Victor Pauchet, a French surgeon, first described the sciatic nerve block in L’Anesthesie Regionale in 1920: “the site of needle insertion for blocking the sciatic nerve at the level of hip: 3 cm along the perpendicular that bisects a line drawn between the greater trochanter and the posterior superior iliac spine.”1 This technique has since been referred to as “The classic approach of Labat,” possibly because it was first described in the English language literature in 1923 by Gaston Labat, a student of Pauchet, in his book Regional Anesthesia: Its Technic and Clinical Application.2 Labat’s book went through several reprints of the first edition of one of the first English-language textbooks of regional anesthesia. Curiously, this book was very similar to L’Anesthesie Regionale.3 In the same year, Labat founded the American Society of Regional Anesthesia (ASRA). Anecdotally, Labat intended to name the new group “The Labat Society” in his own honor, but the name ASRA remains today as we know it.
Alon Winnie eventually modified the Labat approach in 1975.4 Alternatives, such as the anterior approach described by George Beck in 1963 and the lithotomy approach described by Prithvi Raj in 1975, were devised to allow the sciatic nerve to be blocked in the supine patient.5.6 A number of other approaches have been proposed, most of which include minor modifications. The most useful of these newer techniques are likely the subgluteal and parasacral approach introduced by Pia di Benedetto and Philippe Cuvillon, respectively.7.8 In this chapter, we focus on the classic approach to sciatic nerve block, parasacral and subgluteal modifications, and the anterior approach.
Indications and Contraindications
Indications for sciatic nerve block include lower-limb surgery, combined with a femoral or psoas compartment block.9 For distal surgery of the lower extremity, however, more distal approaches such as ankle block or popliteal sciatic nerve block are preferable whenever feasible. Note that the sciatic nerve block often needs to be combined with additional blocks, such as lumbar plexus (femoral or saphenous nerve) when anesthesia of the entire lower extremity is desired.
Contraindications to sciatic nerve block may include include local infection and bed sores at the site of insertion, coagulopathy, preexisting central or peripheral nervous systems disorders, and allergy to local anesthesia.
The union of the lumbosacral trunk with the first three sacral nerves forms the sacral plexus (Figure 82D–1). The lumbosacral trunk originates from the anastomosis of the last two lumbar nerves with the anterior branch of the first sacral nerve. This structure receives the anterior branches of the second and third sacral nerves, forming the sacral plexus. The sacral plexus is shaped like a triangle pointing toward the sciatic notch, with its base spanning across the anterior sacral foramina. It rests on the anterior aspect of ...