If a keloid is surgically excised, the probability that the resulting scar will develop into a fresh keloid is extremely high, and the more florid the keloid the greater the probability. For this reason surgery of keloids is generally to be avoided.
However, when the scar is hypertrophic
rather than keloid and is bridging a flexure, so that contracture appears to have been a factor in its initiation, correction of the contractural element as part of the excisional treatment seems often to reduce markedly the likelihood of recurrence.
The first line of treatment in the circumscribed
keloid is injection of the highly active steroid, triamcinolone.
This can be dramatically successful with obvious flattening and softening apparent in a matter of days.
Nevertheless, it must be remembered always that triamcinolone is itself an extremely potent drug whose action is not fully understood. Caution in its use is essential. It must be injected into the substance of the keloid, and enough injected to make the whole keloid blanch.
Injection can be repeated weekly. When the keloid has become flat with the surrounding skin, treatment should stop. Further injections will produce local skin and fat, atrophy. Remarkably enough the drug is effective regard-less of whether the keloid is red and ‘fresh’ or white and ‘mature’.
A recent additional form of treatment has come in the form of silicone gel.
The gel is applied to the affected area and held in position by tape. The mode of action is unclear and the rate at which the activity of the keloid subsides varies. The method has the virtue of being non-invasive, which is particularly useful in children, and of having no side-effects.
Although not effective in every case, experience has been that scars which fail to improve with silicone gel tend not to respond to injection of triamcinolone either.
The rate of change in the keloid appears to
depend on the length of time for which the gel is applied. Ideally it should be worn at all times other than when washing or bathing.
Surgical treatment may be justified in managing small, troublesome keloids, especially those arising in the earlobes.
This site is almost impossible to treat with other than steroid injections -even when successful, this can leave an unsightly, pendulous remnant behind. Under these circumstances, excision followed by a small dose of radiation may be effective in removing the keloid and preventing recurrence. Although this technique is by no means successful in every instance, the risk of recurrence is one which many patients are prepared to accept.
In clinical practice, the major problems arise
when the condition complicates burns and degloving injuries, the extent of the keloid change precluding the use of steroids and silicone gel. Quite apart from the appearance of the scarring and the contractural problems so frequently associated with it, the severity of the itch which usually accompanies it causes the patient to scratch the area, often to the extent of producing excoriation and exacerbating the problem generally.
It is in this situation that the application of sustained pressure has had a dramatic effect both in mitigating the itch and in causing the condition to regress, with flattening and softening of the previously raised, indurated areas. The mode of action is not known, but its effectiveness has resulted in the development of garments custom-fitted to the individual patient, so that constant uniform pressure is applied to the areas involved.
These garments are worn continuously until resolution is largely complete, which this may take a year and more. Radiation injury 7 The forms of radiation injury in which the plastic surgeon becomes involved are radiodermatitis and radionecrosis , and the aspects which concern him are the ischaemia of the irradiated
tissues and the association of radiation damage with neoplasia.
Avascularity is stated to increase in severity up to 6 months postirradiation, plateauing thereafter, but the fact that both conditions manifest themselves clinically very much later than this would suggest that the ischaemic process may progress for a much longer period.
Radiodermatitis is most often seen today in the facial skin and scalp, and in skin sites which were used as portals in the process of irradiating deep structures, such as intra-abdominal tumours, thyroid tumours, or regional lymph nodes, usually in the neck.
Radiotherapy was also at one time a standard method of treating such facial conditions as acne, sycosis barbae, or lupus vulgaris, and ringworm of the scalp. Although it may no longer be used in this way, patients are still seen with the problems which have resulted from its use. The type of radiation used did not penetrate deeply, and it is unusual to find the deeper tissues significantly involved.
As a result, the excision required in treating an area of radiodermatitis does not often need to be carried deeply much beyond the skin and der-mis. When there is doubt about how deeply the condition extends, the degree of mobility of the skin is a good guide, mobility indicating absence of deep involvement. The vascularity of the base left when the area of radiodermatitis has been excised will also give a good guide to the form that reconstruction should take, graft or flap.
A free skin graft can generally be expected to take well, provided excision has been carried out to clinically normal well-vascularised tissue, though the defect left following excision of radiodermatitis of the scalp treated 40-50 years ago for ringworm is not usually successfully managed using a split skin graft.
Where the site has been used as a portal the
situation is quite different. The entire block of tissue between the skin and the target site is involved.
This form of radiodermatitis has much in common with radionecrosis, and in time frequently progresses to it.
Radionecrosis which involves the skin implies ulceration and is indicative of much more deeply extending ischaemia. In managing such an ulcer the first need is to establish whether or not the ulcer has a neoplastic com-ponent. Biopsy should be used as routine, and it should be both generous and representative.
A diagnosis of radionecrosis made in the absence
of pathological confirmation should not be accepted.
The surgical problems set by radionecrosis can be of considerable magnitude, both from the point of view of resection and of reconstruction. The tissues involved are woody hard, and when essential structures such as major vessels and nerves lie in the involved field the technical diffi-culties do not require stressing.
Ideally the entire area of involvement should be excised both mar-ginally and in depth as a preliminary to recon-struction, but this may not always be practicable, particularly in terms of depth clearance, because of the involvement of vital structures. Reconstruction of such a defect virtually always requires a flap with the blood supply which it brings with it.
If it has not been possible to resect the radionecrotic area in its entirety, the pedicle of the flap used to reconstruct the defect, with its content of blood vessels, is best left undivided indefinitely. Division of the pedicle in such cir-cumstances, even after a very prolonged period of time, is liable to be followed by necrosis of the flap, but if the zone of avascularity has been completely resected the problem does not arise.
If a free flap has been used it is essential to use donor vessels outwith the area of radiation damage.
The association with neoplasia takes two forms, the tumour either arising de nouo in the
irradiated field, or occurring as continuing growth in a neoplasm treated by radiotherapy. The de nova tumour can appear as a late develop-ment in the tissues which were irradiated, even though the primary condition was neither malig-nant nor had malignant potential.
The tumour can be a carcinoma or sarcoma, and often presents as an ulcer appearing in the area.
The extent of the resection required depends on the clinical problem for which the radio-therapy was used, and the type of radiation. Because of its effects on the local lymphatics, metastasis to the regional nodes is rare, and the local tumour tends to remain circumscribed both marginally and in depth, developing within the irradiated area.
Unless the tumour has been grossly neglected, resection need be little more extensive than that required for the background of radiodermatitis or radionecrosis. Tumour recurrence following radiotherapy presents either as failure to respond to the radia-tion, or as recurrence after apparent cure. It tends to be clinically atypical, frequently masquerad-ing as radionecrotic ulceration.
Diagnosis is not made any easier when, as often happens, radionecrosis and recurrent tumour coexist in a single ulcer. As already emphasised, biopsy is
essential. Detailed consideration of how post-irradiation recurrent tumour should be managed is beyond the scope of this book, except to com-ment that the pattern of behaviour associated with the particular tumour tends to be lost, and the destruction of lymphatic channels by the radiation may result in bizarre metastatic patterns.