Interventional pain treatments for cancer pain.

Cancer pain is prevalent and often multifactorial. For a segment of the cancer pain population, pain control remains inadequate despite full compliance with the WHO analgesic guidelines including use of co-analgesics. The failure to obtain acceptable pain or symptom relief prompted the inclusion of a fourth step to the WHO analgesic ladder, which includes advanced interventional approaches. Interventional pain-relieving therapies can be indispensable allies in the quest for pain reduction among cancer patients suffering from refractory pain. There are a variety of techniques used by interventional pain physicians, which may be grossly divided into modalities affecting the spinal canal (e.g., intrathecal or epidural space), called neuraxial techniques and those that target individual nerves or nerve bundles, termed neurolytic techniques. An array of intrathecal medications are infused into the cerebrospinal fluid in an attempt to relieve refractory cancer pain, reduce disabling adverse effects of systemic analgesics, and promote a higher quality of life. These intrathecal medications include opioids, local anesthetics, clonidine, and ziconotide. Intrathecal and epidural infusions can serve as useful methods of delivering analgesics quickly and safely. Spinal delivery of drugs for the treatment of chronic pain by means of an implantable drug delivery system (IDDS) began in the 1980s. Both intrathecal and epidural neurolysis can be effective in managing intractable cancer-related pain. There are several sites for neurolytic blockade of the sympathetic nervous system for the treatment of cancer pain. The more common sites include the celiac plexus, superior hypogastric plexus, and ganglion impar. Today, interventional pain-relieving approaches should be considered a critical component of a multifaceted therapeutic program of cancer pain relief.