Hernias of the Groin
All hernias of the abdominal wall
consist of a peritoneal sac that protrudes through a weakness or defect in the
muscular layers of the abdomen. The defect may be congenital or acquired.
Just outside the peritoneum is
the transversalis fascia, an aponeurosis whose weakness or
defect is the major source of groin hernias. Next are found the transversus
abdominis, internal oblique, and external oblique muscles, which
are fleshy laterally and aponeurotic medially. Their aponeuroses form investing
layers of the strong rectus abdominis muscles above the
semilunar line. Below this line, the aponeurosis lies entirely in front of the
muscle. Between the two vertical rectus muscles, the aponeuroses meet again to
form the linea alba, which is well defined only above the
umbilicus. The subcutaneous fat contains the Scarpa fascia—a misnomer, since it
is only a condensation of connective tissue with no substantial strength.
In the groin, an indirect
inguinal hernia results when obliteration of the processus vaginalis,
the peritoneal extension accompanying the testis in its descent into the
scrotum, fails to occur. The resultant hernia sac passes through the internal
inguinal ring, a defect in the transversalis fascia halfway between
the anterior iliac spine and the pubic tubercle. The sac is located anteromedially
within the spermatic cord and may extend partway along the inguinal
canal or accompany the cord out through the subcutaneous (external)
inguinal ring, a defect medially in the external oblique muscle just above the
pubic tubercle. A hernia that passes fully into the scrotum is known as a complete
hernia. The sac and the spermatic cord are invested by the cremaster
muscle, an extension of fibers of the internal oblique muscle.
Other anatomic structures of the
groin that are important in understanding the formation of hernias and types of
hernia repairs include the conjoined tendon, or falx
inguinalis, a fusion of the medial aponeurotic transversus abdominis and
internal oblique muscles that passes along the inferolateral edge of the rectus
abdominis muscle and attaches to the pubic tubercle. Between the pubic tubercle
and the anterior iliac spine passes the inguinal (Poupart) ligament, formed
by the lowermost border of the external oblique aponeurosis as it rolls on
itself and thickens into a cord.
Just deep and parallel to the
inguinal ligament runs the iliopubic tract, a band of
connective tissue that extends from the iliopsoas fascia, crosses below the
deep inguinal ring, forms the superior border of the femoral sheath, and
inserts into the superior pubic ramus to form the lacunar (Gimbernat)
ligament. The lacunar ligament is about 1.25 cm long and triangular in
shape. The sharp, crescentic lateral border of this ligament is the unyielding
noose for the strangulation of a femoral hernia.
The Cooper ligament is
a strong, fibrous band that extends laterally for about 2.5 cm along the
iliopectineal line on the superior aspect of the superior pubic ramus, starting
at the lateral base of the lacunar ligament.
The Hesselbach triangle is
bounded by the inguinal ligament, the inferior epigastric vessels, and the
lateral border of the rectus muscle. A weakness or defect in the transversalis
fascia, which forms the floor of this triangle, results in a direct inguinal
hernia. In most direct hernias, the transversalis fascia is diffusely
attenuated, though a discrete defect in the fascia may occasionally occur.
This funicular type of direct inguinal hernia is more likely
to become incarcerated, since it has distinct borders.
A femoral hernia passes
beneath the iliopubic tract and inguinal ligament into the upper thigh. The
predisposing anatomic feature for femoral hernias is a small empty space
between the lacunar ligament medially and the femoral vein laterally—the femoral
canal. Because its borders are distinct and unyielding, a femoral
hernia has the highest risk of incarceration and strangulation of groin
hernias.
Surgeons must be familiar with the
pathways of the nerves and blood vessels of the inguinal region to avoid
injuring them when repairing groin hernias. The iliohypogastric nerve (T12, L1)
emerges from the lateral edge of the psoas muscle and travels inside the
external oblique muscle, emerging medial to the external inguinal ring to
innervate the suprapubic skin. The ilioinguinal nerve (L1) parallels the
iliohypogastric nerve and travels on the surface of the spermatic cord to
innervate the base of the penis (or mons pubis), the scrotum (or labia majora),
and the medial thigh. This nerve is the most frequently injured in anterior
open inguinal hernia repairs. The genitofemoral (L1, L2) and lateral femoral
cutaneous nerves (L2, L3) travel on and lateral to the psoas muscle and provide
sensation to the scrotum and anteromedial thigh and to the lateral thigh,
respectively. These nerves are subject to injury during laparoscopic hernia
repairs. The femoral nerve (L2–L4) travels from the lateral edge of the psoas
and extends lateral to the femoral vessels. It can be injured during
laparoscopic or femoral hernia repairs.
The external iliac artery travels
along the medial aspect of the psoas muscle and beneath the inguinal ligament,
giving off the inferior epigastric artery, which borders the medial aspect of
the internal inguinal ring. The corresponding veins accompany the arteries.
These vessels can be injured during hernia repairs of all types.
Nearly all inguinal hernias in
infants, children, and young adults are indirect inguinal hernias. Although
these "congenital" hernias most often present during the first year
of life, the first clinical evidence of hernia may not appear until middle or
old age, when increased intra-abdominal pressure and dilation of the internal
inguinal ring allow abdominal contents to enter the previously empty peritoneal
diverticulum. An untreated indirect hernia will inevitably dilate the internal
ring and displace or attenuate the inguinal floor. The peritoneum may protrude
on either side of the inferior epigastric vessels to give a combined direct and
indirect hernia, called a pantaloon hernia.
In contrast, direct inguinal
hernias are acquired as the result of a developed weakness of the
transversalis fascia in the Hesselbach area. There is some evidence that direct
inguinal hernias may be related to hereditary or acquired defects in collagen
synthesis or turnover. Femoral hernias involve an acquired
protrusion of a peritoneal sac through the femoral ring. In women, the ring may
become dilated by the physical and biochemical changes during pregnancy.
Any condition that
chronically increases intra-abdominal pressure may contribute to the appearance
and progression of a hernia. Marked obesity, abdominal strain from heavy
exercise or lifting, cough, constipation with straining at stool, and
prostatism with straining on micturition are often implicated. Cirrhosis with
ascites, pregnancy, chronic ambulatory peritoneal dialysis, and chronically
enlarged pelvic organs or pelvic tumors may also contribute. Loss of tissue
turgor in the Hesselbach area, associated with a weakening of the transversalis
fascia, occurs with advancing age and in chronic debilitating disease
Indirect & Direct Inguinal
Hernias
Most hernias produce no symptoms
until the patient notices a lump or swelling in the groin, though some patients
may describe a sudden pain and bulge that occurred while lifting or straining.
Frequently, hernias are detected in the course of routine physical
examinations such as preemployment examinations. Some patients complain of a
dragging sensation and, particularly with indirect inguinal hernias, radiation
of pain into the scrotum. As a hernia enlarges, it is likely to produce a sense
of discomfort or aching pain, and the patient must lie down to reduce the
hernia.
In general, direct hernias produce
fewer symptoms than indirect inguinal hernias and are less likely to become
incarcerated or strangulated.
Examination of the
groin reveals a mass that may or may not be reducible. The patient should be
examined both supine and standing and also with coughing and straining, since
small hernias may be difficult to demonstrate. The external ring can be identified
by invaginating the scrotum and palpating with the index finger just above and
lateral to the pubic tubercle (Figure 32–1). If the external ring is very
small, the examiner's finger may not enter the inguinal canal, and it may be
difficult to be sure that a pulsation felt on coughing is truly a hernia. At
the other extreme, a widely patent external ring does not by itself constitute
hernia. Tissue must be felt protruding into the inguinal canal during coughing
in order for a hernia to be diagnosed
Differentiating between direct and
indirect inguinal hernia on examination is difficult and is of little
importance, since most groin hernias should be repaired regardless of type.
Nevertheless, each type of inguinal hernia has specific features more common to
it. A hernia that descends into the scrotum is almost certainly indirect. On
inspection with the patient erect and straining, a direct hernia more commonly
appears as a symmetric, circular swelling at the external ring; the swelling
disappears when the patient lies down. An indirect hernia appears as an
elliptic swelling that may not reduce easily.
On palpation, the posterior wall of
the inguinal canal is firm and resistant in an indirect hernia but relaxed or
absent in a direct hernia. If the patient is asked to cough or strain while the
examining finger is directed laterally and upward into the inguinal canal, a
direct hernia protrudes against the side of the finger, whereas an indirect
hernia is felt at the tip of the finger.
Compression over the internal ring
when the patient strains may also help to differentiate between indirect and
direct hernias. A direct hernia bulges forward through Hesselbach triangle, but
the opposite hand can maintain reduction of an indirect hernia at the internal
ring.
These distinctions are obscured as a
hernia enlarges and distorts the anatomic relationships of the inguinal rings
and canal. In most patients, the type of inguinal hernia cannot be established
accurately before surgery.
Groin pain of musculoskeletal or
obscure origin may be difficult to distinguish from hernia. Herniography, in
which x-rays are obtained after intraperitoneal injection of contrast medium,
may aid in the diagnosis in cases of groin pain when no hernia can be felt even
after multiple maneuvers to increase intra-abdominal pressure.
Herniation of preperitoneal fat
through the inguinal ring into the spermatic cord ("lipoma of the
cord") is commonly misinterpreted as a hernia sac. Its true nature may
only be confirmed at operation. Occasionally, a femoral hernia that has
extended above the inguinal ligament after passing through the fossa ovalis
femoris may be confused with an inguinal hernia. If the examining finger is
placed on the pubic tubercle, the neck of the sac of a femoral hernia lies
lateral and below, while that of an inguinal hernia lies above.
Inguinal hernia must be
differentiated from hydrocele of the spermatic cord, lymphadenopathy or
abscesses of the groin, varicocele, and residual hematoma following trauma or
spontaneous hemorrhage in patients taking anticoagulants. An undescended testis
in the inguinal canal must also be considered when the testis cannot be felt in
the scrotum.
The presence of an impulse in the
mass with coughing, bowel sounds in the mass, and failure to transilluminate
are features that indicate that an irreducible mass in the groin is a hernia.
Although inguinal hernias have
traditionally been repaired electively to avoid the risks of incarceration,
obstruction, and strangulation, asymptomatic or mildly symptomatic hernias may
be safely observed in elderly, sedentary patients or those with high morbidity
for operation. The annual risk of hernia incarceration is not precisely known
but has been estimated at 2–3 per 1000 patients per year. All symptomatic groin
hernias should be repaired if the patient can tolerate surgery.
Even elderly patients tolerate
elective repair of a groin hernia very well when other medical problems are
optimally controlled and local anesthetic is used. Emergency operation carries
a much greater risk for the elderly than carefully planned elective operation.
If the patient has significant
prostatic hyperplasia, it is prudent to solve this problem first, since the
risks of urinary retention and urinary tract infection are high following
hernia repair in patients with significant prostatic obstruction.
Although most direct hernias do not
carry as high a risk of incarceration as indirect hernias, the difficulty in
reliably differentiating them from indirect hernias makes the repair of all
symptomatic inguinal hernias advisable. Direct hernias of the funicular type,
which are particularly likely to incarcerate, should always be repaired.
Because of the possibility of
strangulation, an incarcerated, painful, or tender hernia usually requires an
emergency operation. Nonoperative reduction of an incarcerated hernia may first
be attempted. The patient is placed with hips elevated and given analgesics and
sedation sufficient to promote muscle relaxation. Repair of the hernia may be
deferred if the hernia mass reduces with gentle manipulation and if there is no
clinical evidence of strangulated bowel. Though strangulation is usually
clinically evident, gangrenous tissue can occasionally be reduced into the
abdomen by manual or spontaneous reduction. It is therefore safest to repair
the reduced hernia at the earliest opportunity. At surgery, one must decide
whether to explore the abdomen to make certain that the intestine is viable. If
the patient has leukocytosis or clinical signs of peritonitis or if the hernia
sac contains dark or bloody fluid, the abdomen should be explored.
(1) Successful repair requires that
any correctable aggravating factors be identified and treated (chronic cough,
prostatic obstruction, colonic tumor, ascites, etc) and that the defect be
reconstructed with the best available tissues that can be approximated without
tension.
(2) An indirect
hernia sac should be anatomically isolated, dissected to its origin from the
peritoneum, and ligated (Figure 32–2). In infants and young adults in whom the
inguinal anatomy is normal, repair can usually be limited to high ligation,
removal of the sac, and reduction of the internal ring to an appropriate size.
For most adult hernias, the inguinal floor should also be reconstructed. The
internal ring should be reduced to a size just adequate to allow egress of the
cord structures. In women, the internal ring can be totally closed to prevent
recurrence through that site
4) Even though a direct hernia is
found, the cord should always be carefully searched for a possible indirect
hernia as well.
(5) In patients with large hernias,
bilateral repair has traditionally been discouraged under the assumption that
greater tension on the repair would result and therefore would increase the
recurrence rate and surgical complications. If open mesh repair or laparoscopic
methods are used, however, bilateral repairs can be done with low risk of
recurrence. In children and adults with small hernias, bilateral hernia repair
is usually recommended because it spares the patient a second anesthetic.
(6) Recurrent hernia within a few
months or a year of operation usually indicates an inadequate repair, such as
overlooking an indirect sac, missing a femoral hernia, or failing to repair the
fascial defect securely. Any repair completed under tension is subject to early
recurrence. Recurrences 2 or more years after repair are more likely to be
caused by progressive weakening of the patient's fascia. Repeated recurrence
after careful repair by an experienced surgeon suggests a defect in
collagen synthesis. Because the fascial defect is often small, firm, and
unyielding, recurrent hernias are much more likely than unoperated inguinal
hernias to develop incarceration or strangulation, and they should nearly
always be repaired again.
If recurrence is due
to an overlooked indirect sac, the posterior wall is often solid and removal of
the sac may be all that is required. Occasionally, a recurrence is discovered
to consist of a small, sharply circumscribed defect in the previous
hernioplasty, in which case closure of the defect suffices
Types of Operations for Inguinal
Hernia
The goal of all hernia repairs is to
reduce the contents of the hernia into the abdomen and to close the fascial
defect in the inguinal floor. Traditional repairs approximated native tissues
using permanent sutures. More recently, permanent mesh has supplanted tissue
repairs because multiple prospective, randomized studies have shown lower
recurrence with tension-free mesh repairs.
Over the past decade, increased
experience has been gained with minimally invasive techniques for hernia
repair. Although laparoscopic approaches offer less pain and more rapid return
to work or normal activities, randomized trials comparing open-end
laparoscopic hernia repairs do not demonstrate superiority of any specific
approach with regard to overall complications or recurrence rates. The success
of laparoscopic approaches is dependent on experience of the surgeon, as is
also true for open repair.
Although repairs today
overwhelmingly employ prosthetic material, the presence of infection or need to
resect gangrenous bowel may make use of nonbiologic mesh unwise. In these
situations, primary tissue repairs may still be a preferable option. For this
reason, surgeons need to know the traditional techniques even though they are
rarely used today.
Among the traditional autologous
tissue repairs, the Bassini repair is the most widely used
method. In this repair, the conjoined tendon is approximated to the Poupart
ligament, and the spermatic cord remains in its normal anatomic position under
the external oblique aponeurosis. The Halsted repair places
the external oblique beneath the cord but otherwise resembles the Bassini
repair. Cooper ligament (Lotheissen-McVay) repair brings the
conjoined tendon farther posteriorly and inferiorly to the Cooper ligament.
Unlike the Bassini and Halsted methods, McVay repair is effective for femoral
hernia but always requires a relaxing incision to relieve tension. Recurrence
rates after these open nonmesh repairs vary widely according to skill and
experience of the surgeon but range around 10%. Though the Shouldice
repair has a low reported recurrence rate, it is not widely used,
perhaps because of the more extensive dissection required and a belief
that the skill of the surgeons may be as important as the method itself. In the
Shouldice repair, the transversalis fascia is first divided and then imbricated
to the Poupart ligament. Finally, the conjoined tendon and internal oblique
muscle are also approximated in layers to the inguinal ligament.
The openpreperitoneal
approach exposes the groin from between the transversalis fascia and
peritoneum via a lower abdominal incision to effect closure of the fascial
defect. Because it requires more initial dissection and is associated with
higher morbidity and recurrence rates in less experienced hands, it has not
been widely used. For recurrent or large bilateral hernias, a preperitoneal
approach using a large piece of mesh to span all areas of potential herniation
has been described by Stoppa. Laparoscopic preperitoneal approaches have
demonstrated excellent success, with low recurrence and complications in
experienced hands.
A desire to decrease the recurrence
rate of hernias has prompted the increased use of prosthetic materials in
repair of both recurrent and first-time hernias. Methods include
"plugs" of mesh inserted into the internal ring and sheets of mesh to
create a tension-free repair. The most widely used technique is that of
Lichtenstein, an open mesh repair that allows an early return to normal
activities and a low complication and recurrence rate.
Virtually all laparoscopic
approaches utilize mesh in the repair. Several methods have been explored, from
a transabdominal intraperitoneal onlay of mesh (IPOM) to a transabdominal
preperitoneal mesh technique (TAPP) to total extraperitoneal (preperitoneal)
mesh placement (TEP). The high incidence of complications that occurred in
early studies prompted revisions in the operative technique to avoid injury to
lateral nerves. Several prospective randomized trials have subsequently been
conducted comparing open with minimally invasive techniques and one type of
minimally invasive technique with another. These studies generally have
demonstrated decreased pain and faster return to work with the minimally
invasive techniques but at increased time and cost of the procedure. Laparoscopic
procedures also require general anesthesia and therefore are not appropriate
for all patients. Because success of laparoscopic hernia repair is highly
dependent on the skill and experience of the surgeon, few inguinal hernias are
repaired laparoscopically. Specific situations in which minimally invasive
procedures may be particularly advantageous include the repair of multiply
recurrent hernias after anterior open repairs, repair of bilateral hernias
simultaneously, and repair in patients who must return to work particularly
quickly.
The surgeon is occasionally called
upon to prescribe a truss when a patient refuses operative repair or when there
are absolute contraindications to operation. A truss should be fitted to
provide adequate external compression over the defect in the abdominal wall. It
should be taken off at night and put on in the morning before the patient
arises. The use of a truss does not preclude later repair of a hernia, although
it may cause fibrosis of the anatomic structures, so that subsequent repair may
be more difficult.
Although groin hernia repair is
usually an outpatient procedure, a thorough preoperative evaluation should be
completed before the day of surgery. The anesthetic may be general, spinal, or
local. Local anesthetic is effective for most patients, and the incidence of
urinary retention and pulmonary complications is lowest with local anesthesia.
Recurrent hernias are more easily repaired with the patient under spinal or
general anesthesia, since local anesthetic does not readily diffuse through
scar tissue. A sedentary worker may return to work within a few days; heavy
manual labor has traditionally not been performed for up to 4–6 weeks after
hernia repair, though recent studies document no increase in recurrence when
full activity is resumed as early as 2 weeks after surgery, particularly when
open or laparoscopic mesh repairs have been used.
In addition to chronic cough,
prostatism, and constipation, poor tissue quality and poor operative technique
may contribute to recurrence of inguinal hernia. Because tissue is often more
attenuated in direct hernias, recurrence rates are higher than for indirect
hernias. Placing the repair under tension leads to recurrence. Failure to find
an indirect hernia, to dissect the sac high enough, or to adequately close the
internal ring may lead to recurrence of indirect hernia. Postoperative wound
infection is associated with increased recurrence. The recurrence rate is
considerably increased in patients receiving chronic peritoneal dialysis—in one
report, the rate was as high as 27%.
Recurrence rates after indirect
hernia repair in adults are reported at best to be 0.6–3%, though the incidence
is more probably 5–10%. Inadequate sac reduction or internal ring closure and
failure to identify a femoral or direct hernia contribute to recurrence.
A wide range of figures is quoted for recurrence after repair of direct
hernias, from less than 1% to as high as 28%. The point of recurrence is most
often just lateral to the pubic tubercle, implicating excessive tension on the
repair and adding evidence to favor mesh repairs or the use of a relaxing
incision in the rectus sheath if a traditional autologous tissue method is used
in the repair of a direct hernia. The use of mesh in hernia repairs decreases
the recurrence risk by 50–75%.
Another unappreciated
sequela of groin hernia repair is chronic groin pain, which may occur in as
high as 10% of patients and is usually attributed to nerve entrapment or
neuromaArvidsson D et al: Randomized clinical trial comparing 5-year recurrence rate after laparoscopic versus Shouldice repair of primary inguinal hernia
Sliding Inguinal Hernia
A sliding inguinal
hernia (Figures 32–4 and 32–5) is an indirect inguinal hernia in which the wall
of a viscus forms a portion of the wall of the hernia sac. On the right side,
the cecum is most commonly involved, and on the left side, the sigmoid colon.
The development of a sliding hernia is related to the variable degree of
posterior fixation of the large bowel or other sliding components (eg, bladder,
ovary) and their proximity to the internal inguinal ring
Clinical Findings
Though sliding hernias have no
special signs that distinguish them from other inguinal hernias, they should be
suspected in any large hernia that cannot be completely reduced. Finding a
segment of colon in the scrotum on contrast radiograph strongly suggests a
sliding hernia. Recognition of this variation is of great importance at
operation, since failure to recognize it may result in inadvertent entry into
the lumen of the bowel or bladder.
It is essential to recognize the
entity at an early stage of operation. As is true of all indirect inguinal
hernias, the sac will lie anteriorly, but the posterior wall of the sac will be
formed to a greater or lesser degree by colon or bladder.
After the cord has
been dissected free from the hernia sac, most sliding hernias can be reduced
by a series of inverting sutures
(Bevan technique) and one of the standard types of inguinal repair performed.
Very large sliding hernias may have to be reduced by entering the peritoneal
cavity through a separate incision (La Roque technique), pulling the bowel back
into the abdomen, and fixing it to the posterior abdominal wall. The hernia is
then repaired in the usual fashion.
The surgical
complication most often encountered following sliding hernia repair is bowel or
bladder injury. Injury can best be avoided by simply reducing the hernia and
sac into the preperitoneal space and repairing the hernia defect
Femoral Hernia
A femoral hernia descends through
the femoral canal beneath the inguinal ligament. Because of its narrow neck, it
is prone to incarceration and strangulation. Femoral hernia is much more common
in women than in men, but in both sexes femoral hernia is less common than
inguinal hernia. Femoral hernias comprise about one third of groin hernias in
women and about 2% of groin hernias in men.
Femoral hernias are
notoriously asymptomatic until incarceration or strangulation occurs. Even
with obstruction or strangulation,
the patient may feel discomfort more in the abdomen than in the femoral area.
Thus, colicky abdominal pain and signs of intestinal obstruction frequently are
the presenting manifestations of a strangulated femoral hernia, without
discomfort, pain, or tenderness in the femoral region.
A femoral hernia may present in a variety
of ways. If it is small and uncomplicated, it usually appears as a small bulge
in the upper medial thigh just below the level of the inguinal ligament.
Because it may be deflected anteriorly through the fossa ovalis femoris
to present as a visible or palpable mass at or above the inguinal ligament, it
can be confused with an inguinal hernia.
Femoral hernia must
be distinguished from inguinal hernia, a saphenous varix, and femoral
adenopathy. A saphenous varix transmits a distinct thrill when a patient
coughs, and it appears
and disappears instantly when the
patient stands or lies down—in contrast to femoral hernias, which are either
irreducible or reduce gradually on pressure.
The principles of femoral hernia
repair are as follows: (1) com-plete excision of the hernia sac, (2) the use of
nonabsorbable sutures, (3) repair of the defect in the transversalis fascia
that is responsible for the hernia, and (4) use of the Cooper ligament or
iliopubic tract for the repair, since these structures give a firm support for
sutures and form the natural line for closure of the defect.
A femoral hernia can be repaired
through an inguinal, thigh, preperitoneal, or abdominal approach, though the
inguinal approach is most commonly used. No matter what the approach, the
hernia is often difficult to reduce. Reduction may be facilitated by carefully
incising the iliopubic tract, Gimbernat ligament, or even the inguinal ligament.
Occasionally, a counterincision in the thigh is required to free attachments
below the inguinal ligament.
Irrespective of the approach used,
successful femoral hernia repair must close the femoral canal. The
Lotheissen-McVay repair, also used for inguinal hernia, is most commonly
employed.
If the hernia sac and mass reduce
when the patient is given opiates or anesthesia and if bloody fluid appears in
the hernia sac when it is exposed and opened, one must strongly suspect the
possibility of nonviable bowel in the peritoneal cavity. In such cases,
it is mandatory to open and explore the abdomen, usually through a separate
midline incision. The laparoscopic approach is well suited for repair of
femoral hernias.
Recurrence rates
usually approximate the middle range for direct inguinal hernia: about 5–10%
Umbilical Hernias in Adults
Umbilical hernia in adults occurs
long after closure of the umbilical ring and is due to a gradual yielding of
the cicatricial tissue closing the ring. It is more common in women than in
men.
Predisposing factors include (1)
multiple pregnancies with prolonged labor, (2) ascites, (3) obesity, and (4)
large intra-abdominal tumors.
In adults, umbilical hernia does not
usually obliterate spontaneously, as in children, but instead increases steadily
in size. The hernia sac may have multiple loculations. Umbilical hernias
usually contain omentum, but small and large bowel may be present. Emergency
repair is often necessary, because the neck of the hernia is usually quite
narrow compared to the size of the herniated mass and incarceration and
strangulation are common.
Umbilical hernias with tight rings
are often associated with sharp pain on coughing or straining. Very large umbilical
hernias more commonly produce a dragging or aching sensation.
Umbilical hernia in an adult should
be repaired expeditiously to avoid incarceration and strangulation. Repairs
utilizing mesh result in the lowest recurrence rate. The laparoscopic approach
is associated with less postoperative pain and faster recovery than open
techniques. Mesh should be used for all but the smallest umbilical hernias.
The presence of cirrhosis and
ascites does not contraindicate repair of an umbilical hernia, since
incarceration, strangulation, and rupture are particularly dangerous in
patients with these disorders. If significant ascites exists, however, it
should first be controlled medically or by TIPS (transjugular intrahepatic
portosystemic shunt) if necessary, since mortality, morbidity, and recurrence
are higher after hernia repair in patients with ascites. Preoperative
correction of fluid and electrolyte imbalance and improvement of nutrition
improves the outcome in these patients.
Factors that lead to
a high rate of complication and recurrence after surgical repair include large
size of the hernia, old age or debility of the patient, obesity, and the
presence of related intra-abdominal disease. In healthy individuals, surgical
repair of the umbilical defects gives good results with a low rate of
recurrence.An epigastric hernia (Figure 32–6) protrudes through the linea alba above the level of the umbilicus. The hernia may develop through one of the foramina of egress of the small paramidline nerves and vessels or through an area of congenital weakness in the linea alba
About 3–5% of the population have epigastric hernias. They are more common in men than in women and most common between the ages of 20 and 50. About 20% of epigastric hernias are multiple, and about 80% occur just off the midline
Epigastric Hernia
Clinical Findings
Most epigastric hernias are painless
and are found on routine abdominal examination. If symptomatic, their
presentation ranges from mild epigastric pain and tenderness to deep, burning
epigastric pain with radiation to the back or the lower abdominal quadrants.
The pain may be accompanied by abdominal bloating, nausea, or vomiting. The
symptoms often occur after a large meal and on occasion may be relieved by
reclining, probably because the supine position causes the herniated mass to
drop away from the anterior abdominal wall. The smaller masses most frequently
contain only preperitoneal fat and are especially prone to incarceration and
strangulation. These smaller hernias are often tender. Larger hernias seldom
strangulate and may contain, in addition to preperitoneal fat, a portion of the
nearby omentum and, occasionally, a loop of small or large bowel.
If a mass is palpable, the diagnosis
can often be confirmed by any maneuver that will increase intra-abdominal
pressure and thereby cause the mass to bulge anteriorly. The diagnosis is
difficult to make when the patient is obese, since a mass is hard to palpate;
ultrasound, CT, or tangential radiographs may be needed in the very obese
patient.
Differential diagnosis includes
peptic ulcer, gallbladder disease, hiatal hernia, pancreatitis, and upper small
bowel obstruction. On occasion, it may be impossible to distinguish the hernial
mass from a subcutaneous lipoma, fibroma, or neurofibroma.
Another condition that must be
distinguished from an epigastric hernia is diastasis recti, a
diffuse widening and attenuation of the linea alba without a fascial defect. On
examination, this condition appears as a fusiform, linear bulge between the two
rectus abdominis muscles without a discrete fascial defect. Although this
condition may be unsightly, repair should be avoided since there is no risk of
incarceration, the fascial layer is weak, and the recurrence rate is high.
Most epigastric hernias should be
repaired, since small ones are likely to become incarcerated and large ones are
often symptomatic and unsightly. Small defects can usually be closed primarily,
although mesh should be used for large hernias. Herniated fat contents are
usually dissected free and removed. Intraperitoneal herniating structures are
reduced, but no attempt is made to close the peritoneal sac.
The recurrence rate
is 10–20%, a higher incidence than with the routine inguinal or femoral hernia
repair. This high recurrence rate may be partly due to failure to recognize and
repair multiple small defects
Incisional Hernia (Ventral Hernia)
About 10% of abdominal operations
result in incisional hernias. The incidence of this iatrogenic type of hernia
is not diminishing in spite of an awareness of the many causative factors.
The factors most often responsible
for incisional hernia are listed below. When more than one factor coexists in
the same patient, the likelihood of postoperative wound failure is greatly
increased.
(1) Poor surgical technique.
Inadequate fascial bites, tension on the fascial edges, or too tight a closure
are most often responsible for incisional failure.
(4) General debility. Cirrhosis,
carcinoma, and chronic wasting diseases are factors that affect wound healing
adversely. Any condition that compromises nutrition increases the likelihood of
incision breakdown.
(5) Obesity. Obese patients
frequently have increased intra-abdominal pressure. The presence of fat in the
abdominal wound masks tissue layers and increases the incidence of seromas and
hematomas in wounds.
(6) Postoperative pulmonary
complications that stress the repair as a result of vigorous coughing. Smokers
and patients with chronic pulmonary disease are therefore at increased risk of
fascial disruption.
Small
incisional hernias should be treated by early repair since they may cause bowel
obstruction. If the patient is unwilling to undergo surgery or is a poor
surgical risk, symptoms may be controlled by an elastic corset.
Defects too large to close easily
may be left without surgical repair if they are asymptomatic, since they are
unlikely to incarcerate.
Small incisional hernias (< 2 cm
in diameter) usually require only a direct fascia-to-fascia repair for
satisfactory closure. Interrupted or continuous closure may be used, but the
sutures should be nonabsorbable. Sutures tied too tightly or tension on the
repair will predispose to recurrence.
Although no specific diameter
distinguishes a small from a large hernia, a hernia can be considered large
when the fascial edges cannot be approximated without tension.
In performing the repair, excess and
scarred skin and subcutaneous tissues over the hernia are removed. The hernia
sac is then carefully dissected free from the underlying muscles and fascial
tissues. If there are no adherent intraperitoneal structures, the sac may be
inverted and the repair done over the inverted sac. If there is incarceration
or adhesion of intraperitoneal contents, the abdominal contents should be
dissected free from the sac and dropped back into the abdomen. The edges of the
fascial defect should be cleaned so that the closure will be to solid fascial
tissue rather than to scar.
Primary closure of a
large defect is not advisable, since tension on the closure increases the risk
of
hernia recurrence. Increasingly,
repair of large or recurrent defects is performed using nonabsorbable mesh.
Although a variety of techniques exist for placement of the mesh, a retrorectus
underlay or a sandwich technique achieves a lower recurrence rate than an
edge-to-edge or onlay placement. If a large dead space persists, a closed
drainage system is usually employed in the space above the fascia. A primary
fascial closure should be used only if the fascia can be brought together
without tension and only for the smallest of defects.
Laparoscopic techniques are
increasingly being used to repair incisional hernias and perform adhesiolysis
electively. A sheet of synthetic material is secured to the abdominal wall as
an underlay graft; the intraperitoneal placement of the graft enhances the
durability of the repair, though it also increases the risk of bowel adhesions
or fistula formation.
Alternative methods close the
fascial defect using the patient's native tissues, such as a component
separation technique, sliding myofascial flap, or lateral counterincisions in
the anterior rectus sheath to allow primary closure in the midline. These
techniques can be used to avoid the need for mesh and are especially indicated
when the procedure is infected or contaminated, making synthetic mesh an unwise
choice. Newer biologic mesh of human or animal origin may also be used, though
recurrence rates with these materials are high.
Results of randomized
clinical trials show that mesh repair is superior to primary suture repair,
even for small incisional hernias; in one study with a median follow up of 75
and 81 months for suture and mesh repairs, suture repairs showed 63% recurrence
and mesh repair only 32%. Despite the increasing use of both open and
laparoscopic mesh repairs, however, population-based studies show that
incisional hernias continue to recur at a high rate after repair, and the
5-year reoperative rate increases with each subsequent reoperation for
recurrence, reaching almost 40% on average after the third recurrence. It is yet
to be known whether long-term results with laparoscopic mesh repairs will show
improved results. Factors shown to increase risk of hernia recurrence include
wound infection, presence of abdominal aneurysms, smoking, and poor nutrition.
In all techniques employing mesh, the underlay technique with at least 3–4 cm
of underlay of the mesh leads to the lowest recurrence rates. In addition to a
high recurrence rate after operations, complications such as infected mesh,
bleeding, seroma, and erosion of mesh into bowel causing a fistula occur in a
small percentage of cases. Mesh infection is more likely after repair of a
hernia occurring in a wound with a previous infection
Various Rare Herniations through the
Abdominal Wall
A Littre hernia is a hernia that
contains a Meckel diverticulum in the hernia sac. Although Littre first
described the condition in relation to a femoral hernia, the relative
distribution of Littre hernias is as follows: inguinal, 50%; femoral, 20%; umbilical,
20%; and miscellaneous, 10%. Littre hernias of the groin are more common in men
and on the right side. The clinical findings are similar to those of Richter
hernia; when strangulation is present, pain, fever, and manifestations of small
bowel obstruction occur late.
Treatment consists of repair of the
hernia plus, if possible, excision of the diverticulum. If acute Meckel
diverticulitis is present, the acute inflammatory mass may have to be treated
through a separate abdominal incision.
Spigelian hernia is an acquired
ventral hernia through the linea semilunaris, the line where the sheaths of the
lateral abdominal muscles fuse to form the lateral rectus sheath. Spigelian
hernias are nearly always found above the level of the inferior epigastric
vessels. They most commonly occur where the semicircular line (fold of Douglas)
crosses the linea semilunaris.
The presenting symptom is pain that
is usually localized to the hernia site and may be aggravated by any maneuver
that increases intra-abdominal pressure. With time, the pain may become more
dull, constant, and diffuse, making diagnosis more difficult.
If a mass can be demonstrated, the
diagnosis presents little difficulty. The diagnosis is most easily made with
the patient standing and straining; a bulge then presents in the lower
abdominal area and disappears with a gurgling sound on pressure. Following
reduction of the mass, the hernia orifice can usually be palpated.
Diagnosis is often made more
difficult because the hernial defect may lie beneath an intact external oblique
layer and therefore not be palpable. The hernia often dissects within the
layers of the abdominal wall and may not present a distinct mass, or the mass
may be located at a distance from the linea semilunaris. Patients with
spigelian hernias should have a tender point over the hernia orifice, though
tenderness alone is not sufficient to make the diagnosis. Both ultrasound and
CT scan may help to confirm the diagnosis.
Spigelian hernias have a high
incidence of incarceration and should be repaired. These hernias are quite
easily cured by primary aponeurotic closure. Laparoscopic repair may decrease
morbidity and hospital stay.
Lumbar or Dorsal Hernia
Lumbar or dorsal hernias are
hernias through the posterior abdominal wall at some level in the lumbar
region. The most common sites (95%) are the superior (Grynfeltt) and inferior
(Petit) lumbar triangles. A "lump in the flank" is the common
complaint, associated with a dull, heavy, pulling feeling. With the patient
erect, the presence of a reducible, often tympanitic mass in the flank usually
makes the diagnosis. Incarceration and strangulation occur in about 10% of
cases. Hernias in the inferior lumbar triangle are most often small and occur
in young, athletic women. They present as tender masses producing backache and
usually contain fat. Lumbar hernia must be differentiated from abscesses,
hematomas, soft tissue tumors, renal tumors, and muscle strain
Acquired hernias may be traumatic or
nontraumatic. Severe direct trauma, penetrating wounds, abscesses, and poor
healing of flank incisions are the usual causes. Congenital hernias occur in
infants and are usually isolated unilateral congenital defects.
Lumbar hernias increase in size and
should be repaired when found. Repair is by mobilization of the nearby fascia
and obliteration of the hernia defect by precise fascia-to-fascia closure. The
recurrence rate is very low.
Herniation through the obturator
canal is more frequent in elderly women and is difficult to diagnose
preoperatively. The mortality rate (13–40%) of these hernias makes them the
most lethal of all abdominal hernias. These hernias most commonly present as small
bowel obstruction with cramping abdominal pain and vomiting. The hernia is
rarely palpable in the groin, though a mass may be felt on pelvic or rectal
examination. The most specific finding is a positive Howship-Romberg sign, in
which pain extends down the medial aspect of the thigh with abduction,
extension, or internal rotation of the knee. Since this sign is present in
fewer than half of cases, diagnosis should be suspected in any elderly
debilitated woman without previous abdominal operations who presents with a
small bowel obstruction. Though diagnosis can be confirmed by CT scan,
operation should not be unduly delayed if complete bowel obstruction is
present.
The abdominal approach gives the
best exposure; these hernias should not be repaired from the thigh approach.
The Cheatle-Henry approach (retropubic) may also be used. Simple repair is most
often possible, though bladder wall, pectineal muscle, peritoneum, or
mesh has been used when the defect cannot be approximated primarily.
A perineal hernia protrudes through
the muscles and fascia of the perineal floor. It may be primary but is usually
acquired following perineal prostatectomy, abdominoperineal resection of the
rectum, or pelvic exenteration.
These hernias present as easily
reducible perineal bulges and usually are asymptomatic but may present with
pain, dysuria, bowel obstruction, or perineal skin breakdown.
Repair is usually done by an
abdominal approach, with an adequate fascial and muscular perineal repair.
Occasionally, polypropylene (Marlex) mesh or flaps using the gracilis, rectus
abdominis, or gluteus may be necessary, when the available tissues are too
attenuated for adequate primary repair.
Interparietal hernias, in which the
sac insinuates itself between the layers of the abdominal wall, are usually of
an indirect inguinal type but, rarely, may be direct or ventral hernias.
Although interparietal hernias are rare, it is essential to recognize them,
because strangulation is common and the mass is easily mistaken for a tumor or
abscess. The lesion usually can be suspected on the basis of the physical
examination provided it is kept in mind. In most cases, extensive studies for
intra-abdominal tumors have preceded diagnosis. A lateral film of the abdomen
will usually show bowel within the layers of the abdominal wall in cases with
intestinal incarceration or strangulation, and an ultrasound or CT scan may be
diagnostic.
As soon as the diagnosis is
established, operation should be performed, usually through the standard
inguinal approach.
Sciatic hernia is the
rarest of abdominal hernias and consists of an outpouching of intra-abdominal
contents through the greater sciatic foramen. The diagnosis is made after incarceration
or strangulation of the bowel occurs. The repair is usually made through the
abdominal approach
The
hernia sac and contents are reduced, and the weak area is closed by making a
fascial flap from the superficial fascia of the piriformis muscle.
Traumatic Hernia
Abdominal wall
hernias occur rarely as a direct consequence of direct blunt abdominal injury.
The patient presents with abdominal pain. On examination, ecchymosis of the
abdominal wall and a bulge are usually present. The existence of a hernia may
not be obvious, however, and the patient may require CT scan to confirm it.
Because of the high incidence of associated intra-abdominal injuries,
laparotomy is usually required. The defect should be repaired primarily if
possible.
Congenital Defects
Congenital defects of
the abdominal wall other than hernias or lesions of the urachus and
umbilicus
Trauma to the Abdominal Wall
This is a rare but important entity that may follow mild
trauma to the abdominal wall or may occur spontaneously in patients with
disorders of coagulation, blood dyscrasia, or degenerative vascular diseases.
Abdominal
pain localized to the rectus muscle is the presenting symptom. The pain may be
sudden and severe in onset or slowly progressive. The key to diagnosis is the
physical examination. Careful palpation will reveal a tender mass within the
abdominal wall. When the patient tenses the rectus muscles by raising the head
or body, the swelling becomes more tender and distinct on palpation, in
contrast to an intra-abdominal mass or tenderness that disappears when the
rectus muscles are contracted (Fothergill sign). In addition, there may be
detectable discoloration or ecchymosis. If the physical signs are not
diagnostic, ultrasound or CT scan will demonstrate the hematoma in the
abdominal wall.
The condition does
not commonly require operation. The acute pain and discomfort usually disappear
within 2 or 3 days, although a residual mass may persist for several weeks. If
pain is severe, an acceptable alternative is evacuation of the clot and control
of the bleeding
Pain in the Abdominal Wall
A number of conditions are
characterized by pain in the abdominal wall without a demonstrable organic
lesion. Pain from a diaphragmatic, supradiaphragmatic, or spinal cord lesion may
be referred to the abdomen. Herpes zoster (shingles) may present as abdominal
pain, in which case it will follow a dermatomal distribution.
Entrapment of a nerve by a
nonabsorbable suture may cause persistent incisional pain, sometimes quite
severe. Hyperesthesia of the skin over the involved dermatome may provide a
clue to the cause. If local anesthetic nerve block relieves the pain, nerve block
with alcohol or nerve excision may be performed.
In all cases of
localized pain in the abdominal wall, careful search should be made for a small
hernia: MRI or CT scan may be helpful to rule out a hernia.
Abdominal Wall Tumors
Tumors of the abdominal wall are
quite common, but most are benign, eg, lipomas, hemangiomas, and fibromas.
Musculoaponeurotic fibromatoses (desmoid tumors), which often occur in
abdominal wall scars or after parturition in women
Endometriomas may
also occur in the abdominal wall, particularly in the scars from gynecologic
procedures and Caesarian sections. Most malignant tumors of the abdominal wall
are metastatic. Metastases may appear by direct invasion from intra-abdominal
lesions or by vascular dissemination. The sudden appearance of a sensitive
nodule anywhere in the abdominal wall that is clearly not a hernia should
arouse suspicion of an occult cancer, the lung and pancreas being the more
likely primary sites