Post Burns Reconstruction

BURNS RECONSTRUCTION

Introduction

In general reconstruction is deferred until hypertrophic scars have matured and optimal results obtained when scars have matured and the range of motion is normal or has plateaued with nonoperative intervention.
Exceptions to this occur in the presence of scar compromise of vital function, as in eyelid contractures with corneal exposure keratitis.

Team approach to post burns reconstruction with postoperative splinting, motion and compression garments being essential adjunct to operative treatment.

Function vs aesthetics
two pathologic processes cause limitation of motion
hypertrophicscar formation
joint contracture.

Hypertrophic scar

Hypertrophic scar formationis especially common in burns that areallowed to granulate spontaneously for longer than 3 weeks.
Best indicator of hypertrophic scar formation is the time required for healing - When woundsheal in less than 3 weeks, 33% result in hypertrophic scars, whereas of wounds that require more than 21 days to heal, 78% form hypertrophic scars (landmark paper – Dietch J Trauma 1983)
Grafting of wounds after 14 days of granulation alsoproduces poor results.
Silicone gel - hypertrophic scars lose erythematous appearance and become smoother and less oedematous. E.M. indicates reduction in collagen cohesiveness and increased number of vestibular fibroblasts. Intralesional steroid (triamcinolone) also advocated.

Wound Contracture

pathologic process involves contraction of tissue by myofibroblasts until the limits of motion are reached.
occurs during scar remodeling as collagen undergoes reorganization
resulting distortion may be either extrinsic or intrinsic.
Extrinsic contracture results from contracture of an adjacent body part—eg, ectropion from a burnof the cheek
Intrinsic contracture results from direct contracture of the region—eg,shortening of the lower lid from a burn of the liditself.

Extrinsic contracture requires release whereas intrinsic contracture requires reconstruction/resurfacing

Strategies to prevent excessive scarring and contracture.

Nonsurgical

Constant external pressure
Pressure in the order of 25mmhg(ie exceeding capillary pressure) inhibits hypertrophic scarring and pressure is now considered necessary for total period of scar maturation i.e. 1-2 yrs.
widely believed that the pressure exerted by pressure garments:
Controls collagen synthesis by limiting the supply of blood, oxygen and nutrients to the scar tissue.
Reduces collagen production to the levels found in normal scar tissue more rapidly than the natural maturation process by replacing the pressure exerted by the destroyed skin on underlying tissues
Encourages realignment of collagen bundles already present
These effects may hasten scar maturation and reduce the incidence of contractures and the need for surgical intervention
Indications include
aid hypertrophic scar maturation
prevent hypertrophic scar formation
improve the appearance of scars
control the itchiness and pain associated with hypertrophic scars
prevent contracture
increase joint mobility
measurements of the pattern of change of the erythema can be used to predict changes in scar thickness and vice versa.
Intralesional steroid injection.
Silicone topical therapy - the method of action of silicone gel is physical, chemical or a combination of both.

Surgical

Intramarginal excision better than extramarginal (Engrav) 77% scars improved on visual examination cf. 26%.
Skin graft
inhibit the proliferation of myofibroblasts in a wound bed thereby hindering wound contracture.
Full thickness grafts are superior to SSG in preventing wound contracture regardless of the thickness of the grafts. The key factor is the total percentage of dermis in the graft thus the more dermis in the graft the fewer the myofibroblasts in the wound bed.
Early burn excision and grafting noted to give better esthetic and functional results.

General principles of post burn reconstruction (Feldman)

Analyze the deformity and note distorted andabsent tissue.
Formulate a long-range plan for the reconstruction that establishes priorities, rations donor site and combines complimentary procedures. Functional needs met before esthetic needs.
Consider timing of surgery-, tangential excision before 10 days
Delay reconstruction until graft and scars have matured. Minimum of 12 months, longer in children. Use other modalities pressure etc in the interim.
Early operative intervention required.

Facilitate anesthesia during subsequent ops and to minimize extrinsic contraction on adjacent area (neck release)
Protect cornea from exposure keratitis
Protect oral aperture and competence

Release extrinsic contractures before intrinsic.
Orient scars parallel to relaxed skin tension lines.
Ration potential donor sites with priority given for facial reconstruction.
Resurface according to regional aesthetic units. Adjacent units should be covered with a single large graft whenever possible to avoid seams between esthetic territories.
Match donor skin according to thickness, color, and texture. Thicker skin grafts produce lesspostoperative contracture.
Strive for symmetry - asymmetry is obvious "do onto one side as you do onto the other".
Protect scars and grafts from UV light for at least 12 months to avoid hyper pigmentation.

Reconstruction ladder

Techniques

Skin grafts
not bulky and do not mask facial expression
FTSG better but limited donor sites
prevent future tissue contracture by virtue of the inhibitory propertiesof the transferred dermis.
contract and pigment with time.
CEA
Useful where dermis present
Flaps
useful for limb salvage, in coverage of unstable scars or a mobile joint, in cases of recurrent contracture after previous Zplasty and when large amounts of tissue are required.
bulky but normal skin.
Age is not a contraindication to free-flap use.
Tissue expansion-
local expanded skin is similar in color, texture and thickness to the area to be reconstructed but need two staged procedure
complications common (60%)
increased risk with paediatric patients, multiple expanders, use of internal ports with thetissue expanders and a history of at least two priorexpansions
use of tissue expansion in pediatric burn patients is not associatedwith more complications than tissue expansionin pediatric patients with other diagnoses.
May be used as a free flap by expanding the flap pretransfer. Advantages:
Direct closure of donor site
enhanced flap vascularity due to neovascularization at the papillary dermal level
potential increase in size of the pedicle vessel, which facilitates free transfer
resultant fat atrophy accompanying tissue expansion, which creates a thinner and more pliablecutaneous flap
drawbacks of pretransfer tissue expansion are the potential obliteration of surgical planes by the expander and edema around the flap pedicle making dissection more difficult.

Face

Management guidelines :

Precise preoperative analysis of tissues missing or displaced
Long range plan - functional before aesthetic
Timing - delay until scars and grafts mature with pressure in interim. Early intervention for functional reasons :
complete neck release to facilitate anaesthesia and help release extrinsic facial contractures
eyelid reconstruction to protect cornea
release perioral scar
Resurface according to regional aesthetic units (Gonzalez-Ulloa,1956)
Strive for facial symmetry
Match added skin to existing skin
Release extrinsic before intrinsic contractures
Orient scars parallel to relaxed skin tension lines or hide in hairline
Ration potential donor sites - set aside donor sites for face
Protect new scars and grafts from U.V. light to avoid pigmentation
Cosmetics

Scalp burns

differs from hereditary hair loss in that the scalp is tight, thin, and poorly vascularized secondary to burn cicatrix.
Despite these obstacles, there are recent reports of successful hair micrografting in burn patients directly into scar.
Options:
Local flaps (Juri or Orticochea)
A common problem with these techniques isimproper hair follicle orientation.
Tissue expansion
Up to 50% defects
Negatives of tissue expansion include prolonged treatment duration, temporaryexternal disfigurement from the expanders, andmultiple surgical procedures
Free tissue transfer – large burns
Classic choices include the parascapular flap, the radial forearm free flap,and the latissimus dorsi flap

Forehead burns

Small burns – excision and direct closure
<50% - tissue expansion
>50% - thick SSG or FTSG - replace entire forehead from eyebrow to hairline and from lateral canthus to lateral canthus.
Care taken to preserve facial nerve.
Forehead burns that involve skull cannot support skin grafts and require flap tissue for reconstruction.
Millards "crane Principle "l: a scalp flap is transposed into the defect and allowed to mature for 2 to 3 weeks then it is returned to its donor site, leaving soft tissue over exposed cranium. Soft tissue is allowed to granulate and a SSG is applied 5 -7 days later
Free flap reconstruction of aesthetic unit with scapular fasciocutaneous flap or a temporoparietal flap with vein graft.

Eyebrow reconstruction

Follow the esthetic landmarks of the eyebrow as described by Ellenbogen

Eyebrows play important role in facial expression and reconstruction after a burn injury is usually accomplished by strip hair transplant or vascularized island pedicle flaps.

Strip hair transplantharvested from the temporoparietal scalp and no wider than 5mm are the simplest way to bring hair-bearing tissue to the supraorbital ridge. Two strips usually sufficient to create a new eyebrow.
To avoid injuring the neighboring follicular bulbs, all incisions should parallel the hair shafts and defatting of the grafts should be kept to a minimum.
False hair growth seen for the first 3 to 4 weeks after grafting followed by shedding of this hair as the follicles go into telogen or resting state for the ensuing 2 - 3 months. This is followed by new hair growth.
Clodius and smahel - hair follicles in catagen phase are more suitable for grafting and show better follicular survival and they suggest pulling all hairs from the follicle a few days before grafting to cause the hair follicles to go into catagen.
Success of strip technique depends on the quality of recipient bed.

Vascularized Island pedicle flaps from the temporal scalp
Indicated if poor recipient bed due to scarring, contra lateral eyebrow is bushy or free composite graft failure.
Flap based on anterior branch of Sup temp vessels and carry an overlying island of scalp hair that is tunneled subcutaneously to the brow area
Complication: tissue loss and malalignment.
Micrografts
Surgical tattooing
Alternative to above methods

Eyelid

Restoration of eyelid function is a priority in facial reconstruction after burn
Lubricating drops and ointmentmust be used if necessary.
Generally, tarsorrhaphy is inadequate in these situations because of the lack of sufficient unburned tissue.
Either extrinsic or intrinsic scar can cause ectropion.
If extrinsic, release of the deforming scar should take care of the problem.
If intrinsic then eyelid reconstruction is required.

Extrinsic

Eyelid release incisions are designed 2-3 mm outside the ciliary margin - extend from the medial canthus laterally beyond the outer canthus; the supratarsal crease is preserved whenever possible.
At the lateral canthus, grafts should extend out and UP; never downwards
Upperlid resurfacing is best with SSG from opposite lid or inner arm and if all donors are burned prepuce may be used.
Lower lid thicker skin thus retro auricular skin gives the best match.
Resurfacing done with a single skin graft for each aesthetic unit.
A modified Tripier flap keeps the donor upper eyelid skin and orbicularis oculi muscle pedicled to the lateral canthal region, and can be used to resurface the lower eyelid.
A Fricke flap, which uses pedicled forehead skin in a similar manner, is also useful when replacing skin in the upper eyelid

Intrinsic

Intrinsic contractures require entire eyelid reconstruction.
For burns of the upper eyelid, and only if the ipsilateral lower eyelid skin is of good quality, either a Cutler-Beard or Hughes flap isan excellent alternative.
For burns of the lower eyelid, Mustardé cheek advancement flaps are suitable provided that unburned skin is available in the donor area.
In the event that complex burns have destroyed all local tissue, reconstruction withtemporoparietalis fascia pedicled or free flap may be required.

Nose

Post burn scar contracture causes foreshortening of the nose pulling up the tip and everting the nostrils in a typical "nasal ectropion". The paranasal groove and upper lip are usually distorted placing tension on the alar and rotating the alar cartilages outward to form the leading edge of the nostril. The vestibular lining and vibrissae come to lie outside the nostril, and thin atrophic scar epithelium cover the remainder of the nose.
reconstruction must address all involved layers of the nose: the mucosa, the cartilage, and the skin envelope.
Reconstruction of the of the nose involves realigning skeletal elements as well as resurfacing the exterior and the nasal cavity
Since neighboring skin of the face is generally involved in the burn, adjacent tissue transfers are often impossible.
For small defects of the ala rim, composite grafts from the ear work well
Alternatives from distant donor sites include the Washio retroauricular flap, Crane principle, Tagliacozzi inner arm flap,radial forearm free flapor dorsalis pedis free flap
Grace and Brody propose an incision at the junction of the skin and everted vestibular lining to return the lining and lower lateral cartilages to their normal position.Skin grafts, dermabrasion and overgrafting are then used to replace skin. Best skin match is from forehead or retroauricular area

Ear

Auricular burns are common and usually produce marginal loss of pinna.
Defect is typically confined to helix but may be more extensive.
biggest concern regarding burns of the ear is suppurative chondritis caused by Pseudomonas.
Prevention is far preferable to treatment of the infection, and is accomplished by controlling the local bacterial environment with topical antibiotics.
Mafenide (Sulfamylon) is the agent of choice because of its deep eschar penetration. Protective ear cups are also helpful in preventing infection.
Once the diagnosisof chondritis is made, incision and drainage ismandatory and all necrotic tissue must be debrided.
Standard techniques for ear reconstruction apply.
small helical defects (<3 cm), scar excision and reconstruction with an Antia-Buch advancement is adequate.
For resurfacing helical defects a Davis “conchal transposition flap” in which the spared conchal structures are elevated as a composite flap and transposed to the upper third of the ear. The remaining concha and overlying skin are elevated on a narrow pedicle in the area of the crus helix and transferred superiorly; the central area itself is resurfaced with a skin graft.

For more extensive deformities temporoparietal fascia as a pedicle island covering a cartilage framework
Skin expansion is limited by scar tissue anchoring the skin to the underlying cartilage and thus is of limited value

Cheek

The burned cheek is typically resurfaced with a large full-thickness skin graft, a skin flap, or by tissue expansion.
Adhere strictly to the aesthetic unit principle to avoid unsightly and obvious breaks on the plane of the cheek. A compression masked should be worn continuously for at least 4 months to inhibit scar hypertrophy at the suture lines.
If the cervical skin is intact, the primary choice for reconstruction of the cheek is tissue expansion and advancement of the unburned skin from the neck.
Submental flap has been used for reconstruction of the beard area.

Perioral

Functional disabilities of the mouth resulting from lip ectropion include drooling, oral incontinence, constriction, feeding difficulty, speech difficulty and poor hygiene.
lower lip is released first because contractures here are more disabling and contribute to extrinsic contractures of the upper lip.

Oral commissure

commonly seen when young children chew on electrical cords
When there is full-thickness destruction of vermilion, mucosa, skin, and orbicularis muscle, the resulting contracture alters adjacent structures, displaces the commissure, and distorts facial animation.
oral appliances are tried first – worn usually for 6-12 months
must be informed of the risk of subsequent labial artery bleeding, which may occur 7 to 10 days after the injury as the eschar dries.

Surgical reconstruction

Two principal types of deformity resulting from oral cavity electric burns are those that are limited to the corner of the mouth and those that involve loss of a section of lower lip.
When the corner of the lip is destroyed, parts of the upper and lower lips adhere and interfere with full opening of the mouth. The corner of the mouth can be reconstructed by separating the adherent portions of the upper and lower lips and excising the scar.
In most cases, skin loss is negligible and only mucous membrane is required to establish the normal outline of the mouth.
final reconstruction is best achieved after the scars are allowed to soften, usually 6-12 months after the injury.

Gillies-Millard commissure repair
V-Yadvancement buccal mucosa
mucosal transposition flaps
tongue flaps (PRS 1995)
composite ventral tongue flap of mucosa and muscle
replaces destroyed mucosa and muscle bulk
disadvantage - bulky and retains its papillary appearance

Upper lip

The upper lip thus comprises three units the two lateral units and the philltrum columns itself and resurfacing should respect these units
Burn ectropion of the upper lip is released by incising both nasolabial folds and the base of the nose to let the lip fall back into its native position.
columella can be lengthened with forked flaps from the upper lip as in bilateral cleft lip repair.
A composite strip graft from the scalp or a scalp flap based on the superficial temporal artery, either pedicled or free, can be used to restore the mustache
The lateral lip unit can be considered as part of the cheek aesthetic unit itself and covered with the same graft or flap used in the cheek. If the philtrum is involved it should be left alone or resurfaced separately.
Thin FTSG give best texture for lip reconstruction.
Before applying the graft the scar should be sculpted with exaggerated philtral columns and a philtral dimple to ensure that these will be visible post grafting.

Lower lip and Chin