EXPERIENCES WITH THE FLOW-THROUGH RADIAL FOREARM FLAP AS A BRIDGE IN LOWER EXTREMITY RECONSTRUCTION OMER OZKAN, M.D.,* OZLENEN OZKAN, M.D., GAMZE BEKTAS, M.D., and ANI CINPOLAT, M.D.
Various techniques have been proposed in order to overcome recipient vessel problems in microsurgery. In cases with no suitable recipient vessels close to the defect, the flow-through flap is a valuable and reliable alternative for accessing healthy recipient vessels in a single stage. We describe our experiences with combined flaps and discuss the advantages of the flow-through radial forearm flap as a bridge. Between 2003 and 2009, eight combined flaps were used to reconstruct soft-tissue defects of lower extremities. Seven patients had acute or subacute wound with exposed bone and vascular injury caused by trauma, one had a chronic nonhealing wound. The flowthrough radial forearm flap was used as a bridge flap with combined a cover flap in all cases. Radial forearm flaps provided recipient vessel lengthening. In one patient, the distal ALT flap failed and replaced with latissimus dorsi flap. Other postoperative courses were uneventful and all of flaps survived. In one patient although the flaps were healthy, sepsis developed and the extremity was amputated. Recovery and ambulation were achieved in the remaining patients. Combined flaps with the flow-through radial forearm flap are an appropriate technique for overcoming recipient vessel problems. Although the technique involves a more complicated procedure and increases C 2015 Wiley Periodicals, the number of microvascular anastomoses, it is a valuable, safe and comfortable alternative in selected cases. V Inc. Microsurgery 36:128–133, 2016.
Extensive
tissue loss in extremities has been a major challenge for reconstructive surgeons because of the lack of healthy local and regional tissues, and adequate tissue can only be obtained with microsurgical procedures in such cases.1,2 The advent of free tissue transfer has provided multiple options that allow the preservation of and maintain both the structural and functional status of the extremities. However, the most critical step in ensuring a successful outcome in a free tissue transfer is the presence of healthy recipient vessels. A lack of safe, accessible vascular inflow and outflow sources, due either to injury or to pre-existing vascular disease, may preclude free tissue transfer or cause unfortunate results.3 Various techniques have been proposed in order to overcome these difficulties and access healthy recipient vessels. Vein or arterial graft interposition or the arteriovenous (AV) loop graft techniques are the first choices.4-11 When the use of graft techniques is not feasible, a cross-leg free flap procedure can be considered, but this has serious disadvantages, requiring strict immobilization and a two-stage procedure.12,13 In cases with no suitable recipient artery and vein, the flow-through flap is a valuable and reliable alternative for accessing healthy recipient vessels in a single stage. We describe our experience with combined flaps using the flow-through radial forearm flap as a bridge.
Department of Plastic and Reconstructive Surgery, Akdeniz University School of Medicine, Antalya, Turkey € €ltesi *Correspondence to: Omer Ozkan, M.D., Akdeniz Universitesi Tıp Faku €ktif Cerrahi A.D. B-Blok 2. Kat, Dumlupinar Bulvari, Plastik ve Rekonstru €rkiye. E-mail: [email protected] Kampus, 07070, Antalya, Tu Received 27 April 2014; Revision accepted 1 February 2015; Accepted 17 March 2015 Published online 3 April 2015 in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/micr.22410 Ó 2015 Wiley Periodicals, Inc.
PATIENTS AND METHODS
Between 2003 and 2009, eight combined flaps were used to reconstruct soft tissue defects of lower extremities. All patients were male and between 40 and 65 years of age (mean age 48 years old) (Table 1). One patient had a chronic nonhealing wound due to knee prosthesis, one had a gunshot wound and six had acute or subacute wounds caused with exposed bone and vascular injury by trauma. The defects localizations were leg, distal leg, knee, and above knee amputation stump (Table 1). One patient with crush injury in the leg was referred us by cardiovascular surgeons, after revascularization. One had a subacute wound in amputation stump with exposed bone and poor vasculature around the wound. Other patients were evaluated with angiography in terms of the status of vasculature. All the patients were determined that the circulation of leg was provided by one artery. To avoid damage to the circulation of leg, medial genicular vessels, or lateral circumflex artery and vein were selected as recipient vessels. The flow-through radial forearm flap was used as a bridge flap in all cases. All anastomoses were performed without the use of any additional interpositional vein graft. Surgical Technique
All patients were evaluated for integrity of anastomosis in the hand with Allen Test. The reconstruction of the radial artery after harvest was not planned because no abnormal circulation was determined. After surgical debridement of the wound, the recipient vessels were prepared from superior to the knee. The radial forearm flap was elevated. The course of the radial pulse was determined and the flap was outlined over the radial artery. The radial forearm flap was designed 1.5 3 21 cm and elevated with the radial artery, venae
Experiences with Chain Link Flaps in Lower Extremity Reconstruction
129
Table 1. Patient Summary
Patient
Age
Sex
Cause
Defect
1
45
M
Crush ınjury
Above-knee amputation stump Knee
2
65
M
3
40
M
Exposion of prosthesis Crush ınjury
Leg
4 5
48 43
M M
Crush ınjury Crush ınjury
Leg Leg
6 7 8
52 49 42
M M M
Crush ınjury Crush ınjury Gunshot wound
Distal leg Distal leg Distal leg
Defect size (cm)
Size of bridge flap(cm)
Size of cover flap (cm)
ALT
9 3 20
2 3 18
10 3 22
None
ALT
10 3 19
2 3 23
12 3 20
None
Latissumus MCF ALT Latissumus MCF ALT ALT ALT
18 3 23
2 3 25
20 3 25
None
14 3 16 13 3 20
1.5 3 21 2 3 22
15 3 21 15 3 24
None None
11 3 19 11 3 25 10 3 24
1.5 3 20 1.5 3 24 1.5 3 22
15 3 22 11 3 25 10 3 24
None None Distal flap failure and replacement with latissimus MCF
Flap choice
comitans, and the cephalic vein. After that the cover flap was elevated. The cover flap pedicle was anastomosed to the distal pedicle of the radial forearm flap on the backtable. The proximal pedicle of the radial forearm flap was anastomosed to the recipient vessels. An incision was made between the recipient vessel area and the defect area to embed the radial vessels. The skin island of radial forearm flap was placed to this area to release the tension over the vessels. The cover flap was sutured to the defect area. The donor area of radial forearm flap was covered primarily.
Complication
zation, and the extremity was amputated on the 25th day postoperatively. One patient with knee prosthesis was allowed to walk with full weightbearing at the end of first month. The remaining five patients were allowed to walk on crutches after 3 weeks postoperatively. Because they all had tibial fracture, they had seconder surgeries by orthopedic surgeons and their physiotherapies were followed by orthopedics. Full recovery and ambulation were achieved in the first year. CASE REPORTS Case 1
RESULTS
The radial forearm flap was used as bridge flap in all cases. The anterolateral thigh (ALT) flap was used as a cover flap in six patients, while latissimus dorsi musculocutaneous flaps were used in the other two. The size of the bridge flaps ranged from 18 to 24 cm in length and 1.5 to 2 cm in width. The size of the cover flaps ranged from 20 to 25 cm in length and 10 to 20 cm in width. Recipient vessels were prepared from superior to the knee. In all cases, radial forearm flaps provided uneventful recipient vessel lengthening. In one patient, arterial insufficiency was developed in the ALT flap, however, radial forearm flap was healty. We changed the failed distal ALT flap to a latissimus dorsi flap. We did not re-explore the proximal anastomosis and used the distal end of the flow-through radial forearm flap pedicle as a recipient artery. In the remaining patients the flaps survived completely. Donor sites of the radial forearm flaps were closed directly without using a skin graft. In one case, although the flaps were healthy, sepsis developed due to prolonged ischemia before revasculari-
A 48-year-old man presented with a crush and degloving injury that resulted in the 14 3 16 cm soft tissue defect in the middle 1/3 tibia, injury of the muscles, and exposure of the left tibial bone (Fig. 1a). The tibial fracture was fixed with an external fixator. Angiography revealed that there was no flow in the peroneal artery and the tibialis posterior artery. After surgical debridement, the medial genicular vessels were prepared as recipient vessels. The radial forearm flap (1.5 3 21 cm) was elevated as bridge flap and the anterolateral thigh flap (15 3 21 cm) was elevated as cover flap. The ALT flap pedicle was anastomosed to the distal pedicle of the radial forearm flap on the back table. The pedicle of the radial forearm flap was anastomosed to the genicular vessels. The donor area of the ALT flap was covered by a split-thickness skin graft, and the donor area of radial forearm flap was covered primarily. Postoperative recovery was uneventful, and the flaps survived completely (Figs. 1b and 1c). The length of follow-up was 2 years. The patient had seconder surgeries for tibial fractures by orthopedic surgeons. Functional recovery and ambulation were achieved at the 10th month. Microsurgery DOI 10.1002/micr
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Ozkan et al.
the distal lower extremity caused by a crush injury (Fig. 2a). The tibial fracture was fixed by orthopedic surgeons. Angiography revealed that there was no flow in the peroneal artery and the tibialis anterior artery. Frequent wound debridements were performed until all necrotic tissues were removed. After surgical debridement, the medial genicular vessels were prepared as recipient vessels. The radial forearm flap (1.5 3 24 cm) was elevated as bridge flap and the anterolateral thigh flap (11 3 25 cm) was elevated as cover flap. The distal pedicle of the radial forearm flap was anastomosed to the proximal pedicle of the anterolateral thigh flap on the back table (Fig. 2b). The radial forearm flap proximal pedicle was then anastomosed to the genicular vessels. The donor area of the ALT flap was covered by a splitthickness skin graft, and the donor area of radial forearm flap was closed primarily. Postoperative period was uneventful, and the flaps survived completely (Figs. 2c and 2d). The patient had seconder surgeries for tibial fracture in the first year. He was able to walk with full weightbearing at the end of first year. Follow-up period was 2 years. DISCUSSION
Figure 1. a: A 48-year-old man suffered from a crush and degloving injury. b: Immediate postoperative view. c: Late postoperative view.
Case 2
A 49-year-old man had a 11 3 25 cm soft tissue defect and necrosis of the medial and anterior aspect of Microsurgery DOI 10.1002/micr
Despite the recent advances in microsurgery, recipient vessel problems are still the most demanding and influential factors resulting in flap failure. The characteristics of healthy recipient vessels include reasonable size, good outflow, adequate distance from the zone of trauma, and appropriate length to allow tension free anastomosis.3 Under some circumstances, in some complex situations, such as extensive traumatic damage, prior radiation injury or arterial disease, healthy recipient vessels may not be close to the defect, and lengthening of the vascular pedicles may be imperative. Vein grafts are currently most commonly used to obtain healthy recipient vessels in the reconstruction of extremities. The saphenous or cephalic systems are the most versatile and readily available for interposition graft.4,5 However, according to some studies, high-flow vein grafts using cephalic and saphenous veins involve higher risks of acute thrombosis and hemorrhagic complications due to hyperperfusion,6-8 and the long vein graft needed for the pedicle increases the free flap failure rate.2,3 In an attempt to reduce the complication rate observed in vein grafts, arteriovenous loops have been described for complex cases of free flap transfer. The rationale behind these loops is the creation of a lowresistance, high-flow, long arteriovenous shunt to distant, healthy vessels that can be divided immediately (onestage procedure) or after a few days (two-stage procedure or delayed loop), providing good-quality recipient vessels close to the defect.10,11
Experiences with Chain Link Flaps in Lower Extremity Reconstruction
131
Figure 2. a: A 49-year-old man with a soft tissue defect and necrosis of the medial and anterior aspect of the distal lower extremity caused by a crush injury. b: After back table anastomosis. c: Immediate postoperative view. d: Three months after operation.
Lin et al.5 reported a case series of 65 traumatic limb injuries reconstructed with free tissue transfers using vein grafts of significant length (>20 cm for the arterial gap). They used vein grafts for arterial defects, and a temporary a-v loop in the case of both artery and vein defect. They observed a higher re-exploration rate associated with greater graft length, although this did not achieve statistical significance. In addition, in a long vein graft, because of the lack of branches, there is a high possibility of laminar flow becoming turbulent and of endothelial damage due to high velocity (unpublished data). Theoretically, a longer vein graft has a greater probability of resulting in blood stasis and therefore thrombosis. According to one review of various cardiac studies, the patency rates of arterial conduits and the low incidence of spasm are far superior to those of vein grafts.6–9 Based on the literature, the arterial graft has some distinctive advantages, such as a low incidence of arterio-
sclerosis, presence of elastic structure in the media, and adjustment to the same arterial hemodynamic characteristics and biochemical environment.8 In the light of these advantages, the descending branch of the lateral circumflex femoral artery has recently been utilized for vascular bypass grafting.8 The length of the descending branch of the lateral circumflex femoral artery depends on the length of the thigh, with a mean value of 14.3 6 2.3 cm (range, 12.6 to 17.4 cm). Additionally, the diameter of the first 12 to 15 cm is between 2.5 mm (proximal) and 1.5 mm (distal), and the two venae comitantes have diameters slightly larger than that of the artery.9 The use of the descending branch of the lateral circumflex femoral artery to lengthen the recipient vessel has its own advantages. However, anatomic variations in the vascular pedicle and the limitations of vascular graft length represent disadvantages of the technique. Another reconstructive option for large lower extremity defects with no reliable recipient artery is the crossMicrosurgery DOI 10.1002/micr
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leg free flap (or cross-bridge free-tissue transplantation).12,13 The cross-leg free flap describes a technique in which the vascular system of the contralateral leg is used as recipient and that requires strict immobilization of both legs in a cross-position with plaster casts or, in some cases, external fixators. Immobilization in a cross-leg position for a month and the use of vessels of the healthy leg represent disadvantages of this technique. Another disadvantage is that additional blood supply to the leg is not provided. Moreover, potential injury to the side of anastomosis with leg movement or damage to the vascular pedicle on the skin bridge increases complication rates. Flow-through flaps have been widely used in reconstructive surgery since the first report by Soutar et al. in 1983.14 The concept of a flow-through flap, in which both the proximal and the distal ends of the vascular pedicle of a free flap are anastamosed to provide blood flow to distal tissues.15 The principle advantage of this flap is to provide both soft tissue reconstruction and vascular defect reconstruction in a single stage. However in our cases, flow-through radial forearm flap was not used for vascular gap reconstruction in an ischemic extremity. It was used for lengthening the pedicle. In the extremities supplied by only one vessel, to prevent the damage to the circulation of extremity and not to risk the circulation of leg, we chose a recipient vessel superior to the knee, and used flow-through radial forearm flap to reach the defect area. The radial forearm flap is only used instead of vessel graft. However, the radial artery and vein bundle was not preferred to lengthen the pedicle and the radial artery and vein was harvested with a narrow skin island to cover and protect the vessels. The skin island of the harvested radial forearm flap was 1.5 cm in size and was used to minimize the tension above the vessels and anastomoses, which is an important advantage of a flow-through flap to vein or arterial graft. To the best of our knowledge, to use flowthrough radial forearm flap for lengthening the pedicle without aiming to skin coverage in the extremity is a new concept and a valuable alternative to overcome recipient vessel problems in selected cases. In composite tissue reconstruction, the radial forearm flap, latissimus dorsi flap, fibula osteocutaneous flap, and vertical rectus abdominis flap have been used as flowthrough flaps, depending on the tissue type needed.16–19 The radial forearm flap we used as a flow-through flap for lengthening the pedicle in lower extremity reconstruction is a reliable option since it poses many advantages, such as a constant surgical anatomy and a long vascular pedicle with large caliber vessels.14 The main disadvantage of radial forearm flap is significant donor site morbidity.14 However in our cases, harvesting a narrow skin island allowed primary closure of the donor site and Microsurgery DOI 10.1002/micr
reduced donor site morbidity. Thus frequent complications attendant on the radial forearm flap donor site, such as graft loss, delayed wound healing, exposure of tendons, poor esthetic results, functional deficits in the hand, and decreased sensation over the radial nerve distribution were obviated. Although any flap may be chosen as a distal flap, using a flap with a long vascular pedicle, such as the anterolateral thigh flap or latissimus dorsi flap, will increase the movement of components, facilitate bringing the components together and increase the total pedicle length. The drawbacks inherent in this method are a requirement for at least two free flap donor sites, the increased number of microvascular anastomoses and a risk of total flap loss in the event of thrombosis. CONCLUSION
Combined flaps with the flow-through radial forearm flap as a bridge represent an appropriate technique for overcoming recipient vessel problems. Although the technique requires a more complicated procedure and increases the number of microvascular anastomoses, it is a valuable alternative to other options in selected cases. ACKNOWLEDGMENTS
The authors thank the Akdeniz University Faculty of Medicine for its support for this project. None of the authors of this manuscript have any commercial association that might pose or create a conflict of interest with the information presented in the submitted manuscript. This includes consultancies, stock ownership, or other equity interests, patent licensing arrangements, and payments for conducting or publicizing the study described in the manuscript.
REFERENCES 1. Heller L, Levin LS. Lower extremity microsurgical reconstruction. Plast Reconstruct Surg 2001;108:1029-1041; quiz 1042. 2. Khouri RK, Shaw WW. Reconstruction of the lower extremity with microvascular free flaps: A 10-year experience with 304 consecutive cases. J Trauma 1989; 29:1086-1094 3. Wei FC, Suominen S. Principles and techniques of microvascular surgery. In Mathes SJ, editor. Plastic Surgery, 2nd ed. Philadelphia: Saunders Elsevier; 2006. pp 507–538. 4. Hallock GG. The interposition arteriovenous loop revisited. J Reconst Microsurg 1988; 4:155–160. 5. Lin CH, Mardini S, Lin YT, Yeh JT, Wei FC, Chen HC. Sixty-five clinical cases of free tissue transfer using long arteriovenous fistulas or vein grafts. J Trauma. 2004;56:1107-1117. 6. Suma H. Arterial grafts in coronary bypass surgery. Ann Thorac Cardiovasc Surg 1999;5:141–145. 7. Friedman JA, Piepgras DG. Current neurosurgical indications for saphenous vein graft bypass. Neurosurg Focus 2003;14:e1 8. Fabbrocini M, Fattouch K, Camporini G, DeMicheli G, Bertucci C, Cioffi P, Mercogliano D. The descending branch of lateral femoral
Experiences with Chain Link Flaps in Lower Extremity Reconstruction
9.
10. 11. 12. 13.
circumflex artery in arterial CABG: Early and midterm results. Ann Thorac Surg 2003;75:1836–1841. Matthew Seung Suk C, Eui Jong K, Jang Hyun L, Ju Yeon P, Yong Wook P, Kyung Mook L. Scalp reconstruction after resection of a large recurred proliferating trichilemmal tumor using an anterolateral thigh free flap. Arch Plast Surg 2013;40:458–460. Angel MF, Chang B, Clark N, Wong L, Ringelman P, Manson PN. Further clinical use of the interposition arteriovenous loop graft in free tissue transfers. Microsurgery 1993;14:479–481. Silveira LF, Patricio JA. Arteriovenous fistula with a saphenous long loop. Microsurgery 1993;14:444 Chen H, El-Gammal TA, Wei F, Chen H, Noordhoff MS, Tang Y. Cross-leg free flaps for difficult cases of leg defects: Indications, pitfalls, and long-term results. Trauma 1997;43:486–491. Yu ZJ, Zeng BF, Huang YC, He HG, Sui SP, Jiang PZ, Yu S. Application of the cross-bridge microvascular anastomosis when no recipient vessels are available for anastomosis: 85 cases. Plast Reconstr Surg 2004;114:1099–1107.
133
14. Soutar DS, Scheker LR, Tanner SB, McGregor A. The radial forearm flap: A versatile method for intraoral reconstruction. Br J Plast Surg 1983;36:1Y8 15. Bullocks J, Naik B, Lee E, Hollier LJ. Flow-through flaps: A review of current knowledge and a novel classification system. Microsurgery 2006; 26:4392449. 16. Chen HC, Tang YB, Noordhoff MS. Reconstruction of the entire esophagus with "chain flaps" in a patient with severe corrosive injury. Plast Reconstr Surg 1989;84:980–984. 17. Harii K, Yamada A, Nakatsuka T, Ebihara S. Reconstruction of the mandible with a vascularized iliac bone or osteocutaneous flap. Jpn J Plast Reconstr Surg 1991(31):47–58. 18. Miyamoto S, Kayano S, Umezawa H, Fujiki M, Sakuraba M. Flowthrough fibula flap using soleus branch as distal runoff: A case report. Microsurgery 2013;33:60-62. 19. Garvey PB, Clemens MW, Rhines LD, Sacks JM. Vertical rectus abdominis musculocutaneous flow-through flap to a free fibula flap for total sacrectomy reconstruction. Microsurgery 2013;33:32-38.
Microsurgery DOI 10.1002/micr
Various techniques have been proposed in order to overcome recipient vessel problems in microsurgery. In cases with no suitable recipient vessels close to the defect, the flow-through flap is a valuable and reliable alternative for accessing healthy recipient vessels in a single stage. We describe our experiences with combined flaps and discuss the advantages of the flow-through radial forearm flap as a bridge. Between 2003 and 2009, eight combined flaps were used to reconstruct soft-tissue defects of lower extremities. Seven patients had acute or subacute wound with exposed bone and vascular injury caused by trauma, one had a chronic nonhealing wound. The flowthrough radial forearm flap was used as a bridge flap with combined a cover flap in all cases. Radial forearm flaps provided recipient vessel lengthening. In one patient, the distal ALT flap failed and replaced with latissimus dorsi flap. Other postoperative courses were uneventful and all of flaps survived. In one patient although the flaps were healthy, sepsis developed and the extremity was amputated. Recovery and ambulation were achieved in the remaining patients. Combined flaps with the flow-through radial forearm flap are an appropriate technique for overcoming recipient vessel problems. Although the technique involves a more complicated procedure and increases C 2015 Wiley Periodicals, the number of microvascular anastomoses, it is a valuable, safe and comfortable alternative in selected cases. V Inc. Microsurgery 36:128–133, 2016.
Extensive
tissue loss in extremities has been a major challenge for reconstructive surgeons because of the lack of healthy local and regional tissues, and adequate tissue can only be obtained with microsurgical procedures in such cases.1,2 The advent of free tissue transfer has provided multiple options that allow the preservation of and maintain both the structural and functional status of the extremities. However, the most critical step in ensuring a successful outcome in a free tissue transfer is the presence of healthy recipient vessels. A lack of safe, accessible vascular inflow and outflow sources, due either to injury or to pre-existing vascular disease, may preclude free tissue transfer or cause unfortunate results.3 Various techniques have been proposed in order to overcome these difficulties and access healthy recipient vessels. Vein or arterial graft interposition or the arteriovenous (AV) loop graft techniques are the first choices.4-11 When the use of graft techniques is not feasible, a cross-leg free flap procedure can be considered, but this has serious disadvantages, requiring strict immobilization and a two-stage procedure.12,13 In cases with no suitable recipient artery and vein, the flow-through flap is a valuable and reliable alternative for accessing healthy recipient vessels in a single stage. We describe our experience with combined flaps using the flow-through radial forearm flap as a bridge.
Department of Plastic and Reconstructive Surgery, Akdeniz University School of Medicine, Antalya, Turkey € €ltesi *Correspondence to: Omer Ozkan, M.D., Akdeniz Universitesi Tıp Faku €ktif Cerrahi A.D. B-Blok 2. Kat, Dumlupinar Bulvari, Plastik ve Rekonstru €rkiye. E-mail: [email protected] Kampus, 07070, Antalya, Tu Received 27 April 2014; Revision accepted 1 February 2015; Accepted 17 March 2015 Published online 3 April 2015 in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/micr.22410 Ó 2015 Wiley Periodicals, Inc.
PATIENTS AND METHODS
Between 2003 and 2009, eight combined flaps were used to reconstruct soft tissue defects of lower extremities. All patients were male and between 40 and 65 years of age (mean age 48 years old) (Table 1). One patient had a chronic nonhealing wound due to knee prosthesis, one had a gunshot wound and six had acute or subacute wounds caused with exposed bone and vascular injury by trauma. The defects localizations were leg, distal leg, knee, and above knee amputation stump (Table 1). One patient with crush injury in the leg was referred us by cardiovascular surgeons, after revascularization. One had a subacute wound in amputation stump with exposed bone and poor vasculature around the wound. Other patients were evaluated with angiography in terms of the status of vasculature. All the patients were determined that the circulation of leg was provided by one artery. To avoid damage to the circulation of leg, medial genicular vessels, or lateral circumflex artery and vein were selected as recipient vessels. The flow-through radial forearm flap was used as a bridge flap in all cases. All anastomoses were performed without the use of any additional interpositional vein graft. Surgical Technique
All patients were evaluated for integrity of anastomosis in the hand with Allen Test. The reconstruction of the radial artery after harvest was not planned because no abnormal circulation was determined. After surgical debridement of the wound, the recipient vessels were prepared from superior to the knee. The radial forearm flap was elevated. The course of the radial pulse was determined and the flap was outlined over the radial artery. The radial forearm flap was designed 1.5 3 21 cm and elevated with the radial artery, venae
Experiences with Chain Link Flaps in Lower Extremity Reconstruction
129
Table 1. Patient Summary
Patient
Age
Sex
Cause
Defect
1
45
M
Crush ınjury
Above-knee amputation stump Knee
2
65
M
3
40
M
Exposion of prosthesis Crush ınjury
Leg
4 5
48 43
M M
Crush ınjury Crush ınjury
Leg Leg
6 7 8
52 49 42
M M M
Crush ınjury Crush ınjury Gunshot wound
Distal leg Distal leg Distal leg
Defect size (cm)
Size of bridge flap(cm)
Size of cover flap (cm)
ALT
9 3 20
2 3 18
10 3 22
None
ALT
10 3 19
2 3 23
12 3 20
None
Latissumus MCF ALT Latissumus MCF ALT ALT ALT
18 3 23
2 3 25
20 3 25
None
14 3 16 13 3 20
1.5 3 21 2 3 22
15 3 21 15 3 24
None None
11 3 19 11 3 25 10 3 24
1.5 3 20 1.5 3 24 1.5 3 22
15 3 22 11 3 25 10 3 24
None None Distal flap failure and replacement with latissimus MCF
Flap choice
comitans, and the cephalic vein. After that the cover flap was elevated. The cover flap pedicle was anastomosed to the distal pedicle of the radial forearm flap on the backtable. The proximal pedicle of the radial forearm flap was anastomosed to the recipient vessels. An incision was made between the recipient vessel area and the defect area to embed the radial vessels. The skin island of radial forearm flap was placed to this area to release the tension over the vessels. The cover flap was sutured to the defect area. The donor area of radial forearm flap was covered primarily.
Complication
zation, and the extremity was amputated on the 25th day postoperatively. One patient with knee prosthesis was allowed to walk with full weightbearing at the end of first month. The remaining five patients were allowed to walk on crutches after 3 weeks postoperatively. Because they all had tibial fracture, they had seconder surgeries by orthopedic surgeons and their physiotherapies were followed by orthopedics. Full recovery and ambulation were achieved in the first year. CASE REPORTS Case 1
RESULTS
The radial forearm flap was used as bridge flap in all cases. The anterolateral thigh (ALT) flap was used as a cover flap in six patients, while latissimus dorsi musculocutaneous flaps were used in the other two. The size of the bridge flaps ranged from 18 to 24 cm in length and 1.5 to 2 cm in width. The size of the cover flaps ranged from 20 to 25 cm in length and 10 to 20 cm in width. Recipient vessels were prepared from superior to the knee. In all cases, radial forearm flaps provided uneventful recipient vessel lengthening. In one patient, arterial insufficiency was developed in the ALT flap, however, radial forearm flap was healty. We changed the failed distal ALT flap to a latissimus dorsi flap. We did not re-explore the proximal anastomosis and used the distal end of the flow-through radial forearm flap pedicle as a recipient artery. In the remaining patients the flaps survived completely. Donor sites of the radial forearm flaps were closed directly without using a skin graft. In one case, although the flaps were healthy, sepsis developed due to prolonged ischemia before revasculari-
A 48-year-old man presented with a crush and degloving injury that resulted in the 14 3 16 cm soft tissue defect in the middle 1/3 tibia, injury of the muscles, and exposure of the left tibial bone (Fig. 1a). The tibial fracture was fixed with an external fixator. Angiography revealed that there was no flow in the peroneal artery and the tibialis posterior artery. After surgical debridement, the medial genicular vessels were prepared as recipient vessels. The radial forearm flap (1.5 3 21 cm) was elevated as bridge flap and the anterolateral thigh flap (15 3 21 cm) was elevated as cover flap. The ALT flap pedicle was anastomosed to the distal pedicle of the radial forearm flap on the back table. The pedicle of the radial forearm flap was anastomosed to the genicular vessels. The donor area of the ALT flap was covered by a split-thickness skin graft, and the donor area of radial forearm flap was covered primarily. Postoperative recovery was uneventful, and the flaps survived completely (Figs. 1b and 1c). The length of follow-up was 2 years. The patient had seconder surgeries for tibial fractures by orthopedic surgeons. Functional recovery and ambulation were achieved at the 10th month. Microsurgery DOI 10.1002/micr
130
Ozkan et al.
the distal lower extremity caused by a crush injury (Fig. 2a). The tibial fracture was fixed by orthopedic surgeons. Angiography revealed that there was no flow in the peroneal artery and the tibialis anterior artery. Frequent wound debridements were performed until all necrotic tissues were removed. After surgical debridement, the medial genicular vessels were prepared as recipient vessels. The radial forearm flap (1.5 3 24 cm) was elevated as bridge flap and the anterolateral thigh flap (11 3 25 cm) was elevated as cover flap. The distal pedicle of the radial forearm flap was anastomosed to the proximal pedicle of the anterolateral thigh flap on the back table (Fig. 2b). The radial forearm flap proximal pedicle was then anastomosed to the genicular vessels. The donor area of the ALT flap was covered by a splitthickness skin graft, and the donor area of radial forearm flap was closed primarily. Postoperative period was uneventful, and the flaps survived completely (Figs. 2c and 2d). The patient had seconder surgeries for tibial fracture in the first year. He was able to walk with full weightbearing at the end of first year. Follow-up period was 2 years. DISCUSSION
Figure 1. a: A 48-year-old man suffered from a crush and degloving injury. b: Immediate postoperative view. c: Late postoperative view.
Case 2
A 49-year-old man had a 11 3 25 cm soft tissue defect and necrosis of the medial and anterior aspect of Microsurgery DOI 10.1002/micr
Despite the recent advances in microsurgery, recipient vessel problems are still the most demanding and influential factors resulting in flap failure. The characteristics of healthy recipient vessels include reasonable size, good outflow, adequate distance from the zone of trauma, and appropriate length to allow tension free anastomosis.3 Under some circumstances, in some complex situations, such as extensive traumatic damage, prior radiation injury or arterial disease, healthy recipient vessels may not be close to the defect, and lengthening of the vascular pedicles may be imperative. Vein grafts are currently most commonly used to obtain healthy recipient vessels in the reconstruction of extremities. The saphenous or cephalic systems are the most versatile and readily available for interposition graft.4,5 However, according to some studies, high-flow vein grafts using cephalic and saphenous veins involve higher risks of acute thrombosis and hemorrhagic complications due to hyperperfusion,6-8 and the long vein graft needed for the pedicle increases the free flap failure rate.2,3 In an attempt to reduce the complication rate observed in vein grafts, arteriovenous loops have been described for complex cases of free flap transfer. The rationale behind these loops is the creation of a lowresistance, high-flow, long arteriovenous shunt to distant, healthy vessels that can be divided immediately (onestage procedure) or after a few days (two-stage procedure or delayed loop), providing good-quality recipient vessels close to the defect.10,11
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Figure 2. a: A 49-year-old man with a soft tissue defect and necrosis of the medial and anterior aspect of the distal lower extremity caused by a crush injury. b: After back table anastomosis. c: Immediate postoperative view. d: Three months after operation.
Lin et al.5 reported a case series of 65 traumatic limb injuries reconstructed with free tissue transfers using vein grafts of significant length (>20 cm for the arterial gap). They used vein grafts for arterial defects, and a temporary a-v loop in the case of both artery and vein defect. They observed a higher re-exploration rate associated with greater graft length, although this did not achieve statistical significance. In addition, in a long vein graft, because of the lack of branches, there is a high possibility of laminar flow becoming turbulent and of endothelial damage due to high velocity (unpublished data). Theoretically, a longer vein graft has a greater probability of resulting in blood stasis and therefore thrombosis. According to one review of various cardiac studies, the patency rates of arterial conduits and the low incidence of spasm are far superior to those of vein grafts.6–9 Based on the literature, the arterial graft has some distinctive advantages, such as a low incidence of arterio-
sclerosis, presence of elastic structure in the media, and adjustment to the same arterial hemodynamic characteristics and biochemical environment.8 In the light of these advantages, the descending branch of the lateral circumflex femoral artery has recently been utilized for vascular bypass grafting.8 The length of the descending branch of the lateral circumflex femoral artery depends on the length of the thigh, with a mean value of 14.3 6 2.3 cm (range, 12.6 to 17.4 cm). Additionally, the diameter of the first 12 to 15 cm is between 2.5 mm (proximal) and 1.5 mm (distal), and the two venae comitantes have diameters slightly larger than that of the artery.9 The use of the descending branch of the lateral circumflex femoral artery to lengthen the recipient vessel has its own advantages. However, anatomic variations in the vascular pedicle and the limitations of vascular graft length represent disadvantages of the technique. Another reconstructive option for large lower extremity defects with no reliable recipient artery is the crossMicrosurgery DOI 10.1002/micr
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leg free flap (or cross-bridge free-tissue transplantation).12,13 The cross-leg free flap describes a technique in which the vascular system of the contralateral leg is used as recipient and that requires strict immobilization of both legs in a cross-position with plaster casts or, in some cases, external fixators. Immobilization in a cross-leg position for a month and the use of vessels of the healthy leg represent disadvantages of this technique. Another disadvantage is that additional blood supply to the leg is not provided. Moreover, potential injury to the side of anastomosis with leg movement or damage to the vascular pedicle on the skin bridge increases complication rates. Flow-through flaps have been widely used in reconstructive surgery since the first report by Soutar et al. in 1983.14 The concept of a flow-through flap, in which both the proximal and the distal ends of the vascular pedicle of a free flap are anastamosed to provide blood flow to distal tissues.15 The principle advantage of this flap is to provide both soft tissue reconstruction and vascular defect reconstruction in a single stage. However in our cases, flow-through radial forearm flap was not used for vascular gap reconstruction in an ischemic extremity. It was used for lengthening the pedicle. In the extremities supplied by only one vessel, to prevent the damage to the circulation of extremity and not to risk the circulation of leg, we chose a recipient vessel superior to the knee, and used flow-through radial forearm flap to reach the defect area. The radial forearm flap is only used instead of vessel graft. However, the radial artery and vein bundle was not preferred to lengthen the pedicle and the radial artery and vein was harvested with a narrow skin island to cover and protect the vessels. The skin island of the harvested radial forearm flap was 1.5 cm in size and was used to minimize the tension above the vessels and anastomoses, which is an important advantage of a flow-through flap to vein or arterial graft. To the best of our knowledge, to use flowthrough radial forearm flap for lengthening the pedicle without aiming to skin coverage in the extremity is a new concept and a valuable alternative to overcome recipient vessel problems in selected cases. In composite tissue reconstruction, the radial forearm flap, latissimus dorsi flap, fibula osteocutaneous flap, and vertical rectus abdominis flap have been used as flowthrough flaps, depending on the tissue type needed.16–19 The radial forearm flap we used as a flow-through flap for lengthening the pedicle in lower extremity reconstruction is a reliable option since it poses many advantages, such as a constant surgical anatomy and a long vascular pedicle with large caliber vessels.14 The main disadvantage of radial forearm flap is significant donor site morbidity.14 However in our cases, harvesting a narrow skin island allowed primary closure of the donor site and Microsurgery DOI 10.1002/micr
reduced donor site morbidity. Thus frequent complications attendant on the radial forearm flap donor site, such as graft loss, delayed wound healing, exposure of tendons, poor esthetic results, functional deficits in the hand, and decreased sensation over the radial nerve distribution were obviated. Although any flap may be chosen as a distal flap, using a flap with a long vascular pedicle, such as the anterolateral thigh flap or latissimus dorsi flap, will increase the movement of components, facilitate bringing the components together and increase the total pedicle length. The drawbacks inherent in this method are a requirement for at least two free flap donor sites, the increased number of microvascular anastomoses and a risk of total flap loss in the event of thrombosis. CONCLUSION
Combined flaps with the flow-through radial forearm flap as a bridge represent an appropriate technique for overcoming recipient vessel problems. Although the technique requires a more complicated procedure and increases the number of microvascular anastomoses, it is a valuable alternative to other options in selected cases. ACKNOWLEDGMENTS
The authors thank the Akdeniz University Faculty of Medicine for its support for this project. None of the authors of this manuscript have any commercial association that might pose or create a conflict of interest with the information presented in the submitted manuscript. This includes consultancies, stock ownership, or other equity interests, patent licensing arrangements, and payments for conducting or publicizing the study described in the manuscript.
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Microsurgery DOI 10.1002/micr
