US Pattern Recognition:

abdominal wall

This presentation covers the anatomy of the abdominal wall, and the ultrasound

appearances as relevant to the rectus sheath, transversus abdominal plane and

ilioinguinal blocks.ilioinguinal blocks.

Anatomy

T10

Caudad

Cephalad

Rectus muscle

Linea alba

Semilunaris

Caudad

External oblique

Internal oblique

Transverse abdominis

AnatomyIf the LA is injected between the rectus

muscle and its’ posterior fascia cephalad

and caudad spread occurs. The

intertendinous intersections that form the

“six pack do NOT attach to the posterior

fascia.

skin

Posterior

sheath

Anterior

sheath

muscle

fat

Midline: linea alba

Rectus abdominis

Inf. epigastric vessels

MEDIAL

Peritoneal cavity:

bowel loops

Transversalis fascia/

parietal peritoneum

Sonoanatomy

Right Rectus sheath

Left rectus IP technique, needle

and LA

Ext. oblique

Int. oblique

LATERALTAP

Rectus Trans. abdominis

TAP image, probe over midaxillary line

between costal margin and iliac crest.

TAP IP needle + LA

TAP IP needle + LA

Tips:

• Scan from midline laterally

• Identify known structures

– muscles

– peritoneum– peritoneum

– linea semilunaris

• Determine individual fascial planes

• Nerves lie between internal oblique and

transversus abdominis

• In-plane vs. out-of-plane approaches

EO

IO

Iliohypogastric & ilioinguinal

nervesIlioinguinal

Rectus TA

IliacusFemoral nerve,

not always visible

A

S

I

S

Sonoanatomy Ilioinguinal

M. Weintraud, P. Marhofer, A. Bosenberg, S. Kapral, H. Willschke, M.

Ilioinguinal/Iliohypogastric Blocks in Children: Where Do We Administer the Local Anesthetic Without

Direct Visualization?

Anesth. Analg., January 1, 2008; 106(1): 89 - 93.