Combined sciatic, femoral and obturator nerve blocks for an infra‐inguinal arterial bypass graft surgery

Sir, We have read with interest the article by Asakura et al.1 published in your journal. The authors reported the use of an ultrasound-guided sciatic nerve block, combined with a lumbar plexus block, at the psoas compartment level for emergent infra-inguinal artery bypass graft surgery. This anesthetic technique was reasonable in a patient with systemic vascular disease, anticoagulant therapy and right pyothorax. Very recently, Basagan-Mogol et al.2 described the combination of a psoas compartment and sciatic nerve blocks for a femoro-popliteal bypass surgery in a high-risk patient. Femoral and obturator nerve blockade by the inguinal approach may be a less invasive alternative to lumbar plexus blockade at the psoas compartment level. We have reported a case series of 25 high-risk patients who had combined sciatic, femoral and obturator nerve blocks for an infra-inguinal arterial bypass surgery.3 Femoral and obturator nerve blocks were performed at the inguinal level, using the technique described by Winnie.4 A sciatic nerve block was performed by the classical posterior approach.5 Nerves were localized by a 22-G 100-mm insulated needle (Stimuplex 100 A, Braun, Melsungen, Germany) connected to a peripheral nerve stimulator (Stimuplex). A 40 ml total volume of isobaric bupivacaine 0.375% was injected for nerve blocks. In our reported case series, combined sciatic, femoral and obturator nerve blocks were adequate for surgical procedures and there was no shift from peripheral regional anesthesia to general anesthesia. No patient experienced symptoms or signs of local anesthetic toxicity, nerve injury, hemodynamic instability or hematoma related to regional anesthesia. Post-operatively, there was one case of ventricular tachycardia that responded to cardioversion, two cases of wound infection and one case of graft occlusion that required a new surgical procedure. No perioperative mortality was noted. In conclusion, a sciatic nerve blockade by the posterior approach, combined with femoral and obturator nerve blocks by the inguinal approach, is an alternative to sciatic and lumbar plexus blocks at the psoas compartment level in patients undergoing an infra-inguinal artery bypass graft surgery. We agree with Asakura and colleagues that peripheral regional anesthesia may be a valuable choice for lower-limb revascularization in high-risk patients. Further studies are needed to evaluate the impact of peripheral regional anesthesia on perioperative mortality and morbidity and on vascular graft patency.