Download Hernias of the Abdominal Wall: Inguinal Anatomy in the Male

H e r n i a s of the A b d o m i n a l Wall: I n g u i n a l A n a t o m y in t h e Male
Bob Caruthers. CST. PhD
The surgical repair of an inguinal hernia, although one of the
in this discussion. The anterolateral group consists of two mus-
most common of surgical procedures, presents a special chal-
cle groups whose bodies are near the midline and whose fibers
lenge: Groin anatomy remains one of the more difficult topics
are oriented vertically in the standing human: the rectus abdo-
to master for both the entry-level student and the first assistant.
minis and the pyramidalis. The muscle bodies of the other
This article reviews the relevant anatomy of the male groin.
three groups are more lateral, have significantly larger aponeuroses, and have obliquely oriented fibers. These three groups
MAJOR FASClAL AND UGAMENTAL STRUCTURES
contribute the major portion of the fascia1 and ligamental
The abdominal wall contains muscle groups representing two
structures in the groin area.',!.'
broad areas: anterolateral and posterior (see Figure 1). The
posterior muscles, the quadratus lumborum, do not concern us
At the level of the inguinal canal, the layers of the abdominal wall include skin, subcutaneous tissue (Camper's and
aponeurosis (cut edge)
Internal abdominal
(cut and turned down)
Lacunar (Gimbernatk)
ligament
Inguinal (Poupartk) 11ganenr
Cremaster muscle (medial origin)
Cremaster muscle [lateral origin)
Falx inguinalis [conjoined tendon)
Cremaster muscle and fascia
Reflected inguinal ligament
External spermatic fascia (cut)
Figun, 1-Dissection
of rhe anterior ahdominal wall.
Rectus sheath (posterior layerl
,
Rectus abdomlnls muscle
Inferior epigastric vessels
Deep inguinal ring
".,'
\
--
\
-.
, Transversalis fascia (cut away)
,
Antenor-supenor 111acspme
lliopsoas muscle
Hesselbach 'sl triangle
inguinalis (conjoined)
,
Tesricular vessels and genital
branch of genitofmoral
Scarpa's fascia), external oblique fascia,
cremasteric muscle fibers, spermatic
from the upper six ribs course downward
inguinal (Poupart's) ligament. This liga-
obliquely and anteriorly to become the
ment marks, in the groin, the separation
cord structures, the transversus abdominis aponeurosis, the transversalis fas-
external oblique aponeurosis. The
aponeurotic fibers from each side inter-
between the abdominal wall and the
lower limb. Hernias that occur immedi-
cia, preperitoneal tissues, and peri-
lace with fibers from the opposite side
ately above this ligament are considered
toneum.'.'.'
in the linea alba. Fibers of the external
to be in the inguinal area, while hernias
abdominal oblique fuse with fibers from
existing below the ligament are called
the underlying internal abdominal
femoral hernias (see Figures 2 and 3).
EXTERNAL ABDOMINAL OBUQUE
MUSCLE
oblique to form the sheath of the rectus
The external abdominal oblique muscle
abdominis muscle.'.:,'.'
fibers of the inguinal ligament flatten
into a horizontal shelf. These fibers
largest of the anterolateral muscle
INGUINAL LIGAMENT
groups. The muscle body is found later-
In the groin area, a continuation of the
attach to the os pubis, and this continuation of the inguinal ligament is called
ally, having a strong, flat aponeurosis
occurring anteriorly. The external
aponeurosis of the external abdominal
oblique stretches from the pubic tuber-
The spermatic cord, which courses
abdominal oblique muscle arises from
cle to the anterior-superior iliac spine.
through the inguinal canal, rests on the
the lower outside border of the lower
This extension is a rolled-under, inferior
lacunar ligament until it turns to exit
eight ribs. Fibers from the bottom two
margin of the aponeurosis of the exter-
through the superficial inguinal ring.
ribs insert in the iliac crest, while fibers
nal abdominal oblique and is called the
Fibers that continue laterally along the
is the most superficial, thickest, and
26
Fchruarv IYQB
Thm S r r # l o a l T ~ o h n o l o ~ l s t
The more medial of the rolled-under
the lacunar (Gimbernat's) ligament.
anterior border of the superior ramus of
ic fascia and serves as the middle one of
In the upper abdomen, the intemal
the pubis contribute to the pectineal
abdominal oblique aponuerosis splits at
the three covering layers oi the cord
(Cooper's) ligament.'.'.'
the linea sernilunaris, having an anterior
and posterior sheath. In the lower quar-
and testis (see Figure 4).'.'
INTERNAL ABDOMINAL OBLIQUE
MUSCLE
ter of the abdomen, the aponeurosis does
not split, but masses to the midline,
TRANSVERSUS ABDOMlNlS
MUSCLE
The intemal abdominal oblique mus-
anterior to the rectus abdominis muscle.
The transversus abdominis muscle is the
cle-as
The lower fibers arch over the spermatic
cord and insert in the superior border of
innermost of the flat muscles of the
abdomen, having an extensive and var-
sheet arising from the posterior layer of
the pubis. These fibers join with similar
ied origin in the cartilages of the six
the thoracolumbar fascia, the anterior
fibers from the transversalis tnuscle to
lower ribs, the thoracolumbar fascia, the
two-thirds of the iliac crest, the lateral
form the falx inguinalis.'.','
iliac crest, and the inguinal ligament.
the middle one of the three flat
abdominal muscles-is
a thin, muscular
The internal surface of the muscle is
two-thirds of the inguinal ligament, and
the iliacus fascia. Posterior fibers ascend
vertically to the inferior borders of the
lower 3 or 4 ribs, while the other fibers
lined by the tranversalis fascia.'.:.'
CRENlASLlR MUSCLE AND
FASCIA
The cremaster muscle originates from
TRANSVERSAUS FASCIA
spread fan-like in a forward and medial
the inferior margin of the intemal
The endoabdominal fascia forms a con-
fashion. The ultimate insertion of these
abdominal oblique muscle and forms
part of the coverings of the cord and
tinuous lining of the abdominal cavity.
When this fascia lies deep to the trans-
testis: It underlies the external spermat-
versus abdominis muscle. it is labeled
fibers is the linea alba and the pubic
bone.
Inferior epigastric vessels /covered by transversalis fascia)
Linea alba
External abdominal oblique muscle
/
Aponeurosis of external
abdominal oblique muscle
Transversalis fascia (site of
direct inguinal hernia)
Falx inguinalis (conjohed tendon)
Trarlsveaus abdominis muscle
Crenlaster muscle (medial origin)
Cremaster muscle (lateral origin)
lntercrural fibers
Inguina! iPoupart's)ligament
~xternalspermatic fascia on
spermatic cord exiting
Lacunar IGimbernark) ligament
Superficial inguinal ring
Pectineal (Cooperk) ligament
'
I
Reflected inguinal ligament /
Superficial inguinal ring
Lateral crus
Figure 3-Dissecrton
of the ~nguinalregion (anrerior vtew).
"transversalis fascia." When the
canal is the deep inguinal ring found
endoabdominal fascia is incact, no her-
above the midpoint of the inguinal liga-
lacunar ligaments; the posterior wallsometimes called the "floorn-is formed
nia exists; therefore, all hernias in the
ment. The deep inguinal ring is not
by the transversalis fascia and transver-
groin represent a defect in the transver-
truly "ring-like," but a finger-like diver-
sus abdominis muscle.
salis fascia. This fascia is attached to the
ticulum of the transversalis fascia. The
iliac crest and descends upon the iliac
canal is directed lateral to medial, deep
inguinal canal include the vas deferens;
fascia, serving as the superior fascia of
to superficial, and cephalad to caudad,
deferential artery and vein; testicular
the pelvic diaphragm. The internal
exiting at the superficial inguinal ring
artery; lymphatics; autonomic nerves;
spermatic fascia is the principle out-
occurring above and lateral to the pubic
the ilioinguinal nerve and genital por-
pouching of the transversalis fascia; its
tubercle.
tion of the genitofemoral nerve; and the
mouth is the deep inguinal ring.".'
In the male, the contents of the
cremaster artery, which is a branch of
Whereas the superficial boundary of
the canal is formed by the external
the inferior epigastric artery.'".'.'
INGUINAL CANAL
oblique aponeurosis, the most cephalad
The inguinal canal is approximately
wall is formed by the intemal oblique
INFERIOR EPIGASTRIC VESSELS
4-cm long and obliquely oriented; it lies
and tranversus muscles, along with
The external iliac arteries supply blood
2 cm to 4 cm above and parallel to the
aponeurotic fibers from each. The infe-
to the legs, and the intemal iliac arteries
inguinal ligament. Entrance to the
rior wall is formed by the inguinal and
supply the pelvis and perineum. The
Ductus (vasl deferens covered by peritoneum
Erternal iliac vessels covered by peritoneum
Internal abdominal oblique muscle
\
Ductus (vas) deferens
External abdominal oblique muscle
Inferior epigastric vessels
Transversus abdominis muscle
Cremasteric vessels
Transversalis fascia
Medial umbilical ligament
(obliterated umbilical artery)
Rectus abdominis mcacle
Internal spermatic fascia
Superficial inguinal ring
'Spermatic cord
\
External spermatic fascia
enveloping spermatic cord
Cremaster muscle and
fascia on sperrnaric cord
/
/
\:::
.
.
-
.
Figure 4-Spemur~c cord and ~ngulnalcanal
28
F e b r u ~ r \ I"*S
Tho S u r g i c a l T o o h n o i o g i s t
\
I
Femoral vessels
Inguinal (Poupartk) ligament
External abdominal
Rectus shearh (anterior layer)
External abdominal
Superficial epigastric vessels
Anterior-super~oriliac spine
Intercrural fibers
Inguinal (Poupartk) ligament
ring
Figure &Femoral
and inguinal regions (subcutaneous fascia has been removed).
The techniques of hernia repair are
external iliac artery passes under the
INGUlNAL HERNIAS
inguinal ligament at a point midway
Several schemes are used to describe her-
beyond the scope of this review, but the
between the anterior-superior iliac spine
nias: One of the more traditional distinc-
certified surgical technologist will recog-
and the symphysis pubis: At that cross-
tions made when referring to inguinal
nize that the various methods of repair
ing point, it becomes the femoral artery.
hernias is that between direct and indirect
tend to make use of different ligaments
The external iliac artery follows the
hernias. The indirect inguinal hernia is
to reconstruct an intact and sufficiently
medial border of the psoas muscle, giv-
characterized by a herniation of abdomi-
strong transversalis fascia1 plane.12.'"
ing off several branches. The inferior
nal contents into an unobliterated vagi-
epigastric artery branches from the
nal process within the coverings of the
REFERENCES
external iliac artery just above the
spermatic cord that begins at the deep
1. Woodburne RT, Burke1 WE.
inguinal ligament and has its origin at
inguinal ring. The structures traverse the
Essentials of Human Anatomy. 8th ed.
the medial border of the deep inguinal
inguinal canal to emerge at the superfi-
New York, NY: Oxford University
ring. The spermatic cord passes behind
cial inguinal ring, and the contents may
and lateral to the epigastric artery and
descend into the scrotum (see Figure 5).
The direct inguinal hernia, which
vein.
Press, 1988.
2. Wantz GE. Open Repuir of Hernias of
the Abdominal Wall.Scientific
occurs one-third as frequently as the
American CD-ROM. Scientific
epigastric artery and vein, the symphysis
indirect hernia, develops secondarily to a
American Inc, 1997.
~ u b i sa, nd the rectus abdominis muscle
weakness in the superficial inguinal ring
By using three points-the
inferior
as it reaches the midline of the
and the abdominal wall lateral to the
abdomen-one can create an imaginary
falx inguinalis. The inferior epigastric
triangle called "Hesselbach's triangle,"
artery lies lateral to the mass; that is to
3. Netter E A Guide to the interactive
Atlas of Human Anatomy. Summit,
NJ: Ciba-Geigy Corporation, 1995.
4. Sabiston DC. Textbook of Surgery:
which is used to determine whether a
say, the mass occurs in Hesselbach's tri-
The Biological Basis of Modem Surgical
hernia is considered direct or indi-
angle. The covering layers of this type of
Practice. Philadelphia, Pa: W.B.
rect. I.'.'
hernia are those of the abdominal wall.
Saunders Co, 1997. A