External oblique intercostal (EOI) block for enhanced recovery after liver surgery: a case series

We report our clinical experience with the external oblique intercostal block in three consecutive adult patients who underwent liver surgery for resection of metastases. Enhanced recovery guidelines for liver surgery recommend intrathecal opioids and peripheral regional anaesthetic techniques in the context of multimodal analgesia to achieve adequate postoperative analgesia and early functional recovery. However, both laparoscopic and open approaches to liver surgery involve incisions in the upper abdomen, an anatomical area not well covered by previously described peripheral regional anaesthetic techniques. The external oblique intercostal block is a novel motor- and opioid-sparing technique which blocks both the anterior and lateral cutaneous branches of the thoracoabdominal nerves which innervate the upper abdominal quadrant. In all cases in this series, we performed the blocks in a short period of time and without complications. All patients remained pain- and opioid-free in the postoperative period and achieved enhanced recovery outcomes early. We found the external oblique intercostal block to be a simple, convenient, effective and opioid-sparing regional anaesthetic technique for postoperative analgesia after liver surgery. By minimising opioid use and by obviating the need for central neuraxial anaesthesia techniques in the postoperative period, this block could be incorporated into enhanced recovery protocols for hepatobiliary surgery.