Transversus abdominis plane neurolysis with phenol in abdominal wall cancer pain palliation

Pain is commonly perceived by patients during cancer and its treatment. Although most patients respond to conservative management implemented according to the World Health Organization guidelines, a subset of patients with advanced disease develop intractable pain that may require additional interventions such as regional blocks and intrathecal therapy. Patients with terminal abdominal or pelvic cancer who have high tumor burdens are often offered a diagnostic visceral nerve block followed by neurolysis for pain palliation. Conventional visceral blocks usually require fluoroscopic guidance for correct needle placement in the vicinity of the neuroaxis or abdominal cavity. These techniques carry risks of injury to vessels, bowels, and nerves. Transversus abdominis plane (TAP) block is a technique that is easy to perform (particularly when ultrasonographic guidance is used), has a good safety record, and effectively reduces pain levels and opioid requirements after abdominal and gynecological surgery. Although numerous studies have demonstrated the effectiveness of TAP blocks in acute pain management, the role of TAP block in chronic pain management is very limited. We believe that chemical neurolysis with phenol can prolong the effects of analgesia in patients with terminal cancer. We describe a case of terminal abdominal sarcoma with intractable pain that responded well to a TAP block followed by TAP neurolysis. The patient tolerated the procedure well and demonstrated sustained analgesia for 45 days before dying of the disease. We also demonstrated that TAP block significantly reduces the total opioid requirement as demonstrated by the morphine equivalent daily dose score after the neurolytic procedure. This result supports our belief that TAP block with TAP neurolysis is an effective and inexpensive modality that can be used to palliate intractable abdominal wall pain in patients with terminal abdominal cancer.