If the melanoma is recurrent, confined to a leg or arm, and unable to be surgically removed (unresectable), you may get the chemo medicine by isolated limb perfusion (ILP) or isolated limb infusion (ILI). The goal is to give high doses of chemo to the affected limb (regional chemo) to prevent the side effects experienced from systemic chemo. These approaches may shrink the tumor and help prevent amputation. It may also relieve symptoms, such as pain and swelling. Typically, this therapy is given with general anesthesia in the operating room.
How ILP is done
ILP combines surgery and medicine. First, the surgeon temporarily stops the blood from circulating to and from the affected arm or leg. This stops the high doses of chemo medicine from traveling around the body and affecting other organs.
Then, two small tubes called catheters are put into the limb. One is put in an artery and one is put in a vein. Blood from the vein goes into a machine called a pump-oxygenator. This machine is like the one used in heart bypass surgery. There the blood is mixed with oxygen and chemo medicine. Melphalan is the most common medicine used for this. The blood is then sent to the limb through the artery.
Chemo medicine moves through the limb for up to 90 minutes. During this time, blankets keep the limb warm. The medicines are also warmed as they move through the pump-oxygenator. This may help the chemo work better. At the end of the procedure, the medicines are flushed out of the limb. Normal circulation is resumed. The whole procedure takes about 2 to 3 hours.
ILP and ILI are similar because both involve isolating the limb's blood circulation and forcing fluid containing chemo medicines through the limb. There are several differences between ILP and ILI. With ILI there is no surgical procedure to place the catheters. Instead, the procedure uses a tourniquet to isolate the circulation. This procedure is less complex, shorter in duration, can be repeated, and used in people who are frail and elderly.
How ILP and ILI may help
The main advantage of ILP and ILI is that they let high doses of chemo medicine be given to the affected limb. But they spare the rest of the body from the medicine's side effects. Side effects are mostly limited to the limb, such as limb swelling.
But ILP also has a few drawbacks. For one, it is a major procedure. Also it doesn't affect any cancer that has spread beyond the limb. And while this procedure can often shrink tumors, it may not improve long-term survival better than other treatments.