not require blood transfusion or prolonged hospitalization. We believe that this consistent result comes from the wide contact surface between the donor flap and recipient site compared to the flap volume. A wide contact surface enhances early revascularization of a replanted flap, and for that reason total flap survival was achieved.
In some ways our procedure could be considered a form of free composite graft. However, the donor tissue in a composite graft is totally devitalized because there is no blood flow initially. This is the biggest and the most important difference between a composite graft and our procedure. Although survival of a free tissue transfer is critically dependent on the patency of arterial and venous anastomosis in the early phase, the vascular stability of the transferred flap is eventually affected by neovascularization between the donor and recipient tissue. Therefore, vascular development in the contact area is another important factor for flap survival. If the donor tissue has its own vascular supply, this process can be facilitated. Even considering the arterial flow alone, the donor tissue had a vascular component in our cases, and we believe this promoted neovascularization on the contact surface. Furthermore, a harvested donor flap was less limited in size and dimension than a composite graft due to this reliable arterial supply.
Furthermore, toe tissue transfer with the arterial-anastomosis-only technique has some advantages over the conventional anastomosis of both arteries and veins. There is no need for an additional dissection or anastomosis for the veins; thus, simplification of the surgical procedure can be achieved, and the mean operation time would be shortened.
This also helps to reduce the internal damage of a harvested flap. Sometimes a transferred flap requires a smaller and thinner volume of soft tissue for an esthetically pleasing result. As the concerns about supermicrosurgery increase and the techniques continue to be developed, surgical attempts can be made for difficult venous anastomosis in these small flaps. However, dissection for finding venous outflow may cause severe internal injuries. In our method, dissection procedures were simplified to lower the risk of flap damage. Additionally, flaps can have some variations in design because there is no obligation to include veins.
The patient satisfaction results also verified the cosmetically acceptable outcomes. A fingertip is not only functional but also esthetically important for a hand. Because there was no need of additional incisions for the recipient veins, scars were minimized and the patients were satisfied with the results.
There are some disadvantages of arterial-only anastomosis in free toe pulp transfer. Close and frequent observation is needed for early recognition of flap congestion and periodic pin-pricking. It is also difficult to verify the adequate timing and bleeding amount due to the lack of a decongestion guideline. The limitation of this study is related with determining the adequate flap size and volume. We empirically assumed the suitable flap size for artery-only anastomosis, but further studies should be conducted for a general consensus on a maximum flap volume amount to transfer without venous anastomosis.