- Email: [email protected]
Microsurgical Burn Reconstruction
M i c ro s u r g i c a l B u r n Reconstruction Akhil K. Seth, MDa, Jonathan S. Friedstat, MDb, Dennis P. Orgill, MD, PhDc, Julian J. Pribaz, MDd, Eric G. Halvorson, MDe,* KEYWORDS Burns Burn reconstruction Free tissue transfer Microsurgery
KEY POINTS Microsurgical free tissue transfer represents a viable option for reconstruction in burn patients when other options on the reconstructive ladder are not appropriate. Free tissue transfer can be performed during both the acute and reconstructive phases of burn patient care, however, with different sets of indications. The choice of free flap requires consideration of the specific anatomic region requiring reconstruction, the availability of donor sites, and its ultimate functional and aesthetic outcome.
Comprehensive care of burn patients requires a diverse breadth of skills, beginning with initial evaluation, followed by resuscitation, timely excision, grafting, and closure.1–4 Sometimes, however, the nature of the injury exceeds the abilities of traditional methods for closure. In these scenarios, exposure of critical structures, such as bone, joint spaces, and/or significant neurovascular structures, requires something more complex. When the defect is sizable, regional pedicled flaps can be a great option. However, when pedicled flaps are not available because of the size and/or distribution of the burn injury, free tissue transfer may be required. This requirement can be true in the acute setting, when critical structures are exposed but also when functional deficits might otherwise require serial procedures with additive downtime
and uncertain outcome. Patient care must be individualized, as patients with multiple comorbidities might be better served by serial minor procedures, whereas healthy patients might be better off with an initial free tissue transfer. Free tissue transfer offers a unique treatment option with its ability to bring vascularized, composite tissue (skin, subcutaneous fat, fascia, muscle, and/or bone) to a given defect. This article focuses on the role of free tissue transfer in the acute and reconstructive care of burn patients.
LIMITATIONS OF GRAFTS/LOCAL FLAPS One of the fundamental principles of reconstructive plastic surgery is to restore both appearance and function. This restoration is done by replacing the missing tissue components based on both the scope of what was lost and what is needed to
Disclosures: Dr D.P. Orgill is a consultant and receives research grants through Brigham and Women’s Hospital from Integra LifeSciences, KCI and the Musculoskeletal Transplant Foundation. The remaining authors have no financial relationships to disclose. This work was not supported by any sources of external funding. This work has not been previously published. All authors agree on the content of this article and have contributed to its production. a Harvard Combined Plastic Surgery Residency, 75 Francis Street, Boston, MA 02115, USA; b Division of Plastic Surgery, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA; c Division of Plastic Surgery, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA; d Division of Plastic Surgery, Morsani College of Medicine, University of South Florida, 2 Tampa General Circle, Tampa, FL 33606, USA; e Plastic Surgery Center of Asheville, 5 Livingston at Victoria, Asheville, NC 28801, USA * Corresponding author. E-mail address: [email protected] Clin Plastic Surg - (2017) -–http://dx.doi.org/10.1016/j.cps.2017.05.014 0094-1298/17/Ó 2017 Elsevier Inc. All rights reserved.
plasticsurgery.theclinics.com
INTRODUCTION
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Seth et al achieve a safe, functional, and aesthetic closure. In the setting of most burn injuries, this presents as a deficiency of skin and subcutaneous fat in the setting of a wound that is also at risk for developing an infection from the loss of skin integrity. Depending on the size of the burn, the risk of infection can be small or pose a life-threatening problem. The reason this is important is that when the problem is defined by both the missing tissue components and what else is occurring with patients (eg, the clinical course, medical comorbidities, patient goals), it becomes apparent that surgical treatment must be individualized (Fig. 1). When considering the initial steps of the reconstructive ladder for burn patients,5 limitations are immediately recognized. When wounds are deep and expose muscle, skin grafts can be placed but result in a contour deformity. In situations whereby a seal can be achieved, the use of negative pressure wound therapy (NPWT) can help to both decrease the overall size of a wound and
Fig. 1. This patient has significant flame burns of the torso. If he were healthy and stable, the approach would be different than if he were unhealthy and unstable. Fascial excision, short/frequent trips to the operating room, and simple coverage procedures are preferable in unstable patients. (Courtesy of Eric G. Halvorson, MD, Plastic Surgery Center of Asheville, Asheville, NC.)
form granulation tissue that helps lessen the contour deformity. Other increasingly complex defects can include exposure of tendons with loss of paratenon. In these instances, the use of dermal replacements can help form a vascularized bridge over the exposed tendon permitting later coverage with a skin graft, even in multiple layers.6–8 Although these techniques do work and minimize surgical morbidity, they may require significant additional time to achieve closure and have some pertinent limitations in burn patients. NPWT requires intact skin to achieve a seal and maintain suction, which can be problematic for burn patients. Additionally, when NPTW spans across joints, it can limit mobility for patients and make it challenging for physical and occupational therapists to treat the covered areas (Fig. 2). With dermal replacements, the challenge is that they are avascular and at increased risk of infection as they await vascularization. As one progresses further up the reconstructive ladder, local flaps can be tremendously helpful in both the acute and reconstructive setting. Fasciocutaneous flaps tend to more closely replace what is lost in a burn injury, such as a reverse radial forearm flap to cover a dorsal hand
Fig. 2. This patient had extensive burns treated with a modified large NPWT dressing that offered advantages over traditional dressings but did limit physical therapy. (Courtesy of Eric G. Halvorson, MD, Plastic Surgery Center of Asheville, Asheville, NC.)
Microsurgical Burn Reconstruction wound. In an acute setting, muscle flaps can be lifesaving, such as a pectoralis major flap that is rotated to cover the great vessels in the neck or the axillary vessels on the proximal arm or a gastrocnemius muscle flap to cover the patella of an exposed knee joint (Fig. 3). Although pedicle flaps have a role, they are limited based on the pattern of the burn injury and sometimes do not ideally address the defect. It is for these reasons that free tissue transfer retains a role in both acute and delayed burn reconstruction.
MICROSURGICAL INDICATIONS FOR BURNS Acute Injury Phase With a large (>20% total body surface area [TBSA]) burn injury, there are often many things occurring simultaneously that have a significant impact on flap outcomes. There are massive fluid shifts that occur during the acute resuscitation and during large excision and grafting procedures. Additionally, debridement of nonviable tissue will lead to the potential for local and/or systemic infections, which can lead to microvascular thrombosis from both local inflammatory effects as well as systemic hypotension. Systemic infections from
pneumonia, hypovolemia related to acute kidney injury requiring dialysis, rhabdomyolysis from electrical injuries, blood loss requiring multiple transfusions, and a stress response that can adversely impact glycemic control represent a small list of reasons why one would want to avoid a free flap in the acute setting. In this setting, every effort to minimize controllable risk factors must be made before considering an acute free tissue transfer. There are times, however, when devastating injuries occur that do not fit into the aforementioned scenarios seen in higher TBSA burns. Usually these are the result of deep flame or electrical injuries. In this scenario, there are reports of acute burns being treated with free flaps.9,10 In a small series from Utah on electrical burns, they successfully treated 4 patients who required 5 free flaps for their reconstruction. They were debrided aggressively and subsequently covered with acute free flaps. Although outcomes were limited, 3 of 5 of the patients were returned back to “gainful employment.”11 In terms of timing of reconstruction, the data again are limited to single-center retrospective reports. In one article from Germany reviewing their experience with 75 free flaps in 60 patients, they
Fig. 3. (A–C) This patient had exposure of the midshaft of the tibia following initial excision and grafting. He underwent debridement and soleus flap coverage with a skin graft. (Courtesy of Eric G. Halvorson, MD, Plastic Surgery Center of Asheville, Asheville, NC.)
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Seth et al found that flap loss rates were temporally related to the time performed in patients with deep flame (n 5 49) and electrical burns (n 5 26).12 They experienced a 13% (n 5 10) flap loss rate whereby 8 of 10 occurred between 5 and 21 days and all 10 occurred between 5 and 42 days. The investigators noted that they had no flap losses when they were performed at times greater than 6 weeks. In another publication from India, they demonstrated a 92% success rate in treating electrical burns 1 to 21 days after injury, with their one failure occurring on the third day with a free gracilis flap.13 Another injury pattern potentially amenable to immediate reconstruction is the deep thermal or electrical injury of the head and neck with exposed critical structures, such as calvaria with nonviable outer table, loss of the orbit, and other full-thickness defects that expose critical structures. Although the collective data are limited on ideal timing, patients should be optimized medically and surgically before free tissue transfer.
In the acute setting, free tissue transfer wound closure is typically prioritized over function and cosmesis. Nevertheless, it is important to consider functional and aesthetic concerns, as it is usually possible to incorporate them into the overall surgical plan. For example, a full-thickness cheek defect could be reconstructed with a fasciocutaneous flap, but a neurotized myocutaneous flap might be considered to restore facial nerve function (Fig. 4). Another important consideration in the acute setting is the inflammatory state of patients and its impact on the integrity of the tissue and patency of the anastomosis. Although the evidence regarding antiplatelet therapy and anticoagulation in this setting is inconclusive, it may be a consideration based on the prothrombotic state of acute burn patients. There are data to suggest that normothermia is beneficial, volume replacement between 3.5 and 6.0 mL/kg/h is helpful, vasopressors are not harmful to outcomes, and that dextran should be avoided.14
Fig. 4. (A–D) This patient had an extensive facial burn from prolonged contact with a radiator. Following initial debridement, free tissue transfer was performed for coverage. Instead of providing a simple coverage procedure, nasal reconstruction was incorporated into the surgical plan using a prelaminated forearm flap. (Courtesy of Julian J. Pribaz, MD, University of South Florida, Tampa, FL.)
Microsurgical Burn Reconstruction Reconstructive Phase After the acute injury phase has passed, wounds have been closed, and the inflammatory response has subsided, burn scars can then be assessed for possible reconstruction. The hypermetabolic response to a large burn can persist for up to 36 months after the initial injury and may impact outcomes of complex reconstructive procedures due to a prothrombotic and catabolic state.15 Once patients have passed beyond this phase, free flaps reenter the reconstructive
paradigm and can be used to address a variety of aesthetic and functional problems. Options include flaps such as functional muscle transfers, chimeric flaps, and prelaminated flaps depending on the clinical scenario (Fig. 5).
MICROSURGICAL BURN RECONSTRUCTION BY ANATOMIC REGION Head and Neck Reconstruction of the head and neck poses unique challenges, particularly in severely burned
Fig. 5. (A–E) Following recovery from an extensive burn, this patient was left without a nose and could not close his mouth. A reconstructive approach was developed using the crane principle to transfer multiple flaps using the same vascular pedicle. The descending branch of the lateral circumflex femoral artery was harvested, connected to the temporal vessels, and implanted in the neck to create a prefabricated flap for nasal reconstruction. His existing nasal coverage was turned down for lining, cartilage grafts were added, and the prefabricated flap was transferred for nasal reconstruction. The pedicle was then returned to the hair-bearing scalp to create a prefabricated flap for upper lip reconstruction. Following transfer and reconstruction of the upper lip, the proximal pedicle was then transferred to the base of the nose to augment the nasal reconstruction. Several minor refinements were included to obtain the final result. (Courtesy of Julian J. Pribaz, MD, University of South Florida, Tampa, FL.)
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Seth et al patients. As with any reconstruction, the primary goals include restoration of both aesthetic appearance (symmetry, contour, and color/texture match) as well as function (mobility, sensation, facial expression).16 Although skin grafting has been a traditional mainstay of burn reconstruction, this has often yielded disappointing results in the most visible and complex part of the body.17–23 Local flaps may be of some benefit, but these options are often limited by locoregional tissue also being burned.24 Free flap reconstruction for the head and neck has traditionally been criticized for the inability to bring in tissue with similar thickness and pliability to the native facial envelope.16 However, several reports have demonstrated their utility in treating certain burn sequelae, including exposed nasal
cartilage and scalp bone, and for extensive neck contractures or hypertrophic scarring.12,16,25–29 Furthermore, the use of chimeric or superthin flaps and adjunct techniques, such as flap prefabrication, prelamination, or pre-expansion, have improved our ability to customize distant tissue to meet the specificity and complexity needed in facial reconstruction30–37 (Fig. 6). There are myriad microsurgical options for head and neck burn reconstruction; however, the choice of flap always depends on the size of defect and available donor sites, particularly in the more extensively burned patient. In the face, it is particularly important to respect facial aesthetic units and reconstruct the entire unit when possible.18,38,39 In a large series of head and neck burns reconstructed using free tissue
Fig. 6. (A–E) This patient had extensive burns, including the face. Acute management included skin grafting, which proved inadequate in the long-term. She underwent facial reconstruction using a pre-expanded parascapular flap, a preexpanded forehead flap, and multiple refinement surgeries. (Courtesy of Julian J. Pribaz, MD, University of South Florida, Tampa, FL.)
Microsurgical Burn Reconstruction transfer, Parrett and colleagues16 reported using primarily anterolateral thigh (ALT) and parascapular free flaps in almost two-thirds of cases, followed by radial forearm, latissimus, rectus, and groin flaps. Specific flap indications and techniques were highlighted, including the use of radial forearm flaps for total nasal reconstruction when the forehead was not available or the use of rectus abdominis or latissimus flaps to resurface the scalp. For extensive or recurrent neck contractures, the parascapsular or ALT flap were often used to improve mobility and aesthetics over skin graft reconstruction by bringing in full-thickness skin and subcutaneous tissue. In addition, several flaps underwent additional modification, including pre-expansion and prefabrication to help decrease flap thickness and prelamination to create layered flaps that better matched the recipient site. Rose26 similarly reported on a study of 17 patients in which free tissue transfer was used for head and neck burn reconstruction. The investigator reported obtaining excellent aesthetic results by also using prepatterned composite flaps and preferentially using thin or fasciocutaneous flaps. Flaps used included the radial forearm, scapular, iliac osteocutaneous, and temporoparietal free flaps. Limitations are noted in both of the aforementioned studies, including the need for complex microsurgical anastomoses. However, both studies report a relatively high success rate, with comparable flap loss rates of 6%.16,26 Another inherent disadvantage addressed is the thickness of flaps, which can mask facial expression and require operative revisions to achieve an acceptable result.16,26 Parrett and colleagues16 reported that 64% of patients required some type of debulking procedure, usually on an outpatient basis. Rose26 reported that his results were optimized by an attempt to sculpt flaps to simulate normal planes and contours at the time of free tissue transfer inset.
Trunk Reconstruction of the thorax and trunk uses the same general principles with regard to the need for free tissue transfer and flap selection.40 In burn patients, extensive burns that preclude the use of skin grafts or local tissue in a pedicled fashion may warrant the use microsurgical reconstruction. Defect size and donor site availability are the primary determinants of flap choice. Smaller defects are typically addressed with fasciocutaneous or adipo-cutaneous flaps, such as the ALT, radial forearm, and scapular/parascapular flaps.
Larger defects may require more bulk, which can be provided by muscle flaps, such as the latissimus or rectus abdominis. With the potential for very large defects given the surface area encompassed by the thorax and trunk, pre-expanded parascapular or ALT flaps have been described to help provide larger amounts of tissue.41 A unique concern for thoracic burn patients is the downstream impact of their burns on respiratory function. In addition to any internal respiratory tract damage, extensive hypertrophic scarring can restrict thoracic expansion, which has traditionally been treated with scar release or escharotomy and skin grafting.42 However, skin grafts can contract secondarily, which may continue to limit thoracic expansion. Angrigiani and colleagues43 looked at a series of 16 burn patients with anterior thoracic burns who had previously received either conservative therapy or skin grafts that failed with regard to improvement in their respiratory expansion. All patients underwent scar release and immediate resurfacing with a free flap, preferentially ALT flaps in men and deep inferior epigastric perforator or superficial inferior epigastric artery flaps in women. They demonstrated significant improvements in quantitative respiratory function, including the mean percentage of forced vital capacity, percentage of forced expiratory volume in the first second of expiration, and overall thoracic circumference with minimal complications at 2.5 years of follow-up.
Upper Extremity Upper extremity reconstruction in burn patients can vary in complexity, ranging from pure coverage procedures for limb salvage to sophisticated procedures to restore the intricate functions of the hand. The upper extremity is also the most prone to burns secondary to high-voltage injuries, which can result in more extensive soft tissue damage. As in the head and neck region, local or pedicled flap options for reconstruction become limited depending on the extent of adjacent burned tissue. Depending on the size of the defect and its location relative to tendons and joints, where a gliding surface is required, a variety of free flaps can be used.40 The radial forearm and lateral arm flap are thin fasciocutaneous flaps that allow for resurfacing of defects with minimal depth, but donor site availability and morbidity are limiting factors. Other perforator flaps have also been used for larger or deeper defects; muscle flaps, including the latissimus dorsi, rectus, or gracilis flaps, can be used or chimeric flaps from the subscapular system (scapular, parascapular flaps) where bone from the scapula can also be harvested.
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Seth et al Several investigators have reported their experience with upper extremity burn reconstruction, describing outcomes in both electrical injuries and topical burns. Koul and colleagues13 described a series of 13 patients who experienced high-voltage electrical burns primarily in the upper extremity using several different flaps, including latissimus dorsi, temporoparietal fascia, parascapular, ALT, gracilis, and lateral arm flaps. All cases were performed in the early period after the initial injury (24 hours to 3 weeks) with only 1 flap failure. They concluded that with meticulous debridement and the use of recipient vessels remote from the burned area (ie, the zone of injury), microvascular reconstruction acutely following upper extremity burns is feasible and effective. Similarly, Researchers at the University of Heidelberg12,44,45 have published several series looking at their experience with free tissue transfer for upper extremity burn reconstruction. In their most recent series they describe the use of 42 free flaps for the reconstruction of burned upper extremities in 35 patients.44 A variety of free flaps were used in both traditional burn and high-voltage electrical injuries. For electrical injuries, they preferred the use of acute muscle free flaps, whereas for traditional burn reconstruction they preferred delayed
reconstruction. Interestingly, most of their flap failures occurred in the early stage, 5 to 21 days after the burn injury. They concluded that their results highlight the differences between thermal and high-voltage injures, each requiring tailored interventions depending on the extent of injury and resultant defect.
Lower Extremity Burn reconstruction in the lower extremity is guided by principles that are similar to that of the upper extremity, including the use limb salvage principles.40 Dorsal foot and heel coverage can be satisfactorily achieved with fascial or fasciocutaneous flaps, allowing for tendon gliding and joint mobility by minimizing soft tissue bulk.12 Larger defects more proximal on the leg can be covered with a muscle flap or ALT flap, providing reliable and supple soft tissue to resurface the excised and debrided areas of burn.40 As in the hand, the size of the defect and the need for motion of tendons or joints within the defect are crucial considerations in flap selection (Fig. 7). Limited literature is dedicated to the reconstruction of the burned lower extremity, with many series focusing on reconstruction following burns
Fig. 7. (A–C) This patient had a burn to the foot that exposed the right metatarsal joint of the great toe following debridement. Coverage was performed with an ALT flap during his initial hospitalization to allow an early return to work. He subsequently underwent an outpatient debulking procedure. (Courtesy of Eric G. Halvorson, MD, Plastic Surgery Center of Asheville, Asheville, NC.)
Microsurgical Burn Reconstruction in any extremity. Baumeister and colleagues12 reported a larger series of patients in which 28 underwent lower extremity reconstruction with a variety of free flaps, each customized to the patients. Their approach included the use of chimeric flaps based on the subscapular system to provide more tissue or different types of tissue including bone as needed. Ofer and colleagues45 looked specifically at electrical burn injures, reconstructing 10 lower extremity wounds with good results and minimal complications. In both series, the distal lower extremities (eg, foot, ankle, lower leg) were the most common sites requiring free tissue transfer, as would be expected. Also of particular interest in the extremities is the treatment of circumferential contractures at the level of joints, such as the knee or ankle.46 Supplying free tissue to these areas following scar release provides the pliability needed to reestablish motion across these joints that cannot be achieved with a skin graft reconstruction.
REFERENCES 1. Baxter CR, Shires T. Physiological response to crystalloid resuscitation of severe burns. Ann N Y Acad Sci 1968;150(3):874–94. 2. Engrav LH, Heimbach DM, Reus JL, et al. Early excision and grafting vs. nonoperative treatment of burns of indeterminate depth: a randomized prospective study. J Trauma 1983;23(11):1001–4. 3. Burke JF, Bondoc CC, Quinby WC, et al. Primary surgical management of the deeply burned hand. J Trauma 1976;16(8):593–8. 4. Sheridan RL, Hurley J, Smith MA, et al. The acutely burned hand: management and outcome based on a ten-year experience with 1047 acute hand burns. J Trauma 1995;38(3):406–11. 5. Thorne CH. Chapter 1: techniques and principles in plastic surgery. In: Thorne CH, editor. Grabb and Smith’s plastic surgery. 7th edition. Philadelphia: Wolters Kluwer/Lippincott Williams and Wilkins; 2014. p. 1–12. 6. Lee LF, Porch JV, Spenler W, et al. Integra in lower extremity reconstruction after burn injury. Plast Reconstr Surg 2008;121(4):1256–62. 7. Jeng JC, Fidler PE, Sokolich JC, et al. Seven years’ experience with Integra as a reconstructive tool. J Burn Care Res 2007;28(1):120–6. 8. Heimbach D, Luterman A, Burke J, et al. Artificial dermis for major burns. A multi-center randomized clinical trial. Ann Surg 1988;208(3):313–20. 9. Orgill DP, Pribaz JJ, Morris DJ. Local fasciocutaneous flaps for olecranon coverage. Ann Plast Surg 1994;32:27–31. 10. Orgill DP, Pribaz JJ. Functional reconstruction following electrical injury. Ann N Y Acad Sci 1999; 888:96–104.
11. Chick LR, Lister GD, Sowder L. Early free-flap coverage of electrical and thermal burns. Plast Reconstr Surg 1992;89(6):1013–9. 12. Baumeister S, Ko¨ller M, Dragu A, et al. Principles of microvascular reconstruction in burn and electrical burn injuries. Burns 2005;31(1):92–8. 13. Koul AR, Patil RK, Philip VK. Early use of microvascular free tissue transfer in the management of electrical injuries. Burns 2008;34(5):681–7. 14. Motakef S, Mountziaris PM, Ismail IK, et al. Emerging paradigms in perioperative management for microsurgical free tissue transfer: review of the literature and evidence-based guidelines. Plast Reconstr Surg 2015;135(1):290–9. 15. Gauglitz GG, Finnerty CC, Herndon DN, et al. Chapter 30: modulation of the hypermetabolic response after burn injury. In: Herndon DH, editor. Total burn care. 4th edition. New York: Elsevier; 2012. p. 355–60. 16. Parrett BM, Pomahac B, Orgill DP, et al. The role of free-tissue transfer for head and neck burn reconstruction. Plast Reconstr Surg 2007;120:1871–8. 17. Engrav LH, Heimbach DM, Walkinshaw MD, et al. Excision of burns of the face. Plast Reconstr Surg 1986;77:744–51. 18. Neale HW, Billmire DA, Carey JP. Reconstruction following head and neck burns. Clin Plast Surg 1986;13:119–36. 19. Cole JK, Engrav LH, Heimbach DM, et al. Early excision and grafting of face and neck burns in patients over 20 years. Plast Reconstr Surg 2002;109:1266–73. 20. Klein MB, Moore ML, Costa B, et al. Primer on the management of face burns at the University of Washington. J Burn Care Rehabil 2005;26:2–6. 21. Achauer BM. Reconstructing the burned face. Clin Plast Surg 1992;19:623–36. 22. Jones NF, Hardesty RA, Swartz WM, et al. Extensive and complex defects of the scalp, middle third of the face, and palate: the role of microsurgical reconstruction. Plast Reconstr Surg 1988;82:937–52. 23. Chai J, Song H, Sheng Z, et al. Repair and reconstruction of massively damaged burn wounds. Burns 2003;29:726–32. 24. Gahhos FN, Ariyan S, Cuono CB, et al. Burn wound excision and local flap closure. Ann Plast Surg 1985; 14:535–40. 25. Benmeir P, Neuman A, Weinberg A, et al. Reconstruction of a completely burned nose by a free dorsalis pedis flap. Br J Plast Surg 1991;44:570–1. 26. Rose EH. Aesthetic restoration of the severely disfigured face in burn victims: a comprehensive strategy. Plast Reconstr Surg 1995;96:1573–85. 27. Shen Z. Reconstruction of refractory defect of scalp and skull using microsurgical free flap transfer. Microsurgery 1994;15:633–8. 28. Yap LH, Earley MJ. Total eyelid reconstruction with free flap from the foot. Plast Reconstr Surg 2001; 107:284–5.
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Seth et al 29. Takushima A, Harii K, Asato H. Expanded latissimus dorsi free flap for the treatment of extensive postburn neck contracture. J Reconstr Microsurg 2002; 18:373–7. 30. Pribaz JJ, Fine N, Orgill DP. Flap prefabrication in the head and neck: a 10-year experience. Plast Reconstr Surg 1999;103:808–20. 31. Teot L, Cherenfant E, Otman S, et al. Prefabricated vascularised supraclavicular flaps for face resurfacing after postburns scarring. Lancet 2000;355: 1695–6. 32. Pribaz JJ, Fine NA. Prelamination: defining the prefabricated flap. A case report and review. Microsurgery 1994;15:618–23. 33. Pribaz JJ, Weiss DD, Mulliken JB, et al. Prelaminated free flap reconstruction of complex central facial defects. Plast Reconstr Surg 1999;104: 357–65. 34. Hallock GG. Preexpansion of free flap donor sites used in reconstruction after burn injury. J Burn Care Rehabil 1995;16:646–53. 35. Ninkovic M, Moser-Rumer A, Ninkovic M, et al. Anterior neck reconstruction with pre-expanded free groin and scapular flaps. Plast Reconstr Surg 2004;113:61–8. 36. Koshima I, Yamamoto H, Hosoda M, et al. Free combined composite flaps using the lateral circumflex femoral system for repair of massive defects of the head and neck regions: an introduction to the chimeric flap principle. Plast Reconstr Surg 1993; 92:411–20.
37. Chin T, Ogawa R, Murakami M, et al. An anatomical study and clinical cases of ‘super-thin flaps’ with transverse cervical perforator. Br J Plast Surg 2005;58:550–5. 38. Maillard GF, Clavel PR. Aesthetic units in skin grafting of the face. Ann Plast Surg 1991;26:347–52. 39. Gonzalez-Ulloa M. Restoration of the face covering by means of selected skin in regional aesthetic units. Br J Plast Surg 1956;9:212–21. 40. Ibrahim AE, Skoracki R, Goverman JG, et al. Microsurgery in the burn population - a review of the literature. Ann Burns Fire Disasters 2015;28:39–45. 41. Santanelli F, Grippaudo FR, Ziccardi P, et al. The role of pre-expanded free flaps in revision of burn scarring. Burns 1997;23:620–5. 42. Quinby WC. Restrictive effects of thoracic burns in children. J Trauma 1972;12:646–55. 43. Angrigiani C, Artero G, Castro G, et al. Reconstruction of thoracic burn sequelae by scar release and flap resurfacing. Burns 2015;41(8): 1877–82. 44. Sauerbier M, Ofer N, Germann G, et al. Microvascular reconstruction in burn and electrical burn injuries of the severely traumatized upper extremity. Plast Reconstr Surg 2007;119:605–15. 45. Ofer N, Baumeister S, Megerle K, et al. Current concepts of microvascular reconstruction for limb salvage in electrical burn injuries. J Plast Reconstr Aesth Surg 2007;60:724–30. 46. Orgill DP, Ogawa R. Current methods of burn reconstruction. Plast Reconstr Surg 2013;131:827e–36e.
KEY POINTS Microsurgical free tissue transfer represents a viable option for reconstruction in burn patients when other options on the reconstructive ladder are not appropriate. Free tissue transfer can be performed during both the acute and reconstructive phases of burn patient care, however, with different sets of indications. The choice of free flap requires consideration of the specific anatomic region requiring reconstruction, the availability of donor sites, and its ultimate functional and aesthetic outcome.
Comprehensive care of burn patients requires a diverse breadth of skills, beginning with initial evaluation, followed by resuscitation, timely excision, grafting, and closure.1–4 Sometimes, however, the nature of the injury exceeds the abilities of traditional methods for closure. In these scenarios, exposure of critical structures, such as bone, joint spaces, and/or significant neurovascular structures, requires something more complex. When the defect is sizable, regional pedicled flaps can be a great option. However, when pedicled flaps are not available because of the size and/or distribution of the burn injury, free tissue transfer may be required. This requirement can be true in the acute setting, when critical structures are exposed but also when functional deficits might otherwise require serial procedures with additive downtime
and uncertain outcome. Patient care must be individualized, as patients with multiple comorbidities might be better served by serial minor procedures, whereas healthy patients might be better off with an initial free tissue transfer. Free tissue transfer offers a unique treatment option with its ability to bring vascularized, composite tissue (skin, subcutaneous fat, fascia, muscle, and/or bone) to a given defect. This article focuses on the role of free tissue transfer in the acute and reconstructive care of burn patients.
LIMITATIONS OF GRAFTS/LOCAL FLAPS One of the fundamental principles of reconstructive plastic surgery is to restore both appearance and function. This restoration is done by replacing the missing tissue components based on both the scope of what was lost and what is needed to
Disclosures: Dr D.P. Orgill is a consultant and receives research grants through Brigham and Women’s Hospital from Integra LifeSciences, KCI and the Musculoskeletal Transplant Foundation. The remaining authors have no financial relationships to disclose. This work was not supported by any sources of external funding. This work has not been previously published. All authors agree on the content of this article and have contributed to its production. a Harvard Combined Plastic Surgery Residency, 75 Francis Street, Boston, MA 02115, USA; b Division of Plastic Surgery, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA; c Division of Plastic Surgery, Brigham and Women’s Hospital, Harvard Medical School, 75 Francis Street, Boston, MA 02115, USA; d Division of Plastic Surgery, Morsani College of Medicine, University of South Florida, 2 Tampa General Circle, Tampa, FL 33606, USA; e Plastic Surgery Center of Asheville, 5 Livingston at Victoria, Asheville, NC 28801, USA * Corresponding author. E-mail address: [email protected] Clin Plastic Surg - (2017) -–http://dx.doi.org/10.1016/j.cps.2017.05.014 0094-1298/17/Ó 2017 Elsevier Inc. All rights reserved.
plasticsurgery.theclinics.com
INTRODUCTION
2
Seth et al achieve a safe, functional, and aesthetic closure. In the setting of most burn injuries, this presents as a deficiency of skin and subcutaneous fat in the setting of a wound that is also at risk for developing an infection from the loss of skin integrity. Depending on the size of the burn, the risk of infection can be small or pose a life-threatening problem. The reason this is important is that when the problem is defined by both the missing tissue components and what else is occurring with patients (eg, the clinical course, medical comorbidities, patient goals), it becomes apparent that surgical treatment must be individualized (Fig. 1). When considering the initial steps of the reconstructive ladder for burn patients,5 limitations are immediately recognized. When wounds are deep and expose muscle, skin grafts can be placed but result in a contour deformity. In situations whereby a seal can be achieved, the use of negative pressure wound therapy (NPWT) can help to both decrease the overall size of a wound and
Fig. 1. This patient has significant flame burns of the torso. If he were healthy and stable, the approach would be different than if he were unhealthy and unstable. Fascial excision, short/frequent trips to the operating room, and simple coverage procedures are preferable in unstable patients. (Courtesy of Eric G. Halvorson, MD, Plastic Surgery Center of Asheville, Asheville, NC.)
form granulation tissue that helps lessen the contour deformity. Other increasingly complex defects can include exposure of tendons with loss of paratenon. In these instances, the use of dermal replacements can help form a vascularized bridge over the exposed tendon permitting later coverage with a skin graft, even in multiple layers.6–8 Although these techniques do work and minimize surgical morbidity, they may require significant additional time to achieve closure and have some pertinent limitations in burn patients. NPWT requires intact skin to achieve a seal and maintain suction, which can be problematic for burn patients. Additionally, when NPTW spans across joints, it can limit mobility for patients and make it challenging for physical and occupational therapists to treat the covered areas (Fig. 2). With dermal replacements, the challenge is that they are avascular and at increased risk of infection as they await vascularization. As one progresses further up the reconstructive ladder, local flaps can be tremendously helpful in both the acute and reconstructive setting. Fasciocutaneous flaps tend to more closely replace what is lost in a burn injury, such as a reverse radial forearm flap to cover a dorsal hand
Fig. 2. This patient had extensive burns treated with a modified large NPWT dressing that offered advantages over traditional dressings but did limit physical therapy. (Courtesy of Eric G. Halvorson, MD, Plastic Surgery Center of Asheville, Asheville, NC.)
Microsurgical Burn Reconstruction wound. In an acute setting, muscle flaps can be lifesaving, such as a pectoralis major flap that is rotated to cover the great vessels in the neck or the axillary vessels on the proximal arm or a gastrocnemius muscle flap to cover the patella of an exposed knee joint (Fig. 3). Although pedicle flaps have a role, they are limited based on the pattern of the burn injury and sometimes do not ideally address the defect. It is for these reasons that free tissue transfer retains a role in both acute and delayed burn reconstruction.
MICROSURGICAL INDICATIONS FOR BURNS Acute Injury Phase With a large (>20% total body surface area [TBSA]) burn injury, there are often many things occurring simultaneously that have a significant impact on flap outcomes. There are massive fluid shifts that occur during the acute resuscitation and during large excision and grafting procedures. Additionally, debridement of nonviable tissue will lead to the potential for local and/or systemic infections, which can lead to microvascular thrombosis from both local inflammatory effects as well as systemic hypotension. Systemic infections from
pneumonia, hypovolemia related to acute kidney injury requiring dialysis, rhabdomyolysis from electrical injuries, blood loss requiring multiple transfusions, and a stress response that can adversely impact glycemic control represent a small list of reasons why one would want to avoid a free flap in the acute setting. In this setting, every effort to minimize controllable risk factors must be made before considering an acute free tissue transfer. There are times, however, when devastating injuries occur that do not fit into the aforementioned scenarios seen in higher TBSA burns. Usually these are the result of deep flame or electrical injuries. In this scenario, there are reports of acute burns being treated with free flaps.9,10 In a small series from Utah on electrical burns, they successfully treated 4 patients who required 5 free flaps for their reconstruction. They were debrided aggressively and subsequently covered with acute free flaps. Although outcomes were limited, 3 of 5 of the patients were returned back to “gainful employment.”11 In terms of timing of reconstruction, the data again are limited to single-center retrospective reports. In one article from Germany reviewing their experience with 75 free flaps in 60 patients, they
Fig. 3. (A–C) This patient had exposure of the midshaft of the tibia following initial excision and grafting. He underwent debridement and soleus flap coverage with a skin graft. (Courtesy of Eric G. Halvorson, MD, Plastic Surgery Center of Asheville, Asheville, NC.)
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Seth et al found that flap loss rates were temporally related to the time performed in patients with deep flame (n 5 49) and electrical burns (n 5 26).12 They experienced a 13% (n 5 10) flap loss rate whereby 8 of 10 occurred between 5 and 21 days and all 10 occurred between 5 and 42 days. The investigators noted that they had no flap losses when they were performed at times greater than 6 weeks. In another publication from India, they demonstrated a 92% success rate in treating electrical burns 1 to 21 days after injury, with their one failure occurring on the third day with a free gracilis flap.13 Another injury pattern potentially amenable to immediate reconstruction is the deep thermal or electrical injury of the head and neck with exposed critical structures, such as calvaria with nonviable outer table, loss of the orbit, and other full-thickness defects that expose critical structures. Although the collective data are limited on ideal timing, patients should be optimized medically and surgically before free tissue transfer.
In the acute setting, free tissue transfer wound closure is typically prioritized over function and cosmesis. Nevertheless, it is important to consider functional and aesthetic concerns, as it is usually possible to incorporate them into the overall surgical plan. For example, a full-thickness cheek defect could be reconstructed with a fasciocutaneous flap, but a neurotized myocutaneous flap might be considered to restore facial nerve function (Fig. 4). Another important consideration in the acute setting is the inflammatory state of patients and its impact on the integrity of the tissue and patency of the anastomosis. Although the evidence regarding antiplatelet therapy and anticoagulation in this setting is inconclusive, it may be a consideration based on the prothrombotic state of acute burn patients. There are data to suggest that normothermia is beneficial, volume replacement between 3.5 and 6.0 mL/kg/h is helpful, vasopressors are not harmful to outcomes, and that dextran should be avoided.14
Fig. 4. (A–D) This patient had an extensive facial burn from prolonged contact with a radiator. Following initial debridement, free tissue transfer was performed for coverage. Instead of providing a simple coverage procedure, nasal reconstruction was incorporated into the surgical plan using a prelaminated forearm flap. (Courtesy of Julian J. Pribaz, MD, University of South Florida, Tampa, FL.)
Microsurgical Burn Reconstruction Reconstructive Phase After the acute injury phase has passed, wounds have been closed, and the inflammatory response has subsided, burn scars can then be assessed for possible reconstruction. The hypermetabolic response to a large burn can persist for up to 36 months after the initial injury and may impact outcomes of complex reconstructive procedures due to a prothrombotic and catabolic state.15 Once patients have passed beyond this phase, free flaps reenter the reconstructive
paradigm and can be used to address a variety of aesthetic and functional problems. Options include flaps such as functional muscle transfers, chimeric flaps, and prelaminated flaps depending on the clinical scenario (Fig. 5).
MICROSURGICAL BURN RECONSTRUCTION BY ANATOMIC REGION Head and Neck Reconstruction of the head and neck poses unique challenges, particularly in severely burned
Fig. 5. (A–E) Following recovery from an extensive burn, this patient was left without a nose and could not close his mouth. A reconstructive approach was developed using the crane principle to transfer multiple flaps using the same vascular pedicle. The descending branch of the lateral circumflex femoral artery was harvested, connected to the temporal vessels, and implanted in the neck to create a prefabricated flap for nasal reconstruction. His existing nasal coverage was turned down for lining, cartilage grafts were added, and the prefabricated flap was transferred for nasal reconstruction. The pedicle was then returned to the hair-bearing scalp to create a prefabricated flap for upper lip reconstruction. Following transfer and reconstruction of the upper lip, the proximal pedicle was then transferred to the base of the nose to augment the nasal reconstruction. Several minor refinements were included to obtain the final result. (Courtesy of Julian J. Pribaz, MD, University of South Florida, Tampa, FL.)
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Seth et al patients. As with any reconstruction, the primary goals include restoration of both aesthetic appearance (symmetry, contour, and color/texture match) as well as function (mobility, sensation, facial expression).16 Although skin grafting has been a traditional mainstay of burn reconstruction, this has often yielded disappointing results in the most visible and complex part of the body.17–23 Local flaps may be of some benefit, but these options are often limited by locoregional tissue also being burned.24 Free flap reconstruction for the head and neck has traditionally been criticized for the inability to bring in tissue with similar thickness and pliability to the native facial envelope.16 However, several reports have demonstrated their utility in treating certain burn sequelae, including exposed nasal
cartilage and scalp bone, and for extensive neck contractures or hypertrophic scarring.12,16,25–29 Furthermore, the use of chimeric or superthin flaps and adjunct techniques, such as flap prefabrication, prelamination, or pre-expansion, have improved our ability to customize distant tissue to meet the specificity and complexity needed in facial reconstruction30–37 (Fig. 6). There are myriad microsurgical options for head and neck burn reconstruction; however, the choice of flap always depends on the size of defect and available donor sites, particularly in the more extensively burned patient. In the face, it is particularly important to respect facial aesthetic units and reconstruct the entire unit when possible.18,38,39 In a large series of head and neck burns reconstructed using free tissue
Fig. 6. (A–E) This patient had extensive burns, including the face. Acute management included skin grafting, which proved inadequate in the long-term. She underwent facial reconstruction using a pre-expanded parascapular flap, a preexpanded forehead flap, and multiple refinement surgeries. (Courtesy of Julian J. Pribaz, MD, University of South Florida, Tampa, FL.)
Microsurgical Burn Reconstruction transfer, Parrett and colleagues16 reported using primarily anterolateral thigh (ALT) and parascapular free flaps in almost two-thirds of cases, followed by radial forearm, latissimus, rectus, and groin flaps. Specific flap indications and techniques were highlighted, including the use of radial forearm flaps for total nasal reconstruction when the forehead was not available or the use of rectus abdominis or latissimus flaps to resurface the scalp. For extensive or recurrent neck contractures, the parascapsular or ALT flap were often used to improve mobility and aesthetics over skin graft reconstruction by bringing in full-thickness skin and subcutaneous tissue. In addition, several flaps underwent additional modification, including pre-expansion and prefabrication to help decrease flap thickness and prelamination to create layered flaps that better matched the recipient site. Rose26 similarly reported on a study of 17 patients in which free tissue transfer was used for head and neck burn reconstruction. The investigator reported obtaining excellent aesthetic results by also using prepatterned composite flaps and preferentially using thin or fasciocutaneous flaps. Flaps used included the radial forearm, scapular, iliac osteocutaneous, and temporoparietal free flaps. Limitations are noted in both of the aforementioned studies, including the need for complex microsurgical anastomoses. However, both studies report a relatively high success rate, with comparable flap loss rates of 6%.16,26 Another inherent disadvantage addressed is the thickness of flaps, which can mask facial expression and require operative revisions to achieve an acceptable result.16,26 Parrett and colleagues16 reported that 64% of patients required some type of debulking procedure, usually on an outpatient basis. Rose26 reported that his results were optimized by an attempt to sculpt flaps to simulate normal planes and contours at the time of free tissue transfer inset.
Trunk Reconstruction of the thorax and trunk uses the same general principles with regard to the need for free tissue transfer and flap selection.40 In burn patients, extensive burns that preclude the use of skin grafts or local tissue in a pedicled fashion may warrant the use microsurgical reconstruction. Defect size and donor site availability are the primary determinants of flap choice. Smaller defects are typically addressed with fasciocutaneous or adipo-cutaneous flaps, such as the ALT, radial forearm, and scapular/parascapular flaps.
Larger defects may require more bulk, which can be provided by muscle flaps, such as the latissimus or rectus abdominis. With the potential for very large defects given the surface area encompassed by the thorax and trunk, pre-expanded parascapular or ALT flaps have been described to help provide larger amounts of tissue.41 A unique concern for thoracic burn patients is the downstream impact of their burns on respiratory function. In addition to any internal respiratory tract damage, extensive hypertrophic scarring can restrict thoracic expansion, which has traditionally been treated with scar release or escharotomy and skin grafting.42 However, skin grafts can contract secondarily, which may continue to limit thoracic expansion. Angrigiani and colleagues43 looked at a series of 16 burn patients with anterior thoracic burns who had previously received either conservative therapy or skin grafts that failed with regard to improvement in their respiratory expansion. All patients underwent scar release and immediate resurfacing with a free flap, preferentially ALT flaps in men and deep inferior epigastric perforator or superficial inferior epigastric artery flaps in women. They demonstrated significant improvements in quantitative respiratory function, including the mean percentage of forced vital capacity, percentage of forced expiratory volume in the first second of expiration, and overall thoracic circumference with minimal complications at 2.5 years of follow-up.
Upper Extremity Upper extremity reconstruction in burn patients can vary in complexity, ranging from pure coverage procedures for limb salvage to sophisticated procedures to restore the intricate functions of the hand. The upper extremity is also the most prone to burns secondary to high-voltage injuries, which can result in more extensive soft tissue damage. As in the head and neck region, local or pedicled flap options for reconstruction become limited depending on the extent of adjacent burned tissue. Depending on the size of the defect and its location relative to tendons and joints, where a gliding surface is required, a variety of free flaps can be used.40 The radial forearm and lateral arm flap are thin fasciocutaneous flaps that allow for resurfacing of defects with minimal depth, but donor site availability and morbidity are limiting factors. Other perforator flaps have also been used for larger or deeper defects; muscle flaps, including the latissimus dorsi, rectus, or gracilis flaps, can be used or chimeric flaps from the subscapular system (scapular, parascapular flaps) where bone from the scapula can also be harvested.
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Seth et al Several investigators have reported their experience with upper extremity burn reconstruction, describing outcomes in both electrical injuries and topical burns. Koul and colleagues13 described a series of 13 patients who experienced high-voltage electrical burns primarily in the upper extremity using several different flaps, including latissimus dorsi, temporoparietal fascia, parascapular, ALT, gracilis, and lateral arm flaps. All cases were performed in the early period after the initial injury (24 hours to 3 weeks) with only 1 flap failure. They concluded that with meticulous debridement and the use of recipient vessels remote from the burned area (ie, the zone of injury), microvascular reconstruction acutely following upper extremity burns is feasible and effective. Similarly, Researchers at the University of Heidelberg12,44,45 have published several series looking at their experience with free tissue transfer for upper extremity burn reconstruction. In their most recent series they describe the use of 42 free flaps for the reconstruction of burned upper extremities in 35 patients.44 A variety of free flaps were used in both traditional burn and high-voltage electrical injuries. For electrical injuries, they preferred the use of acute muscle free flaps, whereas for traditional burn reconstruction they preferred delayed
reconstruction. Interestingly, most of their flap failures occurred in the early stage, 5 to 21 days after the burn injury. They concluded that their results highlight the differences between thermal and high-voltage injures, each requiring tailored interventions depending on the extent of injury and resultant defect.
Lower Extremity Burn reconstruction in the lower extremity is guided by principles that are similar to that of the upper extremity, including the use limb salvage principles.40 Dorsal foot and heel coverage can be satisfactorily achieved with fascial or fasciocutaneous flaps, allowing for tendon gliding and joint mobility by minimizing soft tissue bulk.12 Larger defects more proximal on the leg can be covered with a muscle flap or ALT flap, providing reliable and supple soft tissue to resurface the excised and debrided areas of burn.40 As in the hand, the size of the defect and the need for motion of tendons or joints within the defect are crucial considerations in flap selection (Fig. 7). Limited literature is dedicated to the reconstruction of the burned lower extremity, with many series focusing on reconstruction following burns
Fig. 7. (A–C) This patient had a burn to the foot that exposed the right metatarsal joint of the great toe following debridement. Coverage was performed with an ALT flap during his initial hospitalization to allow an early return to work. He subsequently underwent an outpatient debulking procedure. (Courtesy of Eric G. Halvorson, MD, Plastic Surgery Center of Asheville, Asheville, NC.)
Microsurgical Burn Reconstruction in any extremity. Baumeister and colleagues12 reported a larger series of patients in which 28 underwent lower extremity reconstruction with a variety of free flaps, each customized to the patients. Their approach included the use of chimeric flaps based on the subscapular system to provide more tissue or different types of tissue including bone as needed. Ofer and colleagues45 looked specifically at electrical burn injures, reconstructing 10 lower extremity wounds with good results and minimal complications. In both series, the distal lower extremities (eg, foot, ankle, lower leg) were the most common sites requiring free tissue transfer, as would be expected. Also of particular interest in the extremities is the treatment of circumferential contractures at the level of joints, such as the knee or ankle.46 Supplying free tissue to these areas following scar release provides the pliability needed to reestablish motion across these joints that cannot be achieved with a skin graft reconstruction.
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11. Chick LR, Lister GD, Sowder L. Early free-flap coverage of electrical and thermal burns. Plast Reconstr Surg 1992;89(6):1013–9. 12. Baumeister S, Ko¨ller M, Dragu A, et al. Principles of microvascular reconstruction in burn and electrical burn injuries. Burns 2005;31(1):92–8. 13. Koul AR, Patil RK, Philip VK. Early use of microvascular free tissue transfer in the management of electrical injuries. Burns 2008;34(5):681–7. 14. Motakef S, Mountziaris PM, Ismail IK, et al. Emerging paradigms in perioperative management for microsurgical free tissue transfer: review of the literature and evidence-based guidelines. Plast Reconstr Surg 2015;135(1):290–9. 15. Gauglitz GG, Finnerty CC, Herndon DN, et al. Chapter 30: modulation of the hypermetabolic response after burn injury. In: Herndon DH, editor. Total burn care. 4th edition. New York: Elsevier; 2012. p. 355–60. 16. Parrett BM, Pomahac B, Orgill DP, et al. The role of free-tissue transfer for head and neck burn reconstruction. Plast Reconstr Surg 2007;120:1871–8. 17. Engrav LH, Heimbach DM, Walkinshaw MD, et al. Excision of burns of the face. Plast Reconstr Surg 1986;77:744–51. 18. Neale HW, Billmire DA, Carey JP. Reconstruction following head and neck burns. Clin Plast Surg 1986;13:119–36. 19. Cole JK, Engrav LH, Heimbach DM, et al. Early excision and grafting of face and neck burns in patients over 20 years. Plast Reconstr Surg 2002;109:1266–73. 20. Klein MB, Moore ML, Costa B, et al. Primer on the management of face burns at the University of Washington. J Burn Care Rehabil 2005;26:2–6. 21. Achauer BM. Reconstructing the burned face. Clin Plast Surg 1992;19:623–36. 22. Jones NF, Hardesty RA, Swartz WM, et al. Extensive and complex defects of the scalp, middle third of the face, and palate: the role of microsurgical reconstruction. Plast Reconstr Surg 1988;82:937–52. 23. Chai J, Song H, Sheng Z, et al. Repair and reconstruction of massively damaged burn wounds. Burns 2003;29:726–32. 24. Gahhos FN, Ariyan S, Cuono CB, et al. Burn wound excision and local flap closure. Ann Plast Surg 1985; 14:535–40. 25. Benmeir P, Neuman A, Weinberg A, et al. Reconstruction of a completely burned nose by a free dorsalis pedis flap. Br J Plast Surg 1991;44:570–1. 26. Rose EH. Aesthetic restoration of the severely disfigured face in burn victims: a comprehensive strategy. Plast Reconstr Surg 1995;96:1573–85. 27. Shen Z. Reconstruction of refractory defect of scalp and skull using microsurgical free flap transfer. Microsurgery 1994;15:633–8. 28. Yap LH, Earley MJ. Total eyelid reconstruction with free flap from the foot. Plast Reconstr Surg 2001; 107:284–5.
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37. Chin T, Ogawa R, Murakami M, et al. An anatomical study and clinical cases of ‘super-thin flaps’ with transverse cervical perforator. Br J Plast Surg 2005;58:550–5. 38. Maillard GF, Clavel PR. Aesthetic units in skin grafting of the face. Ann Plast Surg 1991;26:347–52. 39. Gonzalez-Ulloa M. Restoration of the face covering by means of selected skin in regional aesthetic units. Br J Plast Surg 1956;9:212–21. 40. Ibrahim AE, Skoracki R, Goverman JG, et al. Microsurgery in the burn population - a review of the literature. Ann Burns Fire Disasters 2015;28:39–45. 41. Santanelli F, Grippaudo FR, Ziccardi P, et al. The role of pre-expanded free flaps in revision of burn scarring. Burns 1997;23:620–5. 42. Quinby WC. Restrictive effects of thoracic burns in children. J Trauma 1972;12:646–55. 43. Angrigiani C, Artero G, Castro G, et al. Reconstruction of thoracic burn sequelae by scar release and flap resurfacing. Burns 2015;41(8): 1877–82. 44. Sauerbier M, Ofer N, Germann G, et al. Microvascular reconstruction in burn and electrical burn injuries of the severely traumatized upper extremity. Plast Reconstr Surg 2007;119:605–15. 45. Ofer N, Baumeister S, Megerle K, et al. Current concepts of microvascular reconstruction for limb salvage in electrical burn injuries. J Plast Reconstr Aesth Surg 2007;60:724–30. 46. Orgill DP, Ogawa R. Current methods of burn reconstruction. Plast Reconstr Surg 2013;131:827e–36e.