By HECTOR MARINO, M.D.

Transcription

1 THE LEVELLING EFFECT OF Z-PLASTIES ON LINEAL SCARS OF THE FACE By HECTOR MARINO, M.D. From the Buenos Aires Naval Hospital and the Air Force Central Hospital, Argentina IT is quite common in traumatic and plastic surgery to see straight or curved lineal wounds of the face develop depressed and obvious scars notwithstanding the greatest precautions taken in their suture and post-operative care. In the present paper, and without pretending to exhaust the subject, some procedures will be studied which seem to improve cosmetic results according to our experience. The experienced plastic surgeon readily reaches the conclusion that the evolution of facial scars depends on a number of factors, some of which are little influenced by surgical technique. For instance, it is common knowledge that elderly individuals with thin flexible white skin develop post-operative scars which quickly tend to disappear or, at least, to become less conspicuous. On the other hand, in young subjects with dark thickened skin the reaction is often unfavourable and, in spite of all precautions, the scar can be either depressed or retracted, or even worse, distended, pigmented, hypertrophic, or keloidal. Apart from such individual factors, there are others which directly influence the final results. The first and most important relates to the depth of the wound. When it involves only the epidermal layers, healing can be almost perfect, save for a slight hyperpigmentation or depression, but the lesion of the deeper dermal layer will always leave a more or less apparent blemish. This will be increased if the injuring agent reaches the subcutaneous tissue, and even more so if it involves the muscular layer. It has been said that depressed scars are often caused by careless suturing of the subcutaneous and muscular layers. We believe this to be true within certain limits. Correct union of the anatomical planes is certainly helpful, but we often see a lineal wound repaired with a most painstaking technique ending in the course of time in a noticeable local depression. This can be easily explained: it is a well-known fact that the junction of the dermal, subcutaneous, and muscular layers is achieved by the growth of connective tissue (collagen fibrils). The elasticity of connective tissue is quite different to that of neighbouring skin. Therefore this skin at rest will already show a different appearance to that of scar tissue. But this dissimilarity will noticeably increase as soon as the parts are animated by movements and the unyielding structure is pulled by the muscular forces. This distinction will be even more marked if a hmmatoma, an infection, or simple or keloidal hypertrophy increases the volume of the collagenous wall intervening between the normal borders. On the other hand, classical experiences of Langer (1861, 1862) have shown that by tracing incisions along certain theoretical lines the resulting scars will be less conspicuous. Recent studies made by Rubin (I948), and especially by Kraissl (1951) and Kraissl and Conway (I949), show that the ideal location follows the facial creases, which run perpendicularly to the general direction of contraction of the underlying skin muscles (Fig. I). These lines differ to some extent from the original lines of Langer, which can be explained by the fact that Langer 34

2 L E V E L L I N G EFFECT OF Z - P L A S T I E S ON LINEAL SCARS OF THE FACE 35 experimented on the cadaver--that is he obtained a static picture--while the skin of a living being is submitted to dynamic factors. But even adherence to FIG. I Planning of the lines of incision following the wrinkle lines in order to minimise the scar, according to Kraissl. this rule does not always prevent the depression. In young individuals without facial wrinkles a lineal scar is often depressed even when it closely follows the direction which the skin folds will eventually develop with growth (Fig. 2). Dermatological and surgical means are available to decrease or conceal such depressions by making less noticeable the unevenness of the surface by

3 36 BRITISH JOURNAL OF PLASTIC SURGERY chemical or mechanical thinning of the adjoining skin (escharotics, abrasion). Radium and X-ray therapy also help to increase the flexibility of the cicatricial collagen, so as to approximate its elasticity to that of normal skin. But none of these procedures achieves a complete correction. The fundamentals of this noxious effect have been described by Min-Chyang Ju (1951) who demonstrated experimentally that on sticking a slightly tense rubber band on a thinner rubber sheet the traction of the band produces deformities on the underlying rubber and folds comparable to those seen in the skin adjoining lineal scars. The conditions of this experiment could be applied to those found FIG. 2 Depressed scar unsuccessfully resected and sutured. multiple Z-plasties. Result of excision and in the relation between cicatricial collagen and adjoining normal collagen and elastic fibres. We refer to the original article for the mathematical analysis of the geometric patterns found by this writer. We only wish to quote him when he says : " It is the difference in equilibrium of forces and the difference in the degree of active contraction of the scar under varying tensions that explains why scars parallel to and scars perpendicular to Langer's lines behave differently... The relationship between muscle activity and skin tension is comparable to an accordion plait. The accordion moves to and fro in a longitudinal direction without changing the transverse calibre of the plait... a scar perpendicular to the lines of tension is parallel to the direction of muscle pull and lies in a medium which has changing tensions. Being constantly subjected to the stress and pull, it is unstable and tends to become thickened." Amongst other things this tends to emphasise the importance of rest on the proper evolution of the reparative process. The disturbance of the fibrillar arrangement due to continuous microtrauma (as imposed on the wound by the inevitable movements of the facial skin) would thus be one of the basic causes

4 LEVELLING EFFECT OF Z-PLASTIES ON LINEAL SCARS OF THE FACE 37 of the proliferative reaction of the connective tissue. Such a reaction has its maximal manifestation in the hypertrophic cicatricial bands found crossing the flexion creases of the skin covering principal joints. The same writer also analyses in his paper the favourable effect of Z-plasties, which prevent the thickening and the contraction not only by lengthening but also--which is more important--by changing the direction of the scar tissue in order to lessen the variations of tension due to muscular activity. A striking demonstration of the soundness of the procedure is shown by the fact that once the flaps are undermined, they often spontaneously adopt a transposed position. FIG. 3 Semicircular scar enclosing thickened tissues. Result of Z-plasties and abrasion. This favourable effect is even more apparent with multiple Z-plasties, as already proposed by Morestin in I9I 4 for the treatment of retracting scars of the hand. The problem becomes more complicated with a curved lineal scar. The correspondence with Langer's lines loses its significance as the interplay of changing tension lines makes unavoidable the parasitic effect at least in some parts of the scar. Moreover, in partial or total circumferential scars the enclosed area projects itself over the surrounding plane, whatever precautions we take (Fig. 3). Kazanjian and Converse (1949) ascribe this effect to an impairment of the lymphatic circulation. Other writers assign it to cicatricial hypertrophy ; the fact is that even thinning of the thickened skin is followed by a relapse of the condition. Having been confronted many times with this kind of depressed lineal scar we decided to apply the principles of Min-Chyang Ju by combining excision with the multiple Z-plasties of Morestin. We knew already of satisfactory results published by Covarrubias (1958) of Chile, but to be honest we could not bring ourselves to change a straight or curved line into a broken one. In the event

5 38 BRITISH JOURNAL OF PLASTIC SURGERY of failure, our new scar would have been always longer and more conspicuous. The experience gained in scars in other parts of the body justified first attempts FIGS. 4 and 5 Fig. 4.--Distended scar of the neck which recurred after three excisions, undermining and suture. Permanent healing was obtained by Z-plasties. Fig. 5.--Showing the "levelling effect" of Z-plasties on projecting hypertrophic scars. This patient was also submitted to X-ray therapy. and its further use in the face. It was also shrewdly pointed out to us by Correa Iturraspe that this effect of Z-plasties could be classified in a more general way

6 LEVELLING EFFECT OF Z-PLASTIES ON LINEAL SCARS OF THE FACE 39 This implies a comprehensive principle by which Z-plasties ought to be applied not only to lineal depressed scars but also to distended scars (Fig. 4) and on such projecting bands as are seen after burns around the mouth (Fig. 5)- as a levelling effect. FIG. 6 Multiple facial injuries with a long depressed scar, inter alia, starting at the right angle of the mouth and ending in the temporal region. Result of Z-plasties and abrasion performed after waiting one year. FIG. 7 Circular scar enclosing thickened tissues. Result of Z-plasties. We deem it advisable in adopting this technique to consider the following suggestions. I. It is convenient to wait till the end of the evolution of the scar's connective tissue before performing the Z-plasties in order to avoid unnecessary sacrifice of tissue (Fig. 6).

7 4 BRITISH JOURNAL OF PLASTIC SURGERY 2. We are not yet convinced that multiple Z-plasties are justified in a recent accidental wound. This technique could be instead an excellent adjunct to a R F_ ff 7" Y Fla. 8 Covarrubias' plan for correcting depressed scars by interdigitating the borders of the wound. The shaded area corresponds to scar tissue and skin to be resected. 5 X' ~ O ' e' ~..l. - "' 5' $' FIG. 9 Schematic drawing of Hazrati's plan devised to avoid circulatory deficiencies in the skin flaps of multiple Z-plasties. Shaded areas are to be trimmed to allow for the proper interlocking of the flaps. well-planned surgical incision. The circular accidental wound is often complicated by a circulatory deficiency of the enclosed flap. This is a formal contraindication to the procedure, which will be the best treatment as soon as the wound is completely healed, as suggested by Kazanjian (I949) and by Min-Chyang Ju (I95 I) (Fig. 7).

8 LEVELLING EFFECT OF Z-PLASTIES ON LINEAL SCARS OF THE FACE Multiple Z-plastics are possible only if adjoining tissues are elastic enough, as always occurs in the face. Therefore, save a prolongation of the procedure, no technical difficulties are encountered. It is convenient to keep the branches of the "Z " within I cm. in length for better concealment, but it must be remembered that too small flaps can easily develop ischmmia. FIG. IO Depressed lineal scar of the cheek treated only by skin Z-plasties as removal of the deep-scar tissue could involve section of facial nerve branches. The regular Z-plasty always causes a definite lengthening of the scar, which in this case can be excessive. This can be prevented by appropriate removal of excess skin between each Z-plasty, or by adopting a plan similar to that of Covarrubias (Fig. 8). Hazrati's (I952) plan (Fig. 9) has the advantage of not interfering with Langer's lines whenever possible and of avoiding any ischaemic complications in the flaps. Its only disadvantage is that it retains some of the lengthening effect. 4. Complete removal of the scar tissue in the subcutaneous plane is not always feasible ; nevertheless, our experience shows that its coverage with the Z-flaps considerably lessens its harmful effect (Fig. io). Painstaking suture of the different anatomical planes retains its value, but nothing is gained by interdigitating the borders of the deep layers ; on the contrary, this will add to the fibrosis. Suture should be performed with atraumatic technique and the finest material with few deep retaining stitches. 5- The immediate results are not always satisfactory, but improvement is apparent in the course of time and may even amount to virtual disappearance of the scar. This will be naturally helped by known dermatological treatment, massage, and especially by a judicious abrasion performed after a convenient lapse of time (see Figs. 3 and 6).

9 4 2 BRITISH JOURNAL OF PLASTIC SURGERY SUMMARY Resection and suture combining imbrication of the borders of the wound by small successive Z-plasties is proposed as a useful addition to the treatment of lineal depressed scars of the face. Theoretical reasons, which could explain the favourable results reported, are also discussed. REFERENCES CORREA ITURRASPE~ M. Personal communication. COVARROBIAS, Z. R. (1958). In Borges, A., " Cirugia Plfistica de una Herida Cutfinea," Rev. Confed. med. panamer., 5, I. HAZRATI, E. (1952). Plast. reconstr. Surg., xo, 133. KAZANJIAN~ V. H., and CONVERSE, J. M. (1949). " The Surgical Treatment of Facial Injuries," p. 51. Baltimore : Williams & Wilkins Co. KRAISSL, C. J. (1951). Plast. reeonstr. Surg., 8, I. KRAISSL, C. J., and CONWAY, H. (1949). Surgery, 4, 592. LANGER, K. (1861). S.-B. Akad. Wiss., 44, I9. -- (I862). S.-B. Akad. Wiss., 45, 123. MIN-CHYAIqG JrJ, D. (1951). Plast. reconstr. Surg., 7, 343. MORESTIN, M. H. (1914). Rev. Chir., Paris, 50, I. RuBIN, L. R. (1948). Plast. reconstr. Surg., 3, 147.