A randomized comparison between subepineural and conventional ultrasound-guided popliteal sciatic nerve block

Area of Science:

• Anesthesiology
• Regional Anesthesia
• Ultrasound-Guided Procedures

Background:

• Prospective, randomized, observer-blinded trial comparing two sciatic nerve block techniques.
• Investigated subepineural injection at the neural bifurcation (SUB) versus separate post-bifurcation injections.

Purpose of the Study:

• To compare the efficacy and efficiency of a single subepineural sciatic injection versus separate injections for lower extremity anesthesia.
• To evaluate success rate, onset time, performance time, and adverse events.

Main Methods:

• Ultrasound-guided posterior popliteal sciatic nerve block in 50 patients.
• SUB group: single injection within the common epineural sheath at the bifurcation.
• Control group: divided local anesthetic volume injected around tibial and peroneal nerves post-bifurcation.

Main Results:

• The SUB group demonstrated a significantly higher success rate (84% vs. 56%, P=0.032).
• SUB technique led to improved efficiency: decreased performance, onset, and total anesthesia-related times, with fewer needle passes (P≤0.028).
• No neural swelling observed in the SUB group; swelling occurred in 3 patients receiving separate injections.

Conclusions:

• A single subepineural injection at the sciatic nerve bifurcation is more effective and efficient than separate injections.
• The subepineural technique offers reduced procedure and onset times.
• Further research is needed to confirm the safety profile of the subepineural approach.