TRANSSARTORIAL APPROACH FOR SAPHENOUS NERVE BLOCK

Blockade of conduction in the saphenous nerve is important in providin g surgical anaesthesia in the lower leg. Unfortunately, previously des cribed techniques have lacked clinical effectiveness in practice. We d eveloped a transsartorial approach for conduction block of the sapheno us nerve. We first confirmed its potential clinical utility in 12 cada veric specimens by demonstrating that the saphenous nerve was consiste ntly stained by injections of methylene blue. Subsequently, we compare d the relative rates of successful saphenous nerve block and the exten t of conduction block provided by three techniques: (1) transsartorial saphenous nerve block (TSSNB), (2) above knee femoral paracondylar fi eld block (FPFB), and (3) below knee field block (BKFB) of the sapheno us nerve in 20 ASA I volunteers. The transsartorial saphenous nerve bl ock proved to be highly successful (80% success rate) and was superior to the other two approaches in providing cutaneous analgesia to pinpr ick in the saphenous nerve distribution (P < 0.05). The success rates of the BKFB and FPFB were 65% and 40% respectively. A successful block with the transsartorial approach provided complete anaesthesia of the medial malleolus in 94% of subjects whilst the BKFB and FPFB provided complete anaesthesia of the medial malleolus in less than 40% of the successful blocks We recommend the transsartorial approach for more ef fective block of the saphenous nerve.