or weight-based enoxaparin daily (PMID: 21979849).

BURN RECONSTRUCTION

Optimizing Acute Treatment to Minimize the Need for Reconstruction

As in any plastic and reconstructive surgery case, meticulous planning and foresight is imperative.

During the acute burn injury stages, emphasis should be placed on general coverage of burn wounds and

large flaps and local tissue rearrangements should be delayed. If there is a high likelihood that the

patient might need a flap or local tissue rearrangement in the future, the region of graft harvest should

be carefully planned. For example, if a patient has a large neck burn or exposed lower extremity

tendons or bone and if an anterolateral thigh flap would help, then the thigh should be avoided as a

donor site. Surgeons should consider the fact that a meshed skin graft will have an abnormal appearance

once it heals as well as causing increased hypertrophic scarring. Donor sites should be harvested from

inconspicuous locations in case a hypertrophic scar results. Other examples requiring acute

reconstructive surgery include eyelid contracture with exposure keratitis and cervical contractures

causing airway issues. Once acute grafts and donor sites have healed patients and physicians should

focus on maximizing normal scar healing. Normal wound healing requires a balance in the hydration of

the wound and water-based moisturizers should be encouraged. Silicone sheeting or other occlusive

dressings can help in early hydration of the wound.85–87 Additionally, attempts should be made to

minimize tension off of the scar with potential applications of new devices. Compression garments are

also commonly used to decrease formation of hypertrophic scarring, though their efficacy is still

debated.88,89

Hypertrophic Scarring

Thermal burn injuries can cause tremendous morbidity, leaving the patient with not only cosmetic but

also functional impairments. Hypertrophic scarring is a major complication after burn injury with a

prevalence of 32% to 72%. Several risk factors have been identified that contribute to its development

including the localization of the burn injury, burn depth, time to heal, and skin color.90,91 While the

precise mechanism by which hypertrophic scarring occurs by remain unclear, strong and persistent

expression of transforming growth factor beta (TGF-β), focal adhesion kinase-1 (FAK1) and its receptors

have been associated with postburn hypertrophic scarring. Furthermore, a critical step in the healing

process that is altered is the transition from granulation tissue into normal scarring. During this

remodeling process, wound epithelization and scar collagen are formed but accompanied by a gradual

decrease in cellularity due to apoptosis. However, early immature hypertrophic scars caused by burns

are hypercellular and during the process of remodeling and maturing, fibroblast density does not

resemble that of normal healing.92 Apoptosis of myofibroblasts occurs 12 days after injury in normal

wound healing, but in hypertrophic scar tissue, the maximum apoptosis occurs much later at 19 to 30

months.93 These events result in a significantly higher percentage of myofibroblast and hypertrophy of

the scar tissue following severe burn injuries.

One of the key pathologic factors that must be addressed in any hypertrophic scar is tension. A new

concept of “scar rehabilitation” has emerged with the key idea being to improve the environment of the

scar without actually excising the scar. The most important step in rehabilitating the scar is release of

tension. Rather than excising the scar, this involves just releasing the area of greatest tension. Despite

not removing any tissue, a large defect is often created once the tension is released. This defect can then

be treated by adding new tissue such as a FTSG or a thick STFG. Additional ways to relieve tension

involve the use of tissue rearrangements such as a Z-plasty. A Z-plasty lengthens the scar at the expense

of width alleviating tension along the central axis of the hypertrophic scar. In general Z-plasty

rearrangements are made with 60-degree angles to maximize tissue gain without causing excess tension

on the donor site closure. Alternative V-Y advancements are useful if there is healthy tissue surrounds

the scar and can be advanced into the area of the contracture release. Both Z-plasties and V-Y

advancements relieve tension on the scar that help create the hypertrophic environment. By relieving

this tension, the scars can heal in a more normal environment and often will do so without the raised

erythematous characteristics initially present. The physiology of the Z-plasty is thought to result from

improved collagen remodeling after relief of tension.94,95 Z-plasties can be used to flatten a

hypertrophic scar or elevate a depressed scar as long as the lateral limbs extend into normal tissue. The

classic design of a Z-plasty has a central segment with limbs oriented at 60 degrees (although can be 30

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to 90 degrees) with all 3 lines of equal length (Fig. 12-9). Widening the angle of the limbs increases

percent gain in length along the central limb. Multiple Z-plasties can be designed in series to improve

contracture release in large hypertrophic scars.

Although less well studied, postburn pruritus is another significant problem affecting almost 100% of

pediatric and 87% adult patients and may persist for many years, resulting in a scratching/inflammation

cycle leading to hypertrophic scarring. Treatment options are limited for postburn pruritus, commonly

involving antihistamines and moisturization of the skin with only incomplete resolution of symptoms

and thus significant deterioration in quality of life.96

Current treatment strategies for hypertrophic scars include surgical manipulation, intralesional

corticosteroid injection, cryotherapy, and laser therapy. Surgical manipulation to remove the excess skin

remains the traditional treatment for hypertrophic scar. Recent studies investigating the role of fat

grafting into scars have shown promise to further improve function and appearance.97 Patients who

have undergone fat transfer reported satisfactory results 6 months after the procedure, indicating

considerable improvement in the features of the skin, skin texture, and thickness. Histologic

examination demonstrates new collagen deposition, neovascularization, and dermal hyperplasia in

regions treated with fat grafting, which mimics surrounding undamaged skin. Intralesional

corticosteroid suppresses the inflammatory process in wounds, diminishes collagen synthesis, and

enhances collagen degradation.98 Conversely, cryotherapy induces vascular damage that leads to anoxia

and ultimately tissue necrosis and has yielded marked improvement of hypertrophic scars.99 Efficacy is

limited to the management of small scars.

Figure 12-9. Z-plasty diagrams demonstrated tissue rearrangement used for hypertrophic burn scars.

LASER SCAR REHABILITATION

7 Since the introduction of laser treatment in the mid-1980s, additional lasers with different

wavelengths have been employed. Encouraging results have been obtained with the 585-nm wavelength

pulsed dye laser (PDL), which has been recognized as an excellent therapeutic option for the treatment

of younger hypertrophic scars.100 PDL induces the dissociation of disulfide bonds in collagen fibers and

leads to collagen fiber realignment, decreased fibroblast proliferation, and neocollagenesis. Repeated

treatments, generally between 2 and 6 are required for the optimal resolution. Shorter-pulse durations

are generally more effective for scar improvement.101 Unlike vascular malformations and hemangiomas,

scars also tend to respond better to low or medium PDL fluences, about 4 to 7 J/cm2, than to higher

fluences.102 Low-, short-pulse duration PDL fluences induce local damage to the vascular endothelium

followed by mural platelet thrombi, while high PDL fluences at longer-pulse durations tend to cause

immediate intravascular coagulation with cessation of blood flow.103 Side effects include

erythema/purpura for 7 to 14 days, hyperpigmentation, and hypopigmentation. Though these lasers are

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effective in improving scar erythema, they do not have a substantial effect on the thickness or contour

of hypertrophic scars. Controversy still exists about how much of this redness would subside if given

adequate time compared to laser treatments (Fig. 12-10).

Recently, research studies have demonstrated the benefit of fractional photothermolysis in the

treatment of hypertrophic scarring. Though the exact mechanism is unknown, this concept uses a CO2

laser (10,600 nm), which is an ablative laser that targets water in underlying tissues. The laser creates

columns of tissue destruction, which stimulates collagen production in adjacent uninjured columns of

tissue. Only a portion of the epidermis and dermis is treated with columns of energy in order to create

targeted areas of thermal damage (microthermal treatment zones). The untreated areas are a reservoir

of collagen and promote tissue regrowth. Fractional lasers, as opposed to nonfractional lasers allow for

greater penetration with decreased risk of scarring. This healing will take place outside of the acute

inflammation period and thus allow for a more normal wound healing cascade than existed at the time

of the initial excision and graft. The adjacent uninjured tissue allows for more rapid tissue regeneration

from follicles and sweat glands. Ablative lasers have a greater potential depth of treatment compared to

nonablative lasers (4 mm compared to 1.8 mm). Ablative lasers appear to be more effective for thicker

scars and those associated with restriction. Overall, this creates a more smooth appearance and allows

meshed grafts to appear less obvious. Patients have described less tightness as well as decreased

pruritus and improved overall appearance (Fig. 12-11).104

Recent studies also have demonstrated the benefit of fractional CO2

laser for pruritis. Often multimodality treatment with PDL for erythematous scars, fractional CO2

laser for thick and pruritic scars

and local tissue rearrangement to relieve tension lead to improved outcomes (Fig. 12-12).

Figure 12-10. Pulsed dye laser scar rehabilitation.

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Tissue Expansion

A tissue expander (TE) is an artificial filling device that is used to grow and expand local tissue to

reconstruct an adjacent soft tissue defect. A silicone elastomer reservoir is placed beneath the donor

tissue and slowly filled over time with saline, causing the overlying soft tissue envelope to stretch with

a net increase in surface area per unit volume. Advantages to TE are that it allows the surgeon to

reconstruct “like with like” using donor and recipient tissues that share similarities in color, thickness,

texture, and hair-bearing patterns. Larger soft tissue defects that would usually require a local flap for

reconstruction can be closed primarily using expanded local tissue, limiting donor site morbidity. A

robust angiogenic response is achieved histologically within the expanded local tissue resembling an

incisional delay phenomenon. Predictable amounts of donor tissue can be gained through the expansion

process. As a reconstructive technique, it is versatile, reliable, and repeatable, and can be applied to

many regions of the body.

On should use the largest expander possible with a base diameter approximately two to three times

that of the diameter of the soft tissue defect to be reconstructed. If the expander contains a base plate or

rigid backing, this side should be placed along the floor of the pocket to guide the direction of

expansion outward. Multiple expanders are sometimes needed to reconstruct a single defect, depending

on the availability of donor tissue. Rectangular expanders are useful on the trunk and extremities, and

result in the greatest amount of actual tissue gain, however, these should be avoided on the scalp

(approximately 40% of theoretical tissue gain). Round expanders are most commonly used in breast

reconstruction, and result in the least amount of actual tissue gain (approximately 25% of theoretical

tissue gain). Crescent expanders are useful in scalp reconstruction, and gain more tissue centrally than

peripherally. Custom expanders are helpful for irregular defects, but may be more expensive.

Figure 12-11. Ablative laser rehabilitation.

Remote filling ports are connected to the TE via silastic tubing, and can either be placed

subcutaneously (most common) for percutaneous access or externalized for direct access. It is crucial not

to make the tunnel too wide or the filling port will fall and be difficult to fill. Integrated filling ports

are located within the expander, although this design may increase the risk of inadvertent puncture of

the outer shell. The expander is usually placed adjacent and parallel to the long axis of the soft tissue

defect. If placed in the extremities, the expander should not cross any joints or impinge on joint motion.

Donor tissue must be well vascularized, free of unstable scar. Expanders should be used cautiously in

irradiated tissue or patients with poorly controlled diabetes mellitus, vascular disease, or connective

tissue disorders. The expander pocket can be developed in the subcutaneous, submuscular, or subgaleal

planes depending on the location of the soft tissue defect. The size of the expander pocket should be

individually tailored to allow the expander to lie completely flat with minimal wrinkling.

Excessive dissection should be limited to prevent expander migration postoperatively, and meticulous

hemostasis is important to minimize hematoma formation. Incisions are placed radial to the expander

pocket to minimize tension on the incision during the expansion process. Undue tension placed on the

incision during expansion can cause dehiscence and exposure of the expander. One should consider

future reconstructive options when planning incision placement such that the incisions can easily be

incorporated into planned flaps or the tissue to be resected. Endoscopic-assisted expander placement

utilizes smaller incisions and allows more direct visualization of the expander pocket, but at the expense

of a steep learning curve and altered depth perception.

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Figure 12-12. Multi-modality treatment can result in improved outcomes.

The tissue expansion process usually begins 2 weeks postoperatively and continues on a weekly basis

thereafter. The expander is filled until the patient expresses discomfort or the overlying skin blanches.

The expansion process is complete based on surgeon preference when he/she deems there is enough

donor tissue available to reconstruct the soft tissue defect. Additional “over” expansion is often

recommended to ensure adequate soft tissue coverage.

Disadvantages of tissue expansion include the need for multiple operations (at least two for placement

and removal of the expander) and outpatient visits. Definitive reconstruction is delayed secondary to

the expansion process. Specific complications related to the presence of foreign material can be as high

as 30% (e.g., infection, exposure, or extrusion). This complication risk is higher in the extremities and

scalp.

Specific Anatomic Concerns

Neck contractures are the most common wound healing complication of burn injury. Functionally this

can limit range of motion and oral competence. Surgical release of the scar contracture down to

platysma or subplatysmal layer followed by coverage with large FTSG or thick STSG followed by

aggressive range of motion 5 days after having patient in neck brace is an option for correction. If the

contraction is severe, a free tissue transfer may be required after neck release. Postoperatively it is

crucial to use compression garments for 6 to 18 months and neck bracing to keep the neck extended to

prevent contracture recurrence.

Ectropion is a common complication after periorbital burns. This deformity is caused by inadequate

tissue. If the ectropion is caused by an extrinsic contracture, scar release and provision of additional

tissue are needed to prevent recurrence.

Early ectropion requires early opthalmologic and surgical attention as it can lead to corneal abrasions.

Surgically, the contracted lid should be released and a large full thickness graft should be placed (Fig.

12-11). If excess tension, a midface lift and lateral canthoplasty can provide additional support.

Additionally, temporary or permanent tarsorrhaphies should be placed to protect the globe.

The axilla also represents a common area of contracture because it is difficult to maintain adequate

positioning in the acute phase of burn wound healing. Anatomically the axilla can be divided into the

anterior axillary fold, midaxillary line, and posterior axillary line. The Shoulder should be kept 90 to

120 degrees abduction, 15 to 20 degrees flexion (60 to 80 degrees arm elevation). There are three

grades of axillary contractures:

1A: involves anterior axillary fold

1B: involves posterior axillary fold

2: involves both axillary folds

3: involves both folds and axillary dome

Type 1 and 2 contractures can be treated with sequential release and thick STSGs or FTSGs. Type 3

contractures require local and distant flaps including parascapular and latissimus flaps. It is important to

pay attention to where hair-bearing regions are transposed. Postoperative occupational therapy and

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