Seminar on Reconstructive Surgery

Reconstructive surgery for burn patients

C. M. HO, L. K. Lam and William I. Wei

Abstract

Reconstructive surgery in burn patients is difficult because of the intense scarring and thenecessity to carry out multiple operative procedures for different reconstructive needs in a singlepatient. The primary aim of the surgeon is to prevent hypertrophic scar by early wound closure,and proper postburn treatment using a combination of silicone gel, splinting, and pressuretherapy. Reconstructive procedures should be deferred until the wounds have matured. Accuratepreoperative assessment and appreciation of the true tissue deficiency, appropriate applicationof different reconstructive options, and the establishment of the priorities of reconstruction inrelation to individual requirements are essential for a successful outcome. In general, functionalneeds have to be met before attending to aesthetic concerns and priority should be given torestore active before passive function. Different reconstructive options using direct closure, skingrafts, flaps, free tissue transfer, and tissue expansion are discussed.

Keywords: Burn; Hypertrophic scar; Reconstruction

Introduction

Survival after severe burn injury has improved sub-stantially during the past 50 years because of therefined fluid resuscitation and nutritional feedingregimens, the use of topical antimicrobial agents, andearly operative therapy. Despite the improvement insurvival rate, it is inevitable that thermal injury to theskin, except for very superficial burns, results in per-manent scarring,. In fact, proliferative scar formation,either hypertrophic scar or keloid, is a common se-quel of burn injury, especially in Oriental patients.

Prevention of hypertrophic scars

The most effective treatment of hypertrophic scar isprevention. Scar hypertrophy typically begins aboutthree weeks after final wound closure and is most

Department of Surgery, The University of Hong Kong, Queen Mary Hos-pital, Pokfulam, Hong KongC. M. Ho, FRCSE, FRACSL K. Lam, FRCSE, FRACSWilliam 1. Wei, MS, FRCSECorrespondence to: Dr C. M. Ho

exuberant by the second or third month. The scarthen slowly regresses over the next 12 to 24 months.Hypertrophic scars appear to be related to woundcontraction, which is a normal process of woundhealing. It is neither possible nor desirable to preventwound contraction but it may be possible to preventthe abnormal continuation of wound contractionleading to a contracture or deformity.

At present we have enough evidence to believethat hypertrophic scarring is most likely in patientswhose wound healing is delayed for more than 21days. Deitch and his colleagues' noted that the bestprognostic indicator of subsequent hypertrophic scarformation was the time required for healing. Whenthe wound healed in less than 21 days, 33% resultedin hypertrophic scars, compared to 78% of those re-quiring more than 21 days to heal. Robson2 alsodemonstrated that hypertrophic scars were related tothe amount of time that the wound was allowed toremain in the inflammatory phase before moving intothe proliferative phase. He suggests that burn woundsshould be excised and closed very early to decreasethe length of the inflammatory phase. For the samereason, it is important to have a successful skin graft'take' at the time of initial excision and grafting dur-ing the acute care of the burn wound. These

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advantages are best shown in hand burns where ag-gressive surgical management together with proper-splinting and early mobilization is responsible for thegood long-term results. This is because the oedema,inflammation and immobility that accompany a ther-mal injury can render the hand useless through rapidjoint stiffening with attendant adhesions and scarcontracture.

Another technique to decrease hypertrophic scar-ring is the application of pressure. It has been shownthat in hypertrophic scars treated with pressure, thecollagen nodules common in untreated hypertrophicscars disappear and the collagen bundles become ori-ented and aligned through mechanical traction untilthe fibres are parallel to the force of stress.3, 4 Pressuregarments customized to the individual patient shouldbe applied as soon as possible after the wound iscompletely healed. Pressure therapy should be givenfor the total period of scar maturation, a process thatoften takes one to two years.

In addition to pressure garments, silicone gel couldbe applied directly on the scar. The gel improves thescars to a greater degree and much faster than pres-sure alone and keeps the skin soft and supple.5, 6

As previously mentioned, the process of scarmaturation takes one to two years. It is thereforeimportant to have splinting and exercises after theburn wound heals while the scar is still immature.Without the splintage and exercises, wound contrac-tion will act unopposed and promote distortionproducing disfigurement and functional l imitation.

Management guidelines

Reconstructive procedures should be deferred untilthe wounds have matured. This may take up to twoyears in adults and even longer in children. Duringthis time, external pressure by means of splints andelastic masks is recommended to minimize scarhypertrophy.

Early reconstruction should be performed only ifthe deformity is progressive or causes functionaldeficit, which occurs not infrequently. An example issevere ectropion of the eyelid where early reconstruc-tion is necessary to prevent exposure keratitis. Liprelease and reconstruction may be necessary to pre-vent sagging, drooling and poor nutritional statusfrom an inadequate oral aperture. Complete neck re-lease may also be required to facilitate anaesthesiaduring subsequent operations. It also helps to mini-mize extrinsic facial contractures in the perioral region,cheek, and lower eyelids.

In a severely burned patient, multiple proceduresare often required and may take several years to re-construct. A surgeon should document everydeformity accurately and carry out a precise analysis

of structures or tissues tha t are missing or displaced.The deformity could be caused by contraction of anadjacent structure, e.g., ectropion from a burn of thecheek, or the in jury and contraction of the partitself, such as the shortening of the lower lid from aburn. It is important to appreciate both the extrinsicand intrinsic factors causing the deformity. Recon-struction involves release or the extrinsic contractedscar and resurfacing the area of intrinsic contracture.Appreciation of the true tissue deficiency, particularlyalter releasing the intrinsic or extrinsic contractures,may be the most important step in reconstruction.7

A long-range plan has to be formulated to estab-lish priorities, ration donor sites, and combinecomplementary procedures. The patient has to beconsidered as a whole in relation to his/her age, life-style, occupation, and physical demands. In principle,functional needs should be met before at tending toaesthetic concerns and higher priority should be givento restore active before passive function. However,cosmetic reconstruction may also improve the patient'sfunction and daily activities and help him/her toreturn to work earlier.

It cannot be overemphasized that post-operativesplinting and/or pressure garments should be givenafter each reconstructive procedure. Lack of attentionto these details jeopardizes optimal functional andaesthetic results. Patients should also be advised toprotect the new scars and grafts from ultraviolet ra-diation to avoid hyperpigmentation.

Once the priorities of reconstruction have been de-termined, the techniques available are numerous anddiversified. The most simple method which will pro-duce the desired result should be chosen. Directclosure, skin grafts, flaps, free tissue transfer, andtissue expansion are the main armamentarium of thereconstructive burn surgeon.

Direct closure

Direct closure after excision of the scar is the mostsimple method in burn reconstruction. In planningscar revision, it is important to appreciate the normalwound healing process and the factors that make ascar less than optimal. The common reasons whyscars are unacceptable are: failure of proper dermalapproximation, direction of the wound not parallel torelaxed skin tension lines, and a pathological exten-sion of normal wound contraction resulting in acontracture. During scar revision, the new woundsshould be realigned to the skin creases or hidden inthe hairline when applicable. The skin closure shouldbe meticulous and accurate approximation of skinedges is important.

Z-plasty is a technique by which two triangularskin flaps are interchanged in position to gain lengthalong a scar or skin-fold at the expense of the adjacent

Ho et al.: Reconstructive surgery for burn patients 259

Fig. 1. (a) Multiple Z-plasty planned to release web contracture of axilla,(b) Contracture released and multiple flaps raised,(c) Result at three months after operation.

tissues. Its appropriate use allows the reconstructivesurgeon to lengthen a contracted scar (Fig, 1), obliter-ate a web contracture, add to an area of deficienttissue, and change the direction of a scar.8

Skin grafts

When a scar contracture is incised or excised, theedges retract widely and make tissue deficiency ap-parent. In most instances, direct closure is impossibleand skin grafts are the next most common technique.A split-thickness or full-thickness skin graft will re-place the deficiency and improve the scar. Afull-thickness skin graft will provide a better qualityand colour match but the availability of the donorsites is limited (Fig. 2).

When choosing the donor site, the colour, texture,vascularity, thickness and hair-bearing nature of theskin need to be considered. In general, the nearer thedonor site is to the recipient site, the more closely theskin will match. This is particularly true in recon-struction of the face. Although the facial skin isobviously the best match, it is seldom available. The

adjacent area above the nipple line gives the next bestcolour match,

Whether to use skin grafts or skin flaps in facialresurfacing continues to be controversial. Proponentsof skin grafts argue that grafts are not bulky and donot mask facial expression. Grafts, on the other hand,tend to contract and hyperpigment with time, andeven the best grafts lack a normal surface texture. Ingeneral, a. burned cheek in an unscarred face is bestresurfaced with a flap because a graft would look likean alien patch, even if replaced as an aesthetic unit. Ifthe entire face needs to be resurfaced, a graft is moreappropriate than a flap. If not enough 'blush' skin isavailable, the entire reconstruction should be per-formed using skin of the same colour and texture.

Full-thickness or very thick split-thickness graftsare preferable in total facial resurfacing because thethicker the graft, the milder the contracture and thebetter the surface texture. In order to achieve a satis-factory result, virtually 100% 'take' of a graft is neededfor a satisfactory result. It may be wise to wait 24hours after scar excision to ensure perfect haemostasiabefore applying the skin graft.

260 J Hong Kong Med Assoc Vol. 46, No. 4, December 1994

Fig. 2. (a) Ectropion of the left eye causing conjunctival injection and epiphora(b) Release of the ectropion and tissue deficiency replaced by a full-thickness skin graft,(c) Result at four months after operation.

Flaps and free tissue transfer

In certain instances, the area in need of reconstructionmay lack the vascularity to support the skin graft,e.g., bare tendon, bone, cartilage, and ischaemicwounds. There are also occasions when a skin graftcould theoretically close the defect or correct a de-formity, but is not the most desirable type ofreconstruction. Such is the case when deeper tissue isdesired for contouring or padding over bony promi-nence, future surgery will be necessary beneath thereconstructed area, near-normal sensation is requiredof the reconstructed area, or the hoped-for aestheticresult cannot be achieved by a skin graft. In all thesecircumstances, reconstruction can be better effectedby a skin flap."

In comparison to skin grafts, skin flaps carry agreater bulk of non-contractile, mobile tissue into thearea and shorten the post-operative period of immo-bilization. A good example is the use of latissimusdorsi fasciocutaneous flap as described by Tolhurstand Haeseker.9 Apart from the advantages of flapthinness and pliability common to all fasciocutaneousflaps, it is easy to raise and can reach the axillary fold.It has been considered to be the first-line reconstructiveoption in burn contractures of the axilla.10

Flaps can be transferred with their pedicles stillattached to the donor site or by dividing the vascularpedicle and reanastomosing it in a recipient site as afree flap. Harii and his associates pioneered the use offree tissue transfer for burn wound reconstruction.Ohmori11 reported a large series of free flaps in 1978.With the rapid improvement of microsurgical tech-nique and the understanding of flap physiology, freetissue transfers of composite tissue from distant areasare almost routinely successful.

Free tissue transfer provides a number of advan-tages. It makes possible the transfer of a large freeskin flap of almost any shape or composition in onestage and thereby the hospital stay is greatly short-ened. A second advantage is that tissues that havebeen difficult to transfer, such as muscles and toes,can be transferred under physiologically favourableconditions. The disadvantage of free tissue transferlies chiefly in its technical difficulties and the impor-tance of in-depth training in microvascular surgeryhas to be stressed.

As a result of the reported successes in late recon-struction, surgeons begin to extend the application offree tissue transfer to the management of acute burnwound. It is probably rarely needed as when corticalbone or bare tendon is exposed. However, this occursmore frequently in electrical burns. Wang12 was ableto salvage 60% of the ischaemic limbs when earlyvein grafting was used in the management of electri-cal injuries to the upper extremities. Silverberg13 andhis colleagues have reported the use of free flaps inthe acute wound management following electrical in-jury. They felt that electrically-induced endothelialdamage was not a problem if large vessels outside theimmediate zone of electrical damage were used asrecipient vessels.

Free tissue transfer is invaluable where local tissueis not available because it is included in the area ofinjury. When used judiciously, it should solve manyproblems which previously resulted in limb amputa-tion.

Tissue expansion

Tissue expansion is based on the observation thattissue expands in the biologic conditions of preg-

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Fig. 3. (a) Burn scar of the dorsum of right forearm. A tissue expander is to be inserted under the ventral surface toexpand the unburned skin,

(b) Expansion completed three months later.(c) At the second operation, scar excised except for the dista! part across the wrist joint.(d) Expanded ventral skin advanced to close the defect.

nancy, obesity, and pathologic conditions such as tis-sue overlying neoplasms. In 1957, Neumann describedthe use of a subcutaneously placed implant in anattempt to reconstruct an external ear deformity.Working independently in 1975, Radovan and Austaddeveloped the concept of tissue expansion with asilicone implant.

Most of the information regarding the biology oftissue expansion has been derived from animal ex-periments, since human tissue is difficult to obtain. Itappears that gradual stretching of the skin can occurwithout the risk of cell necrosis and dermal rupture.Epidermal cells and the thickness of the epidermisare essentially unchanged. The dermis thins and thereis an increase in the number of fibroblasts andmyofibroblasts. There is significant thinning of thesubcutaneous tissue and atrophy of muscle whetherthe expander is placed above or below the specificmuscle. None of these changes would seem detri-mental to the use of expanded skin for reconstruction.In fact, Cherry and his associates14 demonstrated adramatic increase in vascularity during tissue expan-sion. Comparing expanded flaps to delayed flaps andacutely raised flaps, they were able to show that flapselevated in expanded tissue had the greatest increasein survival length, averaging 117% over control flaps.

The use of tissue expansion in burn reconstruction

Is not without complications.15, 16 Minor problems wereencountered in 10 to 29% of the patients, but theoriginal goal of the reconstruction was obtained. In12 to 19% of the patients, major complications inter-rupted the planning and the procedure might have tobe abandoned. However, the benefits of a decrease inthe necessity to graft the flap donor site, an increasein the vascularity of the expanded tissue flap, and theprovision of skin of similar colour, texture, thickness,and composition outweigh the risks. In the success-fully managed cases, the results are frequently farsuperior to those made possible with available alter-native techniques (Fig. 3).

Tissue expansion has become the method of choicefor reconstruction of scalp defects.17 It is the only pro-cedure that allows the development of relativelynormal hair-bearing tissue to cover areas of alopecia.Tissue expansion allows closure of large defects in ashorter time than previously required with multipleprocedures and many serial excisions. Another com-mon application of this technique is in the face andneck reconstruction where skin colour and qualitymatch are of particular importance (Fig. 4). Tissueexpansion has also been used to provide a large fullthickness skin graft and allow the donor site to beclosed primarily.18

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Fig. 4. (a) Severe scarring of the chin and submentalregion causing extrinsic perioral contracture.

(b) Neck skin expanded to provide skin with goodquality and color match.

Conclusion

Reconstruction in burned patients is d i f f i cu l t becauseof the intense scarring and the necessity to performmultiple procedures for different reconstructive needsin a single patient. The preoperative assessment,planning of reconstruction and the establishment ofreconstructive priorities are essential for the desiredoutcome. With the modern techniques of skin expan-sion, microvascular tissue transfers, myocutaneousand fasciocutaneous flaps, the treatment of establishedburn contractures could be highly successful.

References

1. Deitch EA, Wheelahan TM, Rose MP, Clothier J, CotterI. Hypertrophic burn scars: analysis of variables. JTrauma 1983; 23: 895-8.

2. Robson MC. Disturbances of wound healing. AnnEmerg Med 1988; 17: 1274-8.

3. Larson DL, Abston S, Evans EB, Dobrkovsky M,Linarees HA. Techniques for decreasing scar forma-tion and contractures in the burned patient. J Trauma1971; 11: 807-23.

4. Kischer CW, Shetlar MR. Collagen and mucopoly-saccharides in the hypertrophic scar. Connect TissueRes 1974; 2: 205-13.

5. Quinn KJ. Silicone gel in scar treatment. Burns InclTherm Inj 1987; 13 (suppl): S33-40.

6. Ahn ST, Monafo WW, Mustoe TA. Topical silicone gel:a new treatment for hypertrophic scars. Surgery 1989;106: 781-6.

7. Robson MC, Barnett RA, Leitch IOW, Hayward PG.Prevention and treatment of postburn scars and con-tracture. World J Surg 1992; 16: 87-96.

8. Koss N. The mathematics of flap design. In: Krizek TJ,Hoopes JE, eds. Symposium on basic science in plasticsurgery. St. Louis: CV Mosby, 1976: 274-83

9. Tolhurst DE, Haeseker B. Fasciocutaneous flaps in theaxi l l a ry region. Br J Plast Surg 1982; 35: 430-5.

10. Achauer BM, Spenler CW, Gold ME. Reconstruction ofaxillary burn contractures with the latissimus dorsifasciocutaneous flap. J Trauma 1988; 28: 211-3.

11. Ohmori K. Application of microvascular free flaps toburn deformities. World j Surg 1978; 2: 193-202.

12. Wang X. Early vascular grafting to prevent upper ex-tremity necrosis after electrical burns. Chin Med J (Engl)1984; 97: 53-6.

13. Silverberg B, Banis JC Jr, Verdi GD, Acland RD.Microvascular reconstruction af ter electrical and deepthermal injury. J Trauma 1986; 26: 128-34

14. Cherry CW, Austad E, Pasyk K, McClatchey K, RohrichR|. Increased survival and vascularity of random-pat-tern skin flaps elevated in controlled, expanded skin.Plast Reconstr Surg 1983; 72: 680-7.

15. Gottlieb LJ, Parsons RW, Krizek TJ. The use of tissueexpansion techniques in burn reconstruction. J BurnCare Rehabil 1986; 7: 234-7.

16. Xang JY. Clinical experience of tissue expansion inburn reconstruction. In: Ohurat, Sugiharat, eds. TheThird International Tissue Expansion Symposium. Ja-pan: Sando Inc., 1991: 318-24.

17. Manders EK, Graham WP III, Schenden MJ, Davis TS.Skin expansion to eliminate large scalp defects. AnnPlast Surg 1984; 12: 305-12.

18. S pence RJ. Experience with novel uses of tissue ex-panders in burn reconstruction of the lace and neck.Ann Plast Surg 1992; 28: 453-64.