A 3-Dimensional Ultrasound Study of Local Anesthetic Spread During Lateral Popliteal Nerve Block

Abstract

Placement of the needle tip beneath the complex fascial sheath of the sciatic nerve resulted in significantly greater perineural local anesthetic volume following a single-injection lateral popliteal approach at the nerve bifurcation and was associated with greater sensory blockade and a characteristic laminar LA spread pattern.

Use of ultrasound for lower extremity

“…Injection under paraneurium allows better diffusion with a greater length of nerve in contact with local anesthetic. The blocks were more effective and had greater success rate than blocks performed outside of the paraneurium layer [14]. In both studies, the authors have shown that it is not an intraneural injection; indeed, no diffusion beyond the epineurium was observed.…”

Three-dimensional ultrasound imaging

“…In an attempt to determine the significance of circumferential local anesthetic spread for nerve block success rate, Marhofer et al Laminar spread pattern is observed after subfascial injection versus a nonlaminar spread pattern after extrafascial injection [5]. The acquired paravertebral volume has been rendered such that the sagittal anatomy is being visualized from the lateral (intercostal space) side.…”

“…Missair et al [5] published the first randomized clinical trial regarding the use of 3-D ultrasound in 2012. Patients were randomized to either receive a subfascial or extrafascial injection during lateral popliteal sciatic nerve block.…”

“…Immediately after each individual injection, a sweep scan of the area of interest was performed. Similar to the process in the study by Missair et al[5], 3-D rendering software was then utilized to generate aSubfascial injectionExtrafascial injectionTransverse (short axis) Longitudinal (long axis) ObliqueTransverse (short axis) Longitudinal (long axis) Oblique…”

Ultrasound and nerve stimulator guided peripheral nerve blocks of the upper and lower limbs

“…intraneuralna -ne preporučuje se i trebalo bi da se izbegava, pogotovo kod blokova perifernih nerava koji su proksimalni, tačnije koji imaju malu količinu vezivnog vlakna i kod kojih na ovaj način nastaje lezija 2. intrapleksus (sub-perineuralna) je tehnika izbora kod poplitealnog bloka. Kada je u pitanju brahijalni pleksus, ova tehnika može da bude ili perineuralna (kada se okružuje svaki pojedinačni nerv) ili perivaskularna (lokalni anestetik se daje u omotač oko arterije) 3. peri-pleksus (ekstrafascijalna) -podrazumeva davanje anestetika van pleksusa, a kada je u pitanju interskalenski blok to bi značilo između skalenskih mišića [17][18][19][20][21][22][23][24][25][26] .…”