Fascia Iliaca Compartment Block

Indications and Clinical Considerations

The fascia iliaca compartment approach to lumbar plexus block has the advantage over the Winnie 3-in-1 technique of having a higher success rate than the Winnie technique for blockade of the lateral femoral cutaneous and obturator nerves as well as the femoral branch of the genitofemoral nerve. It also has an advantage over the psoas compartment technique because it is amenable to continuous infusion of local anesthetic by placement of either an 18-gauge intravenous catheter or an over-the-wire central venous catheter into the fascial plane. Lumbar plexus nerve block via the fascia iliaca compartment technique is used primarily for surgical anesthesia of the lower extremity ( Fig. 119.1 ). It is seeing increasing use in the pediatric population. This technique occasionally is used in pain management for treating pain secondary to inflammatory conditions of the lumbar plexus or pain associated with tumor that has invaded the tissues innervated by the lumbar plexus or the plexus itself.

Clinically Relevant Anatomy

The lumbar plexus lies within the substance of the psoas muscle. The plexus is made up of the ventral roots of the first 4 lumbar nerves and, in some patients, a contribution from the twelfth thoracic nerve ( Fig. 119.2 ). The nerves lie in front of the transverse processes of their respective vertebrae; as they course inferolaterally, they divide into a number of peripheral nerves. The ilioinguinal and iliohypogastric nerves are branches of the L1 nerves with an occasional contribution of fibers from T12. The genitofemoral nerve is made up of fibers from L1 and L2. The lateral femoral cutaneous nerve is derived from fibers of L2 and L3. The obturator nerve receives fibers from L2 to L4, and the femoral nerve is made up of fibers from L2 to L4. The pain management specialist should be aware of the considerable interpatient variability in terms of the actual spinal nerves that provide fibers to make up these peripheral branches. This variability means that the findings of differential neural blockade on an anatomic basis must be interpreted with caution. Because these nerves pass anteriorly beneath the inguinal ligament, they are accessible to blockade via the lumbar plexus nerve block technique.

The anatomic basis for using the fascia iliaca compartment plane block is to block the 3 main nerves that compose the lumbar plexus as they lie enclosed by the fascial plane between the quadratus lumborum muscle, the iliacus muscle, and the psoas major muscle ( Fig. 119.3 ). Solutions injected in this fascial plane flow cranially to bathe the lateral femoral cutaneous nerve, the femoral nerve, and the obturator nerve as they pass below the inguinal ligament.