Limb perfusion

Limb perfusion is a medical technique that is used to deliver drugs locally directly to a site of interest. It is commonly used in human medicine for administration of anticancer drugs directly to an arm or leg. It is also used in veterinary medicine to deliver drugs to a site of infection or injury, as well as for the treatment of cancer in dogs. In both cases, a tourniquet is used to reduce blood flow out of the area that is being treated.

Isolated limb perfusion was first introduced into the clinic by American surgeons from New Orleans in the mid-1950s. The main purpose of the isolated limb perfusion technique is to deliver a very high dose of chemotherapy, at elevated temperature, to tumour sites without causing overwhelming systemic damage. (Unfortunately, while these approaches can be useful against solitary or limited metastases, they are - by definition - not systemic and therefore do not treat distributed metastases or micrometastases). The flow of blood to and from the limb is temporarily stopped with a tourniquet, and anticancer drugs are put directly into the blood of the limb. This allows the person to receive a high dose of drugs in the area where the cancer occurred. The temperature is also increased to 42C causing an increased uptake of the drug by the tumor. The combination of high drug dose and high temperature is toxic systemically, thus the isolation of the limb. Blood flow through the limb is typically achieved using an extracorporeal circuit consisting of cannulae, tubing, peristaltic roller pump, heat exchanger, and pressure monitoring/safety devices. Care must be used in handling the drugs and waste material as they are extremely toxic. Among other types of cancer, isolated limb perfusion has been used to treat in transit metastatic melanoma.

In the early 1990s an alternative technique was developed at the Royal Prince Alfred Hospital in Sydney, Australia: isolated limb infusion. This technique is less complex and uses a minimal invasive percutaneous approach to circulatorily isolate a limb.

Limb perfusion is also used in veterinary medicine, where is it usually referred to as regional limb perfusion (RLP). It is most commonly used in large animals, such as horses, cows, small ruminants, and camelids. These species often require large, cost-prohibitive doses of medications to treat systemically. Regional limb perfusion allows drug dose to be reduced while maintaining therapeutic concentrations at the site of interest, thereby reducing the cost of treatment, localizing application, decreasing systemic side effects, and improving efficacy.

...
Wikipedia