High-Definition Ultrasound Imaging Defines the Paraneural Sheath and the Fascial Compartments Surrounding the Sciatic Nerve at the Popliteal Fossa

Abstract

We have demonstrated the paraneural sheath and the fascial compartments, that is, the "subepimyseal perineural compartment" and the "subparaneural compartment" that surround the sciatic nerve and act as conduits for local anesthetic spread during a popliteal SNB.

Combined Saphenous-Sciatic Nerve Blockade Superior to Femoral-Sciatic Nerve Blockade for Postoperative Analgesia Following Foot and Ankle Surgery

“…All groups for both genders that received SS nerve blockade had reduced opioid dosage requirements for breakthrough pain in PACU and this was statistically significant for opioid naïve males. The observed improved analgesia is similar to the report of complete absence of pain in 77% of patients receiving saphenous nerve blockade for lower extremity surgery [22]. Combined sciatic and femoral nerve blockade has been observed to produce slightly lower analgesic efficacy compared to sciatic nerve blockade alone for lower extremity surgery however targeted blockade of the saphenous component of the femoral nerve and its influence on postoperative pain control were not evaluated [23].…”

Comparison of Time Development of the Sciatic Nerve Blockade Performed with 1% Lidocaine Subgluteal and Popliteal Approach under Ultrasound Guidance

“…Although in this paper the introduction of anesthetic subparaneuraly ("subepimyseal perineural compartment") is not discussed, it is described in other studies [15].…”

“…It should be noted that the solution of local anesthetic extends only along each nerve and extends along the entire circumference of each of them. These images display that the solution of local anesthetic is spread in the paraneural sheath which corresponds to the data provided by M. K. Karmakar et al [15].…”

“…We used the introduction of local anesthetic under the common epineural sheath. According to the data of Karmakar M. K. et al the paraneural sheath was distinct from the epineurium, better delineated after the injection of local anesthetic, and enveloped not only the sciatic nerve but also the common peroneal and tibial nerves separately [15]. Figure 1 depicts the sciatic nerve in the popliteal fossa after administration of 30 ml of local anesthetic.…”

“…Considering that the most effective blockade of the sciatic nerve in popliteal area [10] and subgluteal area [11] is reached in the propagation of local anesthetic along the entire circumference of the sciatic nerve, under the control of ultrasound imaging, if necessary, correction of the position of the injection needle to spread local anesthetic solution along the entire circumference of the sciatic nerve was carried out. An important factor for the time of closure of the popliteal sciatic nerve is the place of local anesthetic solution access (extrapareneural, intraparaneural, intraepinerual) [12]- [15]. We used the introduction of local anesthetic under the common epineural sheath.…”