Hernias
Background
As defined in 1804 by Astley Cooper, a hernia as a protrusion
of any viscus from its proper cavity. The protruded parts are
generally contained in a sac-like structure, formed by the
membrane with which the cavity is naturally lined.1
Since that time, several different types of abdominal wall
hernias have been identified, along with a larger number of
associated
eponyms.
This
article
reviews
the
pathophysiology, evaluation, and treatment of most of these
hernias from an emergency medicine perspective. Hernias
are brought to the attention of an emergency physician
either during a routine physical examination for other
medical complaints or when the patient has developed a
complication associated with the hernia.
Pathophysiology
Types of Hernia - Location
Indirect hernia
An indirect inguinal hernia follows the tract through the
inguinal canal. This results from a persistent process
vaginalis. The inguinal canal begins in the intra-abdominal
cavity at the internal inguinal ring, located approximately
midway between the pubic symphysis and the anterior iliac
spine. The canal courses down along the inguinal ligament to
the external ring, located medial to the inferior epigastric
arteries, subcutaneously and slightly above the pubic
tubercle. Contents of this hernia then follow the tract of the
testicle down into the scrotal sac.
Direct hernia
A direct inguinal hernia usually occurs due to a defect or
weakness in the transversalis fascia area of the Hesselbach
triangle. The triangle is defined inferiorly by the inguinal
ligament, laterally by the inferior epigastric arteries, and
medially by the conjoined tendon.5
Femoral hernia
The femoral hernia follows the tract below the inguinal
ligament through the femoral canal. The canal lies medial to
the femoral vein and lateral to the lacunar (Gimbernat)
ligament. Because femoral hernias protrude through such a
small defined space, they frequently become incarcerated or
strangulated.6
Umbilical hernia
The umbilical hernia occurs through the umbilical
fibromuscular ring, which usually obliterates by 2 years of
age. They are congenital in origin and are repaired if they
persist in children older than age 2-4 years.2,5
Richter hernia
The Richter hernia occurs when only the antimesenteric
border of the bowel herniates through the fascial defect. The
Richter hernia involves only a portion of the circumference of
the bowel. As such, the bowel may not be obstructed, even if
the hernia is incarcerated or strangulated, and the patient
may not present with vomiting. The Richter hernia can occur
with any of the various abdominal hernias and is particularly
dangerous, as a portion of strangulated bowel may be
reduced unknowingly into the abdominal cavity, leading to
perforation and peritonitis.6
Incisional hernia
This iatrogenic hernia occurs in 2-10% of all abdominal
operations secondary to breakdown of the fascial closure of
prior surgery. Even after repair, recurrence rates approach
20-45%.
Spigelian hernia
This rare form of abdominal wall hernia occurs through a
defect in the spigelian fascia, which is defined by the lateral
edge of the rectus muscle at the semilunar line (costal arch to
the pubic tubercle).7,8
Obturator hernia
This hernia passes through the obturator foramen, following
the path of the obturator nerves and muscles. Obturator
hernias occur with a female-to-male ratio of 6:1, because of a
gender-specific larger canal diameter. Because of its
anatomic position, this hernia presents more commonly as a
bowel obstruction than as a protrusion of bowel contents.1
Types of Hernia - Condition
1. Reducible hernia: This term refers to the ability to return
the contents of the hernia into the abdominal cavity,
either spontaneously or manually.
2. Incarcerated hernia: An incarcerated hernia is no longer
reducible. The vascular supply of the bowel is not
compromised. Bowel obstruction is common.
3. Strangulated hernia: A strangulated hernia occurs when
the vascular supply of the bowel is compromised
secondary to incarceration of hernia contents.
Etiology
The embryology of the groin and of testicular descent largely
explains indirect inguinal hernias. An indirect inguinal hernia
is a congenital hernia regardless of the patient's age. It occurs
because of protrusion of an abdominal viscus into an open
processus vaginalis. If the processus contains viscera, it is
called an indirect inguinal hernia. If peritoneal fluid fluxes
between the space and the peritoneum, it is a
communicating hydrocele. If fluid accumulates in the
scrotum or spermatic cord without exchange of fluid with the
peritoneum, it is a noncommunicating scrotal hydrocele or a
hydrocele of the cord. In a girl, fluid accumulation in the
processus vaginalis results in a hydrocele of the canal of
Nuck.
The inguinal canal forms by mesenchyme condensation
around the gubernaculum, which is Latin for rudder because
it guides the testis into the scrotum. During the first
trimester, the gubernaculum extends from the testis to the
labioscrotal fold. The processus vaginalis and its fascial
coverings also form during the first trimester. A bilateral
oblique defect in the abdominal wall develops during the
sixth or seventh week of gestation as the muscular wall
develops around the gubernaculum. The processus vaginalis
protrudes from the peritoneal cavity and lies anteriorly,
laterally, and medially to the gubernaculum by the eighth
week of gestation.
The testis produces many male hormones beginning at the
eighth week of gestation. At the beginning of the seventh
month, the gubernaculum begins a marked swelling
influenced by a nonandrogenic hormone, probably a
mullerian inhibiting substance. This results in expansion of
the inguinal canal and the labioscrotal fold, forming the
scrotum. The genitofemoral nerve also influences migration
of the testis and gubernaculum into the scrotum under
androgenic control. The female inguinal canal and processus
is much less developed than the male equivalent. The inferior
aspect of the gubernaculum is converted to the round
ligament. The craniad part of the female gubernaculum
becomes the ovarian ligament.
Gonads develop on the medial aspect of the mesonephros
during the fifth week of gestation. The kidney then moves
cephalad, leaving the gonad to reside in the pelvis until the
seventh month of gestation. During this time, it retains a
ligamentous attachment to the proximal gubernaculum.
The gonads then migrate along the processus vaginalis, with
the ovary descending into the pelvis and the testis being
enwrapped within the distal processus, known as the tunica
vaginalis. The processus fails to close adequately at birth in
40-50% of boys. Therefore, other factors play a role in the
development of a clinical indirect hernia. A familial tendency
exists, with 11.5% of patients having a family history. The
relative risk of inguinal hernia is 5.8 for brothers of male
cases, 4.3 for brothers of female cases, 3.7 for sisters of male
cases, and 17.8 for sisters of female cases.
Pathophysiology
Inguinal hernias
The pinchcock action of the musculature of the internal ring
during abdominal muscular straining prohibits protrusion of
the intestine into a patent processus. Paralysis or injury to
the muscle can disable the shutter effect. In addition, the
transversus abdominis aponeurosis flattens during tensing,
thus reinforcing the inguinal floor. A congenitally high
position of the aponeurotic arch might preclude the
buttressing effect. Neurapraxic or neurolytic sequelae of
appendectomy or femoral vascular procedures may
contribute to a greater incidence of hernia in these patients.
Repetitive stress as a factor in hernia development is
suggested by clinical presentations. Increased intraabdominal pressure is seen in a variety of disease states and
seems to contribute to hernia formation in these
populations. Elevated intra-abdominal pressure is associated
with chronic cough, ascites, increased peritoneal fluid from
biliary atresia, peritoneal dialysis or ventriculoperitoneal
shunts, intraperitoneal masses or organomegaly, and
obstipation. (See images below.) Other conditions with
increased incidence of inguinal hernias are extrophy of
bladder,
neonatal
intraventricular
hemorrhage,
myelomeningocele, and undescended testes. A high
incidence (16-25%) of inguinal hernias occurs in premature
infants; this incidence is inversely related to weight.
The rectus sheath adjacent to groin hernias is thinner than
normal. The rate of fibroblast proliferation is less than
normal, while the rate of collagenolysis appears increased.
Sailors who developed scurvy had an increased incidence of
hernia. Aberrant collagen states, such as Ehlers-Danlos
syndrome, fetal hydantoin syndrome, Freeman-Sheldon
syndrome, Hunter-Hurler syndrome, Kniest syndrome,
Marfan syndrome, and Morquio syndrome, have increased
rates of hernia formation, as do osteogenesis imperfecta,
pseudo-Hurler polydystrophy, and Scheie syndrome.
Acquired elastase deficiency also can lead to increased hernia
formation. In 1981, Cannon and Read found that increased
serum elastase and decreased alpha1-antitrypsin levels in
people who smoke contribute to an increase in the rate of
hernia in those who smoke heavily. The contribution of
biochemical or metabolic factors in the creation of inguinal
hernia remains speculative.
Umbilical hernias
Umbilical hernias in children are secondary to failure of
closure of the umbilical ring, but only 1 in 10 adults with
umbilical hernias reports a history of this defect as a child.
The adult umbilical hernia occurs through a canal bordered
anteriorly by the linea alba, posteriorly by the umbilical
fascia, and laterally by the rectus sheath. Proof that umbilical
hernias persist from childhood to present as problems in
adults is only hinted at by an increased incidence among
black Americans. Multiparity, increased abdominal pressure,
and a single midline decussation are associated with
umbilical hernias.
Congenital hypothyroidism, fetal hydantoin syndrome,
Freeman-Sheldon
syndrome,
Beckwith-Wiedemann
syndrome, and disorders of collagen and polysaccharide
metabolism (such as Hunter-Hurler syndrome, osteogenesis
imperfecta, and Ehlers-Danlos syndrome), should be
considered as possibilities in children with
Relevant Anatomy
Anterior abdominal wall
The anterior abdominal wall is composed of multilaminar
mirror image muscles, the associated aponeuroses, fasciae,
fat, and skin. Laterally, 3 muscle layers with fascicles run
obliquely in relation to each other. Each inserts into a flat
white tendon, known as an aponeurosis.
The paired rectus abdominis muscles originate on the pubis
inferiorly and insert on the ribs superiorly. The muscle has 4
transversely oriented tendinous bands variably spaced. At
the lateral margin of the rectus abdominis muscles is the
linea semilunaris where the aponeurosis serves as an
insertion for the lateral musculature. The lower edge of the
posterior sheath midway between the umbilicus and the
pubis with its concavity oriented toward the pubis defines
the semicircular line.
Above this line, anterior and posterior laminae form from
division of the internal oblique aponeurosis. The posterior
lamina joins the transversus abdominis aponeurosis and
forms the posterior rectus sheath. The anterior rectus sheath
results from fusion of the anterior lamina and the external
oblique aponeurosis. The external oblique aponeurosis forms
the external lamina of the anterior sheath below the
semicircular line. Fusion of the internal oblique and
transversus abdominis aponeuroses forms the internal
lamina of the anterior sheath. The posterior surface of the
rectus muscles is covered with transversalis fascia below the
semicircular line. The midline linea alba represents a
decussation of these fibers from the different aponeurotic
layers.
The external oblique muscle originates on the lower 8 ribs
with obliquely and inferiorly directed fascicles inserting into
its aponeurosis. Deep to the external oblique muscle is the
internal oblique muscle with obliquely and superiorly
oriented fascicles arising from the iliac fascia deep to the
lateral half of the inguinal ligament, the anterior two thirds of
the iliac crest, and from the lumbodorsal fascia. It inserts into
its aponeurosis, the rectus sheath, and into the lower ribs
and cartilages superiorly.
The transversus abdominis muscle is most internal of the
lateral abdominal wall musculature. The fascicles are
generally transversely oriented. It arises from the lateral
iliopubic tract, from the iliac crest, the lumbodorsal fascia,
and the caudad 6 ribs. It inserts principally into its
aponeurosis and fuses with the internal oblique aponeurosis
to become the posterior rectus sheath. The caudad margin
curves to form the transversus abdominis aponeurotic arch
as the upper edge of the internal ring and above the medial
floor of the inguinal canal. In 3% of cases, this arch may
combine with the internal oblique aponeurosis to form the
conjoined tendon.
The innominate fascia overlies the external oblique muscle.
The transversalis fascia forms an investing fascial envelope of
the abdominal cavity. A variable layer of preperitoneal fat
separates the peritoneum from the transversalis fascia.
Posterolateral (lumbar) region
The quadratus muscle originates from the iliac crest and the
iliolumbar ligament lumborum from between iliac crest and
the fifth lumbar transverse process. It then inserts along the
12th rib. The psoas muscle arises from vertebrae T-12
through L-5 and passes downward under the inguinal
ligament to insert on the lesser trochanter.
The serratus posterior inferior muscle originates from the
lumbodorsal fascia and inserts along the 4 lowest ribs. The
sacrospinalis muscle runs along the spinous processes for the
entire length of the spine.
The latissimus dorsi muscle originates on the posterior third
of the iliac crest, the spinous processes of the sacral and
lumbar vertebrae, and the lumbodorsal fascia. From this wide
origin, the muscle inserts as a tendon into the intertubercular
groove of the humerus.
The superior lumbar triangle of Grynfeltt-Lesshaft is bounded
superiorly by the 12th rib, the posterior lumbocostal
ligament, and the serratus posterior inferior muscle;
inferiorly by the superior border of the internal oblique
muscle; and posteriorly by the lateral border of the
sacrospinalis muscle. The deep margin of the superior lumbar
triangle is the transversus abdominis muscle, and the
superficial margin is the latissimus dorsi muscle. Spontaneous
lumbar hernias occur more commonly because the potential
space is larger and more constant than the inferior lumbar
triangle.
The inferior lumbar triangle of Petit has posterior bounds of
the latissimus dorsi muscle, anterior bounds of the external
oblique muscle, and inferior bounds of the iliac crest.
Inguinal region
Vessels regularly found during inguinal hernia repairs are the
superficial circumflex iliac, superficial epigastric, and external
pudendal arteries that arise from the proximal femoral artery
and course superiorly. The inferior epigastric artery and vein
run medially and craniad in the preperitoneal fat near the
caudad margin of the internal inguinal ring.
The external iliac vessels pass posterior to the inguinal
ligament and iliopubic tract and anterior to the pectineal
ligament to enter the femoral sheath. The external spermatic
artery arises from the inferior epigastric artery just caudad to
the internal inguinal ring to supply the cremaster muscle.
The inguinal ligament bridges the space between the pubic
tubercle and the anterior superior iliac spine to rotate
posteriorly and then superiorly to form a shelving edge. It is
the caudad edge of the external oblique aponeurosis. The
ligament revolves medially to create the lacunar ligament.
The lacunar ligament inserts on the pubis and courses
medially and superiorly toward the midline. The external
oblique aponeurosis has a triangular opening with a superior
apex through which the cord enters the inguinal canal.
The transversus abdominis muscle predominates as a layer of
the abdominal wall for the prevention of inguinal hernias.
The transversus abdominis aponeurotic arch inserts inferiorly
on the Cooper ligament and contributes to the anterior
rectus sheath medially.
The pectineal ligament courses from the superior part of the
superior pubic ramus periosteum. The components
incorporate fibers from the lacunar ligament, the transversus
abdominis aponeurosis, and the pectineus muscle.
An aponeurotic band from the caudad portion of the
transversus abdominis muscle creates the iliopubic tract. It is
the anterior margin of the femoral sheath and the caudad
border of the internal ring. The course is from the superior
pubic ramus medially to the iliopectineal arch and iliopsoas
fascia, anterior to the femoral vessels, and then laterally to
the anterior superior iliac spine.
The iliacus fascia thickens as it exits the pelvis to form the
iliopectineal arch. The fascia curves forward, lateral to the
external iliac vessels, and combines with fibers from the
inguinal ligament, the internal oblique and transversus
abdominis muscles, and from part of the ligament lateral
attachment of the iliopubic tract. The external iliac vessels
pass beneath the inguinal ligament and iliopubic tract but
anterior to the pectineal ligament to enter the femoral
sheath.
The femoral sheath, with contributions from transversalis,
pectineus, psoas, and iliacus fasciae, has 3 compartments. A
femoral hernia most often occurs in the most medial
compartment. The femoral canal is bounded laterally by the
femoral vein. The medial margin is transversus abdominis
aponeurosis insertion and transversalis fascia. The femoral
canal holds lymphatic channels and lymph nodes.
The superolateral border of the Hesselbach triangle is the
inferior epigastric vessels. The inguinal ligament constitutes
the inferolateral side. The lateral edge of the rectus sheath is
the medial side.
The borders of the internal inguinal ring are the transversalis
fascia circumferentially and deep, the arch of the internal
oblique and transversus abdominis muscles superomedially,
and the iliopubic tract inferolaterally. The course of the
spermatic cord or round ligament through the abdominal
wall defines the inguinal canal. Transversus abdominis
aponeurosis and transversalis fascia combine to make the
floor of the inguinal canal in 75% of persons, while a minority
have only transversalis fascia. The external oblique
aponeurosis is anterior, and the inguinal ligament is inferior.
The vas deferens and the testicular artery and vein constitute
the spermatic cord. The innominate fascia extends onto the
cord as the external spermatic fascia. The cremasteric fascia
and the cremaster muscle extend from internal oblique
muscle and its aponeurosis to provide the most external
investment of the cord. The next layer, the internal spermatic
fascia is an extension of the transversalis fascia and contains
the cord structures and tunica vaginalis or an indirect hernial
sac when present.
The inferior epigastric artery, which arises from the external
iliac artery and courses with its companion vein vertically in
the preperitoneal fat, is the anatomical point differentiating
indirect inguinal hernias and direct inguinal hernias. Those
presenting superolateral to the inferior epigastric vessels are
indirect inguinal hernias, while those arising inferomedial to
these vessels are direct inguinal hernias.
The iliohypogastric and ilioinguinal nerves originate
principally from the first lumbar nerve root and have
contributions from the 12th thoracic root. The nerves
traverse the transversus abdominis muscle in the middle of
the iliac crest, are deep to the internal oblique muscle until
the anterior superior iliac spine, and then become superficial
just beneath the external oblique aponeurosis.
The ilioinguinal nerve then runs anterior to the spermatic
cord in the canal to receive sensation from the pubis and the
upper scrotum (labium majus). The genital branch of the
genitofemoral nerve, which arises from the first and second
lumbar nerve roots, becomes superficial near the internal
ring to supply motor fibers of the cremaster muscle and
sensation for the scrotum and medial aspect of the upper
thigh.
The intraperitoneal view has the medial umbilical ligament as
the lateral border of the bladder, and the lateral umbilical
ligament helps to identify the inferior epigastric vessels. The
internal inguinal ring is the apex of a triangle formed medially
by the ductus deferens and laterally by the testicular vessels.
The base of the triangle contains the external iliac vessels,
which may be injured during laparoscopic hernia repair. The
pubic tubercle, the iliopubic tract, the transversus abdominis
muscular arch, the lacunar ligament, the pectineal ligament,
and the lateral border of the rectus abdominis muscle are
usually easily visualized.
The obturator internus muscle arises from the margins of the
obturator foramen and the obturator membrane. The muscle
fascicles exit the pelvis at the lesser sciatic foramen and have
a tendinous insertion on the medial surface of the greater
trochanter of the femur. The obturator vessels and nerve
pass through the obturator canal, which is superior in the
obturator foramen.
The obturator canal runs obliquely in the medial thigh
between the pectineal, external obturator, and long adductor
muscles. The anterior surface of the second through fourth
sacral vertebrae gives rise to the piriformis muscle to have a
tendon traversing the greater sciatic foramen. Above and
below this tendon, in the greater sciatic foramen, are the
suprapiriform and infrapiriform foramens. The superior
gluteal vessels and nerves exit through the suprapiriform
foramen; the sciatic nerve, perineal nerves, and pelvic vessels
pass through the infrapiriform foramen.
Frequency
United States
1. Over 1 million abdominal wall hernia repairs are
performed each year, with inguinal hernia repairs
constituting nearly 770,000 of these cases.9,10,11
2. Approximately 25% of males and 2% of females have
inguinal hernias in their lifetimes; this is the most
common hernia in males and females.11,12
3. Approximately 75% of all hernias occur in the groin; two
thirds of these hernias are indirect and one third direct.2
4. Indirect inguinal hernias are the most common hernias in
both men and women; a right-sided predominance
exists.
5. Incisional and ventral hernias account for 10% of all
hernias.4
6. Only 3% of hernias are femoral hernias.
7.
The incidence of inguinal hernias in children ranges up to
4.4%, while umbilical hernias occur in approximately 1
out of every 6 children.10,2
8. The incidence of incarcerated or strangulated hernias in
pediatric patients is 10-20%; 50% of these occur in
infants younger than 6 months.10
International
Data from developing countries is limited, therefore, an
accurate occurrence value is unavailable. Current
epidemiologic assessments postulate that gender and
anatomic distribution are similar.
Mortality/Morbidity
Morbidity is secondary to missing the diagnosis of the hernia
or complications associated with management of the disease.
1. A hernia can lead to an incarcerated and often
obstructed bowel.
2. The hernia also can lead to strangulated bowel with a
compromised blood supply. Reduced strangulated bowel
leads to persistent ischemia/necrosis with no clinical
improvement. Surgical intervention is required to
prevent further complications such as perforation and
sepsis.
3. Ensuing surgery to repair the hernia or its complications
may leave the patient at risk for infection, future hernias,
or intra-abdominal adhesions.
Race
Umbilical hernias occur 8 times more frequently in black
infants than in white infants.12
Sex
1. Approximately 90% of all inguinal hernia repairs are
performed on males.11
2. Reduction of hernias in females may be complicated by
inclusion of the ovary in the hernia.
3. Femoral hernias (although rare) occur almost exclusively
in women because of the differences in the pelvic
anatomy.
4. The female-to-male ratio of obturator hernias is 6:1. 12
Age
1. Indirect hernias usually present during the first year of
life, but they may not appear until middle or old age.
2. Indirect hernias occur more frequently in premature
infants compared to term infants. Indirect hernias
develop in 13% of infants born before 32 weeks'
gestation.10
3. Direct hernias occur in older patients as a result of
relaxation of abdominal wall musculature and thinning of
the fascia.
4. Umbilical hernias usually occur in infants and reach their
maximal size by the first month of life. Most hernias of
this type close spontaneously by the first year of life,
with only a 2-10% incidence in children older than 1
year.13
Clinical
History
Patients with hernias present to the emergency department
(ED) secondary to a complication associated with the hernia.
Hernias also may be detected in the ED on routine physical
examination. However, in relation to the chief complaint, the
following clinical issues must be considered:
1. Asymptomatic hernia
 Presents as a swelling or fullness at the hernia site
 Aching sensation (radiates into the area of the hernia)
 No true pain or tenderness upon examination
 Enlarges with increasing intra-abdominal pressure
and/or standing
2. Incarcerated hernia
 Painful enlargement of a previous hernia or defect
 Cannot be manipulated (either spontaneously or
manually) through the fascial defect
 Nausea, vomiting, and symptoms of bowel obstruction
(possible)
3. Strangulated hernia
 Symptoms of an incarcerated hernia present combined
with a toxic appearance
 Systemic toxicity secondary to ischemic bowel is possible
 Strangulation is probable if pain and tenderness of an
incarcerated hernia persist after reduction
 Suspect an alternative diagnosis in patients who have a
substantial amount of pain without evidence of
incarceration or strangulation
Further anatomic considerations must be assessed in relation
to the above clinical findings. The location of the underlying
hernia may provide a unique constellation of symptoms with
or without specific anatomic findings.
1. Femoral hernia
 Medial thigh pain as well as groin pain are possible
because of the position of this hernia
2. Obturator hernia
 Because this hernia is hidden within deeper structures, it
may not present as a swelling
 The patient may complain of abdominal pain or medial
thigh pain, weight loss, or recurrent episodes of bowel or
partial bowel obstruction
 Pressure on the obturator nerve causes pain in the
medial thigh that is relieved by thigh flexion. This same
pain may be exacerbated by extension or external
rotation of the hip (Howship-Romberg sign)
3. Incisional hernia
 As these are usually asymptomatic, patients present with
a bulge at the site of a previous incision
 Lesion may become larger upon standing or with
increasing intra-abdominal pressure
Physical
In general, the physical examination should be performed
with the patient in both the supine and standing positions,
with and without the Valsalva maneuver. The examiner
should attempt to identify the hernia sac as well as the fascial
defect through which it is protruding. This allows proper
direction of pressure for reduction of hernia contents. The
examiner should also identify evidence of obstruction and
strangulation.
1. When attempting to identify a hernia, look for a swelling
or mass in the area of the fascial defect.
 Place a fingertip into the scrotal sac and advance up into
the inguinal canal. If the hernia is elsewhere on the
abdomen, attempt to define the borders of the fascial
defect.
 If the hernia comes from superolateral to inferomedial
and strikes the distal tip of the finger, it most likely is an
indirect hernia.
 If the hernia strikes the pad of the finger from deep to
superficial, it is more consistent with a direct hernia.
2. A bulge felt below the inguinal ligament is consistent
with a femoral hernia.
3. Strangulated
hernias
are
differentiated
from
incarcerated hernias by the following:
 Pain out of proportion to examination findings
 Fever or toxic appearance
 Pain that persists after reduction of hernia
Causes
Any condition that increases the pressure in the intraabdominal cavity may contribute to the formation of a
hernia, including the following:
1. Marked obesity
2. Heavy lifting
3. Coughing
4. Straining with defecation or urination
5. Ascites
6. Peritoneal dialysis
7. Ventriculoperitoneal shunt
8. Chronic obstructive pulmonary disease (COPD)
9. Family history of hernias
Differential Diagnoses
Epididymitis
Hidradenitis Suppurativa
Hydrocele
Lymphogranuloma Venereum
Testicular Torsion
Workup
Laboratory Studies
1. Complete blood count
 Results from CBC are nonspecific
 Leukocytosis with left shift may occur with strangulation
2. Electrolytes, BUN, creatinine levels
 Assess the hydration status of the patient with nausea
and vomiting
 These tests are rarely needed for patients with hernia
except as part of a preoperative workup
3.
Urinalysis: This test assists with narrowing the
differential diagnosis of genitourinary causes of groin
pain in the setting of associated hernias.
Imaging Studies
1. Imaging studies are not required in the normal workup
of a hernia.4,6
2. Ultrasonography can be used in differentiating masses in
the groin or abdominal wall or in differentiating
testicular sources of swelling.
3. If an incarcerated or strangulated hernia is suspected,
the following imaging studies can be performed:
 Upright chest radiograph to exclude free air (extremely
rare)
 Flat and upright abdominal films to diagnose a small
bowel obstruction (neither sensitive or specific) or to
identify areas of bowel outside the abdominal cavity
4. CT scanning or ultrasonography may be necessary in the
following cases:
 To diagnose a spigelian or obturator hernia
 Inability to obtain a good examination because of body
habitus
Treatment
Emergency Department Care
Reduction of a hernia
1. Provide adequate sedation and analgesia to prevent
straining or pain. The patient should be relaxed enough
to not increase intra-abdominal pressure or to tighten
the involved musculature.
2. Place the patient supine with a pillow under his or her
knees.
3. Place the patient in a Trendelenburg position of
approximately 15-20° for inguinal hernias.
4. Apply a padded cold pack to the area to reduce swelling
and blood flow while establishing appropriate analgesia.
5. Place the ipsilateral leg in an externally rotated and
flexed position resembling a unilateral frog leg position.
6. Place 2 fingers at the edge of the hernial ring to prevent
the hernial sac from riding over the ring during reduction
attempts.
7. Firm, steady pressure should be applied to the side of
the hernia contents close to the hernia opening, guiding
it back through the defect.
8. Applying pressure at the apex, or first point, that is felt
may cause the herniated bowel to "mushroom" out over
the hernia opening instead of advancing through it.
9. Consult with a surgeon if reduction is unsuccessful after
1 or 2 attempts; do not use repeated forceful attempts.
10. The spontaneous reduction technique requires adequate
sedation/analgesia, Trendelenburg positioning, and
padded cold packs applied to the hernia for a duration of
20-30 minutes. This can be attempted prior to manual
reduction attempts.
Treatment
Medical Therapy
Trusses place pressure on the skin and bowel, induce related
injury, and mask signs of incarceration and strangulation. The
temporary use of binders or corsets can be useful in patients
with large-necked hernias, during the preoperative period, or
with a high risk of operation on a long-term basis.
Reduction
Sedation, analgesia, and Trendelenburg positioning may aid
in the reduction of an incarcerated hernia. Ice cooling of an
incarcerated hernia is counterproductive. Simple pressure
over the distal sac usually is ineffective since the incarcerated
viscera then mushroom over the external ring. Pressure
directed medially at the external ring and maintained for
several minutes, while simultaneously invaginating the distal
sac, will often reduce a difficult incarcerated viscus.
Hernia content balloons over the external ring when
reduction is attempted.
Hernia can be reduced by medial pressure applied first.
In children, pressure should be applied from the posterior
and directed laterally and superiorly through the external
ring. Of note, the internal ring in infants is more medial than
in older children and adults. The hourglass configuration of a
hernia/hydrocele complex will not reduce with pressure
applied to the hydrocele portion.
Topical therapy
Cauterization with silver nitrate aids in the resolution of an
umbilical granuloma. If there is a stalk, ligation of the base
resolves the problem. Delaying the repair of umbilical or
asymptomatic epigastric hernias until children are older than
5 years allows spontaneous closure in most children.
Strapping, with or without a coin, is not indicated in the
treatment of umbilical hernia because of problems with skin
erosion and lack of effectiveness.
Grob introduced the use of Mercurochrome as an escharotic
for scarifying the intact sac of a giant omphalocele. However,
the development of mercury poisoning terminated its use.
Chemical dressings using silver sulfadiazine (complication is
leukopenia), povidone-iodine solution (complication is
hypothyroidism), 0.5% silver nitrate solution (complication is
argyrism), and gentian violet have served as agents to protect
against infection while the sac epithelializes. In current
practice, only life-threatening associated conditions, poor
probability of survival in infants, or failure of better means of
coverage warrant use of these methods. A large residual
ventral hernia results, which may be problematic because of
loss of domain.
Progressive compression dressing of an omphalocele sac with
an inner layer of saline moistened dressings and an outer
dressing of Coban can reduce viscera over 5-10 days, after
which delayed primary fascial and skin closure is
accomplished.
For children with an omphalocele and life-threatening
associated conditions, a poor probability of survival, or a very
large omphalocele, the combination of topical escharotic
agents and daily abdominal wrapping with an ACE bandage
has produced successful closure in many patients. As the
child grows, the defect remains the same size and becomes
smaller relative to the increasing abdominal wall. Delayed
closure following epithelialization can allow primary fascial
closure with no prosthesis, which eliminates the need for
multiple operations. External coverage with pigskin, skinlike
polymer membrane, or human amniotic membrane can be
used adjunctively in the treatment of giant omphalocele or
after failed primary therapy.
Surgical Therapy
Inguinal hernia
Treatment for adult inguinal hernia is described as follows:
After a diagnosis is established, the signs, symptoms, and
risks of incarceration, as well as the timing, conduct, and risk
of the repair procedure, should be explained to the patient or
to the parents of the child. Most repairs proceed within
several weeks and are dependent on multiple factors (eg,
employment, insurance).
Massive hernias need prosthetic material to aid closure in
most patients, and appropriate materials should be available
in the operating room prior to incision. Progressive
pneumoperitoneum, using increasing volumes of air over
time, may allow accommodation to increased intraabdominal pressure but probably does little to increase the
size of the abdominal cavity.
Adults with very large chronic hernias should be admitted
postoperatively because of the combination of ileus from
extensive manipulation and the loss of domain with the
attendant problems of increased pressure on the diaphragm,
vena cava, kidneys, and hernia closure. The adult who
presents with bilateral hernias without the need for formal
reconstruction can have simultaneous repair, whereas more
complex procedures should be metachronous by a month or
more.
Local anesthesia is sufficient for most repairs in adults;
however, prolonged procedures, repair of hernias with a
large intraperitoneal component, including laparoscopy, and
repair of recurrent hernias are best managed with spinal,
epidural, or general anesthesia.
The use of routine preoperative antibiotics in low-risk adults
undergoing a standard tension-free repair with mesh is not
currently recommended, as multiple studies have shown no
benefit in decreasing postoperative wound infection.
Pediatric surgeons repair soon after diagnosis, regardless of
age or weight, in healthy full-term infant boys with
asymptomatic reducible inguinal hernias.11 In full-term girls
with a reducible ovary, most surgeons operate at a close
elective date, but, if the ovary is not reducible but
asymptomatic, more urgent timing of surgery is preferred.
Premature infants with inguinal hernias are usually repaired
prior to discharge from the neonatal intensive care unit
(NICU), but this practice is changing, as infants are now being
discharged home at much lower weights. Some surgeons
prefer to postpone the surgery in these very small babies for
1-2 months to allow further growth. Apnea is common in
postoperative infants. These young infants should have an
apnea monitor during the postoperative period.12,13,14
All children with bilateral presentation should undergo
bilateral inguinal hernia repair under a single anesthesia.
However, potential damage to the spermatic cord structures
in boys argues against routine contralateral exploration.
Controversy exists over the routine exploration of the
opposite side in children with unilateral inguinal
hernias.15 Previous practices of routinely exploring the
opposite side in all boys younger than 2 years and all girls
younger than 4-5 years are no longer popular.
Most surgeons do not routinely perform open exploration of
the contralateral groin, except in cases of high anesthetic risk
(eg, congenital heart disease, premature infants), risk for
developing contralateral hernia secondary to increased intraabdominal
pressure
(eg,
peritoneal
dialysis,
ventriculoperitoneal shunt, ascites), or limited access of the
child to appropriate medical care should an incarceration
occur on the opposite side. Current practice in many
pediatric centers uses peritoneoscopy through the ipsilateral
inguinal sac to identify contralateral patent processes and
hernias. Long-term follow-up is needed because only 20% of
the patent processes identified become clinically apparent
hernias in the short term.
A surgeon who is unfamiliar with the tissue characteristics
and metabolic and psychological needs of children or who
does not have a skilled pediatric anesthesiologist available
should not attempt a hernia operation in a young child. Older
children usually have general inhalation anesthesia, whereas
some anesthesia providers use spinal or continuous caudal
anesthesia with preterm infants. Preemptive regional
anesthesia, by ilioinguinal and iliohypogastric nerve block or
by caudal block, decreases postoperative discomfort. The
routine use of perioperative antibiotics for uncomplicated
inguinal hernia repairs in children is not generally indicated.
Some cardiologists advise prophylactic antibiotic use to lower
the risk of endocarditis in children with associated cardiac
defects; patients with ventriculoperitoneal shunts may also
benefit.
Postoperative
apnea
is
common
in
premature
16
infants. Premature infants younger than 50 weeks’
gestational age should be admitted for 24 hours
postoperatively and placed on a cardiorespiratory monitor.
Patients undergoing a neurectomy have a significantly lower
prevalence of neuralgia without increased paresthesia.
Antibiotic prophylaxis is not indicated in low-risk adult
patients undergoing open mesh inguinal repair.
Preoperative Details
A full preoperative assessment and adequate fluid
resuscitation precede early operation. The fluid requirements
for an infant with gastroschisis are 2-8 times the usual
requirements for the first 24 hours of life because of the
visceral inflammation. Maintenance of urinary output of 1-2
cm3/kg/h by closely monitored administration of crystalloids
keeps the infant properly hydrated. A sump type nasogastric
tube should be passed through the mouth and into the
stomach and placed on suction to negate the effects of the
ileus.
Intraoperative Details
Surgical options depend on type and location of hernia.
The fundamentals of indirect inguinal hernia repair are
basically the same regardless of the age at presentation.
Reduction or excision of the sac and closure of the defect
with minimal tension are the essential steps in any hernia
repair. If tissue is sufficiently attenuated as to preclude
following these precepts, many techniques involving the
release of tension by flaps, prosthetic materials, or a simple
relaxing incision in adjacent tissue will fulfill the
requirements. Overlay, underlay, and sandwiching of the
edges with plastic meshes constitute most techniques today.
Return to work is dictated by the approach and the amount
of physical activity involved with the job. Accurate
postoperative instruction and easy access to care (if
problems arise) are as effective as a full postoperative visit
following routine inguinal hernia repairs.
Basic repair techniques - The Bassini repair
The essence of the Bassini repair is apposition of the
transversus abdominis, transversalis fascia, and lateral rectus
sheath to the inguinal ligament. This is usually performed by
imbrication. The Shouldice technique uses 2 layers of running
suture in a similar fashion.
Bassini-type
repair
approximating transversus
abdominis aponeurosis and
transversalis
fascia
to
iliopubic tract and inguinal
ligament.
Basic repair techniques - The Cooper repair
The greatest proponent of the Cooper repair is McVay. This
repair approximates the conjoint area, transversus
abdominis, and transversalis fascia to the pectineal ligament.
Overlying the vein, these structures are sewn to the iliopubic
tract. It also provides a good approach for the repair of
femoral hernias.
The standard adult hernia repair now uses prostheses to
reinforce the floor, usually polypropylene mesh. The material
can overlay, underlay, or sandwich the area or be used as a
plug. This provides a tension-free repair and excellent results,
but it carries a slightly increased risk of wound infection.
The preperitoneal approach has advocates who claim ease in
identifying the sac, reducing the contents, and dissecting the
cord structures. Mechanical advantages include the use of
natural intra-abdominal pressure to keep the mesh in place
over all potential hernia sites. The best uses are in the
incidental repair of a hernia during other abdominal
procedures, recurrent hernias, and femoral hernias. A
Pfannenstiel, lower midline, or other incision is used to reach
the preperitoneal plane. The internal inguinal ring and the
hernia sac are identified lateral to the inferior epigastric
vessels. After dissecting the sac from the testicular vessels
and vas deferens, it is divided and the peritoneum is closed.
The repair follows the pectineal approach and often has
mesh applied.
The laparoscopic approach is being increasingly used for both
primary hernias and recurrent hernias. The endoscopic totally
extraperitoneal approach (TEP) is usually favored over the
transabdominal preperitoneal operation (TAPP) because of
the complications that arise from exposed intraperitoneal
mesh in the TAPP repair. Postoperative pain, time to full
recovery, and return to work are improved with the
laparoscopic approach, but it is more expensive. Short-term
recurrence data are similar, but there has been insufficient
length of follow-up to completely compare it to the more
conventional approaches.
Complications
Iliohypogastric and ilioinguinal neuralgia usually will regress
within months. Nerve blocks or neurectomy can be used in
refractory cases.
Most recurrences happen within 5 years of operation and are
often associated with incarcerated hernias, concurrent
orchidopexy, sliding hernias in girls, and emergency
operations. The recurrence rate is higher in children younger
than 1 year and in the elderly. Recurrence is more common
in patients with ongoing increased intra-abdominal pressure,
growth failure and malnutrition, prematurity, seizure
disorder, and chronic respiratory problems. Technical factors
increasing recurrence include an unrecognized tear in the
sac, failure to repair a large internal inguinal ring, damage to
the floor of the inguinal canal, and infection or other
postoperative complications. A direct hernia sometimes
results from vigorous dissection or may have been a
simultaneous hernia unrecognized initially.
Other hernias
Recurrence, bleeding, infection, and persisting pain are
potential complications for the other abdominal wall hernias.
Incisional hernias may have a 30% rate of recurrence. The
addition of mesh to most abdominal wall hernia repairs is
decreasing the incidence of recurrence.
Outcome and Prognosis
Inguinal hernias
Hernia recurrence, infarcted testis or ovary with subsequent
atrophy, wound infection, bladder injury, iatrogenic
orchiectomy or vasectomy, and intestinal injury are
complications of hernia repair. (See image below.)
Postoperative death is usually related to complications, such
as strangulated bowel, or to preexisting risk factors. 20 A
postoperative hydrocele results from fluid accumulation in
the distal sac. This usually resolves spontaneously but
sometimes requires aspiration.
A femoral hernia as a sequela of inguinal hernia repair may
have been primarily overlooked. Unilateral transection of the
vas deferens can cause infertility through antibody
production. Iatrogenic cryptorchidism can occur in children
(1.3%) if the testicle is not placed in the scrotum at the end of
the operation and requires orchiopexy for correction.
For strangulated hernias, start broad-spectrum antibiotics.
Antibiotics are administered routinely if ischemic bowel is
suspected.
Antibiotics
These agents are to be used if the patient has a strangulated
hernia.
Uncomplicated inguinal and abdominal wall hernias do well.
However, hernias with associated strangulation have an
associated mortality rate of 10%. Infants with uncomplicated
gastroschisis and omphalocele fare well with a mortality rate
of less than 5%;22however, those with intestinal atresia or
severe associated anomalies have a mortality rate of 15-50%.
Consultations
Consult a surgeon for the following reasons: 1,16,3
1. Inability to reduce the hernia
2. Concern for a strangulated bowel and a patient with a
toxic appearance
3. Patients with comorbid risks for sedation should have a
surgeon present for the initial reduction attempt
Medication
Cefoxitin (Mefoxin)
Multiple regimens that cover for bowel perforation and/or
ischemic bowel can be used. Cover for both aerobic and
anaerobic gram-negative bacteria.
Adult
1-2 g IV q8h
Pediatric
80 mg/kg/d IV divided into 4 equal doses q6h
Follow-up
Further Inpatient Care
All incarcerated or strangulated hernias demand
admission and immediate surgical evaluation.
Further Outpatient Care
1. Follow-up visits with the general surgeon should be
scheduled within the next 1-2 weeks for those patients
with easily reducible hernias or with hernias found upon
physical examination.
2. Discharge patients with umbilical hernias with close
follow-up care if the defect is less than 2 cm in diameter
and the hernia is not incarcerated or strangulated.
3. Educate patients to avoid those activities that increase
intra-abdominal pressure.
4. Educate patients to return for inability to reduce hernia,
increased pain, fever, and vomiting.
Deterrence/Prevention
Counsel the patient on avoidance of activities that
increase intra-abdominal pressure, such as straining at
defecation or lifting heavy objects. This may require
work or school-related activity restrictions and should be
clearly delineated.
Complications
1. If strangulation of the hernia is missed, bowel
perforation and peritonitis can occur.
2. Hernias can reappear in the same location, even after
surgical repair.
Prognosis
1. The prognosis depends on the type and size of hernia as
well as on the ability to reduce risk factors associated
with the development of hernias.
2. The prognosis is good with timely diagnosis and repair.
Patient Education
1. Counsel the patient to avoid those activities that
increase intra-abdominal pressure, such as straining at
defecation and lifting heavy objects.
2. Instruct the patient to apply support to the
hernia. Numerous medical device companies have
developed support items to assist with this process.
3. Even with asymptomatic hernias, early repair (ie, before
it enlarges) is preferred. Referral to a general surgeon for
discussion about type of repair is warranted as a wide
variety of hernia repair options now exist with advent of
new meshes and laparoscopy.
Miscellaneous
Medicolegal Pitfalls
1. Failure to consider the diagnosis of hernia in patients
who present with nausea and/or vomiting
2. Diagnosing testicular torsion as a hernia without
appropriate evaluation or imaging considerations (puts
the testicle at risk)
3. Reducing a strangulated bowel without recognizing it
(The hernia will be reduced, but the bowel will remain
ischemic.)
4.
Failure to provide adequate instructions for patients with
reduced hernias regarding follow-up and the need to
return to the ED for worsening or persistent recurrent
symptoms
Special Concerns
Pain after reduction of a hernia may indicate a
strangulated hernia, requiring further evaluation by a
surgeon.