The fascia iliaca is the muscle fascia of the iliacus muscle and is continuous with the fascia of the psoas major muscle. Laterally it is attached to the iliac crest
The femoral as well as the lateral femoral cutaneous nerves are located underneath the fascia iliaca
The idea of the fascia iliaca block is to inject a large volume of local anaesthetic midways between the femoral and lateral femoral cutaneous nerves in order to obtain lateral and medial spread that will cover both nerves
Fascia iliaca (green line), fascia lata (cyan line), femoral nerve (magenta arrow), lateral femoral cutaneous nerve (black arrow), femoral branch of genitofemoral nerve (green arrow), iliacus muscle (red asterix), psoas major muscle (red arrow), spread of local anaesthetic (yellow) under the fascia iliaca, needle (red)
Only when a femoral nerve block and/or a lateral femoral cutaneous nerve block is not feasible
The idea of the fascia iliaca compartment block is spread of local anaesthetic under the fascia iliaca in order to reach both the lateral femoral cutaneous nerve and the femoral nerve
On the picture on the right the needle (red) is inserted with the needle tip on the deep side of the transverse abdominis muscle (cyan arrows), after piercing the external (white asterix) and internal (yellow asterixs) abdominal oblique muscles
The local anaesthetic (yellow arrow) is deposited between the transverse abdominis muscle and the transversalis fascia (magenta line) which is loosely attached to the muscle
The local anaesthetic spreads across the aponeurosis and covers the deep side of the quadratus lumborum muscle (red asterix), where the subcostal and iliohypogastric nerves run across before the lateral cutaneous branches branch off
Fascia transversalis (magenta line), transverse abdominis muscle (cyan arrows), internal and external abdominis muscles (yellow and white asterixs), subcostal nerve (white line), lateral cutaneous branch (magenta arrow), anterior cutaneous branch (blue arrow), erector spinae (cyan asterix), psoas major (green asterix)
The subcostal (SC) and iliohypogastric (IH) nerves originate from the spinal nerve roots of T12 and L1 respectively
They run across the anterior surface of the quadratus lumborum (QL) muscle
They continue laterally and pierce the posterior aponeurotic extension of the transverse abdominis muscle and enter the TAP (transverse abdominis plane = the neurovascular fascial plane between the transverse abdominis and internal abdominal oblique muscles)
The lateral cutaneous branches of the two nerves branch off typically before entering the TAP, and these lateral branches are not covered by a classical TAP block
The lateral cutaneous branches of the two nerves innervate the iliac crest and the skin of the upper thigh between the iliac crest and the greater trochanter
The needle penetrates the external and internal abdominal obliques and the posterior tail of the transversus abdominis in order to place the needle tip on the anterior side of the aponeurotic posterior extension of the tranverse abdominis that connects to the quadratus lumborum
When local anaesthetic is injected in this position it spreads across the aponeurosis to cover the anterior side of the quadratus lumborum where it blocks the subcostal and iliohypogastric nerves before the lateral cutaneous branches branch off
Needle (red), transverse abdominis (cyan asterix), internal and external abdominal obliques (green and yellow asterixs), quadratus lumborum (red asterix), retroperitoneal fat (magenta asterix), transversalis fascia (blue arrows)
Select a high-frequency linear probe or a curved array probe and place it in the axial plane just proximal to the iliac crest
Identify the three layers of abdominal muscles and slide the probe posterior until you can visualize the posterior aponeurotic extension of the transverse abdominis muscle connecting to the quadratus lumborum muscle (see next page)
Insert the needle from the anterior end of the probe with in-plane technique and advance the needle tip to the fascial plane between the transverse abdominis muscle and the transversalis fascia just anterior to the transverse abdominis aponeurosis
Inject 10 mL of local anaesthetic in this location and it will spread across the aponeurosis and anaesthetize the subcostal and iliohypogastric nerves before the lateral cutaneous branches branch off
The in-plane needle approach to the fascia transversalis plane block
Place the high-frequency linear probe with the medial end just on top of the linea alba
Visualize the linea alba, the rectus abdominis, and the posterior rectus sheath (see next page)
Use color Doppler to identify the epigastric arteries
Advance the needle through the rectus abdominis muscle until the needle tip enters the space between the belly of the muscle and the posterior layer of the rectus sheath
Inject 10 mL of local anaesthetic per side in adults. In children 0.5 mg ropivacaine/kg can be injected per side