Analgesic and Sensory Effects of the Pecs Local Anesthetic Block in Patients with Persistent Pain after Breast Cancer Surgery: A Pilot Study.

Background: Persistent pain after breast cancer surgery (PPBCS) develops in 15% to 25% of patients, sometimes years after surgery. Approximately 50% of PPBCS patients have neuropathic pain in the breast, which may be due to dysfunction of the pectoral nerves. The Pecs local anesthetic block proposes to block these nerves and has provided pain relief for patients undergoing breast cancer surgery, but has yet to be evaluated in patients with PPBCS.

Methods: The aim of this pilot study was to examine the effects of the Pecs block on summed pain intensity (SPI) and sensory function (through quantitative sensory testing [QST]) in eight patients with PPBCS. SPI and QST measurements were recorded before and 30 minutes after administration of the Pecs block (20 mL 0.25% bupivacaine). Pain intensity and sleep interference were measured daily before and after the block for 7 days.

Results: Patients experienced analgesia (P = 0.008) and reduced hypoesthesia areas to cold (P = 0.004) and warmth (P = 0.01) after 30 minutes. The reported pain relief (P = 0.02) and reduced sleep interference (P = 0.01) persisted for 7 days after the block.

Conclusions: This pilot study suggests that the pectoral nerves play a role in the maintenance of pain in the breast area in PPBCS and begs for further research.