Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
Quadratus Lumborum Blocks
Clinical Anatomy/Sonoanatomy
The quadratus lumborum (QL) is a posterior abdominal wall muscle that lies dorsolateral to the psoas major (PM) muscle. The QL muscle originates from the inner lip of the medial half of the iliac crest and inserts into the lower medial border of the last rib (usually the 12th rib). The medial border of the QL muscle attaches to the transverse processes of the lumbar vertebrae, and its lateral border is free and angled from craniomedial to caudolateral.
The QL muscle is separated from the surrounding muscles by thick fibrous thoracolumbar fascia (TLF). The transversalis fascia (TF) covers the transversus abdominis muscle and continues posteromedially, covering the anterior side of the investing fascia of both the QL and PM muscles.
The three-layer model of TLF comprises anterior, middle, and posterior layers. The QL muscle is located anterior to the middle layer, which is separated from the psoas by the anterior layer of the TF. The posterior and middle layers of the TLF fuse laterally to form the lateral raphe, which is the interwoven connective tissue where the transversus abdominis and internal oblique muscles take their origin (the posterior aponeurotic attachment). The middle layer of the TLF is multilayered (the intermuscular septum where muscles fuse) and medially attaches to the transverse processes of the vertebra.
The subcostal and iliohypogastric nerves pass over the anterior surface of the QL muscle.
Nomenclature and Points of Injection
Quadratus lumborum blocks (QLB) potentially block both the anterior and the lateral branches of the thoracoabdominal nerves. There is more than one approach described under the umbrella term of QLB ( Table 60.1 ). The various QL blocks injection sites are illustrated in Fig. 60.6 .
TABLE 60.1
Main Features of Quadratus Lumborum Blocks
| QL Lateral (Type 1) | QL Posterior (Type 2) | QL Anterior (Transmuscular) | |
|---|---|---|---|
| Clinical Indications | Abdominal surgery either above or below the umbilicus (any type of operation that requires intra-abdominal visceral pain coverage and abdominal wall incisions as high as T6) | ||
| Dermatomes Covered | T6 to T12–L1; blocks the anterior and the lateral cutaneous branches of the nerves | ||
| Lower Extremity Weakness | Not reported | Not reported | Potential |
| Spread to Lumbar Plexus | Not reported | Not reported | Potential |
| Potential Complications | Complications are related to the lack of anatomical understanding and needle expertise. It is possible to puncture intra-abdominal structures such as kidney, liver, and spleen. Bleeding | ||
| Catheter Stability | Stable | Stable | Very stable |
| Injection Site | Lateral to QL muscle, anterolateral border of the QL muscle, at the junction with the transversalis fascia, within the anterior layer of the TLF, anterior to the posterior aponeurotic attachment of the transversus abdominis and internal oblique muscles | Posterior to the QL muscle, within the middle layer of the TLF | Anterior to the QL muscle, between the QL and the psoas major muscles, within the anterior layer of the TLF, close to the tip of the transverse process |
| Level of Difficulty | Intermediate | Intermediate | Advanced |
QL , Quadratus lumborum; TLF , thoracolumbar fascia.
1-Lateral Quadratus Lumborum (QLB1)
The needle can be directed from anterior to posterior toward the junction of the tapered transversus abdominis muscle and the QL muscle; local anesthetic will then be deposited in the lateral border of the QL muscle at the junction with the TF, superficial to the anterior layer of the TLF, and penetrate the aponeurotic attachment of the transversus abdominis muscle (the potential space medial to the abdominal wall muscles and anterolateral to the QL muscle). This block technique is coined QLB1.
You're Reading a Preview
Become a Clinical Tree membership for Full access and enjoy Unlimited articles
If you are a member. Log in here