1498
A
Table 37-2
Nyhus classification system
Type I
Type II
Indirect hernia; internal abdominal ring
normal; typically in infants, children,
small adults
B
Indirect hernia; internal ring enlarged
without impingement on the floor of the
inguinal canal; does not extend to the
scrotum
UNIT II
PART II
SPECIFIC CONSIDERATIONS
Type IIIA
Direct hernia; size is not taken into
account
Type IIIB
Indirect hernia that has enlarged enough
to encroach upon the posterior inguinal
wall; indirect sliding or scrotal hernias
are usually placed in this category
because they are commonly associated
with extension to the direct space; also
includes pantaloon hernias
Type IIIC
Femoral hernia
Type IV
Recurrent hernia; modifiers A–D are
sometimes added, which correspond
to indirect, direct, femoral, and mixed,
respectively
C
D
E
F
G
A - Umbilicus
B - Median umbilical ligament
(urachus)
C - Medial umbilical ligament
(obliterated umbilical vein)
D - Lateral umbilical ligament
(inferior epigastric vessels)
E - Lateral fossa (indirect hernia)
F - Medial fossa (direct hernia)
G - Supravesical fossa
Bladder
Figure 37-4. Posterior view of intraperitoneal folds and associated fossa: A. Umbilicus. B. Median umbilical ligament. C. Medial
umbilical ligament (obliterated umbilical vein). D. Lateral umbilical ligament (inferior epigastric vessels). E. Lateral fossa (indirect
hernia). F. Medial fossa (direct hernia). G. Supravesical fossa.
(Modified with permission from Rowe JS Jr, Skandalakis JE, Gray
SW. Multiple bilateral inguinal hernias. Am Surg. 1973;39:269.)
ilioinguinal nerve emerges from the lateral border of the psoas
major and passes obliquely across the quadratus lumborum. At
a point just medial to the anterior superior iliac spine, it pierces
the transversus and internal oblique muscles to enter the inguinal
canal and exits through the superficial inguinal ring. It supplies
somatic sensation to the skin of the upper and medial thigh. In
males, it also innervates the base of the penis and upper scrotum.
In females, it innervates the mons pubis and labium majus. The
iliohypogastric nerve arises from T12–L1. After it pierces the
deep abdominal wall, it courses between the internal oblique and
transversus abdominis, supplying both. It then divides into lateral
and anterior cutaneous branches. A common variant is for the iliohypogastric and ilioinguinal nerves to exit around the superficial
inguinal ring as a single entity. The genitofemoral nerve arises
from L1–L2, courses along the retroperitoneum, and emerges on
the anterior aspect of the psoas. It then divides into genital and
femoral branches. The genital branch enters the inguinal canal
lateral to the inferior epigastric vessels, and it courses ventral to
the iliac vessels and iliopubic tract. In males, it travels through
Umbilicus
Linea alba
Arcuate line
Rectus muscle
Inferior epigastric vessels
Transversus
abdominis
muscle
arch
Superior
anterior
crus
Direct
hernia site
Spermatic cord
Indirect
hernia site
Femoral canal
Deep
inguinal
ring
Iliopubic
tract
Spermatic
vessels
Pubic tubercle
Cooper’s ligament
Obturator
vessels
Figure 37-3. Anatomy of the groin region from the posterior perspective.
External iliac
vessels