Neurolytic Blocks (Cryoablation/ Cryoneurolysis)

Cancer pain often stems from growing tumors and injured tissue. One treatment that may be effective for certain types of cancer pain is a neurolytic Injection or block designed to destroy the nerve fibers transmitting the pain. Neurolytic blocks are appropriate only when the pain is clearly identified as coming from specific nerves. For instance, it works well for pancreatic pain but not for widespread bone pain.The chemical used to deaden the nerve fibers is usually either alcohol or phenol.

Also, applications of focused amounts of heat (radio-frequency lesioning) or cold (cryoablation) may be used.

Studies have reported major pain relief from neurolytic blocks in fifty percent to ninety percent of their cancer patients. The downside of damaging nerves is that the effect may persist only for several months. But for someone with a terminal illness, this can be a lifetime.

Neurolytic blocks can help pain stemming from various regions of the body as well as from internal organs. Intercostal blocks can help quell pain in the chest or abdominal wall, while peripheral blocks halt sensations coming from an arm or leg. These blocks, as with other cancer treatments, involve potential trade-offs.

For instance, a peripheral block for severe leg pain runs the risk of causing paralysis. But if a patient has only a short time to live and is in so much pain that he cannot move, stopping that agony by deadening nerves may be a compassionate trade-off. Neurolytic injections are a viable option when they offer a patient the best chance for dying without pain and without compromising quality of life.

Another technique for shutting off painful nerves is radio-frequency lesioning, which zaps an offending nerve and tissue with heat. The doctor uses a fine probe to reach the aggravating nerve and deliver a focused burst of heat through radio wave frequency. The placement and temperature of the probe control the size of the lesion.

A related technique of the radio-frequency lesioning technique is cryoanalgesia or the freezing of unruly nerves. Cryoanalgesia has been around for centuries. In its crudest form, it involves using cold to numb nerves. Its current, sophisticated form involves freezing and destroying nerves with a needlelike instrument called a cryoprobe. The cryoprobe, like the probe used in radio-frequency lesioning, zeroes in on a single nerve. It incapacitates the nerve with intense cold derived from liquid nitrogen. If you have ever had a wart frozen, you are familiar with the freezing action of liquid nitrogen. Other chemicals, such as solutions of alcohol or phenol, also destroy nerves.Nerve-destroying techniques such as radio frequency, cryoanalgesia, and alcohol usually are reserved for critical cases-patients with serious, if not terminal, illnesses like cancer.