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142 Part II Abdominal Wall
against herniation of intra-abdominal contents through defects
in the midline fascia. A paraumbilical hernia is an epigastric
hernia that borders on the umbilicus.
History
e epigastric hernia was rst described by Villeneuve in
1285, but the term “epigastric hernia” was only rst used
to describe this condition in 1812 by Leville. e rst successful repair of an epigastric hernia was reported in 1802 by
Maunior.
Incidence
Estimates of the frequency of epigastric hernia in the general population range from 3% to 5%. It is most commonly
diagnosed in middle age, and congenital epigastric hernias
are uncommon. e condition is more common in males by
a ratio of 3:1. Twenty percent of epigastric hernias may be
multiple, although most are associated with one dominant
defect.
Anatomy and Etiology
e cause of epigastric hernia is largely unknown. Since the
condition does not predominate in children, it is unlikely
that the defect is entirely congenital in origin. Rather, the
hernia is likely the result of multiple factors, such as a congenitally weakened linea alba from a lack of decussating midline
bers and subsequent increase in intra-abdominal pressure,
surrounding muscle weakness, or chronic abdominal wall
strain.
e midline defect is usually elliptical in nature, with
the long axis oriented transversely. e width of the defect
is generally a few millimeters to several centimeters, and
larger defects are rare. In most cases, the hernia is lled
by a small amount of preperitoneal fat only and no peritoneal sac is present. e hernia will often not be seen on
laparoscopy owing to the lack of peritoneal involvement
through the hernia defect. Epigastric hernias that involve
a peritoneal sac usually contain only omentum and rarely
small intestine.
Clinical Manifestations
Epigastric hernia is often asymptomatic and represents a chance
nding on physical examination. Patients with symptomatic
hernias complain of vague abdominal pain above the umbilicus
that is exacerbated with standing or coughing and relieved in
the supine position. Severe pain may be secondary to incarceration or strangulation of preperitoneal fat or omentum. Bowel
strangulation in epigastric hernias is a rare nding.
On examination, the hernia is diagnosed by palpating
a small, soft, reducible mass in the midline superior to the
umbilicus. e mass may protrude with a Valsalva maneuver or with standing. Palpation can be especially dicult in
the obese patient. Rarely, imaging is needed to conrm the
diagnosis, and computed tomography of the abdomen is the
preferred technique.
Treatment
As illustrated in Fig. 7-9, operative repair of the epigastric
hernia can most often be performed as a day-surgery procedure under local anesthesia. General anesthesia should
be reserved for the complicated patient, a very large hernia, or the pediatric population. e herniated contents are
exposed through a small midline vertical or transverse incision. e defect in the linea alba and the surrounding fascia
are cleared of subcutaneous fat. Eort is made to identify a
peritoneal sac protruding through the defect. If identied, a
small sac can be simply inverted back within the abdominal
cavity. Alternatively, a larger sac can be opened, its contents
reduced, and any excess peritoneum excised. It is usually not
necessary to perform formal closure of the peritoneal sac.
e defect is then closed transversely with a few interrupted
sutures of polypropylene or nylon, taking generous bites of
surrounding fascia.
is repair usually suces with minimal recurrence. In
general, it is not necessary to reconstruct the linea alba for
a single epigastric hernia. Most patients will not develop a
subsequent epigastric hernia at a separate site, and repair of
an epigastric hernia is a minor ambulatory procedure that can
be repeated easily if necessary.
OBTURATOR HERNIA
An obturator hernia is one of the rarest forms of hernia, and
most surgeons will see few in an entire career. An obturator
hernia occurs when there is protrusion of intra-abdominal
contents through the obturator foramen in the pelvis.
Incidence
e true incidence of obturator hernia is unknown. e
largest reported series includes only 43 patients diagnosed
with obturator hernia over a 30-year period.
that less than 1% of mechanical bowel obstructions arise
from strangulated obturator hernias. e hernia is much
more common in females, with a female:male ratio of 6:1.
e gender discrepancy is often explained by dierences in
female pelvic anatomy, including a broader pelvis, a wide
obturator canal, and the increase in pelvic diameter brought
about by pregnancy. Most cases of obturator hernia present in
the seventh and eighth decades, and this condition is clearly
34
It is thought
Chapter 7 Hernias 143
C
A
D
B
E
F
FIGURE 7-9 Repair of the epigastric hernia. A. e elliptical opening. B. e diamond-shaped opening. C. e small empty sac. D. Herniated
fat exposed during dissection. E. Herniated fat and the sac have been excised. F. Repair of continuous suture technique. G. Repair using interrupted
sutures.
associated with advanced age. Bilateral obturator hernias have
been reported in 6% of cases.
G
obturator canal are the obturator groove on the superior
pubic ramus superiorly and the upper edge of the obturator membrane inferiorly. e canal is approximately 3 cm
in length, and the obturator vessels and nerve lie postero-
Anatomy
lateral to the hernia sac in the canal. e hernia sac usually
takes the shape of the canal so that it is long and narrow
e obturator foramen is formed by the ischial and pubic
rami (Fig. 7-10). e obturator membrane covers the
majority of the foramen space, except for a small portion
through which the obturator vessels and nerve pass. ese
vessels traverse the canal to leave the abdominal cavity and
enter the medial aspect of the thigh. e boundaries of the
before ballooning in the upper thigh. e hernia lies deep to
the pectineus muscle and therefore is dicult to palpate on
examination. Small bowel is the most likely intra-abdominal
organ to be found in an obturator hernia, although rare cases
have been reported of the appendix, Meckel’s diverticulum,
omentum, bladder, and ovary incarcerated in the hernia.
144 Part II Abdominal Wall
FIGURE 7-10 e direction of the obturator hernia through the
obturator canal.
Clinical Manifestations
Obturator hernia is associated with four cardinal ndings that
assist in the dicult diagnosis. Rarely do all four physical ndings occur together. e most common clinical manifestation
is intestinal obstruction, which occurs in over 80% of patients.
is is often in the form of acute obstruction secondary to
35
hernia strangulation.
e second most common nding is
the Howship–Romberg sign, seen in about one-half of patients
with obturator hernia. With this sign, patients characteristically
complain of pain along the medial surface of the thigh that may
radiate to the knee and hip joints. e nding is likely associated with compression of the obturator nerve between the canal
and the hernia sac. e adductor reex in the thigh may also
be weakened or lost secondary to motor dysfunction from an
entrapped obturator nerve. e third nding, observed in 30%
of patients, is a history of repeated episodes of bowel obstruction that pass quickly and without intervention. is is likely
due to periodic incarceration of the hernia sac in the obturator
canal. Finally, a fourth nding is a palpable mass in the proximal medial aspect of the thigh at the origin of the adductor
muscles. e palpable mass is only found in an estimated 20%
of patients with obturator hernia. e mass is best palpated
with the thigh exed, abducted, and rotated outward.
In rare cases, ecchymoses may be noted in the upper medial
thigh due to eusion from the strangulated hernia contents.
e obturator hernia mass may also be palpated laterally on a
vaginal examination.
Treatment
e only treatment for obturator hernia is surgical repair. All
obturator hernias should be operated on soon after diagnosis
given the high risk for bowel incarceration and strangulation.
ere is no role for conservative management given the
location of the hernia and the fact that the strangulated obturator hernia is dicult to diagnose. A preoperative diagnosis
of obturator hernia is rare indeed, and a diagnosis prior to
presentation with bowel obstruction is even more uncommon. e typical case of obturator hernia presents as an acute
small bowel obstruction with evidence of ischemic bowel
on examination, laboratory analyses, or imaging. erefore,
obturator hernia repair is often performed as a surgical emergency via a midline laparotomy.
ere are three general operative approaches for obturator hernia repair: the lower midline transperitoneal approach,
the lower midline extraperitoneal approach, and the anterior
thigh exposure.
e lower midline transperitoneal approach is the most
common method for repair of obturator hernias since most
cases are encountered unexpectedly during exploratory laparotomy for small bowel obstruction of unknown etiology.
Following laparotomy, the dilated small bowel is run deep
into the pelvis where it is found to enter the obturator canal
alongside the obturator vessels and nerve. A careful attempt
should be made to reduce the incarcerated bowel with gentle
traction. is maneuver may be augmented by palpation
on the medial inner thigh to push the hernia sac into the
abdominal cavity from the outside. is is dicult to perform
without assistance since the thigh is rarely sterilely prepared
for the exploratory laparotomy unless a preoperative diagnosis of obturator hernia has been made. e pelvic side of the
obturator canal has a rigid opening that cannot be digitally
dilated, making reduction of the hernia sac more dicult.
If traction alone does not allow reduction of the bowel, the
obturator membrane can be carefully incised from anterior
to posterior to facilitate exposure. Care should be taken to
avoid injury to both the incarcerated bowel and the obturator vessels. If these maneuvers are unsuccessful, a counter
incision can be made in the medial groin to facilitate reduction from both sides of the canal. Once the hernia has been
reduced, the intestine is assessed for viability and resected as
needed. e hernia opening is then closed around the obturator vessels with a running layer of polypropylene or nylon
suture applied in the thin layer of fascia that encircles the
inner circumference of the canal. Alternatively, in a clean case
without bowel contamination, a piece of mesh can be placed
over the obturator foramen. Some hernia surgeons suture the
mesh to Cooper’s ligament to avoid migration.
e midline extraperitoneal approach is used when the
diagnosis of obturator hernia has been made preoperatively.
It allows complete exposure of the opening of the obturator
canal. e incision is made in the midline from the umbilicus to the pubis. e preperitoneal plane is entered deep to
the rectus muscle, and the bladder is peeled from the peritoneum. e space is opened so that the superior pubic ramus
and the obturator internus muscle are exposed. e hernia sac
is seen as a projection of peritoneum passing inferiorly into
the obturator canal. e sac is incised at the base, the contents are reduced, and the neck of the sac is transected. Any
remaining distal sac in the canal is extracted by traction or
Chapter 7 Hernias 145
tomographic imaging techniques. Recurrence rates are low
in published series, although long-term follow-up has proved
dicult in this patient population.
PERINEAL HERNIAS
Hernias of the perineum are rare and composed of protrusions of the intra-abdominal contents through a weakened
pelvic oor. ey may also be termed pelvic hernias, ischiorectal hernias, pudendal hernias, subpubic hernias, or hernias of the pouch of Douglas. Perineal hernias should be
dierentiated from the more common rectocele or cystocele,
which are related to pelvic oor relaxation, most often from
childbirth, and do not represent true hernias.
Primary perineal hernias are extremely rare. e rst
reported case was by Scarpa in 1821. Secondary, or postoper-
FIGURE 7-11 e thigh approach for repair of the obturator hernia.
with long forceps. e internal opening to the obturator canal
is closed with a continuous suture as described above. e
bites of tissue should include the periosteum of the superior
pubic ramus and the fascia on the internal obturator muscle.
Care must be exercised at all times to avoid injury to the obturator vessels and nerve that run alongside the hernia defect. In
addition to or in place of the suture closure of the obturator
defect, preperitoneal mesh placement has been described to
cover the defect.
e thigh approach begins with a vertical incision in
the upper medial thigh placed along the adductor longus
muscle (Fig. 7-11). e muscle is retracted medially to
expose thepectineus muscle, which is cut across its width
to expose the sac. e sac is carefully incised, the contents
inspected and reduced if viable, and the sac is excised. e
hernial opening is closed with a continuous suture layer.
If the bowel contents within the hernia sac do not appear
viable, it is dicult to perform an adequate small bowel
resection through the thigh incision and therefore midline
laparotomy is usually performed.
Laparoscopic transperitoneal and extraperitoneal
approaches have been recently described for obturator
hernia repair withplacement of prosthetic mesh to close the
obturator opening.
36
Results
Mortality after obturator hernia repair has been much higher
than with other hernias because it is associated with acute
bowel obstruction in an elderly population with multiple
comorbidities. Recent data show a mortality of less than
5% and a 25% incidence of small bowel resection during
obturator hernia repair.
et in accuracy in the modern era aorded by computed
34
ese reports emphasize the ben-
ative, perineal hernias are more commonly seen and occur in
patients status postabdominoperineal resection in which the
pelvic musculature is dissected to resect the distal rectum.
Etiology
Primary perineal hernias occur in the older population, usually
between the fth and seventh decades of life. ey are at least
ve times more common in women than in men, and this is
thought to be associated with the broader pelvic oor in the
female and long-term eects of pregnancy and childbirth. Factors that may predispose to a primary perineal hernia include a
deep or elongated pouch of Douglas, obesity, chronic ascites,
history of pelvic infection, and obstetric trauma.
Postoperative perineal hernia may occur in patients who
have undergone abdominoperineal resection or pelvic exenteration. It is thought to form as a result of excision of the
levator ani musculature and its surrounding fascia with
incomplete repair of the pelvic oor. An excision of the coccyx is thought to be an additional aggravating factor in hernia
formation. As in primary perineal hernias, women are aected
more often than men. e condition, while more common
than the primary perineal hernia, remains rare.
Anatomy
e pelvic oor is formed by the levator ani and iliococcygeus muscles and their fascia. e pelvic outlet is bounded
by the pubic symphysis and the subpubic ligament anteriorly, the pubic rami and ischial tuberosities laterally, and the
coccyx and sacrotuberous ligaments posteriorly. e outlet is
divided into anterior and posterior divisions by the supercial transversus perinei muscles. e anterior space is termed
the urogenital triangle, and the posterior space is termed the
ischiorectal fossa. Anterior and posterior perineal hernias are
named according to the location of the hernia defect and subsequent sac protrusion, as shown in Fig. 7-12.
146 Part II Abdominal Wall
FIGURE 7-12 e anatomy of the perineal hernia showing the
location of both anterior and posterior defects.
e anterior perineal hernia occurs almost exclusively in
women. e sac enters in front of the broad ligament and
lateral to the bladder, emerging anterior to the transversus
perinei musculature. e sac may pass between the ischiopubic bone and the vagina, thereby producing a swelling in
the posterior portion of the labia majus. Posterior perineal
hernias are found in both genders but remain more common in women. In men, the hernia sac emerges between
the bladder and the rectum to present as a bulge in the
perineum. In women, the hernia enters between the rectum
and the uterus to pass posteriorly to the broad ligament.
In this space, the hernia can push forward to present as a
bulge in the posterior vagina or emerge posteriorly into
the rectum. e hernia can pass through the levator ani
muscle or between it and the iliococcygeus muscle. A lateral pelvic hernia may occur through the hiatus of Schwalbe
when the levator ani muscle is not rmly attached to the
internal obturator fascia. is type of perineal hernia can
present anteriorly in the labium majus or posteriorly in the
ischiorectal fossa.
Clinical Manifestations
e patient with a perineal hernia most often complains of a
soft protuberance that is reduced in the recumbent position.
In cases of anterior perineal hernia, minor urinary retention
or discomfort may be reported. A soft bulge may be noted
in the posterior vagina or the labia, thereby interfering
with labor or intercourse. In posterior perineal hernias, the
patient may describe a mass protruding between the gluteus
muscles, thereby making sitting dicult after the hernia
has emerged in a standing position. e patient may rarely
complain of constipation or the feeling of incomplete defecation.
In general, symptoms from a perineal hernia are mild,
and strangulation is rare since the hernia defect in the pelvic
oor is large and surrounded by soft tissue and atrophied
musculature. Rectal prolapse may be confused with a posterior perineal hernia, although the two can exist concomitantly. e perineal hernia, even when the defect involves the
posterior pelvic oor, will present as a bulge anterior to the
prolapsed rectum.
Treatment
ree options for repair of the perineal hernia exist including
the transperitoneal, perineal, and the combined approaches.
e transperitoneal approach is the preferred method for
complete repair. In this technique, a lower midline abdominal
incision is performed and the bowel retracted out of the pelvis
with the patient in the Trendelenburg position. A defect in
the muscular lining of the pelvic oor will be noted, and any
remaining bowel in the defect can usually be easily reduced.
e sac is everted and excess sac tissue can be excised. While
small defects in the pelvic oor can be closed with interrupted
sutures of nylon or polypropylene, this is usually not an adequate repair given the poor strength of the atrophied tissue
that often surrounds the hernia defect. erefore, a repair
with a large piece of nonabsorbable mesh is preferred and
is usually tacked down to the pelvic oor tissues with interrupted nonabsorbable monolament sutures.
e perineal approach to hernia repair is more direct and
avoids a laparotomy but suers from inadequate exposure of
the actual hernia defect. In this technique, a transverse or longitudinal incision is made directly over the site of the hernia
bulge. e sac is identied and dissected free of its attachments to the surrounding pelvic musculature and fascia. e
sac is then excised and its contents are reduced within the
abdominal cavity. e defect is repaired with interrupted nonabsorbable suture, as the exposure is usually not wide enough
for proper placement of mesh. While this approach may be
suitable for a small hernia defect in an unhealthy patient, the
risk of recurrence is high.
In extraordinary cases in which the hernia contents cannot be reduced during a transperitoneal repair, a combined
approach with dissection from the perineum can be considered. e actual repair of the hernia defect should take place
from within the abdomen to obtain optimal exposure and
facilitate placement of mesh to reinforce the closure.
Postoperative perineal hernia repairs may also be
repaired by either a transperitoneal or perineal approach.
However, the transperitoneal approach is preferred in
this scenario, as the hernia contents may be dicult to
completely reduce secondary to postoperative adhesion
formation. In addition, given the previous operative
dissection, the pelvic oor is already weakened and mesh
placement is often necessary to achieve an adequate, tensionfree closure of the defect.
Chapter 7 Hernias 147
SPIGELIAN HERNIA
A spigelian hernia occurs along the semilunar line, which
traverses a vertical space along the lateral rectus border from
the costal margin to the pubic symphysis. Adriaan van der
Spieghel (1578–1625), a pupil of Fabricius of Padua and
a professor of anatomy and surgery, was the rst to accurately describe the semilunar line. He described the spigelian
fascia as the aponeurotic structure between the transversus
abdominis muscle laterally and the posterior rectus sheath
medially. is fascia is what makes up the semilunar line, and
it is through this fascial layer that a spigelian hernia forms.
Spigelian hernia is well described, and almost 1000 cases
have been reported in the medical literature. It is likely that
more of these hernias will be diagnosed, as the spigelian hernia is readily seen on computed tomography scans as well as
laparoscopic views of the anterior abdominal wall.
Anatomy
In practice, the semilunar line is taken as the lateral border of
the rectus sheath. Spieghel originally intended this structure to
represent the line of transition from the muscular bers of the
transversus abdominis muscle to the posterior aponeurosis of
the rectus. e semilunar line runs from the ninth rib cartilage
superiorly to the pubic tubercle inferiorly. e spigelian fascia
varies in width along the semilunar line, and it gets wider as it
approaches the umbilicus. e widest portion of the spigelian
fascia is the area where the semilunar line intersects the arcuate
line of Douglas (the linea semicircularis; Fig. 7-13). It is in this
region, between the umbilicus and the arcuate line, where more
37
than 90% of spigelian hernias are found.
It is thought that
since the spigelian fascia is widest at this point, it is also weakest in this region. Below the arcuate line, all of the transversus
abdominis aponeurotic bers pass anterior to the rectus muscle to contribute to the anterior rectus sheath, and there is no
posterior component of the rectus sheath. e rearrangement
of muscle and fascial bers at the intersection of the arcuate
and semilunar lines is thought to cause an area of functional
weakness that is predisposed to hernia formation. Hernias at
the upper extremes of the semilunar line are rare and usually
not true spigelian hernias since there is little spigelian fascia in
these regions.
As the hernia develops, preperitoneal fat emerges
through the defect in the spigelian fascia bringing an extension of the peritoneum with it (Fig. 7-14). e hernia usually meets resistance from the external oblique aponeurosis,
which is intact and does not undergo rearrangement of
A
FIGURE 7-13 Anatomy of the spigelian hernia and the sites of most
common occurrence.
B
C
D
FIGURE 7-14 e spigelian hernia. A. Breaching the spigelian
fascia. B. e most common type has passed through the transversus
abdominis and the internal oblique aponeuroses and is spreading out
in the interstitial layer posterior to the external oblique aponeurosis.
C. e less common type in the interstitial layer between the
transversus abdominis aponeurosis and the internal oblique muscle.
D. e least common subcutaneous type.
148 Part II Abdominal Wall
its aponeurotic bers at the arcuate line. For this reason,
almost all spigelian hernias are interparietal in nature, and
only rarely will the hernia sac lie in the subcutaneous tissues
anterior to the external oblique fascia. is fact makes the
accurate diagnosis of spigelian hernias more challenging.
e hernia also cannot develop medially due to resistance
from the intact rectus muscle and sheath. erefore, a large
spigelian hernia is most often found lateral and inferior
to its defect in the space directly posterior to the external
oblique muscle.
Clinical Manifestations
e patient most often presents with a swelling in the
middle to lower abdomen just lateral to the rectus muscle.
e patient may complain of a sharp pain or tenderness
at this site. e hernia is usually reducible in the supine
position. However, up to 20% of spigelian hernias will
present incarcerated, and for this reason operative repair is
mandatory once the hernia is conrmed on diagnosis. e
reducible mass may be palpable, even if it sits below the
external oblique musculature.
When the diagnosis is unclear, radiologic imaging may be
necessary. Ultrasound examination has been shown to be the
most reliable and easiest method to assist in the diagnostic
workup. Testa and colleagues found that abdominal wall ultrasonography was accurate in 86% of cases of spigelian hernia.
If the hernia is fully reduced during examination and no mass
is palpable, ultrasound evaluation can show a break in the
echogenic shadow of the semilunar line associated with the
fascial defect. Ultrasound can also identify the nonreduced
hernia sac passing through the defect in the spigelian fascia.
Computed tomographic scanning of the abdomen will also
conrm the presence of a spigelian hernia. As described above,
the anatomy of the spigelian hernia should make it readily
apparent on laparoscopic evaluation of the anterior abdominal
wall.
38
abdominis aponeuroses closes the fascial defect. Essentially,
this approximates the internal oblique and transversus fascia laterally to the rectus sheath medially. Prosthetic mesh is
not required for this repair, although the use of mesh plugs
to close the hernia defect has been described.
38
is uncommon and the operation is usually well tolerated.
LUMBAR HERNIA
e lumbar region is bordered by the twelfth rib superiorly,
the iliac crest inferiorly, the erector spinae muscles of the
back posteriorly, and a vertical line between the anterior tip
of the twelfth rib and the iliac crest anteriorly. e region
contains two anatomic triangles, through which the rare
lumbar hernia can form. e inferior lumbar triangle of Petit
is the more common of the two. Its anterior border is the
posterior edge of the external oblique muscle, the posterior
border is the anterior extent of the latissimus dorsi muscle,
and the inferior border is the iliac crest (Fig. 7-15). e anterior oor of the canal formed by this triangle is the lumbar fascia. Occasionally, the lower border of the latissimus
dorsi muscle overlaps the external oblique muscle, and in
this setting the triangle is absent. e superior lumbar triangle of Grynfeltt (see Fig.7-15) is deeper and is bounded
by the twelfth rib and the serratus posterior inferior muscle,
theposterior border of the internal oblique muscle, and by
the quadratus lumborum and erector spinae muscles posteriorly. e oor of the superior triangle is composed of
transversalis fascia and the entire triangular space is covered
posteriorly by the latissimus dorsi muscle.
Congenital lumbar hernias are rare, but case reports can
be found in the literature. Lumbar hernias most commonly
present in adults older than 50 years of age. Two-thirds of the
cases are reported in males, and left-sided hernias are thought
to be more common. Bilateral lumbar hernias have been
reported. Acquired lumbar hernias have been associated with
Recurrence
Treatment
e treatment for spigelian hernia is operative repair once
the diagnosis has been conrmed, given the risk for incarceration. is is usually performed under general anesthesia
given the need for splitting of the external oblique muscle.
Atransverse incision is made directly over the palpable mass
or fascial defect. A hernia in the subcutaneous space will
reveal itself immediately, and an interparietal hernia will
require further dissection. In this way, the external oblique
fascia is incised and the external oblique muscle is split to
identify the sac posterior to the muscle. e sac is freed
from its surrounding attachments until the neck is isolated.
e sac is opened, the intra-abdominal contents reduced,
and the sac is either excised if sizable or simply inverted
into the intra-abdominal cavity. Suturing the medial
and lateral edges of the internal oblique and transversus
FIGURE 7-15 e anatomy of the lumbar hernia illustrating the
superior and inferior lumbar triangles.
Chapter 7 Hernias 149
back or ank trauma, poliomyelitis, back surgery, and the use
of the iliac crest as a donor site for bone grafts.
Strangulation is rare in lumbar hernias since at least two of
the three boundaries for the hernia defect are soft and muscular in origin. e hernia tends to increase in size over time
and may assume large proportions and overhang the iliac
crest. Symptoms range from a vague dullness in the ank or
lower back to focal pain associated with movement over the
site of the defect. On physical examination, a soft swelling
in the lower posterior abdomen will be found that is usually reducible without diculty. e hernia will increase in
size with straining or a standard Valsalva maneuver. Ultrasonographic or computed tomographic imaging is usually
obtained in the patient with a suspected lumbar hernia to
conrm the diagnosis.
Operative repair of the lumbar hernia is performed with
the patient under general anesthesia and in a modied lateral
decubitus position. A kidney rest can be used to widen the
lumbar space between the twelfth rib and iliac crest. An oblique
skin incision is made in the region of the hernia and the sac is
identied. e dissection may require takedown of the latissimus dorsi muscle to reach the deeper superior lumbar triangle.
FIGURE 7-16 e superior and inferior sciatic foramina and the
direction of sciatic hernias.
Once the sac is identied, it is opened and the contents are
carefully reduced. e empty sac can then be inverted or simply excised. While complicated procedures for lumbar hernia
closure utilizing muscle aps and grafts have been described, a
small defect surrounded by healthy tissue can usually be closed
primarily with an interrupted or continuous layer of nylon or
polypropylene suture. If a large defect is found or the tissues
appear weak, the hernia may be repaired with a large sheet of
prosthetic nonabsorbable mesh placed between the peritoneal
layer and the abdominal wall musculature. To prevent migration, the mesh is usually xed to the peripheral tissues by a
series of interrupted nonabsorbable sutures.
Recently, minimally invasive approaches to repair of lumbar
hernias have been reported. ese involve either intraperitoneal
laparoscopy necessitating takedown of the lateral peritoneal
reection of the colon to facilitate exposure of the hernia defect,
39
or retroperitoneoscopy in which the lateral retroperitoneal space
40
is entered and insuated.
Initial results with the minimally
invasive approaches are encouraging, although these case series
contain small numbers of subjects.
e hernia sac passes laterally, inferiorly, and ultimately
posteriorly to lie deep to the gluteus maximus muscle. While
case reports of this rare hernia exist in the pediatric age
group, the majority of sciatic hernias are found in the adult
population. e patient complains of pain deep in the buttock that may radiate down the leg in the sciatic nerve distribution. Alternatively, the patient may report a lump in the
buttock or infragluteal area that is painful and tender. Rarely,
ureteral obstruction occurs because the ipsilateral ureter is
contained within the hernia contents. Physical examination
often reveals a reducible mass deep to the gluteus maximus,
although the actual hernia defect is rarely palpable given the
anatomic depth and the thickness of the buttock musculature. Incarceration of the hernia can occur, and sciatic hernia
has been known to present with bowel obstruction.
e treatment of a sciatic hernia is surgical. Both transperitoneal and transgluteal approaches have been described
in depth, and the transperitoneal technique is preferred in the
setting of bowel obstruction or incarceration. Rarely, a combined approach will be necessary to fully reduce the hernia
SCIATIC HERNIA
contents. Even in the setting of incarceration, the bowel can
usually be reduced from within the hernia with gentle trac-
A sciatic hernia is dened as a protrusion of peritoneum and
intra-abdominal contents through the greater or lesser sciatic
notch (Fig. 7-16). e greater sciatic notch is traversed by the
piriformis muscle, and hernia sacs can protrude either superior
or inferior to this muscle. ere are classically three variants of
the sciatic hernia that are dened by their anatomic site of exit
from the pelvis. e suprapiriform defect is by far the most
common and is thought to represent 60% of cases of sciatic
hernia. Infrapiriform hernias are found in approximately 30%
of cases, and subspinous hernias (through the lesser sciatic
foramen) occur in 10% of cases.
tion. When necessary with the transperitoneal approach,
the defect can be dilated with manual manipulation or the
piriformis muscle may be partially incised. Full visualization
of the structures is necessary and great care must be taken
to avoid injury to the many nerves and vessels found in this
region. After the sac has been excised, the defect is repaired
using interrupted nonabsorbable suture or a prosthetic mesh
plug or patch for larger hernia defects.
e posterior or transgluteal technique can be utilized for
uncomplicated, reducible sciatic hernias diagnosed preoperatively.
With this method the patient is placed in the prone position.
150 Part II Abdominal Wall
e gluteus maximus muscle is approached through a gluteal
incision starting at the posterior edge of the greater trochanter
and is detached at its origin to expose the hernia defect. is
exposure allows visualization of the piriformis muscle, the gluteal
vessels and nerve, and the sciatic nerve. e sac is then isolated
and opened. Following reduction of the hernia contents, the
defect can be sutured closed using large nonabsorbable suture or
repaired with a prosthetic mesh.
POSTOPERATIVE VENTRAL WALL
(INCISIONAL) HERNIA
A postoperative ventral abdominal wall hernia, more
commonly termed incisional hernia, is the result of a failure
of fascial tissues to heal and close following laparotomy.
Such hernias can occur after any type of abdominal wall
incision, although the highest incidence is seen with mid-
41
line and transverse incisions.
Postoperative ventral hernias
following paramedian, subcostal, McBurney, Pfannenstiel,
and ank incisions have also been described in the literature.
Laparoscopic port sites may also develop hernia defects in the
abdominal wall fascia.
As the approximated fascial tissue separates, the bowel
and omentum herniate through the opening, covered by a
peritoneal sac. ese hernias can increase in size to enormous
proportions, and giant ventral hernias can contain a signicant amount of small or large bowel. At the extreme end of
the ventral hernia spectrum is the giant incisional hernia that
leads to loss of the abdominal domain, which occurs when
the intra-abdominal contents can no longer lie within the
abdominal cavity.
Incidence and Etiology
Incisional hernias have been reported in up to 20% of patients
undergoing laparotomy. Modern rates of incisional hernia
range from 2% to 11%.
100,000 ventral incisional hernia repairs are performed each
year in the United States alone. e incidence seems to be
lower in smaller incisions so that laparoscopic port site hernias are much less common than hernias following large
midline abdominal incisions. While it was once believed that
the majority of incisional hernias presented within the rst
12 months following laparotomy, longer-term data indicate
that at least one-third of these hernias will present 5–10 years
postoperatively.
Multiple risk factors exist for the development of an incisional hernia. Some of these risks are under the control of
the surgeon at the initial operation, while many others are
patient specic or related to postoperative complications.
Patient-specic risks for postoperative ventral hernia include
advanced age, malnutrition, presence of ascites, corticosteroid
use, diabetes mellitus, cigarette smoking, and obesity.
Emergency surgery is known to increase the risk of incisional
42–44
It is estimated that approximately
41,45–47
hernia formation. Wound infection is believed to be one of
the most signicant prognostic risk factors for development
41,48
of an incisional hernia.
It is for this reason that many
surgeons advocate aggressive and early opening of the skin
closure to drain any potential infection at the fascial level.
Postoperative sepsis has also been identied as a risk for subsequent incisional hernia.
Technical aspects of wound closure likely contribute to
incisional hernia formation. Wounds closed under excessive
tension are prone to fascial closure disturbance. erefore,
a continuous closure is advocated to disperse the tension
throughout the length of the wound. In this way, 1 cm bites
of fascia on either side of the incision are taken with each pass
of the suture and the suture is advanced 1 cm at a time along
the length of the incision. e type of incision may aect hernia formation. Studies have shown that transverse incisions
are associated with a reduced incidence of incisional hernia
compared to midline vertical laparotomies, although the data
are far from conclusive.
46,49
Clinical Manifestations
e patient with an incisional hernia will complain of a bulge
in the abdominal wall originating deep to the skin scar. e
bulge may cause varying degrees of discomfort or may present
as a cosmetic concern. Symptoms will usually be aggravated
by coughing or straining as the hernia contents protrude
through the abdominal wall defect. In large ventral hernias,
the skin may present with ischemic or pressure necrosis leading to frank ulceration. Presentation of the incisional hernia
with incarceration causing bowel obstruction is not uncommon. is may be associated with a history of repeated mild
attacks of colicky dull abdominal pain and nausea consistent
with incomplete bowel obstruction.
On examination the hernia is usually easy to identify
and the edges of the fascial defect can often be dened by
palpation. e entire abdominal wall along the length of the
incision should be inspected and palpated carefully, as multiple hernias are often present in the setting of an incisional
hernia. In the obese patient with a suspected incisional hernia that cannot be conrmed on examination, computed
tomography of the abdomen is the best way to visualize
intra-abdominal contents within the hernia sac. In extreme
instances, laparoscopy may be required to diagnose a hernia
defect that only intermittently contains intra-abdominal
contents.
Treatment
e treatment of ventral incisional hernia is operative repair,
and three general classes of operative repair have emerged in
the modern era. ese techniques include primary suture
repair of the hernia, open repair of the hernia with prosthetic
mesh, and laparoscopic incisional hernia repair. e major
sequela from operative repair of the incisional hernia is hernia
Chapter 7 Hernias 151
recurrence, and there are convincing data that placement of
mesh to repair the hernia defect has decreased the high recurrence rate historically associated with primary suture repair to
50,51
less than 25%.
that laparoscopic incisional hernia repair will have the lowest
Many advocates of the operation believe
A
rate of hernia recurrence and denitive studies are underway
to assess this question.
In general, primary repair of incisional hernias can be performed for hernia defects less than 4 cm in diameter with
strong, viable surrounding tissue. For larger hernias or hernias associated with multiple small defects, mesh repair is
indicated. Even with mesh repair, hernia recurrence remains a
signicant complication. In one multicenter trial, for example,
200 patients were randomly assigned to suture or mesh repair
of a primary hernia or a rst recurrence of hernia at the site
52
ofa vertical midline incision.
e 3-year cumulative rates of
B
recurrence among patients who had suture or mesh for repair
of a primary hernia were 43% and 24%, respectively. e rates
of second recurrence were 58% and 20%, respectively.
PRIMARY SUTURE REPAIR
e operation is best performed with the patient under general anesthesia to achieve full relaxation of the abdominal wall
musculature. e skin is opened through the previous incision and dissection is performed through the subcutaneous
C
tissues. Care should be taken as the level of the anterior rectus
sheath is approached since portions of the sac and its contents
may lie at this level. e sac is identied and cleared of its
attachments to the fascia using electrocautery. In this way,
any peritoneal attachments to the anterior abdominal wall in
the vicinity of the hernia are taken down and the sac is fully
reduced into the abdominal cavity. e fascia is then cleared
of soft tissue both anteriorly and posteriorly for at least a 3–4
FIGURE 7-17 Separation of components of the abdominal wall to
mobilize the fascia toward the midline.
cm margin. is allows for a margin of healthy fascia to bring
together in the midline with suture closure.
e fascia is then closed using an interrupted layer of
nonabsorbable suture by taking large bites of the clean fascia
on both sides of the defect. e sutures are usually placed
sequentially and then tied after the entire layer of suture has
been placed. e fascia is then inspected to conrm that no
additional defects are present and that the repair sutures are
not pulling through the tissue due to excessive tension. e
skin is closed over the fascia using either staples or a running
subcuticular layer. If the hernia contents have created a large
pocket in the soft tissue above the anterior fascia, placement
of a closed suction drain for evacuation of early seroma uid
can be considered.
If there is tension upon attempted closure of the abdominal wall, a separation of components can be performed in
order to mobilize the fascia toward the midline (Fig. 7-17).
is technique begins with the mobilization of the skin and
soft tissue o of the underlying fascia. e fascia of the external oblique is then incised lateral to the rectus abdominis
and the external oblique is dissected free from the internal
oblique in a relatively avascular plane. is alone allows
for signicant mobilization of the abdominal wall toward
the midline. Should additional mobilization be required,
the posterior rectus sheath can be incised in a longitudinal
fashion to allow the overlying rectus abdominis and anterior
53
rectus sheath to slide even further toward the midline.
is
technique allows for closure of complex or infected abdominal wounds without the need for implantation of any foreign
material.
Over the last 10–15 years, the introduction of component separation as a method for repairing ventral hernias has
gained increasing popularity due to its conceptual purity and
its overwhelming success. Recent series including those by
54
has reported his experience in 200 patients who under-
Ko
went this procedure over the course of slightly over 1 decade.
e overall recurrence rate was 21%. Supportive polypropylene mesh was employed to cover the defect. In the process of
performing this procedure, bilateral releases of the external
oblique muscle are performed and the fascia is mobilized,
thereby allowing medial movement of the rectus muscle.
is brings the rectus muscle closer to the midline and
achieves a muscular closure of the midline which can be reinforced or strengthened by the placement of either biologic or