Critical Evaluation of Chemical Neurolysis of the Sympathetic Axis for Cancer Pain

BACKGROUND: Patients with pain caused by cancer frequently experience visceral pain. In addition to oral pharmacologic therapy to manage pain, neurolytic blocks of the sympathetic axis are also effective in controlling visceral cancer pain. METHODS: Four types of neurolytic blocks (interpleural phenol, celiac plexus, superior hypogastric plexus, and ganglion impar) used in the treatment of visceral cancer pain are reviewed. RESULTS: Several studies have documented the efficacy of neurolytic blocks in reducing pain intensity and opioid consumption. However, the narrow risk-benefit ratio associated with neurolysis techniques requires knowledge of the implications associated with the different neurolytic blocks to minimize undesirable effects. CONCLUSIONS: Neurolysis of the sympathetic axis has been shown to be an effective and safe approach to treat visceral pain in cancer patients and should be incorporated in the armamentarium of the pain specialist as a useful adjunct to oral pharmacologic therapy.