Diagnostic ultrasound ( PDFDrive )

476 PART II Abdominal and Pelvic Sonography
Key to identifying internal inguinal ring =
inferior epigastric artery
1
1
2
2
3
4
FIG. 13.9 Inferior Epigastric Vessels (IEVs) Are Main Landmarks for Evaluating Inguinal Area. Image 1 was obtained in a transverse plane
about halfway between the umbilicus and the pubic symphysis. The inferior epigastric artery and its paired veins lie along the midlateral posterior
surface of the rectus abdominis muscle. Image 2 was obtained several centimeters inferiorly, and the IEVs lie more laterally. Image 3 was obtained
at a level where the IEVs (arrow) lie at the edge of the rectus muscle. This is the level at which most spigelian hernias occur. Once the origin of
the inferior epigastric artery is identiied, the transducer should be rotated into planes that are parallel (see line 4 on the drawing) and perpendicular
(see image 3) to the inguinal canal—long-axis and short-axis views.
3
Long axis and short axis—not longitudinal and transverse
TABLE 13.1 Types of Inguinal Hernias
Hernia Type Key Findings Classic Teaching Point
Indirect inguinal
Direct inguinal
Spigelian
Femoral
Herniated structures enter the inguinal canal lateral
to the epigastric artery and superior to the
inguinal ligament, and extend for a variable
distance through the inguinal canal.
Arise from conjoined tendon, inferior and medial to
inferior epigastric artery. Herniation at the inferior
aspect of Hesselbach triangle.
Arise through the spigelian fascia just lateral to
where it is penetrated by the internal epigastric
artery. The transverse abdominis tendon is
always torn. In most cases the internal oblique
aponeurosis is also torn.
Within the femoral canal, inferior to the inguinal
ligament.
Most common groin hernia.
Extension into scrotum or labia majora is
almost always due to indirect hernia.
Associated with increased abdominal pressure
(ascites, obesity, pregnancy), older age, and
weak musculature
Sonography shows a complex mass within the
anterolateral aspect of the abdominal wall,
which may contain luid- or gas-illed loops
of bowel.
This type of hernia has a relatively high
association with incarceration.
with known disorders of tissue strength, including Ehlers-Danlos,
Marfan, and Hurler-Hunter syndromes, polycystic kidney disease,
and osteogenesis imperfecta, are at increased risk for inguinal
hernia. 14,19-21
Indirect Inguinal Hernias
he characteristic inding of an indirect inguinal hernia is
abnormal movement of intraabdominal contents (fat, bowel, or
both) through the deep inguinal ring and through the inguinal
canal. In the short axis, the indirect inguinal hernia can be seen
moving into and out of the plane adjacent to the spermatic cord
(in males). 1,8,22,23
Indirect inguinal hernias are the most common type of groin
hernia, being ive times more common than direct hernias. 24 In
boys, the indirect inguinal hernia is the result of a congenital
defect of a patent processus vaginalis. In adults, an indirect hernia
is acquired as a result of weakness and dilation of the internal
inguinal ring. 25,26 Indirect hernias represent a persistence of a
patent process vaginalis. In males the testis descends from the
abdominal cavity into the scrotum, which can result in delayed