The abnormal protrusion of a viscus or part of a viscus through a weakness in its containing wall
composition of hernia
Sac - peritoneal lining of hernia; may be complete or incomplete as in sliding
Neck- at the level of the defect in the wall where the hernia emerges
contents- bowel or omentum
Hernias involving the bowel that canno be pushed back into the right place
contents of the hernial sac are stuck inside by adhesions
GI hernias in which bowel contents cannot pass through them - classical features of intestinal obstruction soon appear
If ischaemia occurs - the patient becomes toxic and requires urgent surgery
Abdominal wall weakness
- anatomical - inguinal canal, femoral canal
- acquired - surgical wound, stoma
Increased abdominal pressure
- straining -cough, heavy lifting
- patient processus vaginalis after testicular descent
- Lumps- appears on straining
- nausea/vomitting if obstructed
- severe pain if strangulated
Bowel enters the femoral canal, presenting as a mass in the upper medial thigh or above the inguinal ligament where it points down the leg (unlike inguinal where it points to groin)
Inguinal canal walls
The inguinal canal is made up of
- anterior and posterior walls
- superficial and deep rings
- roof and floor
Deep ring position
Just above the midpoint of the inguinal ligament
Superficial (external ring) position
Superior to the pubic tubercle
Contents of the inguinal canal
- Men - spermatic cord -passes through the inguinal canal to supply and drain the testes
- Women - round ligament of uterus traverse through the canal
Function of inguinal canal
acts as a pathway by which structures can pass from the abdominal wall to the external genitilia
Clinical importance- potential weakness, and a common site of herniation
Mid- Inguinal point definition
Mipoint of the inguinal liganment defintion
Mid-inguinal point - halway between the pubic symphysis and the ASIS - femoral arterty cross into the lower limb at this point
Midpoint of the inguinal ligament - the inguinal ligament runs from the pubic tubercle to teh ASIS so the midpoint is halfway between these structure.
Inguinal hernia types
Direct - A direct inguinal hernia is caused by a weakness in the posterior wall of the inguinal canal. The abdominal contents (usually just fatty tissues, sometimes with bowel) are forced through this defect and enter the inguinal canal. This means that the contents emerge in the canal medial to the deep ring
Indirect- An indirect inguinal hernia, however, does not pierce the posterior wall. The abdominal contents pass through the deep inguinal ring, passing through the inguinal canal and can exit via superficial ring
Epidemiology of inguinal hernias
- commonest type of abdominal hernia
- males > females 8:1
Diagnosis of hernia
- history of lump appearing on straining - often reduces at night
- lump appearing on coughing (stand patient up if not seen)
- reducible into abdomen- may be irreducivble
- herniogram (CT scan with contrast)
- Ultrasound- scrotal lump to exclude hydocoele
Indirect vs direct hernia
- more in females.
- irreducible and strangulate.
- These go down the femoral canal (not the inguinal canal).
- They are usually found below and lateral to the inguinal ligament – this is the opposite of inguinal hernias!
- However, can present above the inguinal ligament as well – but when they do, they will point along the femoral canal, and down the leg, as opposed to towards the groin (like inguinal ones do).
- Repair is recommended for these hernias. -
- These are found just above or just below the umbilicus.
- Omentum or bowel can herniated through them.
- Surgery involves repair of the rectus sheath.
- Risk factors involve obesity and ascites
These appear along lines of previous incision due to surgery. They occur in up to 11-20% of cases of surgery.
Treatment of inguinal hernias
- It is a common sense approach with regards to the management of inguinal hernias. If the lump is small, not increasing in size and is asymptomatic the patient may wish to leave it alone.
- If however the hernia is causing pain, or altering bowel habit then surgical management may be required.
- If the hernial contents become trapped, strangulated, infracted, or obstructed, then this represents a surgical emergency and urgent operative fixation is required.
Both direct and indirect inguinal hernias are repaired in the same way. The main decision to be made is whether to fix the hernia via an open or a laparoscopic technique.
Open inguinal hernia repair
An open technique explores the inguinal canal, identifies the important structures within it (which need to be carefully protected), reduces the hernial contents back into the abdominal cavity and places a mesh that strengthens the posterior wall to prevent further herniation. It is a simple operation with excellent results, and can be done with either general or local anaesthetic.
Laparoscopic inguinal hernia repair
Laparoscopic inguinal hernia repair is also an excellent operation in experienced hands. It has the added benefit of less post-operative pain and quicker recovery, particularly if bilateral hernia repair is performed. The basic steps of the operation involve visualising the defect from within the abdominal cavity, reducing or pulling back the contents of the hernia, and repairing the defect from within the abdomen.
treatment of hernias
- elective surgical repair- hernia contents returned to abdomen and defect repaired with sutures or artifical mesh
- may be possible to perform laparoscopically
- emergency repiar if incarcerated ir strangulated
- if strangulated may need bowel resection
- external pressure (truss) only if unfit for surgery