Circumpsoas block ... an anterior myofascial plane block for lumbar plexus elements: case report

Abstract

In an attempt to improvise the analgesia in patients with femoral fractures, we aimed at depositing local anesthetic deep to anterior psoas fascia (APf) under ultrasound (US) guidance to block lumbar plexus elements which emerge lateral, anterior, and medial to the psoas major muscle. We termed this as circumpsoas block (CPB). Clinical and computed tomography contrast studies revealed that a continuous CPB infusion with a catheter provided a reliable block of the lumbar plexus elements. No adverse were events noted. We conclude that US guided CPB is a reliable technique for managing postoperative pain after surgery of femur fractures.

Keywords: Acute pain; Femur; Intertrochanteric fracture; Postoperative pai; Regional Anesthesia; Ultrasonography.

Figure 1

A, Placement of ultrasound probe immediately above the inguinal ligament with needle and catheter introduced in-plane; B, Longitudinal ultrasound image depicting the sonoanatomy for CPB, from below upwards are the Pma with the psoas sheath and the iliacus; C, Longitudinal ultrasound image depicting the needle insertion beneath the APf (anterior psoas fascia) in light yellow. LA injection (light blue) lifts the APf and depresses the Pma (light pink); D, Axial view depicting the spread of LA (light blue) around the Pma (light pink) lifting the APf (light yellow).

Figure 2

A, CT contrast spread analysis revealing the spread along the femoral, lateral femoral cutaneous nerve (LFCN), Obturator, genitofemoral (GFN), pudendal, sciatic, the L3, L4, L5, and S1 extraforaminal root level; B, Axial view: contrast spread along the anterior surface of Pma, femoral, LFCN, and obturator pathway. It spreads as far as the upper portion of the obturator internus (OI). Pma, psoas major; GL max-gluteus maximus; C, Axial view: contrast spreads in the posterior surface of the Pma and close to the origin of the 5^th lumbar nerve root, in the neuronal pathway. Pma. psoas major; IC, Iliacus; D, Contrast spread along the medial and lateral borders of Pma that is along the obturator and femoral pathways. Obturator nerve (ON) can be visualized bilaterally at the pelvic brim; E, Catheter extends from the caudal portion of the Pma until it reaches the level of sacroiliac joint at which point it merges with contrast that spreads cephalad on the anterior border, lateral surface, and posterior border of Pma; F. The anterior and posterior surfaces of the Pma are surrounded by contrast in its lower portion. Contrast trickles from the posterior surface and spills in the obturator (ON) pathway onto the superior surface of obturator internus (OI).