Hernia 1

د.توفيق جاسم

المرحلة الرابعة/الجراحة العامة
كلية طب الكندي/جامعة بغداد
2014-2015
Hernias, umbilicus and abdominal wall

A hernia is a protrusion of a viscus or part of a viscus through an abnormal opening in the wall of its containing cavity (or as defined in 1804 by astley cooper as a protrusion of any viscus from its proper cavity)-.
The external abdominal hernia is the most common form, the most frequent varities being the inguinal,femoral and umbilical (75%). Other less common varities are epigastric and divarication of the recti. Other rare forms are spigelian, obturator, lumbar (superior&inferior), gluteal& siatic.

Abdominal hernias are classified as either abdominal wall or groin hernias.

Abdominal wall hernias include umbilical hernias, epigastric hernias, Spigelian hernias, and incisional (ventral) hernias. Umbilical hernias (protrusions through the umbilical ring) are mostly congenital, but some are acquired in adulthood secondary to obesity, ascites, pregnancy, or chronic peritoneal dialysis. Epigastric hernias occur through the linea alba. Spigelian hernias occur through defects in the transversus abdominis muscle lateral to the rectus sheath, usually below the level of the umbilicus. Incisional hernias occur through an incision from previous abdominal surgery.
Groin hernias include inguinal hernias and femoral hernias. Inguinal hernias occur above the inguinal ligament. Indirect inguinal hernias traverse the internal inguinal ring into the inguinal canal, and direct inguinal hernias extend directly forward and do not pass through the inguinal canal. Femoral hernias occur below the inguinal ligament and go into the femoral canal.
General features common to all hernias
Symptoms and Signs
The diagnosis is clinical. Because the hernia may be apparent only when abdominal pressure is increased, the patient should be examined in a standing position. If no hernia is palpable, the patient should cough or perform a Valsalva maneuver as the examiner palpates the abdominal wall. Examination focuses on the umbilicus, the inguinal area (with a finger in the inguinal canal in males), the femoral triangle, and any incisions that are present.

Most patients complain only of a visible bulge, which may cause vague discomfort or be asymptomatic. Most hernias, even large ones, can be manually reduced with persistent gentle pressure; placing the patient in the Trendelenburg position may help. An incarcerated hernia cannot be reduced but has no additional symptoms.
A strangulated hernia causes steady, gradually increasing pain, typically with nausea and vomiting. The hernia itself is tender, and the overlying skin may be erythematous; peritonitis may develop depending on location, with diffuse tenderness, guarding, and rebound.


Aetiology
Any condition that raises intra-abdominal pressure, such as a powerful muscular effort, may produce a hernia. Chronic cough, straining on micturition or straining on defecation may predispose to a hernia in an adult. Whooping cough is a predisposing cause in childhood. Hernias are more common in smokers. It should be remembered that the appearance of a hernia in an adult can be a sign of intra-abdominal malignancy.
Stretching of the abdominal musculature because of an increase in contents, as in obesity, can be another factor. Fat acts to separate muscle bundles and layers, weakens aponeuroses and favours the appearance of paraumbilical, direct inguinal and hiatus hernias.
A femoral hernia is rare in men and nilliparous women but more common in multiparous women due to stretching of the pelvic ligaments.
So the causes of hernias are;
Coughing
Straining
Obesity
Intra-abdominal malignancy
Powerful muscular effort
Pregnancy
ascitis
Chronic peritoneal dialysis

Composition of a hernia

The sac
The sac is a diverticulum of peritoneum consisting of mouth, neck, body and fundus. The neck is usually well defined, but in some direct inguinal hernias and in many incisional hernias there is no actual neck. The diameter of the neck is important because strangulation of bowel is a likely complication where the neck is narrow as in femoral and paraumbilical hernias
The body is not necessarily occupied. In infancy and childhood, the sac is thin . in long standing cases, the wall of the sac may be comparatively thick.

The covering

Coverings are derived from the layers of the abdominal wall through which the sac passes. In long standing cases , they become atrophied and amalgamated with each others


Contents
These can be;
Omentum=omentocele
Intestine=enterocele. More commonly small bowel but may be large bowel or appendix
A portion of the circumference of the intestine=Richter,s hernia
A portion of the bladder(or a diverticulum) may constitute part or to be the sole contents of a direct inguinal, a sliding inguinal or a femoral hernia
Ovary with or without the corresponding Fallopian tube
A mickels diverticulum= a littre,s hernia
Fluid. As part of ascitis
Classification
Reducible; contents can be returned to abdomen
Irreducible; contents cannot be returned but there are no other complications
Obstructed; bowel in the hernia has good blood supply but its obstructed
Strangulated; blood supply of bowel is obstructed
Inflamed; contents of sac have become inflamed

Reducible hernias

The hernia either reduces itself when the patient lies down or can be reduced by the patient or the surgeon. The intestine usually gurgles on reduction and the first portion is more difficult to reduce than the last. Omentum, in contrast, is douphy and the last portion is more difficult to reduce than the first. A reducible hernia imparts an expansile cough impulse

Irreducible hernia

The contents cannot be returned to the abdomen but no evidence of other complications. It is usually due to adhesions between the sac and its contents or from overcrowding within the sac. Irreducibility without complication is almost diagnostic of an omentocele in femoral or umbilical hernias


Obstructed hernia
There is an irreducible hernia containing intestine which is obstructed but there is no interference to the blood supply. There will be colicky abdominal pain and tenderness over the hernia which is less sever and more gradual than is the case in strangulation. Usually there is no clear distinction clinically between obstruction and strangulation

Incarcerated hernia

Portion of the colon occupying a hernia sac is blocked with faeces,so a loop of intestine become stuck in the hernia, the contents of the bowel should be capable of being indented with the finger, like putty

Strangulated hernia

A hernia becomes strangulated when the blood supply of its contents(the trapped portion) is seriously impaired, rendering the contents ischaemic. Gangrene may occur as early as 5-6 hours after the onset of first symptoms. . With gangrene, the intestinal wall dies, usually causing rupture, which leads to peritonitis (inflammation and usually infection of the abdominal cavity), shock, and, if untreated, death.
Although inguinal hernia may be 10 times more common than femoral hernia , a femoral hernia is more likely to strangulate because of the narrowness of the neck and its rigid surrounds.

Pathology

The intestine is obstructed and its blood supply impaired. Initially only the venous return is impeded, the wall of the intestine becomes congested and bright red with the transudation of serous fluid into the sac, the wall becomes purple in colour. The intestinal pressure increases, distending the intestinal loop and impairing venous return further, the arterial supply becomes more and more impaired. Blood is extravasated under the serosa and is effused into the lumen. The fluid in the sac becomes blood stained. At this stage, the wall of the intestine have lost their tone and become friable
Bacterial transudation occurs and the sac fluid becomes infected. Gangrene appears at the rings of constriction, then in the antimesenteric border, the colour varying from black to green. The mesentry also becomes gangrenous. If the strangulation un relieved, perforation of the bowell wall occurs. Peritonitis spreads from the sac to the peritoneal cavity

Clinical features

Sudden pain over the hernia followed by generalized abdominal pain, colicky, mainly at the umbilicus. Nausea and vomiting ensue. May be an increase in hernia size. On examination, the hernia is tense, extremely tender,irreducible and there is no expansile cough impulse
Untreated, the spasms of pain continue until peristaltic contractions cease with the onset of ischaemia, when paralytic ileus(due to peritonitis) and septicemia develop. Spontaneous cessation of pain must be viewed with caution, as this may be a sigh of perforation. So strangulated hernia;
Present with local then general abdominal pain and vomiting
A normal hernia can strangulate at any time
Most common in hernia with narrow necks such as femoral
Require urgent surgery


Strangulated richter,s hernia
Richters hernia is a hernia in which the sac contains only a portion of the circumference of the intestine(usually small intestine). It usually complicate femoral and rarely, obturator hernias
In strangulated richters hernia, the operation is frequently delayed as the clinical features mimic gastroenteritis. The local signs of strangulation are often not obvious, the patient may not vomit, colicky pain is present, the bowel are often opened normally or there may be diarrhea. Absolute constipation is delayed until paralytic ileus supervenes

Strangulated omentocele

The initial symptoms are in general similar to those of strangulated bowel. Vomiting and constipation may be absent. The onset of gangrene usually delayed, occurring first in the centre of the fatty mass. Unrelieved, a bacterial invasion of ischemic contents will occur, abscess develops. In an inguinal hernia, infection usually terminates as a scrotal abscess, extension to the peritoneal cavity is always a possibility

Inflamed hernia

Inflammation can occur from the contents, e.g. acute appendicitis or salpingitis, or from external cause, e.g. trophic ulcer. The hernia is usually tender, but not tense, overlying skin red and oedematous. Treatment by treating the underlying cause

Do hernias usually develop on both sides of the body?

Groin hernias are somewhat more likely to develop on both sides. This is probably because the structural elements develop symmetrically, and the stresses on the body that occur over time are similar on both sides. When a patient becomes aware of a groin swelling on one side, examination by a doctor will often identify a small hernia on the opposite side.

Inguinal hernia

By far the most common hernias (70% ofabdominal hernias). Inguinal hernias are further divided into the more common indirect I h. in which the inguinal hernia is entered via a congenital weakness at its entrance(the internal inguinal ring), this may be caused by failure of embryonic closure of proccesus vaginalis & the direct type where the hernia contents push through a weak spot in the back wall of the inguinal canal (transversalis fascia)

Surgical anatomy

The superficial inguinal ring is a triangular aperture in the aponeurosis of the exterrnal oblique 1.25 cm above the pubic tubercle
The deep inguinal ring is a U-shaped condensation of the transversalis fascia 1.25 cm above the inguinal ligament, midway between the symphysis pubis and the anterior superior iliac spine. The transversalis fascia is the fascial envelop of the abdomen and the competency of the deep ring depends on the integrity of this fascia.
In infants, the superficial and deep ring are superimposed with slight obliquity of the canal. In adults, the inguinal canal about 3.75 cm long, directed downwards and medially from the deep to the superficial ring. In the male, the inguinal canal transmits the spermatic cord, the ilioinguinal nerve and the genital branch of the genitofemoral nerve. In the female, the round ligament replaces the spermatic cord.
The anterior boundary of the inguinal canal comprises the external oblique aponeurosis with the conjoint muscle laterally
The posterior boundary is formed by the fascia transversalis and the conjoint tendon(internal oblique and transverses abdominus medially). The inferior epigastric vessels lie posteriorly and medially to the deep ring
The superior boundary is formed by the conjoint muscles
Inferior boundary is the inguinal ligament
An indirect hernia travels down the canal on the outer(anterolateral) side of the cord. A direct hernia comes out directly forwards through the posterior wall of the canal. The neck of the indirect hernia is lateral to the inferior epigastric vessels, while the diect emerges medial to this except the saddle-bag or pantaloon type which has both a lateral and a medial component. in case of an inguinal hernia the neck is above and medial to the pubic tubercle while that of femoral hernia is below and lateral


Indirect(oblique) inguinal hernia

This is the most common of all hernias, most common in young, while a direct hernia is most common in the old.it occurs up to 20 times more often in men than women (in case of female , the opening of the superficial I. r. is smaller than that of the male, as aresult , the possibility for hernis through the inguinal canal in males is much greater because they have larger opening& therefore a much weaker wall for the intestines to protrude through). In the first decade of life, inguinal hernia is more common on the right side in the male(due to later descent of the right testis and failure of closure of processus vaginalis). In adult males, 55% are right sided and 65% are indirect. The hernia is bilateral in 12%
Three types of indirect inguinal hernia
Bubonocele; the hernia is limited to the inguinal canal
Funicular; the processus vaginalis is closed just above the epididymis. The sac can be felt separately from the testis
Complete(scrotal); the testis appears to lie within the lower part of the hernia

clinical features

When examining apatient from the front with the patient standing with legs apart. The patient is asked to cough, the examiner looks for and feels for the impulse, then addresses the following;
Is the hernia right, left or bilateral?
Is it an inguinal or femoral hernia?
Is it a direct or an indirect hernia?
Is it reducible or irreducible?
Is it incomplete or complete inguinal hernia?
What are the contents?
Males are 20 times more commonly affected than females. Pain in the groin or pain referred to the testicle on heavy work or exercise. When asked to cough, a small transient bulging may be seen. When the sac is small, the bulge may be better seen by observing the hernia site from the side or even looking down the abdominal wall
As an indirect hernia increases in size it becomes apparent when the patient coughs, and persist until reduced. In large hernia, there is a sensation of weight and dragging on the mesentry. This may produce epigastric pain
In infants the swelling appears when the child cries. It can be translucent in infancy and early childhood but never in an adult

Differential diagnosis in the male

Vaginal hydrocele
Encysted hydrocele of the cord
Spermatocele
Femoral hernia
Incompletely descended testis
Lipoma of the cord


Differential diagnosis in the female
Hydrocele of the canal of nuck
Femoral hernia

Treatment

Because inguinal types of hernias are more likely to strangulate, doctors usually repair them surgically when they are diagnosed. If the hernia is incarcerated or strangulated, surgery is performed immediately. Otherwise, repair is done at a time convenient for the person (elective surgery).
A hernia repair requires surgery. There are several different procedures that can be used for fixing any specific type of hernia.

The basic operation for inguinal hernias is inguinal herniotomy( By itself this is sufficient for the infants, adolescents and young adults) which entails dissecting out and opening the hernia sac, reducing any contents and transfixing the neck and removing the remainder.
In adults the operation includs Herniotomy and repair(herniorrhaphy) which consists of;
A. Excision of the hernia sac(herniotomy)
B. Repair of the stretched internal ring and the transversalis fascia
C. Further reinforcement of the posterior wall of the inguinal canal in order to provide a secure repair and avoid the stress on the adjacent tissue caused by pulling the hole closed,

an alternative technique was developed which bridges the hole or weakness with a piece of nonabsorbable prosthetic materials such as polypropylene, polyester mesh.this is widely used now in reparative surgery for abdominal wall hernias. The mesh is a permanent material and, when sewn to the margins of the defect, it allows the body's normal healing process to incorporate it into the local structures. After the initial inflammatory phase, the reaction is followed by an intense deposition of nonspecific fibrotic tissue and concluded by a permanent encapsulation of the alloplastic material in the host's tissues. Hernia repair with mesh has proved to be a very effective means of repair.It is important to remember that prosthetic repair has been proven to have a significant less risk of recurrence than repair with direct sutures.

More and more of hernia repairs are now being done using  HYPERLINK "http://www.medicinenet.com/script/main/art.asp?articlekey=41953" laparoscopic techniques
Hernia operation usually done under general anesthesia which can be very safe. However the surgery can also be performed under local anesthesia or regional anesthetics











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