ABDOMINAL HERNIA CLASSIFICATION ETIOLOGY AND PATHOGENESIS CLINICAL PRESENTATION PRINCIPELS OF SURGICAL TREATMENT COMPLICATIONS

DANYLO HALYTSKY LVIV NATIONAL MEDICAL UNIVERSITY
DEPARTMENT OF SURGERY #1
SURGICAL TREATMENT. COMPLICATIONS
LVIV – 2019
Approved at the meeting of the surgical methodological commission of Danylo
Halytsky Lviv National Medical University (Meeting report 56 on May 16, 2019)
Guidelines prepared:
GERYCH Igor Dyonizovych – PhD, professor, head of Department of Surgery
#1 at Danylo Halytsky Lviv National Medical University
VARYVODA Eugene Stepanovych – PhD, associate professor of Department of
Surgery #1 at Danylo Halytsky Lviv National Medical University
STOYANOVSKY Igor Volodymyrovych – PhD, assistant professor of
Department of Surgery #1 at Danylo Halytsky Lviv National Medical University
CHEMERYS Orest Myroslavovych – PhD, assistant professor of Department of
Surgery #1 at Danylo Halytsky Lviv National Medical University
Referees:
General Surgery at Danylo Halytsky Lviv National Medical University
OREL Yuriy Glibovych - PhD, professor of Department of General Surgery at
Danylo Halytsky Lviv National Medical University
Responsible for the issue first vice-rector on educational and pedagogical affairs at
Danylo Halytsky Lviv National Medical University, corresponding member of
National Academy of Medical Sciences of Ukraine, PhD, professor M.R. Gzegotsky
I. Background
A hernia is an abnormal protrusion of a viscus or part of a viscus through a
defect either in the containing wall of that viscus or within the cavity in which the
viscus normally is situated. In abdominal hernias, the ‘wall’ refers to the anterior and
posterior muscle layers of the abdomen, the diaphragm, and the walls of the pelvis.
Hernias are composed of a sac, the parts of which are described as the neck,
body and fundus, and the hernial contents. The sac consists of peritoneum which
protrudes through the abdominal wall defect or ‘hernial orifice’, and envelopes the
hernial contents. The neck of the sac is situated at the defect. Hernias with a narrow
or rigid neck are more likely to obstruct and strangulate. The body is the widest part
of the hernial sac, and the fundus is the apex or furthest extremity. Viscera most
likely to enter a hernial sac are those normally situated in the region of the defect and
those which are mobile, namely the omentum, small intestine and colon. Some
hernial contents have been ascribed generic names.
II. Learning Objectives
1. To study the etiological factors of disease, classification of hernias, clinical
signs, diagnostic methods, treatment and complications (α = I).
2. To know the main causes of the disease, typical clinical course and
complications, diagnostic value of laboratory and instrumental methods of
examination and the principles of the modern conservative and surgical treatment (α
= II).
3. To be able to collect and analyze the complaints and disease history,
thoroughly perform physical examination, determine the order of the most
informative examination methods and perform their interpretation, establish clinical
diagnosis, justify the indications for surgery, choose adequate method of surgical
intervention (α = III).
4. To develop creativity in solving complicated clinical tasks in patients with
atypical clinical course or complications of hernias (α = V).
III. Purpose of personality development
Development of professional skills of the future specialist, study of ethical and
deontological aspects of physicians job, regarding communication with patients and
colleagues, development of a sense of responsibility for independent decision
making. To know modern methods of treatment of patients with hernias and its
complications.
Previous subjects
investigation in patients
pancreatitis
Robson’s signs
cholecystitis
3. Peptic ulcer of
perforation
bowel obstruction
colic
Classification of hernias due to International Classification of Diseases
1. Inguinal hernia (code K 40).
2. Femoral hernia (code K 41).
3. Umbilical hernia (code K 42).
4. Abdominal wall hernia (code K 43).
5. Diaphragmatic hernia (code K 44).
6. Other hernia of abdominal cavity (code K 45).
7. Unspecified hernia of the abdominal cavity (code K 46).
Richter’s hernia
Only part of the circumference of the bowel (usually the anti-mesenteric
border) is trapped within the hernial sac. The herniated part may become ischaemic.
Because the lumen of the bowel is not occluded, intestinal obstruction does not occur,
and there are few symptoms until the ischaemic part perforates.
Littre’s hernia
A Meckel’s diverticulum lies within the hernial sac. Littr´e’s hernia occurs
most commonly in a femoral or inguinal hernia.
Maydl’s hernia
The hernial sac contains two loops of intestine. The loop of intestine within the
abdominal cavity may become obstructed or strangulated, and this may not be
recognised unless the hernial contents are inspected and returned to the abdominal
cavity (‘reduced’) completely.
Predisposing factors
A hernia occurs because of (a) weakness or defect in the abdominal wall, and
(b) positive intra-abdominal pressure (IAP) (which is often raised) forces the viscus
into the defect.
Sites of weakness in the abdominal wall
Weaknesses in the abdominal wall may be:
- Congenital (i.e. present at birth) – e.g. patent processus vaginalis or canal
of Nuck, posterolateral or anterior parasternal diaphragmatic defect, patent
umbilical ring in children.
- Where a normal anatomical structure passes through the abdominal wall –
e.g. oesophageal hiatus, umbilical ligament in adults, obturator foramen,
sciatic foramen.
- Acquired – e.g. surgical scar, site of an intestinal stoma, muscle wasting
with increasing age, fatty infiltration of tissues because of obesity.
Increased intra-abdominal pressure
Raised intra-abdominal pressure (IAP) stretches the abdominal vertically and
horizontally, thereby increasing the circumference of any defect. Also, high IAP
forces abdominal contents through a defect. Sudden or sustained increases in IAP are
due to several causes:
- Pregnancy and childbirth
- Obesity
- Ascites
- Gross organomegaly
strangulation.
Irreducibility
A hernia is ‘irreducible’ when the sac cannot be emptied completely of
contents. Irreducibility is caused by (i) adhesions between the sac and its contents, (ii)
fibrosis leading to narrowing at the neck of the sac, or (iii) a sudden increase in IAP
that causes transient stretching of the neck and forceful movement into the sac of
contents, which cannot subsequently return to their original location.
Generally, irreducible hernias should be operated on soon after presentation.
Although irreducibility is not an indication for urgent operation, it is the step before
obstruction supervenes. In addition, irreducible hernias are usually painful.
Obstruction
A hernia becomes obstructed when the neck is sufficiently narrow to occlude
the lumen of the intestine contained within the sac. Obstructed hernias are nearly
always irreducible and, if not treated, may become strangulated. Often, there is a
history of a sudden increase in IAP that has pushed intestine or other contents into the
sac. The patient presents with symptoms and signs of intestinal obstruction
(abdominal colic, vomiting, constipation, abdominal distension), together with a
tender irreducible hernia. Failure to examine the hernia orifices in a patient with
intestinal obstruction may lead to the wrong operative approach being undertaken. It
may be difficult to distinguish obstruction from strangulation on clinical grounds, and
therefore obstructed hernias should be treated as a matter of urgency.
Strangulation
Strangulation means that the blood supply of the contents has ceased due to
compression at the hernial orifice. Initially, lymphatic and venous channels are
obstructed, leading to oedema and venous congestion but with continued arterial
inflow. When the tissue pressure equals arterial pressure, arterial flow ceases and
tissue necrosis ensues. Strangulation is a serious complication and, if the intestine is
involved, leads to peritonitis which can be fatal. A strangulated hernia is both
irreducible and obstructed, and is very tense and usually exquisitely tender. Erythema
of the overlying is a late sign. Strangulated hernias must be operated on urgently. A
strangulated Richter’s hernia is not preceded by intestinal obstruction and there
maybe few local signs.
Inguinal hernia
Inguinal hernia is the commonest hernia, and is approximately10 times more
common in males than females. Two types of inguinal hernia (IH) are recognised,
indirect (IIH) and direct DIH), but they can occur together.
Anatomy of Inguinal Canal
Several structures course within the inguinal canal and require familiarity to
avoid iatrogenic injury during herniorraphy. The canal contains the spermatic cord in
males and the round ligament of the uterus in females. The canal lies obliquely
between the internal or deep inguinal ring, derived from transversalis fascia, and the
external or superficial inguinal ring, derived from external oblique aponeurosis. The
spermatic cord courses from the internal ring through the inguinal canal and exits
through the external ring to join the testicle within the scrotum. The spermatic cord
contains multiple structures including the superficial spermatic fascia, derived from
Camper’s and Scarpa’s fascia; the external spermatic fascia, derived from external
oblique muscle; a circumferential layer of cremaster muscle, derived from internal
oblique muscle; the cremasteric or external spermatic artery; the internal spermatic
fascia, derived from transversalis fascia; the vas deferens and arteries to the vas
deferens; the testicular or internal spermatic artery, which arises from the aorta just
inferior to the renal arteries; the pampiniform venous plexus, which coalesces into the
testicular veins and drains into the inferior vena cava on the right and the renal vein
on the left; the ilioinguinal nerve; the genital branch of the genitofemoral nerve; and
sympathetic fibers from the hypogastric plexus. The inguinal canal can be defined by
its borders. The inguinal canal is bound anteriorly by the external oblique
aponeurosis, superiorly by internal oblique and transversus abdominis muscles and
aponeuroses, and inferiorly by the inguinal and lacunar ligaments. The posterior wall
or floor is formed by transversalis fascia. A defect in this layer may allow peritoneum
and the contents of the abdominal cavity to herniate. Hesselbach’s triangle is formed
by the inguinal ligament laterally, the rectus sheath medially, and the inferior
epigastric vessels superiorly.
Indirect inguinal hernia
The hernial sac of an IIH is a patent processus vaginalis, and the neck of the
sac is situated at the deep inguinal ring, lateral to the inferior epigastric artery. The
sac accompanies the spermatic cord along the inguinal canal towards the scrotum for
a varying distance. The sac lies in front of the cord and is enclosed by the coverings
of the cord. Except in children and infants, the essential cause of an IIH is (a) failure
of the processus vaginalis to become completely obliterated to form the ligamentum
vaginale, which normally occurs within a few days after birth, and (b) loss of
integrity of the inguinal canal (see above). Even though the sac of an IIH is
congenital, herniation may not occur until later in life, when there is failure of the
normal mechanisms that maintain the inguinal canal. The incidence of IIH is
approximately 800–1000 per million male population. Indirect IHs are approximately
four times more common than DIH, occur at any time during life, and have a male to
female ratio of about 10:1.
Classification of indirect inguinal hernias
Indirect IHs are classified according to the length of the hernial sac:
- Bubonocele – the sac is confined to the inguinal canal.
- Funicular – the sac extends along the length of the inguinal canal and
through the superficial inguinal ring, but does not extend to the scrotum or
labium majora.
- Complete, scrotal or inguinoscrotal – the sac passes through the inguinal
canal and superficial inguinal ring and extends into the scrotum or labium.
Direct inguinal hernia
A DIH protrudes directly through the posterior wall of the inguinal canal,
medial to the inferior epigastric artery and deep inguinal ring. The essential fault with
a DIH is weakness of the inguinal canal, and is invariably associated with poor
abdominal musculature. Herniation occurs at a site where the transversalis fascia is
not supported by the conjoint tendon or the transversus aponeurosis, an area known
as Hesselbach’s triangle. The neck of a DIH is usually larger than the body and so
strangulation is rare. The hernia passes forwards as it enlarges, stretching muscle and
fascial layers. It rarely reaches a large size or approaches the scrotum. Occasionally,
the inferior epigastric vessels straddle the hernia which is then known as a ‘pantaloon
hernia’.
Direct IH is rare in females and does not occur in children. It is more common
on the right side after appendicectomy, suggesting that damage to the iliohypogastric
and ilio-inguinal nerves with subsequent weakness of the internal oblique and
transversus abdominis muscles is an aetiological factor.
Clinical features of inguinal hernias
Inguinal hernias present with inguinal discomfort, with or without a lump.
Discomfort is due to stretching of the tissues of the inguinal canal and occurs
typically when IAP is increased. Pain may also be referred to the testis because of
pressure on the spermatic cord and ilio-inguinal nerve. Severe inguinal or abdominal
suggests obstruction or strangulation. A lump is usually obvious to the patient, is
often precipitated by increasing IAP, and may reduce completely with rest and lying
down.
The patient initially is examined standing to demonstrate the lump and possible
cough impulse, and then lying down to allow the hernia to be reduced. An IIH
protrudes along the line of the inguinal canal for a variable distance towards the
scrotum or labia; a DIH appears as a diffuse bulge at the medial end of the inguinal
canal. The significance of a ‘cough impulse’, or sudden bulging of the inguinal region
with coughing, must be interpreted carefully. A generalised weakness in the inguinal
region will result in a diffuse bulge appearing with coughing, but this condition
(known as a Malgaigne’s bulge) is not the same as a hernia in which the cough
impulse is discrete and confined to the area of herniation. Abdominal examination is
performed to detect organomegaly, a mass or ascites.
Indirect or direct inguinal hernia?
An IIH is prevented from appearing by applying pressure over the deep
inguinal ring (which lies just above the midpoint of the inguinal ligament) because an
IIH protrudes through the deep inguinal ring. A DIH protrudes through the posterior
wall of the inguinal canal medial to the deep ring. IIH and DIH may be distinguished
by firstly reducing the hernia by gently it upwards and laterally. Then, the index and
middle fingers are placed firmly over the surface marking of the deep ring and the
patient is asked to cough. If the hernia is controlled by pressure over the deep ring,
then it is presumed to be indirect. If the hernia appears medial to the examiner’s two
fingers, then it is direct.
Accurate distinction of an IIH from a DIH may not possible because of slight
variation in the position of the deep inguinal ring. However, an attempt should made
to distinguish between the two because IIHs are more likely to complications and
should be repaired sooner rather than later.
Sliding inguinal hernia
A sliding inguinal hernia is a variant in which part of a viscus (usually the
colon) is adherent to the outside of the peritoneum forming the hernial sac beyond the
hernial orifice. Thus, the viscus and the hernia sac, which may contain another
abdominal viscus, lie within the inguinal canal. Sliding hernias are more common on
the left side (where they contain part of the sigmoid colon) than on the right (where
they contain part of the caecum). Sliding hernias occasionally contain part of the
bladder or an ovary and ovarian tube. A sliding hernia may be indirect or direct. They
are nearly always found in males. A sliding hernia should be suspected if the neck of
the hernia is bulky, or if the hernial sac does not separate easily from the cord at
operation.
REPAIRS
Anterior approaches
The goal of all repairs is to close the myofascial defect through which the
hernia protrudes. This closure can be done from a number of approaches with or
without placement of a prosthetic mesh. The classic tissue repairs use permanent
suture to reinforce the internal inguinal ring and the floor of the inguinal canal and do
not employ the use of a prosthesis. These techniques include the Marcy, Bassini,
Shouldice, and McVayrepairs. The Lichtenstein repair uses prosthetic mesh, as does
the plug technique. Common to all these methods is the anterior dissection of the
inguinal canal and hernia sac, followed by a myofascial repair, and closure of the
canal. The basic technique of inguinal canal and sac dissection is the same for all
anterior approaches, whereas the repair of the myofascial defect differs. After
incising and dividing the layers of the anterior abdominal wall to expose the inguinal
canal, the spermatic cord is isolated at the level of the pubic tubercle, and mobilized
to the level of the internal ring. The cord is then dissected by dividing cremasteric
muscle fibers to identify an indirect sac, if present. The sac is usually found on the
anteromedial side of the cord. The sac is opened and its contents reduced back into
the abdominal cavity. The sac is ligated at its base with a pursestring suture and
amputated. If an indirect sac extends inferiorly beyond the pubic tubercle, the distal
sac should simply be divided and left open. If a direct hernia sac is identified, it
generally should not be operated but should be reduced bluntly back into the
abdominal cavity and imbricated with one or more sutures placed superficially in the
transversalis fascia. This maneuver effectively avoids injury to any organs such as the
colon or bladder, which may form a sliding component in a direct hernia.
Marcy repair
The Marcy repair refers to a high ligation of the sac and closure of the internal
inguinal ring along its medial aspect, displacing the cord laterally. This technique can
be used only to repair indirect inguinal hernias, and its main utility is in pediatric
patients or in adults (especially women) with a small indirect hernia and minimal
damage to the internal ring. Patients with a direct inguinal hernia require the addition
of another type of repair.
Bassini repair After a complete and deliberate dissection of the inguinal canal, the floor is
reconstructed by approximating the internal oblique muscle, the transversus
abdominis muscle, and the transversalis fascia (the Bassini triple layer) with the
iliopubic tract and shelving edge of the inguinal ligament using interrupted sutures.
This repair may be used for both indirect and direct inguinal hernias.
Shouldice repair This technique is remarkably similar to the Bassini operation in that the layers
approximated to reconstruct the inguinal canal floor are the same for both. However,
the Shouldice technique uses a series of running sutures to imbricate the
reconstruction into several layers. As in the Bassini operation, the cord is mobilized,
the cremaster muscle is divided, a high ligation of the sac is performed, and the
transversalis fascia forming the floor of the inguinal canal is incised. The floor is
reconstructed by placing a series of running sutures to approximate the lateral edge of
the rectus abdominis muscle near the pubic tubercle, the internal oblique muscle, the
transverses abdominis muscle, and the transversalis fascia to the iliopubic tract and
the shelving edge of the inguinal ligament.
McVay (Cooper’s Ligament) repair
The McVay repair approximates the transversus abdominis arch to Cooper’s
ligament, the iliopubic tract, and the inguinal ligament. The McVay repair may be
used for inguinal and femoral hernias.
Lichtenstein repair The Lichtenstein approach is a tension-free method that uses prosthetic mesh to
reinforce the transversalis fascia forming the canal floor without attempting to use
any attenuated native tissues in the repair .Polypropylene mesh is trimmed to extend
4 cm lateral to the internal ring and 2 cm medial to the public tubercle, and is then
secured to the inguinal ligament laterally and the lateral edge of the rectus sheath and
internal oblique muscle and aponeurosis medially using permanent monofilament
suture. Local anesthesia maybe used, and several studies have shown that this repair
enables a quicker return to work, is associated with less postoperative pain, and has
fewer recurrences than tissue repairs. The Lichtenstein repair may be used for direct
and indirect inguinal hernias but does not address femoral hernias. Given the results
of…