Senior Registrar, Wessex Centre for Plastic and Maxillo-Facial Surgery, Odstock Hospital, Salisbury

Transcription

1 A NEW CLEFT PALATE NEEDLE By M. N. SAAD, F.R.C.S. Senior Registrar, Wessex Centre for Plastic and Maxillo-Facial Surgery, Odstock Hospital, Salisbury AN increasing number of plastic surgeons are abandoning the use of the traditional Jalaguier-Reverdin needle for the repair of cleft palates because : I. Most of these needles are too thick and so are unnecessarily traumatic. 2. In the event of the needles becoming blunt or broken (and as they are fixed to the handles), the whole instrument has to be sent to the manufacturers for repair and this often takes a very long time. 3. The catch and stylette are both delicate and subject to technical failure. A B C E F FIG. I A. Needle passed through the mucosa, with the short end of the suture on the concave side of the needle. B, Loop picked up with dissecting forceps (or a hook) and the end pulled through. C, Needle withdrawn and moved along the suture to the free end. D, Needle passed through the opposite mucosal edge. E, Other end of suture delivered by pulling on the loop. F, Suture tied. Knot on the mucosal side. (Modified from " Cleft Lip and Palate ", by W. G. Holdsworth. London : Heinemann ) 4 E 357

2 358 BRITISH JOURNAL OF PLASTIC SURGERY For these reasons the use of atraumatic sutures is becoming more widespread. While this is probably the most satisfactory technique, there are certain situations where access is difficult and a " Reverdin" type of needle is required. FIG. 2 FIG. 3 Fig. 2.--Curved and semi-curved needles. Fig. 3.--Left : Author's needle. Centre and right : Reverdin needles. With the special technique illustrated in Figure I, it is possible to insert sutures into the nasal layer in the repair of cleft palates without using the catch and stylette, which contribute so much to the bulkiness and cost of the Reverdin needle. The needles illustrated in Figure 2 are simple curved needles with a distal hole, through which 3-0 chromic catgut can be threaded easily. They have no catch and stylette and are much finer than those previously produced (Fig. 3). They are available as curved and semi-curved. The needle portion is screwed on to a handle similar to that of the Kilner skin hook and is therefore " disposable ". This avoids the inconvenience of repair and servicing. These needles were made by Chas. F. Thackray Ltd., Leeds, from whom they are available. I wish to thank my numerous colleagues, and in particular Mr D. 0. Maisels, for their helpful criticism. My thanks are also due to Mr R. Conroy for the photographs and to Mr P. E. Clark for the illustrations.

3 HEALING OF DONOR SITES OF SPLIT SKIN GRAFTS AN EXPERIMENTAL STUDY IN PIGS By C. P. SAWHNEY, M.S. Assistant Professor of Plastic Surgery G. V. SOBBARAJU, M.B.B.S. Resident in Surgery and R. N. CHAKRAVARTI, M.B.B.S., D.T.M.H., D.Phil. Assistant Professor of Experimental Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh IMPORTANT contributions towards the understanding of the healing of donor sites of split skin grafts have been made by Brown and McDowell (I942), Converse and Robb- Smith (1944) and Hinshaw and Miller (1965). However, there remains a gap in our knowledge of the role played by dermis and the changes in its character during healing. It is also important to know whether the thickness of the graft removed has any effect on the course of healing. There is no unanimity of opinion as to the ultimate character of donor sites after healing. Hinshaw and Miller (1965) found donor sites to be identical to normal skin at the end of six weeks whereas Glibin and Sosnovskaya (1967) stated that restitution of the histological structure of the donor site is not complete by that time. In view of the paucity of knowledge on various aspects of healing of donor sites the present study was undertaken. Materials and Methods.--The pig was chosen as the experimental animal because its skin was found to be more suitable for cutting split skin grafts of varying thickness. After shaving, the skin was prepared with the detergent 0. 5 per cent. savlon. Pre- and post-operative antibiotics were given as a routine to ensure healing uncomplicated by sepsis. Animals were premedicated with intramuscular atropine and anmsthetised with Nembutal 20 mg. per kilogram body weight given intraperitoneally or into the ear vein. Supplementary open ether anmsthesia was given for maintenance. The pig skin is 2"6 mm. in thickness. The thick split skin grafts varied from I "4 to i.6 mm. in thickness and thin split skin grafts from o.4 to o'7 mm. in thickness. Twentyfour donor sites have been studied. Experiments were divided into two groups. In one group of 12 experiments thin split skin grafts were taken and in the other similar group thick split skin grafts were taken. Ha:mostasis was ensured by using gauze soaked in i in ioo,ooo adrenaline in saline. The donor sites were covered with a layer of Vaseline gauze and bandaged. Biopsies were taken from the donor sites on days 3, 6, 9, 14, 21, 3, 45 and 6o and the specimens were studied in detail by examining serial sections. The sections were stained with ha:matoxylin and eosin, with Van Gieson stain for collagen, Verhoeff's stain for elastic tissue, Gordon and Sweet's stain for reticulin ai~d alcian blue and PAS stain for studying acid mucopolysaccharides. RESULTS A critical examination of histological sections during the course of healing showed that, besides the process of epithelialisation and regeneration of epidermis, very active

4 360 BRITISH JOURNAL OF PLASTIC SURGERY changes take place in the sub-epithelial zone sandwiched between the regenerating epidermis above and the remaining dermis below. These changes are seen to occur even before the regeneration of the epidermis. For the purpose of description this zone has been designated as the zone of granulation tissue. The sequence and character of changes in the thin and thick split skin graft donor sites were, more or less, similar and therefore they have been described together. Changes in Epidermis.--After three days (Figs. I, 2 and 3) the raw surface is seen to be covered with a crust formed of erythrocytes, leucocytes and fibrin, with a few capillaries which have grown from the dermis. At this time a single layer of basal cells has started growing, mostly from hair follicles but at places from sweat glands and sebaceous glands, and tends to cover the raw surface rather incompletely. The epithelium is seen to grow under the crust. Whereas at most places the epithelium is single-layered, it has grown to muhiple layers close to the source of origin of the epithelium and at such places there was evidence of keratinisation and even an attempt at formation of rete pegs. By the sixth day (Figs. 4 and 5) the crust is seen to have separated completely from the dermis by the development of a newly formed epidermal layer. The epidermis now has a clear basal cell layer and several layers of prickle cells but differentiation into other superficial layers or evidence of keratinisation is not yet clear. The epidermal cells are hyperplastic and hyperchromatic with numerous mitotic figures. On the twenty-first day the epidermis is normal-looking except that the cells are hyperchromatic but after 30 days (Fig. 6) the epidermis looks more or less normal. At the end of 60 days (Fig. 7) the epidermis is 6 to 7 layers thick, is well differentiated into various layers and has fully formed keratin. The basal layers are rich in pigment. The nuclei have lost hyperchromicity and mitotic figures are fewer. It is evident that healing at the donor sites proceeds rapidly and within six days epithelialisation of the donor area is completed, irrespective of the thickness of the split skin graft removed. However, differentiation into various layers of epidermis occurs only after nine days. Changes in the Sub-epidermal Zone of Granulation Tissue.--The earliest evidence of granulation tissue is seen on the third day in the form of multiple, minute, newly formed capillaries and loose connective tissue containing a few fibroblasts and round cells, developing over the whole of the raw surface. On reticulum staining fine thready connective tissue, which is strongly argyrophilic, is seen to form a network entangling the fibroblasts. There is no evidence yet of mucopolysaccharide deposition. On the sixth day (Fig. 8) this zone is intensely oedematous and by the fourteenth day (Figs. 9 and IO) it becomes well defined. It is less vascialar now and thin collagen fibres are seen to form in it. The reticulin fibres have become prominent and there is significant deposition of mucopolysaccharides. After 2I days this zone starts shrinking and is occupied by prominent collagen bundles. After 45 days the zone has shrunk and is seen to be merging with the dermis, but in certain sections it is still well defined. Collagenisation of this zone is marked and deposition of acid mucopolysaccharides is less prominent now. After 6o days the sub-epithelial zone of granulation tissue is fibrous and relatively avascular and parallel bundles of collagen are seen running in the same plane as the epidermis. They are distinct from the dermal collagen which is denser and irregularly disposed. Thus the granulation tissue forms over the resulting raw surface left after taking split skin grafts. This zone enlarges and soon becomes well defined. The regeneration and spread of the epithelium take place over it. This zone shows maximum.activity. There is (a) formation of fibres which in the early stages are argyrophilic but

5 HEALING OF DONOR SITES OF SPLIT SKIN GRAFTS 361 FIG. I FIG. 2 Fig. I.--Section through the donor site of a thin split skin graft on the third post-operative day. The raw surface is covered with epithelium which is single layered in the centre but several layers thick at the periphery of the section. Beneath it are a number of newly grown capillaries; i.e. the earliest evidence of development of granulation tissue. (H & E x IOO.) Fig. 2.--Section through the donor site of a thin split skin graft on the third post-operative day. The newly growing epithelium is seen to arise from basal layers of the contiguous hair follicle. There is a thin zone of granulation tissue underneath. The dermis looks normal. (H & E 40.) FIG. 3 Fig. 3.--Section through the donor site of a thick split skin graft on the third post-operative day. The epithelium is seen growing under the crust and is already a few layers thick ; underneath there is a thin zone of granulation tissue consisting of numerous capillaries. The dermis looks normal. (H & E x ioo.) Fig. 4.--Section through the donor site of a thin split skin graft on the sixth post-operative day. The regeneration of epidermis which has grown to several layers has taken place under the crust which is being lifted up. (H & E x 40.)

6 362 BRITISH JOURNAL OF PLASTIC SURGERY FIG. 5 FIG. 6 Fig. 5.--Section through the donor site of a thin split skin graft on the ninth post-operative day. The epidermis is well differentiated and is hyperplastic with hyperchromatic cells. The zone of granulation tissue underneath is wide and well defined and is composed of numerous capillaries and stellate and spindle-shaped cells embedded in eedematous stroma. (H & E IOO.) Fig. 6.--Section through the donor site of a thin split skin graft after 30 days. The epidermis has assumed, more or less, normal appearance. The zone of granulation tissue underneath shows fibrosis and has started shrinking. (H & E x IOO.) FIG. 7 FIG. 8 Fig. 7.--Section through the donor site of a thick split skin graft on the sixtieth post-operative day. The epidermis is well differentiated and normal looking. The zone of granulation tissue underneath has become thin and contracted and is composed of collagenous tissue. The underlying dermis is normal looking. (H & E X IOO.) Fig. 8.--Section through the donor site of a thick split skin graft on the sixth post-operative day. The epidermis is showing differentiation into various layers and is hyperplastic. It shows formation of fete pegs. The granulation tissue zone underneath is composed of spindle and stellate cells with an oedematous stroma. There are numerous capillaries in it. (H & E IOO.)

7 HEALING OF DONOR SITES OF SPLIT SKIN GRAFTS 363 later become collagen, (b) formation of ground substance rich in mucopolysaccharides to facilitate the binding of collagen fibres into thick bundles and (c) gradual reduction of vascularity and shrinkage as the process of healing progresses, so that after 6o days this zone is represented by a thin layer of well-formed fibrous tissue sandwiched between the epidermis above and the intact dermis below. The rich vascularity in the early phases provides the much needed nutrition to the growing epithelium but with the epidermis becoming normal, the granulation tissue matures and vascularity decreases. FIG. 9 FIG. io Fig. 9.--Section through the donor site of a thick split skin graft on the fourteenth post-operative day. The epidermis is hyperplastic and shows hyperchromasia. The fete pegs are blunt. The zone of granulation tissue is well defined but more fibrous. (H & E IOO.) Fig. io.--section through the donor site of a thin split skin graft on the fourteenth post-operative day. The epidermis is still hyperplastic. The zone of granulation tissue is well defined and underneath it is normallooking dermis. (H & E IOO.) Changes in the Dermis.--The underlying dermis does not show any morphological alterations in the nature of degeneration or regeneration during the course of healing and seems to remain inactive. It, however, provides a base for the formation of granulation tissue. Hinshaw and Miller (I965) had reported that soon after epithelialisation of donor sites, dermal collagen undergoes progressive degeneration and presents appearances simulating granulation tissue but the present study has not been able to confirm these findings as the dermal elements, i.e. collagen and elastic tissue did not show any evidence of degeneration at any stage of healing. Another significant fact brought out by this study is that the healing process both regards time sequence and morphological changes, progresses, more or less similarly, whether a thin split skin graft donor site or a thick split skin graft donor site is healing. These observations are at variance with those of Converse and Robb-Smith (I964) who stated that healing is slower in thick split skin graft donor sites. It is fair to conclude that whereas epidermis regenerates and takes up normal characteristics quickly, the dermis does not regenerate and whatever thickness of dermis is removed with the graft is a net loss. Thus the character of skin'at donor sites as regards its texture, especially in thick split skin graft donor sites, never returns to normal. The zone of granulation tissue does not compensate for this loss of dermis as with the maturation of scar tissue the zone shrinks and is represented by a thin area after 6o days and perhaps would contract to an insignificant dimension stiu later.

8 364 BRITISH JOURNAL OF PLASTIC SURGERY SUMMARY AND CONCLUSION I. The healing process in 24 split skin graft donor sites in pigs has been studied. 2. Epithelialisation of the donor site is complete by the sixth day and the regenerated epidermis becomes fully differentiated and normal looking in 21 to 3o days. 3- A zone of granulation tissue develops soon after removal of the graft and becomes well defined in six days. With passage of time the connective tissue matures and the zone shrinks so that by 6o days the zone is represented by a thin line. 4. Dermis is very inactive and neither degenerates nor shows any evidence of regeneration during the healing process. Thus the portion of the dermis that is removed with the graft is a net loss to the skin. 5. The healing process at the donor site, as regards morphological changes and their time of occurrence, is similar, irrespective of the thickness of the graft removed. REFERENCES BROWN, J. B. and McDOWELL, F. (1942). Ann. Surg. xis, CONVERSE, J. M. and ROBB-SMITH, A. H. T. (1944). Ann. Surg. I2O, 873. GLIBIN, V. N. and SOSNOVSKAYA, T. V. (1967). Acta Chir. plast. 9, 131. HnqSHAW, J. R. and MILLER, E. R. (1965). Archs Surg., Chicago, 91, 658.