Ultrasound Blocks for the Anterior Abdominal Wall

38 | Ultrasound Blocks for the Anterior Abdominal Wall
Figure 3.2 – The abdominal wall visualized from different positions.
Preoperative block administration is recommended as tissue
visualization with ultrasounds may be impaired after surgery
and tissue manipulation. Moreover, late persistence of elevated
local anesthetic levels in the plasma after abdominal blocks have
been shown.
A traditional or classical TAPB may be performed by injecting
the local anesthetic between costal margin and iliac crest at the
mid-axillary or at the anterior axillary line (Figure 3.3, 3.4).
When the transducer is positioned between costal margin and
iliac crest at the mid-axillary or the anterior axillary line, the
three muscular layers of the abdominal wall will be seen on the
screen (Figure 3.2). The EOM, IOM and the TAM are seen as
hypo-echoic longitudinal bands (Figure 3.5). The IOM is the
thickest and the TAM is the deepest. Muscular fascias between
the muscles are seen as hyper-echoic and hyper-lucent.