Ultrasound Blocks for the Anterior Abdominal Wall

54 | Ultrasound Blocks for the Anterior Abdominal Wall
Recently an ultrasound and non-selective technique with a
linear 6-13 mHz transducer has been developed for gGNB. Since
it is not possible to achieve gGFN visualization with ultrasounds,
the technique includes the injection of the local anesthetic inside
and outside the spermatic cord (Peng 2008).
The transducer is aligned to visualize the femoral artery in the
long axis and then is moved upwards towards the inguinal
ligament where the femoral artery becomes the external iliac
artery. The spermatic cord is seen superficially to the external
iliac artery just opposite to the internal inguinal ring. It appears
as an oval or circular structure with 1 or 2 arteries (the testicular
artery and the artery to the vas deferens) and the vas deferens as
a tubular structure within it (Peng 2008). The transducer is
moved medially away from the femoral artery and an
out-of-plane technique is used. The final position is about 2
finger-breadths to the side of the pubic tubercle and
perpendicular to the inguinal line.
While with this technique the spermatic cord is likely to be
found outside the inguinal canal, anesthetic infiltration into the
inguinal canal may provide a greater probability of blocking not
only the gGFN, but also the IIN and/or the IHN endings (Rab
2001). Inguinal canal injection would be suitable for inguinal
surgery both in the case of local, general or spinal anesthesia.
An ultrasound-guided gGFB with a 10-18 mHz transducer can
be performed. The transducer is placed under the inguinal
ligament at the intersection between the hemiclavear line and
the line between the pubic tubercle and the ASIS (Figure 5.1).
The femoral artery is visualized transversely along the short axis
(Figure 5.2). Subsequently, the transducer is moved medially
towards the pubic tubercle. The pubic bone is seen as anechoic
(black). The inguinal canal can be seen between the femoral
artery and the pubic bone. It is located more superficial under
the aponeurosis of the EOM as an oval shadow containing the