Quadratus Lumborum Block for Back Pain Related to Pancreatic Cancer – A Report of Two Cases

Abstract

Pancreatic cancer is often accompanied by severe pain. Patients typically experience upper abdominal and/or thoracolumbar back pain. For those cases failing to respond to standard medical management, as suggested by the World Health Organization, interventions designated at interruption of the sympathetic axis (such as neurolysis of the celiac plexus or splanchnic nerves) have been shown to be efficacious. Other than axial drug delivery, there are few interventional alternatives in patients with pancreatic cancerrelated pain. There is little knowledge regarding the therapeutic effects of treating peripheral somatic soft tissue among oncological patients. Here we report on 2 such patients, whose back pain improved following a quadratus lumborum block. Two patients diagnosed with pancreatic cancer presented with severe back pain. The pain pattern and patients’ physical exams were compatible with myofascial pain arising from the quadratus lumborum muscle, possibly irritated by the abdominal tumor. Advanced pain management, including long- and short-acting opioids and adjuvants, as well as celiac plexus neurolytic block, failed to provide satisfactory pain relief. Given the apparent muscular origin of the pain, a bilateral ultrasound-guided quadratus lumborum block was performed. Four weeks post procedure, the 2 patients reported substantial pain relief supported by reduced consumption of pain medication and improved functional status. No adverse events or complications were observed in either case. In the patients described here, quadratus lumborum block proved to be safe and efficacious in alleviating back pain related to pancreatic cancer. In our opinion, clinicians should be aware of the possible contribution of a myofascial component to pain in pancreatic cancer and in cancer-related pain in general. Key words: Quadratus lumborum block, cancer pain, pancreatic cancer, pain control, myofascial pain syndrome, interventional pain management