Ultrasound Blocks for the Anterior Abdominal Wall

3. Transverse Abdominal Plexus Block | 41
An alternative is the subcostal TAPB (Figure 3.7). In this case
the transducer is placed immediately inferior to the costal
margin on the anterior abdominal wall (Hebbard 2008). The
anesthetic can be injected with an in-plane approach. A good
ultrasound landmark may be the TAM plane at the medial edge
of the transverse adbominal muscle, near the border with the
rectus muscle (Figure 6.2)
Figure 3.7 – Subcostal transverse abdominal plexus block.
The rationale for the subcostal TAPB lies in the fact that the
nerves located between the costal margin and the inguinal
ligament at the anterior axillary line have a segmental origin
from T9 to L1. Levels more cranial than this, T6 to T8, are not
covered with the classical TAPB, limiting its usefulness to lower
abdominal surgery. However, a more extensive pattern of nerve
involvement may result if an additional injection is made
anterior-medial to the costal margin (Rozen 2008). The