Anesthesia and analgesia for cancer-related amputation

Cancer-related amputations, although more and more infrequent, are responsible for a considerable amount of chronic pain that is often resistant to standard therapies and interventions. Cancer patients are particularly at risk of developing the common pain syndromes of phantom limb pain (PLP) and persistent stump pain, secondary to their underlying disease and side effects of the their treatment. A significant number of anesthetic and pharmacologic therapies have been trialed to eliminate these chronic pain conditions. Many techniques, including preemptive epidural analgesia and perineural blockade, have shown promise in eliminating the development of these conditions, but none has been definitively proven superior. Despite the interventions and multiple medications, this group of symptoms remains resistant and continues to drive the search for a panacea. This article reviews studies examining the effect of reducing PLP and persistent stump pain when specific regional anesthesia techniques, such as epidural anesthesia and perineural blocks, are used both preemptively and continued postoperatively. This article also reviews selected trials of pharmacologic therapies for the treatment of chronic postamputation pain in the cancer patient, such as opioids, select N-methyl d-aspartate antagonists, calcitonin, antidepressants, β-blockers, anticonvulsants, and botulinum toxin. Other therapies, such as mirror treatment, use for the alleviation of PLP, are covered as well. The selected key studies reviewed in this article reveal many promising techniques and pharmacologic modalities in the treatment of postamputation cancer pain, yet none has been reliably proven to completely block PLP or persistent stump pain once and for all. Though there have been no dramatic breakthroughs, it is evident that continued research, specifically for cancer patients, is more urgent than ever.