Superiority of ultrasound-guided Shamrock lumbar plexus block.

Ultrasound-guided lumbar plexus block (LPB) performed with the Shamrock approach has received much interest since the technique was first described in 2013. The technique is believed to be faster and easier to perform and possibly safer in regards to potential complications compared with other LPBs. In order to outline some favorable characteristics of the Shamrock LPB, we performed an exhaustive search of the current literature; even though it is rather limited. We have related the evidence to our own clinical experience about the block execution. We present a narrative review of the alleged superiority of the ultrasound-guided Shamrock LPB. Our aim was to assess some of the characteristics that we believe differentiate the Shamrock technique from other ultrasound-guided LPB techniques. We present graphical directions about how to carry out the Shamrock block, and we present novel magnetic resonance images illustrating the injectate spread around the lumbar plexus within the intrapsoas compartment after Shamrock guided injection of contrast enhanced local anesthetic. The Shamrock approach is easier, faster and better to visualise the LPB compared to other LPB techniques. The needle trajectory and needle tip location just lateral to the lumbar plexus probably reduces the risk of adverse effects and complications. Ultrasound guided lumbar plexus blockade is an expert technique. The Shamrock technique improves but does not eliminate all the challenges of ultrasound-guided LPB technique.