Surgery
Treatment of in-transit metastatic melanoma
In-transit melanoma disease on the lower limb
When melanoma spreads, it does so invariably by the lymphatic system which drains to the regional lymph nodes. Uncommonly, melanoma can become trapped in the lymphatic vessels and grow to cause tumour nodules in the skin and subcutaneous tissues between the primary site and the regional lymph node basin.
These nodules are termed in-transit metastases and carry an ominous prognosis.
Treatment options
Local excision
Surgical excision of in-transit nodules of melanoma is recommended if there are only a few. Further crops are likely to evolve in the future in this condition.
Carbon Dioxide Laser Vaporisation
Laser surgery for in-transit melanoma disease
Suitable if there are many tumour nodules and especially if they are superficial rather than deep within the layers of skin. This operation can be performed as a day-case procedure either under local, regional or general anaesthetic. Post-operatively, the wounds are remarkably painless and heal well. Further crusts of tumour can be treated by repeat laser vaporisation.
Isolated limb perfusion
ILP on lower limb, with cannulation of the femoral blood vessels
Using Melphalan and tumour necrosis factor alpha (TNF-Alpha). This is a highly specialised procedure offered in only a few specialist centres. The main artery and vein to a limb (usually the leg) are cannulated, and using a tourniquet to isolate the limb, an extra-corporeal circuit is established using a pump oxygenator.
ILP apparatus: Note the perfusionist controlling the chemotherpy flow
The limb is then warmed by a heater in the circuit and drugs are introduced when the limb temperature rises to about 39°C. This is done to dilate skin capillaries and because hyperthermia potentiates the effects of Melphalan.
A continuous leak-monitoring system is used. When the extra-corporal circuit is stable, a large dose of Melphalan and TNF-Alpha is introduced into the circuit. The dose of drugs used would be fatal if given systemically, thus the isolation of the limb with the tourniquet is vital.
Hyperthermic perfusion is then continued for about two hours before washout and restoration of the normal circulation.