High-energy injuries are associated with loss of muscle, nerve, blood vessels, and bone, making it difficult to treat the wounds left after primary debridement. With the development of surgical techniques, especially microsurgery, many limbs have been preserved instead of being amputated. Therefore, the focus has shifted to how to improve the appearance and function of the preserved limbs.
For severely complex upper limb wounds, selecting the tissue with adequate blood supply to cover the wound is most important(8, 9). In our study, three kinds of flap were used to reconstruct upper limbs. The lateral arm flap could only be transplanted to repair smaller defects in the forearm or hand because of tissue limitations. The latissimus dorsi musculocutaneous flap provides sufficient tissue to repair the extensive soft tissue defects; however, patients later complained not only of postoperative bloated appearance, but they also complained of the heavier limb with limited flexibility of the affected limbs. The anterolateral thigh flap has been called a “universal flap”, designed to include several tissue components, has been widely used to repair soft tissue defects(10). We used the anterolateral thigh flap without fascia lata to repair the wounds without obvious bone exposure and infection, reducing damage to the donor site, while simultaneously improving the appearance of both donor and recipient site. For the patients with wide defect areas, lobulated flaps can be designed to change the width to length, ensuring one-stage closure of the donor area. This avoids several complications, including scarring, adhesions, and contour defects caused by skin grafting. If the damage involved the trunk vessels in the recipient area, flow-through flaps are the best choice because they provide simultaneous arterial reconstruction and soft-tissue coverage(11). The latissimus dorsi flap is most suitable for patients who needed restoration of elbow function, because this flap provides good dynamic muscles for the flexor and extensor muscle group (12).
Because of inter-individual variations in perforator anatomy, preoperative vascular mapping was introduced to help identify the dominant perforator. In our study, we performed computed tomography angiography (CTA) or color doppler sonography (CDS) to map perforators before applying an ALT perforator flap to repair soft tissue defects. According to our previous study(13), CTA had a higher sensitivity than CDS for detecting vessels. Therefore, we typically used CTA first to create clear 3D images of the vessels and surrounding structures, as well as to mark the skin. If the patient was allergic to iodine had renal insufficiency, they would undergo CDS to determine the position, path, caliber, and quality of the perforator vessels, and to mark the skin. We depended on the results of CTA and CDS to identify the best perforators to design the ALT perforator flaps. If the perforators are located precisely, the surgeon can identify the path of the perforator in the surrounding area and minimize incisions of the muscle and deep fascia during the operation, thereby reducing complications at the donor site. Furthermore, this makes the surgeon’s task easier.
There has been no consensus regarding the most appropriate time to cover upper limb wounds using skin flap transplantation. As early as 1986, early covering of the wound was suggested by Godina(4); it was suggested that if flap transplantation should be carried out within 72 hours to close the wound, the necrosis rate of the flap would be 0.75%, greatly reducing the postoperative infection rate and hospital stays. However, since 1990, several studies have shown that secondary tissue transplantation can achieve better effects. In particular, there has been application of the negative-pressure wound therapy technique(14). The benefits of negative-pressure wound therapy include increased perfusion, fresh granulation tissue, promotion of angiogenesis, wound area reduction, cellular proliferation, decreased bacterial contamination, and reduction of the inhibitory effects of wound exudates(12, 15). According to Derderian(7), covering the wound using tissue transplantation on the 6th and 21st day after injury has obvious advantages over other times; flap necrosis rates, postoperative infection rates, incidences of osteomyelitis and nonunion were lower and the one-stage operation time was shortened, making patients more tolerant of the secondary operations. Delayed closure of the wound prevents proliferation of anaerobic bacteria while allowing sufficient time to identify the tissue that survives during primary debridement, avoiding more radical scavenging of surviving tissue, or leaving possible necrotic tissue resulting in late wound deferred. However, the later the wound is closed, the worse the function of the affected limb, resulting in heavier psychological and economic burdens. The reasons for this can be summarized as follows: (1) Wound infections correlate with longer exposure times. Despite the fact that the VSD negative pressure sealing technique keeps the wound closed, it can only guarantee effective sealing for 3 days; (2) Long-term inflammatory stimulation causes edema and adhesion of surrounding tissues, leading to stiffness and tissue organization; (3) Long-term exposure of bony tissue can easily lead to nonunion, necrosis and bone infections, increasing the difficulty of bone tissue repair at the later stages; (4) Long-term bed-rest leads to disuse atrophy of muscle and late limb dysfunction; (5) Inflammation stimulates peripheral blood vessels and nerves, causing edema and adhesions with surrounding tissue, resulting in increased graft necrosis rates of the late flap.
Of the 35 patients we treated, individualized treatments were developed according to the patient's condition and injury, as well as their condition on admission. In the subacute stage, the wound was closed by tissue transplantation. Therefore, we believe that subacute wound closure, if possible within 5–30 days after emergency surgery, remains a better choice. Emergency flap transplantation is not recommended unless there are important vessels and nerves that must be repaired. Mundi(16) suggested that primary wound closure is best for fractures with less severe soft-tissue injuries, to allow for tension-free closure. For those injuries requiring delayed closure, definitive coverage should not be delayed beyond seven days, even in the setting of negative-pressure wound therapy. We believe that, for patients with severe open fracture of upper limb, phased treatment not only effectively reduces the infection rate, but also allows more choices of skin flap in the subacute stage. In our series, no patient underwent amputation. The two lost partial flaps were an anterolateral thigh flap and a latissimus dorsi flap, both because of deficient blood supply. (5.71%). Traumatized wound infection occurred in three patients (8.57%). Two of them resulted from progressive muscle and soft-tissue necrosis of the wound; however, the patient with superficial infection healed after five change dressings at the bedside. Zoran et al.(17), reported that the main reason for infection was most often nosocomial infection, in agreement with our series.
Patients with severe open fractures of the upper extremity often suffer severe trauma, requiring frequent operations and long periods of treatment. If there is difficulty in performing free flap transplantation, flap necrosis may lead to amputation. Therefore, it is very important to evaluate and select blood vessels in the recipient area before surgery. First, we should evaluate the patient's condition comprehensively according to the location of the wound and the degree of injury. Prior to surgery, CTA or B-ultrasound should be performed to verify vascular patency and diameter. During surgery, the quality of blood vessels should be accurately evaluated to avoid scarring vessels. Furthermore, heparin should be used to flush the vessels repeatedly during the operation to judge its quality and patency.