Severe traumatic injuries that lead to large soft tissue defects and/or vascular impairment have become a challenging problem for reconstructive surgeons. Microsurgical techniques such as flap transfer causes tissue loss in extremities in patients but is a reliable option for assessing healthy free tissues and recipient vessels.1,2 However, the major trauma of extremities, especially during severe injury, more often involves bones, vascular, and their soft tissue coverage defects. Traditional flap could not solve the problem in these cases, as the complex injuries not only involves closure of the defects but also requires restoration of complete hemoperfusion of the distal artery and functioning of the limb.
Flow-through flaps have been widely used in reconstructive surgery since 1983.3 It is advantageous because of sufficient perfusion of it into the distal tissue, as free flap with vascular pedicle is anastomosed to both proximal and distal ends.4 The flap cover also plays an important role in reconstruction when deep structures (such as tendons, nerve, and/or bone) are exposed. Flaps from free anterolateral thigh (ALT) have been reported to successfully bridge the vascular gaps of up to 20 cm and provide soft tissue coverage of up to 30 cm in length and 15 cm in width.5 We herein presented the use of flow-through free ALT flap for reconstruction of severe limb injuries, which include bone, vascular, and large soft tissue defects.
PATIENTS AND METHODS
This retrospective observational study was approved by the ethics committee of the Air Force Military Medical University. Four patients (2 male and 2 female subjects), with an average age of 26 (9–39) years, were included. The characteristics of these patients were analyzed and presented in Table 1. All patients included have experienced high-energy trauma. These injuries referred to upper and lower limbs, including bone, soft tissue, nerves, and arterial segments. Two patients had large soft tissue defects in the lower limb and underwent repair by double flow-through ALT flaps. The sizes of damaged soft tissues of the remaining 2 patients were 14 × 10 cm2 and 21 × 13 cm2, respectively. Three patients had bone fractures, and one of them experienced bone shortening during operation. Arterial injury was observed in 2 patients and the lengths of defects were 5 and 12 cm, respectively.
The patient was placed in supine position after undergoing general anesthesia. All devitalized tissues have been removed thoroughly after aggressive debridement. K-wires were used for fixing phalanges and small joints in the left hand of a patient. External fixator along with lag screw was used for fixing tibial fractures in the other 2 cases. Emergency “orthoplastic” surgery (do bone, soft tissue, and other vessel/nerve defects reconstruction in the same stage) was performed in 2 cases and in the remaining 2 patients traditional orthopedic treatment (reconstruction completed by more than one stage) was performed. The defect associated with ulnar artery and median nerve in one case was repaired by small saphenous vein and sural nerve transplantation. The soft tissue defects in all cases were reconstructed by flow-through ALT flaps. Anterolateral thigh flaps with vessel were harvested from contralateral thigh in 2 patients with upper limb and hand injuries. The lower limb in the other 2 patients was repaired by double flow-through ALT flaps and skin grafting. Microsurgical end-to-end anastomosis was performed between the proximal/distal peroneal arteries of the flap and the proximal/distal arteries of the recipient site, respectively, and similarly was done for anastomosis of the veins. The flaps were sutured loosely in situ and then carefully manage the blood supply, anti-infection, anticoagulant, and antispasmodic methods. Radiography was performed after 1 week of surgery. The duration of follow-up period was more than 18 months.
The flow-through ALT flaps have survived in all patients uneventfully. The blood supply and the arterial pulse of distal limbs in these cases appeared normal after operation. After removing the stitches at 2 weeks, patients were followed up every 6 weeks. K-wires and external fixation were removed after 6 months of operation. At week 12 after operation, the patient was permitted for partial weight bearing. Functional recovery and movements were achieved after 9 to 10 months. All the flaps have survived successfully without vascular crisis or infection. All incision wounds were in primary healing stage and showed no severe complications. The flaps showed better appearance, color, texture, and satisfactory sensation. All patients were satisfied with the functional recovery of their injured limbs.
A 19-year-old man was referred to our hospital with severe trauma in the left forearm because of a rolling injury after 6 hours of the initial accident. The volar defect area in the left forearm of this patient was 1014 cm2. The muscles and tendons (including brachioradialis, flexor carpi radialis, flexor carpi ulnaris, palmaris longus, superficial flexor of the index finger, middle finger, ring finger, and little finger), ulnar nerve, radial nerve and median nerve, radial artery and vein, as well as ulnar artery and vein were severely damaged (including defects and contamination; Fig. 1A). Radiographic examination showed no fracture of the left forearm and hand (Figs. 1B, C). After aggressive debridement of the contaminated tissue, the left ALT flap (10 × 14 cm) used for covering was measured (Fig. 1D). However, because of vascular variation of the left ALT flap, the right ALT flap was chosen (Figs. 1E, F). The rupture of tendons was reconstructed by anastomosis and weaving. The defect of ulnar artery and median nerve was repaired by left small saphenous vein and left sural nerve transplantation, respectively. External fixator was used for wrist stabilization. The pedicled ALT flap was end-to-end anastomosed onto the proximal radial artery in the proximal pedicle and anastomosed onto the distal radial artery in distal pedicle. The vein of ALT flap was end-to-end anastomosed onto the radial vein in the same manner by using a 10-0 nylon suture (Fig. 1G). Angiography showed complete patency of the radial artery and ulnar artery (Fig. 1H). The patient was requested to undergo functional training after surgery (showed in supplementary data, http://links.lww.com/SAP/A484, http://links.lww.com/SAP/A485, http://links.lww.com/SAP/A486, http://links.lww.com/SAP/A487, http://links.lww.com/SAP/A488, http://links.lww.com/SAP/A489, http://links.lww.com/SAP/A490, http://links.lww.com/SAP/A491). However, as the muscles and tendons were severely damaged in this patient, the strength of the muscles and tendons showed slow improvement and the patient was permitted to undergo partial weight bearing (such as carrying heavy things) until 12 weeks postoperatively. External fixation was removed at 6 months postoperation. Satisfactory functional recovery was achieved at 9 months postoperation (Figs. 1I, J).
A 39-year-old woman was transferred to our department with severe trauma of right leg because of a bruise injury after 39 hours of initial accident. Large defects of soft tissues and serious contusion were observed in her right leg (Fig. 2A). All the devitalized tissue was removed by thorough debridement (Fig. 2B). Composite defects were observed and the reserved tissues included the right anterior tibial artery and vein, posterior tibial artery and vein, tibial nerve, superficial peroneal nerve, extensor digitorum longus, peroneus, tibialis posterior, Achilles tendon, partial gastrocnemius, and flexor digitorum longus. Other tissues of right leg were all removed (Fig. 2C). Radiographic examination showed fractures of right tibial and fibular bones (Fig. 2D). Bone shortening was done for restoring the length of the tibia. External fixator along with lag screw was used for fixing the tibial fracture (Figs. 2E–G). The design of double flow-through ALT flaps for repairing the right leg was shown in Figure 3. Both sides of the ALT flaps were harvested. A microsurgical end-to-end anastomosis was performed between proximal artery of the pedicled ALT flap and proximal anterior tibial artery by using a 10-0 nylon suture. Another pedicled ALT flap was end-to-end anastomosed onto the distal artery and anastomosed onto the distal anterior tibial artery in the distal pedicle as illustrated in Figure 3. The vein of ALT flap was anastomosed in the similar manner. These 2 flaps covered the tibia, fibular, and deep tissues in a satisfactory manner (Figs. 3A–F). Skin grafting was used to cover the exposed muscles in the right leg after 2 weeks. Tibial osteotomy lengthening operation was conducted at 8 months of postoperation, and the fixation was replaced by unilateral external fixation (Figs. 3G–J). The flaps and the grafted skin survived uneventfully with no perioperative complications and achieved satisfactory functional recovery and ambulation at 9 months of postoperation (Figs. 3K–N).
Free-flap techniques have been widely used for complex traumatic injuries to overcome recipient composite defects. However, patients with severe soft tissue and vessel defects in the distal limb are still facing challenges for reconstruction by traditional flap methods. This retrospective study demonstrated that flow-through free ALT flap was a reliable way for reconstruction of large soft tissues and main arterial segmental defects. All the flaps survived successfully without vascular crisis or infection. Satisfactory functional recovery and movements were achieved.
The failure rate of free tissue transfer in the lower extremity in some cases is more than 10%.6–8 Besides, there are some other complications associated with lower extremity free flaps, such as the risks of venous and arterial thrombosis, venous congestion, and tissue edema because of limited venous outflow, which increase the risk of flap failure.9,10
On the other side, arterial vascular grafts have the advantages in the reconstruction of arterial defects based on high long-term patency rates.11–15 Since 1983, numerous flow-through flaps have been reported.3,16–19 Severe limb injury might lead to fractures, large area of soft tissue losses, and segmental defects on both sides of the arteries, and it not only requires wound covering but also requires blood supply to the distal limb. Effective approaches usually included a flap combined with a vein graft20 or a flow-through flap.21,22 The former method requires additional vein graft operation, thus increasing the risk of infection and influencing the blood circulation from the donor end. Moreover, this method might be impossible if the donor vein is injured. Flow-through flap provides opportunity to revascularize the recipient ischemic site rather than just covering the soft tissue defect. A flow-through flap, which requires more microvascular anastomoses, seems to be more complex than simple free flaps.18 The traditional reconstruction by simple free flaps involves 2 stages: revascularization by vascular graft and flap coverage of the defect. This faces a second surgery, prolonging the operation time, increasing the complications, etc. These deficiencies are exactly avoided by flow-through flap. Besides, researches have shown that usage of long vein grafts might reverse the flow within the vein grafts and arteries, causing turbulent flow, stasis, and thrombosis.23 Artificial blood vessel has some advantages but has significantly lower patency rate, high limb salvage rate, and risk of infectious complications, limiting its application.24,25 Therefore, in complex extremity injuries, flow-through flap is regarded as an efficient alternative for revascularization and coverage.
Flow-through flap plays a role of “vessel bridge” by providing vascular pedicle for reconstruction of the main artery. The cutaneous branch or muscular branch of the flap pedicle can repair the wound by its affiliated fascia and muscle. Therefore, it is considered to be an ideal method for restoring arterial and soft tissue defects, thus achieving the goal of rebuilding the circulation and coverage simultaneous. This raises the question that the flow-through flap pedicle is long, wide in diameter, and with hypervascularity of cutaneous branch.
The significant advantage of this flow-through flap is that it provides blood supply without sacrificing the main vessels. Thus, the primary indication of flow-through flap is that the injured limb exists only by one main blood vessel. Flow-through flap can also be used for repairing an artery in which both the main blood vessels were injured. This method also eliminates complication such as autonomical disturbances.
As for these advantages, flow-through flaps can be used for numerous purposes of limb reconstruction. More specifically, the flow-through flap had been successfully chosen for reconstruction in electrical burns of the severely damaged upper extremity,26 ischemic extremities,27 posttraumatic defects of the foot,28 and extremity injuries with soft tissue and long vascular gap29 because of its capacity of providing soft tissue coverage and arterial repairing simultaneously. Other reports30–35 showed that flow-through flaps supplied from multiple sources can satisfy varied requirements of complex soft tissue defects and major arterial damage.
Longer vascular pedicle, which does not need sacrifice the main artery and can be harvest through the supine position, made ALT flap superior to other types of flow-through flaps.36 Tang et al37 showed their application of flow-through chimeric ALT perforator flap for complex defects of the extremities. The results indicated that this kind of chimeric ALT flow-through flap is an effective method for complex injuries in the limbs with dead space.
Chen et al38 have described their uses with regard to flow-through flap, pointing out that there is no vessel crisis occurred in their cases. However, a slight postoperative edema in flow-through flaps was observed. In our cases, functional recovery and movements were achieved without any severe complications, and also no postoperative edema was observed. All patients were satisfied with good functional recovery of their injured limbs.
The highlight of our study is that one of these cases (case 2) presents a typical concept of “orthoplastic,” which refers to a well-combined approach to open fractures. The combined “orthoplastic” treatment aims to repair fractures and soft tissue in one stage and has been recommended by the publication of standards of care (British Orthopedic Association, British Association of Plastic Reconstructive and Aesthetic Surgery).39 More than that, the debridement, fix, flap, and vascular anastomosis were accomplished in one stage in case 2. Based on thorough and satisfactory debridement, the timing of flap coverage in case 1 and case 2 was in primary operation. This operation made 2 patients achieved very satisfying limb functional recovery without any complication.
Our study indicated the flow-through free ALT flap was an effective and reliable option for the reconstruction of large soft tissue and main artery segmental defects. It provides a well-vascularized viable tissue cover for exposed deep structures (tendons, nerve, and/or bone). It avoids further infection after first debridement. This one-stage management has been proved more effectively and safely in severe open fracture managements.
1. Ozkan O, Ozkan O, Bektas G, et al. Experiences with the flow-through radial forearm flap as a bridge in lower extremity reconstruction. Microsurgery
2. Ozalp T, Masquelet AC, Begue TC. Septocutaneous perforators of the peroneal artery relative to the fibula: anatomical basis of the use of pedicled fasciocutaneous flap. Surg Radiol Anat
3. Soutar DS, Scheker LR, Tanner NS, et al. The radial forearm flap: a versatile method for intra-oral reconstruction. Br J Plast Surg
4. Zheng DW, Li ZC, Shi RJ, et al. Use of giant-sized flow-through venous flap for simultaneous reconstruction of dual or multiple major arteries in salvage therapy for complex upper limb traumatic injury. Injury
5. Haddock MC, Creagh T, Sivarajan V. Double-free, flow-through flap reconstruction for complex scalp defects: a case report. Microsurgery
6. Sakurai H, Yamaki T, Takeuchi M, et al. Hemodynamic alterations in the transferred tissue to lower extremities. Microsurgery
7. Fischer JP, Wink JD, Nelson JA, et al. A retrospective review of outcomes and flap selection in free tissue transfers for complex lower extremity reconstruction. J Reconstr Microsurg
8. Ridgway EB, Kutz RH, Cooper JS, et al. New insight into an old paradigm: wrapping and dangling with lower-extremity free flaps. J Reconstr Microsurg
9. Fujiki M, Miyamoto S, Sakuraba M. Flow-through anastomosis for both the artery and vein in leg free flap transfer. Microsurgery
10. Chow SP, Chen DZ, Gu YD. The significance of venous drainage in free flap transfer. Plast Reconstr Surg
11. Collins P, Webb CM, Chong CF, et al. Radial artery versus saphenous vein patency randomized trial: five-year angiographic follow-up. Circulation
12. Webb CM, Moat NE, Chong CF, et al. Vascular reactivity and flow characteristics of radial artery and long saphenous vein coronary bypass grafts: a 5-year follow-up. Circulation
13. Godina M. Arterial autografts in microvascular surgery. Plast Reconstr Surg
14. Masden DL, Seruya M, Higgins JP. A systematic review of the outcomes of distal upper extremity bypass surgery with arterial and venous conduits. J Hand Surg Am
15. Masden DL, McClinton MA. Arterial conduits for distal upper extremity bypass. J Hand Surg Am
16. Foucher G, van Genechten F, Merle N, et al. A compound radial artery forearm flap in hand surgery: an original modification of the Chinese forearm flap. Br J Plast Surg
17. Goldschlager R, Rozen WM, Ting JW, et al. The nomenclature of venous flow-through flaps: updated classification and review of the literature. Microsurgery
18. Bullocks J, Naik B, Lee E, et al. Flow-through flaps: a review of current knowledge and a novel classification system. Microsurgery
19. Valdatta L, Tuinder S, Buoro M, et al. Lateral circumflex femoral arterial system and perforators of the anterolateral thigh flap: an anatomic study. Ann Plast Surg
20. Wong M, Kiat DT, Sebastin SJ, et al. Heterodigital vascular island flap for simultaneous resurfacing and revascularization of digits. Ann Plast Surg
21. Titley OG, Chester DL, Park AJ. A-a type, arterialized, venous, flow-through, free flap for simultaneous digital revascularization and soft tissue reconstruction-revisited. Ann Plast Surg
22. Brandt K, Khouri RK, Upton J. Free flaps as flow-through vascular conduits for simultaneous coverage and revascularization of the hand or digit. Plast Reconstr Surg
23. Bacakoglu A, Ozkan MH, Muratli KS, et al. Secondary delayed venous ischemia in flow-through radial forearm free flaps: a novel treatment technique. Plast Reconstr Surg
. 2002;110:552–557, 558-559.
24. Faries PL, Logerfo FW, Arora S, et al. A comparative study of alternative conduits for lower extremity revascularization: all-autogenous conduit versus prosthetic grafts. J Vasc Surg
25. Wilson SE. New alternatives in management of the infected vascular prosthesis. Surg Infect (Larchmt)
. 2001;2:171–175, 175-177.
26. Hsiao YC, Yang JY, Chang CJ, et al. Flow-through anterolateral thigh flap for reconstruction in electrical burns of the severely damaged upper extremity. Burns
27. Koshima I, Kawada S, Etoh H, et al. Flow-through anterior thigh flaps for one-stage reconstruction of soft-tissue defects and revascularization of ischemic extremities. Plast Reconstr Surg
28. Ao M, Nagase Y, Mae O, et al. Reconstruction of posttraumatic defects of the foot by flow-through anterolateral or anteromedial thigh flaps with preservation of posterior tibial vessels. Ann Plast Surg
29. Sananpanich K, Tu YK, Kraisarin J, et al. Flow-through anterolateral thigh flap for simultaneous soft tissue and long vascular gap reconstruction in extremity injuries: anatomical study and case report. Injury
. 2008;39(suppl 4):47–54.
30. Kim JT, Kim CY, Kim YH. T-anastomosis in microsurgical free flap reconstruction: an overview of clinical applications. J Plast Reconstr Aesthet Surg
31. Malikov S, Magnan PE, Champsaur P, et al. Subscapular artery Y-shaped flow-through muscle flap: a novel one-stage limb salvage procedure. J Vasc Surg
32. Gooden MA, Gentile AT, Demas CP, et al. Salvage of femoropedal bypass graft complicated by interval gangrene and vein graft blowout using a flow-through radial forearm fasciocutaneous free flap. J Vasc Surg
33. Devansh S. Lateral thigh free flap with flow-through vascular pedicle. Ann Plast Surg
34. Koshima I, Saisho H, Kawada S, et al. Flow-through thin latissimus dorsi perforator flap for repair of soft-tissue defects in the legs. Plast Reconstr Surg
35. Kawamura K, Yajima H, Kobata Y, et al. Anatomy of Y-shaped configurations in the subscapular arterial system and clinical application to harvesting flow-through flaps. Plast Reconstr Surg
36. Qing L, Wu P, Liang J, et al. Use of flow-through anterolateral thigh perforator flaps in reconstruction of complex extremity defects. J Reconstr Microsurg
37. Tang J, Du W, Qing L, et al. Clinical application of flow-through chimeric anterolateral thigh perforator flap [in Chinese]. Zhongguo Xiu Fu Chong Jian Wai Ke Za Zhi
38. Chen C, Hao L, Sun W, et al. Glabrous flow-through flaps for simultaneous resurfacing, revascularization, and reinnervation of digits. Ann Plast Surg
39. Nanchahal J, Nayagam S, Khan U, et al. Standards for the management of open fractures of the lower limb. The Royal Society of Medicine Press
. 2009. Available at: http://www.bapras.org.uk/professionals/clinical-guidance/open-fractures-of-the-lowerlimb
. Accessed March 12, 2020.